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