multi_buffer.rs

   1mod anchor;
   2#[cfg(test)]
   3mod multi_buffer_tests;
   4mod path_key;
   5mod transaction;
   6
   7use self::transaction::History;
   8
   9pub use anchor::{Anchor, AnchorRangeExt};
  10
  11use anyhow::{Result, anyhow};
  12use buffer_diff::{
  13    BufferDiff, BufferDiffEvent, BufferDiffSnapshot, DiffHunk, DiffHunkSecondaryStatus,
  14    DiffHunkStatus, DiffHunkStatusKind,
  15};
  16use clock::ReplicaId;
  17use collections::{BTreeMap, Bound, HashMap, HashSet};
  18use gpui::{App, Context, Entity, EntityId, EventEmitter, WeakEntity};
  19use itertools::Itertools;
  20use language::{
  21    AutoindentMode, BracketMatch, Buffer, BufferChunks, BufferRow, BufferSnapshot, Capability,
  22    CharClassifier, CharKind, CharScopeContext, Chunk, CursorShape, DiagnosticEntryRef, File,
  23    IndentGuideSettings, IndentSize, Language, LanguageScope, OffsetRangeExt, OffsetUtf16, Outline,
  24    OutlineItem, Point, PointUtf16, Selection, TextDimension, TextObject, ToOffset as _,
  25    ToPoint as _, TransactionId, TreeSitterOptions, Unclipped,
  26    language_settings::{LanguageSettings, language_settings},
  27};
  28
  29#[cfg(any(test, feature = "test-support"))]
  30use gpui::AppContext as _;
  31
  32use rope::DimensionPair;
  33use smallvec::SmallVec;
  34use smol::future::yield_now;
  35use std::{
  36    any::type_name,
  37    borrow::Cow,
  38    cell::{Cell, Ref, RefCell},
  39    cmp, fmt,
  40    future::Future,
  41    io,
  42    iter::{self, FromIterator},
  43    mem,
  44    ops::{self, AddAssign, ControlFlow, Range, RangeBounds, Sub, SubAssign},
  45    rc::Rc,
  46    str,
  47    sync::Arc,
  48    time::Duration,
  49};
  50use sum_tree::{Bias, Cursor, Dimension, Dimensions, SumTree, TreeMap};
  51use text::{
  52    BufferId, Edit, LineIndent, TextSummary,
  53    locator::Locator,
  54    subscription::{Subscription, Topic},
  55};
  56use theme::SyntaxTheme;
  57use util::post_inc;
  58use ztracing::instrument;
  59
  60pub use self::path_key::PathKey;
  61
  62#[derive(Debug, Default, Clone, Copy, Hash, PartialEq, Eq, PartialOrd, Ord)]
  63pub struct ExcerptId(u32);
  64
  65/// One or more [`Buffers`](Buffer) being edited in a single view.
  66///
  67/// See <https://zed.dev/features#multi-buffers>
  68pub struct MultiBuffer {
  69    /// A snapshot of the [`Excerpt`]s in the MultiBuffer.
  70    /// Use [`MultiBuffer::snapshot`] to get a up-to-date snapshot.
  71    snapshot: RefCell<MultiBufferSnapshot>,
  72    /// Contains the state of the buffers being edited
  73    buffers: HashMap<BufferId, BufferState>,
  74    /// Mapping from path keys to their excerpts.
  75    excerpts_by_path: BTreeMap<PathKey, Vec<ExcerptId>>,
  76    /// Mapping from excerpt IDs to their path key.
  77    paths_by_excerpt: HashMap<ExcerptId, PathKey>,
  78    /// Mapping from buffer IDs to their diff states
  79    diffs: HashMap<BufferId, DiffState>,
  80    subscriptions: Topic<MultiBufferOffset>,
  81    /// If true, the multi-buffer only contains a single [`Buffer`] and a single [`Excerpt`]
  82    singleton: bool,
  83    /// The history of the multi-buffer.
  84    history: History,
  85    /// The explicit title of the multi-buffer.
  86    /// If `None`, it will be derived from the underlying path or content.
  87    title: Option<String>,
  88    /// The writing capability of the multi-buffer.
  89    capability: Capability,
  90    buffer_changed_since_sync: Rc<Cell<bool>>,
  91}
  92
  93#[derive(Clone, Debug, PartialEq, Eq)]
  94pub enum Event {
  95    ExcerptsAdded {
  96        buffer: Entity<Buffer>,
  97        predecessor: ExcerptId,
  98        excerpts: Vec<(ExcerptId, ExcerptRange<language::Anchor>)>,
  99    },
 100    ExcerptsRemoved {
 101        ids: Vec<ExcerptId>,
 102        removed_buffer_ids: Vec<BufferId>,
 103    },
 104    ExcerptsExpanded {
 105        ids: Vec<ExcerptId>,
 106    },
 107    ExcerptsEdited {
 108        excerpt_ids: Vec<ExcerptId>,
 109        buffer_ids: Vec<BufferId>,
 110    },
 111    DiffHunksToggled,
 112    Edited {
 113        edited_buffer: Option<Entity<Buffer>>,
 114    },
 115    TransactionUndone {
 116        transaction_id: TransactionId,
 117    },
 118    Reloaded,
 119    LanguageChanged(BufferId, bool),
 120    Reparsed(BufferId),
 121    Saved,
 122    FileHandleChanged,
 123    DirtyChanged,
 124    DiagnosticsUpdated,
 125    BufferDiffChanged,
 126}
 127
 128/// A diff hunk, representing a range of consequent lines in a multibuffer.
 129#[derive(Debug, Clone, PartialEq, Eq)]
 130pub struct MultiBufferDiffHunk {
 131    /// The row range in the multibuffer where this diff hunk appears.
 132    pub row_range: Range<MultiBufferRow>,
 133    /// The buffer ID that this hunk belongs to.
 134    pub buffer_id: BufferId,
 135    /// The range of the underlying buffer that this hunk corresponds to.
 136    pub buffer_range: Range<text::Anchor>,
 137    /// The excerpt that contains the diff hunk.
 138    pub excerpt_id: ExcerptId,
 139    /// The range within the buffer's diff base that this hunk corresponds to.
 140    pub diff_base_byte_range: Range<BufferOffset>,
 141    /// The status of this hunk (added/modified/deleted and secondary status).
 142    pub status: DiffHunkStatus,
 143    /// The word diffs for this hunk.
 144    pub word_diffs: Vec<Range<MultiBufferOffset>>,
 145}
 146
 147impl MultiBufferDiffHunk {
 148    pub fn status(&self) -> DiffHunkStatus {
 149        self.status
 150    }
 151
 152    pub fn is_created_file(&self) -> bool {
 153        self.diff_base_byte_range == (BufferOffset(0)..BufferOffset(0))
 154            && self.buffer_range.start.is_min()
 155            && self.buffer_range.end.is_max()
 156    }
 157
 158    pub fn multi_buffer_range(&self) -> Range<Anchor> {
 159        let start = Anchor::in_buffer(self.excerpt_id, self.buffer_range.start);
 160        let end = Anchor::in_buffer(self.excerpt_id, self.buffer_range.end);
 161        start..end
 162    }
 163}
 164
 165pub type MultiBufferPoint = Point;
 166type ExcerptOffset = ExcerptDimension<MultiBufferOffset>;
 167type ExcerptPoint = ExcerptDimension<Point>;
 168
 169#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 170#[serde(transparent)]
 171pub struct MultiBufferRow(pub u32);
 172
 173impl MultiBufferRow {
 174    pub const MIN: Self = Self(0);
 175    pub const MAX: Self = Self(u32::MAX);
 176}
 177
 178impl ops::Add<usize> for MultiBufferRow {
 179    type Output = Self;
 180
 181    fn add(self, rhs: usize) -> Self::Output {
 182        MultiBufferRow(self.0 + rhs as u32)
 183    }
 184}
 185
 186pub trait MultiBufferDimension: 'static + Copy + Default + std::fmt::Debug {
 187    type TextDimension: TextDimension;
 188    fn from_summary(summary: &MBTextSummary) -> Self;
 189
 190    fn add_text_dim(&mut self, summary: &Self::TextDimension);
 191
 192    fn add_mb_text_summary(&mut self, summary: &MBTextSummary);
 193}
 194
 195// todo(lw): MultiBufferPoint
 196impl MultiBufferDimension for Point {
 197    type TextDimension = Point;
 198    fn from_summary(summary: &MBTextSummary) -> Self {
 199        summary.lines
 200    }
 201
 202    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 203        *self += *other;
 204    }
 205
 206    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 207        *self += summary.lines;
 208    }
 209}
 210
 211// todo(lw): MultiBufferPointUtf16
 212impl MultiBufferDimension for PointUtf16 {
 213    type TextDimension = PointUtf16;
 214    fn from_summary(summary: &MBTextSummary) -> Self {
 215        summary.lines_utf16()
 216    }
 217
 218    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 219        *self += *other;
 220    }
 221
 222    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 223        *self += summary.lines_utf16();
 224    }
 225}
 226
 227#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 228pub struct MultiBufferOffset(pub usize);
 229
 230impl fmt::Display for MultiBufferOffset {
 231    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 232        write!(f, "{}", self.0)
 233    }
 234}
 235
 236impl rand::distr::uniform::SampleUniform for MultiBufferOffset {
 237    type Sampler = MultiBufferOffsetUniformSampler;
 238}
 239
 240pub struct MultiBufferOffsetUniformSampler {
 241    sampler: rand::distr::uniform::UniformUsize,
 242}
 243
 244impl rand::distr::uniform::UniformSampler for MultiBufferOffsetUniformSampler {
 245    type X = MultiBufferOffset;
 246
 247    fn new<B1, B2>(low_b: B1, high_b: B2) -> Result<Self, rand::distr::uniform::Error>
 248    where
 249        B1: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 250        B2: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 251    {
 252        let low = *low_b.borrow();
 253        let high = *high_b.borrow();
 254        let sampler = rand::distr::uniform::UniformUsize::new(low.0, high.0);
 255        sampler.map(|sampler| MultiBufferOffsetUniformSampler { sampler })
 256    }
 257
 258    #[inline] // if the range is constant, this helps LLVM to do the
 259    // calculations at compile-time.
 260    fn new_inclusive<B1, B2>(low_b: B1, high_b: B2) -> Result<Self, rand::distr::uniform::Error>
 261    where
 262        B1: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 263        B2: rand::distr::uniform::SampleBorrow<Self::X> + Sized,
 264    {
 265        let low = *low_b.borrow();
 266        let high = *high_b.borrow();
 267        let sampler = rand::distr::uniform::UniformUsize::new_inclusive(low.0, high.0);
 268        sampler.map(|sampler| MultiBufferOffsetUniformSampler { sampler })
 269    }
 270
 271    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> Self::X {
 272        MultiBufferOffset(self.sampler.sample(rng))
 273    }
 274}
 275impl MultiBufferDimension for MultiBufferOffset {
 276    type TextDimension = usize;
 277    fn from_summary(summary: &MBTextSummary) -> Self {
 278        summary.len
 279    }
 280
 281    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 282        self.0 += *other;
 283    }
 284
 285    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 286        *self += summary.len;
 287    }
 288}
 289impl MultiBufferDimension for MultiBufferOffsetUtf16 {
 290    type TextDimension = OffsetUtf16;
 291    fn from_summary(summary: &MBTextSummary) -> Self {
 292        MultiBufferOffsetUtf16(summary.len_utf16)
 293    }
 294
 295    fn add_text_dim(&mut self, other: &Self::TextDimension) {
 296        self.0 += *other;
 297    }
 298
 299    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 300        self.0 += summary.len_utf16;
 301    }
 302}
 303
 304#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq, Hash, serde::Deserialize)]
 305pub struct BufferOffset(pub usize);
 306
 307impl TextDimension for BufferOffset {
 308    fn from_text_summary(summary: &TextSummary) -> Self {
 309        BufferOffset(usize::from_text_summary(summary))
 310    }
 311    fn from_chunk(chunk: rope::ChunkSlice) -> Self {
 312        BufferOffset(usize::from_chunk(chunk))
 313    }
 314    fn add_assign(&mut self, other: &Self) {
 315        TextDimension::add_assign(&mut self.0, &other.0);
 316    }
 317}
 318impl<'a> sum_tree::Dimension<'a, rope::ChunkSummary> for BufferOffset {
 319    fn zero(cx: ()) -> Self {
 320        BufferOffset(<usize as sum_tree::Dimension<'a, rope::ChunkSummary>>::zero(cx))
 321    }
 322
 323    fn add_summary(&mut self, summary: &'a rope::ChunkSummary, cx: ()) {
 324        usize::add_summary(&mut self.0, summary, cx);
 325    }
 326}
 327
 328impl Sub for BufferOffset {
 329    type Output = usize;
 330
 331    fn sub(self, other: BufferOffset) -> Self::Output {
 332        self.0 - other.0
 333    }
 334}
 335
 336impl AddAssign<DimensionPair<usize, Point>> for BufferOffset {
 337    fn add_assign(&mut self, other: DimensionPair<usize, Point>) {
 338        self.0 += other.key;
 339    }
 340}
 341
 342impl language::ToPoint for BufferOffset {
 343    fn to_point(&self, snapshot: &text::BufferSnapshot) -> Point {
 344        self.0.to_point(snapshot)
 345    }
 346}
 347
 348impl language::ToPointUtf16 for BufferOffset {
 349    fn to_point_utf16(&self, snapshot: &text::BufferSnapshot) -> PointUtf16 {
 350        self.0.to_point_utf16(snapshot)
 351    }
 352}
 353
 354impl language::ToOffset for BufferOffset {
 355    fn to_offset(&self, snapshot: &text::BufferSnapshot) -> usize {
 356        self.0.to_offset(snapshot)
 357    }
 358}
 359
 360impl language::ToOffsetUtf16 for BufferOffset {
 361    fn to_offset_utf16(&self, snapshot: &text::BufferSnapshot) -> OffsetUtf16 {
 362        self.0.to_offset_utf16(snapshot)
 363    }
 364}
 365
 366#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
 367pub struct MultiBufferOffsetUtf16(pub OffsetUtf16);
 368
 369impl ops::Add<usize> for MultiBufferOffsetUtf16 {
 370    type Output = MultiBufferOffsetUtf16;
 371
 372    fn add(self, rhs: usize) -> Self::Output {
 373        MultiBufferOffsetUtf16(OffsetUtf16(self.0.0 + rhs))
 374    }
 375}
 376
 377impl AddAssign<OffsetUtf16> for MultiBufferOffsetUtf16 {
 378    fn add_assign(&mut self, rhs: OffsetUtf16) {
 379        self.0 += rhs;
 380    }
 381}
 382
 383impl AddAssign<usize> for MultiBufferOffsetUtf16 {
 384    fn add_assign(&mut self, rhs: usize) {
 385        self.0.0 += rhs;
 386    }
 387}
 388
 389impl Sub for MultiBufferOffsetUtf16 {
 390    type Output = OffsetUtf16;
 391
 392    fn sub(self, other: MultiBufferOffsetUtf16) -> Self::Output {
 393        self.0 - other.0
 394    }
 395}
 396
 397#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
 398pub struct BufferOffsetUtf16(pub OffsetUtf16);
 399
 400impl MultiBufferOffset {
 401    const ZERO: Self = Self(0);
 402    pub fn saturating_sub(self, other: MultiBufferOffset) -> usize {
 403        self.0.saturating_sub(other.0)
 404    }
 405    pub fn saturating_sub_usize(self, other: usize) -> MultiBufferOffset {
 406        MultiBufferOffset(self.0.saturating_sub(other))
 407    }
 408}
 409
 410impl ops::Sub for MultiBufferOffset {
 411    type Output = usize;
 412
 413    fn sub(self, other: MultiBufferOffset) -> Self::Output {
 414        self.0 - other.0
 415    }
 416}
 417
 418impl ops::Sub<usize> for MultiBufferOffset {
 419    type Output = Self;
 420
 421    fn sub(self, other: usize) -> Self::Output {
 422        MultiBufferOffset(self.0 - other)
 423    }
 424}
 425
 426impl ops::SubAssign<usize> for MultiBufferOffset {
 427    fn sub_assign(&mut self, other: usize) {
 428        self.0 -= other;
 429    }
 430}
 431
 432impl ops::Add<usize> for BufferOffset {
 433    type Output = Self;
 434
 435    fn add(self, rhs: usize) -> Self::Output {
 436        BufferOffset(self.0 + rhs)
 437    }
 438}
 439
 440impl ops::AddAssign<usize> for BufferOffset {
 441    fn add_assign(&mut self, other: usize) {
 442        self.0 += other;
 443    }
 444}
 445
 446impl ops::Add<usize> for MultiBufferOffset {
 447    type Output = Self;
 448
 449    fn add(self, rhs: usize) -> Self::Output {
 450        MultiBufferOffset(self.0 + rhs)
 451    }
 452}
 453
 454impl ops::AddAssign<usize> for MultiBufferOffset {
 455    fn add_assign(&mut self, other: usize) {
 456        self.0 += other;
 457    }
 458}
 459
 460impl ops::Add<isize> for MultiBufferOffset {
 461    type Output = Self;
 462
 463    fn add(self, rhs: isize) -> Self::Output {
 464        MultiBufferOffset((self.0 as isize + rhs) as usize)
 465    }
 466}
 467
 468impl ops::Add for MultiBufferOffset {
 469    type Output = Self;
 470
 471    fn add(self, rhs: MultiBufferOffset) -> Self::Output {
 472        MultiBufferOffset(self.0 + rhs.0)
 473    }
 474}
 475
 476impl ops::AddAssign<MultiBufferOffset> for MultiBufferOffset {
 477    fn add_assign(&mut self, other: MultiBufferOffset) {
 478        self.0 += other.0;
 479    }
 480}
 481
 482pub trait ToOffset: 'static + fmt::Debug {
 483    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset;
 484    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16;
 485}
 486
 487pub trait ToPoint: 'static + fmt::Debug {
 488    fn to_point(&self, snapshot: &MultiBufferSnapshot) -> Point;
 489    fn to_point_utf16(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16;
 490}
 491
 492struct BufferState {
 493    buffer: Entity<Buffer>,
 494    last_version: RefCell<clock::Global>,
 495    last_non_text_state_update_count: Cell<usize>,
 496    excerpts: Vec<Locator>,
 497    _subscriptions: [gpui::Subscription; 2],
 498}
 499
 500struct DiffState {
 501    diff: Entity<BufferDiff>,
 502    /// If set, this diff is "inverted" (i.e. showing additions as deletions).
 503    /// This is used in the side-by-side diff view. The main_buffer is the
 504    /// editable buffer, while the excerpt shows the base text.
 505    main_buffer: Option<WeakEntity<Buffer>>,
 506    _subscription: gpui::Subscription,
 507}
 508
 509impl DiffState {
 510    fn snapshot(&self, cx: &App) -> DiffStateSnapshot {
 511        DiffStateSnapshot {
 512            diff: self.diff.read(cx).snapshot(cx),
 513            main_buffer: self.main_buffer.as_ref().and_then(|main_buffer| {
 514                main_buffer
 515                    .read_with(cx, |main_buffer, _| main_buffer.text_snapshot())
 516                    .ok()
 517            }),
 518        }
 519    }
 520}
 521
 522#[derive(Clone)]
 523struct DiffStateSnapshot {
 524    diff: BufferDiffSnapshot,
 525    main_buffer: Option<text::BufferSnapshot>,
 526}
 527
 528impl std::ops::Deref for DiffStateSnapshot {
 529    type Target = BufferDiffSnapshot;
 530
 531    fn deref(&self) -> &Self::Target {
 532        &self.diff
 533    }
 534}
 535
 536impl DiffState {
 537    fn new(diff: Entity<BufferDiff>, cx: &mut Context<MultiBuffer>) -> Self {
 538        DiffState {
 539            _subscription: cx.subscribe(&diff, |this, diff, event, cx| match event {
 540                BufferDiffEvent::DiffChanged {
 541                    changed_range,
 542                    base_text_changed_range: _,
 543                } => {
 544                    if let Some(changed_range) = changed_range.clone() {
 545                        this.buffer_diff_changed(diff, changed_range, cx)
 546                    }
 547                    cx.emit(Event::BufferDiffChanged);
 548                }
 549                BufferDiffEvent::LanguageChanged => this.buffer_diff_language_changed(diff, cx),
 550                _ => {}
 551            }),
 552            diff,
 553            main_buffer: None,
 554        }
 555    }
 556
 557    fn new_inverted(
 558        diff: Entity<BufferDiff>,
 559        main_buffer: Entity<Buffer>,
 560        cx: &mut Context<MultiBuffer>,
 561    ) -> Self {
 562        let main_buffer = main_buffer.downgrade();
 563        DiffState {
 564            _subscription: cx.subscribe(&diff, {
 565                let main_buffer = main_buffer.clone();
 566                move |this, diff, event, cx| match event {
 567                    BufferDiffEvent::DiffChanged {
 568                        changed_range: _,
 569                        base_text_changed_range,
 570                    } => {
 571                        if let Some(base_text_changed_range) = base_text_changed_range.clone() {
 572                            this.inverted_buffer_diff_changed(
 573                                diff,
 574                                base_text_changed_range,
 575                                main_buffer.clone(),
 576                                cx,
 577                            )
 578                        }
 579                        cx.emit(Event::BufferDiffChanged);
 580                    }
 581                    BufferDiffEvent::LanguageChanged => {
 582                        this.inverted_buffer_diff_language_changed(diff, main_buffer.clone(), cx)
 583                    }
 584                    _ => {}
 585                }
 586            }),
 587            diff,
 588            main_buffer: Some(main_buffer),
 589        }
 590    }
 591}
 592
 593/// The contents of a [`MultiBuffer`] at a single point in time.
 594#[derive(Clone, Default)]
 595pub struct MultiBufferSnapshot {
 596    excerpts: SumTree<Excerpt>,
 597    diffs: TreeMap<BufferId, DiffStateSnapshot>,
 598    diff_transforms: SumTree<DiffTransform>,
 599    non_text_state_update_count: usize,
 600    edit_count: usize,
 601    is_dirty: bool,
 602    has_deleted_file: bool,
 603    has_conflict: bool,
 604    has_inverted_diff: bool,
 605    /// immutable fields
 606    singleton: bool,
 607    excerpt_ids: SumTree<ExcerptIdMapping>,
 608    replaced_excerpts: TreeMap<ExcerptId, ExcerptId>,
 609    trailing_excerpt_update_count: usize,
 610    all_diff_hunks_expanded: bool,
 611    show_deleted_hunks: bool,
 612    show_headers: bool,
 613}
 614
 615// follower: None
 616// - BufferContent(Some)
 617// - BufferContent(None)
 618// - DeletedHunk
 619//
 620// follower: Some
 621// - BufferContent(Some)
 622// - BufferContent(None)
 623
 624#[derive(Debug, Clone)]
 625enum DiffTransform {
 626    // RealText
 627    BufferContent {
 628        summary: MBTextSummary,
 629        // modified_hunk_info
 630        inserted_hunk_info: Option<DiffTransformHunkInfo>,
 631    },
 632    // ExpandedHunkText
 633    DeletedHunk {
 634        summary: TextSummary,
 635        buffer_id: BufferId,
 636        hunk_info: DiffTransformHunkInfo,
 637        base_text_byte_range: Range<usize>,
 638        has_trailing_newline: bool,
 639    },
 640}
 641
 642#[derive(Clone, Copy, Debug)]
 643struct DiffTransformHunkInfo {
 644    excerpt_id: ExcerptId,
 645    hunk_start_anchor: text::Anchor,
 646    hunk_secondary_status: DiffHunkSecondaryStatus,
 647    is_logically_deleted: bool,
 648}
 649
 650impl Eq for DiffTransformHunkInfo {}
 651
 652impl PartialEq for DiffTransformHunkInfo {
 653    fn eq(&self, other: &DiffTransformHunkInfo) -> bool {
 654        self.excerpt_id == other.excerpt_id && self.hunk_start_anchor == other.hunk_start_anchor
 655    }
 656}
 657
 658impl std::hash::Hash for DiffTransformHunkInfo {
 659    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
 660        self.excerpt_id.hash(state);
 661        self.hunk_start_anchor.hash(state);
 662    }
 663}
 664
 665#[derive(Clone)]
 666pub struct ExcerptInfo {
 667    pub id: ExcerptId,
 668    pub buffer: BufferSnapshot,
 669    pub buffer_id: BufferId,
 670    pub range: ExcerptRange<text::Anchor>,
 671    pub end_row: MultiBufferRow,
 672}
 673
 674impl std::fmt::Debug for ExcerptInfo {
 675    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 676        f.debug_struct(type_name::<Self>())
 677            .field("id", &self.id)
 678            .field("buffer_id", &self.buffer_id)
 679            .field("path", &self.buffer.file().map(|f| f.path()))
 680            .field("range", &self.range)
 681            .finish()
 682    }
 683}
 684
 685/// A boundary between `Excerpt`s in a [`MultiBuffer`]
 686#[derive(Debug)]
 687pub struct ExcerptBoundary {
 688    pub prev: Option<ExcerptInfo>,
 689    pub next: ExcerptInfo,
 690    /// The row in the `MultiBuffer` where the boundary is located
 691    pub row: MultiBufferRow,
 692}
 693
 694impl ExcerptBoundary {
 695    pub fn starts_new_buffer(&self) -> bool {
 696        match (self.prev.as_ref(), &self.next) {
 697            (None, _) => true,
 698            (Some(prev), next) => prev.buffer_id != next.buffer_id,
 699        }
 700    }
 701}
 702
 703#[derive(Copy, Clone, Debug, PartialEq, Eq)]
 704pub struct ExpandInfo {
 705    pub direction: ExpandExcerptDirection,
 706    pub excerpt_id: ExcerptId,
 707}
 708
 709#[derive(Copy, Clone, Debug, Default, PartialEq, Eq)]
 710pub struct RowInfo {
 711    pub buffer_id: Option<BufferId>,
 712    pub buffer_row: Option<u32>,
 713    pub multibuffer_row: Option<MultiBufferRow>,
 714    pub diff_status: Option<buffer_diff::DiffHunkStatus>,
 715    pub expand_info: Option<ExpandInfo>,
 716    pub wrapped_buffer_row: Option<u32>,
 717}
 718
 719/// A slice into a [`Buffer`] that is being edited in a [`MultiBuffer`].
 720#[derive(Clone)]
 721struct Excerpt {
 722    /// The unique identifier for this excerpt
 723    id: ExcerptId,
 724    /// The location of the excerpt in the [`MultiBuffer`]
 725    locator: Locator,
 726    /// The buffer being excerpted
 727    buffer_id: BufferId,
 728    /// A snapshot of the buffer being excerpted
 729    buffer: BufferSnapshot,
 730    /// The range of the buffer to be shown in the excerpt
 731    range: ExcerptRange<text::Anchor>,
 732    /// The last row in the excerpted slice of the buffer
 733    max_buffer_row: BufferRow,
 734    /// A summary of the text in the excerpt
 735    text_summary: TextSummary,
 736    has_trailing_newline: bool,
 737}
 738
 739/// A public view into an `Excerpt` in a [`MultiBuffer`].
 740///
 741/// Contains methods for getting the [`Buffer`] of the excerpt,
 742/// as well as mapping offsets to/from buffer and multibuffer coordinates.
 743#[derive(Clone)]
 744pub struct MultiBufferExcerpt<'a> {
 745    excerpt: &'a Excerpt,
 746    diff_transforms:
 747        sum_tree::Cursor<'a, 'static, DiffTransform, DiffTransforms<MultiBufferOffset>>,
 748    /// The offset in the multibuffer considering diff transforms.
 749    offset: MultiBufferOffset,
 750    /// The offset in the multibuffer without diff transforms.
 751    excerpt_offset: ExcerptOffset,
 752    buffer_offset: BufferOffset,
 753}
 754
 755#[derive(Clone, Debug)]
 756struct ExcerptIdMapping {
 757    id: ExcerptId,
 758    locator: Locator,
 759}
 760
 761/// A range of text from a single [`Buffer`], to be shown as an `Excerpt`.
 762/// These ranges are relative to the buffer itself
 763#[derive(Clone, Debug, Eq, PartialEq, Hash)]
 764pub struct ExcerptRange<T> {
 765    /// The full range of text to be shown in the excerpt.
 766    pub context: Range<T>,
 767    /// The primary range of text to be highlighted in the excerpt.
 768    /// In a multi-buffer search, this would be the text that matched the search
 769    pub primary: Range<T>,
 770}
 771
 772impl<T: Clone> ExcerptRange<T> {
 773    pub fn new(context: Range<T>) -> Self {
 774        Self {
 775            context: context.clone(),
 776            primary: context,
 777        }
 778    }
 779}
 780
 781#[derive(Clone, Debug, Default)]
 782pub struct ExcerptSummary {
 783    excerpt_id: ExcerptId,
 784    /// The location of the last [`Excerpt`] being summarized
 785    excerpt_locator: Locator,
 786    widest_line_number: u32,
 787    text: MBTextSummary,
 788}
 789
 790#[derive(Debug, Clone)]
 791pub struct DiffTransformSummary {
 792    input: MBTextSummary,
 793    output: MBTextSummary,
 794}
 795
 796/// Summary of a string of text.
 797#[derive(Copy, Clone, Debug, Default, Eq, PartialEq)]
 798pub struct MBTextSummary {
 799    /// Length in bytes.
 800    pub len: MultiBufferOffset,
 801    /// Length in UTF-8.
 802    pub chars: usize,
 803    /// Length in UTF-16 code units
 804    pub len_utf16: OffsetUtf16,
 805    /// A point representing the number of lines and the length of the last line.
 806    ///
 807    /// In other words, it marks the point after the last byte in the text, (if
 808    /// EOF was a character, this would be its position).
 809    pub lines: Point,
 810    /// How many `char`s are in the first line
 811    pub first_line_chars: u32,
 812    /// How many `char`s are in the last line
 813    pub last_line_chars: u32,
 814    /// How many UTF-16 code units are in the last line
 815    pub last_line_len_utf16: u32,
 816    /// The row idx of the longest row
 817    pub longest_row: u32,
 818    /// How many `char`s are in the longest row
 819    pub longest_row_chars: u32,
 820}
 821
 822impl From<TextSummary> for MBTextSummary {
 823    fn from(summary: TextSummary) -> Self {
 824        MBTextSummary {
 825            len: MultiBufferOffset(summary.len),
 826            chars: summary.chars,
 827            len_utf16: summary.len_utf16,
 828            lines: summary.lines,
 829            first_line_chars: summary.first_line_chars,
 830            last_line_chars: summary.last_line_chars,
 831            last_line_len_utf16: summary.last_line_len_utf16,
 832            longest_row: summary.longest_row,
 833            longest_row_chars: summary.longest_row_chars,
 834        }
 835    }
 836}
 837impl From<&str> for MBTextSummary {
 838    fn from(text: &str) -> Self {
 839        MBTextSummary::from(TextSummary::from(text))
 840    }
 841}
 842
 843impl MultiBufferDimension for MBTextSummary {
 844    type TextDimension = TextSummary;
 845
 846    fn from_summary(summary: &MBTextSummary) -> Self {
 847        *summary
 848    }
 849
 850    fn add_text_dim(&mut self, summary: &Self::TextDimension) {
 851        *self += *summary;
 852    }
 853
 854    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 855        *self += *summary;
 856    }
 857}
 858
 859impl AddAssign for MBTextSummary {
 860    fn add_assign(&mut self, other: MBTextSummary) {
 861        let joined_chars = self.last_line_chars + other.first_line_chars;
 862        if joined_chars > self.longest_row_chars {
 863            self.longest_row = self.lines.row;
 864            self.longest_row_chars = joined_chars;
 865        }
 866        if other.longest_row_chars > self.longest_row_chars {
 867            self.longest_row = self.lines.row + other.longest_row;
 868            self.longest_row_chars = other.longest_row_chars;
 869        }
 870
 871        if self.lines.row == 0 {
 872            self.first_line_chars += other.first_line_chars;
 873        }
 874
 875        if other.lines.row == 0 {
 876            self.last_line_chars += other.first_line_chars;
 877            self.last_line_len_utf16 += other.last_line_len_utf16;
 878        } else {
 879            self.last_line_chars = other.last_line_chars;
 880            self.last_line_len_utf16 = other.last_line_len_utf16;
 881        }
 882
 883        self.chars += other.chars;
 884        self.len += other.len;
 885        self.len_utf16 += other.len_utf16;
 886        self.lines += other.lines;
 887    }
 888}
 889
 890impl AddAssign<TextSummary> for MBTextSummary {
 891    fn add_assign(&mut self, other: TextSummary) {
 892        *self += MBTextSummary::from(other);
 893    }
 894}
 895
 896impl MBTextSummary {
 897    pub fn lines_utf16(&self) -> PointUtf16 {
 898        PointUtf16 {
 899            row: self.lines.row,
 900            column: self.last_line_len_utf16,
 901        }
 902    }
 903}
 904
 905impl<K, V> MultiBufferDimension for DimensionPair<K, V>
 906where
 907    K: MultiBufferDimension,
 908    V: MultiBufferDimension,
 909{
 910    type TextDimension = DimensionPair<K::TextDimension, V::TextDimension>;
 911
 912    fn from_summary(summary: &MBTextSummary) -> Self {
 913        Self {
 914            key: K::from_summary(summary),
 915            value: Some(V::from_summary(summary)),
 916        }
 917    }
 918
 919    fn add_text_dim(&mut self, summary: &Self::TextDimension) {
 920        self.key.add_text_dim(&summary.key);
 921        if let Some(value) = &mut self.value {
 922            if let Some(other_value) = summary.value.as_ref() {
 923                value.add_text_dim(other_value);
 924            }
 925        }
 926    }
 927
 928    fn add_mb_text_summary(&mut self, summary: &MBTextSummary) {
 929        self.key.add_mb_text_summary(summary);
 930        if let Some(value) = &mut self.value {
 931            value.add_mb_text_summary(summary);
 932        }
 933    }
 934}
 935
 936#[derive(Clone)]
 937pub struct MultiBufferRows<'a> {
 938    point: Point,
 939    is_empty: bool,
 940    is_singleton: bool,
 941    cursor: MultiBufferCursor<'a, Point, Point>,
 942}
 943
 944pub struct MultiBufferChunks<'a> {
 945    excerpts: Cursor<'a, 'static, Excerpt, ExcerptOffset>,
 946    diff_transforms:
 947        Cursor<'a, 'static, DiffTransform, Dimensions<MultiBufferOffset, ExcerptOffset>>,
 948    diffs: &'a TreeMap<BufferId, DiffStateSnapshot>,
 949    diff_base_chunks: Option<(BufferId, BufferChunks<'a>)>,
 950    buffer_chunk: Option<Chunk<'a>>,
 951    range: Range<MultiBufferOffset>,
 952    excerpt_offset_range: Range<ExcerptOffset>,
 953    excerpt_chunks: Option<ExcerptChunks<'a>>,
 954    language_aware: bool,
 955}
 956
 957pub struct ReversedMultiBufferChunks<'a> {
 958    cursor: MultiBufferCursor<'a, MultiBufferOffset, BufferOffset>,
 959    current_chunks: Option<rope::Chunks<'a>>,
 960    start: MultiBufferOffset,
 961    offset: MultiBufferOffset,
 962}
 963
 964pub struct MultiBufferBytes<'a> {
 965    range: Range<MultiBufferOffset>,
 966    cursor: MultiBufferCursor<'a, MultiBufferOffset, BufferOffset>,
 967    excerpt_bytes: Option<text::Bytes<'a>>,
 968    has_trailing_newline: bool,
 969    chunk: &'a [u8],
 970}
 971
 972pub struct ReversedMultiBufferBytes<'a> {
 973    range: Range<MultiBufferOffset>,
 974    chunks: ReversedMultiBufferChunks<'a>,
 975    chunk: &'a [u8],
 976}
 977
 978#[derive(Clone)]
 979struct DiffTransforms<MBD> {
 980    output_dimension: OutputDimension<MBD>,
 981    excerpt_dimension: ExcerptDimension<MBD>,
 982}
 983
 984impl<'a, MBD: MultiBufferDimension> Dimension<'a, DiffTransformSummary> for DiffTransforms<MBD> {
 985    fn zero(cx: <DiffTransformSummary as sum_tree::Summary>::Context<'_>) -> Self {
 986        Self {
 987            output_dimension: OutputDimension::zero(cx),
 988            excerpt_dimension: <ExcerptDimension<MBD> as Dimension<'a, DiffTransformSummary>>::zero(
 989                cx,
 990            ),
 991        }
 992    }
 993
 994    fn add_summary(
 995        &mut self,
 996        summary: &'a DiffTransformSummary,
 997        cx: <DiffTransformSummary as sum_tree::Summary>::Context<'_>,
 998    ) {
 999        self.output_dimension.add_summary(summary, cx);
1000        self.excerpt_dimension.add_summary(summary, cx);
1001    }
1002}
1003
1004#[derive(Clone)]
1005struct MultiBufferCursor<'a, MBD, BD> {
1006    excerpts: Cursor<'a, 'static, Excerpt, ExcerptDimension<MBD>>,
1007    diff_transforms: Cursor<'a, 'static, DiffTransform, DiffTransforms<MBD>>,
1008    diffs: &'a TreeMap<BufferId, DiffStateSnapshot>,
1009    cached_region: Option<MultiBufferRegion<'a, MBD, BD>>,
1010}
1011
1012#[derive(Clone)]
1013struct MultiBufferRegion<'a, MBD, BD> {
1014    buffer: &'a BufferSnapshot,
1015    is_main_buffer: bool,
1016    diff_hunk_status: Option<DiffHunkStatus>,
1017    excerpt: &'a Excerpt,
1018    buffer_range: Range<BD>,
1019    range: Range<MBD>,
1020    has_trailing_newline: bool,
1021}
1022
1023struct ExcerptChunks<'a> {
1024    excerpt_id: ExcerptId,
1025    content_chunks: BufferChunks<'a>,
1026    has_footer: bool,
1027}
1028
1029#[derive(Debug)]
1030struct BufferEdit {
1031    range: Range<BufferOffset>,
1032    new_text: Arc<str>,
1033    is_insertion: bool,
1034    original_indent_column: Option<u32>,
1035    excerpt_id: ExcerptId,
1036}
1037
1038#[derive(Clone, Copy, Debug, PartialEq)]
1039enum DiffChangeKind {
1040    BufferEdited,
1041    DiffUpdated { base_changed: bool },
1042    ExpandOrCollapseHunks { expand: bool },
1043}
1044
1045#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
1046pub enum ExpandExcerptDirection {
1047    Up,
1048    Down,
1049    UpAndDown,
1050}
1051
1052impl ExpandExcerptDirection {
1053    pub fn should_expand_up(&self) -> bool {
1054        match self {
1055            ExpandExcerptDirection::Up => true,
1056            ExpandExcerptDirection::Down => false,
1057            ExpandExcerptDirection::UpAndDown => true,
1058        }
1059    }
1060
1061    pub fn should_expand_down(&self) -> bool {
1062        match self {
1063            ExpandExcerptDirection::Up => false,
1064            ExpandExcerptDirection::Down => true,
1065            ExpandExcerptDirection::UpAndDown => true,
1066        }
1067    }
1068}
1069
1070#[derive(Clone, Debug, PartialEq)]
1071pub struct IndentGuide {
1072    pub buffer_id: BufferId,
1073    pub start_row: MultiBufferRow,
1074    pub end_row: MultiBufferRow,
1075    pub depth: u32,
1076    pub tab_size: u32,
1077    pub settings: IndentGuideSettings,
1078}
1079
1080impl IndentGuide {
1081    pub fn indent_level(&self) -> u32 {
1082        self.depth * self.tab_size
1083    }
1084}
1085
1086impl MultiBuffer {
1087    pub fn new(capability: Capability) -> Self {
1088        Self::new_(
1089            capability,
1090            MultiBufferSnapshot {
1091                show_headers: true,
1092                show_deleted_hunks: true,
1093                ..MultiBufferSnapshot::default()
1094            },
1095        )
1096    }
1097
1098    pub fn without_headers(capability: Capability) -> Self {
1099        Self::new_(
1100            capability,
1101            MultiBufferSnapshot {
1102                show_deleted_hunks: true,
1103                ..MultiBufferSnapshot::default()
1104            },
1105        )
1106    }
1107
1108    pub fn singleton(buffer: Entity<Buffer>, cx: &mut Context<Self>) -> Self {
1109        let mut this = Self::new_(
1110            buffer.read(cx).capability(),
1111            MultiBufferSnapshot {
1112                singleton: true,
1113                show_deleted_hunks: true,
1114                ..MultiBufferSnapshot::default()
1115            },
1116        );
1117        this.singleton = true;
1118        let buffer_id = buffer.read(cx).remote_id();
1119        this.push_excerpts(
1120            buffer,
1121            [ExcerptRange::new(text::Anchor::min_max_range_for_buffer(
1122                buffer_id,
1123            ))],
1124            cx,
1125        );
1126        this
1127    }
1128
1129    #[inline]
1130    pub fn new_(capability: Capability, snapshot: MultiBufferSnapshot) -> Self {
1131        Self {
1132            snapshot: RefCell::new(snapshot),
1133            buffers: Default::default(),
1134            diffs: HashMap::default(),
1135            subscriptions: Topic::default(),
1136            singleton: false,
1137            capability,
1138            title: None,
1139            excerpts_by_path: Default::default(),
1140            paths_by_excerpt: Default::default(),
1141            buffer_changed_since_sync: Default::default(),
1142            history: History::default(),
1143        }
1144    }
1145
1146    pub fn clone(&self, new_cx: &mut Context<Self>) -> Self {
1147        let mut buffers = HashMap::default();
1148        let buffer_changed_since_sync = Rc::new(Cell::new(false));
1149        for (buffer_id, buffer_state) in self.buffers.iter() {
1150            buffer_state.buffer.update(new_cx, |buffer, _| {
1151                buffer.record_changes(Rc::downgrade(&buffer_changed_since_sync));
1152            });
1153            buffers.insert(
1154                *buffer_id,
1155                BufferState {
1156                    buffer: buffer_state.buffer.clone(),
1157                    last_version: buffer_state.last_version.clone(),
1158                    last_non_text_state_update_count: buffer_state
1159                        .last_non_text_state_update_count
1160                        .clone(),
1161                    excerpts: buffer_state.excerpts.clone(),
1162                    _subscriptions: [
1163                        new_cx.observe(&buffer_state.buffer, |_, _, cx| cx.notify()),
1164                        new_cx.subscribe(&buffer_state.buffer, Self::on_buffer_event),
1165                    ],
1166                },
1167            );
1168        }
1169        let mut diff_bases = HashMap::default();
1170        for (buffer_id, diff) in self.diffs.iter() {
1171            diff_bases.insert(*buffer_id, DiffState::new(diff.diff.clone(), new_cx));
1172        }
1173        Self {
1174            snapshot: RefCell::new(self.snapshot.borrow().clone()),
1175            buffers: buffers,
1176            excerpts_by_path: Default::default(),
1177            paths_by_excerpt: Default::default(),
1178            diffs: diff_bases,
1179            subscriptions: Default::default(),
1180            singleton: self.singleton,
1181            capability: self.capability,
1182            history: self.history.clone(),
1183            title: self.title.clone(),
1184            buffer_changed_since_sync,
1185        }
1186    }
1187
1188    pub fn set_group_interval(&mut self, group_interval: Duration) {
1189        self.history.set_group_interval(group_interval);
1190    }
1191
1192    pub fn with_title(mut self, title: String) -> Self {
1193        self.title = Some(title);
1194        self
1195    }
1196
1197    pub fn read_only(&self) -> bool {
1198        !self.capability.editable()
1199    }
1200
1201    /// Returns an up-to-date snapshot of the MultiBuffer.
