multi_buffer.rs

   1mod anchor;
   2#[cfg(test)]
   3mod multi_buffer_tests;
   4mod path_key;
   5mod transaction;
   6
   7use self::transaction::History;
   8
   9pub use anchor::{Anchor, AnchorRangeExt};
  10
  11use anyhow::{Result, anyhow};
  12use buffer_diff::{
  13    BufferDiff, BufferDiffEvent, BufferDiffSnapshot, DiffChanged, DiffHunkSecondaryStatus,
  14    DiffHunkStatus, DiffHunkStatusKind,
  15};
  16use clock::ReplicaId;
  17use collections::{BTreeMap, Bound, HashMap, HashSet};
  18use gpui::{App, Context, Entity, EventEmitter};
  19use itertools::Itertools;
  20use language::{
  21    AutoindentMode, BracketMatch, Buffer, BufferChunks, BufferRow, BufferSnapshot, Capability,
  22    CharClassifier, CharKind, CharScopeContext, Chunk, CursorShape, DiagnosticEntryRef, File,
  23    IndentGuideSettings, IndentSize, Language, LanguageScope, OffsetRangeExt, OffsetUtf16, Outline,
  24    OutlineItem, Point, PointUtf16, Selection, TextDimension, TextObject, ToOffset as _,
  25    ToPoint as _, TransactionId, TreeSitterOptions, Unclipped,
  26    language_settings::{LanguageSettings, language_settings},
  27};
  28
  29#[cfg(any(test, feature = "test-support"))]
  30use gpui::AppContext as _;
  31
  32use rope::DimensionPair;
  33use smallvec::SmallVec;
  34use smol::future::yield_now;
  35use std::{
  36    any::type_name,
  37    borrow::Cow,
  38    cell::{Cell, OnceCell, Ref, RefCell},
  39    cmp::{self, Ordering},
  40    fmt,
  41    future::Future,
  42    io,
  43    iter::{self, FromIterator},
  44    mem,
  45    ops::{self, Add, AddAssign, ControlFlow, Range, RangeBounds, Sub, SubAssign},
  46    rc::Rc,
  47    str,
  48    sync::{Arc, OnceLock},
  49    time::Duration,
  50};
  51use sum_tree::{Bias, Cursor, Dimension, Dimensions, SumTree, TreeMap};
  52use text::{
  53    BufferId, Edit, LineIndent, TextSummary,
  54    locator::Locator,
  55    subscription::{Subscription, Topic},
  56};
  57use theme::SyntaxTheme;
  58use ztracing::instrument;
  59
  60pub use self::path_key::{PathExcerptInsertResult, PathKey};
  61
  62pub static EXCERPT_CONTEXT_LINES: OnceLock<fn(&App) -> u32> = OnceLock::new();
  63
  64pub fn excerpt_context_lines(cx: &App) -> u32 {
  65    EXCERPT_CONTEXT_LINES.get().map(|f| f(cx)).unwrap_or(2)
  66}
  67
  68/// One or more [`Buffers`](Buffer) being edited in a single view.
  69///
  70/// See <https://zed.dev/features#multi-buffers>
  71pub struct MultiBuffer {
  72    /// A snapshot of the [`Excerpt`]s in the MultiBuffer.
  73    /// Use [`MultiBuffer::snapshot`] to get a up-to-date snapshot.
  74    snapshot: RefCell<MultiBufferSnapshot>,
  75    /// Contains the state of the buffers being edited
  76    buffers: BTreeMap<BufferId, BufferState>,
  77    /// Mapping from buffer IDs to their diff states
  78    diffs: HashMap<BufferId, DiffState>,
  79    subscriptions: Topic<MultiBufferOffset>,
  80    /// If true, the multi-buffer only contains a single [`Buffer`] and a single [`Excerpt`]
  81    singleton: bool,
  82    /// The history of the multi-buffer.
  83    history: History,
  84    /// The explicit title of the multi-buffer.
  85    /// If `None`, it will be derived from the underlying path or content.
  86    title: Option<String>,
  87    /// The writing capability of the multi-buffer.
  88    capability: Capability,
  89    buffer_changed_since_sync: Rc<Cell<bool>>,
  90}
  91
  92pub struct ExcerptInfo {
  93    path_key: PathKey,
  94    buffer_id: BufferId,
  95    range: ExcerptRange<text::Anchor>,
  96}
  97
  98#[derive(Clone, Debug, PartialEq, Eq)]
  99pub enum Event {
 100    BufferUpdated {
 101        buffer: Entity<Buffer>,
 102        path_key: PathKey,
 103        ranges: Vec<Range<text::Anchor>>,
 104    },
 105    BuffersRemoved {
 106        removed_buffer_ids: Vec<BufferId>,
 107    },
 108    BuffersEdited {
 109        buffer_ids: Vec<BufferId>,
 110    },
 111    DiffHunksToggled,
 112    Edited {
 113        edited_buffer: Option<Entity<Buffer>>,
 114    },
 115    TransactionUndone {
 116        transaction_id: TransactionId,
 117    },
 118    Reloaded,
 119    LanguageChanged(BufferId, bool),
 120    Reparsed(BufferId),
 121    Saved,
 122    FileHandleChanged,
 123    DirtyChanged,
 124    DiagnosticsUpdated,
 125    BufferDiffChanged,
 126}
 127
 128/// A diff hunk, representing a range of consequent lines in a multibuffer.
 129#[derive(Debug, Clone, PartialEq, Eq)]
 130pub struct MultiBufferDiffHunk {
 131    /// The row range in the multibuffer where this diff hunk appears.
 132    pub row_range: Range<MultiBufferRow>,
 133    /// The buffer ID that this hunk belongs to.
 134    pub buffer_id: BufferId,
 135    /// The range of the underlying buffer that this hunk corresponds to.
 136    pub buffer_range: Range<text::Anchor>,
 137    /// The range within the buffer's diff base that this hunk corresponds to.
 138    pub diff_base_byte_range: Range<BufferOffset>,
 139    /// The status of this hunk (added/modified/deleted and secondary status).
 140    pub status: DiffHunkStatus,
 141    /// The word diffs for this hunk.
 142    pub word_diffs: Vec<Range<MultiBufferOffset>>,
 143}
 144
 145impl MultiBufferDiffHunk {
 146    pub fn status(&self) -> DiffHunkStatus {
 147        self.status
 148    }
 149
 150    pub fn is_created_file(&self) -> bool {
 151        self.diff_base_byte_range == (BufferOffset(0)..BufferOffset(0))
 152            && self.buffer_range.start.is_min()
 153            && self.buffer_range.end.is_max()
 154    }
 155
 156    pub fn multi_buffer_range(&self) -> Range<Anchor> {
 157        let start = Anchor::text(self.buffer_range.start);
 158        let end = Anchor::text(self.buffer_range.end);
 159        start..end
 160    }
 161}
 162
 163pub type MultiBufferPoint = Point;
 164type ExcerptOffset = ExcerptDimension<MultiBufferOffset>;
 165type ExcerptPoint = ExcerptDimension<Point>;
 166
 167#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 168#[serde(transparent)]
 169pub struct MultiBufferRow(pub u32);
 170
 171impl MultiBufferRow {
 172    pub const MIN: Self = Self(0);
 173    pub const MAX: Self = Self(u32::MAX);
 174}
 175
 176impl ops::Add<usize> for MultiBufferRow {
 177    type Output = Self;
 178
 179    fn add(self, rhs: usize) -> Self::Output {
 180        MultiBufferRow(self.0 + rhs as u32)
 181    }
 182}
 183
 184pub trait MultiBufferDimension: 'static + Copy + Default + std::fmt::Debug {
 185    type TextDimension: TextDimension;
 186    fn from_summary(summary: &MBTextSummary) -> Self;
 187
 188    fn add_text_dim(&mut self, summary: &Self::TextDimension);
 189
 190    fn add_mb_text_summary(&mut self, summary: &MBTextSummary);
 191}
 192
 193// todo(lw): MultiBufferPoint
 194impl MultiBufferDimension for Point {
 195    type TextDimension = Point;
 196    fn from_summary(summary: &MBTextSummary) -> Self {
 197        summary.lines
 198    }
 199
 200    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 201        *self += *other;
 202    }
 203
 204    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 205        *self += summary.lines;
 206    }
 207}
 208
 209// todo(lw): MultiBufferPointUtf16
 210impl MultiBufferDimension for PointUtf16 {
 211    type TextDimension = PointUtf16;
 212    fn from_summary(summary: &MBTextSummary) -> Self {
 213        summary.lines_utf16()
 214    }
 215
 216    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 217        *self += *other;
 218    }
 219
 220    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 221        *self += summary.lines_utf16();
 222    }
 223}
 224
 225#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 226pub struct MultiBufferOffset(pub usize);
 227
 228impl fmt::Display for MultiBufferOffset {
 229    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 230        write!(f, "{}", self.0)
 231    }
 232}
 233
 234impl rand::distr::uniform::SampleUniform for MultiBufferOffset {
 235    type Sampler = MultiBufferOffsetUniformSampler;
 236}
 237
 238pub struct MultiBufferOffsetUniformSampler {
 239    sampler: rand::distr::uniform::UniformUsize,
 240}
 241
 242impl rand::distr::uniform::UniformSampler for MultiBufferOffsetUniformSampler {
 243    type X = MultiBufferOffset;
 244
 245    fn new<B1, B2>(low_b: B1, high_b: B2) -> Result<Self, rand::distr::uniform::Error>
 246    where
 247        B1: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 248        B2: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 249    {
 250        let low = *low_b.borrow();
 251        let high = *high_b.borrow();
 252        let sampler = rand::distr::uniform::UniformUsize::new(low.0, high.0);
 253        sampler.map(|sampler| MultiBufferOffsetUniformSampler { sampler })
 254    }
 255
 256    #[inline] // if the range is constant, this helps LLVM to do the
 257    // calculations at compile-time.
 258    fn new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> Result<Self, rand::distr::uniform::Error>
 259    where
 260        B1: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 261        B2: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 262    {
 263        let low = *low_b.borrow();
 264        let high = *high_b.borrow();
 265        let sampler = rand::distr::uniform::UniformUsize::new_inclusive(low.0, high.0);
 266        sampler.map(|sampler| MultiBufferOffsetUniformSampler { sampler })
 267    }
 268
 269    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> Self::X {
 270        MultiBufferOffset(self.sampler.sample(rng))
 271    }
 272}
 273impl MultiBufferDimension for MultiBufferOffset {
 274    type TextDimension = usize;
 275    fn from_summary(summary: &MBTextSummary) -> Self {
 276        summary.len
 277    }
 278
 279    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 280        self.0 += *other;
 281    }
 282
 283    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 284        *self += summary.len;
 285    }
 286}
 287impl MultiBufferDimension for MultiBufferOffsetUtf16 {
 288    type TextDimension = OffsetUtf16;
 289    fn from_summary(summary: &MBTextSummary) -> Self {
 290        MultiBufferOffsetUtf16(summary.len_utf16)
 291    }
 292
 293    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 294        self.0 += *other;
 295    }
 296
 297    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 298        self.0 += summary.len_utf16;
 299    }
 300}
 301
 302#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 303pub struct BufferOffset(pub usize);
 304
 305impl TextDimension for BufferOffset {
 306    fn from_text_summary(summary: &TextSummary) -> Self {
 307        BufferOffset(usize::from_text_summary(summary))
 308    }
 309    fn from_chunk(chunk: rope::ChunkSlice) -> Self {
 310        BufferOffset(usize::from_chunk(chunk))
 311    }
 312    fn add_assign(&mut self, other: &Self) {
 313        TextDimension::add_assign(&mut self.0, &other.0);
 314    }
 315}
 316impl<'a> sum_tree::Dimension<'a, rope::ChunkSummary> for BufferOffset {
 317    fn zero(cx: ()) -> Self {
 318        BufferOffset(<usize as sum_tree::Dimension<'a, rope::ChunkSummary>>::zero(cx))
 319    }
 320
 321    fn add_summary(&mut self, summary: &'a rope::ChunkSummary, cx: ()) {
 322        usize::add_summary(&mut self.0, summary, cx);
 323    }
 324}
 325
 326impl Sub for BufferOffset {
 327    type Output = usize;
 328
 329    fn sub(self, other: BufferOffset) -> Self::Output {
 330        self.0 - other.0
 331    }
 332}
 333
 334impl AddAssign<DimensionPair<usize, Point>> for BufferOffset {
 335    fn add_assign(&mut self, other: DimensionPair<usize, Point>) {
 336        self.0 += other.key;
 337    }
 338}
 339
 340impl language::ToPoint for BufferOffset {
 341    fn to_point(&self, snapshot: &text::BufferSnapshot) -> Point {
 342        self.0.to_point(snapshot)
 343    }
 344}
 345
 346impl language::ToPointUtf16 for BufferOffset {
 347    fn to_point_utf16(&self, snapshot: &text::BufferSnapshot) -> PointUtf16 {
 348        self.0.to_point_utf16(snapshot)
 349    }
 350}
 351
 352impl language::ToOffset for BufferOffset {
 353    fn to_offset(&self, snapshot: &text::BufferSnapshot) -> usize {
 354        self.0.to_offset(snapshot)
 355    }
 356}
 357
 358impl language::ToOffsetUtf16 for BufferOffset {
 359    fn to_offset_utf16(&self, snapshot: &text::BufferSnapshot) -> OffsetUtf16 {
 360        self.0.to_offset_utf16(snapshot)
 361    }
 362}
 363
 364#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
 365pub struct MultiBufferOffsetUtf16(pub OffsetUtf16);
 366
 367impl ops::Add<usize> for MultiBufferOffsetUtf16 {
 368    type Output = MultiBufferOffsetUtf16;
 369
 370    fn add(self, rhs: usize) -> Self::Output {
 371        MultiBufferOffsetUtf16(OffsetUtf16(self.0.0 + rhs))
 372    }
 373}
 374
 375impl ops::Add<OffsetUtf16> for MultiBufferOffsetUtf16 {
 376    type Output = Self;
 377
 378    fn add(self, rhs: OffsetUtf16) -> Self::Output {
 379        MultiBufferOffsetUtf16(self.0 + rhs)
 380    }
 381}
 382
 383impl AddAssign<OffsetUtf16> for MultiBufferOffsetUtf16 {
 384    fn add_assign(&mut self, rhs: OffsetUtf16) {
 385        self.0 += rhs;
 386    }
 387}
 388
 389impl AddAssign<usize> for MultiBufferOffsetUtf16 {
 390    fn add_assign(&mut self, rhs: usize) {
 391        self.0.0 += rhs;
 392    }
 393}
 394
 395impl Sub for MultiBufferOffsetUtf16 {
 396    type Output = OffsetUtf16;
 397
 398    fn sub(self, other: MultiBufferOffsetUtf16) -> Self::Output {
 399        self.0 - other.0
 400    }
 401}
 402
 403impl Sub<OffsetUtf16> for MultiBufferOffsetUtf16 {
 404    type Output = MultiBufferOffsetUtf16;
 405
 406    fn sub(self, other: OffsetUtf16) -> Self::Output {
 407        MultiBufferOffsetUtf16(self.0 - other)
 408    }
 409}
 410
 411#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
 412pub struct BufferOffsetUtf16(pub OffsetUtf16);
 413
 414impl MultiBufferOffset {
 415    const ZERO: Self = Self(0);
 416    pub fn saturating_sub(self, other: MultiBufferOffset) -> usize {
 417        self.0.saturating_sub(other.0)
 418    }
 419    pub fn saturating_sub_usize(self, other: usize) -> MultiBufferOffset {
 420        MultiBufferOffset(self.0.saturating_sub(other))
 421    }
 422}
 423
 424impl ops::Sub for MultiBufferOffset {
 425    type Output = usize;
 426
 427    fn sub(self, other: MultiBufferOffset) -> Self::Output {
 428        self.0 - other.0
 429    }
 430}
 431
 432impl ops::Sub<usize> for MultiBufferOffset {
 433    type Output = Self;
 434
 435    fn sub(self, other: usize) -> Self::Output {
 436        MultiBufferOffset(self.0 - other)
 437    }
 438}
 439
 440impl ops::SubAssign<usize> for MultiBufferOffset {
 441    fn sub_assign(&mut self, other: usize) {
 442        self.0 -= other;
 443    }
 444}
 445
 446impl ops::Add<usize> for BufferOffset {
 447    type Output = Self;
 448
 449    fn add(self, rhs: usize) -> Self::Output {
 450        BufferOffset(self.0 + rhs)
 451    }
 452}
 453
 454impl ops::AddAssign<usize> for BufferOffset {
 455    fn add_assign(&mut self, other: usize) {
 456        self.0 += other;
 457    }
 458}
 459
 460impl ops::Add<usize> for MultiBufferOffset {
 461    type Output = Self;
 462
 463    fn add(self, rhs: usize) -> Self::Output {
 464        MultiBufferOffset(self.0 + rhs)
 465    }
 466}
 467
 468impl ops::AddAssign<usize> for MultiBufferOffset {
 469    fn add_assign(&mut self, other: usize) {
 470        self.0 += other;
 471    }
 472}
 473
 474impl ops::Add<isize> for MultiBufferOffset {
 475    type Output = Self;
 476
 477    fn add(self, rhs: isize) -> Self::Output {
 478        MultiBufferOffset((self.0 as isize + rhs) as usize)
 479    }
 480}
 481
 482impl ops::Add for MultiBufferOffset {
 483    type Output = Self;
 484
 485    fn add(self, rhs: MultiBufferOffset) -> Self::Output {
 486        MultiBufferOffset(self.0 + rhs.0)
 487    }
 488}
 489
 490impl ops::AddAssign<MultiBufferOffset> for MultiBufferOffset {
 491    fn add_assign(&mut self, other: MultiBufferOffset) {
 492        self.0 += other.0;
 493    }
 494}
 495
 496pub trait ToOffset: 'static + fmt::Debug {
 497    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset;
 498    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16;
 499}
 500
 501pub trait ToPoint: 'static + fmt::Debug {
 502    fn to_point(&self, snapshot: &MultiBufferSnapshot) -> Point;
 503    fn to_point_utf16(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16;
 504}
 505
 506struct BufferState {
 507    buffer: Entity<Buffer>,
 508    path_key: PathKey,
 509    last_version: RefCell<clock::Global>,
 510    last_non_text_state_update_count: Cell<usize>,
 511    _subscriptions: [gpui::Subscription; 2],
 512}
 513
 514struct DiffState {
 515    diff: Entity<BufferDiff>,
 516    main_buffer: Option<Entity<language::Buffer>>,
 517    _subscription: gpui::Subscription,
 518}
 519
 520impl DiffState {
 521    fn snapshot(&self, cx: &App) -> DiffStateSnapshot {
 522        DiffStateSnapshot {
 523            diff: self.diff.read(cx).snapshot(cx),
 524            main_buffer: self.main_buffer.as_ref().map(|b| b.read(cx).snapshot()),
 525        }
 526    }
 527}
 528
 529#[derive(Clone)]
 530struct DiffStateSnapshot {
 531    diff: BufferDiffSnapshot,
 532    main_buffer: Option<language::BufferSnapshot>,
 533}
 534
 535impl std::ops::Deref for DiffStateSnapshot {
 536    type Target = BufferDiffSnapshot;
 537
 538    fn deref(&self) -> &Self::Target {
 539        &self.diff
 540    }
 541}
 542
 543impl DiffState {
 544    fn new(diff: Entity<BufferDiff>, cx: &mut Context<MultiBuffer>) -> Self {
 545        DiffState {
 546            _subscription: cx.subscribe(&diff, |this, diff, event, cx| match event {
 547                BufferDiffEvent::DiffChanged(DiffChanged {
 548                    changed_range,
 549                    base_text_changed_range: _,
 550                    extended_range,
 551                }) => {
 552                    let use_extended = this.snapshot.borrow().use_extended_diff_range;
 553                    let range = if use_extended {
 554                        extended_range.clone()
 555                    } else {
 556                        changed_range.clone()
 557                    };
 558                    if let Some(range) = range {
 559                        this.buffer_diff_changed(diff, range, cx)
 560                    }
 561                    cx.emit(Event::BufferDiffChanged);
 562                }
 563                BufferDiffEvent::LanguageChanged => this.buffer_diff_language_changed(diff, cx),
 564                _ => {}
 565            }),
 566            diff,
 567            main_buffer: None,
 568        }
 569    }
 570
 571    fn new_inverted(
 572        diff: Entity<BufferDiff>,
 573        main_buffer: Entity<language::Buffer>,
 574        cx: &mut Context<MultiBuffer>,
 575    ) -> Self {
 576        let weak_main_buffer = main_buffer.downgrade();
 577        DiffState {
 578            _subscription: cx.subscribe(&diff, {
 579                move |this, diff, event, cx| {
 580                    let Some(main_buffer) = weak_main_buffer.upgrade() else {
 581                        return;
 582                    };
 583                    match event {
 584                        BufferDiffEvent::DiffChanged(DiffChanged {
 585                            changed_range: _,
 586                            base_text_changed_range,
 587                            extended_range: _,
 588                        }) => {
 589                            this.inverted_buffer_diff_changed(
 590                                diff,
 591                                main_buffer,
 592                                base_text_changed_range.clone(),
 593                                cx,
 594                            );
 595                            cx.emit(Event::BufferDiffChanged);
 596                        }
 597                        BufferDiffEvent::LanguageChanged => {
 598                            this.inverted_buffer_diff_language_changed(diff, main_buffer, cx)
 599                        }
 600                        _ => {}
 601                    }
 602                }
 603            }),
 604            diff,
 605            main_buffer: Some(main_buffer),
 606        }
 607    }
 608}
 609
 610/// The contents of a [`MultiBuffer`] at a single point in time.
 611#[derive(Clone, Default)]
 612pub struct MultiBufferSnapshot {
 613    excerpts: SumTree<Excerpt>,
 614    path_keys: TreeMap<BufferId, PathKey>,
 615    diffs: TreeMap<BufferId, DiffStateSnapshot>,
 616    diff_transforms: SumTree<DiffTransform>,
 617    non_text_state_update_count: usize,
 618    edit_count: usize,
 619    is_dirty: bool,
 620    has_deleted_file: bool,
 621    has_conflict: bool,
 622    has_inverted_diff: bool,
 623    singleton: bool,
 624    trailing_excerpt_update_count: usize,
 625    all_diff_hunks_expanded: bool,
 626    show_deleted_hunks: bool,
 627    use_extended_diff_range: bool,
 628    show_headers: bool,
 629}
 630
 631#[derive(Debug, Clone)]
 632enum DiffTransform {
 633    BufferContent {
 634        summary: MBTextSummary,
 635        inserted_hunk_info: Option<DiffTransformHunkInfo>,
 636    },
 637    DeletedHunk {
 638        summary: TextSummary,
 639        buffer_id: BufferId,
 640        hunk_info: DiffTransformHunkInfo,
 641        base_text_byte_range: Range<usize>,
 642        has_trailing_newline: bool,
 643    },
 644}
 645
 646#[derive(Clone, Copy, Debug)]
 647struct DiffTransformHunkInfo {
 648    buffer_id: BufferId,
 649    hunk_start_anchor: text::Anchor,
 650    hunk_secondary_status: DiffHunkSecondaryStatus,
 651    is_logically_deleted: bool,
 652}
 653
 654impl Eq for DiffTransformHunkInfo {}
 655
 656impl PartialEq for DiffTransformHunkInfo {
 657    fn eq(&self, other: &DiffTransformHunkInfo) -> bool {
 658        self.buffer_id == other.buffer_id && self.hunk_start_anchor == other.hunk_start_anchor
 659    }
 660}
 661
 662impl std::hash::Hash for DiffTransformHunkInfo {
 663    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
 664        self.buffer_id.hash(state);
 665        self.hunk_start_anchor.hash(state);
 666    }
 667}
 668
 669#[derive(Clone)]
 670pub struct ExcerptBoundaryInfo {
 671    pub buffer: Arc<BufferSnapshot>,
 672    pub buffer_id: BufferId,
 673    pub range: ExcerptRange<text::Anchor>,
 674    pub end_row: MultiBufferRow,
 675}
 676
 677impl std::fmt::Debug for ExcerptBoundaryInfo {
 678    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 679        f.debug_struct(type_name::<Self>())
 680            .field("buffer_id", &self.buffer_id)
 681            .field("path", &self.buffer.file().map(|f| f.path()))
 682            .field("range", &self.range)
 683            .finish()
 684    }
 685}
 686
 687/// A boundary between `Excerpt`s in a [`MultiBuffer`]
 688#[derive(Debug)]
 689pub struct ExcerptBoundary {
 690    pub prev: Option<ExcerptBoundaryInfo>,
 691    pub next: ExcerptBoundaryInfo,
 692    /// The row in the `MultiBuffer` where the boundary is located
 693    pub row: MultiBufferRow,
 694}
 695
 696impl ExcerptBoundary {
 697    pub fn starts_new_buffer(&self) -> bool {
 698        match (self.prev.as_ref(), &self.next) {
 699            (None, _) => true,
 700            (Some(prev), next) => prev.buffer_id != next.buffer_id,
 701        }
 702    }
 703}
 704
 705#[derive(Clone, Debug, PartialEq, Eq)]
 706pub struct ExpandInfo {
 707    pub direction: ExpandExcerptDirection,
 708    pub excerpt_range: Range<text::Anchor>,
 709}
 710
 711#[derive(Clone, Debug, Default, PartialEq, Eq)]
 712pub struct RowInfo {
 713    pub buffer_id: Option<BufferId>,
 714    pub buffer_row: Option<u32>,
 715    pub multibuffer_row: Option<MultiBufferRow>,
 716    pub diff_status: Option<buffer_diff::DiffHunkStatus>,
 717    pub expand_info: Option<ExpandInfo>,
 718    pub wrapped_buffer_row: Option<u32>,
 719}
 720
 721/// A slice into a [`Buffer`] that is being edited in a [`MultiBuffer`].
 722#[derive(Clone)]
 723pub(crate) struct Excerpt {
 724    /// The location of the excerpt in the [`MultiBuffer`]
 725    pub(crate) path_key: PathKey,
 726    /// A snapshot of the buffer being excerpted
 727    pub(crate) buffer: Arc<BufferSnapshot>,
 728    /// The range of the buffer to be shown in the excerpt
 729    pub(crate) range: ExcerptRange<text::Anchor>,
 730
 731    /// The last row in the excerpted slice of the buffer
 732    pub(crate) max_buffer_row: BufferRow,
 733    /// A summary of the text in the excerpt
 734    pub(crate) text_summary: TextSummary,
 735    pub(crate) has_trailing_newline: bool,
 736}
 737
 738/// A public view into an `Excerpt` in a [`MultiBuffer`].
 739///
 740/// Contains methods for getting the [`Buffer`] of the excerpt,
 741/// as well as mapping offsets to/from buffer and multibuffer coordinates.
 742#[derive(Clone)]
 743pub struct MultiBufferExcerpt<'a> {
 744    excerpt: &'a Excerpt,
 745    diff_transforms:
 746        sum_tree::Cursor<'a, 'static, DiffTransform, DiffTransforms<MultiBufferOffset>>,
 747    /// The offset in the multibuffer considering diff transforms.
 748    offset: MultiBufferOffset,
 749    /// The offset in the multibuffer without diff transforms.
 750    excerpt_offset: ExcerptOffset,
 751    buffer_offset: BufferOffset,
 752}
 753
 754/// A range of text from a single [`Buffer`], to be shown as an `Excerpt`.
 755/// These ranges are relative to the buffer itself
 756#[derive(Clone, Debug, Eq, PartialEq, Hash)]
 757pub struct ExcerptRange<T> {
 758    /// The full range of text to be shown in the excerpt.
 759    pub context: Range<T>,
 760    /// The primary range of text to be highlighted in the excerpt.
 761    /// In a multi-buffer search, this would be the text that matched the search
 762    pub primary: Range<T>,
 763}
 764
 765impl<T: Clone> ExcerptRange<T> {
 766    pub fn new(context: Range<T>) -> Self {
 767        Self {
 768            context: context.clone(),
 769            primary: context,
 770        }
 771    }
 772}
 773
 774impl ExcerptRange<text::Anchor> {
 775    pub fn contains(&self, t: &text::Anchor, snapshot: &BufferSnapshot) -> bool {
 776        self.context.start.cmp(t, snapshot).is_le() && self.context.end.cmp(t, snapshot).is_ge()
 777    }
 778}
 779
 780#[derive(Clone, Debug)]
 781pub struct ExcerptSummary {
 782    path_key: PathKey,
 783    /// End of the excerpt
 784    max_anchor: text::Anchor,
 785    widest_line_number: u32,
 786    text: MBTextSummary,
 787    count: usize,
 788}
 789
 790impl ExcerptSummary {
 791    pub fn min() -> Self {
 792        ExcerptSummary {
 793            path_key: PathKey::min(),
 794            max_anchor: text::Anchor::MIN,
 795            widest_line_number: 0,
 796            text: MBTextSummary::default(),
 797            count: 0,
 798        }
 799    }
 800}
 801
 802#[derive(Debug, Clone)]
 803pub struct DiffTransformSummary {
 804    input: MBTextSummary,
 805    output: MBTextSummary,
 806}
 807
 808/// Summary of a string of text.
 809#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 810pub struct MBTextSummary {
 811    /// Length in bytes.
 812    pub len: MultiBufferOffset,
 813    /// Length in UTF-8.
 814    pub chars: usize,
 815    /// Length in UTF-16 code units
 816    pub len_utf16: OffsetUtf16,
 817    /// A point representing the number of lines and the length of the last line.
 818    ///
 819    /// In other words, it marks the point after the last byte in the text, (if
 820    /// EOF was a character, this would be its position).
 821    pub lines: Point,
 822    /// How many `char`s are in the first line
 823    pub first_line_chars: u32,
 824    /// How many `char`s are in the last line
 825    pub last_line_chars: u32,
 826    /// How many UTF-16 code units are in the last line
 827    pub last_line_len_utf16: u32,
 828    /// The row idx of the longest row
 829    pub longest_row: u32,
 830    /// How many `char`s are in the longest row
 831    pub longest_row_chars: u32,
 832}
 833
 834impl From<TextSummary> for MBTextSummary {
 835    fn from(summary: TextSummary) -> Self {
 836        MBTextSummary {
 837            len: MultiBufferOffset(summary.len),
 838            chars: summary.chars,
 839            len_utf16: summary.len_utf16,
 840            lines: summary.lines,
 841            first_line_chars: summary.first_line_chars,
 842            last_line_chars: summary.last_line_chars,
 843            last_line_len_utf16: summary.last_line_len_utf16,
 844            longest_row: summary.longest_row,
 845            longest_row_chars: summary.longest_row_chars,
 846        }
 847    }
 848}
 849
 850impl From<MBTextSummary> for TextSummary {
 851    fn from(summary: MBTextSummary) -> Self {
 852        TextSummary {
 853            len: summary.len.0,
 854            chars: summary.chars,
 855            len_utf16: summary.len_utf16,
 856            lines: summary.lines,
 857            first_line_chars: summary.first_line_chars,
 858            last_line_chars: summary.last_line_chars,
 859            last_line_len_utf16: summary.last_line_len_utf16,
 860            longest_row: summary.longest_row,
 861            longest_row_chars: summary.longest_row_chars,
 862        }
 863    }
 864}
 865
 866impl From<&str> for MBTextSummary {
 867    fn from(text: &str) -> Self {
 868        MBTextSummary::from(TextSummary::from(text))
 869    }
 870}
 871
 872impl MultiBufferDimension for MBTextSummary {
 873    type TextDimension = TextSummary;
 874
 875    fn from_summary(summary: &MBTextSummary) -> Self {
 876        *summary
 877    }
 878
 879    fn add_text_dim(&mut self, summary: &Self::TextDimension) {
 880        *self += *summary;
 881    }
 882
 883    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 884        *self += *summary;
 885    }
 886}
 887
 888impl AddAssign for MBTextSummary {
 889    fn add_assign(&mut self, other: MBTextSummary) {
 890        let joined_chars = self.last_line_chars + other.first_line_chars;
 891        if joined_chars > self.longest_row_chars {
 892            self.longest_row = self.lines.row;
 893            self.longest_row_chars = joined_chars;
 894        }
 895        if other.longest_row_chars > self.longest_row_chars {
 896            self.longest_row = self.lines.row + other.longest_row;
 897            self.longest_row_chars = other.longest_row_chars;
 898        }
 899
 900        if self.lines.row == 0 {
 901            self.first_line_chars += other.first_line_chars;
 902        }
 903
 904        if other.lines.row == 0 {
 905            self.last_line_chars += other.first_line_chars;
 906            self.last_line_len_utf16 += other.last_line_len_utf16;
 907        } else {
 908            self.last_line_chars = other.last_line_chars;
 909            self.last_line_len_utf16 = other.last_line_len_utf16;
 910        }
 911
 912        self.chars += other.chars;
 913        self.len += other.len;
 914        self.len_utf16 += other.len_utf16;
 915        self.lines += other.lines;
 916    }
 917}
 918
 919impl AddAssign<TextSummary> for MBTextSummary {
 920    fn add_assign(&mut self, other: TextSummary) {
 921        *self += MBTextSummary::from(other);
 922    }
 923}
 924
 925impl MBTextSummary {
 926    pub fn lines_utf16(&self) -> PointUtf16 {
 927        PointUtf16 {
 928            row: self.lines.row,
 929            column: self.last_line_len_utf16,
 930        }
 931    }
 932}
 933
 934impl<K, V> MultiBufferDimension for DimensionPair<K, V>
 935where
 936    K: MultiBufferDimension,
 937    V: MultiBufferDimension,
 938{
 939    type TextDimension = DimensionPair<K::TextDimension, V::TextDimension>;
 940
 941    fn from_summary(summary: &MBTextSummary) -> Self {
 942        Self {
 943            key: K::from_summary(summary),
 944            value: Some(V::from_summary(summary)),
 945        }
 946    }
 947
 948    fn add_text_dim(&mut self, summary: &Self::TextDimension) {
 949        self.key.add_text_dim(&summary.key);
 950        if let Some(value) = &mut self.value {
 951            if let Some(other_value) = summary.value.as_ref() {
 952                value.add_text_dim(other_value);
 953            }
 954        }
 955    }
 956
 957    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 958        self.key.add_mb_text_summary(summary);
 959        if let Some(value) = &mut self.value {
 960            value.add_mb_text_summary(summary);
 961        }
 962    }
 963}
 964
 965#[derive(Clone)]
 966pub struct MultiBufferRows<'a> {
 967    point: Point,
 968    is_empty: bool,
 969    is_singleton: bool,
 970    cursor: MultiBufferCursor<'a, Point, Point>,
 971}
 972
 973pub struct MultiBufferChunks<'a> {
 974    excerpts: Cursor<'a, 'static, Excerpt, ExcerptOffset>,
 975    diff_transforms:
 976        Cursor<'a, 'static, DiffTransform, Dimensions<MultiBufferOffset, ExcerptOffset>>,
 977    diffs: &'a TreeMap<BufferId, DiffStateSnapshot>,
 978    diff_base_chunks: Option<(BufferId, BufferChunks<'a>)>,
 979    buffer_chunk: Option<Chunk<'a>>,
 980    range: Range<MultiBufferOffset>,
 981    excerpt_offset_range: Range<ExcerptOffset>,
 982    excerpt_chunks: Option<ExcerptChunks<'a>>,
 983    language_aware: bool,
 984}
 985
 986pub struct ReversedMultiBufferChunks<'a> {
 987    cursor: MultiBufferCursor<'a, MultiBufferOffset, BufferOffset>,
 988    current_chunks: Option<rope::Chunks<'a>>,
 989    start: MultiBufferOffset,
 990    offset: MultiBufferOffset,
 991}
 992
 993pub struct MultiBufferBytes<'a> {
 994    range: Range<MultiBufferOffset>,
 995    cursor: MultiBufferCursor<'a, MultiBufferOffset, BufferOffset>,
 996    excerpt_bytes: Option<text::Bytes<'a>>,
 997    has_trailing_newline: bool,
 998    chunk: &'a [u8],
 999}
1000
1001pub struct ReversedMultiBufferBytes<'a> {
1002    range: Range<MultiBufferOffset>,
1003    chunks: ReversedMultiBufferChunks<'a>,
1004    chunk: &'a [u8],
1005}
1006
1007#[derive(Clone)]
1008struct DiffTransforms<MBD> {
1009    output_dimension: OutputDimension<MBD>,
1010    excerpt_dimension: ExcerptDimension<MBD>,
1011}
1012
1013impl<'a, MBD: MultiBufferDimension> Dimension<'a, DiffTransformSummary> for DiffTransforms<MBD> {
1014    fn zero(cx: <DiffTransformSummary as sum_tree::Summary>::Context<'_>) -> Self {
1015        Self {
1016            output_dimension: OutputDimension::zero(cx),
1017            excerpt_dimension: <ExcerptDimension<MBD> as Dimension<'a, DiffTransformSummary>>::zero(
1018                cx,
1019            ),
1020        }
1021    }
1022
1023    fn add_summary(
1024        &mut self,
1025        summary: &'a DiffTransformSummary,
1026        cx: <DiffTransformSummary as sum_tree::Summary>::Context<'_>,
1027    ) {
1028        self.output_dimension.add_summary(summary, cx);
1029        self.excerpt_dimension.add_summary(summary, cx);
1030    }
1031}
1032
1033#[derive(Clone)]
1034struct MultiBufferCursor<'a, MBD, BD> {
1035    excerpts: Cursor<'a, 'static, Excerpt, ExcerptDimension<MBD>>,
1036    diff_transforms: Cursor<'a, 'static, DiffTransform, DiffTransforms<MBD>>,
1037    diffs: &'a TreeMap<BufferId, DiffStateSnapshot>,
1038    cached_region: OnceCell<Option<MultiBufferRegion<'a, MBD, BD>>>,
1039}
1040
1041#[derive(Clone)]
1042struct MultiBufferRegion<'a, MBD, BD> {
1043    buffer: &'a BufferSnapshot,
1044    is_main_buffer: bool,
1045    diff_hunk_status: Option<DiffHunkStatus>,
1046    excerpt: &'a Excerpt,
1047    buffer_range: Range<BD>,
1048    range: Range<MBD>,
1049    has_trailing_newline: bool,
1050}
1051
1052struct ExcerptChunks<'a> {
1053    content_chunks: BufferChunks<'a>,
1054    has_footer: bool,
1055}
1056
1057#[derive(Debug)]
1058struct BufferEdit {
1059    range: Range<BufferOffset>,
1060    new_text: Arc<str>,
1061    is_insertion: bool,
1062    original_indent_column: Option<u32>,
1063}
1064
1065#[derive(Clone, Copy, Debug, PartialEq)]
1066enum DiffChangeKind {
1067    BufferEdited,
1068    DiffUpdated { base_changed: bool },
1069    ExpandOrCollapseHunks { expand: bool },
1070}
1071
1072#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
1073pub enum ExpandExcerptDirection {
1074    Up,
1075    Down,
1076    UpAndDown,
1077}
1078
1079impl ExpandExcerptDirection {
1080    pub fn should_expand_up(&self) -> bool {
1081        match self {
1082            ExpandExcerptDirection::Up => true,
1083            ExpandExcerptDirection::Down => false,
1084            ExpandExcerptDirection::UpAndDown => true,
1085        }
1086    }
1087
1088    pub fn should_expand_down(&self) -> bool {
1089        match self {
1090            ExpandExcerptDirection::Up => false,
1091            ExpandExcerptDirection::Down => true,
1092            ExpandExcerptDirection::UpAndDown => true,
1093        }
1094    }
1095}
1096
1097#[derive(Clone, Debug, PartialEq)]
1098pub struct IndentGuide {
1099    pub buffer_id: BufferId,
1100    pub start_row: MultiBufferRow,
1101    pub end_row: MultiBufferRow,
1102    pub depth: u32,
1103    pub tab_size: u32,
1104    pub settings: IndentGuideSettings,
1105}
1106
1107impl IndentGuide {
1108    pub fn indent_level(&self) -> u32 {
1109        self.depth * self.tab_size
1110    }
1111}
1112
1113impl MultiBuffer {
1114    pub fn new(capability: Capability) -> Self {
1115        Self::new_(
1116            capability,
1117            MultiBufferSnapshot {
1118                show_headers: true,
1119                show_deleted_hunks: true,
1120                ..MultiBufferSnapshot::default()
1121            },
1122        )
1123    }
1124
1125    pub fn without_headers(capability: Capability) -> Self {
1126        Self::new_(
1127            capability,
1128            MultiBufferSnapshot {
1129                show_deleted_hunks: true,
1130                ..MultiBufferSnapshot::default()
1131            },
1132        )
1133    }
1134
1135    pub fn singleton(buffer: Entity<Buffer>, cx: &mut Context<Self>) -> Self {
1136        let mut this = Self::new_(
1137            buffer.read(cx).capability(),
1138            MultiBufferSnapshot {
1139                singleton: true,
1140                show_deleted_hunks: true,
1141                ..MultiBufferSnapshot::default()
1142            },
1143        );
1144        this.singleton = true;
1145        this.set_excerpts_for_path(
1146            PathKey::sorted(0),
1147            buffer.clone(),
1148            [Point::zero()..buffer.read(cx).max_point()],
1149            0,
1150            cx,
1151        );
1152        this
1153    }
1154
1155    #[inline]
1156    pub fn new_(capability: Capability, snapshot: MultiBufferSnapshot) -> Self {
1157        Self {
1158            snapshot: RefCell::new(snapshot),
1159            buffers: Default::default(),
1160            diffs: HashMap::default(),
1161            subscriptions: Topic::default(),
1162            singleton: false,
1163            capability,
1164            title: None,
1165            buffer_changed_since_sync: Default::default(),
1166            history: History::default(),
1167        }
1168    }
1169
1170    pub fn clone(&self, new_cx: &mut Context<Self>) -> Self {
1171        let mut buffers = BTreeMap::default();
1172        let buffer_changed_since_sync = Rc::new(Cell::new(false));
1173        for (buffer_id, buffer_state) in self.buffers.iter() {
1174            buffer_state.buffer.update(new_cx, |buffer, _| {
1175                buffer.record_changes(Rc::downgrade(&buffer_changed_since_sync));
1176            });
1177            buffers.insert(
1178                *buffer_id,
1179                BufferState {
1180                    buffer: buffer_state.buffer.clone(),
1181                    path_key: buffer_state.path_key.clone(),
1182                    last_version: buffer_state.last_version.clone(),
1183                    last_non_text_state_update_count: buffer_state
1184                        .last_non_text_state_update_count
1185                        .clone(),
1186                    _subscriptions: [
1187                        new_cx.observe(&buffer_state.buffer, |_, _, cx| cx.notify()),
1188                        new_cx.subscribe(&buffer_state.buffer, Self::on_buffer_event),
1189                    ],
1190                },
1191            );
1192        }
1193        let mut diff_bases = HashMap::default();
1194        for (buffer_id, diff) in self.diffs.iter() {
1195            diff_bases.insert(*buffer_id, DiffState::new(diff.diff.clone(), new_cx));
1196        }
1197        Self {
1198            snapshot: RefCell::new(self.snapshot.borrow().clone()),
1199            buffers,
1200            diffs: diff_bases,
1201            subscriptions: Default::default(),
1202            singleton: self.singleton,
1203            capability: self.capability,
1204            history: self.history.clone(),
1205            title: self.title.clone(),
1206            buffer_changed_since_sync,
1207        }
1208    }
1209
1210    pub fn set_group_interval(&mut self, group_interval: Duration) {
1211        self.history.set_group_interval(group_interval);
1212    }
1213
1214    pub fn with_title(mut self, title: String) -> Self {
1215        self.title = Some(title);
1216        self
1217    }
1218
1219    pub fn read_only(&self) -> bool {
1220        !self.capability.editable()
1221    }
1222
1223    pub fn capability(&self) -> Capability {
1224        self.capability
1225    }
1226
1227    /// Returns an up-to-date snapshot of the MultiBuffer.
