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