1202    #[ztracing::instrument(skip_all)]
1203    pub fn snapshot(&self, cx: &App) -> MultiBufferSnapshot {
1204        self.sync(cx);
1205        self.snapshot.borrow().clone()
1206    }
1207
1208    pub fn read(&self, cx: &App) -> Ref<'_, MultiBufferSnapshot> {
1209        self.sync(cx);
1210        self.snapshot.borrow()
1211    }
1212
1213    pub fn as_singleton(&self) -> Option<Entity<Buffer>> {
1214        if self.singleton {
1215            Some(self.buffers.values().next().unwrap().buffer.clone())
1216        } else {
1217            None
1218        }
1219    }
1220
1221    pub fn is_singleton(&self) -> bool {
1222        self.singleton
1223    }
1224
1225    pub fn subscribe(&mut self) -> Subscription<MultiBufferOffset> {
1226        self.subscriptions.subscribe()
1227    }
1228
1229    pub fn is_dirty(&self, cx: &App) -> bool {
1230        self.read(cx).is_dirty()
1231    }
1232
1233    pub fn has_deleted_file(&self, cx: &App) -> bool {
1234        self.read(cx).has_deleted_file()
1235    }
1236
1237    pub fn has_conflict(&self, cx: &App) -> bool {
1238        self.read(cx).has_conflict()
1239    }
1240
1241    // The `is_empty` signature doesn't match what clippy expects
1242    #[allow(clippy::len_without_is_empty)]
1243    pub fn len(&self, cx: &App) -> MultiBufferOffset {
1244        self.read(cx).len()
1245    }
1246
1247    pub fn is_empty(&self) -> bool {
1248        self.buffers.is_empty()
1249    }
1250
1251    pub fn edit<I, S, T>(
1252        &mut self,
1253        edits: I,
1254        autoindent_mode: Option<AutoindentMode>,
1255        cx: &mut Context<Self>,
1256    ) where
1257        I: IntoIterator<Item = (Range<S>, T)>,
1258        S: ToOffset,
1259        T: Into<Arc<str>>,
1260    {
1261        self.edit_internal(edits, autoindent_mode, true, cx);
1262    }
1263
1264    pub fn edit_non_coalesce<I, S, T>(
1265        &mut self,
1266        edits: I,
1267        autoindent_mode: Option<AutoindentMode>,
1268        cx: &mut Context<Self>,
1269    ) where
1270        I: IntoIterator<Item = (Range<S>, T)>,
1271        S: ToOffset,
1272        T: Into<Arc<str>>,
1273    {
1274        self.edit_internal(edits, autoindent_mode, false, cx);
1275    }
1276
1277    fn edit_internal<I, S, T>(
1278        &mut self,
1279        edits: I,
1280        autoindent_mode: Option<AutoindentMode>,
1281        coalesce_adjacent: bool,
1282        cx: &mut Context<Self>,
1283    ) where
1284        I: IntoIterator<Item = (Range<S>, T)>,
1285        S: ToOffset,
1286        T: Into<Arc<str>>,
1287    {
1288        if self.read_only() || self.buffers.is_empty() {
1289            return;
1290        }
1291        self.sync_mut(cx);
1292        let edits = edits
1293            .into_iter()
1294            .map(|(range, new_text)| {
1295                let mut range = range.start.to_offset(self.snapshot.get_mut())
1296                    ..range.end.to_offset(self.snapshot.get_mut());
1297                if range.start > range.end {
1298                    mem::swap(&mut range.start, &mut range.end);
1299                }
1300                (range, new_text.into())
1301            })
1302            .collect::<Vec<_>>();
1303
1304        return edit_internal(self, edits, autoindent_mode, coalesce_adjacent, cx);
1305
1306        // Non-generic part of edit, hoisted out to avoid blowing up LLVM IR.
1307        fn edit_internal(
1308            this: &mut MultiBuffer,
1309            edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1310            mut autoindent_mode: Option<AutoindentMode>,
1311            coalesce_adjacent: bool,
1312            cx: &mut Context<MultiBuffer>,
1313        ) {
1314            let original_indent_columns = match &mut autoindent_mode {
1315                Some(AutoindentMode::Block {
1316                    original_indent_columns,
1317                }) => mem::take(original_indent_columns),
1318                _ => Default::default(),
1319            };
1320
1321            let (buffer_edits, edited_excerpt_ids) = MultiBuffer::convert_edits_to_buffer_edits(
1322                edits,
1323                this.snapshot.get_mut(),
1324                &original_indent_columns,
1325            );
1326
1327            let mut buffer_ids = Vec::with_capacity(buffer_edits.len());
1328            for (buffer_id, mut edits) in buffer_edits {
1329                buffer_ids.push(buffer_id);
1330                edits.sort_by_key(|edit| edit.range.start);
1331                this.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1332                    let mut edits = edits.into_iter().peekable();
1333                    let mut insertions = Vec::new();
1334                    let mut original_indent_columns = Vec::new();
1335                    let mut deletions = Vec::new();
1336                    let empty_str: Arc<str> = Arc::default();
1337                    while let Some(BufferEdit {
1338                        mut range,
1339                        mut new_text,
1340                        mut is_insertion,
1341                        original_indent_column,
1342                        excerpt_id,
1343                    }) = edits.next()
1344                    {
1345                        while let Some(BufferEdit {
1346                            range: next_range,
1347                            is_insertion: next_is_insertion,
1348                            new_text: next_new_text,
1349                            excerpt_id: next_excerpt_id,
1350                            ..
1351                        }) = edits.peek()
1352                        {
1353                            let should_coalesce = if coalesce_adjacent {
1354                                range.end >= next_range.start
1355                            } else {
1356                                range.end > next_range.start
1357                            };
1358
1359                            if should_coalesce {
1360                                range.end = cmp::max(next_range.end, range.end);
1361                                is_insertion |= *next_is_insertion;
1362                                if excerpt_id == *next_excerpt_id {
1363                                    new_text = format!("{new_text}{next_new_text}").into();
1364                                }
1365                                edits.next();
1366                            } else {
1367                                break;
1368                            }
1369                        }
1370
1371                        if is_insertion {
1372                            original_indent_columns.push(original_indent_column);
1373                            insertions.push((
1374                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
1375                                new_text.clone(),
1376                            ));
1377                        } else if !range.is_empty() {
1378                            deletions.push((
1379                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
1380                                empty_str.clone(),
1381                            ));
1382                        }
1383                    }
1384
1385                    let deletion_autoindent_mode =
1386                        if let Some(AutoindentMode::Block { .. }) = autoindent_mode {
1387                            Some(AutoindentMode::Block {
1388                                original_indent_columns: Default::default(),
1389                            })
1390                        } else {
1391                            autoindent_mode.clone()
1392                        };
1393                    let insertion_autoindent_mode =
1394                        if let Some(AutoindentMode::Block { .. }) = autoindent_mode {
1395                            Some(AutoindentMode::Block {
1396                                original_indent_columns,
1397                            })
1398                        } else {
1399                            autoindent_mode.clone()
1400                        };
1401
1402                    if coalesce_adjacent {
1403                        buffer.edit(deletions, deletion_autoindent_mode, cx);
1404                        buffer.edit(insertions, insertion_autoindent_mode, cx);
1405                    } else {
1406                        buffer.edit_non_coalesce(deletions, deletion_autoindent_mode, cx);
1407                        buffer.edit_non_coalesce(insertions, insertion_autoindent_mode, cx);
1408                    }
1409                })
1410            }
1411
1412            cx.emit(Event::ExcerptsEdited {
1413                excerpt_ids: edited_excerpt_ids,
1414                buffer_ids,
1415            });
1416        }
1417    }
1418
1419    fn convert_edits_to_buffer_edits(
1420        edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1421        snapshot: &MultiBufferSnapshot,
1422        original_indent_columns: &[Option<u32>],
1423    ) -> (HashMap<BufferId, Vec<BufferEdit>>, Vec<ExcerptId>) {
1424        let mut buffer_edits: HashMap<BufferId, Vec<BufferEdit>> = Default::default();
1425        let mut edited_excerpt_ids = Vec::new();
1426        let mut cursor = snapshot.cursor::<MultiBufferOffset, BufferOffset>();
1427        for (ix, (range, new_text)) in edits.into_iter().enumerate() {
1428            let original_indent_column = original_indent_columns.get(ix).copied().flatten();
1429
1430            cursor.seek(&range.start);
1431            let mut start_region = cursor.region().expect("start offset out of bounds");
1432            if !start_region.is_main_buffer {
1433                cursor.next();
1434                if let Some(region) = cursor.region() {
1435                    start_region = region;
1436                } else {
1437                    continue;
1438                }
1439            }
1440
1441            if range.end < start_region.range.start {
1442                continue;
1443            }
1444
1445            if range.end > start_region.range.end {
1446                cursor.seek_forward(&range.end);
1447            }
1448            let mut end_region = cursor.region().expect("end offset out of bounds");
1449            if !end_region.is_main_buffer {
1450                cursor.prev();
1451                if let Some(region) = cursor.region() {
1452                    end_region = region;
1453                } else {
1454                    continue;
1455                }
1456            }
1457
1458            if range.start > end_region.range.end {
1459                continue;
1460            }
1461
1462            let start_overshoot = range.start.saturating_sub(start_region.range.start);
1463            let end_overshoot = range.end.saturating_sub(end_region.range.start);
1464            let buffer_start = (start_region.buffer_range.start + start_overshoot)
1465                .min(start_region.buffer_range.end);
1466            let buffer_end =
1467                (end_region.buffer_range.start + end_overshoot).min(end_region.buffer_range.end);
1468
1469            if start_region.excerpt.id == end_region.excerpt.id {
1470                if start_region.buffer.capability == Capability::ReadWrite
1471                    && start_region.is_main_buffer
1472                {
1473                    edited_excerpt_ids.push(start_region.excerpt.id);
1474                    buffer_edits
1475                        .entry(start_region.buffer.remote_id())
1476                        .or_default()
1477                        .push(BufferEdit {
1478                            range: buffer_start..buffer_end,
1479                            new_text,
1480                            is_insertion: true,
1481                            original_indent_column,
1482                            excerpt_id: start_region.excerpt.id,
1483                        });
1484                }
1485            } else {
1486                let start_excerpt_range = buffer_start..start_region.buffer_range.end;
1487                let end_excerpt_range = end_region.buffer_range.start..buffer_end;
1488                if start_region.buffer.capability == Capability::ReadWrite
1489                    && start_region.is_main_buffer
1490                {
1491                    edited_excerpt_ids.push(start_region.excerpt.id);
1492                    buffer_edits
1493                        .entry(start_region.buffer.remote_id())
1494                        .or_default()
1495                        .push(BufferEdit {
1496                            range: start_excerpt_range,
1497                            new_text: new_text.clone(),
1498                            is_insertion: true,
1499                            original_indent_column,
1500                            excerpt_id: start_region.excerpt.id,
1501                        });
1502                }
1503                if end_region.buffer.capability == Capability::ReadWrite
1504                    && end_region.is_main_buffer
1505                {
1506                    edited_excerpt_ids.push(end_region.excerpt.id);
1507                    buffer_edits
1508                        .entry(end_region.buffer.remote_id())
1509                        .or_default()
1510                        .push(BufferEdit {
1511                            range: end_excerpt_range,
1512                            new_text: new_text.clone(),
1513                            is_insertion: false,
1514                            original_indent_column,
1515                            excerpt_id: end_region.excerpt.id,
1516                        });
1517                }
1518
1519                cursor.seek(&range.start);
1520                cursor.next_excerpt();
1521                while let Some(region) = cursor.region() {
1522                    if region.excerpt.id == end_region.excerpt.id {
1523                        break;
1524                    }
1525                    if region.buffer.capability == Capability::ReadWrite && region.is_main_buffer {
1526                        edited_excerpt_ids.push(region.excerpt.id);
1527                        buffer_edits
1528                            .entry(region.buffer.remote_id())
1529                            .or_default()
1530                            .push(BufferEdit {
1531                                range: region.buffer_range,
1532                                new_text: new_text.clone(),
1533                                is_insertion: false,
1534                                original_indent_column,
1535                                excerpt_id: region.excerpt.id,
1536                            });
1537                    }
1538                    cursor.next_excerpt();
1539                }
1540            }
1541        }
1542        (buffer_edits, edited_excerpt_ids)
1543    }
1544
1545    pub fn autoindent_ranges<I, S>(&mut self, ranges: I, cx: &mut Context<Self>)
1546    where
1547        I: IntoIterator<Item = Range<S>>,
1548        S: ToOffset,
1549    {
1550        if self.read_only() || self.buffers.is_empty() {
1551            return;
1552        }
1553        self.sync_mut(cx);
1554        let empty = Arc::<str>::from("");
1555        let edits = ranges
1556            .into_iter()
1557            .map(|range| {
1558                let mut range = range.start.to_offset(self.snapshot.get_mut())
1559                    ..range.end.to_offset(&self.snapshot.get_mut());
1560                if range.start > range.end {
1561                    mem::swap(&mut range.start, &mut range.end);
1562                }
1563                (range, empty.clone())
1564            })
1565            .collect::<Vec<_>>();
1566
1567        return autoindent_ranges_internal(self, edits, cx);
1568
1569        fn autoindent_ranges_internal(
1570            this: &mut MultiBuffer,
1571            edits: Vec<(Range<MultiBufferOffset>, Arc<str>)>,
1572            cx: &mut Context<MultiBuffer>,
1573        ) {
1574            let (buffer_edits, edited_excerpt_ids) =
1575                MultiBuffer::convert_edits_to_buffer_edits(edits, this.snapshot.get_mut(), &[]);
1576
1577            let mut buffer_ids = Vec::new();
1578            for (buffer_id, mut edits) in buffer_edits {
1579                buffer_ids.push(buffer_id);
1580                edits.sort_unstable_by_key(|edit| edit.range.start);
1581
1582                let mut ranges: Vec<Range<BufferOffset>> = Vec::new();
1583                for edit in edits {
1584                    if let Some(last_range) = ranges.last_mut()
1585                        && edit.range.start <= last_range.end
1586                    {
1587                        last_range.end = last_range.end.max(edit.range.end);
1588                        continue;
1589                    }
1590                    ranges.push(edit.range);
1591                }
1592
1593                this.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1594                    buffer.autoindent_ranges(ranges, cx);
1595                })
1596            }
1597
1598            cx.emit(Event::ExcerptsEdited {
1599                excerpt_ids: edited_excerpt_ids,
1600                buffer_ids,
1601            });
1602        }
1603    }
1604
1605    pub fn set_active_selections(
1606        &self,
1607        selections: &[Selection<Anchor>],
1608        line_mode: bool,
1609        cursor_shape: CursorShape,
1610        cx: &mut Context<Self>,
1611    ) {
1612        let mut selections_by_buffer: HashMap<BufferId, Vec<Selection<text::Anchor>>> =
1613            Default::default();
1614        let snapshot = self.read(cx);
1615        let mut cursor = snapshot.excerpts.cursor::<Option<&Locator>>(());
1616        for selection in selections {
1617            let start_locator = snapshot.excerpt_locator_for_id(selection.start.excerpt_id);
1618            let end_locator = snapshot.excerpt_locator_for_id(selection.end.excerpt_id);
1619
1620            cursor.seek(&Some(start_locator), Bias::Left);
1621            while let Some(excerpt) = cursor.item()
1622                && excerpt.locator <= *end_locator
1623            {
1624                let mut start = excerpt.range.context.start;
1625                let mut end = excerpt.range.context.end;
1626                if excerpt.id == selection.start.excerpt_id {
1627                    start = selection.start.text_anchor;
1628                }
1629                if excerpt.id == selection.end.excerpt_id {
1630                    end = selection.end.text_anchor;
1631                }
1632                selections_by_buffer
1633                    .entry(excerpt.buffer_id)
1634                    .or_default()
1635                    .push(Selection {
1636                        id: selection.id,
1637                        start,
1638                        end,
1639                        reversed: selection.reversed,
1640                        goal: selection.goal,
1641                    });
1642
1643                cursor.next();
1644            }
1645        }
1646
1647        for (buffer_id, buffer_state) in self.buffers.iter() {
1648            if !selections_by_buffer.contains_key(buffer_id) {
1649                buffer_state
1650                    .buffer
1651                    .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
1652            }
1653        }
1654
1655        for (buffer_id, mut selections) in selections_by_buffer {
1656            self.buffers[&buffer_id].buffer.update(cx, |buffer, cx| {
1657                selections.sort_unstable_by(|a, b| a.start.cmp(&b.start, buffer));
1658                let mut selections = selections.into_iter().peekable();
1659                let merged_selections = Arc::from_iter(iter::from_fn(|| {
1660                    let mut selection = selections.next()?;
1661                    while let Some(next_selection) = selections.peek() {
1662                        if selection.end.cmp(&next_selection.start, buffer).is_ge() {
1663                            let next_selection = selections.next().unwrap();
1664                            if next_selection.end.cmp(&selection.end, buffer).is_ge() {
1665                                selection.end = next_selection.end;
1666                            }
1667                        } else {
1668                            break;
1669                        }
1670                    }
1671                    Some(selection)
1672                }));
1673                buffer.set_active_selections(merged_selections, line_mode, cursor_shape, cx);
1674            });
1675        }
1676    }
1677
1678    pub fn remove_active_selections(&self, cx: &mut Context<Self>) {
1679        for buffer in self.buffers.values() {
1680            buffer
1681                .buffer
1682                .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
1683        }
1684    }
1685
1686    pub fn push_excerpts<O>(
1687        &mut self,
1688        buffer: Entity<Buffer>,
1689        ranges: impl IntoIterator<Item = ExcerptRange<O>>,
1690        cx: &mut Context<Self>,
1691    ) -> Vec<ExcerptId>
1692    where
1693        O: text::ToOffset,
1694    {
1695        self.insert_excerpts_after(ExcerptId::max(), buffer, ranges, cx)
1696    }
1697
1698    #[instrument(skip_all)]
1699    fn merge_excerpt_ranges<'a>(
1700        expanded_ranges: impl IntoIterator<Item = &'a ExcerptRange<Point>> + 'a,
1701    ) -> (Vec<ExcerptRange<Point>>, Vec<usize>) {
1702        let mut merged_ranges: Vec<ExcerptRange<Point>> = Vec::new();
1703        let mut counts: Vec<usize> = Vec::new();
1704        for range in expanded_ranges {
1705            if let Some(last_range) = merged_ranges.last_mut() {
1706                assert!(
1707                    last_range.context.start <= range.context.start,
1708                    "ranges must be sorted: {last_range:?} <= {range:?}"
1709                );
1710                if last_range.context.end >= range.context.start
1711                    || last_range.context.end.row + 1 == range.context.start.row
1712                {
1713                    last_range.context.end = range.context.end.max(last_range.context.end);
1714                    *counts.last_mut().unwrap() += 1;
1715                    continue;
1716                }
1717            }
1718            merged_ranges.push(range.clone());
1719            counts.push(1);
1720        }
1721        (merged_ranges, counts)
1722    }
1723
1724    pub fn insert_excerpts_after<O>(
1725        &mut self,
1726        prev_excerpt_id: ExcerptId,
1727        buffer: Entity<Buffer>,
1728        ranges: impl IntoIterator<Item = ExcerptRange<O>>,
1729        cx: &mut Context<Self>,
1730    ) -> Vec<ExcerptId>
1731    where
1732        O: text::ToOffset,
1733    {
1734        let mut ids = Vec::new();
1735        let mut next_excerpt_id =
1736            if let Some(last_entry) = self.snapshot.borrow().excerpt_ids.last() {
1737                last_entry.id.0 + 1
1738            } else {
1739                1
1740            };
1741        self.insert_excerpts_with_ids_after(
1742            prev_excerpt_id,
1743            buffer,
1744            ranges.into_iter().map(|range| {
1745                let id = ExcerptId(post_inc(&mut next_excerpt_id));
1746                ids.push(id);
1747                (id, range)
1748            }),
1749            cx,
1750        );
1751        ids
1752    }
1753
1754    pub fn insert_excerpts_with_ids_after<O>(
1755        &mut self,
1756        prev_excerpt_id: ExcerptId,
1757        buffer: Entity<Buffer>,
1758        ranges: impl IntoIterator<Item = (ExcerptId, ExcerptRange<O>)>,
1759        cx: &mut Context<Self>,
1760    ) where
1761        O: text::ToOffset,
1762    {
1763        assert_eq!(self.history.transaction_depth(), 0);
1764        let mut ranges = ranges.into_iter().peekable();
1765        if ranges.peek().is_none() {
1766            return Default::default();
1767        }
1768
1769        self.sync_mut(cx);
1770
1771        let buffer_snapshot = buffer.read(cx).snapshot();
1772        let buffer_id = buffer_snapshot.remote_id();
1773
1774        let buffer_state = self.buffers.entry(buffer_id).or_insert_with(|| {
1775            self.buffer_changed_since_sync.replace(true);
1776            buffer.update(cx, |buffer, _| {
1777                buffer.record_changes(Rc::downgrade(&self.buffer_changed_since_sync));
1778            });
1779            BufferState {
1780                last_version: RefCell::new(buffer_snapshot.version().clone()),
1781                last_non_text_state_update_count: Cell::new(
1782                    buffer_snapshot.non_text_state_update_count(),
1783                ),
1784                excerpts: Default::default(),
1785                _subscriptions: [
1786                    cx.observe(&buffer, |_, _, cx| cx.notify()),
1787                    cx.subscribe(&buffer, Self::on_buffer_event),
1788                ],
1789                buffer: buffer.clone(),
1790            }
1791        });
1792
1793        let mut snapshot = self.snapshot.get_mut();
1794
1795        let mut prev_locator = snapshot.excerpt_locator_for_id(prev_excerpt_id).clone();
1796        let mut new_excerpt_ids = mem::take(&mut snapshot.excerpt_ids);
1797        let mut cursor = snapshot.excerpts.cursor::<Option<&Locator>>(());
1798        let mut new_excerpts = cursor.slice(&prev_locator, Bias::Right);
1799        prev_locator = cursor.start().unwrap_or(Locator::min_ref()).clone();
1800
1801        let edit_start = ExcerptDimension(new_excerpts.summary().text.len);
1802        new_excerpts.update_last(
1803            |excerpt| {
1804                excerpt.has_trailing_newline = true;
1805            },
1806            (),
1807        );
1808
1809        let next_locator = if let Some(excerpt) = cursor.item() {
1810            excerpt.locator.clone()
1811        } else {
1812            Locator::max()
1813        };
1814
1815        let mut excerpts = Vec::new();
1816        while let Some((id, range)) = ranges.next() {
1817            let locator = Locator::between(&prev_locator, &next_locator);
1818            if let Err(ix) = buffer_state.excerpts.binary_search(&locator) {
1819                buffer_state.excerpts.insert(ix, locator.clone());
1820            }
1821            let range = ExcerptRange {
1822                context: buffer_snapshot.anchor_before(&range.context.start)
1823                    ..buffer_snapshot.anchor_after(&range.context.end),
1824                primary: buffer_snapshot.anchor_before(&range.primary.start)
1825                    ..buffer_snapshot.anchor_after(&range.primary.end),
1826            };
1827            excerpts.push((id, range.clone()));
1828            let excerpt = Excerpt::new(
1829                id,
1830                locator.clone(),
1831                buffer_id,
1832                buffer_snapshot.clone(),
1833                range,
1834                ranges.peek().is_some() || cursor.item().is_some(),
1835            );
1836            new_excerpts.push(excerpt, ());
1837            prev_locator = locator.clone();
1838
1839            if let Some(last_mapping_entry) = new_excerpt_ids.last() {
1840                assert!(id > last_mapping_entry.id, "excerpt ids must be increasing");
1841            }
1842            new_excerpt_ids.push(ExcerptIdMapping { id, locator }, ());
1843        }
1844
1845        let edit_end = ExcerptDimension(new_excerpts.summary().text.len);
1846
1847        let suffix = cursor.suffix();
1848        let changed_trailing_excerpt = suffix.is_empty();
1849        new_excerpts.append(suffix, ());
1850        drop(cursor);
1851        snapshot.excerpts = new_excerpts;
1852        snapshot.excerpt_ids = new_excerpt_ids;
1853        if changed_trailing_excerpt {
1854            snapshot.trailing_excerpt_update_count += 1;
1855        }
1856
1857        let edits = Self::sync_diff_transforms(
1858            &mut snapshot,
1859            vec![Edit {
1860                old: edit_start..edit_start,
1861                new: edit_start..edit_end,
1862            }],
1863            DiffChangeKind::BufferEdited,
1864        );
1865        if !edits.is_empty() {
1866            self.subscriptions.publish(edits);
1867        }
1868
1869        cx.emit(Event::Edited {
1870            edited_buffer: None,
1871        });
1872        cx.emit(Event::ExcerptsAdded {
1873            buffer,
1874            predecessor: prev_excerpt_id,
1875            excerpts,
1876        });
1877        cx.notify();
1878    }
1879
1880    pub fn clear(&mut self, cx: &mut Context<Self>) {
1881        self.sync_mut(cx);
1882        let ids = self.excerpt_ids();
1883        let removed_buffer_ids = self.buffers.drain().map(|(id, _)| id).collect();
1884        self.excerpts_by_path.clear();
1885        self.paths_by_excerpt.clear();
1886        let MultiBufferSnapshot {
1887            excerpts,
1888            diffs: _,
1889            diff_transforms: _,
1890            non_text_state_update_count: _,
1891            edit_count: _,
1892            is_dirty,
1893            has_deleted_file,
1894            has_conflict,
1895            has_inverted_diff,
1896            singleton: _,
1897            excerpt_ids: _,
1898            replaced_excerpts,
1899            trailing_excerpt_update_count,
1900            all_diff_hunks_expanded: _,
1901            show_deleted_hunks: _,
1902            show_headers: _,
1903        } = self.snapshot.get_mut();
1904        let start = ExcerptDimension(MultiBufferOffset::ZERO);
1905        let prev_len = ExcerptDimension(excerpts.summary().text.len);
1906        *excerpts = Default::default();
1907        *trailing_excerpt_update_count += 1;
1908        *is_dirty = false;
1909        *has_deleted_file = false;
1910        *has_conflict = false;
1911        *has_inverted_diff = false;
1912        replaced_excerpts.clear();
1913
1914        let edits = Self::sync_diff_transforms(
1915            self.snapshot.get_mut(),
1916            vec![Edit {
1917                old: start..prev_len,
1918                new: start..start,
1919            }],
1920            DiffChangeKind::BufferEdited,
1921        );
1922        if !edits.is_empty() {
1923            self.subscriptions.publish(edits);
1924        }
1925        cx.emit(Event::Edited {
1926            edited_buffer: None,
1927        });
1928        cx.emit(Event::ExcerptsRemoved {
1929            ids,
1930            removed_buffer_ids,
1931        });
1932        cx.notify();
1933    }
1934
1935    #[ztracing::instrument(skip_all)]
1936    pub fn excerpts_for_buffer(
1937        &self,
1938        buffer_id: BufferId,
1939        cx: &App,
1940    ) -> Vec<(ExcerptId, ExcerptRange<text::Anchor>)> {
1941        let mut excerpts = Vec::new();
1942        let snapshot = self.read(cx);
1943        let mut cursor = snapshot.excerpts.cursor::<Option<&Locator>>(());
1944        if let Some(locators) = self.buffers.get(&buffer_id).map(|state| &state.excerpts) {
1945            for locator in locators {
1946                cursor.seek_forward(&Some(locator), Bias::Left);
1947                if let Some(excerpt) = cursor.item()
1948                    && excerpt.locator == *locator
1949                {
1950                    excerpts.push((excerpt.id, excerpt.range.clone()));
1951                }
1952            }
1953        }
1954
1955        excerpts
1956    }
1957
1958    pub fn excerpt_ranges_for_buffer(&self, buffer_id: BufferId, cx: &App) -> Vec<Range<Point>> {
1959        let snapshot = self.read(cx);
1960        let mut excerpts = snapshot
1961            .excerpts
1962            .cursor::<Dimensions<Option<&Locator>, ExcerptPoint>>(());
1963        let mut diff_transforms = snapshot
1964            .diff_transforms
1965            .cursor::<Dimensions<ExcerptPoint, OutputDimension<Point>>>(());
1966        diff_transforms.next();
1967        let locators = self
1968            .buffers
1969            .get(&buffer_id)
1970            .into_iter()
1971            .flat_map(|state| &state.excerpts);
1972        let mut result = Vec::new();
1973        for locator in locators {
1974            excerpts.seek_forward(&Some(locator), Bias::Left);
1975            if let Some(excerpt) = excerpts.item()
1976                && excerpt.locator == *locator
1977            {
1978                let excerpt_start = excerpts.start().1;
1979                let excerpt_end = excerpt_start + excerpt.text_summary.lines;
1980
1981                diff_transforms.seek_forward(&excerpt_start, Bias::Left);
1982                let overshoot = excerpt_start - diff_transforms.start().0;
1983                let start = diff_transforms.start().1 + overshoot;
1984
1985                diff_transforms.seek_forward(&excerpt_end, Bias::Right);
1986                let overshoot = excerpt_end - diff_transforms.start().0;
1987                let end = diff_transforms.start().1 + overshoot;
1988
1989                result.push(start.0..end.0)
1990            }
1991        }
1992        result
1993    }
1994
1995    pub fn excerpt_buffer_ids(&self) -> Vec<BufferId> {
1996        self.snapshot
1997            .borrow()
1998            .excerpts
1999            .iter()
2000            .map(|entry| entry.buffer_id)
2001            .collect()
2002    }
2003
2004    pub fn excerpt_ids(&self) -> Vec<ExcerptId> {
2005        self.snapshot
2006            .borrow()
2007            .excerpts
2008            .iter()
2009            .map(|entry| entry.id)
2010            .collect()
2011    }
2012
2013    pub fn excerpt_containing(
2014        &self,
2015        position: impl ToOffset,
2016        cx: &App,
2017    ) -> Option<(ExcerptId, Entity<Buffer>, Range<text::Anchor>)> {
2018        let snapshot = self.read(cx);
2019        let offset = position.to_offset(&snapshot);
2020
2021        let mut cursor = snapshot.cursor::<MultiBufferOffset, BufferOffset>();
2022        cursor.seek(&offset);
2023        cursor
2024            .excerpt()
2025            .or_else(|| snapshot.excerpts.last())
2026            .map(|excerpt| {
2027                (
2028                    excerpt.id,
2029                    self.buffers.get(&excerpt.buffer_id).unwrap().buffer.clone(),
2030                    excerpt.range.context.clone(),
2031                )
2032            })
2033    }
2034
2035    pub fn buffer_for_anchor(&self, anchor: Anchor, cx: &App) -> Option<Entity<Buffer>> {
2036        if let Some(buffer_id) = anchor.text_anchor.buffer_id {
2037            self.buffer(buffer_id)
2038        } else {
2039            let (_, buffer, _) = self.excerpt_containing(anchor, cx)?;
2040            Some(buffer)
2041        }
2042    }
2043
2044    // If point is at the end of the buffer, the last excerpt is returned
2045    pub fn point_to_buffer_offset<T: ToOffset>(
2046        &self,
2047        point: T,
2048        cx: &App,
2049    ) -> Option<(Entity<Buffer>, BufferOffset)> {
2050        let snapshot = self.read(cx);
2051        let (buffer, offset) = snapshot.point_to_buffer_offset(point)?;
2052        Some((
2053            self.buffers.get(&buffer.remote_id())?.buffer.clone(),
2054            offset,
2055        ))
2056    }
2057
2058    // If point is at the end of the buffer, the last excerpt is returned
2059    pub fn point_to_buffer_point<T: ToPoint>(
2060        &self,
2061        point: T,
2062        cx: &App,
2063    ) -> Option<(Entity<Buffer>, Point, ExcerptId)> {
2064        let snapshot = self.read(cx);
2065        let (buffer, point, is_main_buffer) =
2066            snapshot.point_to_buffer_point(point.to_point(&snapshot))?;
2067        Some((
2068            self.buffers.get(&buffer.remote_id())?.buffer.clone(),
2069            point,
2070            is_main_buffer,
2071        ))
2072    }
2073
2074    pub fn buffer_point_to_anchor(
2075        &self,
2076        buffer: &Entity<Buffer>,
2077        point: Point,
2078        cx: &App,
2079    ) -> Option<Anchor> {
2080        let mut found = None;
2081        let snapshot = buffer.read(cx).snapshot();
2082        for (excerpt_id, range) in self.excerpts_for_buffer(snapshot.remote_id(), cx) {
2083            let start = range.context.start.to_point(&snapshot);
2084            let end = range.context.end.to_point(&snapshot);
2085            if start <= point && point < end {
2086                found = Some((snapshot.clip_point(point, Bias::Left), excerpt_id));
2087                break;
2088            }
2089            if point < start {
2090                found = Some((start, excerpt_id));
2091            }
2092            if point > end {
2093                found = Some((end, excerpt_id));
2094            }
2095        }
2096
2097        found.map(|(point, excerpt_id)| {
2098            let text_anchor = snapshot.anchor_after(point);
2099            Anchor::in_buffer(excerpt_id, text_anchor)
2100        })
2101    }
2102
2103    pub fn buffer_anchor_to_anchor(
2104        &self,
2105        buffer: &Entity<Buffer>,
2106        anchor: text::Anchor,
2107        cx: &App,
2108    ) -> Option<Anchor> {
2109        let snapshot = buffer.read(cx).snapshot();
2110        for (excerpt_id, range) in self.excerpts_for_buffer(snapshot.remote_id(), cx) {
2111            if range.context.start.cmp(&anchor, &snapshot).is_le()
2112                && range.context.end.cmp(&anchor, &snapshot).is_ge()
2113            {
2114                return Some(Anchor::in_buffer(excerpt_id, anchor));
2115            }
2116        }
2117
2118        None
2119    }
2120
2121    pub fn remove_excerpts(
2122        &mut self,
2123        excerpt_ids: impl IntoIterator<Item = ExcerptId>,
2124        cx: &mut Context<Self>,
2125    ) {
2126        self.sync_mut(cx);
2127        let ids = excerpt_ids.into_iter().collect::<Vec<_>>();
2128        if ids.is_empty() {
2129            return;
2130        }
2131        self.buffer_changed_since_sync.replace(true);
2132
2133        let mut snapshot = self.snapshot.get_mut();
2134        let mut new_excerpts = SumTree::default();
2135        let mut cursor = snapshot
2136            .excerpts
2137            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2138        let mut edits = Vec::new();
2139        let mut excerpt_ids = ids.iter().copied().peekable();
2140        let mut removed_buffer_ids = Vec::new();
2141
2142        while let Some(excerpt_id) = excerpt_ids.next() {
2143            self.paths_by_excerpt.remove(&excerpt_id);
2144            // Seek to the next excerpt to remove, preserving any preceding excerpts.