1228    #[ztracing::instrument(skip_all)]
1229    pub fn snapshot(&self, cx: &App) -> MultiBufferSnapshot {
1230        self.sync(cx);
1231        self.snapshot.borrow().clone()
1232    }
1233
1234    pub fn read(&self, cx: &App) -> Ref<'_, MultiBufferSnapshot> {
1235        self.sync(cx);
1236        self.snapshot.borrow()
1237    }
1238
1239    pub fn as_singleton(&self) -> Option<Entity<Buffer>> {
1240        if self.singleton {
1241            Some(self.buffers.values().next().unwrap().buffer.clone())
1242        } else {
1243            None
1244        }
1245    }
1246
1247    pub fn is_singleton(&self) -> bool {
1248        self.singleton
1249    }
1250
1251    pub fn subscribe(&mut self) -> Subscription<MultiBufferOffset> {
1252        self.subscriptions.subscribe()
1253    }
1254
1255    pub fn is_dirty(&self, cx: &App) -> bool {
1256        self.read(cx).is_dirty()
1257    }
1258
1259    pub fn has_deleted_file(&self, cx: &App) -> bool {
1260        self.read(cx).has_deleted_file()
1261    }
1262
1263    pub fn has_conflict(&self, cx: &App) -> bool {
1264        self.read(cx).has_conflict()
1265    }
1266
1267    // The `is_empty` signature doesn't match what clippy expects
1268    #[allow(clippy::len_without_is_empty)]
1269    pub fn len(&self, cx: &App) -> MultiBufferOffset {
1270        self.read(cx).len()
1271    }
1272
1273    pub fn is_empty(&self) -> bool {
1274        self.buffers.is_empty()
1275    }
1276
1277    pub fn edit<I, S, T>(
1278        &mut self,
1279        edits: I,
1280        autoindent_mode: Option<AutoindentMode>,
1281        cx: &mut Context<Self>,
1282    ) where
1283        I: IntoIterator<Item = (Range<S>, T)>,
1284        S: ToOffset,
1285        T: Into<Arc<str>>,
1286    {
1287        self.edit_internal(edits, autoindent_mode, true, cx);
1288    }
1289
1290    pub fn edit_non_coalesce<I, S, T>(
1291        &mut self,
1292        edits: I,
1293        autoindent_mode: Option<AutoindentMode>,
1294        cx: &mut Context<Self>,
1295    ) where
1296        I: IntoIterator<Item = (Range<S>, T)>,
1297        S: ToOffset,
1298        T: Into<Arc<str>>,
1299    {
1300        self.edit_internal(edits, autoindent_mode, false, cx);
1301    }
1302
1303    fn edit_internal<I, S, T>(
1304        &mut self,
1305        edits: I,
1306        autoindent_mode: Option<AutoindentMode>,
1307        coalesce_adjacent: bool,
1308        cx: &mut Context<Self>,
1309    ) where
1310        I: IntoIterator<Item = (Range<S>, T)>,
1311        S: ToOffset,
1312        T: Into<Arc<str>>,
1313    {
1314        if self.read_only() || self.buffers.is_empty() {
1315            return;
1316        }
1317        self.sync_mut(cx);
1318        let edits = edits
1319            .into_iter()
1320            .map(|(range, new_text)| {
1321                let mut range = range.start.to_offset(self.snapshot.get_mut())
1322                    ..range.end.to_offset(self.snapshot.get_mut());
1323                if range.start > range.end {
1324                    mem::swap(&mut range.start, &mut range.end);
1325                }
1326                (range, new_text.into())
1327            })
1328            .collect::<Vec<_>>();
1329
1330        return edit_internal(self, edits, autoindent_mode, coalesce_adjacent, cx);
1331
1332        // Non-generic part of edit, hoisted out to avoid blowing up LLVM IR.
1333        fn edit_internal(
1334            this: &mut MultiBuffer,
1335            edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1336            mut autoindent_mode: Option<AutoindentMode>,
1337            coalesce_adjacent: bool,
1338            cx: &mut Context<MultiBuffer>,
1339        ) {
1340            let original_indent_columns = match &mut autoindent_mode {
1341                Some(AutoindentMode::Block {
1342                    original_indent_columns,
1343                }) => mem::take(original_indent_columns),
1344                _ => Default::default(),
1345            };
1346
1347            let buffer_edits = MultiBuffer::convert_edits_to_buffer_edits(
1348                edits,
1349                this.snapshot.get_mut(),
1350                &original_indent_columns,
1351            );
1352
1353            let mut buffer_ids = Vec::with_capacity(buffer_edits.len());
1354            for (buffer_id, mut edits) in buffer_edits {
1355                buffer_ids.push(buffer_id);
1356                edits.sort_by_key(|edit| edit.range.start);
1357                this.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1358                    let mut edits = edits.into_iter().peekable();
1359                    let mut insertions = Vec::new();
1360                    let mut original_indent_columns = Vec::new();
1361                    let mut deletions = Vec::new();
1362                    let empty_str: Arc<str> = Arc::default();
1363                    while let Some(BufferEdit {
1364                        mut range,
1365                        mut new_text,
1366                        mut is_insertion,
1367                        original_indent_column,
1368                    }) = edits.next()
1369                    {
1370                        while let Some(BufferEdit {
1371                            range: next_range,
1372                            is_insertion: next_is_insertion,
1373                            new_text: next_new_text,
1374                            ..
1375                        }) = edits.peek()
1376                        {
1377                            let should_coalesce = if coalesce_adjacent {
1378                                range.end >= next_range.start
1379                            } else {
1380                                range.end > next_range.start
1381                            };
1382
1383                            if should_coalesce {
1384                                range.end = cmp::max(next_range.end, range.end);
1385                                is_insertion |= *next_is_insertion;
1386                                new_text = format!("{new_text}{next_new_text}").into();
1387                                edits.next();
1388                            } else {
1389                                break;
1390                            }
1391                        }
1392
1393                        if is_insertion {
1394                            original_indent_columns.push(original_indent_column);
1395                            insertions.push((
1396                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
1397                                new_text.clone(),
1398                            ));
1399                        } else if !range.is_empty() {
1400                            deletions.push((
1401                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
1402                                empty_str.clone(),
1403                            ));
1404                        }
1405                    }
1406
1407                    let deletion_autoindent_mode =
1408                        if let Some(AutoindentMode::Block { .. }) = autoindent_mode {
1409                            Some(AutoindentMode::Block {
1410                                original_indent_columns: Default::default(),
1411                            })
1412                        } else {
1413                            autoindent_mode.clone()
1414                        };
1415                    let insertion_autoindent_mode =
1416                        if let Some(AutoindentMode::Block { .. }) = autoindent_mode {
1417                            Some(AutoindentMode::Block {
1418                                original_indent_columns,
1419                            })
1420                        } else {
1421                            autoindent_mode.clone()
1422                        };
1423
1424                    if coalesce_adjacent {
1425                        buffer.edit(deletions, deletion_autoindent_mode, cx);
1426                        buffer.edit(insertions, insertion_autoindent_mode, cx);
1427                    } else {
1428                        buffer.edit_non_coalesce(deletions, deletion_autoindent_mode, cx);
1429                        buffer.edit_non_coalesce(insertions, insertion_autoindent_mode, cx);
1430                    }
1431                })
1432            }
1433
1434            cx.emit(Event::BuffersEdited { buffer_ids });
1435        }
1436    }
1437
1438    fn convert_edits_to_buffer_edits(
1439        edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1440        snapshot: &MultiBufferSnapshot,
1441        original_indent_columns: &[Option<u32>],
1442    ) -> HashMap<BufferId, Vec<BufferEdit>> {
1443        let mut buffer_edits: HashMap<BufferId, Vec<BufferEdit>> = Default::default();
1444        let mut cursor = snapshot.cursor::<MultiBufferOffset, BufferOffset>();
1445        for (ix, (range, new_text)) in edits.into_iter().enumerate() {
1446            let original_indent_column = original_indent_columns.get(ix).copied().flatten();
1447
1448            cursor.seek(&range.start);
1449            let mut start_region = cursor.region().expect("start offset out of bounds");
1450            if !start_region.is_main_buffer {
1451                cursor.next();
1452                if let Some(region) = cursor.region() {
1453                    start_region = region;
1454                } else {
1455                    continue;
1456                }
1457            }
1458
1459            if range.end < start_region.range.start {
1460                continue;
1461            }
1462
1463            let start_region = start_region.clone();
1464            if range.end > start_region.range.end {
1465                cursor.seek_forward(&range.end);
1466            }
1467            let mut end_region = cursor.region().expect("end offset out of bounds");
1468            if !end_region.is_main_buffer {
1469                cursor.prev();
1470                if let Some(region) = cursor.region() {
1471                    end_region = region;
1472                } else {
1473                    continue;
1474                }
1475            }
1476
1477            if range.start > end_region.range.end {
1478                continue;
1479            }
1480
1481            let start_overshoot = range.start.saturating_sub(start_region.range.start);
1482            let end_overshoot = range.end.saturating_sub(end_region.range.start);
1483            let buffer_start = (start_region.buffer_range.start + start_overshoot)
1484                .min(start_region.buffer_range.end);
1485            let buffer_end =
1486                (end_region.buffer_range.start + end_overshoot).min(end_region.buffer_range.end);
1487
1488            if start_region.excerpt == end_region.excerpt {
1489                if start_region.buffer.capability == Capability::ReadWrite
1490                    && start_region.is_main_buffer
1491                {
1492                    buffer_edits
1493                        .entry(start_region.buffer.remote_id())
1494                        .or_default()
1495                        .push(BufferEdit {
1496                            range: buffer_start..buffer_end,
1497                            new_text,
1498                            is_insertion: true,
1499                            original_indent_column,
1500                        });
1501                }
1502            } else {
1503                let start_excerpt_range = buffer_start..start_region.buffer_range.end;
1504                let end_excerpt_range = end_region.buffer_range.start..buffer_end;
1505                if start_region.buffer.capability == Capability::ReadWrite
1506                    && start_region.is_main_buffer
1507                {
1508                    buffer_edits
1509                        .entry(start_region.buffer.remote_id())
1510                        .or_default()
1511                        .push(BufferEdit {
1512                            range: start_excerpt_range,
1513                            new_text: new_text.clone(),
1514                            is_insertion: true,
1515                            original_indent_column,
1516                        });
1517                }
1518                if end_region.buffer.capability == Capability::ReadWrite
1519                    && end_region.is_main_buffer
1520                {
1521                    buffer_edits
1522                        .entry(end_region.buffer.remote_id())
1523                        .or_default()
1524                        .push(BufferEdit {
1525                            range: end_excerpt_range,
1526                            new_text: new_text.clone(),
1527                            is_insertion: false,
1528                            original_indent_column,
1529                        });
1530                }
1531                let end_region_excerpt = end_region.excerpt.clone();
1532
1533                cursor.seek(&range.start);
1534                cursor.next_excerpt();
1535                while let Some(region) = cursor.region() {
1536                    if region.excerpt == &end_region_excerpt {
1537                        break;
1538                    }
1539                    if region.buffer.capability == Capability::ReadWrite && region.is_main_buffer {
1540                        buffer_edits
1541                            .entry(region.buffer.remote_id())
1542                            .or_default()
1543                            .push(BufferEdit {
1544                                range: region.buffer_range.clone(),
1545                                new_text: new_text.clone(),
1546                                is_insertion: false,
1547                                original_indent_column,
1548                            });
1549                    }
1550                    cursor.next_excerpt();
1551                }
1552            }
1553        }
1554        buffer_edits
1555    }
1556
1557    pub fn autoindent_ranges<I, S>(&mut self, ranges: I, cx: &mut Context<Self>)
1558    where
1559        I: IntoIterator<Item = Range<S>>,
1560        S: ToOffset,
1561    {
1562        if self.read_only() || self.buffers.is_empty() {
1563            return;
1564        }
1565        self.sync_mut(cx);
1566        let empty = Arc::<str>::from("");
1567        let edits = ranges
1568            .into_iter()
1569            .map(|range| {
1570                let mut range = range.start.to_offset(self.snapshot.get_mut())
1571                    ..range.end.to_offset(&self.snapshot.get_mut());
1572                if range.start > range.end {
1573                    mem::swap(&mut range.start, &mut range.end);
1574                }
1575                (range, empty.clone())
1576            })
1577            .collect::<Vec<_>>();
1578
1579        return autoindent_ranges_internal(self, edits, cx);
1580
1581        fn autoindent_ranges_internal(
1582            this: &mut MultiBuffer,
1583            edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1584            cx: &mut Context<MultiBuffer>,
1585        ) {
1586            let buffer_edits =
1587                MultiBuffer::convert_edits_to_buffer_edits(edits, this.snapshot.get_mut(), &[]);
1588
1589            let mut buffer_ids = Vec::new();
1590            for (buffer_id, mut edits) in buffer_edits {
1591                buffer_ids.push(buffer_id);
1592                edits.sort_unstable_by_key(|edit| edit.range.start);
1593
1594                let mut ranges: Vec<Range<BufferOffset>> = Vec::new();
1595                for edit in edits {
1596                    if let Some(last_range) = ranges.last_mut()
1597                        && edit.range.start <= last_range.end
1598                    {
1599                        last_range.end = last_range.end.max(edit.range.end);
1600                        continue;
1601                    }
1602                    ranges.push(edit.range);
1603                }
1604
1605                this.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1606                    buffer.autoindent_ranges(ranges, cx);
1607                })
1608            }
1609
1610            cx.emit(Event::BuffersEdited { buffer_ids });
1611        }
1612    }
1613
1614    pub fn set_active_selections(
1615        &self,
1616        selections: &[Selection<Anchor>],
1617        line_mode: bool,
1618        cursor_shape: CursorShape,
1619        cx: &mut Context<Self>,
1620    ) {
1621        let mut selections_by_buffer: HashMap<BufferId, Vec<Selection<text::Anchor>>> =
1622            Default::default();
1623        let snapshot = self.read(cx);
1624        let mut cursor = snapshot.excerpts.cursor::<ExcerptSummary>(());
1625        for selection in selections {
1626            let Some(start) = snapshot.anchor_seek_target(selection.start) else {
1627                continue;
1628            };
1629            let Some(end) = snapshot.anchor_seek_target(selection.end) else {
1630                continue;
1631            };
1632
1633            cursor.seek(&start, Bias::Left);
1634            while let Some(excerpt) = cursor.item()
1635                && sum_tree::SeekTarget::cmp(&end, &cursor.position, ()).is_gt()
1636            {
1637                let start = text::Anchor::max(
1638                    &excerpt.range.context.start,
1639                    &selection.start.text_anchor().unwrap_or(text::Anchor::MIN),
1640                    &excerpt.buffer,
1641                )
1642                .clone();
1643                let end = text::Anchor::min(
1644                    &excerpt.range.context.end,
1645                    &selection.end.text_anchor().unwrap_or(text::Anchor::MAX),
1646                    &excerpt.buffer,
1647                )
1648                .clone();
1649                selections_by_buffer
1650                    .entry(excerpt.buffer.remote_id())
1651                    .or_default()
1652                    .push(Selection {
1653                        id: selection.id,
1654                        start,
1655                        end,
1656                        reversed: selection.reversed,
1657                        goal: selection.goal,
1658                    });
1659
1660                cursor.next();
1661            }
1662        }
1663
1664        for (buffer_id, buffer_state) in self.buffers.iter() {
1665            if !selections_by_buffer.contains_key(buffer_id) {
1666                buffer_state
1667                    .buffer
1668                    .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
1669            }
1670        }
1671
1672        for (buffer_id, selections) in selections_by_buffer {
1673            self.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1674                buffer.set_active_selections(selections.into(), line_mode, cursor_shape, cx);
1675            });
1676        }
1677    }
1678
1679    pub fn remove_active_selections(&self, cx: &mut Context<Self>) {
1680        for buffer in self.buffers.values() {
1681            buffer
1682                .buffer
1683                .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
1684        }
1685    }
1686
1687    #[instrument(skip_all)]
1688    fn merge_excerpt_ranges<'a>(
1689        expanded_ranges: impl IntoIterator<Item = &'a ExcerptRange<Point>> + 'a,
1690    ) -> (Vec<ExcerptRange<Point>>, Vec<usize>) {
1691        let mut merged_ranges: Vec<ExcerptRange<Point>> = Vec::new();
1692        let mut counts: Vec<usize> = Vec::new();
1693        for range in expanded_ranges {
1694            if let Some(last_range) = merged_ranges.last_mut() {
1695                assert!(
1696                    last_range.context.start <= range.context.start,
1697                    "ranges must be sorted: {last_range:?} <= {range:?}"
1698                );
1699                if last_range.context.end >= range.context.start
1700                    || last_range.context.end.row + 1 == range.context.start.row
1701                {
1702                    last_range.context.end = range.context.end.max(last_range.context.end);
1703                    *counts.last_mut().unwrap() += 1;
1704                    continue;
1705                }
1706            }
1707            merged_ranges.push(range.clone());
1708            counts.push(1);
1709        }
1710        (merged_ranges, counts)
1711    }
1712
1713    pub fn clear(&mut self, cx: &mut Context<Self>) {
1714        self.sync_mut(cx);
1715        let removed_buffer_ids = std::mem::take(&mut self.buffers).into_keys().collect();
1716        let MultiBufferSnapshot {
1717            excerpts,
1718            diffs: _,
1719            diff_transforms: _,
1720            non_text_state_update_count: _,
1721            edit_count: _,
1722            is_dirty,
1723            has_deleted_file,
1724            has_conflict,
1725            has_inverted_diff,
1726            singleton: _,
1727            trailing_excerpt_update_count,
1728            all_diff_hunks_expanded: _,
1729            show_deleted_hunks: _,
1730            use_extended_diff_range: _,
1731            show_headers: _,
1732            path_keys: _,
1733        } = self.snapshot.get_mut();
1734        let start = ExcerptDimension(MultiBufferOffset::ZERO);
1735        let prev_len = ExcerptDimension(excerpts.summary().text.len);
1736        *excerpts = Default::default();
1737        *trailing_excerpt_update_count += 1;
1738        *is_dirty = false;
1739        *has_deleted_file = false;
1740        *has_conflict = false;
1741        *has_inverted_diff = false;
1742
1743        let edits = Self::sync_diff_transforms(
1744            self.snapshot.get_mut(),
1745            vec![Edit {
1746                old: start..prev_len,
1747                new: start..start,
1748            }],
1749            DiffChangeKind::BufferEdited,
1750        );
1751        if !edits.is_empty() {
1752            self.subscriptions.publish(edits);
1753        }
1754        cx.emit(Event::Edited {
1755            edited_buffer: None,
1756        });
1757        cx.emit(Event::BuffersRemoved { removed_buffer_ids });
1758        cx.notify();
1759    }
1760
1761    #[ztracing::instrument(skip_all)]
1762    pub fn excerpts_for_buffer(
1763        &self,
1764        buffer_id: BufferId,
1765        cx: &App,
1766    ) -> Vec<ExcerptRange<text::Anchor>> {
1767        let mut excerpts = Vec::new();
1768        let snapshot = self.read(cx);
1769        let Some(path_key) = snapshot.path_keys.get(&buffer_id).cloned() else {
1770            return excerpts;
1771        };
1772
1773        let mut cursor = snapshot.excerpts.cursor::<PathKey>(());
1774        cursor.seek_forward(&path_key, Bias::Left);
1775
1776        while let Some(item) = cursor.item()
1777            && item.path_key == path_key
1778        {
1779            excerpts.push(item.range.clone());
1780            cursor.next()
1781        }
1782        excerpts
1783    }
1784
1785    pub fn excerpt_ranges_for_buffer(&self, buffer_id: BufferId, cx: &App) -> Vec<Range<Point>> {
1786        let snapshot = self.read(cx);
1787        let mut excerpts = snapshot
1788            .excerpts
1789            .cursor::<Dimensions<PathKey, ExcerptPoint>>(());
1790        let mut diff_transforms = snapshot
1791            .diff_transforms
1792            .cursor::<Dimensions<ExcerptPoint, OutputDimension<Point>>>(());
1793        diff_transforms.next();
1794        let mut result = Vec::new();
1795        let Some(path_key) = snapshot.path_keys.get(&buffer_id) else {
1796            return result;
1797        };
1798
1799        while let Some(excerpt) = excerpts.item()
1800            && &excerpt.path_key == path_key
1801        {
1802            let excerpt_start = excerpts.start().1;
1803            let excerpt_end = excerpt_start + excerpt.text_summary.lines;
1804
1805            diff_transforms.seek_forward(&excerpt_start, Bias::Left);
1806            let overshoot = excerpt_start - diff_transforms.start().0;
1807            let start = diff_transforms.start().1 + overshoot;
1808
1809            diff_transforms.seek_forward(&excerpt_end, Bias::Right);
1810            let overshoot = excerpt_end - diff_transforms.start().0;
1811            let end = diff_transforms.start().1 + overshoot;
1812
1813            result.push(start.0..end.0);
1814            excerpts.next()
1815        }
1816        result
1817    }
1818
1819    // todo!() this seems bogus
1820    pub fn excerpt_buffer_ids(&self) -> Vec<BufferId> {
1821        self.snapshot
1822            .borrow()
1823            .excerpts
1824            .iter()
1825            .map(|entry| entry.buffer.remote_id())
1826            .collect()
1827    }
1828
1829    pub fn excerpt_containing(&self, position: impl ToOffset, cx: &App) -> Option<ExcerptInfo> {
1830        let snapshot = self.read(cx);
1831        let offset = position.to_offset(&snapshot);
1832
1833        let mut cursor = snapshot.cursor::<MultiBufferOffset, BufferOffset>();
1834        cursor.seek(&offset);
1835        let excerpt = cursor.excerpt().or(snapshot.excerpts.last())?;
1836        Some(ExcerptInfo {
1837            path_key: excerpt.path_key.clone(),
1838            buffer_id: excerpt.buffer.remote_id(),
1839            range: excerpt.range.clone(),
1840        })
1841    }
1842
1843    pub fn buffer_for_anchor(&self, anchor: Anchor, cx: &App) -> Option<Entity<Buffer>> {
1844        let buffer_id = match anchor {
1845            Anchor::Min => self.snapshot(cx).excerpts.first()?.buffer.remote_id(),
1846            Anchor::Max => self.snapshot(cx).excerpts.last()?.buffer.remote_id(),
1847            Anchor::Text { buffer_id, .. } => buffer_id,
1848        };
1849        self.buffer(buffer_id)
1850    }
1851
1852    // If point is at the end of the buffer, the last excerpt is returned
1853    pub fn point_to_buffer_offset<T: ToOffset>(
1854        &self,
1855        point: T,
1856        cx: &App,
1857    ) -> Option<(Entity<Buffer>, BufferOffset)> {
1858        let snapshot = self.read(cx);
1859        let (buffer, offset) = snapshot.point_to_buffer_offset(point)?;
1860        Some((
1861            self.buffers.get(&buffer.remote_id())?.buffer.clone(),
1862            offset,
1863        ))
1864    }
1865
1866    // If point is at the end of the buffer, the last excerpt is returned
1867    pub fn point_to_buffer_point<T: ToPoint>(
1868        &self,
1869        point: T,
1870        cx: &App,
1871    ) -> Option<(Entity<Buffer>, Point)> {
1872        let snapshot = self.read(cx);
1873        let (buffer, point) = snapshot.point_to_buffer_point(point.to_point(&snapshot))?;
1874        Some((self.buffers.get(&buffer.remote_id())?.buffer.clone(), point))
1875    }
1876
1877    pub fn buffer_point_to_anchor(
1878        &self,
1879        // todo(lw): We shouldn't need this?
1880        buffer: &Entity<Buffer>,
1881        point: Point,
1882        cx: &App,
1883    ) -> Option<Anchor> {
1884        let mut found = None;
1885        let snapshot = buffer.read(cx).snapshot();
1886        for range in self.excerpts_for_buffer(snapshot.remote_id(), cx) {
1887            let start = range.context.start.to_point(&snapshot);
1888            let end = range.context.end.to_point(&snapshot);
1889            if start <= point && point < end {
1890                found = Some(snapshot.clip_point(point, Bias::Left));
1891                break;
1892            }
1893            if point < start {
1894                found = Some(start);
1895            }
1896            if point > end {
1897                found = Some(end);
1898            }
1899        }
1900
1901        Some(Anchor::text(snapshot.anchor_after(found?)))
1902    }
1903
1904    pub fn buffer_anchor_to_anchor(
1905        &self,
1906        // todo(lw): We shouldn't need this?
1907        buffer: &Entity<Buffer>,
1908        anchor: text::Anchor,
1909        cx: &App,
1910    ) -> Option<Anchor> {
1911        let snapshot = buffer.read(cx).snapshot();
1912        for range in self.excerpts_for_buffer(snapshot.remote_id(), cx) {
1913            if range.contains(&anchor, &snapshot) {
1914                return Some(Anchor::text(anchor));
1915            }
1916        }
1917
1918        None
1919    }
1920
1921    pub fn wait_for_anchors<'a, Anchors: 'a + Iterator<Item = Anchor>>(
1922        &self,
1923        anchors: Anchors,
1924        cx: &mut Context<Self>,
1925    ) -> impl 'static + Future<Output = Result<()>> + use<Anchors> {
1926        let mut error = None;
1927        let mut futures = Vec::new();
1928        for anchor in anchors {
1929            if let Some(text_anchor) = anchor.text_anchor() {
1930                if let Some(buffer) = self.buffers.get(&text_anchor.buffer_id.unwrap()) {
1931                    buffer.buffer.update(cx, |buffer, _| {
1932                        futures.push(buffer.wait_for_anchors([text_anchor]))
1933                    });
1934                } else {
1935                    error = Some(anyhow!(
1936                        "buffer {:?} is not part of this multi-buffer",
1937                        text_anchor.buffer_id
1938                    ));
1939                    break;
1940                }
1941            }
1942        }
1943        async move {
1944            if let Some(error) = error {
1945                Err(error)?;
1946            }
1947            for future in futures {
1948                future.await?;
1949            }
1950            Ok(())
1951        }
1952    }
1953
1954    pub fn text_anchor_for_position<T: ToOffset>(
1955        &self,
1956        position: T,
1957        cx: &App,
1958    ) -> Option<(Entity<Buffer>, text::Anchor)> {
1959        let snapshot = self.read(cx);
1960        let anchor = snapshot.anchor_before(position).text_anchor()?;
1961        let buffer = self.buffers.get(&anchor.buffer_id.unwrap())?.buffer.clone();
1962        Some((buffer, anchor))
1963    }
1964
1965    fn on_buffer_event(
1966        &mut self,
1967        buffer: Entity<Buffer>,
1968        event: &language::BufferEvent,
1969        cx: &mut Context<Self>,
1970    ) {
1971        use language::BufferEvent;
1972        let buffer_id = buffer.read(cx).remote_id();
1973        cx.emit(match event {
1974            BufferEvent::Edited => Event::Edited {
1975                edited_buffer: Some(buffer),
1976            },
1977            BufferEvent::DirtyChanged => Event::DirtyChanged,
1978            BufferEvent::Saved => Event::Saved,
1979            BufferEvent::FileHandleChanged => Event::FileHandleChanged,
1980            BufferEvent::Reloaded => Event::Reloaded,
1981            BufferEvent::LanguageChanged(has_language) => {
1982                Event::LanguageChanged(buffer_id, *has_language)
1983            }
1984            BufferEvent::Reparsed => Event::Reparsed(buffer_id),
1985            BufferEvent::DiagnosticsUpdated => Event::DiagnosticsUpdated,
1986            BufferEvent::CapabilityChanged => {
1987                self.capability = buffer.read(cx).capability();
1988                return;
1989            }
1990            BufferEvent::Operation { .. } | BufferEvent::ReloadNeeded => return,
1991        });
1992    }
1993
1994    fn buffer_diff_language_changed(&mut self, diff: Entity<BufferDiff>, cx: &mut Context<Self>) {
1995        let diff = diff.read(cx);
1996        let buffer_id = diff.buffer_id;
1997        let diff = DiffStateSnapshot {
1998            diff: diff.snapshot(cx),
1999            main_buffer: None,
2000        };
2001        self.snapshot.get_mut().diffs.insert(buffer_id, diff);
2002    }
2003
2004    fn inverted_buffer_diff_language_changed(
2005        &mut self,
2006        diff: Entity<BufferDiff>,
2007        main_buffer: Entity<language::Buffer>,
2008        cx: &mut Context<Self>,
2009    ) {
2010        let base_text_buffer_id = diff.read(cx).base_text_buffer().read(cx).remote_id();
2011        let main_buffer_snapshot = main_buffer.read(cx).snapshot();
2012        let diff = diff.read(cx);
2013        let diff = DiffStateSnapshot {
2014            diff: diff.snapshot(cx),
2015            main_buffer: Some(main_buffer_snapshot),
2016        };
2017        self.snapshot
2018            .get_mut()
2019            .diffs
2020            .insert(base_text_buffer_id, diff);
2021    }
2022
2023    fn buffer_diff_changed(
2024        &mut self,
2025        diff: Entity<BufferDiff>,
2026        range: Range<text::Anchor>,
2027        cx: &mut Context<Self>,
2028    ) {
2029        self.sync_mut(cx);
2030
2031        let diff = diff.read(cx);
2032        let buffer_id = diff.buffer_id;
2033
2034        let Some(buffer_state) = self.buffers.get(&buffer_id) else {
2035            return;
2036        };
2037        let new_diff = DiffStateSnapshot {
2038            diff: diff.snapshot(cx),
2039            main_buffer: None,
2040        };
2041        let mut snapshot = self.snapshot.get_mut();
2042        let base_text_changed = snapshot
2043            .diffs
2044            .get(&buffer_id)
2045            .is_none_or(|old_diff| !new_diff.base_texts_definitely_eq(old_diff));
2046        snapshot.diffs.insert_or_replace(buffer_id, new_diff);
2047
2048        let buffer = buffer_state.buffer.read(cx);
2049        let diff_change_range = range.to_offset(buffer);
2050
2051        let excerpt_edits = snapshot.excerpt_edits_for_diff_change(buffer_state, diff_change_range);
2052        let edits = Self::sync_diff_transforms(
2053            &mut snapshot,
2054            excerpt_edits,
2055            DiffChangeKind::DiffUpdated {
2056                base_changed: base_text_changed,
2057            },
2058        );
2059        if !edits.is_empty() {
2060            self.subscriptions.publish(edits);
2061        }
2062        cx.emit(Event::Edited {
2063            edited_buffer: None,
2064        });
2065    }
2066
2067    fn inverted_buffer_diff_changed(
2068        &mut self,
2069        diff: Entity<BufferDiff>,
2070        main_buffer: Entity<language::Buffer>,
2071        diff_change_range: Option<Range<usize>>,
2072        cx: &mut Context<Self>,
2073    ) {
2074        self.sync_mut(cx);
2075
2076        let base_text_buffer_id = diff.read(cx).base_text_buffer().read(cx).remote_id();
2077        let Some(buffer_state) = self.buffers.get(&base_text_buffer_id) else {
2078            return;
2079        };
2080
2081        let main_buffer_snapshot = main_buffer.read(cx).snapshot();
2082        let diff = diff.read(cx);
2083        let new_diff = DiffStateSnapshot {
2084            diff: diff.snapshot(cx),
2085            main_buffer: Some(main_buffer_snapshot),
2086        };
2087        let mut snapshot = self.snapshot.get_mut();
2088        snapshot
2089            .diffs
2090            .insert_or_replace(base_text_buffer_id, new_diff);
2091
2092        let Some(diff_change_range) = diff_change_range else {
2093            return;
2094        };
2095
2096        let excerpt_edits = snapshot.excerpt_edits_for_diff_change(buffer_state, diff_change_range);
2097        let edits = Self::sync_diff_transforms(
2098            &mut snapshot,
2099            excerpt_edits,
2100            DiffChangeKind::DiffUpdated {
2101                // We don't read this field for inverted diffs.
2102                base_changed: false,
2103            },
2104        );
2105        if !edits.is_empty() {
2106            self.subscriptions.publish(edits);
2107        }
2108        cx.emit(Event::Edited {
2109            edited_buffer: None,
2110        });
2111    }
2112
2113    pub fn all_buffers_iter(&self) -> impl Iterator<Item = Entity<Buffer>> {
2114        self.buffers.values().map(|state| state.buffer.clone())
2115    }
2116
2117    pub fn all_buffers(&self) -> HashSet<Entity<Buffer>> {
2118        self.all_buffers_iter().collect()
2119    }
2120
2121    pub fn all_buffer_ids_iter(&self) -> impl Iterator<Item = BufferId> {
2122        self.buffers.keys().copied()
2123    }
2124
2125    pub fn all_buffer_ids(&self) -> Vec<BufferId> {
2126        self.all_buffer_ids_iter().collect()
2127    }
2128
2129    pub fn buffer(&self, buffer_id: BufferId) -> Option<Entity<Buffer>> {
2130        self.buffers
2131            .get(&buffer_id)
2132            .map(|state| state.buffer.clone())
2133    }
2134
2135    pub fn language_at<T: ToOffset>(&self, point: T, cx: &App) -> Option<Arc<Language>> {
2136        self.point_to_buffer_offset(point, cx)
2137            .and_then(|(buffer, offset)| buffer.read(cx).language_at(offset))
2138    }
2139
2140    pub fn language_settings<'a>(&'a self, cx: &'a App) -> Cow<'a, LanguageSettings> {
2141        let buffer_id = self
2142            .snapshot
2143            .borrow()
2144            .excerpts
2145            .first()
2146            .map(|excerpt| excerpt.buffer.remote_id());
2147        buffer_id
2148            .and_then(|buffer_id| self.buffer(buffer_id))
2149            .map(|buffer| {
2150                let buffer = buffer.read(cx);
2151                language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx)
2152            })
2153            .unwrap_or_else(move || self.language_settings_at(MultiBufferOffset::default(), cx))
2154    }
2155
2156    pub fn language_settings_at<'a, T: ToOffset>(
2157        &'a self,
2158        point: T,
2159        cx: &'a App,
2160    ) -> Cow<'a, LanguageSettings> {
2161        let mut language = None;
2162        let mut file = None;
2163        if let Some((buffer, offset)) = self.point_to_buffer_offset(point, cx) {
2164            let buffer = buffer.read(cx);
2165            language = buffer.language_at(offset);
2166            file = buffer.file();
2167        }
2168        language_settings(language.map(|l| l.name()), file, cx)
2169    }
2170
2171    pub fn for_each_buffer(&self, f: &mut dyn FnMut(&Entity<Buffer>)) {
2172        self.buffers.values().for_each(|state| f(&state.buffer))
2173    }
2174
2175    pub fn explicit_title(&self) -> Option<&str> {
2176        self.title.as_deref()
2177    }
2178
2179    pub fn title<'a>(&'a self, cx: &'a App) -> Cow<'a, str> {
2180        if let Some(title) = self.title.as_ref() {
2181            return title.into();
2182        }
2183
2184        if let Some(buffer) = self.as_singleton() {
2185            let buffer = buffer.read(cx);
2186
2187            if let Some(file) = buffer.file() {
2188                return file.file_name(cx).into();
2189            }
2190
2191            if let Some(title) = self.buffer_content_title(buffer) {
2192                return title;
2193            }
2194        };
2195
2196        "untitled".into()
2197    }
2198
2199    fn buffer_content_title(&self, buffer: &Buffer) -> Option<Cow<'_, str>> {
2200        let mut is_leading_whitespace = true;
2201        let mut count = 0;
2202        let mut prev_was_space = false;
2203        let mut title = String::new();
2204
2205        for ch in buffer.snapshot().chars() {
2206            if is_leading_whitespace && ch.is_whitespace() {
2207                continue;
2208            }
2209
2210            is_leading_whitespace = false;
2211
2212            if ch == '\n' || count >= 40 {
2213                break;
2214            }
2215
2216            if ch.is_whitespace() {
2217                if !prev_was_space {
2218                    title.push(' ');
2219                    count += 1;
2220                    prev_was_space = true;
2221                }
2222            } else {
2223                title.push(ch);
2224                count += 1;
2225                prev_was_space = false;
2226            }
2227        }
2228
2229        let title = title.trim_end().to_string();
2230
2231        if title.is_empty() {
2232            return None;
2233        }
2234
2235        Some(title.into())
2236    }
2237
2238    pub fn set_title(&mut self, title: String, cx: &mut Context<Self>) {
2239        self.title = Some(title);
2240        cx.notify();
2241    }
2242
2243    /// Preserve preview tabs containing this multibuffer until additional edits occur.
