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