2145            let locator = snapshot.excerpt_locator_for_id(excerpt_id);
2146            new_excerpts.append(cursor.slice(&Some(locator), Bias::Left), ());
2147
2148            if let Some(mut excerpt) = cursor.item() {
2149                if excerpt.id != excerpt_id {
2150                    continue;
2151                }
2152                let mut old_start = cursor.start().1;
2153
2154                // Skip over the removed excerpt.
2155                'remove_excerpts: loop {
2156                    if let Some(buffer_state) = self.buffers.get_mut(&excerpt.buffer_id) {
2157                        buffer_state.excerpts.retain(|l| l != &excerpt.locator);
2158                        if buffer_state.excerpts.is_empty() {
2159                            log::debug!(
2160                                "removing buffer and diff for buffer {}",
2161                                excerpt.buffer_id
2162                            );
2163                            self.buffers.remove(&excerpt.buffer_id);
2164                            removed_buffer_ids.push(excerpt.buffer_id);
2165                        }
2166                    }
2167                    cursor.next();
2168
2169                    // Skip over any subsequent excerpts that are also removed.
2170                    if let Some(&next_excerpt_id) = excerpt_ids.peek() {
2171                        let next_locator = snapshot.excerpt_locator_for_id(next_excerpt_id);
2172                        if let Some(next_excerpt) = cursor.item()
2173                            && next_excerpt.locator == *next_locator
2174                        {
2175                            excerpt_ids.next();
2176                            excerpt = next_excerpt;
2177                            continue 'remove_excerpts;
2178                        }
2179                    }
2180
2181                    break;
2182                }
2183
2184                // When removing the last excerpt, remove the trailing newline from
2185                // the previous excerpt.
2186                if cursor.item().is_none() && old_start > MultiBufferOffset::ZERO {
2187                    old_start -= 1;
2188                    new_excerpts.update_last(|e| e.has_trailing_newline = false, ());
2189                }
2190
2191                // Push an edit for the removal of this run of excerpts.
2192                let old_end = cursor.start().1;
2193                let new_start = ExcerptDimension(new_excerpts.summary().text.len);
2194                edits.push(Edit {
2195                    old: old_start..old_end,
2196                    new: new_start..new_start,
2197                });
2198            }
2199        }
2200        let suffix = cursor.suffix();
2201        let changed_trailing_excerpt = suffix.is_empty();
2202        new_excerpts.append(suffix, ());
2203        drop(cursor);
2204        snapshot.excerpts = new_excerpts;
2205        for buffer_id in &removed_buffer_ids {
2206            self.diffs.remove(buffer_id);
2207            snapshot.diffs.remove(buffer_id);
2208        }
2209
2210        // Recalculate has_inverted_diff after removing diffs
2211        if !removed_buffer_ids.is_empty() {
2212            snapshot.has_inverted_diff = snapshot
2213                .diffs
2214                .iter()
2215                .any(|(_, diff)| diff.main_buffer.is_some());
2216        }
2217
2218        if changed_trailing_excerpt {
2219            snapshot.trailing_excerpt_update_count += 1;
2220        }
2221
2222        let edits = Self::sync_diff_transforms(&mut snapshot, edits, DiffChangeKind::BufferEdited);
2223        if !edits.is_empty() {
2224            self.subscriptions.publish(edits);
2225        }
2226        cx.emit(Event::Edited {
2227            edited_buffer: None,
2228        });
2229        cx.emit(Event::ExcerptsRemoved {
2230            ids,
2231            removed_buffer_ids,
2232        });
2233        cx.notify();
2234    }
2235
2236    pub fn wait_for_anchors<'a, Anchors: 'a + Iterator<Item = Anchor>>(
2237        &self,
2238        anchors: Anchors,
2239        cx: &mut Context<Self>,
2240    ) -> impl 'static + Future<Output = Result<()>> + use<Anchors> {
2241        let mut error = None;
2242        let mut futures = Vec::new();
2243        for anchor in anchors {
2244            if let Some(buffer_id) = anchor.text_anchor.buffer_id {
2245                if let Some(buffer) = self.buffers.get(&buffer_id) {
2246                    buffer.buffer.update(cx, |buffer, _| {
2247                        futures.push(buffer.wait_for_anchors([anchor.text_anchor]))
2248                    });
2249                } else {
2250                    error = Some(anyhow!(
2251                        "buffer {buffer_id} is not part of this multi-buffer"
2252                    ));
2253                    break;
2254                }
2255            }
2256        }
2257        async move {
2258            if let Some(error) = error {
2259                Err(error)?;
2260            }
2261            for future in futures {
2262                future.await?;
2263            }
2264            Ok(())
2265        }
2266    }
2267
2268    pub fn text_anchor_for_position<T: ToOffset>(
2269        &self,
2270        position: T,
2271        cx: &App,
2272    ) -> Option<(Entity<Buffer>, language::Anchor)> {
2273        let snapshot = self.read(cx);
2274        let anchor = snapshot.anchor_before(position);
2275        let buffer = self
2276            .buffers
2277            .get(&anchor.text_anchor.buffer_id?)?
2278            .buffer
2279            .clone();
2280        Some((buffer, anchor.text_anchor))
2281    }
2282
2283    fn on_buffer_event(
2284        &mut self,
2285        buffer: Entity<Buffer>,
2286        event: &language::BufferEvent,
2287        cx: &mut Context<Self>,
2288    ) {
2289        use language::BufferEvent;
2290        let buffer_id = buffer.read(cx).remote_id();
2291        cx.emit(match event {
2292            BufferEvent::Edited => Event::Edited {
2293                edited_buffer: Some(buffer),
2294            },
2295            BufferEvent::DirtyChanged => Event::DirtyChanged,
2296            BufferEvent::Saved => Event::Saved,
2297            BufferEvent::FileHandleChanged => Event::FileHandleChanged,
2298            BufferEvent::Reloaded => Event::Reloaded,
2299            BufferEvent::LanguageChanged(has_language) => {
2300                Event::LanguageChanged(buffer_id, *has_language)
2301            }
2302            BufferEvent::Reparsed => Event::Reparsed(buffer_id),
2303            BufferEvent::DiagnosticsUpdated => Event::DiagnosticsUpdated,
2304            BufferEvent::CapabilityChanged => {
2305                self.capability = buffer.read(cx).capability();
2306                return;
2307            }
2308            BufferEvent::Operation { .. } | BufferEvent::ReloadNeeded => return,
2309        });
2310    }
2311
2312    fn buffer_diff_language_changed(&mut self, diff: Entity<BufferDiff>, cx: &mut Context<Self>) {
2313        let diff = diff.read(cx);
2314        let buffer_id = diff.buffer_id;
2315        let diff = DiffStateSnapshot {
2316            diff: diff.snapshot(cx),
2317            main_buffer: None,
2318        };
2319        self.snapshot.get_mut().diffs.insert(buffer_id, diff);
2320    }
2321
2322    fn inverted_buffer_diff_language_changed(
2323        &mut self,
2324        diff: Entity<BufferDiff>,
2325        main_buffer: WeakEntity<Buffer>,
2326        cx: &mut Context<Self>,
2327    ) {
2328        let base_text_buffer_id = diff.read(cx).base_text(cx).remote_id();
2329        let diff = diff.read(cx);
2330        let diff = DiffStateSnapshot {
2331            diff: diff.snapshot(cx),
2332            main_buffer: main_buffer
2333                .update(cx, |main_buffer, _| main_buffer.text_snapshot())
2334                .ok(),
2335        };
2336        self.snapshot
2337            .get_mut()
2338            .diffs
2339            .insert(base_text_buffer_id, diff);
2340    }
2341
2342    fn buffer_diff_changed(
2343        &mut self,
2344        diff: Entity<BufferDiff>,
2345        range: Range<text::Anchor>,
2346        cx: &mut Context<Self>,
2347    ) {
2348        self.sync_mut(cx);
2349
2350        let diff = diff.read(cx);
2351        let buffer_id = diff.buffer_id;
2352
2353        let Some(buffer_state) = self.buffers.get(&buffer_id) else {
2354            return;
2355        };
2356        let new_diff = DiffStateSnapshot {
2357            diff: diff.snapshot(cx),
2358            main_buffer: None,
2359        };
2360        let mut snapshot = self.snapshot.get_mut();
2361        let base_text_changed = snapshot
2362            .diffs
2363            .get(&buffer_id)
2364            .is_none_or(|old_diff| !new_diff.base_texts_definitely_eq(old_diff));
2365        snapshot.diffs.insert_or_replace(buffer_id, new_diff);
2366        self.buffer_changed_since_sync.replace(true);
2367
2368        let buffer = buffer_state.buffer.read(cx);
2369        let diff_change_range = range.to_offset(buffer);
2370
2371        let excerpt_edits = snapshot.excerpt_edits_for_diff_change(buffer_state, diff_change_range);
2372        let edits = Self::sync_diff_transforms(
2373            &mut snapshot,
2374            excerpt_edits,
2375            DiffChangeKind::DiffUpdated {
2376                base_changed: base_text_changed,
2377            },
2378        );
2379        if !edits.is_empty() {
2380            self.subscriptions.publish(edits);
2381        }
2382        cx.emit(Event::Edited {
2383            edited_buffer: None,
2384        });
2385    }
2386
2387    fn inverted_buffer_diff_changed(
2388        &mut self,
2389        diff: Entity<BufferDiff>,
2390        diff_change_range: Range<usize>,
2391        main_buffer: WeakEntity<Buffer>,
2392        cx: &mut Context<Self>,
2393    ) {
2394        self.sync_mut(cx);
2395
2396        let diff = diff.read(cx);
2397        let base_text_buffer_id = diff.base_text(cx).remote_id();
2398        let Some(buffer_state) = self.buffers.get(&base_text_buffer_id) else {
2399            return;
2400        };
2401        self.buffer_changed_since_sync.replace(true);
2402
2403        let new_diff = DiffStateSnapshot {
2404            diff: diff.snapshot(cx),
2405            main_buffer: main_buffer
2406                .update(cx, |main_buffer, _| main_buffer.text_snapshot())
2407                .ok(),
2408        };
2409        let mut snapshot = self.snapshot.get_mut();
2410        snapshot
2411            .diffs
2412            .insert_or_replace(base_text_buffer_id, new_diff);
2413
2414        let excerpt_edits = snapshot.excerpt_edits_for_diff_change(buffer_state, diff_change_range);
2415        let edits = Self::sync_diff_transforms(
2416            &mut snapshot,
2417            excerpt_edits,
2418            DiffChangeKind::DiffUpdated {
2419                // We don't use read this field for inverted diffs.
2420                base_changed: false,
2421            },
2422        );
2423        if !edits.is_empty() {
2424            self.subscriptions.publish(edits);
2425        }
2426        cx.emit(Event::Edited {
2427            edited_buffer: None,
2428        });
2429    }
2430
2431    pub fn all_buffers_iter(&self) -> impl Iterator<Item = Entity<Buffer>> {
2432        self.buffers.values().map(|state| state.buffer.clone())
2433    }
2434
2435    pub fn all_buffers(&self) -> HashSet<Entity<Buffer>> {
2436        self.all_buffers_iter().collect()
2437    }
2438
2439    pub fn all_buffer_ids_iter(&self) -> impl Iterator<Item = BufferId> {
2440        self.buffers.keys().copied()
2441    }
2442
2443    pub fn all_buffer_ids(&self) -> Vec<BufferId> {
2444        self.all_buffer_ids_iter().collect()
2445    }
2446
2447    pub fn buffer(&self, buffer_id: BufferId) -> Option<Entity<Buffer>> {
2448        self.buffers
2449            .get(&buffer_id)
2450            .map(|state| state.buffer.clone())
2451    }
2452
2453    pub fn language_at<T: ToOffset>(&self, point: T, cx: &App) -> Option<Arc<Language>> {
2454        self.point_to_buffer_offset(point, cx)
2455            .and_then(|(buffer, offset)| buffer.read(cx).language_at(offset))
2456    }
2457
2458    pub fn language_settings<'a>(&'a self, cx: &'a App) -> Cow<'a, LanguageSettings> {
2459        let buffer_id = self
2460            .snapshot
2461            .borrow()
2462            .excerpts
2463            .first()
2464            .map(|excerpt| excerpt.buffer.remote_id());
2465        buffer_id
2466            .and_then(|buffer_id| self.buffer(buffer_id))
2467            .map(|buffer| {
2468                let buffer = buffer.read(cx);
2469                language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx)
2470            })
2471            .unwrap_or_else(move || self.language_settings_at(MultiBufferOffset::default(), cx))
2472    }
2473
2474    pub fn language_settings_at<'a, T: ToOffset>(
2475        &'a self,
2476        point: T,
2477        cx: &'a App,
2478    ) -> Cow<'a, LanguageSettings> {
2479        let mut language = None;
2480        let mut file = None;
2481        if let Some((buffer, offset)) = self.point_to_buffer_offset(point, cx) {
2482            let buffer = buffer.read(cx);
2483            language = buffer.language_at(offset);
2484            file = buffer.file();
2485        }
2486        language_settings(language.map(|l| l.name()), file, cx)
2487    }
2488
2489    pub fn for_each_buffer(&self, mut f: impl FnMut(&Entity<Buffer>)) {
2490        self.buffers.values().for_each(|state| f(&state.buffer))
2491    }
2492
2493    pub fn explicit_title(&self) -> Option<&str> {
2494        self.title.as_deref()
2495    }
2496
2497    pub fn title<'a>(&'a self, cx: &'a App) -> Cow<'a, str> {
2498        if let Some(title) = self.title.as_ref() {
2499            return title.into();
2500        }
2501
2502        if let Some(buffer) = self.as_singleton() {
2503            let buffer = buffer.read(cx);
2504
2505            if let Some(file) = buffer.file() {
2506                return file.file_name(cx).into();
2507            }
2508
2509            if let Some(title) = self.buffer_content_title(buffer) {
2510                return title;
2511            }
2512        };
2513
2514        "untitled".into()
2515    }
2516
2517    fn buffer_content_title(&self, buffer: &Buffer) -> Option<Cow<'_, str>> {
2518        let mut is_leading_whitespace = true;
2519        let mut count = 0;
2520        let mut prev_was_space = false;
2521        let mut title = String::new();
2522
2523        for ch in buffer.snapshot().chars() {
2524            if is_leading_whitespace && ch.is_whitespace() {
2525                continue;
2526            }
2527
2528            is_leading_whitespace = false;
2529
2530            if ch == '\n' || count >= 40 {
2531                break;
2532            }
2533
2534            if ch.is_whitespace() {
2535                if !prev_was_space {
2536                    title.push(' ');
2537                    count += 1;
2538                    prev_was_space = true;
2539                }
2540            } else {
2541                title.push(ch);
2542                count += 1;
2543                prev_was_space = false;
2544            }
2545        }
2546
2547        let title = title.trim_end().to_string();
2548
2549        if title.is_empty() {
2550            return None;
2551        }
2552
2553        Some(title.into())
2554    }
2555
2556    pub fn set_title(&mut self, title: String, cx: &mut Context<Self>) {
2557        self.title = Some(title);
2558        cx.notify();
2559    }
2560
2561    /// Preserve preview tabs containing this multibuffer until additional edits occur.
2562    pub fn refresh_preview(&self, cx: &mut Context<Self>) {
2563        for buffer_state in self.buffers.values() {
2564            buffer_state
2565                .buffer
2566                .update(cx, |buffer, _cx| buffer.refresh_preview());
2567        }
2568    }
2569
2570    /// Whether we should preserve the preview status of a tab containing this multi-buffer.
2571    pub fn preserve_preview(&self, cx: &App) -> bool {
2572        self.buffers
2573            .values()
2574            .all(|state| state.buffer.read(cx).preserve_preview())
2575    }
2576
2577    #[cfg(any(test, feature = "test-support"))]
2578    pub fn is_parsing(&self, cx: &App) -> bool {
2579        self.as_singleton().unwrap().read(cx).is_parsing()
2580    }
2581
2582    pub fn add_diff(&mut self, diff: Entity<BufferDiff>, cx: &mut Context<Self>) {
2583        let buffer_id = diff.read(cx).buffer_id;
2584        self.buffer_diff_changed(
2585            diff.clone(),
2586            text::Anchor::min_max_range_for_buffer(buffer_id),
2587            cx,
2588        );
2589        self.diffs.insert(buffer_id, DiffState::new(diff, cx));
2590    }
2591
2592    pub fn add_inverted_diff(
2593        &mut self,
2594        diff: Entity<BufferDiff>,
2595        main_buffer: Entity<Buffer>,
2596        cx: &mut Context<Self>,
2597    ) {
2598        let base_text_buffer_id = diff.read(cx).base_text(cx).remote_id();
2599        let diff_change_range = 0..diff.read(cx).base_text(cx).len();
2600        self.snapshot.get_mut().has_inverted_diff = true;
2601        main_buffer.update(cx, |buffer, _| {
2602            buffer.record_changes(Rc::downgrade(&self.buffer_changed_since_sync));
2603        });
2604        self.inverted_buffer_diff_changed(
2605            diff.clone(),
2606            diff_change_range,
2607            main_buffer.downgrade(),
2608            cx,
2609        );
2610        self.diffs.insert(
2611            base_text_buffer_id,
2612            DiffState::new_inverted(diff, main_buffer, cx),
2613        );
2614    }
2615
2616    pub fn diff_for(&self, buffer_id: BufferId) -> Option<Entity<BufferDiff>> {
2617        self.diffs.get(&buffer_id).map(|state| state.diff.clone())
2618    }
2619
2620    pub fn expand_diff_hunks(&mut self, ranges: Vec<Range<Anchor>>, cx: &mut Context<Self>) {
2621        self.expand_or_collapse_diff_hunks(ranges, true, cx);
2622    }
2623
2624    pub fn collapse_diff_hunks(&mut self, ranges: Vec<Range<Anchor>>, cx: &mut Context<Self>) {
2625        self.expand_or_collapse_diff_hunks(ranges, false, cx);
2626    }
2627
2628    pub fn set_all_diff_hunks_expanded(&mut self, cx: &mut Context<Self>) {
2629        self.snapshot.get_mut().all_diff_hunks_expanded = true;
2630        self.expand_or_collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], true, cx);
2631    }
2632
2633    pub fn all_diff_hunks_expanded(&self) -> bool {
2634        self.snapshot.borrow().all_diff_hunks_expanded
2635    }
2636
2637    pub fn set_all_diff_hunks_collapsed(&mut self, cx: &mut Context<Self>) {
2638        self.snapshot.get_mut().all_diff_hunks_expanded = false;
2639        self.expand_or_collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], false, cx);
2640    }
2641
2642    pub fn set_show_deleted_hunks(&mut self, show: bool, cx: &mut Context<Self>) {
2643        self.snapshot.get_mut().show_deleted_hunks = show;
2644        self.expand_or_collapse_diff_hunks(vec![Anchor::min()..Anchor::max()], true, cx);
2645    }
2646
2647    pub fn has_multiple_hunks(&self, cx: &App) -> bool {
2648        self.read(cx)
2649            .diff_hunks_in_range(Anchor::min()..Anchor::max())
2650            .nth(1)
2651            .is_some()
2652    }
2653
2654    pub fn single_hunk_is_expanded(&self, range: Range<Anchor>, cx: &App) -> bool {
2655        let snapshot = self.read(cx);
2656        let mut cursor = snapshot.diff_transforms.cursor::<MultiBufferOffset>(());
2657        let offset_range = range.to_offset(&snapshot);
2658        cursor.seek(&offset_range.start, Bias::Left);
2659        while let Some(item) = cursor.item() {
2660            if *cursor.start() >= offset_range.end && *cursor.start() > offset_range.start {
2661                break;
2662            }
2663            if item.hunk_info().is_some() {
2664                return true;
2665            }
2666            cursor.next();
2667        }
2668        false
2669    }
2670
2671    pub fn has_expanded_diff_hunks_in_ranges(&self, ranges: &[Range<Anchor>], cx: &App) -> bool {
2672        let snapshot = self.read(cx);
2673        let mut cursor = snapshot.diff_transforms.cursor::<MultiBufferOffset>(());
2674        for range in ranges {
2675            let range = range.to_point(&snapshot);
2676            let start = snapshot.point_to_offset(Point::new(range.start.row, 0));
2677            let end = (snapshot.point_to_offset(Point::new(range.end.row + 1, 0)) + 1usize)
2678                .min(snapshot.len());
2679            cursor.seek(&start, Bias::Right);
2680            while let Some(item) = cursor.item() {
2681                if *cursor.start() >= end {
2682                    break;
2683                }
2684                if item.hunk_info().is_some() {
2685                    return true;
2686                }
2687                cursor.next();
2688            }
2689        }
2690        false
2691    }
2692
2693    pub fn expand_or_collapse_diff_hunks_inner(
2694        &mut self,
2695        ranges: impl IntoIterator<Item = (Range<Point>, ExcerptId)>,
2696        expand: bool,
2697        cx: &mut Context<Self>,
2698    ) {
2699        if self.snapshot.borrow().all_diff_hunks_expanded && !expand {
2700            return;
2701        }
2702        self.sync_mut(cx);
2703        let mut snapshot = self.snapshot.get_mut();
2704        let mut excerpt_edits = Vec::new();
2705        let mut last_hunk_row = None;
2706        for (range, end_excerpt_id) in ranges {
2707            for diff_hunk in snapshot.diff_hunks_in_range(range) {
2708                if diff_hunk.excerpt_id.cmp(&end_excerpt_id, &snapshot).is_gt() {
2709                    continue;
2710                }
2711                if last_hunk_row.is_some_and(|row| row >= diff_hunk.row_range.start) {
2712                    continue;
2713                }
2714                let start = Anchor::in_buffer(diff_hunk.excerpt_id, diff_hunk.buffer_range.start);
2715                let end = Anchor::in_buffer(diff_hunk.excerpt_id, diff_hunk.buffer_range.end);
2716                let start = snapshot.excerpt_offset_for_anchor(&start);
2717                let end = snapshot.excerpt_offset_for_anchor(&end);
2718                last_hunk_row = Some(diff_hunk.row_range.start);
2719                excerpt_edits.push(text::Edit {
2720                    old: start..end,
2721                    new: start..end,
2722                });
2723            }
2724        }
2725
2726        let edits = Self::sync_diff_transforms(
2727            &mut snapshot,
2728            excerpt_edits,
2729            DiffChangeKind::ExpandOrCollapseHunks { expand },
2730        );
2731        if !edits.is_empty() {
2732            self.subscriptions.publish(edits);
2733        }
2734        cx.emit(Event::DiffHunksToggled);
2735        cx.emit(Event::Edited {
2736            edited_buffer: None,
2737        });
2738    }
2739
2740    pub fn expand_or_collapse_diff_hunks(
2741        &mut self,
2742        ranges: Vec<Range<Anchor>>,
2743        expand: bool,
2744        cx: &mut Context<Self>,
2745    ) {
2746        let snapshot = self.snapshot.borrow().clone();
2747        let ranges = ranges.iter().map(move |range| {
2748            let end_excerpt_id = range.end.excerpt_id;
2749            let range = range.to_point(&snapshot);
2750            let mut peek_end = range.end;
2751            if range.end.row < snapshot.max_row().0 {
2752                peek_end = Point::new(range.end.row + 1, 0);
2753            };
2754            (range.start..peek_end, end_excerpt_id)
2755        });
2756        self.expand_or_collapse_diff_hunks_inner(ranges, expand, cx);
2757    }
2758
2759    pub fn resize_excerpt(
2760        &mut self,
2761        id: ExcerptId,
2762        range: Range<text::Anchor>,
2763        cx: &mut Context<Self>,
2764    ) {
2765        self.sync_mut(cx);
2766
2767        let mut snapshot = self.snapshot.get_mut();
2768        let locator = snapshot.excerpt_locator_for_id(id);
2769        let mut new_excerpts = SumTree::default();
2770        let mut cursor = snapshot
2771            .excerpts
2772            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2773        let mut edits = Vec::<Edit<ExcerptOffset>>::new();
2774
2775        let prefix = cursor.slice(&Some(locator), Bias::Left);
2776        new_excerpts.append(prefix, ());
2777
2778        let mut excerpt = cursor.item().unwrap().clone();
2779        let old_text_len = excerpt.text_summary.len;
2780
2781        excerpt.range.context.start = range.start;
2782        excerpt.range.context.end = range.end;
2783        excerpt.max_buffer_row = range.end.to_point(&excerpt.buffer).row;
2784
2785        excerpt.text_summary = excerpt
2786            .buffer
2787            .text_summary_for_range(excerpt.range.context.clone());
2788
2789        let new_start_offset = ExcerptDimension(new_excerpts.summary().text.len);
2790        let old_start_offset = cursor.start().1;
2791        let new_text_len = excerpt.text_summary.len;
2792        let edit = Edit {
2793            old: old_start_offset..old_start_offset + old_text_len,
2794            new: new_start_offset..new_start_offset + new_text_len,
2795        };
2796
2797        if let Some(last_edit) = edits.last_mut() {
2798            if last_edit.old.end == edit.old.start {
2799                last_edit.old.end = edit.old.end;
2800                last_edit.new.end = edit.new.end;
2801            } else {
2802                edits.push(edit);
2803            }
2804        } else {
2805            edits.push(edit);
2806        }
2807
2808        new_excerpts.push(excerpt, ());
2809
2810        cursor.next();
2811
2812        new_excerpts.append(cursor.suffix(), ());
2813
2814        drop(cursor);
2815        snapshot.excerpts = new_excerpts;
2816
2817        let edits = Self::sync_diff_transforms(&mut snapshot, edits, DiffChangeKind::BufferEdited);
2818        if !edits.is_empty() {
2819            self.subscriptions.publish(edits);
2820        }
2821        cx.emit(Event::Edited {
2822            edited_buffer: None,
2823        });
2824        cx.emit(Event::ExcerptsExpanded { ids: vec![id] });
2825        cx.notify();
2826    }
2827
2828    pub fn expand_excerpts(
2829        &mut self,
2830        ids: impl IntoIterator<Item = ExcerptId>,
2831        line_count: u32,
2832        direction: ExpandExcerptDirection,
2833        cx: &mut Context<Self>,
2834    ) {
2835        if line_count == 0 {
2836            return;
2837        }
2838        self.sync_mut(cx);
2839        if !self.excerpts_by_path.is_empty() {
2840            self.expand_excerpts_with_paths(ids, line_count, direction, cx);
2841            return;
2842        }
2843        let mut snapshot = self.snapshot.get_mut();
2844
2845        let ids = ids.into_iter().collect::<Vec<_>>();
2846        let locators = snapshot.excerpt_locators_for_ids(ids.iter().copied());
2847        let mut new_excerpts = SumTree::default();
2848        let mut cursor = snapshot
2849            .excerpts
2850            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
2851        let mut edits = Vec::<Edit<ExcerptOffset>>::new();
2852
2853        for locator in &locators {
2854            let prefix = cursor.slice(&Some(locator), Bias::Left);
2855            new_excerpts.append(prefix, ());
2856
2857            let mut excerpt = cursor.item().unwrap().clone();
2858            let old_text_len = excerpt.text_summary.len;
2859
2860            let up_line_count = if direction.should_expand_up() {
2861                line_count
2862            } else {
2863                0
2864            };
2865
2866            let start_row = excerpt
2867                .range
2868                .context
2869                .start
2870                .to_point(&excerpt.buffer)
2871                .row
2872                .saturating_sub(up_line_count);
2873            let start_point = Point::new(start_row, 0);
2874            excerpt.range.context.start = excerpt.buffer.anchor_before(start_point);
2875
2876            let down_line_count = if direction.should_expand_down() {
2877                line_count
2878            } else {
2879                0
2880            };
2881
2882            let mut end_point = excerpt.buffer.clip_point(
2883                excerpt.range.context.end.to_point(&excerpt.buffer)
2884                    + Point::new(down_line_count, 0),
2885                Bias::Left,
2886            );
2887            end_point.column = excerpt.buffer.line_len(end_point.row);
2888            excerpt.range.context.end = excerpt.buffer.anchor_after(end_point);
2889            excerpt.max_buffer_row = end_point.row;
2890
2891            excerpt.text_summary = excerpt
2892                .buffer
2893                .text_summary_for_range(excerpt.range.context.clone());
2894
2895            let new_start_offset = ExcerptDimension(new_excerpts.summary().text.len);
2896            let old_start_offset = cursor.start().1;
2897            let new_text_len = excerpt.text_summary.len;
2898            let edit = Edit {
2899                old: old_start_offset..old_start_offset + old_text_len,
2900                new: new_start_offset..new_start_offset + new_text_len,
2901            };
2902
2903            if let Some(last_edit) = edits.last_mut() {
2904                if last_edit.old.end == edit.old.start {
2905                    last_edit.old.end = edit.old.end;
2906                    last_edit.new.end = edit.new.end;
2907                } else {
2908                    edits.push(edit);
2909                }
2910            } else {
2911                edits.push(edit);
2912            }
2913
2914            new_excerpts.push(excerpt, ());
2915
2916            cursor.next();
2917        }
2918
2919        new_excerpts.append(cursor.suffix(), ());
2920
2921        drop(cursor);
2922        snapshot.excerpts = new_excerpts;
2923
2924        let edits = Self::sync_diff_transforms(&mut snapshot, edits, DiffChangeKind::BufferEdited);
2925        if !edits.is_empty() {
2926            self.subscriptions.publish(edits);
2927        }
2928        cx.emit(Event::Edited {
2929            edited_buffer: None,
2930        });
2931        cx.emit(Event::ExcerptsExpanded { ids });
2932        cx.notify();
2933    }
2934
2935    #[ztracing::instrument(skip_all)]
2936    fn sync(&self, cx: &App) {
2937        let changed = self.buffer_changed_since_sync.replace(false);
2938        if !changed {
2939            return;
2940        }
2941        let edits = Self::sync_from_buffer_changes(
2942            &mut self.snapshot.borrow_mut(),
2943            &self.buffers,
2944            &self.diffs,
2945            cx,
2946        );
2947        if !edits.is_empty() {
2948            self.subscriptions.publish(edits);
2949        }
2950    }
2951
2952    fn sync_mut(&mut self, cx: &App) {
2953        let changed = self.buffer_changed_since_sync.replace(false);
2954        if !changed {
2955            return;
2956        }
2957        let edits =
2958            Self::sync_from_buffer_changes(self.snapshot.get_mut(), &self.buffers, &self.diffs, cx);
2959
2960        if !edits.is_empty() {
2961            self.subscriptions.publish(edits);
2962        }
2963    }
2964
2965    fn sync_from_buffer_changes(
2966        snapshot: &mut MultiBufferSnapshot,
2967        buffers: &HashMap<BufferId, BufferState>,
2968        diffs: &HashMap<BufferId, DiffState>,
2969        cx: &App,
2970    ) -> Vec<Edit<MultiBufferOffset>> {
2971        let MultiBufferSnapshot {
2972            excerpts,
2973            diffs: buffer_diff,
2974            diff_transforms: _,
2975            non_text_state_update_count,
2976            edit_count,
2977            is_dirty,
2978            has_deleted_file,
2979            has_conflict,
2980            has_inverted_diff: _,
2981            singleton: _,
2982            excerpt_ids: _,
2983            replaced_excerpts: _,
2984            trailing_excerpt_update_count: _,
2985            all_diff_hunks_expanded: _,
2986            show_deleted_hunks: _,
2987            show_headers: _,
2988        } = snapshot;
2989        *is_dirty = false;
2990        *has_deleted_file = false;
2991        *has_conflict = false;
2992
2993        let mut excerpts_to_edit = Vec::new();
2994        let mut non_text_state_updated = false;
2995        let mut edited = false;
2996        for buffer_state in buffers.values() {
2997            let buffer = buffer_state.buffer.read(cx);
2998            let version = buffer.version();
2999            let non_text_state_update_count = buffer.non_text_state_update_count();
3000
3001            let buffer_edited = version.changed_since(&buffer_state.last_version.borrow());
3002            let buffer_non_text_state_updated =
3003                non_text_state_update_count > buffer_state.last_non_text_state_update_count.get();
3004            if buffer_edited || buffer_non_text_state_updated {
3005                *buffer_state.last_version.borrow_mut() = version;
3006                buffer_state
3007                    .last_non_text_state_update_count
3008                    .set(non_text_state_update_count);
3009                excerpts_to_edit.extend(
3010                    buffer_state
3011                        .excerpts
3012                        .iter()
3013                        .map(|locator| (locator, buffer_state.buffer.clone(), buffer_edited)),
3014                );
3015            }
3016
3017            edited |= buffer_edited;
3018            non_text_state_updated |= buffer_non_text_state_updated;
3019            *is_dirty |= buffer.is_dirty();
3020            *has_deleted_file |= buffer
3021                .file()
3022                .is_some_and(|file| file.disk_state().is_deleted());
3023            *has_conflict |= buffer.has_conflict();
3024        }
3025        if edited {
3026            *edit_count += 1;
3027        }
3028        if non_text_state_updated {
3029            *non_text_state_update_count += 1;
3030        }
3031
3032        for (id, diff) in diffs.iter() {
3033            if buffer_diff.get(id).is_none() {
3034                buffer_diff.insert(*id, diff.snapshot(cx));
3035            }
3036        }
3037
3038        // Check for main buffer changes in inverted diffs
3039        let mut main_buffer_changed_diffs = Vec::new();
3040        for (id, diff_state) in diffs.iter() {
3041            if let Some(main_buffer) = &diff_state.main_buffer {
3042                if let Ok(current_main_buffer) =
3043                    main_buffer.read_with(cx, |buffer, _| buffer.text_snapshot())
3044                {
3045                    if let Some(stored_diff) = buffer_diff.get(id) {
3046                        if let Some(stored_main_buffer) = &stored_diff.main_buffer {
3047                            if current_main_buffer
3048                                .version()
3049                                .changed_since(stored_main_buffer.version())
3050                            {
3051                                main_buffer_changed_diffs.push((
3052                                    *id,
3053                                    stored_diff.clone(),
3054                                    current_main_buffer,
3055                                ));
3056                            }
3057                        }
3058                    }
3059                }
3060            }
3061        }
3062
3063        let mut inverted_diff_touch_info: HashMap<
3064            Locator,
3065            (
3066                BufferDiffSnapshot,
3067                text::BufferSnapshot,
3068                text::BufferSnapshot,
3069            ),
3070        > = HashMap::default();
3071        for (buffer_id, old_diff_snapshot, new_main_buffer) in &main_buffer_changed_diffs {
3072            if let Some(old_main_buffer) = &old_diff_snapshot.main_buffer {
3073                if let Some(buffer_state) = buffers.get(buffer_id) {
3074                    for locator in &buffer_state.excerpts {
3075                        inverted_diff_touch_info.insert(
3076                            locator.clone(),
3077                            (
3078                                old_diff_snapshot.diff.clone(),
3079                                old_main_buffer.clone(),
3080                                new_main_buffer.clone(),
3081                            ),
3082                        );
3083                        excerpts_to_edit.push((locator, buffer_state.buffer.clone(), false));
3084                    }
3085                }
3086            }
3087        }
3088
3089        excerpts_to_edit.sort_unstable_by_key(|(locator, _, _)| *locator);
3090        excerpts_to_edit.dedup_by(|a, b| {
3091            if a.0 == b.0 {
3092                b.2 |= a.2;
3093                true
3094            } else {
3095                false
3096            }
3097        });
3098
3099        let mut edits = Vec::new();
3100        let mut new_excerpts = SumTree::default();
3101        let mut cursor = excerpts.cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
3102
3103        for (locator, buffer, buffer_edited) in excerpts_to_edit {
3104            new_excerpts.append(cursor.slice(&Some(locator), Bias::Left), ());
3105            let old_excerpt = cursor.item().unwrap();
3106            let buffer = buffer.read(cx);
3107            let buffer_id = buffer.remote_id();
3108
3109            let excerpt_old_start = cursor.start().1;
3110            let excerpt_new_start = ExcerptDimension(new_excerpts.summary().text.len);
3111
3112            if !buffer_edited
3113                && let Some((old_diff, old_main_buffer, new_main_buffer)) =
3114                    inverted_diff_touch_info.get(locator)
3115            {
3116                let excerpt_buffer_start = old_excerpt
3117                    .range
3118                    .context
3119                    .start
3120                    .to_offset(&old_excerpt.buffer);
3121                let excerpt_buffer_end = excerpt_buffer_start + old_excerpt.text_summary.len;
3122
3123                for hunk in old_diff.hunks_intersecting_base_text_range(
3124                    excerpt_buffer_start..excerpt_buffer_end,
3125                    old_main_buffer,
3126                ) {
3127                    if hunk.buffer_range.start.is_valid(new_main_buffer) {
3128                        continue;
3129                    }
3130                    let hunk_buffer_start = hunk.diff_base_byte_range.start;
3131                    if hunk_buffer_start >= excerpt_buffer_start
3132                        && hunk_buffer_start <= excerpt_buffer_end
3133                    {
3134                        let hunk_offset = hunk_buffer_start - excerpt_buffer_start;
3135                        let old_hunk_pos = excerpt_old_start + hunk_offset;
3136                        let new_hunk_pos = excerpt_new_start + hunk_offset;
3137                        edits.push(Edit {
3138                            old: old_hunk_pos..old_hunk_pos,
3139                            new: new_hunk_pos..new_hunk_pos,
3140                        });
3141                    }
3142                }
3143            }
3144
3145            let mut new_excerpt;
3146            if buffer_edited {
3147                edits.extend(
3148                    buffer
3149                        .edits_since_in_range::<usize>(
3150                            old_excerpt.buffer.version(),
3151                            old_excerpt.range.context.clone(),
3152                        )
3153                        .map(|edit| {
3154                            let excerpt_old_start = cursor.start().1;
3155                            let excerpt_new_start =
3156                                ExcerptDimension(new_excerpts.summary().text.len);
3157                            let old_start = excerpt_old_start + edit.old.start;
3158                            let old_end = excerpt_old_start + edit.old.end;
3159                            let new_start = excerpt_new_start + edit.new.start;
3160                            let new_end = excerpt_new_start + edit.new.end;
3161                            Edit {
3162                                old: old_start..old_end,
3163                                new: new_start..new_end,
3164                            }
3165                        }),
3166                );
3167
3168                new_excerpt = Excerpt::new(
3169                    old_excerpt.id,
3170                    locator.clone(),
3171                    buffer_id,
3172                    buffer.snapshot(),
3173                    old_excerpt.range.clone(),
3174                    old_excerpt.has_trailing_newline,
3175                );
3176            } else {
3177                new_excerpt = old_excerpt.clone();
3178                new_excerpt.buffer = buffer.snapshot();
3179            }
3180
3181            new_excerpts.push(new_excerpt, ());
3182            cursor.next();
3183        }
3184        new_excerpts.append(cursor.suffix(), ());
3185
3186        drop(cursor);
3187        *excerpts = new_excerpts;
3188
3189        for (buffer_id, _, new_main_buffer) in main_buffer_changed_diffs {
3190            if let Some(stored) = buffer_diff.get(&buffer_id) {
3191                let mut updated = stored.clone();
3192                updated.main_buffer = Some(new_main_buffer);
3193                buffer_diff.insert(buffer_id, updated);
3194            }
3195        }
3196
3197        Self::sync_diff_transforms(snapshot, edits, DiffChangeKind::BufferEdited)
3198    }
3199
3200    fn sync_diff_transforms(
3201        snapshot: &mut MultiBufferSnapshot,
3202        excerpt_edits: Vec<text::Edit<ExcerptOffset>>,
3203        change_kind: DiffChangeKind,
3204    ) -> Vec<Edit<MultiBufferOffset>> {
3205        if excerpt_edits.is_empty() {
3206            return vec![];
3207        }
3208
3209        let mut excerpts = snapshot.excerpts.cursor::<ExcerptOffset>(());
3210        let mut old_diff_transforms = snapshot
3211            .diff_transforms
3212            .cursor::<Dimensions<ExcerptOffset, MultiBufferOffset>>(());
3213        let mut new_diff_transforms = SumTree::default();
3214        let mut old_expanded_hunks = HashSet::default();
3215        let mut output_edits = Vec::new();
3216        let mut output_delta = 0_isize;
3217        let mut at_transform_boundary = true;
3218        let mut end_of_current_insert = None;
3219
3220        let mut excerpt_edits = excerpt_edits.into_iter().peekable();
3221        while let Some(edit) = excerpt_edits.next() {
3222            excerpts.seek_forward(&edit.new.start, Bias::Right);
3223            if excerpts.item().is_none() && *excerpts.start() == edit.new.start {
3224                excerpts.prev();
3225            }
3226
3227            // Keep any transforms that are before the edit.