2244    pub fn refresh_preview(&self, cx: &mut Context<Self>) {
2245        for buffer_state in self.buffers.values() {
2246            buffer_state
2247                .buffer
2248                .update(cx, |buffer, _cx| buffer.refresh_preview());
2249        }
2250    }
2251
2252    /// Whether we should preserve the preview status of a tab containing this multi-buffer.
2253    pub fn preserve_preview(&self, cx: &App) -> bool {
2254        self.buffers
2255            .values()
2256            .all(|state| state.buffer.read(cx).preserve_preview())
2257    }
2258
2259    #[cfg(any(test, feature = "test-support"))]
2260    pub fn is_parsing(&self, cx: &App) -> bool {
2261        self.as_singleton().unwrap().read(cx).is_parsing()
2262    }
2263
2264    pub fn add_diff(&mut self, diff: Entity<BufferDiff>, cx: &mut Context<Self>) {
2265        let buffer_id = diff.read(cx).buffer_id;
2266
2267        if let Some(existing_diff) = self.diff_for(buffer_id)
2268            && diff.entity_id() == existing_diff.entity_id()
2269        {
2270            return;
2271        }
2272
2273        self.buffer_diff_changed(
2274            diff.clone(),
2275            text::Anchor::min_max_range_for_buffer(buffer_id),
2276            cx,
2277        );
2278        self.diffs.insert(buffer_id, DiffState::new(diff, cx));
2279    }
2280
2281    pub fn add_inverted_diff(
2282        &mut self,
2283        diff: Entity<BufferDiff>,
2284        main_buffer: Entity<language::Buffer>,
2285        cx: &mut Context<Self>,
2286    ) {
2287        let snapshot = diff.read(cx).base_text(cx);
2288        let base_text_buffer_id = snapshot.remote_id();
2289        let diff_change_range = 0..snapshot.len();
2290        self.snapshot.get_mut().has_inverted_diff = true;
2291        self.inverted_buffer_diff_changed(
2292            diff.clone(),
2293            main_buffer.clone(),
2294            Some(diff_change_range),
2295            cx,
2296        );
2297        self.diffs.insert(
2298            base_text_buffer_id,
2299            DiffState::new_inverted(diff, main_buffer, cx),
2300        );
2301    }
2302
2303    pub fn diff_for(&self, buffer_id: BufferId) -> Option<Entity<BufferDiff>> {
2304        self.diffs.get(&buffer_id).map(|state| state.diff.clone())
2305    }
2306
2307    pub fn expand_diff_hunks(&mut self, ranges: Vec<Range<Anchor>>, cx: &mut Context<Self>) {
2308        self.expand_or_collapse_diff_hunks(ranges, true, cx);
2309    }
2310
2311    pub fn collapse_diff_hunks(&mut self, ranges: Vec<Range<Anchor>>, cx: &mut Context<Self>) {
2312        self.expand_or_collapse_diff_hunks(ranges, false, cx);
2313    }
2314
2315    pub fn set_all_diff_hunks_expanded(&mut self, cx: &mut Context<Self>) {
2316        self.snapshot.get_mut().all_diff_hunks_expanded = true;
2317        self.expand_or_collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], true, cx);
2318    }
2319
2320    pub fn all_diff_hunks_expanded(&self) -> bool {
2321        self.snapshot.borrow().all_diff_hunks_expanded
2322    }
2323
2324    pub fn set_all_diff_hunks_collapsed(&mut self, cx: &mut Context<Self>) {
2325        self.snapshot.get_mut().all_diff_hunks_expanded = false;
2326        self.expand_or_collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], false, cx);
2327    }
2328
2329    pub fn set_show_deleted_hunks(&mut self, show: bool, cx: &mut Context<Self>) {
2330        self.snapshot.get_mut().show_deleted_hunks = show;
2331
2332        self.sync_mut(cx);
2333
2334        let old_len = self.snapshot.borrow().len();
2335
2336        let ranges = std::iter::once((Point::zero()..Point::MAX, ExcerptId::max()));
2337        let _ = self.expand_or_collapse_diff_hunks_inner(ranges, true, cx);
2338
2339        let new_len = self.snapshot.borrow().len();
2340
2341        self.subscriptions.publish(vec![Edit {
2342            old: MultiBufferOffset(0)..old_len,
2343            new: MultiBufferOffset(0)..new_len,
2344        }]);
2345
2346        cx.emit(Event::DiffHunksToggled);
2347        cx.emit(Event::Edited {
2348            edited_buffer: None,
2349        });
2350    }
2351
2352    pub fn set_use_extended_diff_range(&mut self, use_extended: bool, _cx: &mut Context<Self>) {
2353        self.snapshot.get_mut().use_extended_diff_range = use_extended;
2354    }
2355
2356    pub fn has_multiple_hunks(&self, cx: &App) -> bool {
2357        self.read(cx)
2358            .diff_hunks_in_range(Anchor::min()..Anchor::max())
2359            .nth(1)
2360            .is_some()
2361    }
2362
2363    pub fn single_hunk_is_expanded(&self, range: Range<Anchor>, cx: &App) -> bool {
2364        let snapshot = self.read(cx);
2365        let mut cursor = snapshot.diff_transforms.cursor::<MultiBufferOffset>(());
2366        let offset_range = range.to_offset(&snapshot);
2367        cursor.seek(&offset_range.start, Bias::Left);
2368        while let Some(item) = cursor.item() {
2369            if *cursor.start() >= offset_range.end && *cursor.start() > offset_range.start {
2370                break;
2371            }
2372            if item.hunk_info().is_some() {
2373                return true;
2374            }
2375            cursor.next();
2376        }
2377        false
2378    }
2379
2380    pub fn has_expanded_diff_hunks_in_ranges(&self, ranges: &[Range<Anchor>], cx: &App) -> bool {
2381        let snapshot = self.read(cx);
2382        let mut cursor = snapshot.diff_transforms.cursor::<MultiBufferOffset>(());
2383        for range in ranges {
2384            let range = range.to_point(&snapshot);
2385            let start = snapshot.point_to_offset(Point::new(range.start.row, 0));
2386            let end = (snapshot.point_to_offset(Point::new(range.end.row + 1, 0)) + 1usize)
2387                .min(snapshot.len());
2388            cursor.seek(&start, Bias::Right);
2389            while let Some(item) = cursor.item() {
2390                if *cursor.start() >= end {
2391                    break;
2392                }
2393                if item.hunk_info().is_some() {
2394                    return true;
2395                }
2396                cursor.next();
2397            }
2398        }
2399        false
2400    }
2401
2402    pub fn expand_or_collapse_diff_hunks_inner(
2403        &mut self,
2404        ranges: impl IntoIterator<Item = (Range<Point>, ExcerptId)>,
2405        expand: bool,
2406        cx: &mut Context<Self>,
2407    ) -> Vec<Edit<MultiBufferOffset>> {
2408        if self.snapshot.borrow().all_diff_hunks_expanded && !expand {
2409            return Vec::new();
2410        }
2411        self.sync_mut(cx);
2412        let mut snapshot = self.snapshot.get_mut();
2413        let mut excerpt_edits = Vec::new();
2414        let mut last_hunk_row = None;
2415        for (range, end_excerpt_id) in ranges {
2416            for diff_hunk in snapshot.diff_hunks_in_range(range) {
2417                if diff_hunk.excerpt_id.cmp(&end_excerpt_id, &snapshot).is_gt() {
2418                    continue;
2419                }
2420                if last_hunk_row.is_some_and(|row| row >= diff_hunk.row_range.start) {
2421                    continue;
2422                }
2423                let start = Anchor::text(diff_hunk.excerpt_id, diff_hunk.buffer_range.start);
2424                let end = Anchor::text(diff_hunk.excerpt_id, diff_hunk.buffer_range.end);
2425                let start = snapshot.excerpt_offset_for_anchor(&start);
2426                let end = snapshot.excerpt_offset_for_anchor(&end);
2427                last_hunk_row = Some(diff_hunk.row_range.start);
2428                excerpt_edits.push(text::Edit {
2429                    old: start..end,
2430                    new: start..end,
2431                });
2432            }
2433        }
2434
2435        Self::sync_diff_transforms(
2436            &mut snapshot,
2437            excerpt_edits,
2438            DiffChangeKind::ExpandOrCollapseHunks { expand },
2439        )
2440    }
2441
2442    pub fn expand_or_collapse_diff_hunks(
2443        &mut self,
2444        ranges: Vec<Range<Anchor>>,
2445        expand: bool,
2446        cx: &mut Context<Self>,
2447    ) {
2448        let snapshot = self.snapshot.borrow().clone();
2449        let ranges = ranges.iter().map(move |range| {
2450            let end_excerpt_id = range.end.excerpt_id;
2451            let range = range.to_point(&snapshot);
2452            let mut peek_end = range.end;
2453            if range.end.row < snapshot.max_row().0 {
2454                peek_end = Point::new(range.end.row + 1, 0);
2455            };
2456            (range.start..peek_end, end_excerpt_id)
2457        });
2458        let edits = self.expand_or_collapse_diff_hunks_inner(ranges, expand, cx);
2459        if !edits.is_empty() {
2460            self.subscriptions.publish(edits);
2461        }
2462        cx.emit(Event::DiffHunksToggled);
2463        cx.emit(Event::Edited {
2464            edited_buffer: None,
2465        });
2466    }
2467
2468    pub fn resize_excerpt(
2469        &mut self,
2470        id: ExcerptId,
2471        range: Range<text::Anchor>,
2472        cx: &mut Context<Self>,
2473    ) {
2474        self.sync_mut(cx);
2475
2476        let mut snapshot = self.snapshot.get_mut();
2477        let locator = snapshot.excerpt_locator_for_id(id);
2478        let mut new_excerpts = SumTree::default();
2479        let mut cursor = snapshot
2480            .excerpts
2481            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2482        let mut edits = Vec::<Edit<ExcerptOffset>>::new();
2483
2484        let prefix = cursor.slice(&Some(locator), Bias::Left);
2485        new_excerpts.append(prefix, ());
2486
2487        let mut excerpt = cursor.item().unwrap().clone();
2488        let old_text_len = excerpt.text_summary.len;
2489
2490        excerpt.range.context.start = range.start;
2491        excerpt.range.context.end = range.end;
2492        excerpt.max_buffer_row = range.end.to_point(&excerpt.buffer).row;
2493
2494        excerpt.text_summary = excerpt
2495            .buffer
2496            .text_summary_for_range(excerpt.range.context.clone());
2497
2498        let new_start_offset = ExcerptDimension(new_excerpts.summary().text.len);
2499        let old_start_offset = cursor.start().1;
2500        let new_text_len = excerpt.text_summary.len;
2501        let edit = Edit {
2502            old: old_start_offset..old_start_offset + old_text_len,
2503            new: new_start_offset..new_start_offset + new_text_len,
2504        };
2505
2506        if let Some(last_edit) = edits.last_mut() {
2507            if last_edit.old.end == edit.old.start {
2508                last_edit.old.end = edit.old.end;
2509                last_edit.new.end = edit.new.end;
2510            } else {
2511                edits.push(edit);
2512            }
2513        } else {
2514            edits.push(edit);
2515        }
2516
2517        new_excerpts.push(excerpt, ());
2518
2519        cursor.next();
2520
2521        new_excerpts.append(cursor.suffix(), ());
2522
2523        drop(cursor);
2524        snapshot.excerpts = new_excerpts;
2525
2526        let edits = Self::sync_diff_transforms(&mut snapshot, edits, DiffChangeKind::BufferEdited);
2527        if !edits.is_empty() {
2528            self.subscriptions.publish(edits);
2529        }
2530        cx.emit(Event::Edited {
2531            edited_buffer: None,
2532        });
2533        cx.emit(Event::ExcerptsExpanded { ids: vec![id] });
2534        cx.notify();
2535    }
2536
2537    pub fn expand_excerpts(
2538        &mut self,
2539        ids: impl IntoIterator<Item = ExcerptId>,
2540        line_count: u32,
2541        direction: ExpandExcerptDirection,
2542        cx: &mut Context<Self>,
2543    ) {
2544        if line_count == 0 {
2545            return;
2546        }
2547        self.sync_mut(cx);
2548        if !self.excerpts_by_path.is_empty() {
2549            self.expand_excerpts_with_paths(ids, line_count, direction, cx);
2550            return;
2551        }
2552        let mut snapshot = self.snapshot.get_mut();
2553
2554        let ids = ids.into_iter().collect::<Vec<_>>();
2555        let locators = snapshot.excerpt_locators_for_ids(ids.iter().copied());
2556        let mut new_excerpts = SumTree::default();
2557        let mut cursor = snapshot
2558            .excerpts
2559            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2560        let mut edits = Vec::<Edit<ExcerptOffset>>::new();
2561
2562        for locator in &locators {
2563            let prefix = cursor.slice(&Some(locator), Bias::Left);
2564            new_excerpts.append(prefix, ());
2565
2566            let mut excerpt = cursor.item().unwrap().clone();
2567            let old_text_len = excerpt.text_summary.len;
2568
2569            let up_line_count = if direction.should_expand_up() {
2570                line_count
2571            } else {
2572                0
2573            };
2574
2575            let start_row = excerpt
2576                .range
2577                .context
2578                .start
2579                .to_point(&excerpt.buffer)
2580                .row
2581                .saturating_sub(up_line_count);
2582            let start_point = Point::new(start_row, 0);
2583            excerpt.range.context.start = excerpt.buffer.anchor_before(start_point);
2584
2585            let down_line_count = if direction.should_expand_down() {
2586                line_count
2587            } else {
2588                0
2589            };
2590
2591            let mut end_point = excerpt.buffer.clip_point(
2592                excerpt.range.context.end.to_point(&excerpt.buffer)
2593                    + Point::new(down_line_count, 0),
2594                Bias::Left,
2595            );
2596            end_point.column = excerpt.buffer.line_len(end_point.row);
2597            excerpt.range.context.end = excerpt.buffer.anchor_after(end_point);
2598            excerpt.max_buffer_row = end_point.row;
2599
2600            excerpt.text_summary = excerpt
2601                .buffer
2602                .text_summary_for_range(excerpt.range.context.clone());
2603
2604            let new_start_offset = ExcerptDimension(new_excerpts.summary().text.len);
2605            let old_start_offset = cursor.start().1;
2606            let new_text_len = excerpt.text_summary.len;
2607            let edit = Edit {
2608                old: old_start_offset..old_start_offset + old_text_len,
2609                new: new_start_offset..new_start_offset + new_text_len,
2610            };
2611
2612            if let Some(last_edit) = edits.last_mut() {
2613                if last_edit.old.end == edit.old.start {
2614                    last_edit.old.end = edit.old.end;
2615                    last_edit.new.end = edit.new.end;
2616                } else {
2617                    edits.push(edit);
2618                }
2619            } else {
2620                edits.push(edit);
2621            }
2622
2623            new_excerpts.push(excerpt, ());
2624
2625            cursor.next();
2626        }
2627
2628        new_excerpts.append(cursor.suffix(), ());
2629
2630        drop(cursor);
2631        snapshot.excerpts = new_excerpts;
2632
2633        let edits = Self::sync_diff_transforms(&mut snapshot, edits, DiffChangeKind::BufferEdited);
2634        if !edits.is_empty() {
2635            self.subscriptions.publish(edits);
2636        }
2637        cx.emit(Event::Edited {
2638            edited_buffer: None,
2639        });
2640        cx.emit(Event::ExcerptsExpanded { ids });
2641        cx.notify();
2642    }
2643
2644    #[ztracing::instrument(skip_all)]
2645    fn sync(&self, cx: &App) {
2646        let changed = self.buffer_changed_since_sync.replace(false);
2647        if !changed {
2648            return;
2649        }
2650        let edits = Self::sync_from_buffer_changes(
2651            &mut self.snapshot.borrow_mut(),
2652            &self.buffers,
2653            &self.diffs,
2654            cx,
2655        );
2656        if !edits.is_empty() {
2657            self.subscriptions.publish(edits);
2658        }
2659    }
2660
2661    fn sync_mut(&mut self, cx: &App) {
2662        let changed = self.buffer_changed_since_sync.replace(false);
2663        if !changed {
2664            return;
2665        }
2666        let edits =
2667            Self::sync_from_buffer_changes(self.snapshot.get_mut(), &self.buffers, &self.diffs, cx);
2668
2669        if !edits.is_empty() {
2670            self.subscriptions.publish(edits);
2671        }
2672    }
2673
2674    fn sync_from_buffer_changes(
2675        snapshot: &mut MultiBufferSnapshot,
2676        buffers: &BTreeMap<BufferId, BufferState>,
2677        diffs: &HashMap<BufferId, DiffState>,
2678        cx: &App,
2679    ) -> Vec<Edit<MultiBufferOffset>> {
2680        let MultiBufferSnapshot {
2681            excerpts,
2682            buffer_paths: _,
2683            diffs: buffer_diff,
2684            diff_transforms: _,
2685            non_text_state_update_count,
2686            edit_count,
2687            is_dirty,
2688            has_deleted_file,
2689            has_conflict,
2690            has_inverted_diff: _,
2691            singleton: _,
2692            trailing_excerpt_update_count: _,
2693            all_diff_hunks_expanded: _,
2694            show_deleted_hunks: _,
2695            use_extended_diff_range: _,
2696            show_headers: _,
2697        } = snapshot;
2698        *is_dirty = false;
2699        *has_deleted_file = false;
2700        *has_conflict = false;
2701
2702        if !diffs.is_empty() {
2703            let mut diffs_to_add = Vec::new();
2704            for (id, diff) in diffs {
2705                // For inverted diffs, we excerpt the diff base texts in the multibuffer
2706                // and use the diff hunk base text ranges to compute diff transforms.
2707                // Those base text ranges are usize, so make sure if the base text changed
2708                // we also update the diff snapshot so that we don't use stale offsets
2709                if buffer_diff.get(id).is_none_or(|existing_diff| {
2710                    if existing_diff.main_buffer.is_none() {
2711                        return false;
2712                    }
2713                    let base_text = diff.diff.read(cx).base_text_buffer().read(cx);
2714                    base_text.remote_id() != existing_diff.base_text().remote_id()
2715                        || base_text
2716                            .version()
2717                            .changed_since(existing_diff.base_text().version())
2718                }) {
2719                    if diffs_to_add.capacity() == 0 {
2720                        // we'd rather overallocate than reallocate as buffer diffs are quite big
2721                        // meaning re-allocations will be fairly expensive
2722                        diffs_to_add.reserve(diffs.len());
2723                    }
2724                    diffs_to_add.push((*id, diff.snapshot(cx)));
2725                }
2726            }
2727            buffer_diff.extend(diffs_to_add);
2728        }
2729
2730        let mut excerpts_to_edit = Vec::new();
2731        let mut non_text_state_updated = false;
2732        let mut edited = false;
2733        for buffer_state in buffers.values() {
2734            let buffer = buffer_state.buffer.read(cx);
2735            let version = buffer.version();
2736            let non_text_state_update_count = buffer.non_text_state_update_count();
2737
2738            let buffer_edited = version.changed_since(&buffer_state.last_version.borrow());
2739            let buffer_non_text_state_updated =
2740                non_text_state_update_count > buffer_state.last_non_text_state_update_count.get();
2741            if buffer_edited || buffer_non_text_state_updated {
2742                *buffer_state.last_version.borrow_mut() = version;
2743                buffer_state
2744                    .last_non_text_state_update_count
2745                    .set(non_text_state_update_count);
2746                excerpts_to_edit.extend(
2747                    buffer_state
2748                        .excerpts
2749                        .iter()
2750                        .map(|locator| (locator, buffer_state.buffer.clone(), buffer_edited)),
2751                );
2752            }
2753
2754            edited |= buffer_edited;
2755            non_text_state_updated |= buffer_non_text_state_updated;
2756            *is_dirty |= buffer.is_dirty();
2757            *has_deleted_file |= buffer
2758                .file()
2759                .is_some_and(|file| file.disk_state().is_deleted());
2760            *has_conflict |= buffer.has_conflict();
2761        }
2762        if edited {
2763            *edit_count += 1;
2764        }
2765        if non_text_state_updated {
2766            *non_text_state_update_count += 1;
2767        }
2768
2769        excerpts_to_edit.sort_unstable_by_key(|&(locator, _, _)| locator);
2770
2771        let mut edits = Vec::new();
2772        let mut new_excerpts = SumTree::default();
2773        let mut cursor = excerpts.cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2774
2775        for (locator, buffer, buffer_edited) in excerpts_to_edit {
2776            new_excerpts.append(cursor.slice(&Some(locator), Bias::Left), ());
2777            let old_excerpt = cursor.item().unwrap();
2778            let buffer = buffer.read(cx);
2779            let buffer_id = buffer.remote_id();
2780            let mut new_excerpt;
2781            if buffer_edited {
2782                edits.extend(
2783                    buffer
2784                        .edits_since_in_range::<usize>(
2785                            old_excerpt.buffer.version(),
2786                            old_excerpt.range.context.clone(),
2787                        )
2788                        .map(|edit| {
2789                            let excerpt_old_start = cursor.start().1;
2790                            let excerpt_new_start =
2791                                ExcerptDimension(new_excerpts.summary().text.len);
2792                            let old_start = excerpt_old_start + edit.old.start;
2793                            let old_end = excerpt_old_start + edit.old.end;
2794                            let new_start = excerpt_new_start + edit.new.start;
2795                            let new_end = excerpt_new_start + edit.new.end;
2796                            Edit {
2797                                old: old_start..old_end,
2798                                new: new_start..new_end,
2799                            }
2800                        }),
2801                );
2802
2803                new_excerpt = Excerpt::new(
2804                    old_excerpt.id,
2805                    locator.clone(),
2806                    buffer_id,
2807                    Arc::new(buffer.snapshot()),
2808                    old_excerpt.range.clone(),
2809                    old_excerpt.has_trailing_newline,
2810                );
2811            } else {
2812                new_excerpt = old_excerpt.clone();
2813                new_excerpt.buffer = Arc::new(buffer.snapshot());
2814            }
2815
2816            new_excerpts.push(new_excerpt, ());
2817            cursor.next();
2818        }
2819        new_excerpts.append(cursor.suffix(), ());
2820
2821        drop(cursor);
2822        *excerpts = new_excerpts;
2823
2824        Self::sync_diff_transforms(snapshot, edits, DiffChangeKind::BufferEdited)
2825    }
2826
2827    fn sync_diff_transforms(
2828        snapshot: &mut MultiBufferSnapshot,
2829        excerpt_edits: Vec<text::Edit<ExcerptOffset>>,
2830        change_kind: DiffChangeKind,
2831    ) -> Vec<Edit<MultiBufferOffset>> {
2832        if excerpt_edits.is_empty() {
2833            return vec![];
2834        }
2835
2836        let mut excerpts = snapshot.excerpts.cursor::<ExcerptOffset>(());
2837        let mut old_diff_transforms = snapshot
2838            .diff_transforms
2839            .cursor::<Dimensions<ExcerptOffset, MultiBufferOffset>>(());
2840        let mut new_diff_transforms = SumTree::default();
2841        let mut old_expanded_hunks = HashSet::default();
2842        let mut output_edits = Vec::new();
2843        let mut output_delta = 0_isize;
2844        let mut at_transform_boundary = true;
2845        let mut end_of_current_insert = None;
2846
2847        let mut excerpt_edits = excerpt_edits.into_iter().peekable();
2848        while let Some(edit) = excerpt_edits.next() {
2849            excerpts.seek_forward(&edit.new.start, Bias::Right);
2850            if excerpts.item().is_none() && *excerpts.start() == edit.new.start {
2851                excerpts.prev();
2852            }
2853
2854            // Keep any transforms that are before the edit.
2855            if at_transform_boundary {
2856                at_transform_boundary = false;
2857                let transforms_before_edit = old_diff_transforms.slice(&edit.old.start, Bias::Left);
2858                Self::append_diff_transforms(&mut new_diff_transforms, transforms_before_edit);
2859                if let Some(transform) = old_diff_transforms.item()
2860                    && old_diff_transforms.end().0 == edit.old.start
2861                    && old_diff_transforms.start().0 < edit.old.start
2862                {
2863                    Self::push_diff_transform(&mut new_diff_transforms, transform.clone());
2864                    old_diff_transforms.next();
2865                }
2866            }
2867
2868            // Compute the start of the edit in output coordinates.
2869            let edit_start_overshoot = edit.old.start - old_diff_transforms.start().0;
2870            let edit_old_start = old_diff_transforms.start().1 + edit_start_overshoot;
2871            let edit_new_start =
2872                MultiBufferOffset((edit_old_start.0 as isize + output_delta) as usize);
2873
2874            let changed_diff_hunks = Self::recompute_diff_transforms_for_edit(
2875                &edit,
2876                &mut excerpts,
2877                &mut old_diff_transforms,
2878                &mut new_diff_transforms,
2879                &mut end_of_current_insert,
2880                &mut old_expanded_hunks,
2881                snapshot,
2882                change_kind,
2883            );
2884
2885            // Compute the end of the edit in output coordinates.
2886            let edit_old_end_overshoot = edit.old.end - old_diff_transforms.start().0;
2887            let edit_new_end_overshoot = edit.new.end - new_diff_transforms.summary().excerpt_len();
2888            let edit_old_end = old_diff_transforms.start().1 + edit_old_end_overshoot;
2889            let edit_new_end = new_diff_transforms.summary().output.len + edit_new_end_overshoot;
2890            let output_edit = Edit {
2891                old: edit_old_start..edit_old_end,
2892                new: edit_new_start..edit_new_end,
2893            };
2894
2895            output_delta += (output_edit.new.end - output_edit.new.start) as isize;
2896            output_delta -= (output_edit.old.end - output_edit.old.start) as isize;
2897            if changed_diff_hunks || matches!(change_kind, DiffChangeKind::BufferEdited) {
2898                output_edits.push(output_edit);
2899            }
2900
2901            // If this is the last edit that intersects the current diff transform,
2902            // then recreate the content up to the end of this transform, to prepare
2903            // for reusing additional slices of the old transforms.
2904            if excerpt_edits
2905                .peek()
2906                .is_none_or(|next_edit| next_edit.old.start >= old_diff_transforms.end().0)
2907            {
2908                let keep_next_old_transform = (old_diff_transforms.start().0 >= edit.old.end)
2909                    && match old_diff_transforms.item() {
2910                        Some(DiffTransform::BufferContent {
2911                            inserted_hunk_info: Some(hunk),
2912                            ..
2913                        }) => excerpts.item().is_some_and(|excerpt| {
2914                            if let Some(diff) = snapshot.diffs.get(&excerpt.buffer_id)
2915                                && diff.main_buffer.is_some()
2916                            {
2917                                return true;
2918                            }
2919                            hunk.hunk_start_anchor.is_valid(&excerpt.buffer)
2920                        }),
2921                        _ => true,
2922                    };
2923
2924                let mut excerpt_offset = edit.new.end;
2925                if !keep_next_old_transform {
2926                    excerpt_offset += old_diff_transforms.end().0 - edit.old.end;
2927                    old_diff_transforms.next();
2928                }
2929
2930                old_expanded_hunks.clear();
2931                Self::push_buffer_content_transform(
2932                    snapshot,
2933                    &mut new_diff_transforms,
2934                    excerpt_offset,
2935                    end_of_current_insert,
2936                );
2937                at_transform_boundary = true;
2938            }
2939        }
2940
2941        // Keep any transforms that are after the last edit.
2942        Self::append_diff_transforms(&mut new_diff_transforms, old_diff_transforms.suffix());
2943
2944        // Ensure there's always at least one buffer content transform.
2945        if new_diff_transforms.is_empty() {
2946            new_diff_transforms.push(
2947                DiffTransform::BufferContent {
2948                    summary: Default::default(),
2949                    inserted_hunk_info: None,
2950                },
2951                (),
2952            );
2953        }
2954
2955        drop(old_diff_transforms);
2956        drop(excerpts);
2957        snapshot.diff_transforms = new_diff_transforms;
2958        snapshot.edit_count += 1;
2959
2960        #[cfg(any(test, feature = "test-support"))]
2961        snapshot.check_invariants();
2962        output_edits
2963    }
2964
2965    fn recompute_diff_transforms_for_edit(
2966        edit: &Edit<ExcerptOffset>,
2967        excerpts: &mut Cursor<Excerpt, ExcerptOffset>,
2968        old_diff_transforms: &mut Cursor<
2969            DiffTransform,
2970            Dimensions<ExcerptOffset, MultiBufferOffset>,
2971        >,
2972        new_diff_transforms: &mut SumTree<DiffTransform>,
2973        end_of_current_insert: &mut Option<(ExcerptOffset, DiffTransformHunkInfo)>,
2974        old_expanded_hunks: &mut HashSet<DiffTransformHunkInfo>,
2975        snapshot: &MultiBufferSnapshot,
2976        change_kind: DiffChangeKind,
2977    ) -> bool {
2978        log::trace!(
2979            "recomputing diff transform for edit {:?} => {:?}",
2980            edit.old.start..edit.old.end,
2981            edit.new.start..edit.new.end
2982        );
2983
2984        // Record which hunks were previously expanded.
2985        while let Some(item) = old_diff_transforms.item() {
2986            if let Some(hunk_info) = item.hunk_info() {
2987                log::trace!(
2988                    "previously expanded hunk at {:?}",
2989                    old_diff_transforms.start()
2990                );
2991                old_expanded_hunks.insert(hunk_info);
2992            }
2993            if old_diff_transforms.end().0 > edit.old.end {
2994                break;
2995            }
2996            old_diff_transforms.next();
2997        }
2998
2999        // Avoid querying diff hunks if there's no possibility of hunks being expanded.
3000        // For inverted diffs, hunks are always shown, so we can't skip this.
3001        let all_diff_hunks_expanded = snapshot.all_diff_hunks_expanded;
3002        if old_expanded_hunks.is_empty()
3003            && change_kind == DiffChangeKind::BufferEdited
3004            && !all_diff_hunks_expanded
3005            && !snapshot.has_inverted_diff
3006        {
3007            return false;
3008        }
3009
3010        // Visit each excerpt that intersects the edit.
3011        let mut did_expand_hunks = false;
3012        while let Some(excerpt) = excerpts.item() {
3013            // Recompute the expanded hunks in the portion of the excerpt that
3014            // intersects the edit.
3015            if let Some(diff) = snapshot.diffs.get(&excerpt.buffer_id) {
3016                let buffer = &excerpt.buffer;
3017                let excerpt_start = *excerpts.start();
3018                let excerpt_end = excerpt_start + excerpt.text_summary.len;
3019                let excerpt_buffer_start = excerpt.range.context.start.to_offset(buffer);
3020                let excerpt_buffer_end = excerpt_buffer_start + excerpt.text_summary.len;
3021                let edit_buffer_start =
3022                    excerpt_buffer_start + edit.new.start.saturating_sub(excerpt_start);
3023                let edit_buffer_end =
3024                    excerpt_buffer_start + edit.new.end.saturating_sub(excerpt_start);
3025                let edit_buffer_end = edit_buffer_end.min(excerpt_buffer_end);
3026
3027                if let Some(main_buffer) = &diff.main_buffer {
3028                    for hunk in diff.hunks_intersecting_base_text_range(
3029                        edit_buffer_start..edit_buffer_end,
3030                        main_buffer,
3031                    ) {
3032                        did_expand_hunks = true;
3033                        let hunk_buffer_range = hunk.diff_base_byte_range.clone();
3034                        if hunk_buffer_range.start < excerpt_buffer_start {
3035                            log::trace!("skipping hunk that starts before excerpt");
3036                            continue;
3037                        }
3038                        hunk_buffer_range.end.to_point(&excerpt.buffer);
3039                        let hunk_excerpt_start = excerpt_start
3040                            + hunk_buffer_range.start.saturating_sub(excerpt_buffer_start);
3041                        let hunk_excerpt_end = excerpt_end
3042                            .min(excerpt_start + (hunk_buffer_range.end - excerpt_buffer_start));
3043                        Self::push_buffer_content_transform(
3044                            snapshot,
3045                            new_diff_transforms,
3046                            hunk_excerpt_start,
3047                            *end_of_current_insert,
3048                        );
3049                        if !hunk_buffer_range.is_empty() {
3050                            let hunk_info = DiffTransformHunkInfo {
3051                                excerpt_id: excerpt.id,
3052                                hunk_start_anchor: hunk.buffer_range.start,
3053                                hunk_secondary_status: hunk.secondary_status,
3054                                is_logically_deleted: true,
3055                            };
3056                            *end_of_current_insert =
3057                                Some((hunk_excerpt_end.min(excerpt_end), hunk_info));
3058                        }
3059                    }
3060                } else {
3061                    let edit_anchor_range = buffer.anchor_before(edit_buffer_start)
3062                        ..buffer.anchor_after(edit_buffer_end);
3063                    for hunk in diff.hunks_intersecting_range(edit_anchor_range, buffer) {
3064                        if hunk.is_created_file() && !all_diff_hunks_expanded {
3065                            continue;
3066                        }
3067
3068                        let hunk_buffer_range = hunk.buffer_range.to_offset(buffer);
3069                        if hunk_buffer_range.start < excerpt_buffer_start {
3070                            log::trace!("skipping hunk that starts before excerpt");
3071                            continue;
3072                        }
3073
3074                        let hunk_info = DiffTransformHunkInfo {
3075                            excerpt_id: excerpt.id,
3076                            hunk_start_anchor: hunk.buffer_range.start,
3077                            hunk_secondary_status: hunk.secondary_status,
3078                            is_logically_deleted: false,
3079                        };
3080
3081                        let hunk_excerpt_start = excerpt_start
3082                            + hunk_buffer_range.start.saturating_sub(excerpt_buffer_start);
3083                        let hunk_excerpt_end = excerpt_end
3084                            .min(excerpt_start + (hunk_buffer_range.end - excerpt_buffer_start));
3085
3086                        Self::push_buffer_content_transform(
3087                            snapshot,
3088                            new_diff_transforms,
3089                            hunk_excerpt_start,
3090                            *end_of_current_insert,
3091                        );
3092
3093                        // For every existing hunk, determine if it was previously expanded
3094                        // and if it should currently be expanded.
