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