3228            if at_transform_boundary {
3229                at_transform_boundary = false;
3230                let transforms_before_edit = old_diff_transforms.slice(&edit.old.start, Bias::Left);
3231                Self::append_diff_transforms(&mut new_diff_transforms, transforms_before_edit);
3232                if let Some(transform) = old_diff_transforms.item()
3233                    && old_diff_transforms.end().0 == edit.old.start
3234                    && old_diff_transforms.start().0 < edit.old.start
3235                {
3236                    Self::push_diff_transform(&mut new_diff_transforms, transform.clone());
3237                    old_diff_transforms.next();
3238                }
3239            }
3240
3241            // Compute the start of the edit in output coordinates.
3242            let edit_start_overshoot = edit.old.start - old_diff_transforms.start().0;
3243            let edit_old_start = old_diff_transforms.start().1 + edit_start_overshoot;
3244            let edit_new_start =
3245                MultiBufferOffset((edit_old_start.0 as isize + output_delta) as usize);
3246
3247            let changed_diff_hunks = Self::recompute_diff_transforms_for_edit(
3248                &edit,
3249                &mut excerpts,
3250                &mut old_diff_transforms,
3251                &mut new_diff_transforms,
3252                &mut end_of_current_insert,
3253                &mut old_expanded_hunks,
3254                snapshot,
3255                change_kind,
3256            );
3257
3258            // Compute the end of the edit in output coordinates.
3259            let edit_old_end_overshoot = edit.old.end - old_diff_transforms.start().0;
3260            let edit_new_end_overshoot = edit.new.end - new_diff_transforms.summary().excerpt_len();
3261            let edit_old_end = old_diff_transforms.start().1 + edit_old_end_overshoot;
3262            let edit_new_end = new_diff_transforms.summary().output.len + edit_new_end_overshoot;
3263            let output_edit = Edit {
3264                old: edit_old_start..edit_old_end,
3265                new: edit_new_start..edit_new_end,
3266            };
3267
3268            output_delta += (output_edit.new.end - output_edit.new.start) as isize;
3269            output_delta -= (output_edit.old.end - output_edit.old.start) as isize;
3270            if changed_diff_hunks || matches!(change_kind, DiffChangeKind::BufferEdited) {
3271                output_edits.push(output_edit);
3272            }
3273
3274            // If this is the last edit that intersects the current diff transform,
3275            // then recreate the content up to the end of this transform, to prepare
3276            // for reusing additional slices of the old transforms.
3277            if excerpt_edits
3278                .peek()
3279                .is_none_or(|next_edit| next_edit.old.start >= old_diff_transforms.end().0)
3280            {
3281                let keep_next_old_transform = (old_diff_transforms.start().0 >= edit.old.end)
3282                    && match old_diff_transforms.item() {
3283                        Some(DiffTransform::BufferContent {
3284                            inserted_hunk_info: Some(hunk),
3285                            ..
3286                        }) => excerpts.item().is_some_and(|excerpt| {
3287                            if let Some(diff) = snapshot.diffs.get(&excerpt.buffer_id)
3288                                && let Some(main_buffer) = &diff.main_buffer
3289                            {
3290                                return hunk.hunk_start_anchor.is_valid(main_buffer);
3291                            }
3292                            hunk.hunk_start_anchor.is_valid(&excerpt.buffer)
3293                        }),
3294                        _ => true,
3295                    };
3296
3297                let mut excerpt_offset = edit.new.end;
3298                if !keep_next_old_transform {
3299                    excerpt_offset += old_diff_transforms.end().0 - edit.old.end;
3300                    old_diff_transforms.next();
3301                }
3302
3303                old_expanded_hunks.clear();
3304                Self::push_buffer_content_transform(
3305                    snapshot,
3306                    &mut new_diff_transforms,
3307                    excerpt_offset,
3308                    end_of_current_insert,
3309                );
3310                at_transform_boundary = true;
3311            }
3312        }
3313
3314        // Keep any transforms that are after the last edit.
3315        Self::append_diff_transforms(&mut new_diff_transforms, old_diff_transforms.suffix());
3316
3317        // Ensure there's always at least one buffer content transform.
3318        if new_diff_transforms.is_empty() {
3319            new_diff_transforms.push(
3320                DiffTransform::BufferContent {
3321                    summary: Default::default(),
3322                    inserted_hunk_info: None,
3323                },
3324                (),
3325            );
3326        }
3327
3328        drop(old_diff_transforms);
3329        drop(excerpts);
3330        snapshot.diff_transforms = new_diff_transforms;
3331        snapshot.edit_count += 1;
3332
3333        #[cfg(any(test, feature = "test-support"))]
3334        snapshot.check_invariants();
3335        output_edits
3336    }
3337
3338    fn recompute_diff_transforms_for_edit(
3339        edit: &Edit<ExcerptOffset>,
3340        excerpts: &mut Cursor<Excerpt, ExcerptOffset>,
3341        old_diff_transforms: &mut Cursor<
3342            DiffTransform,
3343            Dimensions<ExcerptOffset, MultiBufferOffset>,
3344        >,
3345        new_diff_transforms: &mut SumTree<DiffTransform>,
3346        end_of_current_insert: &mut Option<(ExcerptOffset, DiffTransformHunkInfo)>,
3347        old_expanded_hunks: &mut HashSet<DiffTransformHunkInfo>,
3348        snapshot: &MultiBufferSnapshot,
3349        change_kind: DiffChangeKind,
3350    ) -> bool {
3351        log::trace!(
3352            "recomputing diff transform for edit {:?} => {:?}",
3353            edit.old.start..edit.old.end,
3354            edit.new.start..edit.new.end
3355        );
3356
3357        // Record which hunks were previously expanded.
3358        while let Some(item) = old_diff_transforms.item() {
3359            if let Some(hunk_info) = item.hunk_info() {
3360                log::trace!(
3361                    "previously expanded hunk at {:?}",
3362                    old_diff_transforms.start()
3363                );
3364                old_expanded_hunks.insert(hunk_info);
3365            }
3366            if old_diff_transforms.end().0 > edit.old.end {
3367                break;
3368            }
3369            old_diff_transforms.next();
3370        }
3371
3372        // Avoid querying diff hunks if there's no possibility of hunks being expanded.
3373        // For inverted diffs, hunks are always shown, so we can't skip this.
3374        let all_diff_hunks_expanded = snapshot.all_diff_hunks_expanded;
3375        if old_expanded_hunks.is_empty()
3376            && change_kind == DiffChangeKind::BufferEdited
3377            && !all_diff_hunks_expanded
3378            && !snapshot.has_inverted_diff
3379        {
3380            return false;
3381        }
3382
3383        // Visit each excerpt that intersects the edit.
3384        let mut did_expand_hunks = false;
3385        while let Some(excerpt) = excerpts.item() {
3386            // Recompute the expanded hunks in the portion of the excerpt that
3387            // intersects the edit.
3388            if let Some(diff) = snapshot.diffs.get(&excerpt.buffer_id) {
3389                let buffer = &excerpt.buffer;
3390                let excerpt_start = *excerpts.start();
3391                let excerpt_end = excerpt_start + excerpt.text_summary.len;
3392                let excerpt_buffer_start = excerpt.range.context.start.to_offset(buffer);
3393                let excerpt_buffer_end = excerpt_buffer_start + excerpt.text_summary.len;
3394                let edit_buffer_start =
3395                    excerpt_buffer_start + edit.new.start.saturating_sub(excerpt_start);
3396                let edit_buffer_end =
3397                    excerpt_buffer_start + edit.new.end.saturating_sub(excerpt_start);
3398                let edit_buffer_end = edit_buffer_end.min(excerpt_buffer_end);
3399
3400                if let Some(main_buffer) = &diff.main_buffer {
3401                    for hunk in diff.hunks_intersecting_base_text_range(
3402                        edit_buffer_start..edit_buffer_end,
3403                        main_buffer,
3404                    ) {
3405                        let hunk_buffer_range = hunk.diff_base_byte_range.clone();
3406                        if hunk_buffer_range.start < excerpt_buffer_start {
3407                            log::trace!("skipping hunk that starts before excerpt");
3408                            continue;
3409                        }
3410                        hunk_buffer_range.end.to_point(&excerpt.buffer);
3411                        let hunk_excerpt_start = excerpt_start
3412                            + hunk_buffer_range.start.saturating_sub(excerpt_buffer_start);
3413                        let hunk_excerpt_end = excerpt_end
3414                            .min(excerpt_start + (hunk_buffer_range.end - excerpt_buffer_start));
3415                        Self::push_buffer_content_transform(
3416                            snapshot,
3417                            new_diff_transforms,
3418                            hunk_excerpt_start,
3419                            *end_of_current_insert,
3420                        );
3421                        if !hunk_buffer_range.is_empty() {
3422                            let hunk_info = DiffTransformHunkInfo {
3423                                excerpt_id: excerpt.id,
3424                                hunk_start_anchor: hunk.buffer_range.start,
3425                                hunk_secondary_status: hunk.secondary_status,
3426                                is_logically_deleted: true,
3427                            };
3428                            *end_of_current_insert =
3429                                Some((hunk_excerpt_end.min(excerpt_end), hunk_info));
3430                        }
3431                    }
3432                } else {
3433                    let edit_anchor_range = buffer.anchor_before(edit_buffer_start)
3434                        ..buffer.anchor_after(edit_buffer_end);
3435                    for hunk in diff.hunks_intersecting_range(edit_anchor_range, buffer) {
3436                        if hunk.is_created_file() && !all_diff_hunks_expanded {
3437                            continue;
3438                        }
3439
3440                        let hunk_buffer_range = hunk.buffer_range.to_offset(buffer);
3441                        if hunk_buffer_range.start < excerpt_buffer_start {
3442                            log::trace!("skipping hunk that starts before excerpt");
3443                            continue;
3444                        }
3445
3446                        let hunk_info = DiffTransformHunkInfo {
3447                            excerpt_id: excerpt.id,
3448                            hunk_start_anchor: hunk.buffer_range.start,
3449                            hunk_secondary_status: hunk.secondary_status,
3450                            is_logically_deleted: false,
3451                        };
3452
3453                        let hunk_excerpt_start = excerpt_start
3454                            + hunk_buffer_range.start.saturating_sub(excerpt_buffer_start);
3455                        let hunk_excerpt_end = excerpt_end
3456                            .min(excerpt_start + (hunk_buffer_range.end - excerpt_buffer_start));
3457
3458                        Self::push_buffer_content_transform(
3459                            snapshot,
3460                            new_diff_transforms,
3461                            hunk_excerpt_start,
3462                            *end_of_current_insert,
3463                        );
3464
3465                        // For every existing hunk, determine if it was previously expanded
3466                        // and if it should currently be expanded.
3467                        let was_previously_expanded = old_expanded_hunks.contains(&hunk_info);
3468                        let should_expand_hunk = match &change_kind {
3469                            DiffChangeKind::DiffUpdated { base_changed: true } => {
3470                                was_previously_expanded || all_diff_hunks_expanded
3471                            }
3472                            DiffChangeKind::ExpandOrCollapseHunks { expand } => {
3473                                let intersects = hunk_buffer_range.is_empty()
3474                                    || hunk_buffer_range.end > edit_buffer_start;
3475                                if *expand {
3476                                    intersects || was_previously_expanded || all_diff_hunks_expanded
3477                                } else {
3478                                    !intersects
3479                                        && (was_previously_expanded || all_diff_hunks_expanded)
3480                                }
3481                            }
3482                            _ => was_previously_expanded || all_diff_hunks_expanded,
3483                        };
3484
3485                        if should_expand_hunk {
3486                            did_expand_hunks = true;
3487                            log::trace!(
3488                                "expanding hunk {:?}, excerpt:{:?}",
3489                                hunk_excerpt_start..hunk_excerpt_end,
3490                                excerpt.id
3491                            );
3492
3493                            if !hunk.diff_base_byte_range.is_empty()
3494                                && hunk_buffer_range.start >= edit_buffer_start
3495                                && hunk_buffer_range.start <= excerpt_buffer_end
3496                                && snapshot.show_deleted_hunks
3497                            {
3498                                let base_text = diff.base_text();
3499                                let mut text_cursor =
3500                                    base_text.as_rope().cursor(hunk.diff_base_byte_range.start);
3501                                let mut base_text_summary = text_cursor
3502                                    .summary::<TextSummary>(hunk.diff_base_byte_range.end);
3503
3504                                let mut has_trailing_newline = false;
3505                                if base_text_summary.last_line_chars > 0 {
3506                                    base_text_summary += TextSummary::newline();
3507                                    has_trailing_newline = true;
3508                                }
3509
3510                                new_diff_transforms.push(
3511                                    DiffTransform::DeletedHunk {
3512                                        base_text_byte_range: hunk.diff_base_byte_range.clone(),
3513                                        summary: base_text_summary,
3514                                        buffer_id: excerpt.buffer_id,
3515                                        hunk_info,
3516                                        has_trailing_newline,
3517                                    },
3518                                    (),
3519                                );
3520                            }
3521
3522                            if !hunk_buffer_range.is_empty() {
3523                                *end_of_current_insert =
3524                                    Some((hunk_excerpt_end.min(excerpt_end), hunk_info));
3525                            }
3526                        }
3527                    }
3528                }
3529            }
3530
3531            if excerpts.end() <= edit.new.end {
3532                excerpts.next();
3533            } else {
3534                break;
3535            }
3536        }
3537
3538        did_expand_hunks || !old_expanded_hunks.is_empty()
3539    }
3540
3541    fn append_diff_transforms(
3542        new_transforms: &mut SumTree<DiffTransform>,
3543        subtree: SumTree<DiffTransform>,
3544    ) {
3545        if let Some(DiffTransform::BufferContent {
3546            inserted_hunk_info,
3547            summary,
3548        }) = subtree.first()
3549            && Self::extend_last_buffer_content_transform(
3550                new_transforms,
3551                *inserted_hunk_info,
3552                *summary,
3553            )
3554        {
3555            let mut cursor = subtree.cursor::<()>(());
3556            cursor.next();
3557            cursor.next();
3558            new_transforms.append(cursor.suffix(), ());
3559            return;
3560        }
3561        new_transforms.append(subtree, ());
3562    }
3563
3564    fn push_diff_transform(new_transforms: &mut SumTree<DiffTransform>, transform: DiffTransform) {
3565        if let DiffTransform::BufferContent {
3566            inserted_hunk_info: inserted_hunk_anchor,
3567            summary,
3568        } = transform
3569            && Self::extend_last_buffer_content_transform(
3570                new_transforms,
3571                inserted_hunk_anchor,
3572                summary,
3573            )
3574        {
3575            return;
3576        }
3577        new_transforms.push(transform, ());
3578    }
3579
3580    fn push_buffer_content_transform(
3581        old_snapshot: &MultiBufferSnapshot,
3582        new_transforms: &mut SumTree<DiffTransform>,
3583        end_offset: ExcerptOffset,
3584        current_inserted_hunk: Option<(ExcerptOffset, DiffTransformHunkInfo)>,
3585    ) {
3586        let inserted_region = current_inserted_hunk.map(|(insertion_end_offset, hunk_info)| {
3587            (end_offset.min(insertion_end_offset), Some(hunk_info))
3588        });
3589        let unchanged_region = [(end_offset, None)];
3590
3591        for (end_offset, inserted_hunk_info) in inserted_region.into_iter().chain(unchanged_region)
3592        {
3593            let start_offset = new_transforms.summary().excerpt_len();
3594            if end_offset <= start_offset {
3595                continue;
3596            }
3597            let summary_to_add = old_snapshot
3598                .text_summary_for_excerpt_offset_range::<MBTextSummary>(start_offset..end_offset);
3599
3600            if !Self::extend_last_buffer_content_transform(
3601                new_transforms,
3602                inserted_hunk_info,
3603                summary_to_add,
3604            ) {
3605                new_transforms.push(
3606                    DiffTransform::BufferContent {
3607                        summary: summary_to_add,
3608                        inserted_hunk_info,
3609                    },
3610                    (),
3611                )
3612            }
3613        }
3614    }
3615
3616    fn extend_last_buffer_content_transform(
3617        new_transforms: &mut SumTree<DiffTransform>,
3618        new_inserted_hunk_info: Option<DiffTransformHunkInfo>,
3619        summary_to_add: MBTextSummary,
3620    ) -> bool {
3621        let mut did_extend = false;
3622        new_transforms.update_last(
3623            |last_transform| {
3624                if let DiffTransform::BufferContent {
3625                    summary,
3626                    inserted_hunk_info: inserted_hunk_anchor,
3627                } = last_transform
3628                    && *inserted_hunk_anchor == new_inserted_hunk_info
3629                {
3630                    *summary += summary_to_add;
3631                    did_extend = true;
3632                }
3633            },
3634            (),
3635        );
3636        did_extend
3637    }
3638}
3639
3640fn build_excerpt_ranges(
3641    ranges: impl IntoIterator<Item = Range<Point>>,
3642    context_line_count: u32,
3643    buffer_snapshot: &BufferSnapshot,
3644) -> Vec<ExcerptRange<Point>> {
3645    ranges
3646        .into_iter()
3647        .map(|range| {
3648            let start_row = range.start.row.saturating_sub(context_line_count);
3649            let start = Point::new(start_row, 0);
3650            let end_row = (range.end.row + context_line_count).min(buffer_snapshot.max_point().row);
3651            let end = Point::new(end_row, buffer_snapshot.line_len(end_row));
3652            ExcerptRange {
3653                context: start..end,
3654                primary: range,
3655            }
3656        })
3657        .collect()
3658}
3659
3660#[cfg(any(test, feature = "test-support"))]
3661impl MultiBuffer {
3662    pub fn build_simple(text: &str, cx: &mut gpui::App) -> Entity<Self> {
3663        let buffer = cx.new(|cx| Buffer::local(text, cx));
3664        cx.new(|cx| Self::singleton(buffer, cx))
3665    }
3666
3667    pub fn build_multi<const COUNT: usize>(
3668        excerpts: [(&str, Vec<Range<Point>>); COUNT],
3669        cx: &mut gpui::App,
3670    ) -> Entity<Self> {
3671        let multi = cx.new(|_| Self::new(Capability::ReadWrite));
3672        for (text, ranges) in excerpts {
3673            let buffer = cx.new(|cx| Buffer::local(text, cx));
3674            let excerpt_ranges = ranges.into_iter().map(ExcerptRange::new);
3675            multi.update(cx, |multi, cx| {
3676                multi.push_excerpts(buffer, excerpt_ranges, cx)
3677            });
3678        }
3679
3680        multi
3681    }
3682
3683    pub fn build_from_buffer(buffer: Entity<Buffer>, cx: &mut gpui::App) -> Entity<Self> {
3684        cx.new(|cx| Self::singleton(buffer, cx))
3685    }
3686
3687    pub fn build_random(rng: &mut impl rand::Rng, cx: &mut gpui::App) -> Entity<Self> {
3688        cx.new(|cx| {
3689            let mut multibuffer = MultiBuffer::new(Capability::ReadWrite);
3690            let mutation_count = rng.random_range(1..=5);
3691            multibuffer.randomly_edit_excerpts(rng, mutation_count, cx);
3692            multibuffer
3693        })
3694    }
3695
3696    pub fn randomly_edit(
3697        &mut self,
3698        rng: &mut impl rand::Rng,
3699        edit_count: usize,
3700        cx: &mut Context<Self>,
3701    ) {
3702        use util::RandomCharIter;
3703
3704        let snapshot = self.read(cx);
3705        let mut edits: Vec<(Range<MultiBufferOffset>, Arc<str>)> = Vec::new();
3706        let mut last_end = None;
3707        for _ in 0..edit_count {
3708            if last_end.is_some_and(|last_end| last_end >= snapshot.len()) {
3709                break;
3710            }
3711
3712            let new_start = last_end.map_or(MultiBufferOffset::ZERO, |last_end| last_end + 1usize);
3713            let end =
3714                snapshot.clip_offset(rng.random_range(new_start..=snapshot.len()), Bias::Right);
3715            let start = snapshot.clip_offset(rng.random_range(new_start..=end), Bias::Right);
3716            last_end = Some(end);
3717
3718            let mut range = start..end;
3719            if rng.random_bool(0.2) {
3720                mem::swap(&mut range.start, &mut range.end);
3721            }
3722
3723            let new_text_len = rng.random_range(0..10);
3724            let new_text: String = RandomCharIter::new(&mut *rng).take(new_text_len).collect();
3725
3726            edits.push((range, new_text.into()));
3727        }
3728        log::info!("mutating multi-buffer with {:?}", edits);
3729        drop(snapshot);
3730
3731        self.edit(edits, None, cx);
3732    }
3733
3734    pub fn randomly_edit_excerpts(
3735        &mut self,
3736        rng: &mut impl rand::Rng,
3737        mutation_count: usize,
3738        cx: &mut Context<Self>,
3739    ) {
3740        use rand::prelude::*;
3741        use std::env;
3742        use util::RandomCharIter;
3743
3744        let max_excerpts = env::var("MAX_EXCERPTS")
3745            .map(|i| i.parse().expect("invalid `MAX_EXCERPTS` variable"))
3746            .unwrap_or(5);
3747
3748        let mut buffers = Vec::new();
3749        for _ in 0..mutation_count {
3750            if rng.random_bool(0.05) {
3751                log::info!("Clearing multi-buffer");
3752                self.clear(cx);
3753                continue;
3754            } else if rng.random_bool(0.1) && !self.excerpt_ids().is_empty() {
3755                let ids = self.excerpt_ids();
3756                let mut excerpts = HashSet::default();
3757                for _ in 0..rng.random_range(0..ids.len()) {
3758                    excerpts.extend(ids.choose(rng).copied());
3759                }
3760
3761                let line_count = rng.random_range(0..5);
3762
3763                log::info!("Expanding excerpts {excerpts:?} by {line_count} lines");
3764
3765                self.expand_excerpts(
3766                    excerpts.iter().cloned(),
3767                    line_count,
3768                    ExpandExcerptDirection::UpAndDown,
3769                    cx,
3770                );
3771                continue;
3772            }
3773
3774            let excerpt_ids = self.excerpt_ids();
3775            if excerpt_ids.is_empty() || (rng.random() && excerpt_ids.len() < max_excerpts) {
3776                let buffer_handle = if rng.random() || self.buffers.is_empty() {
3777                    let text = RandomCharIter::new(&mut *rng).take(10).collect::<String>();
3778                    buffers.push(cx.new(|cx| Buffer::local(text, cx)));
3779                    let buffer = buffers.last().unwrap().read(cx);
3780                    log::info!(
3781                        "Creating new buffer {} with text: {:?}",
3782                        buffer.remote_id(),
3783                        buffer.text()
3784                    );
3785                    buffers.last().unwrap().clone()
3786                } else {
3787                    self.buffers.values().choose(rng).unwrap().buffer.clone()
3788                };
3789
3790                let buffer = buffer_handle.read(cx);
3791                let buffer_text = buffer.text();
3792                let ranges = (0..rng.random_range(0..5))
3793                    .map(|_| {
3794                        let end_ix =
3795                            buffer.clip_offset(rng.random_range(0..=buffer.len()), Bias::Right);
3796                        let start_ix = buffer.clip_offset(rng.random_range(0..=end_ix), Bias::Left);
3797                        ExcerptRange::new(start_ix..end_ix)
3798                    })
3799                    .collect::<Vec<_>>();
3800                log::info!(
3801                    "Inserting excerpts from buffer {} and ranges {:?}: {:?}",
3802                    buffer_handle.read(cx).remote_id(),
3803                    ranges.iter().map(|r| &r.context).collect::<Vec<_>>(),
3804                    ranges
3805                        .iter()
3806                        .map(|r| &buffer_text[r.context.clone()])
3807                        .collect::<Vec<_>>()
3808                );
3809
3810                let excerpt_id = self.push_excerpts(buffer_handle.clone(), ranges, cx);
3811                log::info!("Inserted with ids: {:?}", excerpt_id);
3812            } else {
3813                let remove_count = rng.random_range(1..=excerpt_ids.len());
3814                let mut excerpts_to_remove = excerpt_ids
3815                    .choose_multiple(rng, remove_count)
3816                    .cloned()
3817                    .collect::<Vec<_>>();
3818                let snapshot = self.snapshot.borrow();
3819                excerpts_to_remove.sort_unstable_by(|a, b| a.cmp(b, &snapshot));
3820                drop(snapshot);
3821                log::info!("Removing excerpts {:?}", excerpts_to_remove);
3822                self.remove_excerpts(excerpts_to_remove, cx);
3823            }
3824        }
3825    }
3826
3827    pub fn randomly_mutate(
3828        &mut self,
3829        rng: &mut impl rand::Rng,
3830        mutation_count: usize,
3831        cx: &mut Context<Self>,
3832    ) {
3833        use rand::prelude::*;
3834
3835        if rng.random_bool(0.7) || self.singleton {
3836            let buffer = self
3837                .buffers
3838                .values()
3839                .choose(rng)
3840                .map(|state| state.buffer.clone());
3841
3842            if let Some(buffer) = buffer {
3843                buffer.update(cx, |buffer, cx| {
3844                    if rng.random() {
3845                        buffer.randomly_edit(rng, mutation_count, cx);
3846                    } else {
3847                        buffer.randomly_undo_redo(rng, cx);
3848                    }
3849                });
3850            } else {
3851                self.randomly_edit(rng, mutation_count, cx);
3852            }
3853        } else {
3854            self.randomly_edit_excerpts(rng, mutation_count, cx);
3855        }
3856
3857        self.check_invariants(cx);
3858    }
3859
3860    fn check_invariants(&self, cx: &App) {
3861        self.read(cx).check_invariants();
3862    }
3863}
3864
3865impl EventEmitter<Event> for MultiBuffer {}
3866
3867impl MultiBufferSnapshot {
3868    pub fn text(&self) -> String {
3869        self.chunks(MultiBufferOffset::ZERO..self.len(), false)
3870            .map(|chunk| chunk.text)
3871            .collect()
3872    }
3873
3874    pub fn reversed_chars_at<T: ToOffset>(&self, position: T) -> impl Iterator<Item = char> + '_ {
3875        self.reversed_chunks_in_range(MultiBufferOffset::ZERO..position.to_offset(self))
3876            .flat_map(|c| c.chars().rev())
3877    }
3878
3879    fn reversed_chunks_in_range(
3880        &self,
3881        range: Range<MultiBufferOffset>,
3882    ) -> ReversedMultiBufferChunks<'_> {
3883        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
3884        cursor.seek(&range.end);
3885        let current_chunks = cursor.region().as_ref().map(|region| {
3886            let start_overshoot = range.start.saturating_sub(region.range.start);
3887            let end_overshoot = range.end - region.range.start;
3888            let end = (region.buffer_range.start + end_overshoot).min(region.buffer_range.end);
3889            let start = region.buffer_range.start + start_overshoot;
3890            region.buffer.reversed_chunks_in_range(start..end)
3891        });
3892        ReversedMultiBufferChunks {
3893            cursor,
3894            current_chunks,
3895            start: range.start,
3896            offset: range.end,
3897        }
3898    }
3899
3900    pub fn chars_at<T: ToOffset>(&self, position: T) -> impl Iterator<Item = char> + '_ {
3901        let offset = position.to_offset(self);
3902        self.text_for_range(offset..self.len())
3903            .flat_map(|chunk| chunk.chars())
3904    }
3905
3906    pub fn text_for_range<T: ToOffset>(&self, range: Range<T>) -> impl Iterator<Item = &str> + '_ {
3907        self.chunks(range, false).map(|chunk| chunk.text)
3908    }
3909
3910    pub fn is_line_blank(&self, row: MultiBufferRow) -> bool {
3911        self.text_for_range(Point::new(row.0, 0)..Point::new(row.0, self.line_len(row)))
3912            .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
3913    }
3914
3915    pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
3916    where
3917        T: ToOffset,
3918    {
3919        let position = position.to_offset(self);
3920        position == self.clip_offset(position, Bias::Left)
3921            && self
3922                .bytes_in_range(position..self.len())
3923                .flatten()
3924                .copied()
3925                .take(needle.len())
3926                .eq(needle.bytes())
3927    }
3928
3929    pub fn diff_hunks(&self) -> impl Iterator<Item = MultiBufferDiffHunk> + '_ {
3930        self.diff_hunks_in_range(Anchor::min()..Anchor::max())
3931    }
3932
3933    pub fn diff_hunks_in_range<T: ToPoint>(
3934        &self,
3935        range: Range<T>,
3936    ) -> impl Iterator<Item = MultiBufferDiffHunk> + '_ {
3937        let query_range = range.start.to_point(self)..range.end.to_point(self);
3938        self.lift_buffer_metadata(query_range.clone(), move |buffer, buffer_range| {
3939            let diff = self.diffs.get(&buffer.remote_id())?;
3940            let iter: Box<dyn Iterator<Item = (DiffHunk, &BufferSnapshot, bool)>> =
3941                if let Some(main_buffer) = &diff.main_buffer {
3942                    let buffer_start = buffer.point_to_offset(buffer_range.start);
3943                    let buffer_end = buffer.point_to_offset(buffer_range.end);
3944                    Box::new(
3945                        diff.hunks_intersecting_base_text_range(
3946                            buffer_start..buffer_end,
3947                            main_buffer,
3948                        )
3949                        .map(move |hunk| (hunk, buffer, true)),
3950                    )
3951                } else {
3952                    let buffer_start = buffer.anchor_before(buffer_range.start);
3953                    let buffer_end = buffer.anchor_after(buffer_range.end);
3954                    Box::new(
3955                        diff.hunks_intersecting_range(buffer_start..buffer_end, buffer)
3956                            .map(move |hunk| (hunk, buffer, false)),
3957                    )
3958                };
3959            Some(iter.filter_map(|(hunk, buffer, is_inverted)| {
3960                if hunk.is_created_file() && !self.all_diff_hunks_expanded {
3961                    return None;
3962                }
3963                let range = if is_inverted {
3964                    hunk.diff_base_byte_range.to_point(&buffer)
3965                } else {
3966                    hunk.range.clone()
3967                };
3968                Some((range, (hunk, is_inverted)))
3969            }))
3970        })
3971        .filter_map(move |(range, (hunk, is_inverted), excerpt)| {
3972            if range.start != range.end && range.end == query_range.start && !hunk.range.is_empty()
3973            {
3974                return None;
3975            }
3976            let end_row = if range.end.column == 0 {
3977                range.end.row
3978            } else {
3979                range.end.row + 1
3980            };
3981
3982            let word_diffs =
3983                (!hunk.base_word_diffs.is_empty() || !hunk.buffer_word_diffs.is_empty())
3984                    .then(|| {
3985                        let mut word_diffs = Vec::new();
3986
3987                        if self.show_deleted_hunks || is_inverted {
3988                            let hunk_start_offset = if is_inverted {
3989                                Anchor::in_buffer(
3990                                    excerpt.id,
3991                                    excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start),
3992                                )
3993                                .to_offset(self)
3994                            } else {
3995                                Anchor::in_buffer(excerpt.id, hunk.buffer_range.start)
3996                                    .to_offset(self)
3997                            };
3998
3999                            word_diffs.extend(hunk.base_word_diffs.iter().map(|diff| {
4000                                hunk_start_offset + diff.start..hunk_start_offset + diff.end
4001                            }));
4002                        }
4003
4004                        if !is_inverted {
4005                            word_diffs.extend(hunk.buffer_word_diffs.into_iter().map(|diff| {
4006                                Anchor::range_in_buffer(excerpt.id, diff).to_offset(self)
4007                            }));
4008                        }
4009                        word_diffs
4010                    })
4011                    .unwrap_or_default();
4012
4013            let buffer_range = if is_inverted {
4014                excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start)
4015                    ..excerpt.buffer.anchor_before(hunk.diff_base_byte_range.end)
4016            } else {
4017                hunk.buffer_range.clone()
4018            };
4019            let status_kind = if hunk.buffer_range.start == hunk.buffer_range.end {
4020                DiffHunkStatusKind::Deleted
4021            } else if hunk.diff_base_byte_range.is_empty() {
4022                DiffHunkStatusKind::Added
4023            } else {
4024                DiffHunkStatusKind::Modified
4025            };
4026            Some(MultiBufferDiffHunk {
4027                row_range: MultiBufferRow(range.start.row)..MultiBufferRow(end_row),
4028                buffer_id: excerpt.buffer_id,
4029                excerpt_id: excerpt.id,
4030                buffer_range,
4031                word_diffs,
4032                diff_base_byte_range: BufferOffset(hunk.diff_base_byte_range.start)
4033                    ..BufferOffset(hunk.diff_base_byte_range.end),
4034                status: DiffHunkStatus {
4035                    kind: status_kind,
4036                    secondary: hunk.secondary_status,
4037                },
4038            })
4039        })
4040    }
4041
4042    fn excerpts_for_range<T: ToOffset>(
4043        &self,
4044        range: Range<T>,
4045    ) -> impl Iterator<Item = &Excerpt> + '_ {
4046        let range = range.start.to_offset(self)..range.end.to_offset(self);
4047        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
4048        cursor.seek(&range.start);
4049        std::iter::from_fn(move || {
4050            let region = cursor.region()?;
4051            if region.range.start > range.end
4052                || region.range.start == range.end && region.range.start > range.start
4053            {
4054                return None;
4055            }
4056            cursor.next_excerpt();
4057            Some(region.excerpt)
4058        })
4059    }
4060
4061    pub fn excerpt_ids_for_range<T: ToOffset>(
4062        &self,
4063        range: Range<T>,
4064    ) -> impl Iterator<Item = ExcerptId> + '_ {
4065        self.excerpts_for_range(range).map(|excerpt| excerpt.id)
4066    }
4067
4068    pub fn buffer_ids_for_range<T: ToOffset>(
4069        &self,
4070        range: Range<T>,
4071    ) -> impl Iterator<Item = BufferId> + '_ {
4072        self.excerpts_for_range(range)
4073            .map(|excerpt| excerpt.buffer_id)
4074    }
4075
4076    pub fn ranges_to_buffer_ranges<T: ToOffset>(
4077        &self,
4078        ranges: impl Iterator<Item = Range<T>>,
4079    ) -> impl Iterator<Item = (&BufferSnapshot, Range<BufferOffset>, ExcerptId)> {
4080        ranges.flat_map(|range| self.range_to_buffer_ranges(range).into_iter())
4081    }
4082
4083    pub fn range_to_buffer_ranges<T: ToOffset>(
4084        &self,
4085        range: Range<T>,
4086    ) -> Vec<(&BufferSnapshot, Range<BufferOffset>, ExcerptId)> {
4087        let start = range.start.to_offset(self);
4088        let end = range.end.to_offset(self);
4089
4090        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
4091        cursor.seek(&start);
4092
4093        let mut result: Vec<(&BufferSnapshot, Range<BufferOffset>, ExcerptId)> = Vec::new();
4094        while let Some(region) = cursor.region() {
4095            if region.range.start > end {
4096                break;
4097            }
4098            if region.is_main_buffer {
4099                let start_overshoot = start.saturating_sub(region.range.start);
4100                let end_overshoot = end.saturating_sub(region.range.start);
4101                let start = region
4102                    .buffer_range
4103                    .end
4104                    .min(region.buffer_range.start + start_overshoot);
4105                let end = region
4106                    .buffer_range
4107                    .end
4108                    .min(region.buffer_range.start + end_overshoot);
4109                if let Some(prev) = result.last_mut().filter(|(_, prev_range, excerpt_id)| {
4110                    *excerpt_id == region.excerpt.id && prev_range.end == start
4111                }) {
4112                    prev.1.end = end;
4113                } else {
4114                    result.push((region.buffer, start..end, region.excerpt.id));
4115                }
4116            }
4117            cursor.next();
4118        }
4119        result
4120    }
4121
4122    pub fn range_to_buffer_ranges_with_deleted_hunks<T: ToOffset>(
4123        &self,
4124        range: Range<T>,
4125    ) -> impl Iterator<
4126        Item = (
4127            &BufferSnapshot,
4128            Range<BufferOffset>,
4129            ExcerptId,
4130            Option<Anchor>,
4131        ),
4132    > + '_ {
4133        let start = range.start.to_offset(self);
4134        let end = range.end.to_offset(self);
4135
4136        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
4137        cursor.seek(&start);
4138
4139        std::iter::from_fn(move || {
4140            let region = cursor.region()?;
4141            if region.range.start > end {
4142                return None;
4143            }
4144            let start_overshoot = start.saturating_sub(region.range.start);
4145            let end_overshoot = end.saturating_sub(region.range.start);
4146            let start = region
4147                .buffer_range
4148                .end
4149                .min(region.buffer_range.start + start_overshoot);
4150            let end = region
4151                .buffer_range
4152                .end
4153                .min(region.buffer_range.start + end_overshoot);
4154
4155            let region_excerpt_id = region.excerpt.id;
4156            let deleted_hunk_anchor = if region.is_main_buffer {
4157                None
4158            } else {
4159                Some(self.anchor_before(region.range.start))
4160            };
4161            let result = (
4162                region.buffer,
4163                start..end,
4164                region_excerpt_id,
4165                deleted_hunk_anchor,
4166            );
4167            cursor.next();
4168            Some(result)
4169        })
4170    }
4171
4172    /// Retrieves buffer metadata for the given range, and converts it into multi-buffer
4173    /// coordinates.