3095                        let was_previously_expanded = old_expanded_hunks.contains(&hunk_info);
3096                        let should_expand_hunk = match &change_kind {
3097                            DiffChangeKind::DiffUpdated { base_changed: true } => {
3098                                was_previously_expanded || all_diff_hunks_expanded
3099                            }
3100                            DiffChangeKind::ExpandOrCollapseHunks { expand } => {
3101                                let intersects = hunk_buffer_range.is_empty()
3102                                    || hunk_buffer_range.end > edit_buffer_start;
3103                                if *expand {
3104                                    intersects || was_previously_expanded || all_diff_hunks_expanded
3105                                } else {
3106                                    !intersects
3107                                        && (was_previously_expanded || all_diff_hunks_expanded)
3108                                }
3109                            }
3110                            _ => was_previously_expanded || all_diff_hunks_expanded,
3111                        };
3112
3113                        if should_expand_hunk {
3114                            did_expand_hunks = true;
3115                            log::trace!(
3116                                "expanding hunk {:?}, excerpt:{:?}",
3117                                hunk_excerpt_start..hunk_excerpt_end,
3118                                excerpt.id
3119                            );
3120
3121                            if !hunk.diff_base_byte_range.is_empty()
3122                                && hunk_buffer_range.start >= edit_buffer_start
3123                                && hunk_buffer_range.start <= excerpt_buffer_end
3124                                && snapshot.show_deleted_hunks
3125                            {
3126                                let base_text = diff.base_text();
3127                                let mut text_cursor =
3128                                    base_text.as_rope().cursor(hunk.diff_base_byte_range.start);
3129                                let mut base_text_summary = text_cursor
3130                                    .summary::<TextSummary>(hunk.diff_base_byte_range.end);
3131
3132                                let mut has_trailing_newline = false;
3133                                if base_text_summary.last_line_chars > 0 {
3134                                    base_text_summary += TextSummary::newline();
3135                                    has_trailing_newline = true;
3136                                }
3137
3138                                new_diff_transforms.push(
3139                                    DiffTransform::DeletedHunk {
3140                                        base_text_byte_range: hunk.diff_base_byte_range.clone(),
3141                                        summary: base_text_summary,
3142                                        buffer_id: excerpt.buffer_id,
3143                                        hunk_info,
3144                                        has_trailing_newline,
3145                                    },
3146                                    (),
3147                                );
3148                            }
3149
3150                            if !hunk_buffer_range.is_empty() {
3151                                *end_of_current_insert =
3152                                    Some((hunk_excerpt_end.min(excerpt_end), hunk_info));
3153                            }
3154                        }
3155                    }
3156                }
3157            }
3158
3159            if excerpts.end() <= edit.new.end {
3160                excerpts.next();
3161            } else {
3162                break;
3163            }
3164        }
3165
3166        did_expand_hunks || !old_expanded_hunks.is_empty()
3167    }
3168
3169    fn append_diff_transforms(
3170        new_transforms: &mut SumTree<DiffTransform>,
3171        subtree: SumTree<DiffTransform>,
3172    ) {
3173        if let Some(DiffTransform::BufferContent {
3174            inserted_hunk_info,
3175            summary,
3176        }) = subtree.first()
3177            && Self::extend_last_buffer_content_transform(
3178                new_transforms,
3179                *inserted_hunk_info,
3180                *summary,
3181            )
3182        {
3183            let mut cursor = subtree.cursor::<()>(());
3184            cursor.next();
3185            cursor.next();
3186            new_transforms.append(cursor.suffix(), ());
3187            return;
3188        }
3189        new_transforms.append(subtree, ());
3190    }
3191
3192    fn push_diff_transform(new_transforms: &mut SumTree<DiffTransform>, transform: DiffTransform) {
3193        if let DiffTransform::BufferContent {
3194            inserted_hunk_info: inserted_hunk_anchor,
3195            summary,
3196        } = transform
3197            && Self::extend_last_buffer_content_transform(
3198                new_transforms,
3199                inserted_hunk_anchor,
3200                summary,
3201            )
3202        {
3203            return;
3204        }
3205        new_transforms.push(transform, ());
3206    }
3207
3208    fn push_buffer_content_transform(
3209        old_snapshot: &MultiBufferSnapshot,
3210        new_transforms: &mut SumTree<DiffTransform>,
3211        end_offset: ExcerptOffset,
3212        current_inserted_hunk: Option<(ExcerptOffset, DiffTransformHunkInfo)>,
3213    ) {
3214        let inserted_region = current_inserted_hunk.map(|(insertion_end_offset, hunk_info)| {
3215            (end_offset.min(insertion_end_offset), Some(hunk_info))
3216        });
3217        let unchanged_region = [(end_offset, None)];
3218
3219        for (end_offset, inserted_hunk_info) in inserted_region.into_iter().chain(unchanged_region)
3220        {
3221            let start_offset = new_transforms.summary().excerpt_len();
3222            if end_offset <= start_offset {
3223                continue;
3224            }
3225            let summary_to_add = old_snapshot
3226                .text_summary_for_excerpt_offset_range::<MBTextSummary>(start_offset..end_offset);
3227
3228            if !Self::extend_last_buffer_content_transform(
3229                new_transforms,
3230                inserted_hunk_info,
3231                summary_to_add,
3232            ) {
3233                new_transforms.push(
3234                    DiffTransform::BufferContent {
3235                        summary: summary_to_add,
3236                        inserted_hunk_info,
3237                    },
3238                    (),
3239                )
3240            }
3241        }
3242    }
3243
3244    fn extend_last_buffer_content_transform(
3245        new_transforms: &mut SumTree<DiffTransform>,
3246        new_inserted_hunk_info: Option<DiffTransformHunkInfo>,
3247        summary_to_add: MBTextSummary,
3248    ) -> bool {
3249        let mut did_extend = false;
3250        new_transforms.update_last(
3251            |last_transform| {
3252                if let DiffTransform::BufferContent {
3253                    summary,
3254                    inserted_hunk_info: inserted_hunk_anchor,
3255                } = last_transform
3256                    && *inserted_hunk_anchor == new_inserted_hunk_info
3257                {
3258                    *summary += summary_to_add;
3259                    did_extend = true;
3260                }
3261            },
3262            (),
3263        );
3264        did_extend
3265    }
3266
3267    pub fn toggle_single_diff_hunk(&mut self, range: Range<Anchor>, cx: &mut Context<Self>) {
3268        let snapshot = self.snapshot(cx);
3269        let excerpt_id = range.end.excerpt_id;
3270        let point_range = range.to_point(&snapshot);
3271        let expand = !self.single_hunk_is_expanded(range, cx);
3272        let edits =
3273            self.expand_or_collapse_diff_hunks_inner([(point_range, excerpt_id)], expand, cx);
3274        if !edits.is_empty() {
3275            self.subscriptions.publish(edits);
3276        }
3277        cx.emit(Event::DiffHunksToggled);
3278        cx.emit(Event::Edited {
3279            edited_buffer: None,
3280        });
3281    }
3282}
3283
3284fn build_excerpt_ranges(
3285    ranges: impl IntoIterator<Item = Range<Point>>,
3286    context_line_count: u32,
3287    buffer_snapshot: &BufferSnapshot,
3288) -> Vec<ExcerptRange<Point>> {
3289    ranges
3290        .into_iter()
3291        .map(|range| {
3292            let start_row = range.start.row.saturating_sub(context_line_count);
3293            let start = Point::new(start_row, 0);
3294            let end_row = (range.end.row + context_line_count).min(buffer_snapshot.max_point().row);
3295            let end = Point::new(end_row, buffer_snapshot.line_len(end_row));
3296            ExcerptRange {
3297                context: start..end,
3298                primary: range,
3299            }
3300        })
3301        .collect()
3302}
3303
3304#[cfg(any(test, feature = "test-support"))]
3305impl MultiBuffer {
3306    pub fn build_simple(text: &str, cx: &mut gpui::App) -> Entity<Self> {
3307        let buffer = cx.new(|cx| Buffer::local(text, cx));
3308        cx.new(|cx| Self::singleton(buffer, cx))
3309    }
3310
3311    pub fn build_multi<const COUNT: usize>(
3312        excerpts: [(&str, Vec<Range<Point>>); COUNT],
3313        cx: &mut gpui::App,
3314    ) -> Entity<Self> {
3315        let multi = cx.new(|_| Self::new(Capability::ReadWrite));
3316        for (ix, (text, ranges)) in excerpts.into_iter().enumerate() {
3317            let buffer = cx.new(|cx| Buffer::local(text, cx));
3318            let snapshot = buffer.read(cx).snapshot();
3319            let excerpt_ranges = ranges
3320                .into_iter()
3321                .map(ExcerptRange::new)
3322                .collect::<Vec<_>>();
3323            multi.update(cx, |multi, cx| {
3324                multi.set_excerpt_ranges_for_path(
3325                    PathKey::sorted(ix as u64),
3326                    buffer,
3327                    &snapshot,
3328                    excerpt_ranges,
3329                    cx,
3330                )
3331            });
3332        }
3333
3334        multi
3335    }
3336
3337    pub fn build_from_buffer(buffer: Entity<Buffer>, cx: &mut gpui::App) -> Entity<Self> {
3338        cx.new(|cx| Self::singleton(buffer, cx))
3339    }
3340
3341    pub fn build_random(rng: &mut impl rand::Rng, cx: &mut gpui::App) -> Entity<Self> {
3342        cx.new(|cx| {
3343            let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3344            let mutation_count = rng.random_range(1..=5);
3345            multibuffer.randomly_edit_excerpts(rng, mutation_count, cx);
3346            multibuffer
3347        })
3348    }
3349
3350    pub fn randomly_edit(
3351        &mut self,
3352        rng: &mut impl rand::Rng,
3353        edit_count: usize,
3354        cx: &mut Context<Self>,
3355    ) {
3356        use util::RandomCharIter;
3357
3358        let snapshot = self.read(cx);
3359        let mut edits: Vec<(Range<MultiBufferOffset>, Arc<str>)> = Vec::new();
3360        let mut last_end = None;
3361        for _ in 0..edit_count {
3362            if last_end.is_some_and(|last_end| last_end >= snapshot.len()) {
3363                break;
3364            }
3365
3366            let new_start = last_end.map_or(MultiBufferOffset::ZERO, |last_end| last_end + 1usize);
3367            let end =
3368                snapshot.clip_offset(rng.random_range(new_start..=snapshot.len()), Bias::Right);
3369            let start = snapshot.clip_offset(rng.random_range(new_start..=end), Bias::Right);
3370            last_end = Some(end);
3371
3372            let mut range = start..end;
3373            if rng.random_bool(0.2) {
3374                mem::swap(&mut range.start, &mut range.end);
3375            }
3376
3377            let new_text_len = rng.random_range(0..10);
3378            let new_text: String = RandomCharIter::new(&mut *rng).take(new_text_len).collect();
3379
3380            edits.push((range, new_text.into()));
3381        }
3382        log::info!("mutating multi-buffer with {:?}", edits);
3383        drop(snapshot);
3384
3385        self.edit(edits, None, cx);
3386    }
3387
3388    pub fn randomly_edit_excerpts(
3389        &mut self,
3390        rng: &mut impl rand::Rng,
3391        mutation_count: usize,
3392        cx: &mut Context<Self>,
3393    ) {
3394        use rand::prelude::*;
3395        use std::env;
3396        use util::RandomCharIter;
3397
3398        let max_excerpts = env::var("MAX_EXCERPTS")
3399            .map(|i| i.parse().expect("invalid `MAX_EXCERPTS` variable"))
3400            .unwrap_or(5);
3401
3402        let mut buffers = Vec::new();
3403        for _ in 0..mutation_count {
3404            if rng.random_bool(0.05) {
3405                log::info!("Clearing multi-buffer");
3406                self.clear(cx);
3407                continue;
3408            } else if rng.random_bool(0.1) && !self.excerpt_ids().is_empty() {
3409                let ids = self.excerpt_ids();
3410                let mut excerpts = HashSet::default();
3411                for _ in 0..rng.random_range(0..ids.len()) {
3412                    excerpts.extend(ids.choose(rng).copied());
3413                }
3414
3415                let line_count = rng.random_range(0..5);
3416
3417                log::info!("Expanding excerpts {excerpts:?} by {line_count} lines");
3418
3419                self.expand_excerpts(
3420                    excerpts.iter().cloned(),
3421                    line_count,
3422                    ExpandExcerptDirection::UpAndDown,
3423                    cx,
3424                );
3425                continue;
3426            }
3427
3428            let excerpt_ids = self.excerpt_ids();
3429            if excerpt_ids.is_empty() || (rng.random() && excerpt_ids.len() < max_excerpts) {
3430                let buffer_handle = if rng.random() || self.buffers.is_empty() {
3431                    let text = RandomCharIter::new(&mut *rng).take(10).collect::<String>();
3432                    buffers.push(cx.new(|cx| Buffer::local(text, cx)));
3433                    let buffer = buffers.last().unwrap().read(cx);
3434                    log::info!(
3435                        "Creating new buffer {} with text: {:?}",
3436                        buffer.remote_id(),
3437                        buffer.text()
3438                    );
3439                    buffers.last().unwrap().clone()
3440                } else {
3441                    self.buffers.values().choose(rng).unwrap().buffer.clone()
3442                };
3443
3444                let buffer = buffer_handle.read(cx);
3445                let buffer_text = buffer.text();
3446                let ranges = (0..rng.random_range(0..5))
3447                    .map(|_| {
3448                        let end_ix =
3449                            buffer.clip_offset(rng.random_range(0..=buffer.len()), Bias::Right);
3450                        let start_ix = buffer.clip_offset(rng.random_range(0..=end_ix), Bias::Left);
3451                        ExcerptRange::new(start_ix..end_ix)
3452                    })
3453                    .collect::<Vec<_>>();
3454                log::info!(
3455                    "Inserting excerpts from buffer {} and ranges {:?}: {:?}",
3456                    buffer_handle.read(cx).remote_id(),
3457                    ranges.iter().map(|r| &r.context).collect::<Vec<_>>(),
3458                    ranges
3459                        .iter()
3460                        .map(|r| &buffer_text[r.context.clone()])
3461                        .collect::<Vec<_>>()
3462                );
3463
3464                let excerpt_id =
3465                    self.insert_excerpts_after(ExcerptId::max(), buffer_handle, ranges, cx);
3466                log::info!("Inserted with ids: {:?}", excerpt_id);
3467            } else {
3468                let remove_count = rng.random_range(1..=excerpt_ids.len());
3469                let mut excerpts_to_remove = excerpt_ids
3470                    .choose_multiple(rng, remove_count)
3471                    .cloned()
3472                    .collect::<Vec<_>>();
3473                let snapshot = self.snapshot.borrow();
3474                excerpts_to_remove.sort_unstable_by(|a, b| a.cmp(b, &snapshot));
3475                drop(snapshot);
3476                log::info!("Removing excerpts {:?}", excerpts_to_remove);
3477                self.remove_excerpts(excerpts_to_remove, cx);
3478            }
3479        }
3480    }
3481
3482    pub fn randomly_mutate(
3483        &mut self,
3484        rng: &mut impl rand::Rng,
3485        mutation_count: usize,
3486        cx: &mut Context<Self>,
3487    ) {
3488        use rand::prelude::*;
3489
3490        if rng.random_bool(0.7) || self.singleton {
3491            let buffer = self
3492                .buffers
3493                .values()
3494                .choose(rng)
3495                .map(|state| state.buffer.clone());
3496
3497            if let Some(buffer) = buffer {
3498                buffer.update(cx, |buffer, cx| {
3499                    if rng.random() {
3500                        buffer.randomly_edit(rng, mutation_count, cx);
3501                    } else {
3502                        buffer.randomly_undo_redo(rng, cx);
3503                    }
3504                });
3505            } else {
3506                self.randomly_edit(rng, mutation_count, cx);
3507            }
3508        } else {
3509            self.randomly_edit_excerpts(rng, mutation_count, cx);
3510        }
3511
3512        self.check_invariants(cx);
3513    }
3514
3515    fn check_invariants(&self, cx: &App) {
3516        self.read(cx).check_invariants();
3517    }
3518}
3519
3520impl EventEmitter<Event> for MultiBuffer {}
3521
3522impl MultiBufferSnapshot {
3523    pub fn text(&self) -> String {
3524        self.chunks(MultiBufferOffset::ZERO..self.len(), false)
3525            .map(|chunk| chunk.text)
3526            .collect()
3527    }
3528
3529    pub fn reversed_chars_at<T: ToOffset>(&self, position: T) -> impl Iterator<Item = char> + '_ {
3530        self.reversed_chunks_in_range(MultiBufferOffset::ZERO..position.to_offset(self))
3531            .flat_map(|c| c.chars().rev())
3532    }
3533
3534    fn reversed_chunks_in_range(
3535        &self,
3536        range: Range<MultiBufferOffset>,
3537    ) -> ReversedMultiBufferChunks<'_> {
3538        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
3539        cursor.seek(&range.end);
3540        let current_chunks = cursor.region().as_ref().map(|region| {
3541            let start_overshoot = range.start.saturating_sub(region.range.start);
3542            let end_overshoot = range.end - region.range.start;
3543            let end = (region.buffer_range.start + end_overshoot).min(region.buffer_range.end);
3544            let start = region.buffer_range.start + start_overshoot;
3545            region.buffer.reversed_chunks_in_range(start..end)
3546        });
3547        ReversedMultiBufferChunks {
3548            cursor,
3549            current_chunks,
3550            start: range.start,
3551            offset: range.end,
3552        }
3553    }
3554
3555    pub fn chars_at<T: ToOffset>(&self, position: T) -> impl Iterator<Item = char> + '_ {
3556        let offset = position.to_offset(self);
3557        self.text_for_range(offset..self.len())
3558            .flat_map(|chunk| chunk.chars())
3559    }
3560
3561    pub fn text_for_range<T: ToOffset>(&self, range: Range<T>) -> impl Iterator<Item = &str> + '_ {
3562        self.chunks(range, false).map(|chunk| chunk.text)
3563    }
3564
3565    pub fn is_line_blank(&self, row: MultiBufferRow) -> bool {
3566        self.text_for_range(Point::new(row.0, 0)..Point::new(row.0, self.line_len(row)))
3567            .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
3568    }
3569
3570    pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
3571    where
3572        T: ToOffset,
3573    {
3574        let position = position.to_offset(self);
3575        position == self.clip_offset(position, Bias::Left)
3576            && self
3577                .bytes_in_range(position..self.len())
3578                .flatten()
3579                .copied()
3580                .take(needle.len())
3581                .eq(needle.bytes())
3582    }
3583
3584    pub fn diff_hunks(&self) -> impl Iterator<Item = MultiBufferDiffHunk> + '_ {
3585        self.diff_hunks_in_range(Anchor::min()..Anchor::max())
3586    }
3587
3588    pub fn diff_hunks_in_range<T: ToPoint>(
3589        &self,
3590        range: Range<T>,
3591    ) -> impl Iterator<Item = MultiBufferDiffHunk> + '_ {
3592        let query_range = range.start.to_point(self)..range.end.to_point(self);
3593        self.lift_buffer_metadata(query_range.clone(), move |buffer, buffer_range| {
3594            let diff = self.diffs.get(&buffer.remote_id())?;
3595            let iter = if let Some(main_buffer) = &diff.main_buffer {
3596                let buffer_start = buffer.point_to_offset(buffer_range.start);
3597                let buffer_end = buffer.point_to_offset(buffer_range.end);
3598                itertools::Either::Left(
3599                    diff.hunks_intersecting_base_text_range(buffer_start..buffer_end, main_buffer)
3600                        .map(move |hunk| (hunk, buffer, true)),
3601                )
3602            } else {
3603                let buffer_start = buffer.anchor_before(buffer_range.start);
3604                let buffer_end = buffer.anchor_after(buffer_range.end);
3605                itertools::Either::Right(
3606                    diff.hunks_intersecting_range(buffer_start..buffer_end, buffer)
3607                        .map(move |hunk| (hunk, buffer, false)),
3608                )
3609            };
3610            Some(iter.filter_map(|(hunk, buffer, is_inverted)| {
3611                if hunk.is_created_file() && !self.all_diff_hunks_expanded {
3612                    return None;
3613                }
3614                let range = if is_inverted {
3615                    hunk.diff_base_byte_range.to_point(&buffer)
3616                } else {
3617                    hunk.range.clone()
3618                };
3619                Some((range, (hunk, is_inverted)))
3620            }))
3621        })
3622        .filter_map(move |(range, (hunk, is_inverted), excerpt)| {
3623            if range.start != range.end && range.end == query_range.start && !hunk.range.is_empty()
3624            {
3625                return None;
3626            }
3627            let end_row = if range.end.column == 0 {
3628                range.end.row
3629            } else {
3630                range.end.row + 1
3631            };
3632
3633            let word_diffs =
3634                (!hunk.base_word_diffs.is_empty() || !hunk.buffer_word_diffs.is_empty())
3635                    .then(|| {
3636                        let mut word_diffs = Vec::new();
3637
3638                        if self.show_deleted_hunks || is_inverted {
3639                            let hunk_start_offset = if is_inverted {
3640                                Anchor::text(
3641                                    excerpt.id,
3642                                    excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start),
3643                                )
3644                                .to_offset(self)
3645                            } else {
3646                                Anchor::text(excerpt.id, hunk.buffer_range.start).to_offset(self)
3647                            };
3648
3649                            word_diffs.extend(hunk.base_word_diffs.iter().map(|diff| {
3650                                hunk_start_offset + diff.start..hunk_start_offset + diff.end
3651                            }));
3652                        }
3653
3654                        if !is_inverted {
3655                            word_diffs.extend(hunk.buffer_word_diffs.into_iter().map(|diff| {
3656                                Anchor::range_in_buffer(excerpt.id, diff).to_offset(self)
3657                            }));
3658                        }
3659                        word_diffs
3660                    })
3661                    .unwrap_or_default();
3662
3663            let buffer_range = if is_inverted {
3664                excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start)
3665                    ..excerpt.buffer.anchor_before(hunk.diff_base_byte_range.end)
3666            } else {
3667                hunk.buffer_range.clone()
3668            };
3669            let status_kind = if hunk.buffer_range.start == hunk.buffer_range.end {
3670                DiffHunkStatusKind::Deleted
3671            } else if hunk.diff_base_byte_range.is_empty() {
3672                DiffHunkStatusKind::Added
3673            } else {
3674                DiffHunkStatusKind::Modified
3675            };
3676            Some(MultiBufferDiffHunk {
3677                row_range: MultiBufferRow(range.start.row)..MultiBufferRow(end_row),
3678                buffer_id: excerpt.buffer_id,
3679                excerpt_id: excerpt.id,
3680                buffer_range,
3681                word_diffs,
3682                diff_base_byte_range: BufferOffset(hunk.diff_base_byte_range.start)
3683                    ..BufferOffset(hunk.diff_base_byte_range.end),
3684                status: DiffHunkStatus {
3685                    kind: status_kind,
3686                    secondary: hunk.secondary_status,
3687                },
3688            })
3689        })
3690    }
3691
3692    fn excerpts_for_range<T: ToOffset>(
3693        &self,
3694        range: Range<T>,
3695    ) -> impl Iterator<Item = &Excerpt> + '_ {
3696        let range = range.start.to_offset(self)..range.end.to_offset(self);
3697        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
3698        cursor.seek(&range.start);
3699        std::iter::from_fn(move || {
3700            let region = cursor.region()?;
3701            if region.range.start > range.end
3702                || region.range.start == range.end && region.range.start > range.start
3703            {
3704                return None;
3705            }
3706            let excerpt = region.excerpt;
3707            cursor.next_excerpt_forwards();
3708            Some(excerpt)
3709        })
3710    }
3711
3712    pub fn excerpt_ids_for_range<T: ToOffset>(
3713        &self,
3714        range: Range<T>,
3715    ) -> impl Iterator<Item = ExcerptId> + '_ {
3716        self.excerpts_for_range(range).map(|excerpt| excerpt.id)
3717    }
3718
3719    pub fn buffer_ids_for_range<T: ToOffset>(
3720        &self,
3721        range: Range<T>,
3722    ) -> impl Iterator<Item = BufferId> + '_ {
3723        self.excerpts_for_range(range)
3724            .map(|excerpt| excerpt.buffer_id)
3725    }
3726
3727    /// Resolves the given [`text::Anchor`]s to [`crate::Anchor`]s if the anchor is within a visible excerpt.
3728    ///
3729    /// The passed in anchors must be ordered.
3730    pub fn text_anchors_to_visible_anchors(
3731        &self,
3732        anchors: impl IntoIterator<Item = text::Anchor>,
3733    ) -> Vec<Option<Anchor>> {
3734        let anchors = anchors.into_iter();
3735        let mut result = Vec::with_capacity(anchors.size_hint().0);
3736        let mut anchors = anchors.peekable();
3737        let mut cursor = self.excerpts.cursor::<Option<&Locator>>(());
3738        'anchors: while let Some(anchor) = anchors.peek() {
3739            let Some(buffer_id) = anchor.buffer_id else {
3740                anchors.next();
3741                result.push(None);
3742                continue 'anchors;
3743            };
3744            let mut same_buffer_anchors =
3745                anchors.peeking_take_while(|a| a.buffer_id.is_some_and(|b| buffer_id == b));
3746
3747            if let Some(locators) = self.buffer_paths.get(&buffer_id) {
3748                let Some(mut next) = same_buffer_anchors.next() else {
3749                    continue 'anchors;
3750                };
3751                'excerpts: for locator in locators.iter() {
3752                    if cursor.seek_forward(&Some(locator), Bias::Left)
3753                        && let Some(excerpt) = cursor.item()
3754                    {
3755                        loop {
3756                            // anchor is before the first excerpt
3757                            if excerpt
3758                                .range
3759                                .context
3760                                .start
3761                                .cmp(&next, &excerpt.buffer)
3762                                .is_gt()
3763                            {
3764                                // so we skip it and try the next anchor
3765                                result.push(None);
3766                                match same_buffer_anchors.next() {
3767                                    Some(anchor) => next = anchor,
3768                                    None => continue 'anchors,
3769                                }
3770                            // anchor is within the excerpt
3771                            } else if excerpt
3772                                .range
3773                                .context
3774                                .end
3775                                .cmp(&next, &excerpt.buffer)
3776                                .is_ge()
3777                            {
3778                                // record it and all following anchors that are within
3779                                result.push(Some(Anchor::text(excerpt.id, next)));
3780                                result.extend(
3781                                    same_buffer_anchors
3782                                        .peeking_take_while(|a| {
3783                                            excerpt
3784                                                .range
3785                                                .context
3786                                                .end
3787                                                .cmp(a, &excerpt.buffer)
3788                                                .is_ge()
3789                                        })
3790                                        .map(|a| Some(Anchor::text(excerpt.id, a))),
3791                                );
3792                                match same_buffer_anchors.next() {
3793                                    Some(anchor) => next = anchor,
3794                                    None => continue 'anchors,
3795                                }
3796                            // anchor is after the excerpt, try the next one
3797                            } else {
3798                                continue 'excerpts;
3799                            }
3800                        }
3801                    }
3802                }
3803                // account for `next`
3804                result.push(None);
3805            }
3806            result.extend(same_buffer_anchors.map(|_| None));
3807        }
3808
3809        result
3810    }
3811
3812    pub fn ranges_to_buffer_ranges<T: ToOffset>(
3813        &self,
3814        ranges: impl Iterator<Item = Range<T>>,
3815    ) -> impl Iterator<Item = (&BufferSnapshot, Range<BufferOffset>, ExcerptId)> {
3816        ranges.flat_map(|range| {
3817            self.range_to_buffer_ranges((Bound::Included(range.start), Bound::Included(range.end)))
3818                .into_iter()
3819        })
3820    }
3821
3822    pub fn range_to_buffer_ranges<R, T>(
3823        &self,
3824        range: R,
3825    ) -> Vec<(&BufferSnapshot, Range<BufferOffset>, ExcerptId)>
3826    where
3827        R: RangeBounds<T>,
3828        T: ToOffset,
3829    {
3830        self.range_to_buffer_ranges_with_context(range)
3831            .into_iter()
3832            .map(|(buffer, range, id, _context)| (buffer, range, id))
3833            .collect()
3834    }
3835
3836    pub fn range_to_buffer_ranges_with_context<R, T>(
3837        &self,
3838        range: R,
3839    ) -> Vec<(
3840        &BufferSnapshot,
3841        Range<BufferOffset>,
3842        ExcerptId,
3843        Range<text::Anchor>,
3844    )>
3845    where
3846        R: RangeBounds<T>,
3847        T: ToOffset,
3848    {
3849        let start = match range.start_bound() {
3850            Bound::Included(start) => start.to_offset(self),
3851            Bound::Excluded(_) => panic!("excluded start bound not supported"),
3852            Bound::Unbounded => MultiBufferOffset::ZERO,
3853        };
3854        let end_bound = match range.end_bound() {
3855            Bound::Included(end) => Bound::Included(end.to_offset(self)),
3856            Bound::Excluded(end) => Bound::Excluded(end.to_offset(self)),
3857            Bound::Unbounded => Bound::Unbounded,
3858        };
3859        let bounds = (Bound::Included(start), end_bound);
3860
3861        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
3862        cursor.seek(&start);
3863
3864        let mut result: Vec<(
3865            &BufferSnapshot,
3866            Range<BufferOffset>,
3867            ExcerptId,
3868            Range<text::Anchor>,
3869        )> = Vec::new();
3870        while let Some(region) = cursor.region() {
3871            let dominated_by_end_bound = match end_bound {
3872                Bound::Included(end) => region.range.start > end,
3873                Bound::Excluded(end) => region.range.start >= end,
3874                Bound::Unbounded => false,
3875            };
3876            if dominated_by_end_bound {
3877                break;
3878            }
3879            if region.is_main_buffer {
3880                let start_overshoot = start.saturating_sub(region.range.start);
3881                let end_offset = match end_bound {
3882                    Bound::Included(end) | Bound::Excluded(end) => end,
3883                    Bound::Unbounded => region.range.end,
3884                };
3885                let end_overshoot = end_offset.saturating_sub(region.range.start);
3886                let start = region
3887                    .buffer_range
3888                    .end
3889                    .min(region.buffer_range.start + start_overshoot);
3890                let end = region
3891                    .buffer_range
3892                    .end
3893                    .min(region.buffer_range.start + end_overshoot);
3894                let context = region.excerpt.range.context.clone();
3895                if let Some(prev) = result.last_mut().filter(|(_, prev_range, excerpt_id, _)| {
3896                    *excerpt_id == region.excerpt.id && prev_range.end == start
3897                }) {
3898                    prev.1.end = end;
3899                } else {
3900                    result.push((region.buffer, start..end, region.excerpt.id, context));
3901                }
3902            }
3903            cursor.next();
3904        }
3905
3906        if let Some(excerpt) = cursor.excerpt() {
3907            let dominated_by_prev_excerpt =
3908                result.last().is_some_and(|(_, _, id, _)| *id == excerpt.id);
3909            if !dominated_by_prev_excerpt && excerpt.text_summary.len == 0 {
3910                let excerpt_position = self.len();
3911                if bounds.contains(&excerpt_position) {
3912                    let buffer_offset =
3913                        BufferOffset(excerpt.range.context.start.to_offset(&excerpt.buffer));
3914                    let context = excerpt.range.context.clone();
3915                    result.push((
3916                        &excerpt.buffer,
3917                        buffer_offset..buffer_offset,
3918                        excerpt.id,
3919                        context,
3920                    ));
3921                }
3922            }
3923        }
3924
3925        result
3926    }
3927
3928    pub fn range_to_buffer_ranges_with_deleted_hunks<T: ToOffset>(
3929        &self,
3930        range: Range<T>,
3931    ) -> impl Iterator<
3932        Item = (
3933            &BufferSnapshot,
3934            Range<BufferOffset>,
3935            ExcerptId,
3936            Option<Anchor>,
3937        ),
3938    > + '_ {
3939        let start = range.start.to_offset(self);
3940        let end = range.end.to_offset(self);
3941
3942        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
3943        cursor.seek(&start);
3944
3945        std::iter::from_fn(move || {
3946            let region = cursor.region()?;
3947            if region.range.start > end {
3948                return None;
3949            }
3950            let start_overshoot = start.saturating_sub(region.range.start);
3951            let end_overshoot = end.saturating_sub(region.range.start);
3952            let start = region
3953                .buffer_range
3954                .end
3955                .min(region.buffer_range.start + start_overshoot);
3956            let end = region
3957                .buffer_range
3958                .end
3959                .min(region.buffer_range.start + end_overshoot);
3960
3961            let region_excerpt_id = region.excerpt.id;
3962            let deleted_hunk_anchor = if region.is_main_buffer {
3963                None
3964            } else {
3965                Some(self.anchor_before(region.range.start))
3966            };
3967            let result = (
3968                region.buffer,
3969                start..end,
3970                region_excerpt_id,
3971                deleted_hunk_anchor,
3972            );
3973            cursor.next();
3974            Some(result)
3975        })
3976    }
3977
3978    /// Retrieves buffer metadata for the given range, and converts it into multi-buffer
3979    /// coordinates.
3980    ///
3981    /// The given callback will be called for every excerpt intersecting the given range. It will
3982    /// be passed the excerpt's buffer and the buffer range that the input range intersects.
3983    /// The callback should return an iterator of metadata items from that buffer, each paired
3984    /// with a buffer range.
3985    ///
3986    /// The returned iterator yields each of these metadata items, paired with its range in
3987    /// multi-buffer coordinates.
3988    fn lift_buffer_metadata<'a, MBD, M, I>(
3989        &'a self,
3990        query_range: Range<MBD>,
3991        get_buffer_metadata: impl 'a + Fn(&'a BufferSnapshot, Range<MBD::TextDimension>) -> Option<I>,
3992    ) -> impl Iterator<Item = (Range<MBD>, M, &'a Excerpt)> + 'a
3993    where
3994        I: Iterator<Item = (Range<MBD::TextDimension>, M)> + 'a,
3995        MBD: MultiBufferDimension
3996            + Ord
3997            + Sub<Output = MBD::TextDimension>
3998            + ops::Add<MBD::TextDimension, Output = MBD>
3999            + ops::AddAssign<MBD::TextDimension>,
4000        MBD::TextDimension: Sub<Output = MBD::TextDimension>
4001            + ops::Add<Output = MBD::TextDimension>
4002            + AddAssign<MBD::TextDimension>
4003            + Ord,
4004    {
4005        let mut current_excerpt_metadata: Option<(ExcerptId, I)> = None;
4006        let mut cursor = self.cursor::<MBD, MBD::TextDimension>();
4007
4008        // Find the excerpt and buffer offset where the given range ends.
4009        cursor.seek(&query_range.end);
4010        let mut range_end = None;
4011        while let Some(region) = cursor.region() {
4012            if region.is_main_buffer {
4013                let mut buffer_end = region.buffer_range.start;
4014                let overshoot = if query_range.end > region.range.start {
4015                    query_range.end - region.range.start
4016                } else {
4017                    <MBD::TextDimension>::default()
4018                };
4019                buffer_end = buffer_end + overshoot;
4020                range_end = Some((region.excerpt.id, buffer_end));
4021                break;
4022            }
4023            cursor.next();
4024        }
4025
4026        cursor.seek(&query_range.start);
4027
4028        if let Some(region) = cursor.region().filter(|region| !region.is_main_buffer)
4029            && region.range.start > MBD::default()
4030        {
4031            cursor.prev()
4032        } else if let Some(region) = cursor.region()
4033            && region.is_main_buffer
4034            && region.diff_hunk_status.is_some()
4035        {
4036            cursor.prev();
4037            if cursor.region().is_none_or(|region| region.is_main_buffer) {
4038                cursor.next();
4039            }
4040        }
4041
4042        iter::from_fn(move || {
4043            loop {
4044                let excerpt = cursor.excerpt()?;
4045
4046                // If we have already retrieved metadata for this excerpt, continue to use it.
4047                let metadata_iter = if let Some((_, metadata)) = current_excerpt_metadata
4048                    .as_mut()
4049                    .filter(|(excerpt_id, _)| *excerpt_id == excerpt.id)
4050                {
4051                    Some(metadata)
4052                }
4053                // Otherwise, compute the intersection of the input range with the excerpt's range,
4054                // and retrieve the metadata for the resulting range.
4055                else {
4056                    let region = cursor.region()?;
4057                    let mut buffer_start;
4058                    if region.is_main_buffer {
4059                        buffer_start = region.buffer_range.start;
4060                        if query_range.start > region.range.start {
4061                            let overshoot = query_range.start - region.range.start;
4062                            buffer_start = buffer_start + overshoot;
4063                        }
4064                        buffer_start = buffer_start.min(region.buffer_range.end);
4065                    } else {
4066                        buffer_start = cursor.main_buffer_position()?;
4067                    };
4068                    let mut buffer_end = excerpt
4069                        .range
4070                        .context
4071                        .end
4072                        .summary::<MBD::TextDimension>(&excerpt.buffer);
4073                    if let Some((end_excerpt_id, end_buffer_offset)) = range_end
4074                        && excerpt.id == end_excerpt_id
4075                    {
4076                        buffer_end = buffer_end.min(end_buffer_offset);
4077                    }
4078
4079                    get_buffer_metadata(&excerpt.buffer, buffer_start..buffer_end).map(|iterator| {
4080                        &mut current_excerpt_metadata.insert((excerpt.id, iterator)).1
4081                    })
4082                };
4083
4084                // Visit each metadata item.
4085                if let Some((metadata_buffer_range, metadata)) =
4086                    metadata_iter.and_then(Iterator::next)
4087                {
4088                    // Find the multibuffer regions that contain the start and end of
4089                    // the metadata item's range.
4090                    if metadata_buffer_range.start > <MBD::TextDimension>::default() {
4091                        while let Some(region) = cursor.region() {
4092                            if (region.is_main_buffer
4093                                && (region.buffer_range.end >= metadata_buffer_range.start
4094                                    || cursor.is_at_end_of_excerpt()))
4095                                || (!region.is_main_buffer
4096                                    && region.buffer_range.start == metadata_buffer_range.start)
4097                            {
4098                                break;
4099                            }
4100                            cursor.next();
4101                        }
4102                    }
4103                    let start_region = cursor.region()?.clone();
4104                    while let Some(region) = cursor.region() {
4105                        if region.is_main_buffer
4106                            && (region.buffer_range.end > metadata_buffer_range.end
4107                                || cursor.is_at_end_of_excerpt())
4108                        {
4109                            break;
4110                        }
4111                        cursor.next();
4112                    }
4113                    let end_region = cursor.region();
4114
4115                    // Convert the metadata item's range into multibuffer coordinates.
4116                    let mut start_position = start_region.range.start;
4117                    let region_buffer_start = start_region.buffer_range.start;
4118                    if start_region.is_main_buffer
4119                        && metadata_buffer_range.start > region_buffer_start
4120                    {
4121                        start_position =
4122                            start_position + (metadata_buffer_range.start - region_buffer_start);
4123                        start_position = start_position.min(start_region.range.end);
4124                    }
4125
4126                    let mut end_position = self.max_position();
4127                    if let Some(end_region) = &end_region {
4128                        end_position = end_region.range.start;
4129                        debug_assert!(end_region.is_main_buffer);
4130                        let region_buffer_start = end_region.buffer_range.start;
4131                        if metadata_buffer_range.end > region_buffer_start {
4132                            end_position =
4133                                end_position + (metadata_buffer_range.end - region_buffer_start);
4134                        }
4135                        end_position = end_position.min(end_region.range.end);
4136                    }
4137
4138                    if start_position <= query_range.end && end_position >= query_range.start {
4139                        return Some((start_position..end_position, metadata, excerpt));
4140                    }
4141                }
4142                // When there are no more metadata items for this excerpt, move to the next excerpt.
