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