4174    ///
4175    /// The given callback will be called for every excerpt intersecting the given range. It will
4176    /// be passed the excerpt's buffer and the buffer range that the input range intersects.
4177    /// The callback should return an iterator of metadata items from that buffer, each paired
4178    /// with a buffer range.
4179    ///
4180    /// The returned iterator yields each of these metadata items, paired with its range in
4181    /// multi-buffer coordinates.
4182    fn lift_buffer_metadata<'a, MBD, M, I>(
4183        &'a self,
4184        query_range: Range<MBD>,
4185        get_buffer_metadata: impl 'a + Fn(&'a BufferSnapshot, Range<MBD::TextDimension>) -> Option<I>,
4186    ) -> impl Iterator<Item = (Range<MBD>, M, &'a Excerpt)> + 'a
4187    where
4188        I: Iterator<Item = (Range<MBD::TextDimension>, M)> + 'a,
4189        MBD: MultiBufferDimension
4190            + Ord
4191            + Sub<Output = MBD::TextDimension>
4192            + ops::Add<MBD::TextDimension, Output = MBD>
4193            + ops::AddAssign<MBD::TextDimension>,
4194        MBD::TextDimension: Sub<Output = MBD::TextDimension>
4195            + ops::Add<Output = MBD::TextDimension>
4196            + AddAssign<MBD::TextDimension>
4197            + Ord,
4198    {
4199        let mut current_excerpt_metadata: Option<(ExcerptId, I)> = None;
4200        let mut cursor = self.cursor::<MBD, MBD::TextDimension>();
4201
4202        // Find the excerpt and buffer offset where the given range ends.
4203        cursor.seek(&query_range.end);
4204        let mut range_end = None;
4205        while let Some(region) = cursor.region() {
4206            if region.is_main_buffer {
4207                let mut buffer_end = region.buffer_range.start;
4208                let overshoot = if query_range.end > region.range.start {
4209                    query_range.end - region.range.start
4210                } else {
4211                    <MBD::TextDimension>::default()
4212                };
4213                buffer_end = buffer_end + overshoot;
4214                range_end = Some((region.excerpt.id, buffer_end));
4215                break;
4216            }
4217            cursor.next();
4218        }
4219
4220        cursor.seek(&query_range.start);
4221
4222        if let Some(region) = cursor.region().filter(|region| !region.is_main_buffer)
4223            && region.range.start > MBD::default()
4224        {
4225            cursor.prev()
4226        }
4227
4228        iter::from_fn(move || {
4229            loop {
4230                let excerpt = cursor.excerpt()?;
4231
4232                // If we have already retrieved metadata for this excerpt, continue to use it.
4233                let metadata_iter = if let Some((_, metadata)) = current_excerpt_metadata
4234                    .as_mut()
4235                    .filter(|(excerpt_id, _)| *excerpt_id == excerpt.id)
4236                {
4237                    Some(metadata)
4238                }
4239                // Otherwise, compute the intersection of the input range with the excerpt's range,
4240                // and retrieve the metadata for the resulting range.
4241                else {
4242                    let region = cursor.region()?;
4243                    let mut buffer_start;
4244                    if region.is_main_buffer {
4245                        buffer_start = region.buffer_range.start;
4246                        if query_range.start > region.range.start {
4247                            let overshoot = query_range.start - region.range.start;
4248                            buffer_start = buffer_start + overshoot;
4249                        }
4250                        buffer_start = buffer_start.min(region.buffer_range.end);
4251                    } else {
4252                        buffer_start = cursor.main_buffer_position()?;
4253                    };
4254                    let mut buffer_end = excerpt
4255                        .range
4256                        .context
4257                        .end
4258                        .summary::<MBD::TextDimension>(&excerpt.buffer);
4259                    if let Some((end_excerpt_id, end_buffer_offset)) = range_end
4260                        && excerpt.id == end_excerpt_id
4261                    {
4262                        buffer_end = buffer_end.min(end_buffer_offset);
4263                    }
4264
4265                    get_buffer_metadata(&excerpt.buffer, buffer_start..buffer_end).map(|iterator| {
4266                        &mut current_excerpt_metadata.insert((excerpt.id, iterator)).1
4267                    })
4268                };
4269
4270                // Visit each metadata item.
4271                if let Some((metadata_buffer_range, metadata)) =
4272                    metadata_iter.and_then(Iterator::next)
4273                {
4274                    // Find the multibuffer regions that contain the start and end of
4275                    // the metadata item's range.
4276                    if metadata_buffer_range.start > <MBD::TextDimension>::default() {
4277                        while let Some(region) = cursor.region() {
4278                            if region.is_main_buffer
4279                                && (region.buffer_range.end >= metadata_buffer_range.start
4280                                    || cursor.is_at_end_of_excerpt())
4281                            {
4282                                break;
4283                            }
4284                            cursor.next();
4285                        }
4286                    }
4287                    let start_region = cursor.region()?;
4288                    while let Some(region) = cursor.region() {
4289                        if region.is_main_buffer
4290                            && (region.buffer_range.end > metadata_buffer_range.end
4291                                || cursor.is_at_end_of_excerpt())
4292                        {
4293                            break;
4294                        }
4295                        cursor.next();
4296                    }
4297                    let end_region = cursor.region();
4298
4299                    // Convert the metadata item's range into multibuffer coordinates.
4300                    let mut start_position = start_region.range.start;
4301                    let region_buffer_start = start_region.buffer_range.start;
4302                    if start_region.is_main_buffer
4303                        && metadata_buffer_range.start > region_buffer_start
4304                    {
4305                        start_position =
4306                            start_position + (metadata_buffer_range.start - region_buffer_start);
4307                        start_position = start_position.min(start_region.range.end);
4308                    }
4309
4310                    let mut end_position = self.max_position();
4311                    if let Some(end_region) = &end_region {
4312                        end_position = end_region.range.start;
4313                        debug_assert!(end_region.is_main_buffer);
4314                        let region_buffer_start = end_region.buffer_range.start;
4315                        if metadata_buffer_range.end > region_buffer_start {
4316                            end_position =
4317                                end_position + (metadata_buffer_range.end - region_buffer_start);
4318                        }
4319                        end_position = end_position.min(end_region.range.end);
4320                    }
4321
4322                    if start_position <= query_range.end && end_position >= query_range.start {
4323                        return Some((start_position..end_position, metadata, excerpt));
4324                    }
4325                }
4326                // When there are no more metadata items for this excerpt, move to the next excerpt.
4327                else {
4328                    current_excerpt_metadata.take();
4329                    if let Some((end_excerpt_id, _)) = range_end
4330                        && excerpt.id == end_excerpt_id
4331                    {
4332                        return None;
4333                    }
4334                    cursor.next_excerpt();
4335                }
4336            }
4337        })
4338    }
4339
4340    pub fn diff_hunk_before<T: ToOffset>(&self, position: T) -> Option<MultiBufferRow> {
4341        let offset = position.to_offset(self);
4342
4343        let mut cursor = self
4344            .cursor::<DimensionPair<MultiBufferOffset, Point>, DimensionPair<BufferOffset, Point>>(
4345            );
4346        cursor.seek(&DimensionPair {
4347            key: offset,
4348            value: None,
4349        });
4350        cursor.seek_to_start_of_current_excerpt();
4351        let excerpt = cursor.excerpt()?;
4352
4353        let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
4354        let excerpt_end = excerpt.range.context.end.to_offset(&excerpt.buffer);
4355        let current_position = self
4356            .anchor_before(offset)
4357            .text_anchor
4358            .to_offset(&excerpt.buffer);
4359
4360        if let Some(diff) = self.diffs.get(&excerpt.buffer_id) {
4361            if let Some(main_buffer) = diff.main_buffer.as_ref() {
4362                for hunk in diff.hunks_intersecting_base_text_range_rev(
4363                    excerpt_start..excerpt_end,
4364                    &main_buffer,
4365                ) {
4366                    if hunk.diff_base_byte_range.end >= current_position {
4367                        continue;
4368                    }
4369                    let hunk_start = excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start);
4370                    let start = Anchor::in_buffer(excerpt.id, hunk_start).to_point(self);
4371                    return Some(MultiBufferRow(start.row));
4372                }
4373            } else {
4374                let excerpt_end = excerpt
4375                    .buffer
4376                    .anchor_before(excerpt_end.min(current_position));
4377                for hunk in diff.hunks_intersecting_range_rev(
4378                    excerpt.range.context.start..excerpt_end,
4379                    &excerpt.buffer,
4380                ) {
4381                    let hunk_end = hunk.buffer_range.end.to_offset(&excerpt.buffer);
4382                    if hunk_end >= current_position {
4383                        continue;
4384                    }
4385                    let start =
4386                        Anchor::in_buffer(excerpt.id, hunk.buffer_range.start).to_point(self);
4387                    return Some(MultiBufferRow(start.row));
4388                }
4389            }
4390        }
4391
4392        loop {
4393            cursor.prev_excerpt();
4394            let excerpt = cursor.excerpt()?;
4395
4396            let Some(diff) = self.diffs.get(&excerpt.buffer_id) else {
4397                continue;
4398            };
4399            if let Some(main_buffer) = diff.main_buffer.as_ref() {
4400                let Some(hunk) = diff
4401                    .hunks_intersecting_base_text_range_rev(
4402                        excerpt.range.context.to_offset(&excerpt.buffer),
4403                        main_buffer,
4404                    )
4405                    .next()
4406                else {
4407                    continue;
4408                };
4409                let hunk_start = excerpt.buffer.anchor_after(hunk.diff_base_byte_range.start);
4410                let start = Anchor::in_buffer(excerpt.id, hunk_start).to_point(self);
4411                return Some(MultiBufferRow(start.row));
4412            } else {
4413                let Some(hunk) = diff
4414                    .hunks_intersecting_range_rev(excerpt.range.context.clone(), &excerpt.buffer)
4415                    .next()
4416                else {
4417                    continue;
4418                };
4419                let start = Anchor::in_buffer(excerpt.id, hunk.buffer_range.start).to_point(self);
4420                return Some(MultiBufferRow(start.row));
4421            }
4422        }
4423    }
4424
4425    pub fn has_diff_hunks(&self) -> bool {
4426        self.diffs.values().any(|diff| !diff.is_empty())
4427    }
4428
4429    pub fn is_inside_word<T: ToOffset>(
4430        &self,
4431        position: T,
4432        scope_context: Option<CharScopeContext>,
4433    ) -> bool {
4434        let position = position.to_offset(self);
4435        let classifier = self
4436            .char_classifier_at(position)
4437            .scope_context(scope_context);
4438        let next_char_kind = self.chars_at(position).next().map(|c| classifier.kind(c));
4439        let prev_char_kind = self
4440            .reversed_chars_at(position)
4441            .next()
4442            .map(|c| classifier.kind(c));
4443        prev_char_kind.zip(next_char_kind) == Some((CharKind::Word, CharKind::Word))
4444    }
4445
4446    pub fn surrounding_word<T: ToOffset>(
4447        &self,
4448        start: T,
4449        scope_context: Option<CharScopeContext>,
4450    ) -> (Range<MultiBufferOffset>, Option<CharKind>) {
4451        let mut start = start.to_offset(self);
4452        let mut end = start;
4453        let mut next_chars = self.chars_at(start).peekable();
4454        let mut prev_chars = self.reversed_chars_at(start).peekable();
4455
4456        let classifier = self.char_classifier_at(start).scope_context(scope_context);
4457
4458        let word_kind = cmp::max(
4459            prev_chars.peek().copied().map(|c| classifier.kind(c)),
4460            next_chars.peek().copied().map(|c| classifier.kind(c)),
4461        );
4462
4463        for ch in prev_chars {
4464            if Some(classifier.kind(ch)) == word_kind && ch != '\n' {
4465                start -= ch.len_utf8();
4466            } else {
4467                break;
4468            }
4469        }
4470
4471        for ch in next_chars {
4472            if Some(classifier.kind(ch)) == word_kind && ch != '\n' {
4473                end += ch.len_utf8();
4474            } else {
4475                break;
4476            }
4477        }
4478
4479        (start..end, word_kind)
4480    }
4481
4482    pub fn char_kind_before<T: ToOffset>(
4483        &self,
4484        start: T,
4485        scope_context: Option<CharScopeContext>,
4486    ) -> Option<CharKind> {
4487        let start = start.to_offset(self);
4488        let classifier = self.char_classifier_at(start).scope_context(scope_context);
4489        self.reversed_chars_at(start)
4490            .next()
4491            .map(|ch| classifier.kind(ch))
4492    }
4493
4494    pub fn is_singleton(&self) -> bool {
4495        self.singleton
4496    }
4497
4498    pub fn as_singleton(&self) -> Option<(&ExcerptId, BufferId, &BufferSnapshot)> {
4499        if self.singleton {
4500            self.excerpts
4501                .iter()
4502                .next()
4503                .map(|e| (&e.id, e.buffer_id, &e.buffer))
4504        } else {
4505            None
4506        }
4507    }
4508
4509    pub fn len(&self) -> MultiBufferOffset {
4510        self.diff_transforms.summary().output.len
4511    }
4512
4513    pub fn max_position<MBD: MultiBufferDimension>(&self) -> MBD {
4514        MBD::from_summary(&self.text_summary())
4515    }
4516
4517    pub fn is_empty(&self) -> bool {
4518        self.diff_transforms.summary().output.len == MultiBufferOffset(0)
4519    }
4520
4521    pub fn widest_line_number(&self) -> u32 {
4522        // widest_line_number is 0-based, so 1 is added to get the displayed line number.
4523        self.excerpts.summary().widest_line_number + 1
4524    }
4525
4526    pub fn bytes_in_range<T: ToOffset>(&self, range: Range<T>) -> MultiBufferBytes<'_> {
4527        let range = range.start.to_offset(self)..range.end.to_offset(self);
4528        let mut excerpts = self.cursor::<MultiBufferOffset, BufferOffset>();
4529        excerpts.seek(&range.start);
4530
4531        let mut chunk;
4532        let mut has_trailing_newline;
4533        let excerpt_bytes;
4534        if let Some(region) = excerpts.region() {
4535            let mut bytes = region.buffer.bytes_in_range(
4536                region.buffer_range.start + (range.start - region.range.start)
4537                    ..(region.buffer_range.start + (range.end - region.range.start))
4538                        .min(region.buffer_range.end),
4539            );
4540            chunk = bytes.next().unwrap_or(&[][..]);
4541            excerpt_bytes = Some(bytes);
4542            has_trailing_newline = region.has_trailing_newline && range.end >= region.range.end;
4543            if chunk.is_empty() && has_trailing_newline {
4544                chunk = b"\n";
4545                has_trailing_newline = false;
4546            }
4547        } else {
4548            chunk = &[][..];
4549            excerpt_bytes = None;
4550            has_trailing_newline = false;
4551        };
4552
4553        MultiBufferBytes {
4554            range,
4555            cursor: excerpts,
4556            excerpt_bytes,
4557            has_trailing_newline,
4558            chunk,
4559        }
4560    }
4561
4562    pub fn reversed_bytes_in_range<T: ToOffset>(
4563        &self,
4564        range: Range<T>,
4565    ) -> ReversedMultiBufferBytes<'_> {
4566        let range = range.start.to_offset(self)..range.end.to_offset(self);
4567        let mut chunks = self.reversed_chunks_in_range(range.clone());
4568        let chunk = chunks.next().map_or(&[][..], |c| c.as_bytes());
4569        ReversedMultiBufferBytes {
4570            range,
4571            chunks,
4572            chunk,
4573        }
4574    }
4575
4576    pub fn row_infos(&self, start_row: MultiBufferRow) -> MultiBufferRows<'_> {
4577        let mut cursor = self.cursor::<Point, Point>();
4578        cursor.seek(&Point::new(start_row.0, 0));
4579        let mut result = MultiBufferRows {
4580            point: Point::new(0, 0),
4581            is_empty: self.excerpts.is_empty(),
4582            is_singleton: self.is_singleton(),
4583            cursor,
4584        };
4585        result.seek(start_row);
4586        result
4587    }
4588
4589    pub fn chunks<T: ToOffset>(
4590        &self,
4591        range: Range<T>,
4592        language_aware: bool,
4593    ) -> MultiBufferChunks<'_> {
4594        let mut chunks = MultiBufferChunks {
4595            excerpt_offset_range: ExcerptDimension(MultiBufferOffset::ZERO)
4596                ..ExcerptDimension(MultiBufferOffset::ZERO),
4597            range: MultiBufferOffset::ZERO..MultiBufferOffset::ZERO,
4598            excerpts: self.excerpts.cursor(()),
4599            diff_transforms: self.diff_transforms.cursor(()),
4600            diffs: &self.diffs,
4601            diff_base_chunks: None,
4602            excerpt_chunks: None,
4603            buffer_chunk: None,
4604            language_aware,
4605        };
4606        let range = range.start.to_offset(self)..range.end.to_offset(self);
4607        chunks.seek(range);
4608        chunks
4609    }
4610
4611    pub fn clip_offset(&self, offset: MultiBufferOffset, bias: Bias) -> MultiBufferOffset {
4612        self.clip_dimension(offset, bias, text::BufferSnapshot::clip_offset)
4613    }
4614
4615    pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
4616        self.clip_dimension(point, bias, text::BufferSnapshot::clip_point)
4617    }
4618
4619    pub fn clip_offset_utf16(
4620        &self,
4621        offset: MultiBufferOffsetUtf16,
4622        bias: Bias,
4623    ) -> MultiBufferOffsetUtf16 {
4624        self.clip_dimension(offset, bias, text::BufferSnapshot::clip_offset_utf16)
4625    }
4626
4627    pub fn clip_point_utf16(&self, point: Unclipped<PointUtf16>, bias: Bias) -> PointUtf16 {
4628        self.clip_dimension(point.0, bias, |buffer, point, bias| {
4629            buffer.clip_point_utf16(Unclipped(point), bias)
4630        })
4631    }
4632
4633    pub fn offset_to_point(&self, offset: MultiBufferOffset) -> Point {
4634        self.convert_dimension(offset, text::BufferSnapshot::offset_to_point)
4635    }
4636
4637    pub fn offset_to_point_utf16(&self, offset: MultiBufferOffset) -> PointUtf16 {
4638        self.convert_dimension(offset, text::BufferSnapshot::offset_to_point_utf16)
4639    }
4640
4641    pub fn point_to_point_utf16(&self, point: Point) -> PointUtf16 {
4642        self.convert_dimension(point, text::BufferSnapshot::point_to_point_utf16)
4643    }
4644
4645    pub fn point_utf16_to_point(&self, point: PointUtf16) -> Point {
4646        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_point)
4647    }
4648
4649    #[instrument(skip_all)]
4650    pub fn point_to_offset(&self, point: Point) -> MultiBufferOffset {
4651        self.convert_dimension(point, text::BufferSnapshot::point_to_offset)
4652    }
4653
4654    pub fn point_to_offset_utf16(&self, point: Point) -> MultiBufferOffsetUtf16 {
4655        self.convert_dimension(point, text::BufferSnapshot::point_to_offset_utf16)
4656    }
4657
4658    pub fn offset_utf16_to_offset(&self, offset: MultiBufferOffsetUtf16) -> MultiBufferOffset {
4659        self.convert_dimension(offset, text::BufferSnapshot::offset_utf16_to_offset)
4660    }
4661
4662    pub fn offset_to_offset_utf16(&self, offset: MultiBufferOffset) -> MultiBufferOffsetUtf16 {
4663        self.convert_dimension(offset, text::BufferSnapshot::offset_to_offset_utf16)
4664    }
4665
4666    pub fn point_utf16_to_offset(&self, point: PointUtf16) -> MultiBufferOffset {
4667        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_offset)
4668    }
4669
4670    pub fn point_utf16_to_offset_utf16(&self, point: PointUtf16) -> MultiBufferOffsetUtf16 {
4671        self.convert_dimension(point, text::BufferSnapshot::point_utf16_to_offset_utf16)
4672    }
4673
4674    fn clip_dimension<MBD, BD>(
4675        &self,
4676        position: MBD,
4677        bias: Bias,
4678        clip_buffer_position: fn(&text::BufferSnapshot, BD, Bias) -> BD,
4679    ) -> MBD
4680    where
4681        MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
4682        BD: TextDimension + Sub<Output = <MBD as Sub>::Output> + AddAssign<<MBD as Sub>::Output>,
4683    {
4684        let mut cursor = self.cursor::<MBD, BD>();
4685        cursor.seek(&position);
4686        if let Some(region) = cursor.region() {
4687            if position >= region.range.end {
4688                return region.range.end;
4689            }
4690            let overshoot = position - region.range.start;
4691            let mut buffer_position = region.buffer_range.start;
4692            buffer_position += overshoot;
4693            let clipped_buffer_position =
4694                clip_buffer_position(region.buffer, buffer_position, bias);
4695            let mut position = region.range.start;
4696            position += clipped_buffer_position - region.buffer_range.start;
4697            position
4698        } else {
4699            self.max_position()
4700        }
4701    }
4702
4703    #[instrument(skip_all)]
4704    fn convert_dimension<MBR1, MBR2, BR1, BR2>(
4705        &self,
4706        key: MBR1,
4707        convert_buffer_dimension: fn(&text::BufferSnapshot, BR1) -> BR2,
4708    ) -> MBR2
4709    where
4710        MBR1: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBR1 as Sub>::Output>,
4711        BR1: TextDimension + Sub<Output = <MBR1 as Sub>::Output> + AddAssign<<MBR1 as Sub>::Output>,
4712        MBR2: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBR2 as Sub>::Output>,
4713        BR2: TextDimension + Sub<Output = <MBR2 as Sub>::Output> + AddAssign<<MBR2 as Sub>::Output>,
4714    {
4715        let mut cursor = self.cursor::<DimensionPair<MBR1, MBR2>, DimensionPair<BR1, BR2>>();
4716        cursor.seek(&DimensionPair { key, value: None });
4717        if let Some(region) = cursor.region() {
4718            if key >= region.range.end.key {
4719                return region.range.end.value.unwrap();
4720            }
4721            let start_key = region.range.start.key;
4722            let start_value = region.range.start.value.unwrap();
4723            let buffer_start_key = region.buffer_range.start.key;
4724            let buffer_start_value = region.buffer_range.start.value.unwrap();
4725            let mut buffer_key = buffer_start_key;
4726            buffer_key += key - start_key;
4727            let buffer_value = convert_buffer_dimension(region.buffer, buffer_key);
4728            let mut result = start_value;
4729            result += buffer_value - buffer_start_value;
4730            result
4731        } else {
4732            self.max_position()
4733        }
4734    }
4735
4736    pub fn point_to_buffer_offset<T: ToOffset>(
4737        &self,
4738        point: T,
4739    ) -> Option<(&BufferSnapshot, BufferOffset)> {
4740        let offset = point.to_offset(self);
4741        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
4742        cursor.seek(&offset);
4743        let region = cursor.region()?;
4744        let overshoot = offset - region.range.start;
4745        let buffer_offset = region.buffer_range.start + overshoot;
4746        if buffer_offset == BufferOffset(region.buffer.len() + 1)
4747            && region.has_trailing_newline
4748            && !region.is_main_buffer
4749        {
4750            let main_buffer_position = cursor.main_buffer_position()?;
4751            let buffer_snapshot = &cursor.excerpt()?.buffer;
4752            return Some((buffer_snapshot, main_buffer_position));
4753        } else if buffer_offset > BufferOffset(region.buffer.len()) {
4754            return None;
4755        }
4756        Some((region.buffer, buffer_offset))
4757    }
4758
4759    pub fn point_to_buffer_point(
4760        &self,
4761        point: Point,
4762    ) -> Option<(&BufferSnapshot, Point, ExcerptId)> {
4763        let mut cursor = self.cursor::<Point, Point>();
4764        cursor.seek(&point);
4765        let region = cursor.region()?;
4766        let overshoot = point - region.range.start;
4767        let buffer_point = region.buffer_range.start + overshoot;
4768        let excerpt = cursor.excerpt()?;
4769        if buffer_point == region.buffer.max_point() + Point::new(1, 0)
4770            && region.has_trailing_newline
4771            && !region.is_main_buffer
4772        {
4773            return Some((&excerpt.buffer, cursor.main_buffer_position()?, excerpt.id));
4774        } else if buffer_point > region.buffer.max_point() {
4775            return None;
4776        }
4777        Some((region.buffer, buffer_point, excerpt.id))
4778    }
4779
4780    pub fn suggested_indents(
4781        &self,
4782        rows: impl IntoIterator<Item = u32>,
4783        cx: &App,
4784    ) -> BTreeMap<MultiBufferRow, IndentSize> {
4785        let mut result = BTreeMap::new();
4786        self.suggested_indents_callback(
4787            rows,
4788            |row, indent| {
4789                result.insert(row, indent);
4790                ControlFlow::Continue(())
4791            },
4792            cx,
4793        );
4794        result
4795    }
4796
4797    // move this to be a generator once those are a thing
4798    pub fn suggested_indents_callback(
4799        &self,
4800        rows: impl IntoIterator<Item = u32>,
4801        mut cb: impl FnMut(MultiBufferRow, IndentSize) -> ControlFlow<()>,
4802        cx: &App,
4803    ) {
4804        let mut rows_for_excerpt = Vec::new();
4805        let mut cursor = self.cursor::<Point, Point>();
4806        let mut rows = rows.into_iter().peekable();
4807        let mut prev_row = u32::MAX;
4808        let mut prev_language_indent_size = IndentSize::default();
4809
4810        while let Some(row) = rows.next() {
4811            cursor.seek(&Point::new(row, 0));
4812            let Some(region) = cursor.region() else {
4813                continue;
4814            };
4815
4816            // Retrieve the language and indent size once for each disjoint region being indented.
4817            let single_indent_size = if row.saturating_sub(1) == prev_row {
4818                prev_language_indent_size
4819            } else {
4820                region
4821                    .buffer
4822                    .language_indent_size_at(Point::new(row, 0), cx)
4823            };
4824            prev_language_indent_size = single_indent_size;
4825            prev_row = row;
4826
4827            let start_buffer_row = region.buffer_range.start.row;
4828            let start_multibuffer_row = region.range.start.row;
4829            let end_multibuffer_row = region.range.end.row;
4830
4831            rows_for_excerpt.push(row);
4832            while let Some(next_row) = rows.peek().copied() {
4833                if end_multibuffer_row > next_row {
4834                    rows_for_excerpt.push(next_row);
4835                    rows.next();
4836                } else {
4837                    break;
4838                }
4839            }
4840
4841            let buffer_rows = rows_for_excerpt
4842                .drain(..)
4843                .map(|row| start_buffer_row + row - start_multibuffer_row);
4844            let buffer_indents = region
4845                .buffer
4846                .suggested_indents(buffer_rows, single_indent_size);
4847            for (row, indent) in buffer_indents {
4848                if cb(
4849                    MultiBufferRow(start_multibuffer_row + row - start_buffer_row),
4850                    indent,
4851                )
4852                .is_break()
4853                {
4854                    return;
4855                }
4856            }
4857        }
4858    }
4859
4860    pub fn indent_size_for_line(&self, row: MultiBufferRow) -> IndentSize {
4861        if let Some((buffer, range)) = self.buffer_line_for_row(row) {
4862            let mut size = buffer.indent_size_for_line(range.start.row);
4863            size.len = size
4864                .len
4865                .min(range.end.column)
4866                .saturating_sub(range.start.column);
4867            size
4868        } else {
4869            IndentSize::spaces(0)
4870        }
4871    }
4872
4873    pub fn line_indent_for_row(&self, row: MultiBufferRow) -> LineIndent {
4874        if let Some((buffer, range)) = self.buffer_line_for_row(row) {
4875            LineIndent::from_iter(buffer.text_for_range(range).flat_map(|s| s.chars()))
4876        } else {
4877            LineIndent::spaces(0)
4878        }
4879    }
4880
4881    pub fn indent_and_comment_for_line(&self, row: MultiBufferRow, cx: &App) -> String {
4882        let mut indent = self.indent_size_for_line(row).chars().collect::<String>();
4883
4884        if self.language_settings(cx).extend_comment_on_newline
4885            && let Some(language_scope) = self.language_scope_at(Point::new(row.0, 0))
4886        {
4887            let delimiters = language_scope.line_comment_prefixes();
4888            for delimiter in delimiters {
4889                if *self
4890                    .chars_at(Point::new(row.0, indent.len() as u32))
4891                    .take(delimiter.chars().count())
4892                    .collect::<String>()
4893                    .as_str()
4894                    == **delimiter
4895                {
4896                    indent.push_str(delimiter);
4897                    break;
4898                }
4899            }
4900        }
4901
4902        indent
4903    }
4904
4905    pub fn is_line_whitespace_upto<T>(&self, position: T) -> bool
4906    where
4907        T: ToOffset,
4908    {
4909        for char in self.reversed_chars_at(position) {
4910            if !char.is_whitespace() {
4911                return false;
4912            }
4913            if char == '\n' {
4914                return true;
4915            }
4916        }
4917        true
4918    }
4919
4920    pub fn prev_non_blank_row(&self, mut row: MultiBufferRow) -> Option<MultiBufferRow> {
4921        while row.0 > 0 {
4922            row.0 -= 1;
4923            if !self.is_line_blank(row) {
4924                return Some(row);
4925            }
4926        }
4927        None
4928    }
4929
4930    pub fn line_len(&self, row: MultiBufferRow) -> u32 {
4931        if let Some((_, range)) = self.buffer_line_for_row(row) {
4932            range.end.column - range.start.column
4933        } else {
4934            0
4935        }
4936    }
4937
4938    pub fn buffer_line_for_row(
4939        &self,
4940        row: MultiBufferRow,
4941    ) -> Option<(&BufferSnapshot, Range<Point>)> {
4942        let mut cursor = self.cursor::<Point, Point>();
4943        let point = Point::new(row.0, 0);
4944        cursor.seek(&point);
4945        let region = cursor.region()?;
4946        let overshoot = point.min(region.range.end) - region.range.start;
4947        let buffer_point = region.buffer_range.start + overshoot;
4948        if buffer_point.row > region.buffer_range.end.row {
4949            return None;
4950        }
4951        let line_start = Point::new(buffer_point.row, 0).max(region.buffer_range.start);
4952        let line_end = Point::new(buffer_point.row, region.buffer.line_len(buffer_point.row))
4953            .min(region.buffer_range.end);
4954        Some((region.buffer, line_start..line_end))
4955    }
4956
4957    pub fn max_point(&self) -> Point {
4958        self.text_summary().lines
4959    }
4960
4961    pub fn max_row(&self) -> MultiBufferRow {
4962        MultiBufferRow(self.text_summary().lines.row)
4963    }
4964
4965    pub fn text_summary(&self) -> MBTextSummary {
4966        self.diff_transforms.summary().output
4967    }
4968
4969    pub fn text_summary_for_range<MBD, O>(&self, range: Range<O>) -> MBD
4970    where
4971        MBD: MultiBufferDimension + AddAssign,
4972        O: ToOffset,
4973    {
4974        let range = range.start.to_offset(self)..range.end.to_offset(self);
4975        let mut cursor = self
4976            .diff_transforms
4977            .cursor::<Dimensions<MultiBufferOffset, ExcerptOffset>>(());
4978        cursor.seek(&range.start, Bias::Right);
4979
4980        let Some(first_transform) = cursor.item() else {
4981            return MBD::from_summary(&MBTextSummary::default());
4982        };
4983
4984        let diff_transform_start = cursor.start().0;
4985        let diff_transform_end = cursor.end().0;
4986        let diff_start = range.start;
4987        let start_overshoot = diff_start - diff_transform_start;
4988        let end_overshoot = std::cmp::min(range.end, diff_transform_end) - diff_transform_start;
4989
4990        let mut result = match first_transform {
4991            DiffTransform::BufferContent { .. } => {
4992                let excerpt_start = cursor.start().1 + start_overshoot;
4993                let excerpt_end = cursor.start().1 + end_overshoot;
4994                self.text_summary_for_excerpt_offset_range(excerpt_start..excerpt_end)
4995            }
4996            DiffTransform::DeletedHunk {
4997                buffer_id,
4998                base_text_byte_range,
4999                has_trailing_newline,
5000                ..
5001            } => {
5002                let buffer_start = base_text_byte_range.start + start_overshoot;
5003                let mut buffer_end = base_text_byte_range.start + end_overshoot;
5004                let Some(base_text) = self.diffs.get(buffer_id).map(|diff| diff.base_text()) else {
5005                    panic!("{:?} is in non-existent deleted hunk", range.start)
5006                };
5007
5008                let include_trailing_newline =
5009                    *has_trailing_newline && range.end >= diff_transform_end;
5010                if include_trailing_newline {
5011                    buffer_end -= 1;
5012                }
5013
5014                let mut summary = base_text
5015                    .text_summary_for_range::<MBD::TextDimension, _>(buffer_start..buffer_end);
5016
5017                if include_trailing_newline {
5018                    summary.add_assign(&<MBD::TextDimension>::from_text_summary(
5019                        &TextSummary::newline(),
5020                    ))
5021                }
5022
5023                let mut result = MBD::default();
5024                result.add_text_dim(&summary);
5025                result
5026            }
5027        };
5028        if range.end < diff_transform_end {
5029            return result;
5030        }
5031
5032        cursor.next();
5033        result.add_mb_text_summary(
5034            &cursor
5035                .summary::<_, OutputDimension<_>>(&range.end, Bias::Right)
5036                .0,
5037        );
5038
5039        let Some(last_transform) = cursor.item() else {
5040            return result;
5041        };
5042
5043        let overshoot = range.end - cursor.start().0;
5044        let suffix = match last_transform {
5045            DiffTransform::BufferContent { .. } => {
5046                let end = cursor.start().1 + overshoot;
5047                self.text_summary_for_excerpt_offset_range::<MBD>(cursor.start().1..end)
5048            }
5049            DiffTransform::DeletedHunk {
5050                base_text_byte_range,
5051                buffer_id,
5052                has_trailing_newline,
5053                ..
5054            } => {
5055                let buffer_end = base_text_byte_range.start + overshoot;
5056                let Some(base_text) = self.diffs.get(buffer_id).map(|diff| diff.base_text()) else {
5057                    panic!("{:?} is in non-existent deleted hunk", range.end)
5058                };
5059
5060                let mut suffix = base_text.text_summary_for_range::<MBD::TextDimension, _>(
5061                    base_text_byte_range.start..buffer_end,
5062                );
5063                if *has_trailing_newline && buffer_end == base_text_byte_range.end + 1 {
5064                    suffix.add_assign(&<MBD::TextDimension>::from_text_summary(
5065                        &TextSummary::from("\n"),
5066                    ))
5067                }
5068
5069                let mut result = MBD::default();
5070                result.add_text_dim(&suffix);
5071                result
5072            }
5073        };
5074
5075        result += suffix;
5076        result
5077    }
5078
5079    fn text_summary_for_excerpt_offset_range<MBD>(&self, mut range: Range<ExcerptOffset>) -> MBD
5080    where
5081        MBD: MultiBufferDimension + AddAssign,
5082    {
5083        let mut summary = MBD::default();
5084        let mut cursor = self.excerpts.cursor::<ExcerptOffset>(());
5085        cursor.seek(&range.start, Bias::Right);
5086        if let Some(excerpt) = cursor.item() {
5087            let mut end_before_newline = cursor.end();
5088            if excerpt.has_trailing_newline {
5089                end_before_newline -= 1;
5090            }
5091
5092            let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
5093            let start_in_excerpt = excerpt_start + (range.start - *cursor.start());
5094            let end_in_excerpt =
5095                excerpt_start + (cmp::min(end_before_newline, range.end) - *cursor.start());
5096            summary.add_text_dim(
5097                &excerpt
5098                    .buffer
5099                    .text_summary_for_range::<MBD::TextDimension, _>(
5100                        start_in_excerpt..end_in_excerpt,
5101                    ),
5102            );
5103
5104            if range.end > end_before_newline {
5105                summary.add_mb_text_summary(&MBTextSummary::from(TextSummary::newline()));
5106            }
5107
5108            cursor.next();
5109        }
5110
5111        if range.end > *cursor.start() {
5112            summary += cursor
5113                .summary::<_, ExcerptDimension<MBD>>(&range.end, Bias::Right)
5114                .0;
5115            if let Some(excerpt) = cursor.item() {
5116                range.end = cmp::max(*cursor.start(), range.end);
5117
5118                let excerpt_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
5119                let end_in_excerpt = excerpt_start + (range.end - *cursor.start());
5120                summary.add_text_dim(
5121                    &excerpt
5122                        .buffer
5123                        .text_summary_for_range::<MBD::TextDimension, _>(
5124                            excerpt_start..end_in_excerpt,
5125                        ),
5126                );
5127            }
5128        }
5129
5130        summary
5131    }
5132
5133    pub fn summary_for_anchor<MBD>(&self, anchor: &Anchor) -> MBD
5134    where
5135        MBD: MultiBufferDimension
5136            + Ord
5137            + Sub<Output = MBD::TextDimension>
5138            + AddAssign<MBD::TextDimension>,
5139        MBD::TextDimension: Sub<Output = MBD::TextDimension> + Ord,
5140    {
5141        self.summaries_for_anchors([anchor])[0]
5142    }
5143
5144    fn resolve_summary_for_anchor<MBD>(
5145        &self,
5146        anchor: &Anchor,
5147        excerpt_position: ExcerptDimension<MBD>,
5148        diff_transforms: &mut Cursor<
5149            DiffTransform,
5150            Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>,
5151        >,
5152    ) -> MBD
5153    where
5154        MBD: MultiBufferDimension + Ord + Sub + AddAssign<<MBD as Sub>::Output>,
5155    {
5156        loop {
5157            let transform_end_position = diff_transforms.end().0;
5158            let at_transform_end =
5159                transform_end_position == excerpt_position && diff_transforms.item().is_some();
5160            if at_transform_end && anchor.text_anchor.bias == Bias::Right {
5161                diff_transforms.next();
5162                continue;
5163            }
5164
5165            let mut position = diff_transforms.start().1;
5166            match diff_transforms.item() {
5167                Some(DiffTransform::DeletedHunk {
5168                    buffer_id,
5169                    base_text_byte_range,
5170                    ..