4143                else {
4144                    current_excerpt_metadata.take();
4145                    if let Some((end_excerpt_id, _)) = range_end
4146                        && excerpt.id == end_excerpt_id
4147                    {
4148                        return None;
4149                    }
4150                    cursor.next_excerpt_forwards();
4151                }
4152            }
4153        })
4154    }
4155
4156    pub fn diff_hunk_before<T: ToOffset>(&self, position: T) -> Option<MultiBufferRow> {
4157        let offset = position.to_offset(self);
4158
4159        let mut cursor = self
4160            .cursor::<DimensionPair<MultiBufferOffset, Point>, DimensionPair<BufferOffset, Point>>(
4161            );
4162        cursor.seek(&DimensionPair {
4163            key: offset,
4164            value: None,
4165        });
4166        cursor.seek_to_start_of_current_excerpt();
4167        let excerpt = cursor.excerpt()?;
4168
4169        let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
4170        let excerpt_end = excerpt.range.context.end.to_offset(&excerpt.buffer);
4171        let current_position = self
4172            .anchor_before(offset)
4173            .text_anchor
4174            .to_offset(&excerpt.buffer);
4175
4176        if let Some(diff) = self.diffs.get(&excerpt.buffer_id) {
4177            if let Some(main_buffer) = &diff.main_buffer {
4178                for hunk in diff
4179                    .hunks_intersecting_base_text_range_rev(excerpt_start..excerpt_end, main_buffer)
4180                {
4181                    if hunk.diff_base_byte_range.end >= current_position {
4182                        continue;
4183                    }
4184                    let hunk_start = excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start);
4185                    let start = Anchor::text(excerpt.id, hunk_start).to_point(self);
4186                    return Some(MultiBufferRow(start.row));
4187                }
4188            } else {
4189                let excerpt_end = excerpt
4190                    .buffer
4191                    .anchor_before(excerpt_end.min(current_position));
4192                for hunk in diff.hunks_intersecting_range_rev(
4193                    excerpt.range.context.start..excerpt_end,
4194                    &excerpt.buffer,
4195                ) {
4196                    let hunk_end = hunk.buffer_range.end.to_offset(&excerpt.buffer);
4197                    if hunk_end >= current_position {
4198                        continue;
4199                    }
4200                    let start = Anchor::text(excerpt.id, hunk.buffer_range.start).to_point(self);
4201                    return Some(MultiBufferRow(start.row));
4202                }
4203            }
4204        }
4205
4206        loop {
4207            cursor.prev_excerpt();
4208            let excerpt = cursor.excerpt()?;
4209
4210            let Some(diff) = self.diffs.get(&excerpt.buffer_id) else {
4211                continue;
4212            };
4213            if let Some(main_buffer) = &diff.main_buffer {
4214                let Some(hunk) = diff
4215                    .hunks_intersecting_base_text_range_rev(
4216                        excerpt.range.context.to_offset(&excerpt.buffer),
4217                        main_buffer,
4218                    )
4219                    .next()
4220                else {
4221                    continue;
4222                };
4223                let hunk_start = excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start);
4224                let start = Anchor::text(excerpt.id, hunk_start).to_point(self);
4225                return Some(MultiBufferRow(start.row));
4226            } else {
4227                let Some(hunk) = diff
4228                    .hunks_intersecting_range_rev(excerpt.range.context.clone(), &excerpt.buffer)
4229                    .next()
4230                else {
4231                    continue;
4232                };
4233                let start = Anchor::text(excerpt.id, hunk.buffer_range.start).to_point(self);
4234                return Some(MultiBufferRow(start.row));
4235            }
4236        }
4237    }
4238
4239    pub fn has_diff_hunks(&self) -> bool {
4240        self.diffs.values().any(|diff| !diff.is_empty())
4241    }
4242
4243    pub fn is_inside_word<T: ToOffset>(
4244        &self,
4245        position: T,
4246        scope_context: Option<CharScopeContext>,
4247    ) -> bool {
4248        let position = position.to_offset(self);
4249        let classifier = self
4250            .char_classifier_at(position)
4251            .scope_context(scope_context);
4252        let next_char_kind = self.chars_at(position).next().map(|c| classifier.kind(c));
4253        let prev_char_kind = self
4254            .reversed_chars_at(position)
4255            .next()
4256            .map(|c| classifier.kind(c));
4257        prev_char_kind.zip(next_char_kind) == Some((CharKind::Word, CharKind::Word))
4258    }
4259
4260    pub fn surrounding_word<T: ToOffset>(
4261        &self,
4262        start: T,
4263        scope_context: Option<CharScopeContext>,
4264    ) -> (Range<MultiBufferOffset>, Option<CharKind>) {
4265        let mut start = start.to_offset(self);
4266        let mut end = start;
4267        let mut next_chars = self.chars_at(start).peekable();
4268        let mut prev_chars = self.reversed_chars_at(start).peekable();
4269
4270        let classifier = self.char_classifier_at(start).scope_context(scope_context);
4271
4272        let word_kind = cmp::max(
4273            prev_chars.peek().copied().map(|c| classifier.kind(c)),
4274            next_chars.peek().copied().map(|c| classifier.kind(c)),
4275        );
4276
4277        for ch in prev_chars {
4278            if Some(classifier.kind(ch)) == word_kind && ch != '\n' {
4279                start -= ch.len_utf8();
4280            } else {
4281                break;
4282            }
4283        }
4284
4285        for ch in next_chars {
4286            if Some(classifier.kind(ch)) == word_kind && ch != '\n' {
4287                end += ch.len_utf8();
4288            } else {
4289                break;
4290            }
4291        }
4292
4293        (start..end, word_kind)
4294    }
4295
4296    pub fn char_kind_before<T: ToOffset>(
4297        &self,
4298        start: T,
4299        scope_context: Option<CharScopeContext>,
4300    ) -> Option<CharKind> {
4301        let start = start.to_offset(self);
4302        let classifier = self.char_classifier_at(start).scope_context(scope_context);
4303        self.reversed_chars_at(start)
4304            .next()
4305            .map(|ch| classifier.kind(ch))
4306    }
4307
4308    pub fn is_singleton(&self) -> bool {
4309        self.singleton
4310    }
4311
4312    pub fn as_singleton(&self) -> Option<(ExcerptId, BufferId, &BufferSnapshot)> {
4313        if self.singleton {
4314            self.excerpts
4315                .iter()
4316                .next()
4317                .map(|e| (e.id, e.buffer_id, &*e.buffer))
4318        } else {
4319            None
4320        }
4321    }
4322
4323    pub fn len(&self) -> MultiBufferOffset {
4324        self.diff_transforms.summary().output.len
4325    }
4326
4327    pub fn max_position<MBD: MultiBufferDimension>(&self) -> MBD {
4328        MBD::from_summary(&self.text_summary())
4329    }
4330
4331    pub fn is_empty(&self) -> bool {
4332        self.diff_transforms.summary().output.len == MultiBufferOffset(0)
4333    }
4334
4335    pub fn widest_line_number(&self) -> u32 {
4336        // widest_line_number is 0-based, so 1 is added to get the displayed line number.
4337        self.excerpts.summary().widest_line_number + 1
4338    }
4339
4340    pub fn bytes_in_range<T: ToOffset>(&self, range: Range<T>) -> MultiBufferBytes<'_> {
4341        let range = range.start.to_offset(self)..range.end.to_offset(self);
4342        let mut excerpts = self.cursor::<MultiBufferOffset, BufferOffset>();
4343        excerpts.seek(&range.start);
4344
4345        let mut chunk;
4346        let mut has_trailing_newline;
4347        let excerpt_bytes;
4348        if let Some(region) = excerpts.region() {
4349            let mut bytes = region.buffer.bytes_in_range(
4350                region.buffer_range.start + (range.start - region.range.start)
4351                    ..(region.buffer_range.start + (range.end - region.range.start))
4352                        .min(region.buffer_range.end),
4353            );
4354            chunk = bytes.next().unwrap_or(&[][..]);
4355            excerpt_bytes = Some(bytes);
4356            has_trailing_newline = region.has_trailing_newline && range.end >= region.range.end;
4357            if chunk.is_empty() && has_trailing_newline {
4358                chunk = b"\n";
4359                has_trailing_newline = false;
4360            }
4361        } else {
4362            chunk = &[][..];
4363            excerpt_bytes = None;
4364            has_trailing_newline = false;
4365        };
4366
4367        MultiBufferBytes {
4368            range,
4369            cursor: excerpts,
4370            excerpt_bytes,
4371            has_trailing_newline,
4372            chunk,
4373        }
4374    }
4375
4376    pub fn reversed_bytes_in_range<T: ToOffset>(
4377        &self,
4378        range: Range<T>,
4379    ) -> ReversedMultiBufferBytes<'_> {
4380        let range = range.start.to_offset(self)..range.end.to_offset(self);
4381        let mut chunks = self.reversed_chunks_in_range(range.clone());
4382        let chunk = chunks.next().map_or(&[][..], |c| c.as_bytes());
4383        ReversedMultiBufferBytes {
4384            range,
4385            chunks,
4386            chunk,
4387        }
4388    }
4389
4390    pub fn row_infos(&self, start_row: MultiBufferRow) -> MultiBufferRows<'_> {
4391        let mut cursor = self.cursor::<Point, Point>();
4392        cursor.seek(&Point::new(start_row.0, 0));
4393        let mut result = MultiBufferRows {
4394            point: Point::new(0, 0),
4395            is_empty: self.excerpts.is_empty(),
4396            is_singleton: self.is_singleton(),
4397            cursor,
4398        };
4399        result.seek(start_row);
4400        result
4401    }
4402
4403    pub fn chunks<T: ToOffset>(
4404        &self,
4405        range: Range<T>,
4406        language_aware: bool,
4407    ) -> MultiBufferChunks<'_> {
4408        let mut chunks = MultiBufferChunks {
4409            excerpt_offset_range: ExcerptDimension(MultiBufferOffset::ZERO)
4410                ..ExcerptDimension(MultiBufferOffset::ZERO),
4411            range: MultiBufferOffset::ZERO..MultiBufferOffset::ZERO,
4412            excerpts: self.excerpts.cursor(()),
4413            diff_transforms: self.diff_transforms.cursor(()),
4414            diffs: &self.diffs,
4415            diff_base_chunks: None,
4416            excerpt_chunks: None,
4417            buffer_chunk: None,
4418            language_aware,
4419        };
4420        let range = range.start.to_offset(self)..range.end.to_offset(self);
4421        chunks.seek(range);
4422        chunks
4423    }
4424
4425    pub fn clip_offset(&self, offset: MultiBufferOffset, bias: Bias) -> MultiBufferOffset {
4426        self.clip_dimension(offset, bias, text::BufferSnapshot::clip_offset)
4427    }
4428
4429    pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
4430        self.clip_dimension(point, bias, text::BufferSnapshot::clip_point)
4431    }
4432
4433    pub fn clip_offset_utf16(
4434        &self,
4435        offset: MultiBufferOffsetUtf16,
4436        bias: Bias,
4437    ) -> MultiBufferOffsetUtf16 {
4438        self.clip_dimension(offset, bias, text::BufferSnapshot::clip_offset_utf16)
4439    }
4440
4441    pub fn clip_point_utf16(&self, point: Unclipped<PointUtf16>, bias: Bias) -> PointUtf16 {
4442        self.clip_dimension(point.0, bias, |buffer, point, bias| {
4443            buffer.clip_point_utf16(Unclipped(point), bias)
4444        })
4445    }
4446
4447    pub fn offset_to_point(&self, offset: MultiBufferOffset) -> Point {
4448        self.convert_dimension(offset, text::BufferSnapshot::offset_to_point)
4449    }
4450
4451    pub fn offset_to_point_utf16(&self, offset: MultiBufferOffset) -> PointUtf16 {
4452        self.convert_dimension(offset, text::BufferSnapshot::offset_to_point_utf16)
4453    }
4454
4455    pub fn point_to_point_utf16(&self, point: Point) -> PointUtf16 {
4456        self.convert_dimension(point, text::BufferSnapshot::point_to_point_utf16)
4457    }
4458
4459    pub fn point_utf16_to_point(&self, point: PointUtf16) -> Point {
4460        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_point)
4461    }
4462
4463    #[instrument(skip_all)]
4464    pub fn point_to_offset(&self, point: Point) -> MultiBufferOffset {
4465        self.convert_dimension(point, text::BufferSnapshot::point_to_offset)
4466    }
4467
4468    pub fn point_to_offset_utf16(&self, point: Point) -> MultiBufferOffsetUtf16 {
4469        self.convert_dimension(point, text::BufferSnapshot::point_to_offset_utf16)
4470    }
4471
4472    pub fn offset_utf16_to_offset(&self, offset: MultiBufferOffsetUtf16) -> MultiBufferOffset {
4473        self.convert_dimension(offset, text::BufferSnapshot::offset_utf16_to_offset)
4474    }
4475
4476    pub fn offset_to_offset_utf16(&self, offset: MultiBufferOffset) -> MultiBufferOffsetUtf16 {
4477        self.convert_dimension(offset, text::BufferSnapshot::offset_to_offset_utf16)
4478    }
4479
4480    pub fn point_utf16_to_offset(&self, point: PointUtf16) -> MultiBufferOffset {
4481        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_offset)
4482    }
4483
4484    pub fn point_utf16_to_offset_utf16(&self, point: PointUtf16) -> MultiBufferOffsetUtf16 {
4485        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_offset_utf16)
4486    }
4487
4488    fn clip_dimension<MBD, BD>(
4489        &self,
4490        position: MBD,
4491        bias: Bias,
4492        clip_buffer_position: fn(&text::BufferSnapshot, BD, Bias) -> BD,
4493    ) -> MBD
4494    where
4495        MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
4496        BD: TextDimension + Sub<Output = <MBD as Sub>::Output> + AddAssign<<MBD as Sub>::Output>,
4497    {
4498        let mut cursor = self.cursor::<MBD, BD>();
4499        cursor.seek(&position);
4500        if let Some(region) = cursor.region() {
4501            if position >= region.range.end {
4502                return region.range.end;
4503            }
4504            let overshoot = position - region.range.start;
4505            let mut buffer_position = region.buffer_range.start;
4506            buffer_position += overshoot;
4507            let clipped_buffer_position =
4508                clip_buffer_position(region.buffer, buffer_position, bias);
4509            let mut position = region.range.start;
4510            position += clipped_buffer_position - region.buffer_range.start;
4511            position
4512        } else {
4513            self.max_position()
4514        }
4515    }
4516
4517    #[instrument(skip_all)]
4518    fn convert_dimension<MBR1, MBR2, BR1, BR2>(
4519        &self,
4520        key: MBR1,
4521        convert_buffer_dimension: fn(&text::BufferSnapshot, BR1) -> BR2,
4522    ) -> MBR2
4523    where
4524        MBR1: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBR1 as Sub>::Output>,
4525        BR1: TextDimension + Sub<Output = <MBR1 as Sub>::Output> + AddAssign<<MBR1 as Sub>::Output>,
4526        MBR2: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBR2 as Sub>::Output>,
4527        BR2: TextDimension + Sub<Output = <MBR2 as Sub>::Output> + AddAssign<<MBR2 as Sub>::Output>,
4528    {
4529        let mut cursor = self.cursor::<DimensionPair<MBR1, MBR2>, DimensionPair<BR1, BR2>>();
4530        cursor.seek(&DimensionPair { key, value: None });
4531        if let Some(region) = cursor.region() {
4532            if key >= region.range.end.key {
4533                return region.range.end.value.unwrap();
4534            }
4535            let start_key = region.range.start.key;
4536            let start_value = region.range.start.value.unwrap();
4537            let buffer_start_key = region.buffer_range.start.key;
4538            let buffer_start_value = region.buffer_range.start.value.unwrap();
4539            let mut buffer_key = buffer_start_key;
4540            buffer_key += key - start_key;
4541            let buffer_value = convert_buffer_dimension(region.buffer, buffer_key);
4542            let mut result = start_value;
4543            result += buffer_value - buffer_start_value;
4544            result
4545        } else {
4546            self.max_position()
4547        }
4548    }
4549
4550    pub fn point_to_buffer_offset<T: ToOffset>(
4551        &self,
4552        point: T,
4553    ) -> Option<(&BufferSnapshot, BufferOffset)> {
4554        let offset = point.to_offset(self);
4555        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
4556        cursor.seek(&offset);
4557        let region = cursor.region()?;
4558        let overshoot = offset - region.range.start;
4559        let buffer_offset = region.buffer_range.start + overshoot;
4560        if buffer_offset == BufferOffset(region.buffer.len() + 1)
4561            && region.has_trailing_newline
4562            && !region.is_main_buffer
4563        {
4564            let main_buffer_position = cursor.main_buffer_position()?;
4565            let buffer_snapshot = &cursor.excerpt()?.buffer;
4566            return Some((buffer_snapshot, main_buffer_position));
4567        } else if buffer_offset > BufferOffset(region.buffer.len()) {
4568            return None;
4569        }
4570        Some((region.buffer, buffer_offset))
4571    }
4572
4573    pub fn point_to_buffer_point(&self, point: Point) -> Option<(&BufferSnapshot, Point)> {
4574        let mut cursor = self.cursor::<Point, Point>();
4575        cursor.seek(&point);
4576        let region = cursor.region()?;
4577        let overshoot = point - region.range.start;
4578        let buffer_point = region.buffer_range.start + overshoot;
4579        let excerpt = cursor.excerpt()?;
4580        if buffer_point == region.buffer.max_point() + Point::new(1, 0)
4581            && region.has_trailing_newline
4582            && !region.is_main_buffer
4583        {
4584            return Some((&excerpt.buffer, cursor.main_buffer_position()?));
4585        } else if buffer_point > region.buffer.max_point() {
4586            return None;
4587        }
4588        Some((region.buffer, buffer_point))
4589    }
4590
4591    pub fn suggested_indents(
4592        &self,
4593        rows: impl IntoIterator<Item = u32>,
4594        cx: &App,
4595    ) -> BTreeMap<MultiBufferRow, IndentSize> {
4596        let mut result = BTreeMap::new();
4597        self.suggested_indents_callback(
4598            rows,
4599            &mut |row, indent| {
4600                result.insert(row, indent);
4601                ControlFlow::Continue(())
4602            },
4603            cx,
4604        );
4605        result
4606    }
4607
4608    // move this to be a generator once those are a thing
4609    pub fn suggested_indents_callback(
4610        &self,
4611        rows: impl IntoIterator<Item = u32>,
4612        cb: &mut dyn FnMut(MultiBufferRow, IndentSize) -> ControlFlow<()>,
4613        cx: &App,
4614    ) {
4615        let mut rows_for_excerpt = Vec::new();
4616        let mut cursor = self.cursor::<Point, Point>();
4617        let mut rows = rows.into_iter().peekable();
4618        let mut prev_row = u32::MAX;
4619        let mut prev_language_indent_size = IndentSize::default();
4620
4621        while let Some(row) = rows.next() {
4622            cursor.seek(&Point::new(row, 0));
4623            let Some(region) = cursor.region() else {
4624                continue;
4625            };
4626
4627            // Retrieve the language and indent size once for each disjoint region being indented.
4628            let single_indent_size = if row.saturating_sub(1) == prev_row {
4629                prev_language_indent_size
4630            } else {
4631                region
4632                    .buffer
4633                    .language_indent_size_at(Point::new(row, 0), cx)
4634            };
4635            prev_language_indent_size = single_indent_size;
4636            prev_row = row;
4637
4638            let start_buffer_row = region.buffer_range.start.row;
4639            let start_multibuffer_row = region.range.start.row;
4640            let end_multibuffer_row = region.range.end.row;
4641
4642            rows_for_excerpt.push(row);
4643            while let Some(next_row) = rows.peek().copied() {
4644                if end_multibuffer_row > next_row {
4645                    rows_for_excerpt.push(next_row);
4646                    rows.next();
4647                } else {
4648                    break;
4649                }
4650            }
4651
4652            let buffer_rows = rows_for_excerpt
4653                .drain(..)
4654                .map(|row| start_buffer_row + row - start_multibuffer_row);
4655            let buffer_indents = region
4656                .buffer
4657                .suggested_indents(buffer_rows, single_indent_size);
4658            for (row, indent) in buffer_indents {
4659                if cb(
4660                    MultiBufferRow(start_multibuffer_row + row - start_buffer_row),
4661                    indent,
4662                )
4663                .is_break()
4664                {
4665                    return;
4666                }
4667            }
4668        }
4669    }
4670
4671    pub fn indent_size_for_line(&self, row: MultiBufferRow) -> IndentSize {
4672        if let Some((buffer, range)) = self.buffer_line_for_row(row) {
4673            let mut size = buffer.indent_size_for_line(range.start.row);
4674            size.len = size
4675                .len
4676                .min(range.end.column)
4677                .saturating_sub(range.start.column);
4678            size
4679        } else {
4680            IndentSize::spaces(0)
4681        }
4682    }
4683
4684    pub fn line_indent_for_row(&self, row: MultiBufferRow) -> LineIndent {
4685        if let Some((buffer, range)) = self.buffer_line_for_row(row) {
4686            LineIndent::from_iter(buffer.text_for_range(range).flat_map(|s| s.chars()))
4687        } else {
4688            LineIndent::spaces(0)
4689        }
4690    }
4691
4692    pub fn indent_and_comment_for_line(&self, row: MultiBufferRow, cx: &App) -> String {
4693        let mut indent = self.indent_size_for_line(row).chars().collect::<String>();
4694
4695        if self.language_settings(cx).extend_comment_on_newline
4696            && let Some(language_scope) = self.language_scope_at(Point::new(row.0, 0))
4697        {
4698            let delimiters = language_scope.line_comment_prefixes();
4699            for delimiter in delimiters {
4700                if *self
4701                    .chars_at(Point::new(row.0, indent.len() as u32))
4702                    .take(delimiter.chars().count())
4703                    .collect::<String>()
4704                    .as_str()
4705                    == **delimiter
4706                {
4707                    indent.push_str(delimiter);
4708                    break;
4709                }
4710            }
4711        }
4712
4713        indent
4714    }
4715
4716    pub fn is_line_whitespace_upto<T>(&self, position: T) -> bool
4717    where
4718        T: ToOffset,
4719    {
4720        for char in self.reversed_chars_at(position) {
4721            if !char.is_whitespace() {
4722                return false;
4723            }
4724            if char == '\n' {
4725                return true;
4726            }
4727        }
4728        true
4729    }
4730
4731    pub fn prev_non_blank_row(&self, mut row: MultiBufferRow) -> Option<MultiBufferRow> {
4732        while row.0 > 0 {
4733            row.0 -= 1;
4734            if !self.is_line_blank(row) {
4735                return Some(row);
4736            }
4737        }
4738        None
4739    }
4740
4741    pub fn line_len(&self, row: MultiBufferRow) -> u32 {
4742        if let Some((_, range)) = self.buffer_line_for_row(row) {
4743            range.end.column - range.start.column
4744        } else {
4745            0
4746        }
4747    }
4748
4749    pub fn buffer_line_for_row(
4750        &self,
4751        row: MultiBufferRow,
4752    ) -> Option<(&BufferSnapshot, Range<Point>)> {
4753        let mut cursor = self.cursor::<Point, Point>();
4754        let point = Point::new(row.0, 0);
4755        cursor.seek(&point);
4756        let region = cursor.region()?;
4757        let overshoot = point.min(region.range.end) - region.range.start;
4758        let buffer_point = region.buffer_range.start + overshoot;
4759        if buffer_point.row > region.buffer_range.end.row {
4760            return None;
4761        }
4762        let line_start = Point::new(buffer_point.row, 0).max(region.buffer_range.start);
4763        let line_end = Point::new(buffer_point.row, region.buffer.line_len(buffer_point.row))
4764            .min(region.buffer_range.end);
4765        Some((region.buffer, line_start..line_end))
4766    }
4767
4768    pub fn max_point(&self) -> Point {
4769        self.text_summary().lines
4770    }
4771
4772    pub fn max_row(&self) -> MultiBufferRow {
4773        MultiBufferRow(self.text_summary().lines.row)
4774    }
4775
4776    pub fn text_summary(&self) -> MBTextSummary {
4777        self.diff_transforms.summary().output
4778    }
4779
4780    pub fn text_summary_for_range<MBD, O>(&self, range: Range<O>) -> MBD
4781    where
4782        MBD: MultiBufferDimension + AddAssign,
4783        O: ToOffset,
4784    {
4785        let range = range.start.to_offset(self)..range.end.to_offset(self);
4786        let mut cursor = self
4787            .diff_transforms
4788            .cursor::<Dimensions<MultiBufferOffset, ExcerptOffset>>(());
4789        cursor.seek(&range.start, Bias::Right);
4790
4791        let Some(first_transform) = cursor.item() else {
4792            return MBD::from_summary(&MBTextSummary::default());
4793        };
4794
4795        let diff_transform_start = cursor.start().0;
4796        let diff_transform_end = cursor.end().0;
4797        let diff_start = range.start;
4798        let start_overshoot = diff_start - diff_transform_start;
4799        let end_overshoot = std::cmp::min(range.end, diff_transform_end) - diff_transform_start;
4800
4801        let mut result = match first_transform {
4802            DiffTransform::BufferContent { .. } => {
4803                let excerpt_start = cursor.start().1 + start_overshoot;
4804                let excerpt_end = cursor.start().1 + end_overshoot;
4805                self.text_summary_for_excerpt_offset_range(excerpt_start..excerpt_end)
4806            }
4807            DiffTransform::DeletedHunk {
4808                buffer_id,
4809                base_text_byte_range,
4810                has_trailing_newline,
4811                ..
4812            } => {
4813                let buffer_start = base_text_byte_range.start + start_overshoot;
4814                let mut buffer_end = base_text_byte_range.start + end_overshoot;
4815                let Some(base_text) = self.diffs.get(buffer_id).map(|diff| diff.base_text()) else {
4816                    panic!("{:?} is in non-existent deleted hunk", range.start)
4817                };
4818
4819                let include_trailing_newline =
4820                    *has_trailing_newline && range.end >= diff_transform_end;
4821                if include_trailing_newline {
4822                    buffer_end -= 1;
4823                }
4824
4825                let mut summary = base_text
4826                    .text_summary_for_range::<MBD::TextDimension, _>(buffer_start..buffer_end);
4827
4828                if include_trailing_newline {
4829                    summary.add_assign(&<MBD::TextDimension>::from_text_summary(
4830                        &TextSummary::newline(),
4831                    ))
4832                }
4833
4834                let mut result = MBD::default();
4835                result.add_text_dim(&summary);
4836                result
4837            }
4838        };
4839        if range.end < diff_transform_end {
4840            return result;
4841        }
4842
4843        cursor.next();
4844        result.add_mb_text_summary(
4845            &cursor
4846                .summary::<_, OutputDimension<_>>(&range.end, Bias::Right)
4847                .0,
4848        );
4849
4850        let Some(last_transform) = cursor.item() else {
4851            return result;
4852        };
4853
4854        let overshoot = range.end - cursor.start().0;
4855        let suffix = match last_transform {
4856            DiffTransform::BufferContent { .. } => {
4857                let end = cursor.start().1 + overshoot;
4858                self.text_summary_for_excerpt_offset_range::<MBD>(cursor.start().1..end)
4859            }
4860            DiffTransform::DeletedHunk {
4861                base_text_byte_range,
4862                buffer_id,
4863                has_trailing_newline,
4864                ..
4865            } => {
4866                let buffer_end = base_text_byte_range.start + overshoot;
4867                let Some(base_text) = self.diffs.get(buffer_id).map(|diff| diff.base_text()) else {
4868                    panic!("{:?} is in non-existent deleted hunk", range.end)
4869                };
4870
4871                let mut suffix = base_text.text_summary_for_range::<MBD::TextDimension, _>(
4872                    base_text_byte_range.start..buffer_end,
4873                );
4874                if *has_trailing_newline && buffer_end == base_text_byte_range.end + 1 {
4875                    suffix.add_assign(&<MBD::TextDimension>::from_text_summary(
4876                        &TextSummary::from("\n"),
4877                    ))
4878                }
4879
4880                let mut result = MBD::default();
4881                result.add_text_dim(&suffix);
4882                result
4883            }
4884        };
4885
4886        result += suffix;
4887        result
4888    }
4889
4890    fn text_summary_for_excerpt_offset_range<MBD>(&self, mut range: Range<ExcerptOffset>) -> MBD
4891    where
4892        MBD: MultiBufferDimension + AddAssign,
4893    {
4894        let mut summary = MBD::default();
4895        let mut cursor = self.excerpts.cursor::<ExcerptOffset>(());
4896        cursor.seek(&range.start, Bias::Right);
4897        if let Some(excerpt) = cursor.item() {
4898            let mut end_before_newline = cursor.end();
4899            if excerpt.has_trailing_newline {
4900                end_before_newline -= 1;
4901            }
4902
4903            let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
4904            let start_in_excerpt = excerpt_start + (range.start - *cursor.start());
4905            let end_in_excerpt =
4906                excerpt_start + (cmp::min(end_before_newline, range.end) - *cursor.start());
4907            summary.add_text_dim(
4908                &excerpt
4909                    .buffer
4910                    .text_summary_for_range::<MBD::TextDimension, _>(
4911                        start_in_excerpt..end_in_excerpt,
4912                    ),
4913            );
4914
4915            if range.end > end_before_newline {
4916                summary.add_mb_text_summary(&MBTextSummary::from(TextSummary::newline()));
4917            }
4918
4919            cursor.next();
4920        }
4921
4922        if range.end > *cursor.start() {
4923            summary += cursor
4924                .summary::<_, ExcerptDimension<MBD>>(&range.end, Bias::Right)
4925                .0;
4926            if let Some(excerpt) = cursor.item() {
4927                range.end = cmp::max(*cursor.start(), range.end);
4928
4929                let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
4930                let end_in_excerpt = excerpt_start + (range.end - *cursor.start());
4931                summary.add_text_dim(
4932                    &excerpt
4933                        .buffer
4934                        .text_summary_for_range::<MBD::TextDimension, _>(
4935                            excerpt_start..end_in_excerpt,
4936                        ),
4937                );
4938            }
4939        }
4940
4941        summary
4942    }
4943
4944    pub fn summary_for_anchor<MBD>(&self, anchor: &Anchor) -> MBD
4945    where
4946        MBD: MultiBufferDimension
4947            + Ord
4948            + Sub<Output = MBD::TextDimension>
4949            + Sub<MBD::TextDimension, Output = MBD>
4950            + AddAssign<MBD::TextDimension>
4951            + Add<MBD::TextDimension, Output = MBD>,
4952        MBD::TextDimension: Sub<Output = MBD::TextDimension> + Ord,
4953    {
4954        let excerpt_id = self.latest_excerpt_id(anchor.excerpt_id);
4955        let locator = self.excerpt_locator_for_id(excerpt_id);
4956        let (start, _, mut item) = self
4957            .excerpts
4958            .find::<ExcerptSummary, _>((), locator, Bias::Left);
4959        let mut start = MBD::from_summary(&start.text);
4960        if item.is_none() && excerpt_id == ExcerptId::max() {
4961            item = self.excerpts.last();
4962            if let Some(last_summary) = self.excerpts.last_summary() {
4963                start = start - <MBD::TextDimension>::from_text_summary(&last_summary.text.into());
4964            }
4965        }
4966
4967        let excerpt_start_position = ExcerptDimension(start);
4968        if self.diff_transforms.is_empty() {
4969            if let Some(excerpt) = item {
4970                if excerpt.id != excerpt_id && excerpt_id != ExcerptId::max() {
4971                    return excerpt_start_position.0;
4972                }
4973                let excerpt_buffer_start = excerpt
4974                    .range
4975                    .context
4976                    .start
4977                    .summary::<MBD::TextDimension>(&excerpt.buffer);
4978                let excerpt_buffer_end = excerpt
4979                    .range
4980                    .context
4981                    .end
4982                    .summary::<MBD::TextDimension>(&excerpt.buffer);
4983                let buffer_summary = anchor
4984                    .text_anchor
4985                    .summary::<MBD::TextDimension>(&excerpt.buffer);
4986                let summary = cmp::min(excerpt_buffer_end, buffer_summary);
4987                let mut position = excerpt_start_position;
4988                if summary > excerpt_buffer_start {
4989                    position += summary - excerpt_buffer_start;
4990                }
4991
4992                position.0
4993            } else {
4994                excerpt_start_position.0
4995            }
4996        } else {
4997            let mut diff_transforms_cursor = self
4998                .diff_transforms
4999                .cursor::<Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>>(());
5000            diff_transforms_cursor.next();
5001
5002            if let Some(excerpt) = item {
5003                if excerpt.id != excerpt_id && excerpt_id != ExcerptId::max() {
5004                    return self.resolve_summary_for_min_or_max_anchor(
5005                        &Anchor::min(),
5006                        excerpt_start_position,
5007                        &mut diff_transforms_cursor,
5008                    );
5009                }
5010                let excerpt_buffer_start = excerpt
5011                    .range
5012                    .context
5013                    .start
5014                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5015                let excerpt_buffer_end = excerpt
5016                    .range
5017                    .context
5018                    .end
5019                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5020                let buffer_summary = anchor
5021                    .text_anchor
5022                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5023                let summary = cmp::min(excerpt_buffer_end, buffer_summary);
5024                let mut position = excerpt_start_position;
5025                if summary > excerpt_buffer_start {
5026                    position += summary - excerpt_buffer_start;
5027                }
5028
5029                if diff_transforms_cursor.start().0 < position {
5030                    diff_transforms_cursor.seek_forward(&position, Bias::Left);
5031                }
5032                self.resolve_summary_for_anchor(
5033                    &anchor,
5034                    position,
5035                    &mut diff_transforms_cursor,
5036                    &excerpt.buffer,
5037                )
5038            } else {
5039                diff_transforms_cursor.seek_forward(&excerpt_start_position, Bias::Left);
5040                self.resolve_summary_for_min_or_max_anchor(
5041                    &Anchor::max(),
5042                    excerpt_start_position,
5043                    &mut diff_transforms_cursor,
5044                )
5045            }
5046        }
5047    }
5048
5049    /// Maps an anchor's excerpt-space position to its output-space position by
5050    /// walking the diff transforms. The cursor is shared across consecutive
5051    /// calls, so it may already be partway through the transform list.
5052    fn resolve_summary_for_anchor<MBD>(
5053        &self,
5054        anchor: &Anchor,
5055        excerpt_position: ExcerptDimension<MBD>,
5056        diff_transforms: &mut Cursor<
5057            DiffTransform,
5058            Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>,
5059        >,
5060        excerpt_buffer: &text::BufferSnapshot,
5061    ) -> MBD
5062    where
5063        MBD: MultiBufferDimension + Ord + Sub + AddAssign<<MBD as Sub>::Output>,
5064    {
5065        loop {
5066            let transform_end_position = diff_transforms.end().0;
5067            let item = diff_transforms.item();
5068            let at_transform_end = transform_end_position == excerpt_position && item.is_some();
5069
5070            // A right-biased anchor at a transform boundary belongs to the
5071            // *next* transform, so advance past the current one.
5072            if anchor.text_anchor.bias == Bias::Right && at_transform_end {
5073                diff_transforms.next();
5074                continue;
5075            }
5076
5077            let mut position = diff_transforms.start().1;
5078            match item {
5079                Some(DiffTransform::DeletedHunk {
5080                    buffer_id,
5081                    base_text_byte_range,
5082                    hunk_info,
5083                    ..
5084                }) => {
5085                    if let Some(diff_base_anchor) = &anchor.diff_base_anchor
5086                        && let Some(base_text) =
5087                            self.diffs.get(buffer_id).map(|diff| diff.base_text())
5088                        && diff_base_anchor.is_valid(&base_text)
5089                    {
5090                        // The anchor carries a diff-base position — resolve it
5091                        // to a location inside the deleted hunk.
5092                        let base_text_offset = diff_base_anchor.to_offset(base_text);
5093                        if base_text_offset >= base_text_byte_range.start
5094                            && base_text_offset <= base_text_byte_range.end
5095                        {
5096                            let position_in_hunk = base_text
5097                                .text_summary_for_range::<MBD::TextDimension, _>(
5098                                    base_text_byte_range.start..base_text_offset,
5099                                );
5100                            position.0.add_text_dim(&position_in_hunk);
5101                        } else if at_transform_end {
5102                            // diff_base offset falls outside this hunk's range;
5103                            // advance to see if the next transform is a better fit.
5104                            diff_transforms.next();
5105                            continue;
5106                        }
5107                    } else if at_transform_end
5108                        && anchor
5109                            .text_anchor
5110                            .cmp(&hunk_info.hunk_start_anchor, excerpt_buffer)
5111                            .is_gt()
5112                    {
5113                        // The anchor has no (valid) diff-base position, so it
5114                        // belongs in the buffer content, not in the deleted
5115                        // hunk. However, after an edit deletes the text between
5116                        // the hunk boundary and this anchor, both resolve to
5117                        // the same excerpt_position—landing us here on the
5118                        // DeletedHunk left behind by the shared cursor. Use the
5119                        // CRDT ordering to detect that the anchor is strictly
5120                        // *past* the hunk boundary and skip to the following
5121                        // BufferContent.
5122                        diff_transforms.next();
5123                        continue;
5124                    }
5125                }
5126                _ => {
5127                    // On a BufferContent (or no transform). If the anchor
5128                    // carries a diff_base_anchor it needs a DeletedHunk, so
5129                    // advance to find one.
5130                    if at_transform_end && anchor.diff_base_anchor.is_some() {
5131                        diff_transforms.next();
5132                        continue;
5133                    }
5134                    let overshoot = excerpt_position - diff_transforms.start().0;
5135                    position += overshoot;
5136                }
5137            }
5138
5139            return position.0;
5140        }
5141    }
5142
5143    /// Like `resolve_summary_for_anchor` but optimized for min/max anchors.
5144    fn resolve_summary_for_min_or_max_anchor<MBD>(
5145        &self,
5146        anchor: &Anchor,
5147        excerpt_position: ExcerptDimension<MBD>,
5148        diff_transforms: &mut Cursor<
5149            DiffTransform,
5150            Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>,
5151        >,
5152    ) -> MBD
5153    where
5154        MBD: MultiBufferDimension + Ord + Sub + AddAssign<<MBD as Sub>::Output>,
5155    {
5156        loop {
5157            let transform_end_position = diff_transforms.end().0;
5158            let item = diff_transforms.item();
5159            let at_transform_end = transform_end_position == excerpt_position && item.is_some();
5160
5161            // A right-biased anchor at a transform boundary belongs to the
5162            // *next* transform, so advance past the current one.