5171                }) => {
5172                    if let Some(diff_base_anchor) = &anchor.diff_base_anchor
5173                        && let Some(base_text) =
5174                            self.diffs.get(buffer_id).map(|diff| diff.base_text())
5175                        && diff_base_anchor.is_valid(&base_text)
5176                    {
5177                        let base_text_offset = diff_base_anchor.to_offset(base_text);
5178                        if base_text_offset >= base_text_byte_range.start
5179                            && base_text_offset <= base_text_byte_range.end
5180                        {
5181                            let position_in_hunk = base_text
5182                                .text_summary_for_range::<MBD::TextDimension, _>(
5183                                    base_text_byte_range.start..base_text_offset,
5184                                );
5185                            position.0.add_text_dim(&position_in_hunk);
5186                        } else if at_transform_end {
5187                            diff_transforms.next();
5188                            continue;
5189                        }
5190                    }
5191                }
5192                _ => {
5193                    if at_transform_end && anchor.diff_base_anchor.is_some() {
5194                        diff_transforms.next();
5195                        continue;
5196                    }
5197                    let overshoot = excerpt_position - diff_transforms.start().0;
5198                    position += overshoot;
5199                }
5200            }
5201
5202            return position.0;
5203        }
5204    }
5205
5206    fn excerpt_offset_for_anchor(&self, anchor: &Anchor) -> ExcerptOffset {
5207        let mut cursor = self
5208            .excerpts
5209            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
5210        let locator = self.excerpt_locator_for_id(anchor.excerpt_id);
5211
5212        cursor.seek(&Some(locator), Bias::Left);
5213        if cursor.item().is_none() && anchor.excerpt_id == ExcerptId::max() {
5214            cursor.prev();
5215        }
5216
5217        let mut position = cursor.start().1;
5218        if let Some(excerpt) = cursor.item()
5219            && (excerpt.id == anchor.excerpt_id || anchor.excerpt_id == ExcerptId::max())
5220        {
5221            let excerpt_buffer_start = excerpt
5222                .buffer
5223                .offset_for_anchor(&excerpt.range.context.start);
5224            let excerpt_buffer_end = excerpt.buffer.offset_for_anchor(&excerpt.range.context.end);
5225            let buffer_position = cmp::min(
5226                excerpt_buffer_end,
5227                excerpt.buffer.offset_for_anchor(&anchor.text_anchor),
5228            );
5229            if buffer_position > excerpt_buffer_start {
5230                position += buffer_position - excerpt_buffer_start;
5231            }
5232        }
5233        position
5234    }
5235
5236    pub fn latest_excerpt_id(&self, mut excerpt_id: ExcerptId) -> ExcerptId {
5237        while let Some(replacement) = self.replaced_excerpts.get(&excerpt_id) {
5238            excerpt_id = *replacement;
5239        }
5240        excerpt_id
5241    }
5242
5243    pub fn summaries_for_anchors<'a, MBD, I>(&'a self, anchors: I) -> Vec<MBD>
5244    where
5245        MBD: MultiBufferDimension
5246            + Ord
5247            + Sub<Output = MBD::TextDimension>
5248            + AddAssign<MBD::TextDimension>,
5249        MBD::TextDimension: Sub<Output = MBD::TextDimension> + Ord,
5250        I: 'a + IntoIterator<Item = &'a Anchor>,
5251    {
5252        let mut anchors = anchors.into_iter().peekable();
5253        let mut cursor = self.excerpts.cursor::<ExcerptSummary>(());
5254        let mut diff_transforms_cursor = self
5255            .diff_transforms
5256            .cursor::<Dimensions<ExcerptDimension<MBD>, OutputDimension<MBD>>>(());
5257        diff_transforms_cursor.next();
5258
5259        let mut summaries = Vec::new();
5260        while let Some(anchor) = anchors.peek() {
5261            let excerpt_id = self.latest_excerpt_id(anchor.excerpt_id);
5262
5263            let excerpt_anchors = anchors.peeking_take_while(|anchor| {
5264                self.latest_excerpt_id(anchor.excerpt_id) == excerpt_id
5265            });
5266
5267            let locator = self.excerpt_locator_for_id(excerpt_id);
5268            cursor.seek_forward(locator, Bias::Left);
5269            if cursor.item().is_none() && excerpt_id == ExcerptId::max() {
5270                cursor.prev();
5271            }
5272
5273            let excerpt_start_position = ExcerptDimension(MBD::from_summary(&cursor.start().text));
5274            if let Some(excerpt) = cursor.item() {
5275                if excerpt.id != excerpt_id && excerpt_id != ExcerptId::max() {
5276                    let position = self.resolve_summary_for_anchor(
5277                        &Anchor::min(),
5278                        excerpt_start_position,
5279                        &mut diff_transforms_cursor,
5280                    );
5281                    summaries.extend(excerpt_anchors.map(|_| position));
5282                    continue;
5283                }
5284                let excerpt_buffer_start = excerpt
5285                    .range
5286                    .context
5287                    .start
5288                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5289                let excerpt_buffer_end = excerpt
5290                    .range
5291                    .context
5292                    .end
5293                    .summary::<MBD::TextDimension>(&excerpt.buffer);
5294                for (buffer_summary, anchor) in excerpt
5295                    .buffer
5296                    .summaries_for_anchors_with_payload::<MBD::TextDimension, _, _>(
5297                        excerpt_anchors.map(|a| (&a.text_anchor, a)),
5298                    )
5299                {
5300                    let summary = cmp::min(excerpt_buffer_end, buffer_summary);
5301                    let mut position = excerpt_start_position;
5302                    if summary > excerpt_buffer_start {
5303                        position += summary - excerpt_buffer_start;
5304                    }
5305
5306                    if diff_transforms_cursor.start().0 < position {
5307                        diff_transforms_cursor.seek_forward(&position, Bias::Left);
5308                    }
5309
5310                    summaries.push(self.resolve_summary_for_anchor(
5311                        anchor,
5312                        position,
5313                        &mut diff_transforms_cursor,
5314                    ));
5315                }
5316            } else {
5317                diff_transforms_cursor.seek_forward(&excerpt_start_position, Bias::Left);
5318                let position = self.resolve_summary_for_anchor(
5319                    &Anchor::max(),
5320                    excerpt_start_position,
5321                    &mut diff_transforms_cursor,
5322                );
5323                summaries.extend(excerpt_anchors.map(|_| position));
5324            }
5325        }
5326
5327        summaries
5328    }
5329
5330    pub fn dimensions_from_points<'a, MBD>(
5331        &'a self,
5332        points: impl 'a + IntoIterator<Item = Point>,
5333    ) -> impl 'a + Iterator<Item = MBD>
5334    where
5335        MBD: MultiBufferDimension + Sub + AddAssign<<MBD as Sub>::Output>,
5336    {
5337        let mut cursor = self.cursor::<DimensionPair<Point, MBD>, Point>();
5338        cursor.seek(&DimensionPair {
5339            key: Point::default(),
5340            value: None,
5341        });
5342        let mut points = points.into_iter();
5343        iter::from_fn(move || {
5344            let point = points.next()?;
5345
5346            cursor.seek_forward(&DimensionPair {
5347                key: point,
5348                value: None,
5349            });
5350
5351            if let Some(region) = cursor.region() {
5352                let overshoot = point - region.range.start.key;
5353                let buffer_point = region.buffer_range.start + overshoot;
5354                let mut position = region.range.start.value.unwrap();
5355                position.add_text_dim(
5356                    &region
5357                        .buffer
5358                        .text_summary_for_range(region.buffer_range.start..buffer_point),
5359                );
5360                if point == region.range.end.key && region.has_trailing_newline {
5361                    position.add_mb_text_summary(&MBTextSummary::from(TextSummary::newline()));
5362                }
5363                Some(position)
5364            } else {
5365                Some(MBD::from_summary(&self.text_summary()))
5366            }
5367        })
5368    }
5369
5370    pub fn refresh_anchors<'a, I>(&'a self, anchors: I) -> Vec<(usize, Anchor, bool)>
5371    where
5372        I: 'a + IntoIterator<Item = &'a Anchor>,
5373    {
5374        let mut anchors = anchors.into_iter().enumerate().peekable();
5375        let mut cursor = self.excerpts.cursor::<Option<&Locator>>(());
5376        cursor.next();
5377
5378        let mut result = Vec::new();
5379
5380        while let Some((_, anchor)) = anchors.peek() {
5381            let old_excerpt_id = anchor.excerpt_id;
5382
5383            // Find the location where this anchor's excerpt should be.
5384            let old_locator = self.excerpt_locator_for_id(old_excerpt_id);
5385            cursor.seek_forward(&Some(old_locator), Bias::Left);
5386
5387            let next_excerpt = cursor.item();
5388            let prev_excerpt = cursor.prev_item();
5389
5390            // Process all of the anchors for this excerpt.
5391            while let Some((anchor_ix, &anchor)) =
5392                anchors.next_if(|(_, anchor)| anchor.excerpt_id == old_excerpt_id)
5393            {
5394                let mut anchor = anchor;
5395
5396                // Leave min and max anchors unchanged if invalid or
5397                // if the old excerpt still exists at this location
5398                let mut kept_position = next_excerpt
5399                    .is_some_and(|e| e.id == old_excerpt_id && e.contains(&anchor))
5400                    || old_excerpt_id == ExcerptId::max()
5401                    || old_excerpt_id == ExcerptId::min();
5402
5403                // If the old excerpt no longer exists at this location, then attempt to
5404                // find an equivalent position for this anchor in an adjacent excerpt.
5405                if !kept_position {
5406                    for excerpt in [next_excerpt, prev_excerpt].iter().filter_map(|e| *e) {
5407                        if excerpt.contains(&anchor) {
5408                            anchor.excerpt_id = excerpt.id;
5409                            kept_position = true;
5410                            break;
5411                        }
5412                    }
5413                }
5414
5415                // If there's no adjacent excerpt that contains the anchor's position,
5416                // then report that the anchor has lost its position.
5417                if !kept_position {
5418                    anchor = if let Some(excerpt) = next_excerpt {
5419                        let mut text_anchor = excerpt
5420                            .range
5421                            .context
5422                            .start
5423                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
5424                        if text_anchor
5425                            .cmp(&excerpt.range.context.end, &excerpt.buffer)
5426                            .is_gt()
5427                        {
5428                            text_anchor = excerpt.range.context.end;
5429                        }
5430                        Anchor::in_buffer(excerpt.id, text_anchor)
5431                    } else if let Some(excerpt) = prev_excerpt {
5432                        let mut text_anchor = excerpt
5433                            .range
5434                            .context
5435                            .end
5436                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
5437                        if text_anchor
5438                            .cmp(&excerpt.range.context.start, &excerpt.buffer)
5439                            .is_lt()
5440                        {
5441                            text_anchor = excerpt.range.context.start;
5442                        }
5443                        Anchor::in_buffer(excerpt.id, text_anchor)
5444                    } else if anchor.text_anchor.bias == Bias::Left {
5445                        Anchor::min()
5446                    } else {
5447                        Anchor::max()
5448                    };
5449                }
5450
5451                result.push((anchor_ix, anchor, kept_position));
5452            }
5453        }
5454        result.sort_unstable_by(|a, b| a.1.cmp(&b.1, self));
5455        result
5456    }
5457
5458    pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
5459        self.anchor_at(position, Bias::Left)
5460    }
5461
5462    pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
5463        self.anchor_at(position, Bias::Right)
5464    }
5465
5466    pub fn anchor_at<T: ToOffset>(&self, position: T, mut bias: Bias) -> Anchor {
5467        let offset = position.to_offset(self);
5468
5469        // Find the given position in the diff transforms. Determine the corresponding
5470        // offset in the excerpts, and whether the position is within a deleted hunk.
5471        let mut diff_transforms = self
5472            .diff_transforms
5473            .cursor::<Dimensions<MultiBufferOffset, ExcerptOffset>>(());
5474        diff_transforms.seek(&offset, Bias::Right);
5475
5476        if offset == diff_transforms.start().0
5477            && bias == Bias::Left
5478            && let Some(prev_item) = diff_transforms.prev_item()
5479            && let DiffTransform::DeletedHunk { .. } = prev_item
5480        {
5481            diff_transforms.prev();
5482        }
5483        let offset_in_transform = offset - diff_transforms.start().0;
5484        let mut excerpt_offset = diff_transforms.start().1;
5485        let mut diff_base_anchor = None;
5486        if let Some(DiffTransform::DeletedHunk {
5487            buffer_id,
5488            base_text_byte_range,
5489            has_trailing_newline,
5490            ..
5491        }) = diff_transforms.item()
5492        {
5493            let diff = self.diffs.get(buffer_id).expect("missing diff");
5494            if offset_in_transform > base_text_byte_range.len() {
5495                debug_assert!(*has_trailing_newline);
5496                bias = Bias::Right;
5497            } else {
5498                diff_base_anchor = Some(
5499                    diff.base_text()
5500                        .anchor_at(base_text_byte_range.start + offset_in_transform, bias),
5501                );
5502                bias = Bias::Left;
5503            }
5504        } else {
5505            excerpt_offset += MultiBufferOffset(offset_in_transform);
5506        };
5507
5508        let mut excerpts = self
5509            .excerpts
5510            .cursor::<Dimensions<ExcerptOffset, Option<ExcerptId>>>(());
5511        excerpts.seek(&excerpt_offset, Bias::Right);
5512        if excerpts.item().is_none() && excerpt_offset == excerpts.start().0 && bias == Bias::Left {
5513            excerpts.prev();
5514        }
5515        if let Some(excerpt) = excerpts.item() {
5516            let mut overshoot = excerpt_offset.saturating_sub(excerpts.start().0);
5517            if excerpt.has_trailing_newline && excerpt_offset == excerpts.end().0 {
5518                overshoot -= 1;
5519                bias = Bias::Right;
5520            }
5521
5522            let buffer_start = excerpt.range.context.start.to_offset(&excerpt.buffer);
5523            let text_anchor =
5524                excerpt.clip_anchor(excerpt.buffer.anchor_at(buffer_start + overshoot, bias));
5525            let anchor = Anchor::in_buffer(excerpt.id, text_anchor);
5526            match diff_base_anchor {
5527                Some(diff_base_anchor) => anchor.with_diff_base_anchor(diff_base_anchor),
5528                None => anchor,
5529            }
5530        } else if excerpt_offset == ExcerptDimension(MultiBufferOffset::ZERO) && bias == Bias::Left
5531        {
5532            Anchor::min()
5533        } else {
5534            Anchor::max()
5535        }
5536    }
5537
5538    /// Wraps the [`text::Anchor`] in a [`multi_buffer::Anchor`] if this multi-buffer is a singleton.
5539    pub fn as_singleton_anchor(&self, text_anchor: text::Anchor) -> Option<Anchor> {
5540        let (excerpt, buffer, _) = self.as_singleton()?;
5541        if text_anchor.buffer_id.is_none_or(|id| id == buffer) {
5542            Some(Anchor::in_buffer(*excerpt, text_anchor))
5543        } else {
5544            None
5545        }
5546    }
5547
5548    /// Returns an anchor for the given excerpt and text anchor,
5549    /// Returns [`None`] if the excerpt_id is no longer valid or the text anchor range is out of excerpt's bounds.
5550    pub fn anchor_range_in_excerpt(
5551        &self,
5552        excerpt_id: ExcerptId,
5553        text_anchor: Range<text::Anchor>,
5554    ) -> Option<Range<Anchor>> {
5555        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5556
5557        Some(
5558            Self::anchor_in_excerpt_(excerpt, text_anchor.start)?
5559                ..Self::anchor_in_excerpt_(excerpt, text_anchor.end)?,
5560        )
5561    }
5562
5563    /// Returns an anchor for the given excerpt and text anchor,
5564    /// Returns [`None`] if the excerpt_id is no longer valid or the text anchor range is out of excerpt's bounds.
5565    pub fn anchor_in_excerpt(
5566        &self,
5567        excerpt_id: ExcerptId,
5568        text_anchor: text::Anchor,
5569    ) -> Option<Anchor> {
5570        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5571        Self::anchor_in_excerpt_(excerpt, text_anchor)
5572    }
5573
5574    /// Same as [`MultiBuffer::anchor_in_excerpt`], but more efficient than calling it multiple times.
5575    pub fn anchors_in_excerpt(
5576        &self,
5577        excerpt_id: ExcerptId,
5578        text_anchors: impl IntoIterator<Item = text::Anchor>,
5579    ) -> Option<impl Iterator<Item = Option<Anchor>>> {
5580        let excerpt = self.excerpt(self.latest_excerpt_id(excerpt_id))?;
5581        Some(
5582            text_anchors
5583                .into_iter()
5584                .map(|text_anchor| Self::anchor_in_excerpt_(excerpt, text_anchor)),
5585        )
5586    }
5587
5588    fn anchor_in_excerpt_(excerpt: &Excerpt, text_anchor: text::Anchor) -> Option<Anchor> {
5589        match text_anchor.buffer_id {
5590            Some(buffer_id) if buffer_id == excerpt.buffer_id => (),
5591            Some(_) => return None,
5592            None if text_anchor.is_max() || text_anchor.is_min() => {
5593                return Some(Anchor::in_buffer(excerpt.id, text_anchor));
5594            }
5595            None => return None,
5596        }
5597
5598        let context = &excerpt.range.context;
5599        if context.start.cmp(&text_anchor, &excerpt.buffer).is_gt()
5600            || context.end.cmp(&text_anchor, &excerpt.buffer).is_lt()
5601        {
5602            return None;
5603        }
5604
5605        Some(Anchor::in_buffer(excerpt.id, text_anchor))
5606    }
5607
5608    pub fn context_range_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<Range<text::Anchor>> {
5609        Some(self.excerpt(excerpt_id)?.range.context.clone())
5610    }
5611
5612    pub fn excerpt_range_for_excerpt(
5613        &self,
5614        excerpt_id: ExcerptId,
5615    ) -> Option<ExcerptRange<text::Anchor>> {
5616        Some(self.excerpt(excerpt_id)?.range.clone())
5617    }
5618
5619    pub fn can_resolve(&self, anchor: &Anchor) -> bool {
5620        if anchor.is_min() || anchor.is_max() {
5621            // todo(lw): should be `!self.is_empty()`
5622            true
5623        } else if let Some(excerpt) = self.excerpt(anchor.excerpt_id) {
5624            excerpt.buffer.can_resolve(&anchor.text_anchor)
5625        } else {
5626            false
5627        }
5628    }
5629
5630    pub fn excerpts(
5631        &self,
5632    ) -> impl Iterator<Item = (ExcerptId, &BufferSnapshot, ExcerptRange<text::Anchor>)> {
5633        self.excerpts
5634            .iter()
5635            .map(|excerpt| (excerpt.id, &excerpt.buffer, excerpt.range.clone()))
5636    }
5637
5638    fn cursor<'a, MBD, BD>(&'a self) -> MultiBufferCursor<'a, MBD, BD>
5639    where
5640        MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
5641        BD: TextDimension + AddAssign<<MBD as Sub>::Output>,
5642    {
5643        let excerpts = self.excerpts.cursor(());
5644        let diff_transforms = self.diff_transforms.cursor(());
5645        MultiBufferCursor {
5646            excerpts,
5647            diff_transforms,
5648            diffs: &self.diffs,
5649            cached_region: None,
5650        }
5651    }
5652
5653    pub fn excerpt_before(&self, excerpt_id: ExcerptId) -> Option<MultiBufferExcerpt<'_>> {
5654        let start_locator = self.excerpt_locator_for_id(excerpt_id);
5655        let mut excerpts = self
5656            .excerpts
5657            .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
5658        excerpts.seek(&Some(start_locator), Bias::Left);
5659        excerpts.prev();
5660
5661        let mut diff_transforms = self
5662            .diff_transforms
5663            .cursor::<DiffTransforms<MultiBufferOffset>>(());
5664        diff_transforms.seek(&excerpts.start().1, Bias::Left);
5665        if diff_transforms.end().excerpt_dimension < excerpts.start().1 {
5666            diff_transforms.next();
5667        }
5668
5669        let excerpt = excerpts.item()?;
5670        Some(MultiBufferExcerpt {
5671            excerpt,
5672            offset: diff_transforms.start().output_dimension.0,
5673            buffer_offset: BufferOffset(excerpt.range.context.start.to_offset(&excerpt.buffer)),
5674            excerpt_offset: excerpts.start().1,
5675            diff_transforms,
5676        })
5677    }
5678
5679    pub fn excerpt_boundaries_in_range<R, T>(
5680        &self,
5681        range: R,
5682    ) -> impl Iterator<Item = ExcerptBoundary> + '_
5683    where
5684        R: RangeBounds<T>,
5685        T: ToOffset,
5686    {
5687        let start_offset;
5688        let start = match range.start_bound() {
5689            Bound::Included(start) => {
5690                start_offset = start.to_offset(self);
5691                Bound::Included(start_offset)
5692            }
5693            Bound::Excluded(_) => {
5694                panic!("not supported")
5695            }
5696            Bound::Unbounded => {
5697                start_offset = MultiBufferOffset::ZERO;
5698                Bound::Unbounded
5699            }
5700        };
5701        let end = match range.end_bound() {
5702            Bound::Included(end) => Bound::Included(end.to_offset(self)),
5703            Bound::Excluded(end) => Bound::Excluded(end.to_offset(self)),
5704            Bound::Unbounded => Bound::Unbounded,
5705        };
5706        let bounds = (start, end);
5707        let mut cursor = self.cursor::<DimensionPair<MultiBufferOffset, Point>, BufferOffset>();
5708        cursor.seek(&DimensionPair {
5709            key: start_offset,
5710            value: None,
5711        });
5712
5713        if cursor
5714            .region()
5715            .is_some_and(|region| bounds.contains(&region.range.start.key))
5716        {
5717            cursor.prev_excerpt();
5718        } else {
5719            cursor.seek_to_start_of_current_excerpt();
5720        }
5721        let mut prev_region = cursor.region();
5722
5723        cursor.next_excerpt();
5724
5725        iter::from_fn(move || {
5726            loop {
5727                if self.singleton {
5728                    return None;
5729                }
5730
5731                let next_region = cursor.region()?;
5732                cursor.next_excerpt();
5733                if !bounds.contains(&next_region.range.start.key) {
5734                    prev_region = Some(next_region);
5735                    continue;
5736                }
5737
5738                let next_region_start = next_region.range.start.value.unwrap();
5739                let next_region_end = if let Some(region) = cursor.region() {
5740                    region.range.start.value.unwrap()
5741                } else {
5742                    self.max_point()
5743                };
5744
5745                let prev = prev_region.as_ref().map(|region| ExcerptInfo {
5746                    id: region.excerpt.id,
5747                    buffer: region.excerpt.buffer.clone(),
5748                    buffer_id: region.excerpt.buffer_id,
5749                    range: region.excerpt.range.clone(),
5750                    end_row: MultiBufferRow(next_region_start.row),
5751                });
5752
5753                let next = ExcerptInfo {
5754                    id: next_region.excerpt.id,
5755                    buffer: next_region.excerpt.buffer.clone(),
5756                    buffer_id: next_region.excerpt.buffer_id,
5757                    range: next_region.excerpt.range.clone(),
5758                    end_row: if next_region.excerpt.has_trailing_newline {
5759                        MultiBufferRow(next_region_end.row - 1)
5760                    } else {
5761                        MultiBufferRow(next_region_end.row)
5762                    },
5763                };
5764
5765                let row = MultiBufferRow(next_region_start.row);
5766
5767                prev_region = Some(next_region);
5768
5769                return Some(ExcerptBoundary { row, prev, next });
5770            }
5771        })
5772    }
5773
5774    pub fn edit_count(&self) -> usize {
5775        self.edit_count
5776    }
5777
5778    pub fn non_text_state_update_count(&self) -> usize {
5779        self.non_text_state_update_count
5780    }
5781
5782    /// Returns the smallest enclosing bracket ranges containing the given range or
5783    /// None if no brackets contain range or the range is not contained in a single
5784    /// excerpt
5785    ///
5786    /// Can optionally pass a range_filter to filter the ranges of brackets to consider
5787    #[ztracing::instrument(skip_all)]
5788    pub fn innermost_enclosing_bracket_ranges<T: ToOffset>(
5789        &self,
5790        range: Range<T>,
5791        range_filter: Option<
5792            &dyn Fn(&BufferSnapshot, Range<BufferOffset>, Range<BufferOffset>) -> bool,
5793        >,
5794    ) -> Option<(Range<MultiBufferOffset>, Range<MultiBufferOffset>)> {
5795        let range = range.start.to_offset(self)..range.end.to_offset(self);
5796        let mut excerpt = self.excerpt_containing(range.clone())?;
5797        let buffer = excerpt.buffer();
5798        let excerpt_buffer_range = excerpt.buffer_range();
5799
5800        // Filter to ranges contained in the excerpt
5801        let range_filter = |open: Range<usize>, close: Range<usize>| -> bool {
5802            excerpt_buffer_range.contains(&BufferOffset(open.start))
5803                && excerpt_buffer_range.contains(&BufferOffset(close.end))
5804                && range_filter.is_none_or(|filter| {
5805                    filter(
5806                        buffer,
5807                        BufferOffset(open.start)..BufferOffset(close.end),
5808                        BufferOffset(close.start)..BufferOffset(close.end),
5809                    )
5810                })
5811        };
5812
5813        let (open, close) = excerpt.buffer().innermost_enclosing_bracket_ranges(
5814            excerpt.map_range_to_buffer(range),
5815            Some(&range_filter),
5816        )?;
5817
5818        Some((
5819            excerpt.map_range_from_buffer(BufferOffset(open.start)..BufferOffset(open.end)),
5820            excerpt.map_range_from_buffer(BufferOffset(close.start)..BufferOffset(close.end)),
5821        ))
5822    }
5823
5824    /// Returns enclosing bracket ranges containing the given range or returns None if the range is
5825    /// not contained in a single excerpt
5826    pub fn enclosing_bracket_ranges<T: ToOffset>(
5827        &self,
5828        range: Range<T>,
5829    ) -> Option<impl Iterator<Item = (Range<MultiBufferOffset>, Range<MultiBufferOffset>)> + '_>
5830    {
5831        let range = range.start.to_offset(self)..range.end.to_offset(self);
5832        let mut excerpt = self.excerpt_containing(range.clone())?;
5833
5834        Some(
5835            excerpt
5836                .buffer()
5837                .enclosing_bracket_ranges(excerpt.map_range_to_buffer(range))
5838                .filter_map(move |pair| {
5839                    let open_range =
5840                        BufferOffset(pair.open_range.start)..BufferOffset(pair.open_range.end);
5841                    let close_range =
5842                        BufferOffset(pair.close_range.start)..BufferOffset(pair.close_range.end);
5843                    if excerpt.contains_buffer_range(open_range.start..close_range.end) {
5844                        Some((
5845                            excerpt.map_range_from_buffer(open_range),
5846                            excerpt.map_range_from_buffer(close_range),
5847                        ))
5848                    } else {
5849                        None
5850                    }
5851                }),
5852        )
5853    }
5854
5855    /// Returns enclosing bracket ranges containing the given range or returns None if the range is
5856    /// not contained in a single excerpt
5857    pub fn text_object_ranges<T: ToOffset>(
5858        &self,
5859        range: Range<T>,
5860        options: TreeSitterOptions,
5861    ) -> impl Iterator<Item = (Range<MultiBufferOffset>, TextObject)> + '_ {
5862        let range = range.start.to_offset(self)..range.end.to_offset(self);
5863        self.excerpt_containing(range.clone())
5864            .map(|mut excerpt| {
5865                excerpt
5866                    .buffer()
5867                    .text_object_ranges(excerpt.map_range_to_buffer(range), options)
5868                    .filter_map(move |(range, text_object)| {
5869                        let range = BufferOffset(range.start)..BufferOffset(range.end);
5870                        if excerpt.contains_buffer_range(range.clone()) {
5871                            Some((excerpt.map_range_from_buffer(range), text_object))
5872                        } else {
5873                            None
5874                        }
5875                    })
5876            })
5877            .into_iter()
5878            .flatten()
5879    }
5880
5881    /// Returns bracket range pairs overlapping the given `range` or returns None if the `range` is
5882    /// not contained in a single excerpt
5883    pub fn bracket_ranges<T: ToOffset>(
5884        &self,
5885        range: Range<T>,
5886    ) -> Option<impl Iterator<Item = (Range<MultiBufferOffset>, Range<MultiBufferOffset>)> + '_>
5887    {
5888        let range = range.start.to_offset(self)..range.end.to_offset(self);
5889        let mut excerpt = self.excerpt_containing(range.clone())?;
5890        Some(
5891            excerpt
5892                .buffer()
5893                .bracket_ranges(excerpt.map_range_to_buffer(range))
5894                .filter_map(move |pair| {
5895                    let open_range =
5896                        BufferOffset(pair.open_range.start)..BufferOffset(pair.open_range.end);
5897                    let close_range =
5898                        BufferOffset(pair.close_range.start)..BufferOffset(pair.close_range.end);
5899                    excerpt
5900                        .contains_buffer_range(open_range.start..close_range.end)
5901                        .then(|| BracketMatch {
5902                            open_range: excerpt.map_range_from_buffer(open_range),
5903                            close_range: excerpt.map_range_from_buffer(close_range),
5904                            color_index: pair.color_index,
5905                            newline_only: pair.newline_only,
5906                            syntax_layer_depth: pair.syntax_layer_depth,
5907                        })
5908                })
5909                .map(BracketMatch::bracket_ranges),
5910        )
5911    }
5912
5913    pub fn redacted_ranges<'a, T: ToOffset>(
5914        &'a self,
5915        range: Range<T>,
5916        redaction_enabled: impl Fn(Option<&Arc<dyn File>>) -> bool + 'a,
5917    ) -> impl Iterator<Item = Range<MultiBufferOffset>> + 'a {
5918        let range = range.start.to_offset(self)..range.end.to_offset(self);
5919        self.lift_buffer_metadata(range, move |buffer, range| {
5920            if redaction_enabled(buffer.file()) {
5921                Some(buffer.redacted_ranges(range).map(|range| (range, ())))
5922            } else {
5923                None
5924            }
5925        })
5926        .map(|(range, _, _)| range)
5927    }
5928
5929    pub fn runnable_ranges(
5930        &self,
5931        range: Range<Anchor>,
5932    ) -> impl Iterator<Item = (Range<MultiBufferOffset>, language::RunnableRange)> + '_ {
5933        let range = range.start.to_offset(self)..range.end.to_offset(self);
5934        self.lift_buffer_metadata(range, move |buffer, range| {
5935            Some(
5936                buffer
5937                    .runnable_ranges(range.clone())
5938                    .filter(move |runnable| {
5939                        runnable.run_range.start >= range.start
5940                            && runnable.run_range.end < range.end
5941                    })
5942                    .map(|runnable| (runnable.run_range.clone(), runnable)),
5943            )
5944        })
5945        .map(|(run_range, runnable, _)| (run_range, runnable))
5946    }
5947
5948    pub fn line_indents(
5949        &self,
5950        start_row: MultiBufferRow,
5951        buffer_filter: impl Fn(&BufferSnapshot) -> bool,
5952    ) -> impl Iterator<Item = (MultiBufferRow, LineIndent, &BufferSnapshot)> {
5953        let max_point = self.max_point();
5954        let mut cursor = self.cursor::<Point, Point>();
5955        cursor.seek(&Point::new(start_row.0, 0));
5956        iter::from_fn(move || {
5957            let mut region = cursor.region()?;
5958            while !buffer_filter(&region.excerpt.buffer) {
5959                cursor.next();
5960                region = cursor.region()?;
5961            }
5962            let overshoot = start_row.0.saturating_sub(region.range.start.row);
5963            let buffer_start_row =
5964                (region.buffer_range.start.row + overshoot).min(region.buffer_range.end.row);
5965
5966            let buffer_end_row = if region.is_main_buffer
5967                && (region.has_trailing_newline || region.range.end == max_point)
5968            {
5969                region.buffer_range.end.row
5970            } else {
5971                region.buffer_range.end.row.saturating_sub(1)
5972            };
5973
5974            let line_indents = region
5975                .buffer
5976                .line_indents_in_row_range(buffer_start_row..buffer_end_row);
5977            cursor.next();
5978            Some(line_indents.map(move |(buffer_row, indent)| {
5979                let row = region.range.start.row + (buffer_row - region.buffer_range.start.row);
5980                (MultiBufferRow(row), indent, &region.excerpt.buffer)
5981            }))
5982        })
5983        .flatten()
5984    }
5985
5986    pub fn reversed_line_indents(
5987        &self,
5988        end_row: MultiBufferRow,
5989        buffer_filter: impl Fn(&BufferSnapshot) -> bool,
5990    ) -> impl Iterator<Item = (MultiBufferRow, LineIndent, &BufferSnapshot)> {
5991        let max_point = self.max_point();
5992        let mut cursor = self.cursor::<Point, Point>();
5993        cursor.seek(&Point::new(end_row.0, 0));
5994        iter::from_fn(move || {
5995            let mut region = cursor.region()?;
5996            while !buffer_filter(&region.excerpt.buffer) {
5997                cursor.prev();
5998                region = cursor.region()?;
5999            }
6000
6001            let buffer_start_row = region.buffer_range.start.row;
6002            let buffer_end_row = if region.is_main_buffer
6003                && (region.has_trailing_newline || region.range.end == max_point)
6004            {
6005                region.buffer_range.end.row + 1
6006            } else {
6007                region.buffer_range.end.row
6008            };
6009
6010            let overshoot = end_row.0 - region.range.start.row;
6011            let buffer_end_row =
6012                (region.buffer_range.start.row + overshoot + 1).min(buffer_end_row);
6013
6014            let line_indents = region
6015                .buffer
6016                .reversed_line_indents_in_row_range(buffer_start_row..buffer_end_row);
6017            cursor.prev();
6018            Some(line_indents.map(move |(buffer_row, indent)| {
6019                let row = region.range.start.row + (buffer_row - region.buffer_range.start.row);
6020                (MultiBufferRow(row), indent, &region.excerpt.buffer)
6021            }))
6022        })
6023        .flatten()
6024    }
6025
6026    pub async fn enclosing_indent(
6027        &self,
6028        mut target_row: MultiBufferRow,
6029    ) -> Option<(Range<MultiBufferRow>, LineIndent)> {
6030        let max_row = MultiBufferRow(self.max_point().row);
6031        if target_row >= max_row {
6032            return None;
6033        }
6034
6035        let mut target_indent = self.line_indent_for_row(target_row);
6036
6037        // If the current row is at the start of an indented block, we want to return this
6038        // block as the enclosing indent.
6039        if !target_indent.is_line_empty() && target_row < max_row {
6040            let next_line_indent = self.line_indent_for_row(MultiBufferRow(target_row.0 + 1));
6041            if !next_line_indent.is_line_empty()
6042                && target_indent.raw_len() < next_line_indent.raw_len()
6043            {
6044                target_indent = next_line_indent;
6045                target_row.0 += 1;
6046            }
6047        }
6048
6049        const SEARCH_ROW_LIMIT: u32 = 25000;
6050        const SEARCH_WHITESPACE_ROW_LIMIT: u32 = 2500;
6051        const YIELD_INTERVAL: u32 = 100;
6052
6053        let mut accessed_row_counter = 0;
6054
6055        // If there is a blank line at the current row, search for the next non indented lines
6056        if target_indent.is_line_empty() {
6057            let start = MultiBufferRow(target_row.0.saturating_sub(SEARCH_WHITESPACE_ROW_LIMIT));
6058            let end =
6059                MultiBufferRow((max_row.0 + 1).min(target_row.0 + SEARCH_WHITESPACE_ROW_LIMIT));
6060
6061            let mut non_empty_line_above = None;
6062            for (row, indent, _) in self.reversed_line_indents(target_row, |_| true) {
6063                if row < start {
6064                    break;
6065                }
6066                accessed_row_counter += 1;
6067                if accessed_row_counter == YIELD_INTERVAL {
6068                    accessed_row_counter = 0;
6069                    yield_now().await;
6070                }
6071                if !indent.is_line_empty() {
6072                    non_empty_line_above = Some((row, indent));
6073                    break;
6074                }
6075            }
6076
6077            let mut non_empty_line_below = None;
6078            for (row, indent, _) in self.line_indents(target_row, |_| true) {
6079                if row > end {
6080                    break;
6081                }
6082                accessed_row_counter += 1;
6083                if accessed_row_counter == YIELD_INTERVAL {
6084                    accessed_row_counter = 0;
6085                    yield_now().await;
6086                }
6087                if !indent.is_line_empty() {
6088                    non_empty_line_below = Some((row, indent));
6089                    break;
6090                }
6091            }
6092
6093            let (row, indent) = match (non_empty_line_above, non_empty_line_below) {
6094                (Some((above_row, above_indent)), Some((below_row, below_indent))) => {
6095                    if above_indent.raw_len() >= below_indent.raw_len() {
6096                        (above_row, above_indent)
6097                    } else {
6098                        (below_row, below_indent)
6099                    }
6100                }
6101                (Some(above), None) => above,
6102                (None, Some(below)) => below,
6103                _ => return None,
6104            };
6105
6106            target_indent = indent;
6107            target_row = row;
6108        }
6109
6110        let start = MultiBufferRow(target_row.0.saturating_sub(SEARCH_ROW_LIMIT));
6111        let end = MultiBufferRow((max_row.0 + 1).min(target_row.0 + SEARCH_ROW_LIMIT));
6112
6113        let mut start_indent = None;
6114        for (row, indent, _) in self.reversed_line_indents(target_row, |_| true) {
6115            if row < start {
6116                break;
6117            }
6118            accessed_row_counter += 1;
6119            if accessed_row_counter == YIELD_INTERVAL {
6120                accessed_row_counter = 0;
6121                yield_now().await;
6122            }
6123            if !indent.is_line_empty() && indent.raw_len() < target_indent.raw_len() {
6124                start_indent = Some((row, indent));
6125                break;
6126            }
6127        }
6128        let (start_row, start_indent_size) = start_indent?;
6129
6130        let mut end_indent = (end, None);
6131        for (row, indent, _) in self.line_indents(target_row, |_| true) {
6132            if row > end {
6133                break;
6134            }
6135            accessed_row_counter += 1;
6136            if accessed_row_counter == YIELD_INTERVAL {
6137                accessed_row_counter = 0;
6138                yield_now().await;
6139            }
6140            if !indent.is_line_empty() && indent.raw_len() < target_indent.raw_len() {
6141                end_indent = (MultiBufferRow(row.0.saturating_sub(1)), Some(indent));
6142                break;
6143            }
6144        }
6145        let (end_row, end_indent_size) = end_indent;
6146
6147        let indent = if let Some(end_indent_size) = end_indent_size {
6148            if start_indent_size.raw_len() > end_indent_size.raw_len() {
6149                start_indent_size
6150            } else {
6151                end_indent_size
6152            }
6153        } else {
6154            start_indent_size
6155        };
6156
6157        Some((start_row..end_row, indent))
6158    }
6159
6160    pub fn indent_guides_in_range<T: ToPoint>(
6161        &self,
6162        range: Range<T>,
6163        ignore_disabled_for_language: bool,
6164        cx: &App,
6165    ) -> impl Iterator<Item = IndentGuide> {
6166        let range = range.start.to_point(self)..range.end.to_point(self);
6167        let start_row = MultiBufferRow(range.start.row);
6168        let end_row = MultiBufferRow(range.end.row);
6169
6170        let mut row_indents = self.line_indents(start_row, |buffer| {
6171            let settings =
6172                language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx);
6173            settings.indent_guides.enabled || ignore_disabled_for_language
6174        });
6175
6176        let mut result = Vec::new();
6177        let mut indent_stack = SmallVec::<[IndentGuide; 8]>::new();
6178
6179        let mut prev_settings = None;
6180        while let Some((first_row, mut line_indent, buffer)) = row_indents.next() {
6181            if first_row > end_row {
6182                break;
6183            }
6184            let current_depth = indent_stack.len() as u32;
6185
6186            // Avoid retrieving the language settings repeatedly for every buffer row.
6187            if let Some((prev_buffer_id, _)) = &prev_settings
6188                && prev_buffer_id != &buffer.remote_id()
6189            {
6190                prev_settings.take();
6191            }
6192            let settings = &prev_settings
6193                .get_or_insert_with(|| {
6194                    (
6195                        buffer.remote_id(),
6196                        language_settings(buffer.language().map(|l| l.name()), buffer.file(), cx),
6197                    )
6198                })
6199                .1;
6200            let tab_size = settings.tab_size.get();
6201
6202            // When encountering empty, continue until found useful line indent
6203            // then add to the indent stack with the depth found
6204            let mut found_indent = false;
6205            let mut last_row = first_row;
6206            if line_indent.is_line_blank() {
6207                while !found_indent {
6208                    let Some((target_row, new_line_indent, _)) = row_indents.next() else {
6209                        break;
6210                    };
6211                    const TRAILING_ROW_SEARCH_LIMIT: u32 = 25;
6212                    if target_row > MultiBufferRow(end_row.0 + TRAILING_ROW_SEARCH_LIMIT) {
6213                        break;
6214                    }
6215
6216                    if new_line_indent.is_line_blank() {
6217                        continue;
6218                    }
6219                    last_row = target_row.min(end_row);
6220                    line_indent = new_line_indent;
6221                    found_indent = true;
6222                    break;
6223                }
6224            } else {
6225                found_indent = true
6226            }
6227
6228            let depth = if found_indent {
6229                line_indent.len(tab_size) / tab_size
6230            } else {
6231                0
6232            };
6233
6234            match depth.cmp(&current_depth) {
6235                cmp::Ordering::Less => {
6236                    for _ in 0..(current_depth - depth) {
6237                        let mut indent = indent_stack.pop().unwrap();
6238                        if last_row != first_row {
6239                            // In this case, we landed on an empty row, had to seek forward,
6240                            // and discovered that the indent we where on is ending.
6241                            // This means that the last display row must
6242                            // be on line that ends this indent range, so we
6243                            // should display the range up to the first non-empty line
6244                            indent.end_row = MultiBufferRow(first_row.0.saturating_sub(1));
6245                        }
6246
6247                        result.push(indent)
6248                    }
6249                }
6250                cmp::Ordering::Greater => {
6251                    for next_depth in current_depth..depth {
6252                        indent_stack.push(IndentGuide {
6253                            buffer_id: buffer.remote_id(),
6254                            start_row: first_row,
6255                            end_row: last_row,
6256                            depth: next_depth,
6257                            tab_size,
6258                            settings: settings.indent_guides.clone(),
6259                        });
6260                    }
6261                }
6262                _ => {}
6263            }
6264
6265            for indent in indent_stack.iter_mut() {
6266                indent.end_row = last_row;
6267            }
6268        }
6269
6270        result.extend(indent_stack);
6271        result.into_iter()
6272    }
6273
6274    pub fn trailing_excerpt_update_count(&self) -> usize {
6275        self.trailing_excerpt_update_count
6276    }
6277
6278    pub fn file_at<T: ToOffset>(&self, point: T) -> Option<&Arc<dyn File>> {
6279        self.point_to_buffer_offset(point)
6280            .and_then(|(buffer, _)| buffer.file())
6281    }
6282
6283    pub fn language_at<T: ToOffset>(&self, offset: T) -> Option<&Arc<Language>> {
6284        self.point_to_buffer_offset(offset)
6285            .and_then(|(buffer, offset)| buffer.language_at(offset))
6286    }
6287
6288    fn language_settings<'a>(&'a self, cx: &'a App) -> Cow<'a, LanguageSettings> {
6289        self.excerpts
6290            .first()
6291            .map(|excerpt| &excerpt.buffer)
6292            .map(|buffer| {
6293                language_settings(
6294                    buffer.language().map(|language| language.name()),
6295                    buffer.file(),
6296                    cx,
6297                )
6298            })
6299            .unwrap_or_else(move || self.language_settings_at(MultiBufferOffset::ZERO, cx))
6300    }
6301
6302    pub fn language_settings_at<'a, T: ToOffset>(
6303        &'a self,
6304        point: T,
6305        cx: &'a App,
6306    ) -> Cow<'a, LanguageSettings> {
6307        let mut language = None;
6308        let mut file = None;
6309        if let Some((buffer, offset)) = self.point_to_buffer_offset(point) {
6310            language = buffer.language_at(offset);
6311            file = buffer.file();
6312        }
6313        language_settings(language.map(|l| l.name()), file, cx)
6314    }
6315
6316    pub fn language_scope_at<T: ToOffset>(&self, point: T) -> Option<LanguageScope> {
6317        self.point_to_buffer_offset(point)
6318            .and_then(|(buffer, offset)| buffer.language_scope_at(offset))
6319    }
6320
6321    pub fn char_classifier_at<T: ToOffset>(&self, point: T) -> CharClassifier {
6322        self.point_to_buffer_offset(point)
6323            .map(|(buffer, offset)| buffer.char_classifier_at(offset))
6324            .unwrap_or_default()
6325    }
6326
6327    pub fn language_indent_size_at<T: ToOffset>(
6328        &self,
6329        position: T,
6330        cx: &App,
6331    ) -> Option<IndentSize> {
6332        let (buffer_snapshot, offset) = self.point_to_buffer_offset(position)?;
6333        Some(buffer_snapshot.language_indent_size_at(offset, cx))
6334    }
6335
6336    pub fn is_dirty(&self) -> bool {
6337        self.is_dirty
6338    }
6339
6340    pub fn has_deleted_file(&self) -> bool {
6341        self.has_deleted_file
6342    }
6343
6344    pub fn has_conflict(&self) -> bool {
6345        self.has_conflict
6346    }
6347
6348    pub fn has_diagnostics(&self) -> bool {
6349        self.excerpts
6350            .iter()
6351            .any(|excerpt| excerpt.buffer.has_diagnostics())
6352    }
6353
6354    pub fn diagnostic_group(
6355        &self,
6356        buffer_id: BufferId,
6357        group_id: usize,
6358    ) -> impl Iterator<Item = DiagnosticEntryRef<'_, Point>> + '_ {
6359        self.lift_buffer_metadata::<Point, _, _>(
6360            Point::zero()..self.max_point(),
6361            move |buffer, range| {
6362                if buffer.remote_id() != buffer_id {
6363                    return None;
6364                };
6365                Some(
6366                    buffer
6367                        .diagnostics_in_range(range, false)
6368                        .filter(move |diagnostic| diagnostic.diagnostic.group_id == group_id)
6369                        .map(move |DiagnosticEntryRef { diagnostic, range }| (range, diagnostic)),
6370                )
6371            },
6372        )
6373        .map(|(range, diagnostic, _)| DiagnosticEntryRef { diagnostic, range })
6374    }
6375
6376    pub fn diagnostics_in_range<'a, MBD>(
6377        &'a self,
6378        range: Range<MBD>,
6379    ) -> impl Iterator<Item = DiagnosticEntryRef<'a, MBD>> + 'a
6380    where
6381        MBD::TextDimension: 'a
6382            + text::ToOffset
6383            + text::FromAnchor
6384            + Sub<Output = MBD::TextDimension>
6385            + fmt::Debug
6386            + ops::Add<Output = MBD::TextDimension>
6387            + ops::AddAssign
6388            + Ord,
6389        MBD: MultiBufferDimension
6390            + Ord
6391            + Sub<Output = MBD::TextDimension>
6392            + ops::Add<MBD::TextDimension, Output = MBD>
6393            + ops::AddAssign<MBD::TextDimension>
6394            + 'a,
6395    {
6396        self.lift_buffer_metadata::<MBD, _, _>(range, move |buffer, buffer_range| {
6397            Some(
6398                buffer
6399                    .diagnostics_in_range(buffer_range.start..buffer_range.end, false)
6400                    .map(|entry| (entry.range, entry.diagnostic)),
6401            )
6402        })
6403        .map(|(range, diagnostic, _)| DiagnosticEntryRef { diagnostic, range })
6404    }
6405
6406    pub fn diagnostics_with_buffer_ids_in_range<'a, MBD>(
6407        &'a self,
6408        range: Range<MBD>,
6409    ) -> impl Iterator<Item = (BufferId, DiagnosticEntryRef<'a, MBD>)> + 'a
6410    where
6411        MBD: MultiBufferDimension
6412            + Ord
6413            + Sub<Output = MBD::TextDimension>
6414            + ops::Add<MBD::TextDimension, Output = MBD>
6415            + ops::AddAssign<MBD::TextDimension>,
6416        MBD::TextDimension: Sub<Output = MBD::TextDimension>
6417            + ops::Add<Output = MBD::TextDimension>
6418            + text::ToOffset
6419            + text::FromAnchor
6420            + AddAssign<MBD::TextDimension>
6421            + Ord,
6422    {
6423        self.lift_buffer_metadata::<MBD, _, _>(range, move |buffer, buffer_range| {
6424            Some(
6425                buffer
6426                    .diagnostics_in_range(buffer_range.start..buffer_range.end, false)
6427                    .map(|entry| (entry.range, entry.diagnostic)),
6428            )
6429        })
6430        .map(|(range, diagnostic, b)| (b.buffer_id, DiagnosticEntryRef { diagnostic, range }))
6431    }
6432
6433    pub fn syntax_ancestor<T: ToOffset>(
6434        &self,
6435        range: Range<T>,
6436    ) -> Option<(tree_sitter::Node<'_>, Range<MultiBufferOffset>)> {
6437        let range = range.start.to_offset(self)..range.end.to_offset(self);
6438        let mut excerpt = self.excerpt_containing(range.clone())?;
6439        let node = excerpt
6440            .buffer()
6441            .syntax_ancestor(excerpt.map_range_to_buffer(range))?;
6442        let node_range = node.byte_range();
6443        let node_range = BufferOffset(node_range.start)..BufferOffset(node_range.end);
6444        if !excerpt.contains_buffer_range(node_range.clone()) {
6445            return None;
6446        };
6447        Some((node, excerpt.map_range_from_buffer(node_range)))
6448    }
6449
6450    pub fn outline(&self, theme: Option<&SyntaxTheme>) -> Option<Outline<Anchor>> {
6451        let (excerpt_id, _, buffer) = self.as_singleton()?;
6452        let outline = buffer.outline(theme);
6453        Some(Outline::new(
6454            outline
6455                .items
6456                .into_iter()
6457                .flat_map(|item| {
6458                    Some(OutlineItem {
6459                        depth: item.depth,
6460                        range: self.anchor_range_in_excerpt(*excerpt_id, item.range)?,
6461                        source_range_for_text: self
6462                            .anchor_range_in_excerpt(*excerpt_id, item.source_range_for_text)?,
6463                        text: item.text,
6464                        highlight_ranges: item.highlight_ranges,
6465                        name_ranges: item.name_ranges,
6466                        body_range: item.body_range.and_then(|body_range| {
6467                            self.anchor_range_in_excerpt(*excerpt_id, body_range)
6468                        }),
6469                        annotation_range: item.annotation_range.and_then(|annotation_range| {
6470                            self.anchor_range_in_excerpt(*excerpt_id, annotation_range)
6471                        }),
6472                    })
6473                })
6474                .collect(),
6475        ))
6476    }
6477
6478    pub fn symbols_containing<T: ToOffset>(
6479        &self,
6480        offset: T,
6481        theme: Option<&SyntaxTheme>,
6482    ) -> Option<(BufferId, Vec<OutlineItem<Anchor>>)> {
6483        let anchor = self.anchor_before(offset);
6484        let excerpt @ &Excerpt {
6485            id: excerpt_id,
6486            buffer_id,
6487            ref buffer,
6488            ..
6489        } = self.excerpt(anchor.excerpt_id)?;
6490        if cfg!(debug_assertions) {
6491            match anchor.text_anchor.buffer_id {
6492                // we clearly are hitting this according to sentry, but in what situations can this occur?
6493                Some(anchor_buffer_id) => {
6494                    assert_eq!(
6495                        anchor_buffer_id, buffer_id,
6496                        "anchor {anchor:?} does not match with resolved excerpt {excerpt:?}"
6497                    )
6498                }
6499                None => assert!(anchor.is_max()),
6500            }
6501        };
6502        Some((
6503            buffer_id,
6504            buffer
6505                .symbols_containing(anchor.text_anchor, theme)
6506                .into_iter()
6507                .flat_map(|item| {
6508                    Some(OutlineItem {
6509                        depth: item.depth,
6510                        source_range_for_text: Anchor::range_in_buffer(
6511                            excerpt_id,
6512                            item.source_range_for_text,
6513                        ),
6514                        range: Anchor::range_in_buffer(excerpt_id, item.range),
6515                        text: item.text,
6516                        highlight_ranges: item.highlight_ranges,
6517                        name_ranges: item.name_ranges,
6518                        body_range: item
6519                            .body_range
6520                            .map(|body_range| Anchor::range_in_buffer(excerpt_id, body_range)),
6521                        annotation_range: item
6522                            .annotation_range
6523                            .map(|body_range| Anchor::range_in_buffer(excerpt_id, body_range)),
6524                    })
6525                })
6526                .collect(),
6527        ))
6528    }
6529
6530    fn excerpt_locator_for_id(&self, id: ExcerptId) -> &Locator {
6531        if id == ExcerptId::min() {
6532            Locator::min_ref()
6533        } else if id == ExcerptId::max() {
6534            Locator::max_ref()
6535        } else {
6536            let (_, _, item) = self.excerpt_ids.find::<ExcerptId, _>((), &id, Bias::Left);
6537            if let Some(entry) = item
6538                && entry.id == id
6539            {
6540                return &entry.locator;
6541            }
6542            panic!("invalid excerpt id {id:?}")
6543        }
6544    }
6545
6546    /// Returns the locators referenced by the given excerpt IDs, sorted by locator.
6547    fn excerpt_locators_for_ids(
6548        &self,
6549        ids: impl IntoIterator<Item = ExcerptId>,
6550    ) -> SmallVec<[Locator; 1]> {
6551        let mut sorted_ids = ids.into_iter().collect::<SmallVec<[_; 1]>>();
6552        sorted_ids.sort_unstable();
6553        sorted_ids.dedup();
6554        let mut locators = SmallVec::new();
6555
6556        while sorted_ids.last() == Some(&ExcerptId::max()) {
6557            sorted_ids.pop();
6558            locators.push(Locator::max());
6559        }
6560
6561        let mut sorted_ids = sorted_ids.into_iter().peekable();
6562        locators.extend(
6563            sorted_ids
6564                .peeking_take_while(|excerpt| *excerpt == ExcerptId::min())
6565                .map(|_| Locator::min()),
6566        );
6567
6568        let mut cursor = self.excerpt_ids.cursor::<ExcerptId>(());
6569        for id in sorted_ids {
6570            if cursor.seek_forward(&id, Bias::Left) {
6571                locators.push(cursor.item().unwrap().locator.clone());
6572            } else {
6573                panic!("invalid excerpt id {:?}", id);
6574            }
6575        }
6576
6577        locators.sort_unstable();
6578        locators
6579    }
6580
6581    pub fn buffer_id_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<BufferId> {
6582        Some(self.excerpt(excerpt_id)?.buffer_id)
6583    }
6584
6585    pub fn buffer_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<&BufferSnapshot> {
6586        Some(&self.excerpt(excerpt_id)?.buffer)
6587    }
6588
6589    pub fn range_for_excerpt(&self, excerpt_id: ExcerptId) -> Option<Range<Point>> {
6590        let mut cursor = self
6591            .excerpts
6592            .cursor::<Dimensions<Option<&Locator>, ExcerptPoint>>(());
6593        let locator = self.excerpt_locator_for_id(excerpt_id);
6594        let mut sought_exact = cursor.seek(&Some(locator), Bias::Left);
6595        if cursor.item().is_none() && excerpt_id == ExcerptId::max() {
6596            sought_exact = true;
6597            cursor.prev();
6598        } else if excerpt_id == ExcerptId::min() {
6599            sought_exact = true;
6600        }
6601        if sought_exact {
6602            let start = cursor.start().1;
6603            let end = cursor.end().1;
6604            let mut diff_transforms = self
6605                .diff_transforms
6606                .cursor::<Dimensions<ExcerptPoint, OutputDimension<Point>>>(());
6607            diff_transforms.seek(&start, Bias::Left);
6608            let overshoot = start - diff_transforms.start().0;
6609            let start = diff_transforms.start().1 + overshoot;
6610            diff_transforms.seek(&end, Bias::Right);
6611            let overshoot = end - diff_transforms.start().0;
6612            let end = diff_transforms.start().1 + overshoot;
6613            Some(start.0..end.0)
6614        } else {
6615            None
6616        }
6617    }
6618
6619    /// Returns the excerpt for the given id. The returned excerpt is guaranteed
6620    /// to have the latest excerpt id for the one passed in and will also remap
6621    /// `ExcerptId::max()` to the corresponding excertp ID.
6622    ///
6623    /// Callers of this function should generally use the resulting excerpt's `id` field
6624    /// afterwards.
6625    fn excerpt(&self, excerpt_id: ExcerptId) -> Option<&Excerpt> {
6626        let excerpt_id = self.latest_excerpt_id(excerpt_id);
6627        let mut cursor = self.excerpts.cursor::<Option<&Locator>>(());
6628        let locator = self.excerpt_locator_for_id(excerpt_id);
6629        cursor.seek(&Some(locator), Bias::Left);
6630        if let Some(excerpt) = cursor.item()
6631            && excerpt.id == excerpt_id
6632        {
6633            return Some(excerpt);
6634        } else if cursor.item().is_none() && excerpt_id == ExcerptId::max() {
6635            cursor.prev();
6636            return cursor.item();
6637        }
6638        None
6639    }
6640
6641    /// Returns the excerpt containing range and its offset start within the multibuffer or none if `range` spans multiple excerpts
6642    pub fn excerpt_containing<T: ToOffset>(
6643        &self,
6644        range: Range<T>,
6645    ) -> Option<MultiBufferExcerpt<'_>> {
6646        let range = range.start.to_offset(self)..range.end.to_offset(self);
6647        let mut cursor = self.cursor::<MultiBufferOffset, BufferOffset>();
6648        cursor.seek(&range.start);
6649
6650        let start_excerpt = cursor.excerpt()?;
6651        if range.end != range.start {
6652            cursor.seek_forward(&range.end);
6653            if cursor.excerpt()?.id != start_excerpt.id {
6654                return None;
6655            }
6656        }
6657
6658        cursor.seek_to_start_of_current_excerpt();
6659        let region = cursor.region()?;
6660        let offset = region.range.start;
6661        let buffer_offset = start_excerpt.buffer_start_offset();
6662        let excerpt_offset = *cursor.excerpts.start();
6663        Some(MultiBufferExcerpt {
6664            diff_transforms: cursor.diff_transforms,
6665            excerpt: start_excerpt,
6666            offset,
6667            buffer_offset,
6668            excerpt_offset,
6669        })
6670    }
6671
6672    pub fn buffer_id_for_anchor(&self, anchor: Anchor) -> Option<BufferId> {
6673        if let Some(id) = anchor.text_anchor.buffer_id {
6674            return Some(id);
6675        }
6676        let excerpt = self.excerpt_containing(anchor..anchor)?;
6677        Some(excerpt.buffer_id())
6678    }
6679
6680    pub fn selections_in_range<'a>(
6681        &'a self,
6682        range: &'a Range<Anchor>,
6683        include_local: bool,
6684    ) -> impl 'a + Iterator<Item = (ReplicaId, bool, CursorShape, Selection<Anchor>)> {
6685        let mut cursor = self.excerpts.cursor::<ExcerptSummary>(());
6686        let start_locator = self.excerpt_locator_for_id(range.start.excerpt_id);
6687        let end_locator = self.excerpt_locator_for_id(range.end.excerpt_id);
6688        cursor.seek(start_locator, Bias::Left);
6689        cursor
6690            .take_while(move |excerpt| excerpt.locator <= *end_locator)
6691            .flat_map(move |excerpt| {
6692                let mut query_range = excerpt.range.context.start..excerpt.range.context.end;
6693                if excerpt.id == range.start.excerpt_id {
6694                    query_range.start = range.start.text_anchor;
6695                }
6696                if excerpt.id == range.end.excerpt_id {
6697                    query_range.end = range.end.text_anchor;
6698                }
6699
6700                excerpt
6701                    .buffer
6702                    .selections_in_range(query_range, include_local)
6703                    .flat_map(move |(replica_id, line_mode, cursor_shape, selections)| {
6704                        selections.map(move |selection| {
6705                            let mut start = Anchor::in_buffer(excerpt.id, selection.start);
6706                            let mut end = Anchor::in_buffer(excerpt.id, selection.end);
6707                            if range.start.cmp(&start, self).is_gt() {
6708                                start = range.start;
6709                            }
6710                            if range.end.cmp(&end, self).is_lt() {
6711                                end = range.end;
6712                            }
6713
6714                            (
6715                                replica_id,
6716                                line_mode,
6717                                cursor_shape,
6718                                Selection {
6719                                    id: selection.id,
6720                                    start,
6721                                    end,
6722                                    reversed: selection.reversed,
6723                                    goal: selection.goal,
6724                                },
6725                            )
6726                        })
6727                    })
6728            })
6729    }
6730
6731    pub fn show_headers(&self) -> bool {
6732        self.show_headers
6733    }
6734
6735    pub fn diff_for_buffer_id(&self, buffer_id: BufferId) -> Option<&BufferDiffSnapshot> {
6736        self.diffs.get(&buffer_id).map(|diff| &diff.diff)
6737    }
6738
6739    /// Visually annotates a position or range with the `Debug` representation of a value. The
6740    /// callsite of this function is used as a key - previous annotations will be removed.
6741    #[cfg(debug_assertions)]
6742    #[track_caller]
6743    pub fn debug<V, R>(&self, ranges: &R, value: V)
6744    where
6745        R: debug::ToMultiBufferDebugRanges,
6746        V: std::fmt::Debug,
6747    {
6748        self.debug_with_key(std::panic::Location::caller(), ranges, value);
6749    }
6750
6751    /// Visually annotates a position or range with the `Debug` representation of a value. Previous
6752    /// debug annotations with the same key will be removed. The key is also used to determine the
6753    /// annotation's color.
6754    #[cfg(debug_assertions)]
6755    #[track_caller]
6756    pub fn debug_with_key<K, R, V>(&self, key: &K, ranges: &R, value: V)
6757    where
6758        K: std::hash::Hash + 'static,
6759        R: debug::ToMultiBufferDebugRanges,
6760        V: std::fmt::Debug,
6761    {
6762        let text_ranges = ranges
6763            .to_multi_buffer_debug_ranges(self)
6764            .into_iter()
6765            .flat_map(|range| {
6766                self.range_to_buffer_ranges(range).into_iter().map(
6767                    |(buffer, range, _excerpt_id)| {
6768                        buffer.anchor_after(range.start)..buffer.anchor_before(range.end)
6769                    },
6770                )
6771            })
6772            .collect();
6773        text::debug::GlobalDebugRanges::with_locked(|debug_ranges| {
6774            debug_ranges.insert(key, text_ranges, format!("{value:?}").into())
6775        });
6776    }
6777
6778    fn excerpt_edits_for_diff_change(
6779        &self,
6780        buffer_state: &BufferState,
6781        diff_change_range: Range<usize>,
6782    ) -> Vec<Edit<ExcerptDimension<MultiBufferOffset>>> {
6783        let mut excerpt_edits = Vec::new();
6784        for locator in &buffer_state.excerpts {
6785            let mut cursor = self
6786                .excerpts
6787                .cursor::<Dimensions<Option<&Locator>, ExcerptOffset>>(());
6788            cursor.seek_forward(&Some(locator), Bias::Left);
6789            if let Some(excerpt) = cursor.item()
6790                && excerpt.locator == *locator
6791            {
6792                let excerpt_buffer_range = excerpt.range.context.to_offset(&excerpt.buffer);
6793                if diff_change_range.end < excerpt_buffer_range.start
6794                    || diff_change_range.start > excerpt_buffer_range.end
6795                {
6796                    continue;
6797                }
6798                let excerpt_start = cursor.start().1;
6799                let excerpt_len = excerpt.text_summary.len;
6800                let diff_change_start_in_excerpt = diff_change_range
6801                    .start
6802                    .saturating_sub(excerpt_buffer_range.start);
6803                let diff_change_end_in_excerpt = diff_change_range
6804                    .end
6805                    .saturating_sub(excerpt_buffer_range.start);
6806                let edit_start = excerpt_start + diff_change_start_in_excerpt.min(excerpt_len);
6807                let edit_end = excerpt_start + diff_change_end_in_excerpt.min(excerpt_len);
6808                excerpt_edits.push(Edit {
6809                    old: edit_start..edit_end,
6810                    new: edit_start..edit_end,
6811                });
6812            }
6813        }
6814        excerpt_edits
6815    }
6816}
6817
6818#[cfg(any(test, feature = "test-support"))]
6819impl MultiBufferSnapshot {
6820    pub fn random_byte_range(
6821        &self,
6822        start_offset: MultiBufferOffset,
6823        rng: &mut impl rand::Rng,
6824    ) -> Range<MultiBufferOffset> {
6825        let end = self.clip_offset(rng.random_range(start_offset..=self.len()), Bias::Right);
6826        let start = self.clip_offset(rng.random_range(start_offset..=end), Bias::Right);
6827        start..end
6828    }
6829
6830    #[cfg(any(test, feature = "test-support"))]
6831    fn check_invariants(&self) {
6832        let excerpts = self.excerpts.items(());
6833        let excerpt_ids = self.excerpt_ids.items(());
6834
6835        for (ix, excerpt) in excerpts.iter().enumerate() {
6836            if ix == 0 {
6837                if excerpt.locator <= Locator::min() {
6838                    panic!("invalid first excerpt locator {:?}", excerpt.locator);
6839                }
6840            } else if excerpt.locator <= excerpts[ix - 1].locator {
6841                panic!("excerpts are out-of-order: {:?}", excerpts);
6842            }
6843        }
6844
6845        for (ix, entry) in excerpt_ids.iter().enumerate() {
6846            if ix == 0 {
6847                if entry.id.cmp(&ExcerptId::min(), self).is_le() {
6848                    panic!("invalid first excerpt id {:?}", entry.id);
6849                }
6850            } else if entry.id <= excerpt_ids[ix - 1].id {
6851                panic!("excerpt ids are out-of-order: {:?}", excerpt_ids);
6852            }
6853        }
6854
6855        if self.diff_transforms.summary().input != self.excerpts.summary().text {
6856            panic!(
6857                "incorrect input summary. expected {:?}, got {:?}. transforms: {:+?}",
6858                self.excerpts.summary().text,
6859                self.diff_transforms.summary().input,
6860                self.diff_transforms.items(()),
6861            );
6862        }
6863
6864        let mut prev_transform: Option<&DiffTransform> = None;
6865        for item in self.diff_transforms.iter() {
6866            if let DiffTransform::BufferContent {
6867                summary,
6868                inserted_hunk_info,
6869            } = item
6870            {
6871                if let Some(DiffTransform::BufferContent {
6872                    inserted_hunk_info: prev_inserted_hunk_info,
6873                    ..
6874                }) = prev_transform
6875                    && *inserted_hunk_info == *prev_inserted_hunk_info
6876                {
6877                    panic!(
6878                        "multiple adjacent buffer content transforms with is_inserted_hunk = {inserted_hunk_info:?}. transforms: {:+?}",
6879                        self.diff_transforms.items(())
6880                    );
6881                }
6882                if summary.len == MultiBufferOffset(0) && !self.is_empty() {
6883                    panic!("empty buffer content transform");
6884                }
6885            }
6886            prev_transform = Some(item);
6887        }
6888    }
6889}
6890
6891impl<'a, MBD, BD> MultiBufferCursor<'a, MBD, BD>
6892where
6893    MBD: MultiBufferDimension + Ord + Sub + ops::AddAssign<<MBD as Sub>::Output>,
6894    BD: TextDimension + AddAssign<<MBD as Sub>::Output>,
6895{
6896    #[instrument(skip_all)]
6897    fn seek(&mut self, position: &MBD) {
6898        let position = OutputDimension(*position);
6899        self.cached_region.take();
6900        self.diff_transforms.seek(&position, Bias::Right);
6901        if self.diff_transforms.item().is_none()
6902            && self.diff_transforms.start().output_dimension == position
6903        {
6904            self.diff_transforms.prev();
6905        }
6906
6907        let mut excerpt_position = self.diff_transforms.start().excerpt_dimension;
6908        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
6909            let overshoot = position - self.diff_transforms.start().output_dimension;
6910            excerpt_position += overshoot;
6911        }
6912
6913        self.excerpts.seek(&excerpt_position, Bias::Right);
6914        if self.excerpts.item().is_none() && excerpt_position == *self.excerpts.start() {
6915            self.excerpts.prev();
6916        }
6917    }
6918
6919    fn seek_forward(&mut self, position: &MBD) {
6920        let position = OutputDimension(*position);
6921        self.cached_region.take();
6922        self.diff_transforms.seek_forward(&position, Bias::Right);
6923        if self.diff_transforms.item().is_none()
6924            && self.diff_transforms.start().output_dimension == position
6925        {
6926            self.diff_transforms.prev();
6927        }
6928
6929        let overshoot = position - self.diff_transforms.start().output_dimension;
6930        let mut excerpt_position = self.diff_transforms.start().excerpt_dimension;
6931        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
6932            excerpt_position += overshoot;
6933        }
6934
6935        self.excerpts.seek_forward(&excerpt_position, Bias::Right);
6936        if self.excerpts.item().is_none() && excerpt_position == *self.excerpts.start() {
6937            self.excerpts.prev();
6938        }
6939    }
6940
6941    fn next_excerpt(&mut self) {
6942        self.excerpts.next();
6943        self.seek_to_start_of_current_excerpt();
6944    }
6945
6946    fn prev_excerpt(&mut self) {
6947        self.excerpts.prev();
6948        self.seek_to_start_of_current_excerpt();
6949    }
6950
6951    fn seek_to_start_of_current_excerpt(&mut self) {
6952        self.cached_region.take();
6953        self.diff_transforms.seek(self.excerpts.start(), Bias::Left);
6954        if self.diff_transforms.end().excerpt_dimension == *self.excerpts.start()
6955            && self.diff_transforms.start().excerpt_dimension < *self.excerpts.start()
6956            && self.diff_transforms.next_item().is_some()
6957        {
6958            self.diff_transforms.next();
6959        }
6960    }
6961
6962    fn next(&mut self) {
6963        self.cached_region.take();
6964        match self
6965            .diff_transforms
6966            .end()
6967            .excerpt_dimension
6968            .cmp(&self.excerpts.end())
6969        {
6970            cmp::Ordering::Less => self.diff_transforms.next(),
6971            cmp::Ordering::Greater => self.excerpts.next(),
6972            cmp::Ordering::Equal => {
6973                self.diff_transforms.next();
6974                if self.diff_transforms.end().excerpt_dimension > self.excerpts.end()
6975                    || self.diff_transforms.item().is_none()
6976                {
6977                    self.excerpts.next();
6978                } else if let Some(DiffTransform::DeletedHunk { hunk_info, .. }) =
6979                    self.diff_transforms.item()
6980                    && self
6981                        .excerpts
6982                        .item()
6983                        .is_some_and(|excerpt| excerpt.id != hunk_info.excerpt_id)
6984                {
6985                    self.excerpts.next();
6986                }
6987            }
6988        }
6989    }
6990
6991    fn prev(&mut self) {
6992        self.cached_region.take();
6993        match self
6994            .diff_transforms
6995            .start()
6996            .excerpt_dimension
6997            .cmp(self.excerpts.start())
6998        {
6999            cmp::Ordering::Less => self.excerpts.prev(),
7000            cmp::Ordering::Greater => self.diff_transforms.prev(),
7001            cmp::Ordering::Equal => {
7002                self.diff_transforms.prev();
7003                if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start()
7004                    || self.diff_transforms.item().is_none()
7005                {
7006                    self.excerpts.prev();
7007                }
7008            }
7009        }
7010    }
7011
7012    fn region(&mut self) -> Option<MultiBufferRegion<'a, MBD, BD>> {
7013        if self.cached_region.is_none() {
7014            self.cached_region = self.build_region();
7015        }
7016        self.cached_region.clone()
7017    }
7018
7019    fn is_at_start_of_excerpt(&mut self) -> bool {
7020        if self.diff_transforms.start().excerpt_dimension > *self.excerpts.start() {
7021            return false;
7022        } else if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start() {
7023            return true;
7024        }
7025
7026        self.diff_transforms.prev();
7027        let prev_transform = self.diff_transforms.item();
7028        self.diff_transforms.next();
7029
7030        prev_transform.is_none_or(|next_transform| {
7031            matches!(next_transform, DiffTransform::BufferContent { .. })
7032        })
7033    }
7034
7035    fn is_at_end_of_excerpt(&mut self) -> bool {
7036        if self.diff_transforms.end().excerpt_dimension < self.excerpts.end() {
7037            return false;
7038        } else if self.diff_transforms.end().excerpt_dimension > self.excerpts.end()
7039            || self.diff_transforms.item().is_none()
7040        {
7041            return true;
7042        }
7043
7044        let next_transform = self.diff_transforms.next_item();
7045        next_transform.is_none_or(|next_transform| match next_transform {
7046            DiffTransform::BufferContent { .. } => true,
7047            DiffTransform::DeletedHunk { hunk_info, .. } => self
7048                .excerpts
7049                .item()
7050                .is_some_and(|excerpt| excerpt.id != hunk_info.excerpt_id),
7051        })
7052    }
7053
7054    fn main_buffer_position(&self) -> Option<BD> {
7055        let excerpt = self.excerpts.item()?;
7056        let buffer = &excerpt.buffer;
7057        let buffer_context_start = excerpt.range.context.start.summary::<BD>(buffer);
7058        let mut buffer_start = buffer_context_start;
7059        let overshoot = self.diff_transforms.end().excerpt_dimension - *self.excerpts.start();
7060        buffer_start += overshoot;
7061        Some(buffer_start)
7062    }
7063
7064    fn build_region(&self) -> Option<MultiBufferRegion<'a, MBD, BD>> {
7065        let excerpt = self.excerpts.item()?;
7066        match self.diff_transforms.item()? {
7067            DiffTransform::DeletedHunk {
7068                buffer_id,
7069                base_text_byte_range,
7070                has_trailing_newline,
7071                hunk_info,
7072                ..
7073            } => {
7074                let diff = self.diffs.get(buffer_id)?;
7075                let buffer = diff.base_text();
7076                let mut rope_cursor = buffer.as_rope().cursor(0);
7077                let buffer_start = rope_cursor.summary::<BD>(base_text_byte_range.start);
7078                let buffer_range_len = rope_cursor.summary::<BD>(base_text_byte_range.end);
7079                let mut buffer_end = buffer_start;
7080                TextDimension::add_assign(&mut buffer_end, &buffer_range_len);
7081                let start = self.diff_transforms.start().output_dimension.0;
7082                let end = self.diff_transforms.end().output_dimension.0;
7083                Some(MultiBufferRegion {
7084                    buffer,
7085                    excerpt,
7086                    has_trailing_newline: *has_trailing_newline,
7087                    is_main_buffer: false,
7088                    diff_hunk_status: Some(DiffHunkStatus::deleted(
7089                        hunk_info.hunk_secondary_status,
7090                    )),
7091                    buffer_range: buffer_start..buffer_end,
7092                    range: start..end,
7093                })
7094            }
7095            DiffTransform::BufferContent {
7096                inserted_hunk_info, ..