5163            if anchor.text_anchor.bias == Bias::Right && at_transform_end {
5164                diff_transforms.next();
5165                continue;
5166            }
5167
5168            let mut position = diff_transforms.start().1;
5169            if let Some(DiffTransform::BufferContent { .. }) | None = item {
5170                let overshoot = excerpt_position - diff_transforms.start().0;
5171                position += overshoot;
5172            }
5173
5174            return position.0;
5175        }
5176    }
5177
5178    fn excerpt_offset_for_anchor(&self, anchor: &Anchor) -> ExcerptOffset {
5179        let mut cursor = self
5180            .excerpts
5181            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
5182        let locator = self.excerpt_locator_for_id(anchor.excerpt_id);
5183
5184        cursor.seek(&Some(locator), Bias::Left);
5185        if cursor.item().is_none() && anchor.excerpt_id == ExcerptId::max() {
5186            cursor.prev();
5187        }
5188
5189        let mut position = cursor.start().1;
5190        if let Some(excerpt) = cursor.item()
5191            && (excerpt.id == anchor.excerpt_id || anchor.excerpt_id == ExcerptId::max())
5192        {
5193            let excerpt_buffer_start = excerpt
5194                .buffer
5195                .offset_for_anchor(&excerpt.range.context.start);
5196            let excerpt_buffer_end = excerpt.buffer.offset_for_anchor(&excerpt.range.context.end);
5197            let buffer_position = cmp::min(
5198                excerpt_buffer_end,
5199                excerpt.buffer.offset_for_anchor(&anchor.text_anchor),
5200            );
5201            if buffer_position > excerpt_buffer_start {
5202                position += buffer_position - excerpt_buffer_start;
5203            }
5204        }
5205        position
5206    }
5207
5208    pub fn latest_excerpt_id(&self, mut excerpt_id: ExcerptId) -> ExcerptId {
5209        while let Some(replacement) = self.replaced_excerpts.get(&excerpt_id) {
5210            excerpt_id = *replacement;
5211        }
5212        excerpt_id
5213    }
5214
5215    pub fn summaries_for_anchors<'a, MBD, I>(&'a self, anchors: I) -> Vec<MBD>
5216    where
5217        MBD: MultiBufferDimension
5218            + Ord
5219            + Sub<Output = MBD::TextDimension>
5220            + AddAssign<MBD::TextDimension>,
5221        MBD::TextDimension: Sub<Output = MBD::TextDimension> + Ord,
5222        I: 'a + IntoIterator<Item = &'a Anchor>,
5223    {
5224        let mut anchors = anchors.into_iter().peekable();
5225        let mut cursor = self.excerpts.cursor::<ExcerptSummary>(());
5226        let mut diff_transforms_cursor = self
5227            .diff_transforms
5228            .cursor::<Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>>(());
5229        diff_transforms_cursor.next();
5230
5231        let mut summaries = Vec::new();
5232        while let Some(anchor) = anchors.peek() {
5233            let excerpt_id = self.latest_excerpt_id(anchor.excerpt_id);
5234
5235            let excerpt_anchors = anchors.peeking_take_while(|anchor| {
5236                self.latest_excerpt_id(anchor.excerpt_id) == excerpt_id
5237            });
5238
5239            let locator = self.excerpt_locator_for_id(excerpt_id);
5240            cursor.seek_forward(locator, Bias::Left);
5241            if cursor.item().is_none() && excerpt_id == ExcerptId::max() {
5242                cursor.prev();
5243            }
5244
5245            let excerpt_start_position = ExcerptDimension(MBD::from_summary(&cursor.start().text));
5246            if let Some(excerpt) = cursor.item() {
5247                if excerpt.id != excerpt_id && excerpt_id != ExcerptId::max() {
5248                    let position = self.resolve_summary_for_min_or_max_anchor(
5249                        &Anchor::min(),
5250                        excerpt_start_position,
5251                        &mut diff_transforms_cursor,
5252                    );
5253                    summaries.extend(excerpt_anchors.map(|_| position));
5254                    continue;
5255                }
5256                let excerpt_buffer_start = excerpt
5257                    .range
5258                    .context
5259                    .start
5260                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5261                let excerpt_buffer_end = excerpt
5262                    .range
5263                    .context
5264                    .end
5265                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5266                for (buffer_summary, anchor) in excerpt
5267                    .buffer
5268                    .summaries_for_anchors_with_payload::<MBD::TextDimension, _, _>(
5269                        excerpt_anchors.map(|a| (&a.text_anchor, a)),
5270                    )
5271                {
5272                    let summary = cmp::min(excerpt_buffer_end, buffer_summary);
5273                    let mut position = excerpt_start_position;
5274                    if summary > excerpt_buffer_start {
5275                        position += summary - excerpt_buffer_start;
5276                    }
5277
5278                    if diff_transforms_cursor.start().0 < position {
5279                        diff_transforms_cursor.seek_forward(&position, Bias::Left);
5280                    }
5281
5282                    summaries.push(self.resolve_summary_for_anchor(
5283                        anchor,
5284                        position,
5285                        &mut diff_transforms_cursor,
5286                        &excerpt.buffer,
5287                    ));
5288                }
5289            } else {
5290                diff_transforms_cursor.seek_forward(&excerpt_start_position, Bias::Left);
5291                let position = self.resolve_summary_for_min_or_max_anchor(
5292                    &Anchor::max(),
5293                    excerpt_start_position,
5294                    &mut diff_transforms_cursor,
5295                );
5296                summaries.extend(excerpt_anchors.map(|_| position));
5297            }
5298        }
5299
5300        summaries
5301    }
5302
5303    pub fn dimensions_from_points<'a, MBD>(
5304        &'a self,
5305        points: impl 'a + IntoIterator<Item = Point>,
5306    ) -> impl 'a + Iterator<Item = MBD>
5307    where
5308        MBD: MultiBufferDimension + Sub + AddAssign<<MBD as Sub>::Output>,
5309    {
5310        let mut cursor = self.cursor::<DimensionPair<Point, MBD>, Point>();
5311        cursor.seek(&DimensionPair {
5312            key: Point::default(),
5313            value: None,
5314        });
5315        let mut points = points.into_iter();
5316        iter::from_fn(move || {
5317            let point = points.next()?;
5318
5319            cursor.seek_forward(&DimensionPair {
5320                key: point,
5321                value: None,
5322            });
5323
5324            if let Some(region) = cursor.region() {
5325                let overshoot = point - region.range.start.key;
5326                let buffer_point = region.buffer_range.start + overshoot;
5327                let mut position = region.range.start.value.unwrap();
5328                position.add_text_dim(
5329                    &region
5330                        .buffer
5331                        .text_summary_for_range(region.buffer_range.start..buffer_point),
5332                );
5333                if point == region.range.end.key && region.has_trailing_newline {
5334                    position.add_mb_text_summary(&MBTextSummary::from(TextSummary::newline()));
5335                }
5336                Some(position)
5337            } else {
5338                Some(MBD::from_summary(&self.text_summary()))
5339            }
5340        })
5341    }
5342
5343    pub fn refresh_anchors<'a, I>(&'a self, anchors: I) -> Vec<(usize, Anchor, bool)>
5344    where
5345        I: 'a + IntoIterator<Item = &'a Anchor>,
5346    {
5347        let mut anchors = anchors.into_iter().enumerate().peekable();
5348        let mut cursor = self.excerpts.cursor::<Option<&Locator>>(());
5349        cursor.next();
5350
5351        let mut result = Vec::new();
5352
5353        while let Some((_, anchor)) = anchors.peek() {
5354            let old_excerpt_id = anchor.excerpt_id;
5355
5356            // Find the location where this anchor's excerpt should be.
5357            let old_locator = self.excerpt_locator_for_id(old_excerpt_id);
5358            cursor.seek_forward(&Some(old_locator), Bias::Left);
5359
5360            let next_excerpt = cursor.item();
5361            let prev_excerpt = cursor.prev_item();
5362
5363            // Process all of the anchors for this excerpt.
5364            while let Some((anchor_ix, &anchor)) =
5365                anchors.next_if(|(_, anchor)| anchor.excerpt_id == old_excerpt_id)
5366            {
5367                let mut anchor = anchor;
5368
5369                // Leave min and max anchors unchanged if invalid or
5370                // if the old excerpt still exists at this location
5371                let mut kept_position = next_excerpt
5372                    .is_some_and(|e| e.id == old_excerpt_id && e.contains(&anchor))
5373                    || old_excerpt_id == ExcerptId::max()
5374                    || old_excerpt_id == ExcerptId::min();
5375
5376                // If the old excerpt no longer exists at this location, then attempt to
5377                // find an equivalent position for this anchor in an adjacent excerpt.
5378                if !kept_position {
5379                    for excerpt in [next_excerpt, prev_excerpt].iter().filter_map(|e| *e) {
5380                        if excerpt.contains(&anchor) {
5381                            anchor.excerpt_id = excerpt.id;
5382                            kept_position = true;
5383                            break;
5384                        }
5385                    }
5386                }
5387
5388                // If there's no adjacent excerpt that contains the anchor's position,
5389                // then report that the anchor has lost its position.
5390                if !kept_position {
5391                    anchor = if let Some(excerpt) = next_excerpt {
5392                        let mut text_anchor = excerpt
5393                            .range
5394                            .context
5395                            .start
5396                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
5397                        if text_anchor
5398                            .cmp(&excerpt.range.context.end, &excerpt.buffer)
5399                            .is_gt()
5400                        {
5401                            text_anchor = excerpt.range.context.end;
5402                        }
5403                        Anchor::text(excerpt.id, text_anchor)
5404                    } else if let Some(excerpt) = prev_excerpt {
5405                        let mut text_anchor = excerpt
5406                            .range
5407                            .context
5408                            .end
5409                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
5410                        if text_anchor
5411                            .cmp(&excerpt.range.context.start, &excerpt.buffer)
5412                            .is_lt()
5413                        {
5414                            text_anchor = excerpt.range.context.start;
5415                        }
5416                        Anchor::text(excerpt.id, text_anchor)
5417                    } else if anchor.text_anchor.bias == Bias::Left {
5418                        Anchor::min()
5419                    } else {
5420                        Anchor::max()
5421                    };
5422                }
5423
5424                result.push((anchor_ix, anchor, kept_position));
5425            }
5426        }
5427        result.sort_unstable_by(|a, b| a.1.cmp(&b.1, self));
5428        result
5429    }
5430
5431    pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
5432        self.anchor_at(position, Bias::Left)
5433    }
5434
5435    pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
5436        self.anchor_at(position, Bias::Right)
5437    }
5438
5439    pub fn anchor_at<T: ToOffset>(&self, position: T, mut bias: Bias) -> Anchor {
5440        let offset = position.to_offset(self);
5441
5442        // Find the given position in the diff transforms. Determine the corresponding
5443        // offset in the excerpts, and whether the position is within a deleted hunk.
5444        let mut diff_transforms = self
5445            .diff_transforms
5446            .cursor::<Dimensions<MultiBufferOffset, ExcerptOffset>>(());
5447        diff_transforms.seek(&offset, Bias::Right);
5448
5449        if offset == diff_transforms.start().0
5450            && bias == Bias::Left
5451            && let Some(prev_item) = diff_transforms.prev_item()
5452            && let DiffTransform::DeletedHunk { .. } = prev_item
5453        {
5454            diff_transforms.prev();
5455        }
5456        let offset_in_transform = offset - diff_transforms.start().0;
5457        let mut excerpt_offset = diff_transforms.start().1;
5458        let mut diff_base_anchor = None;
5459        if let Some(DiffTransform::DeletedHunk {
5460            buffer_id,
5461            base_text_byte_range,
5462            has_trailing_newline,
5463            ..
5464        }) = diff_transforms.item()
5465        {
5466            let diff = self.diffs.get(buffer_id).expect("missing diff");
5467            if offset_in_transform > base_text_byte_range.len() {
5468                debug_assert!(*has_trailing_newline);
5469                bias = Bias::Right;
5470            } else {
5471                diff_base_anchor = Some(
5472                    diff.base_text()
5473                        .anchor_at(base_text_byte_range.start + offset_in_transform, bias),
5474                );
5475                bias = Bias::Left;
5476            }
5477        } else {
5478            excerpt_offset += MultiBufferOffset(offset_in_transform);
5479        };
5480
5481        let mut excerpts = self
5482            .excerpts
5483            .cursor::<Dimensions<ExcerptOffset, Option<ExcerptId>>>(());
5484        excerpts.seek(&excerpt_offset, Bias::Right);
5485        if excerpts.item().is_none() && excerpt_offset == excerpts.start().0 && bias == Bias::Left {
5486            excerpts.prev();
5487        }
5488        if let Some(excerpt) = excerpts.item() {
5489            let mut overshoot = excerpt_offset.saturating_sub(excerpts.start().0);
5490            if excerpt.has_trailing_newline && excerpt_offset == excerpts.end().0 {
5491                overshoot -= 1;
5492                bias = Bias::Right;
5493            }
5494
5495            let buffer_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
5496            let text_anchor =
5497                excerpt.clip_anchor(excerpt.buffer.anchor_at(buffer_start + overshoot, bias));
5498            let anchor = Anchor::text(excerpt.id, text_anchor);
5499            match diff_base_anchor {
5500                Some(diff_base_anchor) => anchor.with_diff_base_anchor(diff_base_anchor),
5501                None => anchor,
5502            }
5503        } else if excerpt_offset == ExcerptDimension(MultiBufferOffset::ZERO) && bias == Bias::Left
5504        {
5505            Anchor::min()
5506        } else {
5507            Anchor::max()
5508        }
5509    }
5510
5511    /// Wraps the [`text::Anchor`] in a [`crate::Anchor`] if this multi-buffer is a singleton.
5512    pub fn as_singleton_anchor(&self, text_anchor: text::Anchor) -> Option<Anchor> {
5513        let (excerpt, buffer, _) = self.as_singleton()?;
5514        if text_anchor.buffer_id.is_none_or(|id| id == buffer) {
5515            Some(Anchor::text(excerpt, text_anchor))
5516        } else {
5517            None
5518        }
5519    }
5520
5521    /// Returns an anchor for the given excerpt and text anchor,
5522    /// Returns [`None`] if the excerpt_id is no longer valid or the text anchor range is out of excerpt's bounds.
5523    pub fn anchor_range_in_excerpt(
5524        &self,
5525        excerpt_id: ExcerptId,
5526        text_anchor: Range<text::Anchor>,
5527    ) -> Option<Range<Anchor>> {
5528        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5529
5530        Some(
5531            Self::anchor_in_excerpt_(excerpt, text_anchor.start)?
5532                ..Self::anchor_in_excerpt_(excerpt, text_anchor.end)?,
5533        )
5534    }
5535
5536    /// Returns an anchor for the given excerpt and text anchor,
5537    /// Returns [`None`] if the excerpt_id is no longer valid or the text anchor range is out of excerpt's bounds.
5538    pub fn anchor_in_excerpt(
5539        &self,
5540        excerpt_id: ExcerptId,
5541        text_anchor: text::Anchor,
5542    ) -> Option<Anchor> {
5543        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5544        Self::anchor_in_excerpt_(excerpt, text_anchor)
5545    }
5546
5547    /// Same as [`MultiBuffer::anchor_in_excerpt`], but more efficient than calling it multiple times.
5548    pub fn anchors_in_excerpt(
5549        &self,
5550        excerpt_id: ExcerptId,
5551        text_anchors: impl IntoIterator<Item = text::Anchor>,
5552    ) -> Option<impl Iterator<Item = Option<Anchor>>> {
5553        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5554        Some(
5555            text_anchors
5556                .into_iter()
5557                .map(|text_anchor| Self::anchor_in_excerpt_(excerpt, text_anchor)),
5558        )
5559    }
5560
5561    fn anchor_in_excerpt_(excerpt: &Excerpt, text_anchor: text::Anchor) -> Option<Anchor> {
5562        match text_anchor.buffer_id {
5563            Some(buffer_id) if buffer_id == excerpt.buffer_id => (),
5564            Some(_) => return None,
5565            None if text_anchor.is_max() || text_anchor.is_min() => {
5566                return Some(Anchor::text(excerpt.id, text_anchor));
5567            }
5568            None => return None,
5569        }
5570
5571        let context = &excerpt.range.context;
5572        if context.start.cmp(&text_anchor, &excerpt.buffer).is_gt()
5573            || context.end.cmp(&text_anchor, &excerpt.buffer).is_lt()
5574        {
5575            return None;
5576        }
5577
5578        Some(Anchor::text(excerpt.id, text_anchor))
5579    }
5580
5581    pub fn context_range_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<Range<text::Anchor>> {
5582        Some(self.excerpt(excerpt_id)?.range.context.clone())
5583    }
5584
5585    pub fn excerpt_range_for_excerpt(
5586        &self,
5587        excerpt_id: ExcerptId,
5588    ) -> Option<ExcerptRange<text::Anchor>> {
5589        Some(self.excerpt(excerpt_id)?.range.clone())
5590    }
5591
5592    pub fn can_resolve(&self, anchor: &Anchor) -> bool {
5593        if anchor.is_min() || anchor.is_max() {
5594            // todo(lw): should be `!self.is_empty()`
5595            true
5596        } else if let Some(excerpt) = self.excerpt(anchor.excerpt_id) {
5597            excerpt.buffer.can_resolve(&anchor.text_anchor)
5598        } else {
5599            false
5600        }
5601    }
5602
5603    pub fn excerpts(
5604        &self,
5605    ) -> impl Iterator<Item = (ExcerptId, &BufferSnapshot, ExcerptRange<text::Anchor>)> {
5606        self.excerpts
5607            .iter()
5608            .map(|excerpt| (excerpt.id, &*excerpt.buffer, excerpt.range.clone()))
5609    }
5610
5611    fn cursor<'a, MBD, BD>(&'a self) -> MultiBufferCursor<'a, MBD, BD>
5612    where
5613        MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
5614        BD: TextDimension + AddAssign<<MBD as Sub>::Output>,
5615    {
5616        let excerpts = self.excerpts.cursor(());
5617        let diff_transforms = self.diff_transforms.cursor(());
5618        MultiBufferCursor {
5619            excerpts,
5620            diff_transforms,
5621            diffs: &self.diffs,
5622            cached_region: OnceCell::new(),
5623        }
5624    }
5625
5626    pub fn excerpt_before(&self, excerpt_id: ExcerptId) -> Option<MultiBufferExcerpt<'_>> {
5627        let start_locator = self.excerpt_locator_for_id(excerpt_id);
5628        let mut excerpts = self
5629            .excerpts
5630            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
5631        excerpts.seek(&Some(start_locator), Bias::Left);
5632        excerpts.prev();
5633
5634        let mut diff_transforms = self
5635            .diff_transforms
5636            .cursor::<DiffTransforms<MultiBufferOffset>>(());
5637        diff_transforms.seek(&excerpts.start().1, Bias::Left);
5638        if diff_transforms.end().excerpt_dimension < excerpts.start().1 {
5639            diff_transforms.next();
5640        }
5641
5642        let excerpt = excerpts.item()?;
5643        Some(MultiBufferExcerpt {
5644            excerpt,
5645            offset: diff_transforms.start().output_dimension.0,
5646            buffer_offset: BufferOffset(excerpt.range.context.start.to_offset(&excerpt.buffer)),
5647            excerpt_offset: excerpts.start().1,
5648            diff_transforms,
5649        })
5650    }
5651
5652    pub fn excerpt_boundaries_in_range<R, T>(
5653        &self,
5654        range: R,
5655    ) -> impl Iterator<Item = ExcerptBoundary> + '_
5656    where
5657        R: RangeBounds<T>,
5658        T: ToOffset,
5659    {
5660        let start_offset;
5661        let start = match range.start_bound() {
5662            Bound::Included(start) => {
5663                start_offset = start.to_offset(self);
5664                Bound::Included(start_offset)
5665            }
5666            Bound::Excluded(_) => {
5667                panic!("not supported")
5668            }
5669            Bound::Unbounded => {
5670                start_offset = MultiBufferOffset::ZERO;
5671                Bound::Unbounded
5672            }
5673        };
5674        let end = match range.end_bound() {
5675            Bound::Included(end) => Bound::Included(end.to_offset(self)),
5676            Bound::Excluded(end) => Bound::Excluded(end.to_offset(self)),
5677            Bound::Unbounded => Bound::Unbounded,
5678        };
5679        let bounds = (start, end);
5680        let mut cursor = self.cursor::<DimensionPair<MultiBufferOffset, Point>, BufferOffset>();
5681        cursor.seek(&DimensionPair {
5682            key: start_offset,
5683            value: None,
5684        });
5685
5686        if cursor
5687            .fetch_excerpt_with_range()
5688            .is_some_and(|(_, range)| bounds.contains(&range.start.key))
5689        {
5690            cursor.prev_excerpt();
5691        } else {
5692            cursor.seek_to_start_of_current_excerpt();
5693        }
5694        let mut prev_region = cursor
5695            .fetch_excerpt_with_range()
5696            .map(|(excerpt, _)| excerpt);
5697
5698        cursor.next_excerpt_forwards();
5699
5700        iter::from_fn(move || {
5701            loop {
5702                if self.singleton {
5703                    return None;
5704                }
5705
5706                let (next_excerpt, next_range) = cursor.fetch_excerpt_with_range()?;
5707                cursor.next_excerpt_forwards();
5708                if !bounds.contains(&next_range.start.key) {
5709                    prev_region = Some(next_excerpt);
5710                    continue;
5711                }
5712
5713                let next_region_start = next_range.start.value.unwrap();
5714                let next_region_end = if let Some((_, range)) = cursor.fetch_excerpt_with_range() {
5715                    range.start.value.unwrap()
5716                } else {
5717                    self.max_point()
5718                };
5719
5720                let prev = prev_region.as_ref().map(|region| ExcerptBoundaryInfo {
5721                    id: region.id,
5722                    buffer: region.buffer.clone(),
5723                    buffer_id: region.buffer_id,
5724                    range: region.range.clone(),
5725                    end_row: MultiBufferRow(next_region_start.row),
5726                });
5727
5728                let next = ExcerptBoundaryInfo {
5729                    id: next_excerpt.id,
5730                    buffer: next_excerpt.buffer.clone(),
5731                    buffer_id: next_excerpt.buffer_id,
5732                    range: next_excerpt.range.clone(),
5733                    end_row: if next_excerpt.has_trailing_newline {
5734                        MultiBufferRow(next_region_end.row - 1)
5735                    } else {
5736                        MultiBufferRow(next_region_end.row)
5737                    },
5738                };
5739
5740                let row = MultiBufferRow(next_region_start.row);
5741
5742                prev_region = Some(next_excerpt);
5743
5744                return Some(ExcerptBoundary { row, prev, next });
5745            }
5746        })
5747    }
5748
5749    pub fn edit_count(&self) -> usize {
5750        self.edit_count
5751    }
5752
5753    pub fn non_text_state_update_count(&self) -> usize {
5754        self.non_text_state_update_count
5755    }
5756
5757    /// Returns the smallest enclosing bracket ranges containing the given range or
5758    /// None if no brackets contain range or the range is not contained in a single
5759    /// excerpt
5760    ///
5761    /// Can optionally pass a range_filter to filter the ranges of brackets to consider
5762    #[ztracing::instrument(skip_all)]
5763    pub fn innermost_enclosing_bracket_ranges<T: ToOffset>(
5764        &self,
5765        range: Range<T>,
5766        range_filter: Option<
5767            &dyn Fn(&BufferSnapshot, Range<BufferOffset>, Range<BufferOffset>) -> bool,
5768        >,
5769    ) -> Option<(Range<MultiBufferOffset>, Range<MultiBufferOffset>)> {
5770        let range = range.start.to_offset(self)..range.end.to_offset(self);
5771        let mut excerpt = self.excerpt_containing(range.clone())?;
5772        let buffer = excerpt.buffer();
5773        let excerpt_buffer_range = excerpt.buffer_range();
5774
5775        // Filter to ranges contained in the excerpt
5776        let range_filter = |open: Range<usize>, close: Range<usize>| -> bool {
5777            excerpt_buffer_range.contains(&BufferOffset(open.start))
5778                && excerpt_buffer_range.contains(&BufferOffset(close.end))
5779                && range_filter.is_none_or(|filter| {
5780                    filter(
5781                        buffer,
5782                        BufferOffset(open.start)..BufferOffset(close.end),
5783                        BufferOffset(close.start)..BufferOffset(close.end),
5784                    )
5785                })
5786        };
5787
5788        let (open, close) = excerpt.buffer().innermost_enclosing_bracket_ranges(
5789            excerpt.map_range_to_buffer(range),
5790            Some(&range_filter),
5791        )?;
5792
5793        Some((
5794            excerpt.map_range_from_buffer(BufferOffset(open.start)..BufferOffset(open.end)),
5795            excerpt.map_range_from_buffer(BufferOffset(close.start)..BufferOffset(close.end)),
5796        ))
5797    }
5798
5799    /// Returns enclosing bracket ranges containing the given range or returns None if the range is
5800    /// not contained in a single excerpt
5801    pub fn enclosing_bracket_ranges<T: ToOffset>(
5802        &self,
5803        range: Range<T>,
5804    ) -> Option<impl Iterator<Item = (Range<MultiBufferOffset>, Range<MultiBufferOffset>)> + '_>
5805    {
5806        let range = range.start.to_offset(self)..range.end.to_offset(self);
5807        let mut excerpt = self.excerpt_containing(range.clone())?;
5808
5809        Some(
5810            excerpt
5811                .buffer()
5812                .enclosing_bracket_ranges(excerpt.map_range_to_buffer(range))
5813                .filter_map(move |pair| {
5814                    let open_range =
5815                        BufferOffset(pair.open_range.start)..BufferOffset(pair.open_range.end);
5816                    let close_range =
5817                        BufferOffset(pair.close_range.start)..BufferOffset(pair.close_range.end);
5818                    if excerpt.contains_buffer_range(open_range.start..close_range.end) {
5819                        Some((
5820                            excerpt.map_range_from_buffer(open_range),
5821                            excerpt.map_range_from_buffer(close_range),
5822                        ))
5823                    } else {
5824                        None
5825                    }
5826                }),
5827        )
5828    }
5829
5830    /// Returns enclosing bracket ranges containing the given range or returns None if the range is
5831    /// not contained in a single excerpt
5832    pub fn text_object_ranges<T: ToOffset>(
5833        &self,
5834        range: Range<T>,
5835        options: TreeSitterOptions,
5836    ) -> impl Iterator<Item = (Range<MultiBufferOffset>, TextObject)> + '_ {
5837        let range = range.start.to_offset(self)..range.end.to_offset(self);
5838        self.excerpt_containing(range.clone())
5839            .map(|mut excerpt| {
5840                excerpt
5841                    .buffer()
5842                    .text_object_ranges(excerpt.map_range_to_buffer(range), options)
5843                    .filter_map(move |(range, text_object)| {
5844                        let range = BufferOffset(range.start)..BufferOffset(range.end);
5845                        if excerpt.contains_buffer_range(range.clone()) {
5846                            Some((excerpt.map_range_from_buffer(range), text_object))
5847                        } else {
5848                            None
5849                        }
5850                    })
5851            })
5852            .into_iter()
5853            .flatten()
5854    }
5855
5856    /// Returns bracket range pairs overlapping the given `range` or returns None if the `range` is
5857    /// not contained in a single excerpt
5858    pub fn bracket_ranges<T: ToOffset>(
5859        &self,
5860        range: Range<T>,
5861    ) -> Option<impl Iterator<Item = (Range<MultiBufferOffset>, Range<MultiBufferOffset>)> + '_>
5862    {
5863        let range = range.start.to_offset(self)..range.end.to_offset(self);
5864        let mut excerpt = self.excerpt_containing(range.clone())?;
5865        Some(
5866            excerpt
5867                .buffer()
5868                .bracket_ranges(excerpt.map_range_to_buffer(range))
5869                .filter_map(move |pair| {
5870                    let open_range =
5871                        BufferOffset(pair.open_range.start)..BufferOffset(pair.open_range.end);
5872                    let close_range =
5873                        BufferOffset(pair.close_range.start)..BufferOffset(pair.close_range.end);
5874                    excerpt
5875                        .contains_buffer_range(open_range.start..close_range.end)
5876                        .then(|| BracketMatch {
5877                            open_range: excerpt.map_range_from_buffer(open_range),
5878                            close_range: excerpt.map_range_from_buffer(close_range),
5879                            color_index: pair.color_index,
5880                            newline_only: pair.newline_only,
5881                            syntax_layer_depth: pair.syntax_layer_depth,
5882                        })
5883                })
5884                .map(BracketMatch::bracket_ranges),
5885        )
5886    }
5887
5888    pub fn redacted_ranges<'a, T: ToOffset>(
5889        &'a self,
5890        range: Range<T>,
5891        redaction_enabled: impl Fn(Option<&Arc<dyn File>>) -> bool + 'a,
5892    ) -> impl Iterator<Item = Range<MultiBufferOffset>> + 'a {
5893        let range = range.start.to_offset(self)..range.end.to_offset(self);
5894        self.lift_buffer_metadata(range, move |buffer, range| {
5895            if redaction_enabled(buffer.file()) {
5896                Some(buffer.redacted_ranges(range).map(|range| (range, ())))
5897            } else {
5898                None
5899            }
5900        })
5901        .map(|(range, _, _)| range)
5902    }
5903
5904    pub fn runnable_ranges(
5905        &self,
5906        range: Range<Anchor>,
5907    ) -> impl Iterator<Item = (Range<MultiBufferOffset>, language::RunnableRange)> + '_ {
5908        let range = range.start.to_offset(self)..range.end.to_offset(self);
5909        self.lift_buffer_metadata(range, move |buffer, range| {
5910            Some(
5911                buffer
5912                    .runnable_ranges(range.clone())
5913                    .filter(move |runnable| {
5914                        runnable.run_range.start >= range.start
5915                            && runnable.run_range.end < range.end
5916                    })
5917                    .map(|runnable| (runnable.run_range.clone(), runnable)),
5918            )
5919        })
5920        .map(|(run_range, runnable, _)| (run_range, runnable))
5921    }
5922
5923    pub fn line_indents(
5924        &self,
5925        start_row: MultiBufferRow,
5926        buffer_filter: impl Fn(&BufferSnapshot) -> bool,
5927    ) -> impl Iterator<Item = (MultiBufferRow, LineIndent, &BufferSnapshot)> {
5928        let max_point = self.max_point();
5929        let mut cursor = self.cursor::<Point, Point>();
5930        cursor.seek(&Point::new(start_row.0, 0));
5931        iter::from_fn(move || {
5932            let mut region = cursor.region()?;
5933            while !buffer_filter(&region.excerpt.buffer) {
5934                cursor.next();
5935                region = cursor.region()?;
5936            }
5937            let region = cursor.region()?;
5938            let overshoot = start_row.0.saturating_sub(region.range.start.row);
5939            let buffer_start_row =
5940                (region.buffer_range.start.row + overshoot).min(region.buffer_range.end.row);
5941
5942            let buffer_end_row = if region.is_main_buffer
5943                && (region.has_trailing_newline || region.range.end == max_point)
5944            {
5945                region.buffer_range.end.row
5946            } else {
5947                region.buffer_range.end.row.saturating_sub(1)
5948            };
5949
5950            let line_indents = region
5951                .buffer
5952                .line_indents_in_row_range(buffer_start_row..buffer_end_row);
5953            let region_buffer_row = region.buffer_range.start.row;
5954            let region_row = region.range.start.row;
5955            let region_buffer = &region.excerpt.buffer;
5956            cursor.next();
5957            Some(line_indents.map(move |(buffer_row, indent)| {
5958                let row = region_row + (buffer_row - region_buffer_row);
5959                (MultiBufferRow(row), indent, region_buffer.as_ref())
5960            }))
5961        })
5962        .flatten()
5963    }
5964
5965    pub fn reversed_line_indents(
5966        &self,
5967        end_row: MultiBufferRow,
5968        buffer_filter: impl Fn(&BufferSnapshot) -> bool,
5969    ) -> impl Iterator<Item = (MultiBufferRow, LineIndent, &BufferSnapshot)> {
5970        let max_point = self.max_point();
5971        let mut cursor = self.cursor::<Point, Point>();
5972        cursor.seek(&Point::new(end_row.0, 0));
5973        iter::from_fn(move || {
5974            let mut region = cursor.region()?;
5975            while !buffer_filter(&region.excerpt.buffer) {
5976                cursor.prev();
5977                region = cursor.region()?;
5978            }
5979            let region = cursor.region()?;
5980
5981            let buffer_start_row = region.buffer_range.start.row;
5982            let buffer_end_row = if region.is_main_buffer
5983                && (region.has_trailing_newline || region.range.end == max_point)
5984            {
5985                region.buffer_range.end.row + 1
5986            } else {
5987                region.buffer_range.end.row
5988            };
5989
5990            let overshoot = end_row.0 - region.range.start.row;
5991            let buffer_end_row =
5992                (region.buffer_range.start.row + overshoot + 1).min(buffer_end_row);
5993
5994            let line_indents = region
5995                .buffer
5996                .reversed_line_indents_in_row_range(buffer_start_row..buffer_end_row);
5997            let region_buffer_row = region.buffer_range.start.row;
5998            let region_row = region.range.start.row;
5999            let region_buffer = &region.excerpt.buffer;
6000            cursor.prev();
6001            Some(line_indents.map(move |(buffer_row, indent)| {
6002                let row = region_row + (buffer_row - region_buffer_row);
6003                (MultiBufferRow(row), indent, region_buffer.as_ref())
6004            }))
6005        })
6006        .flatten()
6007    }
6008
6009    pub async fn enclosing_indent(
6010        &self,
6011        mut target_row: MultiBufferRow,
6012    ) -> Option<(Range<MultiBufferRow>, LineIndent)> {
6013        let max_row = MultiBufferRow(self.max_point().row);
6014        if target_row >= max_row {
6015            return None;
6016        }
6017
6018        let mut target_indent = self.line_indent_for_row(target_row);
6019
6020        // If the current row is at the start of an indented block, we want to return this
6021        // block as the enclosing indent.
6022        if !target_indent.is_line_empty() && target_row < max_row {
6023            let next_line_indent = self.line_indent_for_row(MultiBufferRow(target_row.0 + 1));
6024            if !next_line_indent.is_line_empty()
6025                && target_indent.raw_len() < next_line_indent.raw_len()
6026            {
6027                target_indent = next_line_indent;
6028                target_row.0 += 1;
6029            }
6030        }
6031
6032        const SEARCH_ROW_LIMIT: u32 = 25000;
6033        const SEARCH_WHITESPACE_ROW_LIMIT: u32 = 2500;
6034        const YIELD_INTERVAL: u32 = 100;
6035
6036        let mut accessed_row_counter = 0;
6037
6038        // If there is a blank line at the current row, search for the next non indented lines
6039        if target_indent.is_line_empty() {
6040            let start = MultiBufferRow(target_row.0.saturating_sub(SEARCH_WHITESPACE_ROW_LIMIT));
6041            let end =
6042                MultiBufferRow((max_row.0 + 1).min(target_row.0 + SEARCH_WHITESPACE_ROW_LIMIT));
6043
6044            let mut non_empty_line_above = None;
6045            for (row, indent, _) in self.reversed_line_indents(target_row, |_| true) {
6046                if row < start {
6047                    break;
6048                }
6049                accessed_row_counter += 1;
6050                if accessed_row_counter == YIELD_INTERVAL {
6051                    accessed_row_counter = 0;
6052                    yield_now().await;
6053                }
6054                if !indent.is_line_empty() {
6055                    non_empty_line_above = Some((row, indent));
6056                    break;
6057                }
6058            }
6059
6060            let mut non_empty_line_below = None;
6061            for (row, indent, _) in self.line_indents(target_row, |_| true) {
6062                if row > end {
6063                    break;
6064                }
6065                accessed_row_counter += 1;
6066                if accessed_row_counter == YIELD_INTERVAL {
6067                    accessed_row_counter = 0;
6068                    yield_now().await;
6069                }
6070                if !indent.is_line_empty() {
6071                    non_empty_line_below = Some((row, indent));
6072                    break;
6073                }
6074            }
6075
6076            let (row, indent) = match (non_empty_line_above, non_empty_line_below) {
6077                (Some((above_row, above_indent)), Some((below_row, below_indent))) => {
6078                    if above_indent.raw_len() >= below_indent.raw_len() {
6079                        (above_row, above_indent)
6080                    } else {
6081                        (below_row, below_indent)
6082                    }
6083                }
6084                (Some(above), None) => above,
6085                (None, Some(below)) => below,
6086                _ => return None,
6087            };
6088
6089            target_indent = indent;
6090            target_row = row;
6091        }
6092
6093        let start = MultiBufferRow(target_row.0.saturating_sub(SEARCH_ROW_LIMIT));
6094        let end = MultiBufferRow((max_row.0 + 1).min(target_row.0 + SEARCH_ROW_LIMIT));
6095
6096        let mut start_indent = None;
6097        for (row, indent, _) in self.reversed_line_indents(target_row, |_| true) {
6098            if row < start {
6099                break;
6100            }
6101            accessed_row_counter += 1;
6102            if accessed_row_counter == YIELD_INTERVAL {
6103                accessed_row_counter = 0;
6104                yield_now().await;
6105            }
6106            if !indent.is_line_empty() && indent.raw_len() < target_indent.raw_len() {
6107                start_indent = Some((row, indent));
6108                break;
6109            }
6110        }
6111        let (start_row, start_indent_size) = start_indent?;
6112
6113        let mut end_indent = (end, None);
6114        for (row, indent, _) in self.line_indents(target_row, |_| true) {
6115            if row > end {
6116                break;
6117            }
6118            accessed_row_counter += 1;
6119            if accessed_row_counter == YIELD_INTERVAL {
6120                accessed_row_counter = 0;
6121                yield_now().await;
6122            }
6123            if !indent.is_line_empty() && indent.raw_len() < target_indent.raw_len() {
6124                end_indent = (MultiBufferRow(row.0.saturating_sub(1)), Some(indent));
6125                break;
6126            }
6127        }
6128        let (end_row, end_indent_size) = end_indent;
6129
6130        let indent = if let Some(end_indent_size) = end_indent_size {
6131            if start_indent_size.raw_len() > end_indent_size.raw_len() {
6132                start_indent_size
6133            } else {
6134                end_indent_size
6135            }
6136        } else {
6137            start_indent_size
6138        };
6139
6140        Some((start_row..end_row, indent))
6141    }
6142
6143    pub fn indent_guides_in_range<T: ToPoint>(
6144        &self,
6145        range: Range<T>,
6146        ignore_disabled_for_language: bool,
6147        cx: &App,
6148    ) -> impl Iterator<Item = IndentGuide> {
6149        let range = range.start.to_point(self)..range.end.to_point(self);
6150        let start_row = MultiBufferRow(range.start.row);
6151        let end_row = MultiBufferRow(range.end.row);
6152
6153        let mut row_indents = self.line_indents(start_row, |buffer| {
6154            let settings =
6155                language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx);
6156            settings.indent_guides.enabled || ignore_disabled_for_language
6157        });
6158
6159        let mut result = Vec::new();
6160        let mut indent_stack = SmallVec::<[IndentGuide; 8]>::new();
6161
6162        let mut prev_settings = None;
6163        while let Some((first_row, mut line_indent, buffer)) = row_indents.next() {
6164            if first_row > end_row {
6165                break;
6166            }
6167            let current_depth = indent_stack.len() as u32;
6168
6169            // Avoid retrieving the language settings repeatedly for every buffer row.
6170            if let Some((prev_buffer_id, _)) = &prev_settings
6171                && prev_buffer_id != &buffer.remote_id()
6172            {
6173                prev_settings.take();
6174            }
6175            let settings = &prev_settings
6176                .get_or_insert_with(|| {
6177                    (
6178                        buffer.remote_id(),
6179                        language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx),
6180                    )
6181                })
6182                .1;
6183            let tab_size = settings.tab_size.get();
6184
6185            // When encountering empty, continue until found useful line indent
6186            // then add to the indent stack with the depth found
6187            let mut found_indent = false;
6188            let mut last_row = first_row;
6189            if line_indent.is_line_blank() {
6190                while !found_indent {
6191                    let Some((target_row, new_line_indent, _)) = row_indents.next() else {
6192                        break;
6193                    };
6194                    const TRAILING_ROW_SEARCH_LIMIT: u32 = 25;
6195                    if target_row > MultiBufferRow(end_row.0 + TRAILING_ROW_SEARCH_LIMIT) {
6196                        break;
6197                    }
6198
6199                    if new_line_indent.is_line_blank() {
6200                        continue;
6201                    }
6202                    last_row = target_row.min(end_row);
6203                    line_indent = new_line_indent;
6204                    found_indent = true;
6205                    break;
6206                }
6207            } else {
6208                found_indent = true
6209            }
6210
6211            let depth = if found_indent {
6212                line_indent.len(tab_size) / tab_size
6213            } else {
6214                0
6215            };
6216
6217            match depth.cmp(&current_depth) {
6218                cmp::Ordering::Less => {
6219                    for _ in 0..(current_depth - depth) {
6220                        let mut indent = indent_stack.pop().unwrap();
6221                        if last_row != first_row {
6222                            // In this case, we landed on an empty row, had to seek forward,
6223                            // and discovered that the indent we where on is ending.
6224                            // This means that the last display row must
6225                            // be on line that ends this indent range, so we
6226                            // should display the range up to the first non-empty line
6227                            indent.end_row = MultiBufferRow(first_row.0.saturating_sub(1));
6228                        }
6229
6230                        result.push(indent)
6231                    }
6232                }
6233                cmp::Ordering::Greater => {
6234                    for next_depth in current_depth..depth {
6235                        indent_stack.push(IndentGuide {
6236                            buffer_id: buffer.remote_id(),
6237                            start_row: first_row,
6238                            end_row: last_row,
6239                            depth: next_depth,
6240                            tab_size,
6241                            settings: settings.indent_guides.clone(),
6242                        });
6243                    }
6244                }
6245                _ => {}
6246            }
6247
6248            for indent in indent_stack.iter_mut() {
6249                indent.end_row = last_row;
6250            }
6251        }
6252
6253        result.extend(indent_stack);
6254        result.into_iter()
6255    }
6256
6257    pub fn trailing_excerpt_update_count(&self) -> usize {
6258        self.trailing_excerpt_update_count
6259    }
6260
6261    pub fn file_at<T: ToOffset>(&self, point: T) -> Option<&Arc<dyn File>> {
6262        self.point_to_buffer_offset(point)
6263            .and_then(|(buffer, _)| buffer.file())
6264    }
6265
6266    pub fn language_at<T: ToOffset>(&self, offset: T) -> Option<&Arc<Language>> {
6267        self.point_to_buffer_offset(offset)
6268            .and_then(|(buffer, offset)| buffer.language_at(offset))
6269    }
6270
6271    fn language_settings<'a>(&'a self, cx: &'a App) -> Cow<'a, LanguageSettings> {
6272        self.excerpts
6273            .first()
6274            .map(|excerpt| &excerpt.buffer)
6275            .map(|buffer| {
6276                language_settings(
6277                    buffer.language().map(|language| language.name()),
6278                    buffer.file(),
6279                    cx,
6280                )
6281            })
6282            .unwrap_or_else(move || self.language_settings_at(MultiBufferOffset::ZERO, cx))
6283    }
6284
6285    pub fn language_settings_at<'a, T: ToOffset>(
6286        &'a self,
6287        point: T,
6288        cx: &'a App,
6289    ) -> Cow<'a, LanguageSettings> {
6290        let mut language = None;
6291        let mut file = None;
6292        if let Some((buffer, offset)) = self.point_to_buffer_offset(point) {
6293            language = buffer.language_at(offset);
6294            file = buffer.file();
6295        }
6296        language_settings(language.map(|l| l.name()), file, cx)
6297    }
6298
6299    pub fn language_scope_at<T: ToOffset>(&self, point: T) -> Option<LanguageScope> {
6300        self.point_to_buffer_offset(point)
6301            .and_then(|(buffer, offset)| buffer.language_scope_at(offset))
6302    }
6303
6304    pub fn char_classifier_at<T: ToOffset>(&self, point: T) -> CharClassifier {
6305        self.point_to_buffer_offset(point)
6306            .map(|(buffer, offset)| buffer.char_classifier_at(offset))
6307            .unwrap_or_default()
6308    }
6309
6310    pub fn language_indent_size_at<T: ToOffset>(
6311        &self,
6312        position: T,
6313        cx: &App,
6314    ) -> Option<IndentSize> {
6315        let (buffer_snapshot, offset) = self.point_to_buffer_offset(position)?;
6316        Some(buffer_snapshot.language_indent_size_at(offset, cx))
6317    }
6318
6319    pub fn is_dirty(&self) -> bool {
6320        self.is_dirty
6321    }
6322
6323    pub fn has_deleted_file(&self) -> bool {
6324        self.has_deleted_file
6325    }
6326
6327    pub fn has_conflict(&self) -> bool {
6328        self.has_conflict
6329    }
6330
6331    pub fn has_diagnostics(&self) -> bool {
6332        self.excerpts
6333            .iter()
6334            .any(|excerpt| excerpt.buffer.has_diagnostics())
6335    }
6336
6337    pub fn diagnostic_group(
6338        &self,
6339        buffer_id: BufferId,
6340        group_id: usize,
6341    ) -> impl Iterator<Item = DiagnosticEntryRef<'_, Point>> + '_ {
6342        self.lift_buffer_metadata::<Point, _, _>(
6343            Point::zero()..self.max_point(),
6344            move |buffer, range| {
6345                if buffer.remote_id() != buffer_id {
6346                    return None;
6347                };
6348                Some(
6349                    buffer
6350                        .diagnostics_in_range(range, false)
6351                        .filter(move |diagnostic| diagnostic.diagnostic.group_id == group_id)
6352                        .map(move |DiagnosticEntryRef { diagnostic, range }| (range, diagnostic)),
6353                )
6354            },
6355        )
6356        .map(|(range, diagnostic, _)| DiagnosticEntryRef { diagnostic, range })
6357    }
6358
6359    pub fn diagnostics_in_range<'a, MBD>(
6360        &'a self,
6361        range: Range<MBD>,
6362    ) -> impl Iterator<Item = DiagnosticEntryRef<'a, MBD>> + 'a
6363    where
6364        MBD::TextDimension: 'a
6365            + text::ToOffset
6366            + text::FromAnchor
6367            + Sub<Output = MBD::TextDimension>
6368            + fmt::Debug
6369            + ops::Add<Output = MBD::TextDimension>
6370            + ops::AddAssign
6371            + Ord,
6372        MBD: MultiBufferDimension
6373            + Ord
6374            + Sub<Output = MBD::TextDimension>
6375            + ops::Add<MBD::TextDimension, Output = MBD>
6376            + ops::AddAssign<MBD::TextDimension>
6377            + 'a,
6378    {
6379        self.lift_buffer_metadata::<MBD, _, _>(range, move |buffer, buffer_range| {
6380            Some(
6381                buffer
6382                    .diagnostics_in_range(buffer_range.start..buffer_range.end, false)
6383                    .map(|entry| (entry.range, entry.diagnostic)),
6384            )
6385        })
6386        .map(|(range, diagnostic, _)| DiagnosticEntryRef { diagnostic, range })
6387    }
6388
6389    pub fn diagnostics_with_buffer_ids_in_range<'a, MBD>(
6390        &'a self,
6391        range: Range<MBD>,
6392    ) -> impl Iterator<Item = (BufferId, DiagnosticEntryRef<'a, MBD>)> + 'a
6393    where
6394        MBD: MultiBufferDimension
6395            + Ord
6396            + Sub<Output = MBD::TextDimension>
6397            + ops::Add<MBD::TextDimension, Output = MBD>
6398            + ops::AddAssign<MBD::TextDimension>,
6399        MBD::TextDimension: Sub<Output = MBD::TextDimension>
6400            + ops::Add<Output = MBD::TextDimension>
6401            + text::ToOffset
6402            + text::FromAnchor
6403            + AddAssign<MBD::TextDimension>
6404            + Ord,
6405    {
6406        self.lift_buffer_metadata::<MBD, _, _>(range, move |buffer, buffer_range| {
6407            Some(
6408                buffer
6409                    .diagnostics_in_range(buffer_range.start..buffer_range.end, false)
6410                    .map(|entry| (entry.range, entry.diagnostic)),
6411            )
6412        })
6413        .map(|(range, diagnostic, b)| (b.buffer_id, DiagnosticEntryRef { diagnostic, range }))
6414    }
6415
6416    pub fn syntax_ancestor<T: ToOffset>(
6417        &self,
6418        range: Range<T>,
6419    ) -> Option<(tree_sitter::Node<'_>, Range<MultiBufferOffset>)> {
6420        let range = range.start.to_offset(self)..range.end.to_offset(self);
6421        let mut excerpt = self.excerpt_containing(range.clone())?;
6422        let node = excerpt
6423            .buffer()
6424            .syntax_ancestor(excerpt.map_range_to_buffer(range))?;
6425        let node_range = node.byte_range();
6426        let node_range = BufferOffset(node_range.start)..BufferOffset(node_range.end);
6427        if !excerpt.contains_buffer_range(node_range.clone()) {
6428            return None;
6429        };
6430        Some((node, excerpt.map_range_from_buffer(node_range)))
6431    }
6432
6433    pub fn outline(&self, theme: Option<&SyntaxTheme>) -> Option<Outline<Anchor>> {
6434        let (excerpt_id, _, buffer) = self.as_singleton()?;
6435        let outline = buffer.outline(theme);
6436        Some(Outline::new(
6437            outline
6438                .items
6439                .into_iter()
6440                .flat_map(|item| {
6441                    Some(OutlineItem {
6442                        depth: item.depth,
6443                        range: self.anchor_range_in_excerpt(excerpt_id, item.range)?,
6444                        source_range_for_text: self
6445                            .anchor_range_in_excerpt(excerpt_id, item.source_range_for_text)?,
6446                        text: item.text,
6447                        highlight_ranges: item.highlight_ranges,
6448                        name_ranges: item.name_ranges,
6449                        body_range: item.body_range.and_then(|body_range| {
6450                            self.anchor_range_in_excerpt(excerpt_id, body_range)
6451                        }),
6452                        annotation_range: item.annotation_range.and_then(|annotation_range| {
6453                            self.anchor_range_in_excerpt(excerpt_id, annotation_range)
6454                        }),
6455                    })
6456                })
6457                .collect(),
6458        ))
6459    }
6460
6461    pub fn symbols_containing<T: ToOffset>(
6462        &self,
6463        offset: T,
6464        theme: Option<&SyntaxTheme>,
6465    ) -> Option<(BufferId, Vec<OutlineItem<Anchor>>)> {
6466        let anchor = self.anchor_before(offset);
6467        let excerpt @ &Excerpt {
6468            id: excerpt_id,
6469            buffer_id,
6470            ref buffer,
6471            ..
6472        } = self.excerpt(anchor.excerpt_id)?;
6473        if cfg!(debug_assertions) {
6474            match anchor.text_anchor.buffer_id {
6475                // we clearly are hitting this according to sentry, but in what situations can this occur?
6476                Some(anchor_buffer_id) => {
6477                    assert_eq!(
6478                        anchor_buffer_id, buffer_id,
6479                        "anchor {anchor:?} does not match with resolved excerpt {excerpt:?}"
6480                    )
6481                }
6482                None => assert!(anchor.is_max()),
6483            }
6484        };
6485        Some((
6486            buffer_id,
6487            buffer
6488                .symbols_containing(anchor.text_anchor, theme)
6489                .into_iter()
6490                .flat_map(|item| {
6491                    Some(OutlineItem {
6492                        depth: item.depth,
6493                        source_range_for_text: Anchor::range_in_buffer(
6494                            excerpt_id,
6495                            item.source_range_for_text,
6496                        ),
6497                        range: Anchor::range_in_buffer(excerpt_id, item.range),
6498                        text: item.text,
6499                        highlight_ranges: item.highlight_ranges,
6500                        name_ranges: item.name_ranges,
6501                        body_range: item
6502                            .body_range
6503                            .map(|body_range| Anchor::range_in_buffer(excerpt_id, body_range)),
6504                        annotation_range: item
6505                            .annotation_range
6506                            .map(|body_range| Anchor::range_in_buffer(excerpt_id, body_range)),
6507                    })
6508                })
6509                .collect(),
6510        ))
6511    }
6512
6513    fn anchor_seek_target(&self, anchor: Anchor) -> Option<AnchorSeekTarget> {
6514        match anchor {
6515            Anchor::Min => Some(AnchorSeekTarget::Min),
6516            Anchor::Max => Some(AnchorSeekTarget::Max),
6517            Anchor::Text { buffer_id, .. } => {
6518                let Some(path_key) = self.path_for_buffer(buffer_id) else {
6519                    return None;
6520                };
6521                let Some(snapshot) = self.buffer_for_path(path_key) else {
6522                    return None;
6523                };
6524
6525                Some(AnchorSeekTarget::Text {
6526                    path_key: path_key.clone(),
6527                    anchor: anchor.text_anchor().unwrap(),
6528                    snapshot: snapshot.clone(),
6529                })
6530            }
6531        }
6532    }
6533
6534    fn excerpt_locator_for_id(&self, id: ExcerptId) -> &Locator {
6535        self.try_excerpt_locator_for_id(id)
6536            .unwrap_or_else(|| panic!("invalid excerpt id {id:?}"))
6537    }
6538
6539    fn try_excerpt_locator_for_id(&self, id: ExcerptId) -> Option<&Locator> {
6540        if id == ExcerptId::min() {
6541            Some(Locator::min_ref())
6542        } else if id == ExcerptId::max() {
6543            Some(Locator::max_ref())
6544        } else {
6545            let (_, _, item) = self.excerpt_ids.find::<ExcerptId, _>((), &id, Bias::Left);
6546            if let Some(entry) = item
6547                && entry.id == id
6548            {
6549                return Some(&entry.locator);
6550            }
6551            None
6552        }
6553    }
6554
6555    /// Returns the locators referenced by the given excerpt IDs, sorted by locator.
6556    fn excerpt_locators_for_ids(
6557        &self,
6558        ids: impl IntoIterator<Item = ExcerptId>,
6559    ) -> SmallVec<[Locator; 1]> {
6560        let mut sorted_ids = ids.into_iter().collect::<SmallVec<[_; 1]>>();
6561        sorted_ids.sort_unstable();
6562        sorted_ids.dedup();
6563        let mut locators = SmallVec::new();
6564
6565        while sorted_ids.last() == Some(&ExcerptId::max()) {
6566            sorted_ids.pop();
6567            locators.push(Locator::max());
6568        }
6569
6570        let mut sorted_ids = sorted_ids.into_iter().peekable();
6571        locators.extend(
6572            sorted_ids
6573                .peeking_take_while(|excerpt| *excerpt == ExcerptId::min())
6574                .map(|_| Locator::min()),
6575        );
6576
6577        let mut cursor = self.excerpt_ids.cursor::<ExcerptId>(());
6578        for id in sorted_ids {
6579            if cursor.seek_forward(&id, Bias::Left) {
6580                locators.push(cursor.item().unwrap().locator.clone());
6581            } else {
6582                panic!("invalid excerpt id {:?}", id);
6583            }
6584        }
6585
6586        locators.sort_unstable();
6587        locators
6588    }
6589
6590    pub fn buffer_id_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<BufferId> {
6591        Some(self.excerpt(excerpt_id)?.buffer_id)
6592    }
6593
6594    pub fn buffer_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<&BufferSnapshot> {
6595        Some(&self.excerpt(excerpt_id)?.buffer)
6596    }
6597
6598    pub fn buffer_for_path(&self, path: &PathKey) -> Option<&BufferSnapshot> {
6599        todo!()
6600    }
6601
6602    pub fn path_for_buffer(&self, buffer_id: BufferId) -> Option<&PathKey> {
6603        self.path_keys.get(&buffer_id)
6604    }
6605
6606    pub fn buffer_for_id(&self, id: BufferId) -> Option<&BufferSnapshot> {
6607        self.buffer_for_path(self.path_keys.get(&id)?)
6608    }
6609
6610    pub fn range_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<Range<Point>> {
6611        let mut cursor = self
6612            .excerpts
6613            .cursor::<Dimensions<Option<&Locator>, ExcerptPoint>>(());
6614        let locator = self.excerpt_locator_for_id(excerpt_id);
6615        let mut sought_exact = cursor.seek(&Some(locator), Bias::Left);
6616        if cursor.item().is_none() && excerpt_id == ExcerptId::max() {
6617            sought_exact = true;
6618            cursor.prev();
6619        } else if excerpt_id == ExcerptId::min() {
6620            sought_exact = true;
6621        }
6622        if sought_exact {
6623            let start = cursor.start().1;
6624            let end = cursor.end().1;
6625            let mut diff_transforms = self
6626                .diff_transforms
6627                .cursor::<Dimensions<ExcerptPoint, OutputDimension<Point>>>(());
6628            diff_transforms.seek(&start, Bias::Left);
6629            let overshoot = start - diff_transforms.start().0;
6630            let start = diff_transforms.start().1 + overshoot;
6631            diff_transforms.seek(&end, Bias::Right);
6632            let overshoot = end - diff_transforms.start().0;
6633            let end = diff_transforms.start().1 + overshoot;
6634            Some(start.0..end.0)
6635        } else {
6636            None
6637        }
6638    }
6639
6640    /// Returns the excerpt for the given id. The returned excerpt is guaranteed
6641    /// to have the latest excerpt id for the one passed in and will also remap
6642    /// `ExcerptId::max()` to the corresponding excertp ID.
6643    ///
6644    /// Callers of this function should generally use the resulting excerpt's `id` field
6645    /// afterwards.
6646    fn excerpt(&self, excerpt_id: ExcerptId) -> Option<&Excerpt> {
6647        let excerpt_id = self.latest_excerpt_id(excerpt_id);
6648        let locator = self.try_excerpt_locator_for_id(excerpt_id)?;
6649        let (_, _, item) =
6650            self.excerpts
6651                .find::<Option<&Locator>, _>((), &Some(locator), Bias::Left);
6652        if let Some(excerpt) = item
6653            && excerpt.id == excerpt_id
6654        {
6655            return Some(excerpt);
6656        } else if item.is_none() && excerpt_id == ExcerptId::max() {
6657            return self.excerpts.last();
6658        }
6659        None
6660    }
6661
6662    /// Returns the excerpt containing range and its offset start within the multibuffer or none if `range` spans multiple excerpts
6663    pub fn excerpt_containing<T: ToOffset>(
6664        &self,
6665        range: Range<T>,
6666    ) -> Option<MultiBufferExcerpt<'_>> {
6667        let range = range.start.to_offset(self)..range.end.to_offset(self);
6668        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
6669        cursor.seek(&range.start);
6670
6671        let start_excerpt = cursor.excerpt()?;
6672        if range.end != range.start {
6673            cursor.seek_forward(&range.end);
6674            if cursor.excerpt()?.id != start_excerpt.id {
6675                return None;
6676            }
6677        }
6678
6679        cursor.seek_to_start_of_current_excerpt();
6680        let region = cursor.region()?;
6681        let offset = region.range.start;
6682        let buffer_offset = start_excerpt.buffer_start_offset();
6683        let excerpt_offset = *cursor.excerpts.start();
6684        Some(MultiBufferExcerpt {
6685            diff_transforms: cursor.diff_transforms,
6686            excerpt: start_excerpt,
6687            offset,
6688            buffer_offset,
6689            excerpt_offset,
6690        })
6691    }
6692
6693    pub fn buffer_id_for_anchor(&self, anchor: Anchor) -> Option<BufferId> {
6694        if let Some(id) = anchor.text_anchor.buffer_id {
6695            return Some(id);
6696        }
6697        let excerpt = self.excerpt_containing(anchor..anchor)?;
6698        Some(excerpt.buffer_id())
6699    }
6700
6701    pub fn selections_in_range<'a>(
6702        &'a self,
6703        range: &'a Range<Anchor>,
6704        include_local: bool,
6705    ) -> impl 'a + Iterator<Item = (ReplicaId, bool, CursorShape, Selection<Anchor>)> {
6706        let mut cursor = self.excerpts.cursor::<ExcerptSummary>(());
6707        let start_locator = self.excerpt_locator_for_id(range.start.excerpt_id);
6708        let end_locator = self.excerpt_locator_for_id(range.end.excerpt_id);
6709        cursor.seek(start_locator, Bias::Left);
6710        cursor
6711            .take_while(move |excerpt| excerpt.locator <= *end_locator)
6712            .flat_map(move |excerpt| {
6713                let mut query_range = excerpt.range.context.start..excerpt.range.context.end;
6714                if excerpt.id == range.start.excerpt_id {
6715                    query_range.start = range.start.text_anchor;
6716                }
6717                if excerpt.id == range.end.excerpt_id {
6718                    query_range.end = range.end.text_anchor;
6719                }
6720
6721                excerpt
6722                    .buffer
6723                    .selections_in_range(query_range, include_local)
6724                    .flat_map(move |(replica_id, line_mode, cursor_shape, selections)| {
6725                        selections.map(move |selection| {
6726                            let mut start = Anchor::text(excerpt.id, selection.start);
6727                            let mut end = Anchor::text(excerpt.id, selection.end);
6728                            if range.start.cmp(&start, self).is_gt() {
6729                                start = range.start;
6730                            }
6731                            if range.end.cmp(&end, self).is_lt() {
6732                                end = range.end;
6733                            }
6734
6735                            (
6736                                replica_id,
6737                                line_mode,
6738                                cursor_shape,
6739                                Selection {
6740                                    id: selection.id,
6741                                    start,
6742                                    end,
6743                                    reversed: selection.reversed,
6744                                    goal: selection.goal,
6745                                },
6746                            )
6747                        })
6748                    })
6749            })
6750    }
6751
6752    pub fn show_headers(&self) -> bool {
6753        self.show_headers
6754    }
6755
6756    pub fn diff_for_buffer_id(&self, buffer_id: BufferId) -> Option<&BufferDiffSnapshot> {
6757        self.diffs.get(&buffer_id).map(|diff| &diff.diff)
6758    }
6759
6760    pub fn all_diff_hunks_expanded(&self) -> bool {
6761        self.all_diff_hunks_expanded
6762    }
6763
6764    /// Visually annotates a position or range with the `Debug` representation of a value. The
6765    /// callsite of this function is used as a key - previous annotations will be removed.
6766    #[cfg(debug_assertions)]
6767    #[track_caller]
6768    pub fn debug<V, R>(&self, ranges: &R, value: V)
6769    where
6770        R: debug::ToMultiBufferDebugRanges,
6771        V: std::fmt::Debug,
6772    {
6773        self.debug_with_key(std::panic::Location::caller(), ranges, value);
6774    }
6775
6776    /// Visually annotates a position or range with the `Debug` representation of a value. Previous
6777    /// debug annotations with the same key will be removed. The key is also used to determine the
6778    /// annotation's color.
6779    #[cfg(debug_assertions)]
6780    #[track_caller]
6781    pub fn debug_with_key<K, R, V>(&self, key: &K, ranges: &R, value: V)
6782    where
6783        K: std::hash::Hash + 'static,
6784        R: debug::ToMultiBufferDebugRanges,
6785        V: std::fmt::Debug,
6786    {
6787        let text_ranges = ranges
6788            .to_multi_buffer_debug_ranges(self)
6789            .into_iter()
6790            .flat_map(|range| {
6791                self.range_to_buffer_ranges(range.start..=range.end)
6792                    .into_iter()
6793                    .map(|(buffer, range, _excerpt_id)| {
6794                        buffer.anchor_after(range.start)..buffer.anchor_before(range.end)
6795                    })
6796            })
6797            .collect();
6798        text::debug::GlobalDebugRanges::with_locked(|debug_ranges| {
6799            debug_ranges.insert(key, text_ranges, format!("{value:?}").into())
6800        });
6801    }
6802
6803    fn excerpt_edits_for_diff_change(
6804        &self,
6805        buffer_state: &BufferState,
6806        diff_change_range: Range<usize>,
6807    ) -> Vec<Edit<ExcerptDimension<MultiBufferOffset>>> {
6808        let mut excerpt_edits = Vec::new();
6809        for locator in &buffer_state.excerpts {
6810            let mut cursor = self
6811                .excerpts
6812                .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
6813            cursor.seek_forward(&Some(locator), Bias::Left);
6814            if let Some(excerpt) = cursor.item()
6815                && excerpt.locator == *locator
6816            {
6817                let excerpt_buffer_range = excerpt.range.context.to_offset(&excerpt.buffer);
6818                if diff_change_range.end < excerpt_buffer_range.start
6819                    || diff_change_range.start > excerpt_buffer_range.end
6820                {
6821                    continue;
6822                }
6823                let excerpt_start = cursor.start().1;
6824                let excerpt_len = excerpt.text_summary.len;
6825                let diff_change_start_in_excerpt = diff_change_range
6826                    .start
6827                    .saturating_sub(excerpt_buffer_range.start);
6828                let diff_change_end_in_excerpt = diff_change_range
6829                    .end
6830                    .saturating_sub(excerpt_buffer_range.start);
6831                let edit_start = excerpt_start + diff_change_start_in_excerpt.min(excerpt_len);
6832                let edit_end = excerpt_start + diff_change_end_in_excerpt.min(excerpt_len);
6833                excerpt_edits.push(Edit {
6834                    old: edit_start..edit_end,
6835                    new: edit_start..edit_end,
6836                });
6837            }
6838        }
6839        excerpt_edits
6840    }
6841}
6842
6843#[cfg(any(test, feature = "test-support"))]
6844impl MultiBufferSnapshot {
6845    pub fn random_byte_range(
6846        &self,
6847        start_offset: MultiBufferOffset,
6848        rng: &mut impl rand::Rng,
6849    ) -> Range<MultiBufferOffset> {
6850        let end = self.clip_offset(rng.random_range(start_offset..=self.len()), Bias::Right);
6851        let start = self.clip_offset(rng.random_range(start_offset..=end), Bias::Right);
6852        start..end
6853    }
6854
6855    #[cfg(any(test, feature = "test-support"))]
6856    fn check_invariants(&self) {
6857        let excerpts = self.excerpts.items(());
6858        let excerpt_ids = self.excerpt_ids.items(());
6859
6860        for (ix, excerpt) in excerpts.iter().enumerate() {
6861            if ix == 0 {
6862                if excerpt.locator <= Locator::min() {
6863                    panic!("invalid first excerpt locator {:?}", excerpt.locator);
6864                }
6865            } else if excerpt.locator <= excerpts[ix - 1].locator {
6866                panic!("excerpts are out-of-order: {:?}", excerpts);
6867            }
6868        }
6869
6870        for (ix, entry) in excerpt_ids.iter().enumerate() {
6871            if ix == 0 {
6872                if entry.id.cmp(&ExcerptId::min(), self).is_le() {
6873                    panic!("invalid first excerpt id {:?}", entry.id);
6874                }
6875            } else if entry.id <= excerpt_ids[ix - 1].id {
6876                panic!("excerpt ids are out-of-order: {:?}", excerpt_ids);
6877            }
6878        }
6879
6880        if self.diff_transforms.summary().input != self.excerpts.summary().text {
6881            panic!(
6882                "incorrect input summary. expected {:?}, got {:?}. transforms: {:+?}",
6883                self.excerpts.summary().text,
6884                self.diff_transforms.summary().input,
6885                self.diff_transforms.items(()),
6886            );
6887        }
6888
6889        let mut prev_transform: Option<&DiffTransform> = None;
6890        for item in self.diff_transforms.iter() {
6891            if let DiffTransform::BufferContent {
6892                summary,
6893                inserted_hunk_info,
6894            } = item
6895            {
6896                if let Some(DiffTransform::BufferContent {
6897                    inserted_hunk_info: prev_inserted_hunk_info,
6898                    ..
6899                }) = prev_transform
6900                    && *inserted_hunk_info == *prev_inserted_hunk_info
6901                {
6902                    panic!(
6903                        "multiple adjacent buffer content transforms with is_inserted_hunk = {inserted_hunk_info:?}. transforms: {:+?}",
6904                        self.diff_transforms.items(())
6905                    );
6906                }
6907                if summary.len == MultiBufferOffset(0) && !self.is_empty() {
6908                    panic!("empty buffer content transform");
6909                }
6910            }
6911            prev_transform = Some(item);
6912        }
6913    }
6914}
6915
6916impl<'a, MBD, BD> MultiBufferCursor<'a, MBD, BD>
6917where
6918    MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
6919    BD: TextDimension + AddAssign<<MBD as Sub>::Output>,
6920{
6921    #[instrument(skip_all)]
6922    fn seek(&mut self, position: &MBD) {
6923        let position = OutputDimension(*position);
6924        self.cached_region.take();
6925        self.diff_transforms.seek(&position, Bias::Right);
6926        if self.diff_transforms.item().is_none()
6927            && self.diff_transforms.start().output_dimension == position
6928        {
6929            self.diff_transforms.prev();
6930        }
6931
6932        let mut excerpt_position = self.diff_transforms.start().excerpt_dimension;
6933        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
6934            let overshoot = position - self.diff_transforms.start().output_dimension;
6935            excerpt_position += overshoot;
6936        }
6937
6938        self.excerpts.seek(&excerpt_position, Bias::Right);
6939        if self.excerpts.item().is_none() && excerpt_position == *self.excerpts.start() {
6940            self.excerpts.prev();
6941        }
6942    }
6943
6944    fn seek_forward(&mut self, position: &MBD) {
6945        let position = OutputDimension(*position);
6946        self.cached_region.take();
6947        self.diff_transforms.seek_forward(&position, Bias::Right);
6948        if self.diff_transforms.item().is_none()
6949            && self.diff_transforms.start().output_dimension == position
6950        {
6951            self.diff_transforms.prev();
6952        }
6953
6954        let overshoot = position - self.diff_transforms.start().output_dimension;
6955        let mut excerpt_position = self.diff_transforms.start().excerpt_dimension;
6956        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
6957            excerpt_position += overshoot;
6958        }
6959
6960        self.excerpts.seek_forward(&excerpt_position, Bias::Right);
6961        if self.excerpts.item().is_none() && excerpt_position == *self.excerpts.start() {
6962            self.excerpts.prev();
6963        }
6964    }
6965
6966    fn next_excerpt(&mut self) {
6967        self.excerpts.next();
6968        self.seek_to_start_of_current_excerpt();
6969    }
6970
6971    fn prev_excerpt(&mut self) {
6972        self.excerpts.prev();
6973        self.seek_to_start_of_current_excerpt();
6974    }
6975
6976    fn seek_to_start_of_current_excerpt(&mut self) {
6977        self.cached_region.take();
6978
6979        if self.diff_transforms.seek(self.excerpts.start(), Bias::Left)
6980            && self.diff_transforms.start().excerpt_dimension < *self.excerpts.start()
6981            && self.diff_transforms.next_item().is_some()
6982        {
6983            self.diff_transforms.next();
6984        }
6985    }
6986
6987    fn next_excerpt_forwards(&mut self) {
6988        self.excerpts.next();
6989        self.seek_to_start_of_current_excerpt_forward();
6990    }
6991
6992    fn seek_to_start_of_current_excerpt_forward(&mut self) {
6993        self.cached_region.take();
6994
6995        if self
6996            .diff_transforms
6997            .seek_forward(self.excerpts.start(), Bias::Left)
6998            && self.diff_transforms.start().excerpt_dimension < *self.excerpts.start()
6999            && self.diff_transforms.next_item().is_some()
7000        {
7001            self.diff_transforms.next();
7002        }
7003    }
7004
7005    fn next(&mut self) {
7006        self.cached_region.take();
7007        match self
7008            .diff_transforms
7009            .end()
7010            .excerpt_dimension
7011            .cmp(&self.excerpts.end())
7012        {
7013            cmp::Ordering::Less => self.diff_transforms.next(),
7014            cmp::Ordering::Greater => self.excerpts.next(),
7015            cmp::Ordering::Equal => {
7016                self.diff_transforms.next();
7017                if self.diff_transforms.end().excerpt_dimension > self.excerpts.end()
7018                    || self.diff_transforms.item().is_none()
7019                {
7020                    self.excerpts.next();
7021                } else if let Some(DiffTransform::DeletedHunk { hunk_info, .. }) =
7022                    self.diff_transforms.item()
7023                    && self
7024                        .excerpts
7025                        .item()
7026                        .is_some_and(|excerpt| excerpt.id != hunk_info.excerpt_id)
7027                {
7028                    self.excerpts.next();
7029                }
7030            }
7031        }
7032    }
7033
7034    fn prev(&mut self) {
7035        self.cached_region.take();
7036        match self
7037            .diff_transforms
7038            .start()
7039            .excerpt_dimension
7040            .cmp(self.excerpts.start())
7041        {
7042            cmp::Ordering::Less => self.excerpts.prev(),
7043            cmp::Ordering::Greater => self.diff_transforms.prev(),
7044            cmp::Ordering::Equal => {
7045                self.diff_transforms.prev();
7046                if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start()
7047                    || self.diff_transforms.item().is_none()
7048                {
7049                    self.excerpts.prev();
7050                }
7051            }
7052        }
7053    }
7054
7055    fn region(&self) -> Option<&MultiBufferRegion<'a, MBD, BD>> {
7056        self.cached_region
7057            .get_or_init(|| self.build_region())
7058            .as_ref()
7059    }
7060
7061    fn is_at_start_of_excerpt(&mut self) -> bool {
7062        if self.diff_transforms.start().excerpt_dimension > *self.excerpts.start() {
7063            return false;
7064        } else if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start() {
7065            return true;
7066        }
7067
7068        self.diff_transforms.prev();
7069        let prev_transform = self.diff_transforms.item();
7070        self.diff_transforms.next();
7071
7072        prev_transform.is_none_or(|next_transform| {
7073            matches!(next_transform, DiffTransform::BufferContent { .. })
7074        })
7075    }
7076
7077    fn is_at_end_of_excerpt(&self) -> bool {
7078        if self.diff_transforms.end().excerpt_dimension < self.excerpts.end() {
7079            return false;
7080        } else if self.diff_transforms.end().excerpt_dimension > self.excerpts.end()
7081            || self.diff_transforms.item().is_none()
7082        {
7083            return true;
7084        }
7085
7086        let next_transform = self.diff_transforms.next_item();
7087        next_transform.is_none_or(|next_transform| match next_transform {
7088            DiffTransform::BufferContent { .. } => true,
7089            DiffTransform::DeletedHunk { hunk_info, .. } => self
7090                .excerpts
7091                .item()
7092                .is_some_and(|excerpt| excerpt.id != hunk_info.excerpt_id),
7093        })
7094    }
7095
7096    fn main_buffer_position(&self) -> Option<BD> {
7097        let excerpt = self.excerpts.item()?;
7098        let buffer = &excerpt.buffer;
7099        let buffer_context_start = excerpt.range.context.start.summary::<BD>(buffer);
7100        let mut buffer_start = buffer_context_start;
7101        let overshoot = self.diff_transforms.end().excerpt_dimension - *self.excerpts.start();
7102        buffer_start += overshoot;
7103        Some(buffer_start)
7104    }
7105
7106    fn build_region(&self) -> Option<MultiBufferRegion<'a, MBD, BD>> {
7107        let excerpt = self.excerpts.item()?;
7108        match self.diff_transforms.item()? {
7109            DiffTransform::DeletedHunk {
7110                buffer_id,
7111                base_text_byte_range,
7112                has_trailing_newline,
7113                hunk_info,
7114                ..
7115            } => {
7116                let diff = self.diffs.get(buffer_id)?;
7117                let buffer = diff.base_text();
7118                let mut rope_cursor = buffer.as_rope().cursor(0);
7119                let buffer_start = rope_cursor.summary::<BD>(base_text_byte_range.start);
7120                let buffer_range_len = rope_cursor.summary::<BD>(base_text_byte_range.end);
7121                let mut buffer_end = buffer_start;
7122                TextDimension::add_assign(&mut buffer_end, &buffer_range_len);
7123                let start = self.diff_transforms.start().output_dimension.0;
7124                let end = self.diff_transforms.end().output_dimension.0;
7125                Some(MultiBufferRegion {
7126                    buffer,
7127                    excerpt,
7128                    has_trailing_newline: *has_trailing_newline,
7129                    is_main_buffer: false,
7130                    diff_hunk_status: Some(DiffHunkStatus::deleted(
7131                        hunk_info.hunk_secondary_status,
7132                    )),
7133                    buffer_range: buffer_start..buffer_end,
7134                    range: start..end,
7135                })
7136            }
7137            DiffTransform::BufferContent {
7138                inserted_hunk_info, ..
7139            } => {
7140                let buffer = &excerpt.buffer;
7141                let buffer_context_start = excerpt.range.context.start.summary::<BD>(buffer);
7142
7143                let mut start = self.diff_transforms.start().output_dimension.0;
7144                let mut buffer_start = buffer_context_start;
7145                if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start() {
7146                    let overshoot =
7147                        *self.excerpts.start() - self.diff_transforms.start().excerpt_dimension;
7148                    start += overshoot;
7149                } else {
7150                    let overshoot =
7151                        self.diff_transforms.start().excerpt_dimension - *self.excerpts.start();
7152                    buffer_start += overshoot;
7153                }
7154
7155                let mut end;
7156                let mut buffer_end;
7157                let has_trailing_newline;
7158                let transform_end = self.diff_transforms.end();
7159                if transform_end.excerpt_dimension < self.excerpts.end() {
7160                    let overshoot = transform_end.excerpt_dimension - *self.excerpts.start();
7161                    end = transform_end.output_dimension.0;
7162                    buffer_end = buffer_context_start;
7163                    buffer_end += overshoot;
7164                    has_trailing_newline = false;
7165                } else {
7166                    let overshoot =
7167                        self.excerpts.end() - self.diff_transforms.start().excerpt_dimension;
7168                    end = self.diff_transforms.start().output_dimension.0;
7169                    end += overshoot;
7170                    buffer_end = excerpt.range.context.end.summary::<BD>(buffer);
7171                    has_trailing_newline = excerpt.has_trailing_newline;
7172                };
7173
7174                let diff_hunk_status = inserted_hunk_info.map(|info| {
7175                    if info.is_logically_deleted {
7176                        DiffHunkStatus::deleted(info.hunk_secondary_status)
7177                    } else {
7178                        DiffHunkStatus::added(info.hunk_secondary_status)
7179                    }
7180                });
7181
7182                Some(MultiBufferRegion {
7183                    buffer,
7184                    excerpt,
7185                    has_trailing_newline,
7186                    is_main_buffer: true,
7187                    diff_hunk_status,
7188                    buffer_range: buffer_start..buffer_end,
7189                    range: start..end,
7190                })
7191            }
7192        }
7193    }
7194
7195    fn fetch_excerpt_with_range(&self) -> Option<(&'a Excerpt, Range<MBD>)> {
7196        let excerpt = self.excerpts.item()?;
7197        match self.diff_transforms.item()? {
7198            &DiffTransform::DeletedHunk { .. } => {
7199                let start = self.diff_transforms.start().output_dimension.0;
7200                let end = self.diff_transforms.end().output_dimension.0;
7201                Some((excerpt, start..end))
7202            }
7203            DiffTransform::BufferContent { .. } => {
7204                let mut start = self.diff_transforms.start().output_dimension.0;
7205                if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start() {
7206                    let overshoot =
7207                        *self.excerpts.start() - self.diff_transforms.start().excerpt_dimension;
7208                    start += overshoot;
7209                }
7210
7211                let mut end;
7212                let transform_end = self.diff_transforms.end();
7213                if transform_end.excerpt_dimension < self.excerpts.end() {
7214                    end = transform_end.output_dimension.0;
7215                } else {
7216                    let overshoot =
7217                        self.excerpts.end() - self.diff_transforms.start().excerpt_dimension;
7218                    end = self.diff_transforms.start().output_dimension.0;
7219                    end += overshoot;
7220                };
7221
7222                Some((excerpt, start..end))
7223            }
7224        }
7225    }
7226
7227    fn excerpt(&self) -> Option<&'a Excerpt> {
7228        self.excerpts.item()
7229    }
7230}
7231
7232impl Excerpt {
7233    fn new(
7234        path_key: PathKey,
7235        buffer: Arc<BufferSnapshot>,
7236        range: ExcerptRange<text::Anchor>,
7237        has_trailing_newline: bool,
7238    ) -> Self {
7239        Excerpt {
7240            path_key,
7241            max_buffer_row: range.context.end.to_point(&buffer).row,
7242            text_summary: buffer
7243                .text_summary_for_range::<TextSummary, _>(range.context.to_offset(&buffer)),
7244            buffer,
7245            range,
7246            has_trailing_newline,
7247        }
7248    }
7249
7250    fn chunks_in_range(&self, range: Range<usize>, language_aware: bool) -> ExcerptChunks<'_> {
7251        let content_start = self.range.context.start.to_offset(&self.buffer);
7252        let chunks_start = content_start + range.start;
7253        let chunks_end = content_start + cmp::min(range.end, self.text_summary.len);
7254
7255        let has_footer = self.has_trailing_newline
7256            && range.start <= self.text_summary.len
7257            && range.end > self.text_summary.len;
7258
7259        let content_chunks = self.buffer.chunks(chunks_start..chunks_end, language_aware);
7260
7261        ExcerptChunks {
7262            content_chunks,
7263            has_footer,
7264        }
7265    }
7266
7267    fn seek_chunks(&self, excerpt_chunks: &mut ExcerptChunks, range: Range<usize>) {
7268        let content_start = self.range.context.start.to_offset(&self.buffer);
7269        let chunks_start = content_start + range.start;
7270        let chunks_end = content_start + cmp::min(range.end, self.text_summary.len);
7271        excerpt_chunks.content_chunks.seek(chunks_start..chunks_end);
7272        excerpt_chunks.has_footer = self.has_trailing_newline
7273            && range.start <= self.text_summary.len
7274            && range.end > self.text_summary.len;
7275    }
7276
7277    fn clip_anchor(&self, text_anchor: text::Anchor) -> text::Anchor {
7278        if text_anchor
7279            .cmp(&self.range.context.start, &self.buffer)
7280            .is_lt()
7281        {
7282            self.range.context.start
7283        } else if text_anchor
7284            .cmp(&self.range.context.end, &self.buffer)
7285            .is_gt()
7286        {
7287            self.range.context.end
7288        } else {
7289            text_anchor
7290        }
7291    }
7292
7293    fn contains(&self, anchor: &Anchor) -> bool {
7294        (anchor.text_anchor.buffer_id == None
7295            || anchor.text_anchor.buffer_id == Some(self.buffer_id))
7296            && self
7297                .range
7298                .context
7299                .start
7300                .cmp(&anchor.text_anchor, &self.buffer)
7301                .is_le()
7302            && self
7303                .range
7304                .context
7305                .end
7306                .cmp(&anchor.text_anchor, &self.buffer)
7307                .is_ge()
7308    }
7309
7310    /// The [`Excerpt`]'s start offset in its [`Buffer`]
7311    fn buffer_start_offset(&self) -> BufferOffset {
7312        BufferOffset(self.range.context.start.to_offset(&self.buffer))
7313    }
7314
7315    /// The [`Excerpt`]'s end offset in its [`Buffer`]
7316    fn buffer_end_offset(&self) -> BufferOffset {
7317        self.buffer_start_offset() + self.text_summary.len
7318    }
7319}
7320
7321impl PartialEq for Excerpt {
7322    fn eq(&self, other: &Self) -> bool {
7323        self.buffer.remote_id() == other.buffer.remote_id()
7324            && self.range.context == other.range.context
7325    }
7326}
7327
7328impl<'a> MultiBufferExcerpt<'a> {
7329    pub fn id(&self) -> ExcerptId {
7330        self.excerpt.id
7331    }
7332
7333    pub fn buffer_id(&self) -> BufferId {
7334        self.excerpt.buffer_id
7335    }
7336
7337    pub fn start_anchor(&self) -> Anchor {
7338        Anchor::text(self.excerpt.id, self.excerpt.range.context.start)
7339    }
7340
7341    pub fn end_anchor(&self) -> Anchor {
7342        Anchor::text(self.excerpt.id, self.excerpt.range.context.end)
7343    }
7344
7345    pub fn buffer(&self) -> &'a BufferSnapshot {
7346        &self.excerpt.buffer
7347    }
7348
7349    pub fn buffer_range(&self) -> Range<BufferOffset> {
7350        self.buffer_offset
7351            ..BufferOffset(
7352                self.excerpt
7353                    .range
7354                    .context
7355                    .end
7356                    .to_offset(&self.excerpt.buffer.text),
7357            )
7358    }
7359
7360    pub fn start_offset(&self) -> MultiBufferOffset {
7361        self.offset
7362    }
7363
7364    /// Maps an offset within the [`MultiBuffer`] to an offset within the [`Buffer`]
7365    pub fn map_offset_to_buffer(&mut self, offset: MultiBufferOffset) -> BufferOffset {
7366        self.map_range_to_buffer(offset..offset).start
7367    }
7368
7369    /// Maps a range within the [`MultiBuffer`] to a range within the [`Buffer`]
7370    pub fn map_range_to_buffer(&mut self, range: Range<MultiBufferOffset>) -> Range<BufferOffset> {
7371        self.diff_transforms
7372            .seek(&OutputDimension(range.start), Bias::Right);
7373        let start = self.map_offset_to_buffer_internal(range.start);
7374        let end = if range.end > range.start {
7375            self.diff_transforms
7376                .seek_forward(&OutputDimension(range.end), Bias::Right);
7377            self.map_offset_to_buffer_internal(range.end)
7378        } else {
7379            start
7380        };
7381        start..end
7382    }
7383
7384    fn map_offset_to_buffer_internal(&self, offset: MultiBufferOffset) -> BufferOffset {
7385        let mut excerpt_offset = self.diff_transforms.start().excerpt_dimension;
7386        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7387            excerpt_offset += offset - self.diff_transforms.start().output_dimension.0;
7388        };
7389        let offset_in_excerpt = excerpt_offset.saturating_sub(self.excerpt_offset);
7390        self.buffer_offset + offset_in_excerpt
7391    }
7392
7393    /// Map an offset within the [`Buffer`] to an offset within the [`MultiBuffer`]
7394    pub fn map_offset_from_buffer(&mut self, buffer_offset: BufferOffset) -> MultiBufferOffset {
7395        self.map_range_from_buffer(buffer_offset..buffer_offset)
7396            .start
7397    }
7398
7399    /// Map a range within the [`Buffer`] to a range within the [`MultiBuffer`]
7400    pub fn map_range_from_buffer(
7401        &mut self,
7402        buffer_range: Range<BufferOffset>,
7403    ) -> Range<MultiBufferOffset> {
7404        if buffer_range.start < self.buffer_offset {
7405            log::warn!(
7406                "Attempting to map a range from a buffer offset that starts before the current buffer offset"
7407            );
7408            return self.offset..self.offset;
7409        }
7410        let overshoot = buffer_range.start - self.buffer_offset;
7411        let excerpt_offset = self.excerpt_offset + overshoot;
7412        let excerpt_seek_dim = excerpt_offset;
7413        self.diff_transforms.seek(&excerpt_seek_dim, Bias::Right);
7414        if self.diff_transforms.start().excerpt_dimension > excerpt_offset {
7415            log::warn!(
7416                "Attempting to map a range from a buffer offset that starts before the current buffer offset"
7417            );
7418            return self.offset..self.offset;
7419        }
7420        let overshoot = excerpt_offset - self.diff_transforms.start().excerpt_dimension;
7421        let start = self.diff_transforms.start().output_dimension.0 + overshoot;
7422
7423        let end = if buffer_range.start < buffer_range.end {
7424            let overshoot = buffer_range.end - self.buffer_offset;
7425            let excerpt_offset = self.excerpt_offset + overshoot;
7426            let excerpt_seek_dim = excerpt_offset;
7427            self.diff_transforms
7428                .seek_forward(&excerpt_seek_dim, Bias::Right);
7429            let overshoot = excerpt_offset - self.diff_transforms.start().excerpt_dimension;
7430            // todo(lw): Clamp end to the excerpt boundaries
7431            self.diff_transforms.start().output_dimension.0 + overshoot
7432        } else {
7433            start
7434        };
7435
7436        start..end
7437    }
7438
7439    /// Returns true if the entirety of the given range is in the buffer's excerpt
7440    pub fn contains_buffer_range(&self, range: Range<BufferOffset>) -> bool {
7441        range.start >= self.excerpt.buffer_start_offset()
7442            && range.end <= self.excerpt.buffer_end_offset()
7443    }
7444
7445    /// Returns true if any part of the given range is in the buffer's excerpt
7446    pub fn contains_partial_buffer_range(&self, range: Range<BufferOffset>) -> bool {
7447        range.start <= self.excerpt.buffer_end_offset()
7448            && range.end >= self.excerpt.buffer_start_offset()
7449    }
7450
7451    pub fn max_buffer_row(&self) -> u32 {
7452        self.excerpt.max_buffer_row
7453    }
7454}
7455
7456impl fmt::Debug for Excerpt {
7457    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
7458        f.debug_struct("Excerpt")
7459            .field("path_key", &self.path_key)
7460            .field("range", &self.range)
7461            .field("text_summary", &self.text_summary)
7462            .field("has_trailing_newline", &self.has_trailing_newline)
7463            .finish()
7464    }
7465}
7466
7467impl sum_tree::Item for Excerpt {
7468    type Summary = ExcerptSummary;
7469
7470    fn summary(&self, _cx: ()) -> Self::Summary {
7471        let mut text = self.text_summary;
7472        if self.has_trailing_newline {
7473            text += TextSummary::from("\n");
7474        }
7475        ExcerptSummary {
7476            path_key: self.path_key,
7477            max_anchor: self.range.context.end,
7478            widest_line_number: self.max_buffer_row,
7479            text: text.into(),
7480            count: 1,
7481        }
7482    }
7483}
7484
7485impl DiffTransform {
7486    fn hunk_info(&self) -> Option<DiffTransformHunkInfo> {
7487        match self {
7488            DiffTransform::DeletedHunk { hunk_info, .. } => Some(*hunk_info),
7489            DiffTransform::BufferContent {
7490                inserted_hunk_info, ..
7491            } => *inserted_hunk_info,
7492        }
7493    }
7494}
7495
7496impl sum_tree::Item for DiffTransform {
7497    type Summary = DiffTransformSummary;
7498
7499    fn summary(&self, _: <Self::Summary as sum_tree::Summary>::Context<'_>) -> Self::Summary {
7500        match self {
7501            DiffTransform::BufferContent { summary, .. } => DiffTransformSummary {
7502                input: *summary,
7503                output: *summary,
7504            },
7505            &DiffTransform::DeletedHunk { summary, .. } => DiffTransformSummary {
7506                input: MBTextSummary::default(),
7507                output: summary.into(),
7508            },
7509        }
7510    }
7511}
7512
7513impl DiffTransformSummary {
7514    fn excerpt_len(&self) -> ExcerptOffset {
7515        ExcerptDimension(self.input.len)
7516    }
7517}
7518
7519impl sum_tree::ContextLessSummary for DiffTransformSummary {
7520    fn zero() -> Self {
7521        DiffTransformSummary {
7522            input: MBTextSummary::default(),
7523            output: MBTextSummary::default(),
7524        }
7525    }
7526
7527    fn add_summary(&mut self, other: &Self) {
7528        self.input += other.input;
7529        self.output += other.output;
7530    }
7531}
7532
7533impl sum_tree::Dimension<'_, ExcerptSummary> for PathKey {
7534    fn zero(_: <ExcerptSummary as sum_tree::Summary>::Context<'_>) -> Self {
7535        PathKey::min()
7536    }
7537
7538    fn add_summary(
7539        &mut self,
7540        summary: &'_ ExcerptSummary,
7541        _cx: <ExcerptSummary as sum_tree::Summary>::Context<'_>,
7542    ) {
7543        *self = summary.path_key.clone();
7544    }
7545}
7546
7547impl sum_tree::ContextLessSummary for ExcerptSummary {
7548    fn zero() -> Self {
7549        Self::min()
7550    }
7551
7552    fn add_summary(&mut self, summary: &Self) {
7553        debug_assert!(
7554            summary.path_key >= self.path_key,
7555            "Path keys must be in ascending order: {:?} > {:?}",
7556            summary.path_key,
7557            self.path_key
7558        );
7559
7560        self.path_key = summary.path_key.clone();
7561        self.max_anchor = summary.max_anchor;
7562        self.text += summary.text;
7563        self.widest_line_number = cmp::max(self.widest_line_number, summary.widest_line_number);
7564        self.count += summary.count;
7565    }
7566}
7567
7568// todo!() should this take a lifetime?
7569enum AnchorSeekTarget {
7570    Min,
7571    Max,
7572    Text {
7573        path_key: PathKey,
7574        anchor: text::Anchor,
7575        snapshot: BufferSnapshot,
7576    },
7577}
7578
7579impl sum_tree::SeekTarget<'_, ExcerptSummary, ExcerptSummary> for AnchorSeekTarget {
7580    fn cmp(
7581        &self,
7582        cursor_location: &ExcerptSummary,
7583        _cx: <ExcerptSummary as sum_tree::Summary>::Context<'_>,
7584    ) -> cmp::Ordering {
7585        match self {
7586            AnchorSeekTarget::Min => Ordering::Less,
7587            AnchorSeekTarget::Max => Ordering::Greater,
7588            AnchorSeekTarget::Text {
7589                path_key,
7590                anchor,
7591                snapshot,
7592            } => Ord::cmp(path_key, &cursor_location.path_key)
7593                .then_with(|| anchor.cmp(&cursor_location.max_anchor, snapshot)),
7594        }
7595    }
7596}
7597
7598impl<'a, MBD> sum_tree::Dimension<'a, ExcerptSummary> for ExcerptDimension<MBD>
7599where
7600    MBD: MultiBufferDimension + Default,
7601{
7602    fn zero(_: ()) -> Self {
7603        ExcerptDimension(MBD::default())
7604    }
7605
7606    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: ()) {
7607        MultiBufferDimension::add_mb_text_summary(&mut self.0, &summary.text)
7608    }
7609}
7610
7611#[derive(Copy, Clone, PartialOrd, Ord, Eq, PartialEq, Debug)]
7612struct OutputDimension<T>(T);
7613
7614impl<T: PartialEq> PartialEq<T> for OutputDimension<T> {
7615    fn eq(&self, other: &T) -> bool {
7616        self.0 == *other
7617    }
7618}
7619
7620impl<T: PartialOrd> PartialOrd<T> for OutputDimension<T> {
7621    fn partial_cmp(&self, other: &T) -> Option<cmp::Ordering> {
7622        self.0.partial_cmp(other)
7623    }
7624}
7625
7626impl<R, T, U> ops::Sub<OutputDimension<U>> for OutputDimension<T>
7627where
7628    T: ops::Sub<U, Output = R>,
7629{
7630    type Output = R;
7631
7632    fn sub(self, other: OutputDimension<U>) -> Self::Output {
7633        self.0 - other.0
7634    }
7635}
7636
7637impl<R, T, U> ops::Add<U> for OutputDimension<T>
7638where
7639    T: ops::Add<U, Output = R>,
7640{
7641    type Output = OutputDimension<R>;
7642
7643    fn add(self, other: U) -> Self::Output {
7644        OutputDimension(self.0 + other)
7645    }
7646}
7647
7648impl<T, U> AddAssign<U> for OutputDimension<T>
7649where
7650    T: AddAssign<U>,
7651{
7652    fn add_assign(&mut self, other: U) {
7653        self.0 += other;
7654    }
7655}
7656
7657impl<T, U> SubAssign<U> for OutputDimension<T>
7658where
7659    T: SubAssign<U>,
7660{
7661    fn sub_assign(&mut self, other: U) {
7662        self.0 -= other;
7663    }
7664}
7665
7666#[derive(Copy, Clone, PartialOrd, Ord, Eq, PartialEq, Debug)]
7667struct ExcerptDimension<T>(T);
7668
7669impl<T: PartialEq> PartialEq<T> for ExcerptDimension<T> {
7670    fn eq(&self, other: &T) -> bool {
7671        self.0 == *other
7672    }
7673}
7674
7675impl<T: PartialOrd> PartialOrd<T> for ExcerptDimension<T> {
7676    fn partial_cmp(&self, other: &T) -> Option<cmp::Ordering> {
7677        self.0.partial_cmp(other)
7678    }
7679}
7680
7681impl ExcerptOffset {
7682    fn saturating_sub(self, other: ExcerptOffset) -> usize {
7683        self.0.saturating_sub(other.0)
7684    }
7685}
7686
7687impl<R, T, U> ops::Sub<ExcerptDimension<U>> for ExcerptDimension<T>
7688where
7689    T: ops::Sub<U, Output = R>,
7690{
7691    type Output = R;
7692
7693    fn sub(self, other: ExcerptDimension<U>) -> Self::Output {
7694        self.0 - other.0
7695    }
7696}
7697
7698impl<R, T, U> ops::Add<U> for ExcerptDimension<T>
7699where
7700    T: ops::Add<U, Output = R>,
7701{
7702    type Output = ExcerptDimension<R>;
7703
7704    fn add(self, other: U) -> Self::Output {
7705        ExcerptDimension(self.0 + other)
7706    }
7707}
7708
7709impl<T, U> AddAssign<U> for ExcerptDimension<T>
7710where
7711    T: AddAssign<U>,
7712{
7713    fn add_assign(&mut self, other: U) {
7714        self.0 += other;
7715    }
7716}
7717
7718impl<T, U> SubAssign<U> for ExcerptDimension<T>
7719where
7720    T: SubAssign<U>,
7721{
7722    fn sub_assign(&mut self, other: U) {
7723        self.0 -= other;
7724    }
7725}
7726
7727impl<'a> sum_tree::Dimension<'a, DiffTransformSummary> for MultiBufferOffset {
7728    fn zero(_: ()) -> Self {
7729        MultiBufferOffset::ZERO
7730    }
7731
7732    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7733        *self += summary.output.len;
7734    }
7735}
7736
7737impl<MBD> sum_tree::SeekTarget<'_, DiffTransformSummary, DiffTransformSummary>
7738    for ExcerptDimension<MBD>
7739where
7740    MBD: MultiBufferDimension + Ord,
7741{
7742    fn cmp(&self, cursor_location: &DiffTransformSummary, _: ()) -> cmp::Ordering {
7743        Ord::cmp(&self.0, &MBD::from_summary(&cursor_location.input))
7744    }
7745}
7746
7747impl<'a, MBD> sum_tree::SeekTarget<'a, DiffTransformSummary, DiffTransforms<MBD>>
7748    for ExcerptDimension<MBD>
7749where
7750    MBD: MultiBufferDimension + Ord,
7751{
7752    fn cmp(&self, cursor_location: &DiffTransforms<MBD>, _: ()) -> cmp::Ordering {
7753        Ord::cmp(&self.0, &cursor_location.excerpt_dimension.0)
7754    }
7755}
7756
7757impl<'a, MBD: MultiBufferDimension> sum_tree::Dimension<'a, DiffTransformSummary>
7758    for ExcerptDimension<MBD>
7759{
7760    fn zero(_: ()) -> Self {
7761        ExcerptDimension(MBD::default())
7762    }
7763
7764    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7765        self.0.add_mb_text_summary(&summary.input)
7766    }
7767}
7768
7769impl<'a, MBD> sum_tree::SeekTarget<'a, DiffTransformSummary, DiffTransforms<MBD>>
7770    for OutputDimension<MBD>
7771where
7772    MBD: MultiBufferDimension + Ord,
7773{
7774    fn cmp(&self, cursor_location: &DiffTransforms<MBD>, _: ()) -> cmp::Ordering {
7775        Ord::cmp(&self.0, &cursor_location.output_dimension.0)
7776    }
7777}
7778
7779impl<'a, MBD: MultiBufferDimension> sum_tree::Dimension<'a, DiffTransformSummary>
7780    for OutputDimension<MBD>
7781{
7782    fn zero(_: ()) -> Self {
7783        OutputDimension(MBD::default())
7784    }
7785
7786    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7787        self.0.add_mb_text_summary(&summary.output)
7788    }
7789}
7790
7791impl MultiBufferRows<'_> {
7792    pub fn seek(&mut self, MultiBufferRow(row): MultiBufferRow) {
7793        self.point = Point::new(row, 0);
7794        self.cursor.seek(&self.point);
7795    }
7796}
7797
7798impl Iterator for MultiBufferRows<'_> {
7799    type Item = RowInfo;
7800
7801    fn next(&mut self) -> Option<Self::Item> {
7802        if self.is_empty && self.point.row == 0 {
7803            self.point += Point::new(1, 0);
7804            return Some(RowInfo {
7805                buffer_id: None,
7806                buffer_row: Some(0),
7807                multibuffer_row: Some(MultiBufferRow(0)),
7808                diff_status: None,
7809                expand_info: None,
7810                wrapped_buffer_row: None,
7811            });
7812        }
7813
7814        let mut region = self.cursor.region()?.clone();
7815        while self.point >= region.range.end {
7816            self.cursor.next();
7817            if let Some(next_region) = self.cursor.region() {
7818                region = next_region.clone();
7819            } else if self.point == self.cursor.diff_transforms.end().output_dimension.0 {
7820                let multibuffer_row = MultiBufferRow(self.point.row);
7821                let last_excerpt = self
7822                    .cursor
7823                    .excerpts
7824                    .item()
7825                    .or(self.cursor.excerpts.prev_item())?;
7826                let last_row = last_excerpt
7827                    .range
7828                    .context
7829                    .end
7830                    .to_point(&last_excerpt.buffer)
7831                    .row;
7832
7833                let first_row = last_excerpt
7834                    .range
7835                    .context
7836                    .start
7837                    .to_point(&last_excerpt.buffer)
7838                    .row;
7839
7840                let expand_info = if self.is_singleton {
7841                    None
7842                } else {
7843                    let needs_expand_up = first_row == last_row
7844                        && last_row > 0
7845                        && !region.diff_hunk_status.is_some_and(|d| d.is_deleted());
7846                    let needs_expand_down = last_row < last_excerpt.buffer.max_point().row;
7847
7848                    if needs_expand_up && needs_expand_down {
7849                        Some(ExpandExcerptDirection::UpAndDown)
7850                    } else if needs_expand_up {
7851                        Some(ExpandExcerptDirection::Up)
7852                    } else if needs_expand_down {
7853                        Some(ExpandExcerptDirection::Down)
7854                    } else {
7855                        None
7856                    }
7857                    .map(|direction| ExpandInfo {
7858                        direction,
7859                        excerpt_id: last_excerpt.id,
7860                    })
7861                };
7862                self.point += Point::new(1, 0);
7863                return Some(RowInfo {
7864                    buffer_id: Some(last_excerpt.buffer_id),
7865                    buffer_row: Some(last_row),
7866                    multibuffer_row: Some(multibuffer_row),
7867                    diff_status: None,
7868                    wrapped_buffer_row: None,
7869                    expand_info,
7870                });
7871            } else {
7872                return None;
7873            };
7874        }
7875
7876        let overshoot = self.point - region.range.start;
7877        let buffer_point = region.buffer_range.start + overshoot;
7878        let expand_info = if self.is_singleton {
7879            None
7880        } else {
7881            let needs_expand_up = self.point.row == region.range.start.row
7882                && self.cursor.is_at_start_of_excerpt()
7883                && buffer_point.row > 0;
7884            let needs_expand_down = (region.excerpt.has_trailing_newline
7885                && self.point.row + 1 == region.range.end.row
7886                || !region.excerpt.has_trailing_newline && self.point.row == region.range.end.row)
7887                && self.cursor.is_at_end_of_excerpt()
7888                && buffer_point.row < region.buffer.max_point().row;
7889
7890            if needs_expand_up && needs_expand_down {
7891                Some(ExpandExcerptDirection::UpAndDown)
7892            } else if needs_expand_up {
7893                Some(ExpandExcerptDirection::Up)
7894            } else if needs_expand_down {
7895                Some(ExpandExcerptDirection::Down)
7896            } else {
7897                None
7898            }
7899            .map(|direction| ExpandInfo {
7900                direction,
7901                excerpt_id: region.excerpt.id,
7902            })
7903        };
7904
7905        let result = Some(RowInfo {
7906            buffer_id: Some(region.buffer.remote_id()),
7907            buffer_row: Some(buffer_point.row),
7908            multibuffer_row: Some(MultiBufferRow(self.point.row)),
7909            diff_status: region
7910                .diff_hunk_status
7911                .filter(|_| self.point < region.range.end),
7912            expand_info,
7913            wrapped_buffer_row: None,
7914        });
7915        self.point += Point::new(1, 0);
7916        result
7917    }
7918}
7919
7920impl<'a> MultiBufferChunks<'a> {
7921    pub fn offset(&self) -> MultiBufferOffset {
7922        self.range.start
7923    }
7924
7925    pub fn seek(&mut self, range: Range<MultiBufferOffset>) {
7926        self.diff_transforms.seek(&range.end, Bias::Right);
7927        let mut excerpt_end = self.diff_transforms.start().1;
7928        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7929            let overshoot = range.end - self.diff_transforms.start().0;
7930            excerpt_end += overshoot;
7931        }
7932
7933        self.diff_transforms.seek(&range.start, Bias::Right);
7934        let mut excerpt_start = self.diff_transforms.start().1;
7935        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7936            let overshoot = range.start - self.diff_transforms.start().0;
7937            excerpt_start += overshoot;
7938        }
7939
7940        self.seek_to_excerpt_offset_range(excerpt_start..excerpt_end);
7941        self.buffer_chunk.take();
7942        self.range = range;
7943    }
7944
7945    fn seek_to_excerpt_offset_range(&mut self, new_range: Range<ExcerptOffset>) {
7946        self.excerpt_offset_range = new_range.clone();
7947        self.excerpts.seek(&new_range.start, Bias::Right);
7948        if let Some(excerpt) = self.excerpts.item() {
7949            let excerpt_start = *self.excerpts.start();
7950            if let Some(excerpt_chunks) = self
7951                .excerpt_chunks
7952                .as_mut()
7953                .filter(|chunks| excerpt.id == chunks.excerpt_id)
7954            {
7955                excerpt.seek_chunks(
7956                    excerpt_chunks,
7957                    (self.excerpt_offset_range.start - excerpt_start)
7958                        ..(self.excerpt_offset_range.end - excerpt_start),
7959                );
7960            } else {
7961                self.excerpt_chunks = Some(excerpt.chunks_in_range(
7962                    (self.excerpt_offset_range.start - excerpt_start)
7963                        ..(self.excerpt_offset_range.end - excerpt_start),
7964                    self.language_aware,
7965                ));
7966            }
7967        } else {
7968            self.excerpt_chunks = None;
7969        }
7970    }
7971
7972    #[ztracing::instrument(skip_all)]
7973    fn next_excerpt_chunk(&mut self) -> Option<Chunk<'a>> {
7974        loop {
7975            if self.excerpt_offset_range.is_empty() {
7976                return None;
7977            } else if let Some(chunk) = self.excerpt_chunks.as_mut()?.next() {
7978                self.excerpt_offset_range.start += chunk.text.len();
7979                return Some(chunk);
7980            } else {
7981                self.excerpts.next();
7982                let excerpt = self.excerpts.item()?;
7983                self.excerpt_chunks = Some(excerpt.chunks_in_range(
7984                    0..(self.excerpt_offset_range.end - *self.excerpts.start()),
7985                    self.language_aware,
7986                ));
7987            }
7988        }
7989    }
7990}
7991
7992impl<'a> Iterator for ReversedMultiBufferChunks<'a> {
7993    type Item = &'a str;
7994
7995    fn next(&mut self) -> Option<Self::Item> {
7996        let mut region = self.cursor.region()?;
7997        if self.offset == region.range.start {
7998            self.cursor.prev();
7999            region = self.cursor.region()?;
8000            let start_overshoot = self.start.saturating_sub(region.range.start);
8001            self.current_chunks = Some(region.buffer.reversed_chunks_in_range(
8002                region.buffer_range.start + start_overshoot..region.buffer_range.end,
8003            ));
8004        }
8005
8006        if self.offset == region.range.end && region.has_trailing_newline {
8007            self.offset -= 1;
8008            Some("\n")
8009        } else {
8010            let chunk = self.current_chunks.as_mut().unwrap().next()?;
8011            self.offset -= chunk.len();
8012            Some(chunk)
8013        }
8014    }
8015}
8016
8017impl<'a> Iterator for MultiBufferChunks<'a> {
8018    type Item = Chunk<'a>;
8019
8020    #[ztracing::instrument(skip_all)]
8021    fn next(&mut self) -> Option<Chunk<'a>> {
8022        if self.range.start >= self.range.end {
8023            return None;
8024        }
8025        if self.range.start == self.diff_transforms.end().0 {
8026            self.diff_transforms.next();
8027        }
8028
8029        let diff_transform_start = self.diff_transforms.start().0;
8030        let diff_transform_end = self.diff_transforms.end().0;
8031        debug_assert!(
8032            self.range.start < diff_transform_end,
8033            "{:?} < {:?} of ({1:?}..{2:?})",
8034            self.range.start,
8035            diff_transform_end,
8036            diff_transform_start
8037        );
8038
8039        let diff_transform = self.diff_transforms.item()?;
8040        match diff_transform {
8041            DiffTransform::BufferContent { .. } => {
8042                let chunk = if let Some(chunk) = &mut self.buffer_chunk {
8043                    chunk
8044                } else {
8045                    let chunk = self.next_excerpt_chunk().unwrap();
8046                    self.buffer_chunk.insert(chunk)
8047                };
8048
8049                let chunk_end = self.range.start + chunk.text.len();
8050                let diff_transform_end = diff_transform_end.min(self.range.end);
8051
8052                if diff_transform_end < chunk_end {
8053                    let split_idx = diff_transform_end - self.range.start;
8054                    let (before, after) = chunk.text.split_at(split_idx);
8055                    self.range.start = diff_transform_end;
8056                    let mask = 1u128.unbounded_shl(split_idx as u32).wrapping_sub(1);
8057                    let chars = chunk.chars & mask;
8058                    let tabs = chunk.tabs & mask;
8059                    let newlines = chunk.newlines & mask;
8060
8061                    chunk.text = after;
8062                    chunk.chars = chunk.chars >> split_idx;
8063                    chunk.tabs = chunk.tabs >> split_idx;
8064                    chunk.newlines = chunk.newlines >> split_idx;
8065
8066                    Some(Chunk {
8067                        text: before,
8068                        chars,
8069                        tabs,
8070                        newlines,
8071                        ..chunk.clone()
8072                    })
8073                } else {
8074                    self.range.start = chunk_end;
8075                    self.buffer_chunk.take()
8076                }
8077            }
8078            DiffTransform::DeletedHunk {
8079                buffer_id,
8080                base_text_byte_range,
8081                has_trailing_newline,
8082                ..
8083            } => {
8084                let base_text_start =
8085                    base_text_byte_range.start + (self.range.start - diff_transform_start);
8086                let base_text_end =
8087                    base_text_byte_range.start + (self.range.end - diff_transform_start);
8088                let base_text_end = base_text_end.min(base_text_byte_range.end);
8089
8090                let mut chunks = if let Some((_, mut chunks)) = self
8091                    .diff_base_chunks
8092                    .take()
8093                    .filter(|(id, _)| id == buffer_id)
8094                {
8095                    if chunks.range().start != base_text_start || chunks.range().end < base_text_end
8096                    {
8097                        chunks.seek(base_text_start..base_text_end);
8098                    }
8099                    chunks
8100                } else {
8101                    let base_buffer = &self.diffs.get(buffer_id)?.base_text();
8102                    base_buffer.chunks(base_text_start..base_text_end, self.language_aware)
8103                };
8104
8105                let chunk = if let Some(chunk) = chunks.next() {
8106                    self.range.start += chunk.text.len();
8107                    self.diff_base_chunks = Some((*buffer_id, chunks));
8108                    chunk
8109                } else {
8110                    debug_assert!(has_trailing_newline);
8111                    self.range.start += "\n".len();
8112                    Chunk {
8113                        text: "\n",
8114                        chars: 1u128,
8115                        newlines: 1u128,
8116                        ..Default::default()
8117                    }
8118                };
8119                Some(chunk)
8120            }
8121        }
8122    }
8123}
8124
8125impl MultiBufferBytes<'_> {
8126    fn consume(&mut self, len: usize) {
8127        self.range.start += len;
8128        self.chunk = &self.chunk[len..];
8129
8130        if !self.range.is_empty() && self.chunk.is_empty() {
8131            if let Some(chunk) = self.excerpt_bytes.as_mut().and_then(|bytes| bytes.next()) {
8132                self.chunk = chunk;
8133            } else if self.has_trailing_newline {
8134                self.has_trailing_newline = false;
8135                self.chunk = b"\n";
8136            } else {
8137                self.cursor.next();
8138                if let Some(region) = self.cursor.region() {
8139                    let mut excerpt_bytes = region.buffer.bytes_in_range(
8140                        region.buffer_range.start
8141                            ..(region.buffer_range.start + (self.range.end - region.range.start))
8142                                .min(region.buffer_range.end),
8143                    );
8144                    self.chunk = excerpt_bytes.next().unwrap_or(&[]);
8145                    self.excerpt_bytes = Some(excerpt_bytes);
8146                    self.has_trailing_newline =
8147                        region.has_trailing_newline && self.range.end >= region.range.end;
8148                    if self.chunk.is_empty() && self.has_trailing_newline {
8149                        self.has_trailing_newline = false;
8150                        self.chunk = b"\n";
8151                    }
8152                }
8153            }
8154        }
8155    }
8156}
8157
8158impl<'a> Iterator for MultiBufferBytes<'a> {
8159    type Item = &'a [u8];
8160
8161    fn next(&mut self) -> Option<Self::Item> {
8162        let chunk = self.chunk;
8163        if chunk.is_empty() {
8164            None
8165        } else {
8166            self.consume(chunk.len());
8167            Some(chunk)
8168        }
8169    }
8170}
8171
8172impl io::Read for MultiBufferBytes<'_> {
8173    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
8174        let len = cmp::min(buf.len(), self.chunk.len());
8175        buf[..len].copy_from_slice(&self.chunk[..len]);
8176        if len > 0 {
8177            self.consume(len);
8178        }
8179        Ok(len)
8180    }
8181}
8182
8183impl io::Read for ReversedMultiBufferBytes<'_> {
8184    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
8185        let len = cmp::min(buf.len(), self.chunk.len());
8186        buf[..len].copy_from_slice(&self.chunk[..len]);
8187        buf[..len].reverse();
8188        if len > 0 {
8189            self.range.end -= len;
8190            self.chunk = &self.chunk[..self.chunk.len() - len];
8191            if !self.range.is_empty()
8192                && self.chunk.is_empty()
8193                && let Some(chunk) = self.chunks.next()
8194            {
8195                self.chunk = chunk.as_bytes();
8196            }
8197        }
8198        Ok(len)
8199    }
8200}
8201
8202impl<'a> Iterator for ExcerptChunks<'a> {
8203    type Item = Chunk<'a>;
8204
8205    fn next(&mut self) -> Option<Self::Item> {
8206        if let Some(chunk) = self.content_chunks.next() {
8207            return Some(chunk);
8208        }
8209
8210        if self.has_footer {
8211            let text = "\n";
8212            let chars = 0b1;
8213            let newlines = 0b1;
8214            self.has_footer = false;
8215            return Some(Chunk {
8216                text,
8217                chars,
8218                newlines,
8219                ..Default::default()
8220            });
8221        }
8222
8223        None
8224    }
8225}
8226
8227impl ToOffset for Point {
8228    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8229        snapshot.point_to_offset(*self)
8230    }
8231    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8232        snapshot.point_to_offset_utf16(*self)
8233    }
8234}
8235
8236impl ToOffset for MultiBufferOffset {
8237    #[track_caller]
8238    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8239        assert!(
8240            *self <= snapshot.len(),
8241            "offset {} is greater than the snapshot.len() {}",
8242            self.0,
8243            snapshot.len().0,
8244        );
8245        *self
8246    }
8247    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8248        snapshot.offset_to_offset_utf16(*self)
8249    }
8250}
8251
8252impl ToOffset for MultiBufferOffsetUtf16 {
8253    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8254        snapshot.offset_utf16_to_offset(*self)
8255    }
8256
8257    fn to_offset_utf16(&self, _snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8258        *self
8259    }
8260}
8261
8262impl ToOffset for PointUtf16 {
8263    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8264        snapshot.point_utf16_to_offset(*self)
8265    }
8266    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8267        snapshot.point_utf16_to_offset_utf16(*self)
8268    }
8269}
8270
8271impl ToPoint for MultiBufferOffset {
8272    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
8273        snapshot.offset_to_point(*self)
8274    }
8275    fn to_point_utf16<'a>(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16 {
8276        snapshot.offset_to_point_utf16(*self)
8277    }
8278}
8279
8280impl ToPoint for Point {
8281    fn to_point<'a>(&self, _: &MultiBufferSnapshot) -> Point {
8282        *self
8283    }
8284    fn to_point_utf16<'a>(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16 {
8285        snapshot.point_to_point_utf16(*self)
8286    }
8287}
8288
8289impl ToPoint for PointUtf16 {
8290    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
8291        snapshot.point_utf16_to_point(*self)
8292    }
8293    fn to_point_utf16<'a>(&self, _: &MultiBufferSnapshot) -> PointUtf16 {
8294        *self
8295    }
8296}
8297
8298#[cfg(debug_assertions)]
8299pub mod debug {
8300    use super::*;
8301
8302    pub trait ToMultiBufferDebugRanges {
8303        fn to_multi_buffer_debug_ranges(
8304            &self,
8305            snapshot: &MultiBufferSnapshot,
8306        ) -> Vec<Range<MultiBufferOffset>>;
8307    }
8308
8309    impl<T: ToOffset> ToMultiBufferDebugRanges for T {
8310        fn to_multi_buffer_debug_ranges(
8311            &self,
8312            snapshot: &MultiBufferSnapshot,
8313        ) -> Vec<Range<MultiBufferOffset>> {
8314            [self.to_offset(snapshot)].to_multi_buffer_debug_ranges(snapshot)
8315        }
8316    }
8317
8318    impl<T: ToOffset> ToMultiBufferDebugRanges for Range<T> {
8319        fn to_multi_buffer_debug_ranges(
8320            &self,
8321            snapshot: &MultiBufferSnapshot,
8322        ) -> Vec<Range<MultiBufferOffset>> {
8323            [self.start.to_offset(snapshot)..self.end.to_offset(snapshot)]
8324                .to_multi_buffer_debug_ranges(snapshot)
8325        }
8326    }
8327
8328    impl<T: ToOffset> ToMultiBufferDebugRanges for Vec<T> {
8329        fn to_multi_buffer_debug_ranges(
8330            &self,
8331            snapshot: &MultiBufferSnapshot,
8332        ) -> Vec<Range<MultiBufferOffset>> {
8333            self.as_slice().to_multi_buffer_debug_ranges(snapshot)
8334        }
8335    }
8336
8337    impl<T: ToOffset> ToMultiBufferDebugRanges for Vec<Range<T>> {
8338        fn to_multi_buffer_debug_ranges(
8339            &self,
8340            snapshot: &MultiBufferSnapshot,
8341        ) -> Vec<Range<MultiBufferOffset>> {
8342            self.as_slice().to_multi_buffer_debug_ranges(snapshot)
8343        }
8344    }
8345
8346    impl<T: ToOffset> ToMultiBufferDebugRanges for [T] {
8347        fn to_multi_buffer_debug_ranges(
8348            &self,
8349            snapshot: &MultiBufferSnapshot,
8350        ) -> Vec<Range<MultiBufferOffset>> {
8351            self.iter()
8352                .map(|item| {
8353                    let offset = item.to_offset(snapshot);
8354                    offset..offset
8355                })
8356                .collect()
8357        }
8358    }
8359
8360    impl<T: ToOffset> ToMultiBufferDebugRanges for [Range<T>] {
8361        fn to_multi_buffer_debug_ranges(
8362            &self,
8363            snapshot: &MultiBufferSnapshot,
8364        ) -> Vec<Range<MultiBufferOffset>> {
8365            self.iter()
8366                .map(|range| range.start.to_offset(snapshot)..range.end.to_offset(snapshot))
8367                .collect()
8368        }
8369    }
8370}