7097            } => {
7098                let buffer = &excerpt.buffer;
7099                let buffer_context_start = excerpt.range.context.start.summary::<BD>(buffer);
7100
7101                let mut start = self.diff_transforms.start().output_dimension.0;
7102                let mut buffer_start = buffer_context_start;
7103                if self.diff_transforms.start().excerpt_dimension < *self.excerpts.start() {
7104                    let overshoot =
7105                        *self.excerpts.start() - self.diff_transforms.start().excerpt_dimension;
7106                    start += overshoot;
7107                } else {
7108                    let overshoot =
7109                        self.diff_transforms.start().excerpt_dimension - *self.excerpts.start();
7110                    buffer_start += overshoot;
7111                }
7112
7113                let mut end;
7114                let mut buffer_end;
7115                let has_trailing_newline;
7116                if self.diff_transforms.end().excerpt_dimension < self.excerpts.end() {
7117                    let overshoot =
7118                        self.diff_transforms.end().excerpt_dimension - *self.excerpts.start();
7119                    end = self.diff_transforms.end().output_dimension.0;
7120                    buffer_end = buffer_context_start;
7121                    buffer_end += overshoot;
7122                    has_trailing_newline = false;
7123                } else {
7124                    let overshoot =
7125                        self.excerpts.end() - self.diff_transforms.start().excerpt_dimension;
7126                    end = self.diff_transforms.start().output_dimension.0;
7127                    end += overshoot;
7128                    buffer_end = excerpt.range.context.end.summary::<BD>(buffer);
7129                    has_trailing_newline = excerpt.has_trailing_newline;
7130                };
7131
7132                let diff_hunk_status = inserted_hunk_info.map(|info| {
7133                    if info.is_logically_deleted {
7134                        DiffHunkStatus::deleted(info.hunk_secondary_status)
7135                    } else {
7136                        DiffHunkStatus::added(info.hunk_secondary_status)
7137                    }
7138                });
7139
7140                Some(MultiBufferRegion {
7141                    buffer,
7142                    excerpt,
7143                    has_trailing_newline,
7144                    is_main_buffer: true,
7145                    diff_hunk_status,
7146                    buffer_range: buffer_start..buffer_end,
7147                    range: start..end,
7148                })
7149            }
7150        }
7151    }
7152
7153    fn excerpt(&self) -> Option<&'a Excerpt> {
7154        self.excerpts.item()
7155    }
7156}
7157
7158impl Excerpt {
7159    fn new(
7160        id: ExcerptId,
7161        locator: Locator,
7162        buffer_id: BufferId,
7163        buffer: BufferSnapshot,
7164        range: ExcerptRange<text::Anchor>,
7165        has_trailing_newline: bool,
7166    ) -> Self {
7167        Excerpt {
7168            id,
7169            locator,
7170            max_buffer_row: range.context.end.to_point(&buffer).row,
7171            text_summary: buffer
7172                .text_summary_for_range::<TextSummary, _>(range.context.to_offset(&buffer)),
7173            buffer_id,
7174            buffer,
7175            range,
7176            has_trailing_newline,
7177        }
7178    }
7179
7180    fn chunks_in_range(&self, range: Range<usize>, language_aware: bool) -> ExcerptChunks<'_> {
7181        let content_start = self.range.context.start.to_offset(&self.buffer);
7182        let chunks_start = content_start + range.start;
7183        let chunks_end = content_start + cmp::min(range.end, self.text_summary.len);
7184
7185        let has_footer = self.has_trailing_newline
7186            && range.start <= self.text_summary.len
7187            && range.end > self.text_summary.len;
7188
7189        let content_chunks = self.buffer.chunks(chunks_start..chunks_end, language_aware);
7190
7191        ExcerptChunks {
7192            excerpt_id: self.id,
7193            content_chunks,
7194            has_footer,
7195        }
7196    }
7197
7198    fn seek_chunks(&self, excerpt_chunks: &mut ExcerptChunks, range: Range<usize>) {
7199        let content_start = self.range.context.start.to_offset(&self.buffer);
7200        let chunks_start = content_start + range.start;
7201        let chunks_end = content_start + cmp::min(range.end, self.text_summary.len);
7202        excerpt_chunks.content_chunks.seek(chunks_start..chunks_end);
7203        excerpt_chunks.has_footer = self.has_trailing_newline
7204            && range.start <= self.text_summary.len
7205            && range.end > self.text_summary.len;
7206    }
7207
7208    fn clip_anchor(&self, text_anchor: text::Anchor) -> text::Anchor {
7209        if text_anchor
7210            .cmp(&self.range.context.start, &self.buffer)
7211            .is_lt()
7212        {
7213            self.range.context.start
7214        } else if text_anchor
7215            .cmp(&self.range.context.end, &self.buffer)
7216            .is_gt()
7217        {
7218            self.range.context.end
7219        } else {
7220            text_anchor
7221        }
7222    }
7223
7224    fn contains(&self, anchor: &Anchor) -> bool {
7225        (anchor.text_anchor.buffer_id == None
7226            || anchor.text_anchor.buffer_id == Some(self.buffer_id))
7227            && self
7228                .range
7229                .context
7230                .start
7231                .cmp(&anchor.text_anchor, &self.buffer)
7232                .is_le()
7233            && self
7234                .range
7235                .context
7236                .end
7237                .cmp(&anchor.text_anchor, &self.buffer)
7238                .is_ge()
7239    }
7240
7241    /// The [`Excerpt`]'s start offset in its [`Buffer`]
7242    fn buffer_start_offset(&self) -> BufferOffset {
7243        BufferOffset(self.range.context.start.to_offset(&self.buffer))
7244    }
7245
7246    /// The [`Excerpt`]'s end offset in its [`Buffer`]
7247    fn buffer_end_offset(&self) -> BufferOffset {
7248        self.buffer_start_offset() + self.text_summary.len
7249    }
7250}
7251
7252impl<'a> MultiBufferExcerpt<'a> {
7253    pub fn id(&self) -> ExcerptId {
7254        self.excerpt.id
7255    }
7256
7257    pub fn buffer_id(&self) -> BufferId {
7258        self.excerpt.buffer_id
7259    }
7260
7261    pub fn start_anchor(&self) -> Anchor {
7262        Anchor::in_buffer(self.excerpt.id, self.excerpt.range.context.start)
7263    }
7264
7265    pub fn end_anchor(&self) -> Anchor {
7266        Anchor::in_buffer(self.excerpt.id, self.excerpt.range.context.end)
7267    }
7268
7269    pub fn buffer(&self) -> &'a BufferSnapshot {
7270        &self.excerpt.buffer
7271    }
7272
7273    pub fn buffer_range(&self) -> Range<BufferOffset> {
7274        self.buffer_offset
7275            ..BufferOffset(
7276                self.excerpt
7277                    .range
7278                    .context
7279                    .end
7280                    .to_offset(&self.excerpt.buffer.text),
7281            )
7282    }
7283
7284    pub fn start_offset(&self) -> MultiBufferOffset {
7285        self.offset
7286    }
7287
7288    /// Maps an offset within the [`MultiBuffer`] to an offset within the [`Buffer`]
7289    pub fn map_offset_to_buffer(&mut self, offset: MultiBufferOffset) -> BufferOffset {
7290        self.map_range_to_buffer(offset..offset).start
7291    }
7292
7293    /// Maps a range within the [`MultiBuffer`] to a range within the [`Buffer`]
7294    pub fn map_range_to_buffer(&mut self, range: Range<MultiBufferOffset>) -> Range<BufferOffset> {
7295        self.diff_transforms
7296            .seek(&OutputDimension(range.start), Bias::Right);
7297        let start = self.map_offset_to_buffer_internal(range.start);
7298        let end = if range.end > range.start {
7299            self.diff_transforms
7300                .seek_forward(&OutputDimension(range.end), Bias::Right);
7301            self.map_offset_to_buffer_internal(range.end)
7302        } else {
7303            start
7304        };
7305        start..end
7306    }
7307
7308    fn map_offset_to_buffer_internal(&self, offset: MultiBufferOffset) -> BufferOffset {
7309        let mut excerpt_offset = self.diff_transforms.start().excerpt_dimension;
7310        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7311            excerpt_offset += offset - self.diff_transforms.start().output_dimension.0;
7312        };
7313        let offset_in_excerpt = excerpt_offset.saturating_sub(self.excerpt_offset);
7314        self.buffer_offset + offset_in_excerpt
7315    }
7316
7317    /// Map an offset within the [`Buffer`] to an offset within the [`MultiBuffer`]
7318    pub fn map_offset_from_buffer(&mut self, buffer_offset: BufferOffset) -> MultiBufferOffset {
7319        self.map_range_from_buffer(buffer_offset..buffer_offset)
7320            .start
7321    }
7322
7323    /// Map a range within the [`Buffer`] to a range within the [`MultiBuffer`]
7324    pub fn map_range_from_buffer(
7325        &mut self,
7326        buffer_range: Range<BufferOffset>,
7327    ) -> Range<MultiBufferOffset> {
7328        if buffer_range.start < self.buffer_offset {
7329            log::warn!(
7330                "Attempting to map a range from a buffer offset that starts before the current buffer offset"
7331            );
7332            return self.offset..self.offset;
7333        }
7334        let overshoot = buffer_range.start - self.buffer_offset;
7335        let excerpt_offset = self.excerpt_offset + overshoot;
7336        let excerpt_seek_dim = excerpt_offset;
7337        self.diff_transforms.seek(&excerpt_seek_dim, Bias::Right);
7338        if self.diff_transforms.start().excerpt_dimension > excerpt_offset {
7339            log::warn!(
7340                "Attempting to map a range from a buffer offset that starts before the current buffer offset"
7341            );
7342            return self.offset..self.offset;
7343        }
7344        let overshoot = excerpt_offset - self.diff_transforms.start().excerpt_dimension;
7345        let start = self.diff_transforms.start().output_dimension.0 + overshoot;
7346
7347        let end = if buffer_range.start < buffer_range.end {
7348            let overshoot = buffer_range.end - self.buffer_offset;
7349            let excerpt_offset = self.excerpt_offset + overshoot;
7350            let excerpt_seek_dim = excerpt_offset;
7351            self.diff_transforms
7352                .seek_forward(&excerpt_seek_dim, Bias::Right);
7353            let overshoot = excerpt_offset - self.diff_transforms.start().excerpt_dimension;
7354            // todo(lw): Clamp end to the excerpt boundaries
7355            self.diff_transforms.start().output_dimension.0 + overshoot
7356        } else {
7357            start
7358        };
7359
7360        start..end
7361    }
7362
7363    /// Returns true if the entirety of the given range is in the buffer's excerpt
7364    pub fn contains_buffer_range(&self, range: Range<BufferOffset>) -> bool {
7365        range.start >= self.excerpt.buffer_start_offset()
7366            && range.end <= self.excerpt.buffer_end_offset()
7367    }
7368
7369    pub fn max_buffer_row(&self) -> u32 {
7370        self.excerpt.max_buffer_row
7371    }
7372}
7373
7374impl ExcerptId {
7375    pub fn min() -> Self {
7376        Self(0)
7377    }
7378
7379    pub fn max() -> Self {
7380        Self(u32::MAX)
7381    }
7382
7383    pub fn to_proto(self) -> u64 {
7384        self.0 as _
7385    }
7386
7387    pub fn from_proto(proto: u64) -> Self {
7388        Self(proto as _)
7389    }
7390
7391    pub fn cmp(&self, other: &Self, snapshot: &MultiBufferSnapshot) -> cmp::Ordering {
7392        let a = snapshot.excerpt_locator_for_id(*self);
7393        let b = snapshot.excerpt_locator_for_id(*other);
7394        a.cmp(b).then_with(|| self.0.cmp(&other.0))
7395    }
7396}
7397
7398impl From<ExcerptId> for usize {
7399    fn from(val: ExcerptId) -> Self {
7400        val.0 as usize
7401    }
7402}
7403
7404impl fmt::Debug for Excerpt {
7405    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
7406        f.debug_struct("Excerpt")
7407            .field("id", &self.id)
7408            .field("locator", &self.locator)
7409            .field("buffer_id", &self.buffer_id)
7410            .field("range", &self.range)
7411            .field("text_summary", &self.text_summary)
7412            .field("has_trailing_newline", &self.has_trailing_newline)
7413            .finish()
7414    }
7415}
7416
7417impl sum_tree::Item for Excerpt {
7418    type Summary = ExcerptSummary;
7419
7420    fn summary(&self, _cx: ()) -> Self::Summary {
7421        let mut text = self.text_summary;
7422        if self.has_trailing_newline {
7423            text += TextSummary::from("\n");
7424        }
7425        ExcerptSummary {
7426            excerpt_id: self.id,
7427            excerpt_locator: self.locator.clone(),
7428            widest_line_number: self.max_buffer_row,
7429            text: text.into(),
7430        }
7431    }
7432}
7433
7434impl sum_tree::Item for ExcerptIdMapping {
7435    type Summary = ExcerptId;
7436
7437    fn summary(&self, _cx: ()) -> Self::Summary {
7438        self.id
7439    }
7440}
7441
7442impl sum_tree::KeyedItem for ExcerptIdMapping {
7443    type Key = ExcerptId;
7444
7445    fn key(&self) -> Self::Key {
7446        self.id
7447    }
7448}
7449
7450impl DiffTransform {
7451    fn hunk_info(&self) -> Option<DiffTransformHunkInfo> {
7452        match self {
7453            DiffTransform::DeletedHunk { hunk_info, .. } => Some(*hunk_info),
7454            DiffTransform::BufferContent {
7455                inserted_hunk_info, ..
7456            } => *inserted_hunk_info,
7457        }
7458    }
7459}
7460
7461impl sum_tree::Item for DiffTransform {
7462    type Summary = DiffTransformSummary;
7463
7464    fn summary(&self, _: <Self::Summary as sum_tree::Summary>::Context<'_>) -> Self::Summary {
7465        match self {
7466            DiffTransform::BufferContent { summary, .. } => DiffTransformSummary {
7467                input: *summary,
7468                output: *summary,
7469            },
7470            &DiffTransform::DeletedHunk { summary, .. } => DiffTransformSummary {
7471                input: MBTextSummary::default(),
7472                output: summary.into(),
7473            },
7474        }
7475    }
7476}
7477
7478impl DiffTransformSummary {
7479    fn excerpt_len(&self) -> ExcerptOffset {
7480        ExcerptDimension(self.input.len)
7481    }
7482}
7483
7484impl sum_tree::ContextLessSummary for DiffTransformSummary {
7485    fn zero() -> Self {
7486        DiffTransformSummary {
7487            input: MBTextSummary::default(),
7488            output: MBTextSummary::default(),
7489        }
7490    }
7491
7492    fn add_summary(&mut self, other: &Self) {
7493        self.input += other.input;
7494        self.output += other.output;
7495    }
7496}
7497
7498impl sum_tree::ContextLessSummary for ExcerptId {
7499    fn zero() -> Self {
7500        Self(0)
7501    }
7502
7503    fn add_summary(&mut self, summary: &Self) {
7504        *self = cmp::max(*self, *summary);
7505    }
7506}
7507
7508impl sum_tree::ContextLessSummary for ExcerptSummary {
7509    fn zero() -> Self {
7510        Self::default()
7511    }
7512
7513    fn add_summary(&mut self, summary: &Self) {
7514        debug_assert!(summary.excerpt_locator > self.excerpt_locator);
7515        self.excerpt_locator = summary.excerpt_locator.clone();
7516        self.text += summary.text;
7517        self.widest_line_number = cmp::max(self.widest_line_number, summary.widest_line_number);
7518    }
7519}
7520
7521impl<'a> sum_tree::SeekTarget<'a, ExcerptSummary, Option<&'a Locator>> for Locator {
7522    fn cmp(&self, cursor_location: &Option<&'a Locator>, _: ()) -> cmp::Ordering {
7523        Ord::cmp(&Some(self), cursor_location)
7524    }
7525}
7526
7527impl sum_tree::SeekTarget<'_, ExcerptSummary, ExcerptSummary> for Locator {
7528    fn cmp(&self, cursor_location: &ExcerptSummary, _: ()) -> cmp::Ordering {
7529        Ord::cmp(self, &cursor_location.excerpt_locator)
7530    }
7531}
7532
7533impl<'a, MBD> sum_tree::Dimension<'a, ExcerptSummary> for ExcerptDimension<MBD>
7534where
7535    MBD: MultiBufferDimension + Default,
7536{
7537    fn zero(_: ()) -> Self {
7538        ExcerptDimension(MBD::default())
7539    }
7540
7541    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: ()) {
7542        MultiBufferDimension::add_mb_text_summary(&mut self.0, &summary.text)
7543    }
7544}
7545
7546impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for Option<&'a Locator> {
7547    fn zero(_cx: ()) -> Self {
7548        Default::default()
7549    }
7550
7551    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: ()) {
7552        *self = Some(&summary.excerpt_locator);
7553    }
7554}
7555
7556impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for Option<ExcerptId> {
7557    fn zero(_cx: ()) -> Self {
7558        Default::default()
7559    }
7560
7561    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: ()) {
7562        *self = Some(summary.excerpt_id);
7563    }
7564}
7565
7566#[derive(Copy, Clone, PartialOrd, Ord, Eq, PartialEq, Debug)]
7567struct OutputDimension<T>(T);
7568
7569impl<T: PartialEq> PartialEq<T> for OutputDimension<T> {
7570    fn eq(&self, other: &T) -> bool {
7571        self.0 == *other
7572    }
7573}
7574
7575impl<T: PartialOrd> PartialOrd<T> for OutputDimension<T> {
7576    fn partial_cmp(&self, other: &T) -> Option<cmp::Ordering> {
7577        self.0.partial_cmp(other)
7578    }
7579}
7580
7581impl<R, T, U> ops::Sub<OutputDimension<U>> for OutputDimension<T>
7582where
7583    T: ops::Sub<U, Output = R>,
7584{
7585    type Output = R;
7586
7587    fn sub(self, other: OutputDimension<U>) -> Self::Output {
7588        self.0 - other.0
7589    }
7590}
7591
7592impl<R, T, U> ops::Add<U> for OutputDimension<T>
7593where
7594    T: ops::Add<U, Output = R>,
7595{
7596    type Output = OutputDimension<R>;
7597
7598    fn add(self, other: U) -> Self::Output {
7599        OutputDimension(self.0 + other)
7600    }
7601}
7602
7603impl<T, U> AddAssign<U> for OutputDimension<T>
7604where
7605    T: AddAssign<U>,
7606{
7607    fn add_assign(&mut self, other: U) {
7608        self.0 += other;
7609    }
7610}
7611
7612impl<T, U> SubAssign<U> for OutputDimension<T>
7613where
7614    T: SubAssign<U>,
7615{
7616    fn sub_assign(&mut self, other: U) {
7617        self.0 -= other;
7618    }
7619}
7620
7621#[derive(Copy, Clone, PartialOrd, Ord, Eq, PartialEq, Debug)]
7622struct ExcerptDimension<T>(T);
7623
7624impl<T: PartialEq> PartialEq<T> for ExcerptDimension<T> {
7625    fn eq(&self, other: &T) -> bool {
7626        self.0 == *other
7627    }
7628}
7629
7630impl<T: PartialOrd> PartialOrd<T> for ExcerptDimension<T> {
7631    fn partial_cmp(&self, other: &T) -> Option<cmp::Ordering> {
7632        self.0.partial_cmp(other)
7633    }
7634}
7635
7636impl ExcerptOffset {
7637    fn saturating_sub(self, other: ExcerptOffset) -> usize {
7638        self.0.saturating_sub(other.0)
7639    }
7640}
7641
7642impl<R, T, U> ops::Sub<ExcerptDimension<U>> for ExcerptDimension<T>
7643where
7644    T: ops::Sub<U, Output = R>,
7645{
7646    type Output = R;
7647
7648    fn sub(self, other: ExcerptDimension<U>) -> Self::Output {
7649        self.0 - other.0
7650    }
7651}
7652
7653impl<R, T, U> ops::Add<U> for ExcerptDimension<T>
7654where
7655    T: ops::Add<U, Output = R>,
7656{
7657    type Output = ExcerptDimension<R>;
7658
7659    fn add(self, other: U) -> Self::Output {
7660        ExcerptDimension(self.0 + other)
7661    }
7662}
7663
7664impl<T, U> AddAssign<U> for ExcerptDimension<T>
7665where
7666    T: AddAssign<U>,
7667{
7668    fn add_assign(&mut self, other: U) {
7669        self.0 += other;
7670    }
7671}
7672
7673impl<T, U> SubAssign<U> for ExcerptDimension<T>
7674where
7675    T: SubAssign<U>,
7676{
7677    fn sub_assign(&mut self, other: U) {
7678        self.0 -= other;
7679    }
7680}
7681
7682impl<'a> sum_tree::Dimension<'a, DiffTransformSummary> for MultiBufferOffset {
7683    fn zero(_: ()) -> Self {
7684        MultiBufferOffset::ZERO
7685    }
7686
7687    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7688        *self += summary.output.len;
7689    }
7690}
7691
7692impl<MBD> sum_tree::SeekTarget<'_, DiffTransformSummary, DiffTransformSummary>
7693    for ExcerptDimension<MBD>
7694where
7695    MBD: MultiBufferDimension + Ord,
7696{
7697    fn cmp(&self, cursor_location: &DiffTransformSummary, _: ()) -> cmp::Ordering {
7698        Ord::cmp(&self.0, &MBD::from_summary(&cursor_location.input))
7699    }
7700}
7701
7702impl<'a, MBD> sum_tree::SeekTarget<'a, DiffTransformSummary, DiffTransforms<MBD>>
7703    for ExcerptDimension<MBD>
7704where
7705    MBD: MultiBufferDimension + Ord,
7706{
7707    fn cmp(&self, cursor_location: &DiffTransforms<MBD>, _: ()) -> cmp::Ordering {
7708        Ord::cmp(&self.0, &cursor_location.excerpt_dimension.0)
7709    }
7710}
7711
7712impl<'a, MBD: MultiBufferDimension> sum_tree::Dimension<'a, DiffTransformSummary>
7713    for ExcerptDimension<MBD>
7714{
7715    fn zero(_: ()) -> Self {
7716        ExcerptDimension(MBD::default())
7717    }
7718
7719    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7720        self.0.add_mb_text_summary(&summary.input)
7721    }
7722}
7723
7724impl<'a, MBD> sum_tree::SeekTarget<'a, DiffTransformSummary, DiffTransforms<MBD>>
7725    for OutputDimension<MBD>
7726where
7727    MBD: MultiBufferDimension + Ord,
7728{
7729    fn cmp(&self, cursor_location: &DiffTransforms<MBD>, _: ()) -> cmp::Ordering {
7730        Ord::cmp(&self.0, &cursor_location.output_dimension.0)
7731    }
7732}
7733
7734impl<'a, MBD: MultiBufferDimension> sum_tree::Dimension<'a, DiffTransformSummary>
7735    for OutputDimension<MBD>
7736{
7737    fn zero(_: ()) -> Self {
7738        OutputDimension(MBD::default())
7739    }
7740
7741    fn add_summary(&mut self, summary: &'a DiffTransformSummary, _: ()) {
7742        self.0.add_mb_text_summary(&summary.output)
7743    }
7744}
7745
7746impl MultiBufferRows<'_> {
7747    pub fn seek(&mut self, MultiBufferRow(row): MultiBufferRow) {
7748        self.point = Point::new(row, 0);
7749        self.cursor.seek(&self.point);
7750    }
7751}
7752
7753impl Iterator for MultiBufferRows<'_> {
7754    type Item = RowInfo;
7755
7756    fn next(&mut self) -> Option<Self::Item> {
7757        if self.is_empty && self.point.row == 0 {
7758            self.point += Point::new(1, 0);
7759            return Some(RowInfo {
7760                buffer_id: None,
7761                buffer_row: Some(0),
7762                multibuffer_row: Some(MultiBufferRow(0)),
7763                diff_status: None,
7764                expand_info: None,
7765                wrapped_buffer_row: None,
7766            });
7767        }
7768
7769        let mut region = self.cursor.region()?;
7770        while self.point >= region.range.end {
7771            self.cursor.next();
7772            if let Some(next_region) = self.cursor.region() {
7773                region = next_region;
7774            } else if self.point == self.cursor.diff_transforms.end().output_dimension.0 {
7775                let multibuffer_row = MultiBufferRow(self.point.row);
7776                let last_excerpt = self
7777                    .cursor
7778                    .excerpts
7779                    .item()
7780                    .or(self.cursor.excerpts.prev_item())?;
7781                let last_row = last_excerpt
7782                    .range
7783                    .context
7784                    .end
7785                    .to_point(&last_excerpt.buffer)
7786                    .row;
7787
7788                let first_row = last_excerpt
7789                    .range
7790                    .context
7791                    .start
7792                    .to_point(&last_excerpt.buffer)
7793                    .row;
7794
7795                let expand_info = if self.is_singleton {
7796                    None
7797                } else {
7798                    let needs_expand_up = first_row == last_row
7799                        && last_row > 0
7800                        && !region.diff_hunk_status.is_some_and(|d| d.is_deleted());
7801                    let needs_expand_down = last_row < last_excerpt.buffer.max_point().row;
7802
7803                    if needs_expand_up && needs_expand_down {
7804                        Some(ExpandExcerptDirection::UpAndDown)
7805                    } else if needs_expand_up {
7806                        Some(ExpandExcerptDirection::Up)
7807                    } else if needs_expand_down {
7808                        Some(ExpandExcerptDirection::Down)
7809                    } else {
7810                        None
7811                    }
7812                    .map(|direction| ExpandInfo {
7813                        direction,
7814                        excerpt_id: last_excerpt.id,
7815                    })
7816                };
7817                self.point += Point::new(1, 0);
7818                return Some(RowInfo {
7819                    buffer_id: Some(last_excerpt.buffer_id),
7820                    buffer_row: Some(last_row),
7821                    multibuffer_row: Some(multibuffer_row),
7822                    diff_status: None,
7823                    wrapped_buffer_row: None,
7824                    expand_info,
7825                });
7826            } else {
7827                return None;
7828            };
7829        }
7830
7831        let overshoot = self.point - region.range.start;
7832        let buffer_point = region.buffer_range.start + overshoot;
7833        let expand_info = if self.is_singleton {
7834            None
7835        } else {
7836            let needs_expand_up = self.point.row == region.range.start.row
7837                && self.cursor.is_at_start_of_excerpt()
7838                && buffer_point.row > 0;
7839            let needs_expand_down = (region.excerpt.has_trailing_newline
7840                && self.point.row + 1 == region.range.end.row
7841                || !region.excerpt.has_trailing_newline && self.point.row == region.range.end.row)
7842                && self.cursor.is_at_end_of_excerpt()
7843                && buffer_point.row < region.buffer.max_point().row;
7844
7845            if needs_expand_up && needs_expand_down {
7846                Some(ExpandExcerptDirection::UpAndDown)
7847            } else if needs_expand_up {
7848                Some(ExpandExcerptDirection::Up)
7849            } else if needs_expand_down {
7850                Some(ExpandExcerptDirection::Down)
7851            } else {
7852                None
7853            }
7854            .map(|direction| ExpandInfo {
7855                direction,
7856                excerpt_id: region.excerpt.id,
7857            })
7858        };
7859
7860        let result = Some(RowInfo {
7861            buffer_id: Some(region.buffer.remote_id()),
7862            buffer_row: Some(buffer_point.row),
7863            multibuffer_row: Some(MultiBufferRow(self.point.row)),
7864            diff_status: region
7865                .diff_hunk_status
7866                .filter(|_| self.point < region.range.end),
7867            expand_info,
7868            wrapped_buffer_row: None,
7869        });
7870        self.point += Point::new(1, 0);
7871        result
7872    }
7873}
7874
7875impl<'a> MultiBufferChunks<'a> {
7876    pub fn offset(&self) -> MultiBufferOffset {
7877        self.range.start
7878    }
7879
7880    pub fn seek(&mut self, range: Range<MultiBufferOffset>) {
7881        self.diff_transforms.seek(&range.end, Bias::Right);
7882        let mut excerpt_end = self.diff_transforms.start().1;
7883        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7884            let overshoot = range.end - self.diff_transforms.start().0;
7885            excerpt_end += overshoot;
7886        }
7887
7888        self.diff_transforms.seek(&range.start, Bias::Right);
7889        let mut excerpt_start = self.diff_transforms.start().1;
7890        if let Some(DiffTransform::BufferContent { .. }) = self.diff_transforms.item() {
7891            let overshoot = range.start - self.diff_transforms.start().0;
7892            excerpt_start += overshoot;
7893        }
7894
7895        self.seek_to_excerpt_offset_range(excerpt_start..excerpt_end);
7896        self.buffer_chunk.take();
7897        self.range = range;
7898    }
7899
7900    fn seek_to_excerpt_offset_range(&mut self, new_range: Range<ExcerptOffset>) {
7901        self.excerpt_offset_range = new_range.clone();
7902        self.excerpts.seek(&new_range.start, Bias::Right);
7903        if let Some(excerpt) = self.excerpts.item() {
7904            let excerpt_start = *self.excerpts.start();
7905            if let Some(excerpt_chunks) = self
7906                .excerpt_chunks
7907                .as_mut()
7908                .filter(|chunks| excerpt.id == chunks.excerpt_id)
7909            {
7910                excerpt.seek_chunks(
7911                    excerpt_chunks,
7912                    (self.excerpt_offset_range.start - excerpt_start)
7913                        ..(self.excerpt_offset_range.end - excerpt_start),
7914                );
7915            } else {
7916                self.excerpt_chunks = Some(excerpt.chunks_in_range(
7917                    (self.excerpt_offset_range.start - excerpt_start)
7918                        ..(self.excerpt_offset_range.end - excerpt_start),
7919                    self.language_aware,
7920                ));
7921            }
7922        } else {
7923            self.excerpt_chunks = None;
7924        }
7925    }
7926
7927    fn next_excerpt_chunk(&mut self) -> Option<Chunk<'a>> {
7928        loop {
7929            if self.excerpt_offset_range.is_empty() {
7930                return None;
7931            } else if let Some(chunk) = self.excerpt_chunks.as_mut()?.next() {
7932                self.excerpt_offset_range.start += chunk.text.len();
7933                return Some(chunk);
7934            } else {
7935                self.excerpts.next();
7936                let excerpt = self.excerpts.item()?;
7937                self.excerpt_chunks = Some(excerpt.chunks_in_range(
7938                    0..(self.excerpt_offset_range.end - *self.excerpts.start()),
7939                    self.language_aware,
7940                ));
7941            }
7942        }
7943    }
7944}
7945
7946impl<'a> Iterator for ReversedMultiBufferChunks<'a> {
7947    type Item = &'a str;
7948
7949    fn next(&mut self) -> Option<Self::Item> {
7950        let mut region = self.cursor.region()?;
7951        if self.offset == region.range.start {
7952            self.cursor.prev();
7953            region = self.cursor.region()?;
7954            let start_overshoot = self.start.saturating_sub(region.range.start);
7955            self.current_chunks = Some(region.buffer.reversed_chunks_in_range(
7956                region.buffer_range.start + start_overshoot..region.buffer_range.end,
7957            ));
7958        }
7959
7960        if self.offset == region.range.end && region.has_trailing_newline {
7961            self.offset -= 1;
7962            Some("\n")
7963        } else {
7964            let chunk = self.current_chunks.as_mut().unwrap().next()?;
7965            self.offset -= chunk.len();
7966            Some(chunk)
7967        }
7968    }
7969}
7970
7971impl<'a> Iterator for MultiBufferChunks<'a> {
7972    type Item = Chunk<'a>;
7973
7974    fn next(&mut self) -> Option<Chunk<'a>> {
7975        if self.range.start >= self.range.end {
7976            return None;
7977        }
7978        if self.range.start == self.diff_transforms.end().0 {
7979            self.diff_transforms.next();
7980        }
7981
7982        let diff_transform_start = self.diff_transforms.start().0;
7983        let diff_transform_end = self.diff_transforms.end().0;
7984        debug_assert!(
7985            self.range.start < diff_transform_end,
7986            "{:?} < {:?} of ({1:?}..{2:?})",
7987            self.range.start,
7988            diff_transform_end,
7989            diff_transform_start
7990        );
7991
7992        let diff_transform = self.diff_transforms.item()?;
7993        match diff_transform {
7994            DiffTransform::BufferContent { .. } => {
7995                let chunk = if let Some(chunk) = &mut self.buffer_chunk {
7996                    chunk
7997                } else {
7998                    let chunk = self.next_excerpt_chunk().unwrap();
7999                    self.buffer_chunk.insert(chunk)
8000                };
8001
8002                let chunk_end = self.range.start + chunk.text.len();
8003                let diff_transform_end = diff_transform_end.min(self.range.end);
8004
8005                if diff_transform_end < chunk_end {
8006                    let split_idx = diff_transform_end - self.range.start;
8007                    let (before, after) = chunk.text.split_at(split_idx);
8008                    self.range.start = diff_transform_end;
8009                    let mask = 1u128.unbounded_shl(split_idx as u32).wrapping_sub(1);
8010                    let chars = chunk.chars & mask;
8011                    let tabs = chunk.tabs & mask;
8012
8013                    chunk.text = after;
8014                    chunk.chars = chunk.chars >> split_idx;
8015                    chunk.tabs = chunk.tabs >> split_idx;
8016
8017                    Some(Chunk {
8018                        text: before,
8019                        chars,
8020                        tabs,
8021                        ..chunk.clone()
8022                    })
8023                } else {
8024                    self.range.start = chunk_end;
8025                    self.buffer_chunk.take()
8026                }
8027            }
8028            DiffTransform::DeletedHunk {
8029                buffer_id,
8030                base_text_byte_range,
8031                has_trailing_newline,
8032                ..
8033            } => {
8034                let base_text_start =
8035                    base_text_byte_range.start + (self.range.start - diff_transform_start);
8036                let base_text_end =
8037                    base_text_byte_range.start + (self.range.end - diff_transform_start);
8038                let base_text_end = base_text_end.min(base_text_byte_range.end);
8039
8040                let mut chunks = if let Some((_, mut chunks)) = self
8041                    .diff_base_chunks
8042                    .take()
8043                    .filter(|(id, _)| id == buffer_id)
8044                {
8045                    if chunks.range().start != base_text_start || chunks.range().end < base_text_end
8046                    {
8047                        chunks.seek(base_text_start..base_text_end);
8048                    }
8049                    chunks
8050                } else {
8051                    let base_buffer = &self.diffs.get(buffer_id)?.base_text();
8052                    base_buffer.chunks(base_text_start..base_text_end, self.language_aware)
8053                };
8054
8055                let chunk = if let Some(chunk) = chunks.next() {
8056                    self.range.start += chunk.text.len();
8057                    self.diff_base_chunks = Some((*buffer_id, chunks));
8058                    chunk
8059                } else {
8060                    debug_assert!(has_trailing_newline);
8061                    self.range.start += "\n".len();
8062                    Chunk {
8063                        text: "\n",
8064                        chars: 1u128,
8065                        ..Default::default()
8066                    }
8067                };
8068                Some(chunk)
8069            }
8070        }
8071    }
8072}
8073
8074impl MultiBufferBytes<'_> {
8075    fn consume(&mut self, len: usize) {
8076        self.range.start += len;
8077        self.chunk = &self.chunk[len..];
8078
8079        if !self.range.is_empty() && self.chunk.is_empty() {
8080            if let Some(chunk) = self.excerpt_bytes.as_mut().and_then(|bytes| bytes.next()) {
8081                self.chunk = chunk;
8082            } else if self.has_trailing_newline {
8083                self.has_trailing_newline = false;
8084                self.chunk = b"\n";
8085            } else {
8086                self.cursor.next();
8087                if let Some(region) = self.cursor.region() {
8088                    let mut excerpt_bytes = region.buffer.bytes_in_range(
8089                        region.buffer_range.start
8090                            ..(region.buffer_range.start + (self.range.end - region.range.start))
8091                                .min(region.buffer_range.end),
8092                    );
8093                    self.chunk = excerpt_bytes.next().unwrap_or(&[]);
8094                    self.excerpt_bytes = Some(excerpt_bytes);
8095                    self.has_trailing_newline =
8096                        region.has_trailing_newline && self.range.end >= region.range.end;
8097                    if self.chunk.is_empty() && self.has_trailing_newline {
8098                        self.has_trailing_newline = false;
8099                        self.chunk = b"\n";
8100                    }
8101                }
8102            }
8103        }
8104    }
8105}
8106
8107impl<'a> Iterator for MultiBufferBytes<'a> {
8108    type Item = &'a [u8];
8109
8110    fn next(&mut self) -> Option<Self::Item> {
8111        let chunk = self.chunk;
8112        if chunk.is_empty() {
8113            None
8114        } else {
8115            self.consume(chunk.len());
8116            Some(chunk)
8117        }
8118    }
8119}
8120
8121impl io::Read for MultiBufferBytes<'_> {
8122    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
8123        let len = cmp::min(buf.len(), self.chunk.len());
8124        buf[..len].copy_from_slice(&self.chunk[..len]);
8125        if len > 0 {
8126            self.consume(len);
8127        }
8128        Ok(len)
8129    }
8130}
8131
8132impl io::Read for ReversedMultiBufferBytes<'_> {
8133    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
8134        let len = cmp::min(buf.len(), self.chunk.len());
8135        buf[..len].copy_from_slice(&self.chunk[..len]);
8136        buf[..len].reverse();
8137        if len > 0 {
8138            self.range.end -= len;
8139            self.chunk = &self.chunk[..self.chunk.len() - len];
8140            if !self.range.is_empty()
8141                && self.chunk.is_empty()
8142                && let Some(chunk) = self.chunks.next()
8143            {
8144                self.chunk = chunk.as_bytes();
8145            }
8146        }
8147        Ok(len)
8148    }
8149}
8150
8151impl<'a> Iterator for ExcerptChunks<'a> {
8152    type Item = Chunk<'a>;
8153
8154    fn next(&mut self) -> Option<Self::Item> {
8155        if let Some(chunk) = self.content_chunks.next() {
8156            return Some(chunk);
8157        }
8158
8159        if self.has_footer {
8160            let text = "\n";
8161            let chars = 0b1;
8162            self.has_footer = false;
8163            return Some(Chunk {
8164                text,
8165                chars,
8166                ..Default::default()
8167            });
8168        }
8169
8170        None
8171    }
8172}
8173
8174impl ToOffset for Point {
8175    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8176        snapshot.point_to_offset(*self)
8177    }
8178    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8179        snapshot.point_to_offset_utf16(*self)
8180    }
8181}
8182
8183impl ToOffset for MultiBufferOffset {
8184    #[track_caller]
8185    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8186        assert!(
8187            *self <= snapshot.len(),
8188            "offset {} is greater than the snapshot.len() {}",
8189            self.0,
8190            snapshot.len().0,
8191        );
8192        *self
8193    }
8194    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8195        snapshot.offset_to_offset_utf16(*self)
8196    }
8197}
8198
8199impl ToOffset for MultiBufferOffsetUtf16 {
8200    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8201        snapshot.offset_utf16_to_offset(*self)
8202    }
8203
8204    fn to_offset_utf16(&self, _snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8205        *self
8206    }
8207}
8208
8209impl ToOffset for PointUtf16 {
8210    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffset {
8211        snapshot.point_utf16_to_offset(*self)
8212    }
8213    fn to_offset_utf16(&self, snapshot: &MultiBufferSnapshot) -> MultiBufferOffsetUtf16 {
8214        snapshot.point_utf16_to_offset_utf16(*self)
8215    }
8216}
8217
8218impl ToPoint for MultiBufferOffset {
8219    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
8220        snapshot.offset_to_point(*self)
8221    }
8222    fn to_point_utf16<'a>(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16 {
8223        snapshot.offset_to_point_utf16(*self)
8224    }
8225}
8226
8227impl ToPoint for Point {
8228    fn to_point<'a>(&self, _: &MultiBufferSnapshot) -> Point {
8229        *self
8230    }
8231    fn to_point_utf16<'a>(&self, snapshot: &MultiBufferSnapshot) -> PointUtf16 {
8232        snapshot.point_to_point_utf16(*self)
8233    }
8234}
8235
8236impl ToPoint for PointUtf16 {
8237    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
8238        snapshot.point_utf16_to_point(*self)
8239    }
8240    fn to_point_utf16<'a>(&self, _: &MultiBufferSnapshot) -> PointUtf16 {
8241        *self
8242    }
8243}
8244
8245impl From<ExcerptId> for EntityId {
8246    fn from(id: ExcerptId) -> Self {
8247        EntityId::from(id.0 as u64)
8248    }
8249}
8250
8251#[cfg(debug_assertions)]
8252pub mod debug {
8253    use super::*;
8254
8255    pub trait ToMultiBufferDebugRanges {
8256        fn to_multi_buffer_debug_ranges(
8257            &self,
8258            snapshot: &MultiBufferSnapshot,
8259        ) -> Vec<Range<MultiBufferOffset>>;
8260    }
8261
8262    impl<T: ToOffset> ToMultiBufferDebugRanges for T {
8263        fn to_multi_buffer_debug_ranges(
8264            &self,
8265            snapshot: &MultiBufferSnapshot,
8266        ) -> Vec<Range<MultiBufferOffset>> {
8267            [self.to_offset(snapshot)].to_multi_buffer_debug_ranges(snapshot)
8268        }
8269    }
8270
8271    impl<T: ToOffset> ToMultiBufferDebugRanges for Range<T> {
8272        fn to_multi_buffer_debug_ranges(
8273            &self,
8274            snapshot: &MultiBufferSnapshot,
8275        ) -> Vec<Range<MultiBufferOffset>> {
8276            [self.start.to_offset(snapshot)..self.end.to_offset(snapshot)]
8277                .to_multi_buffer_debug_ranges(snapshot)
8278        }
8279    }
8280
8281    impl<T: ToOffset> ToMultiBufferDebugRanges for Vec<T> {
8282        fn to_multi_buffer_debug_ranges(
8283            &self,
8284            snapshot: &MultiBufferSnapshot,
8285        ) -> Vec<Range<MultiBufferOffset>> {
8286            self.as_slice().to_multi_buffer_debug_ranges(snapshot)
8287        }
8288    }
8289
8290    impl<T: ToOffset> ToMultiBufferDebugRanges for Vec<Range<T>> {
8291        fn to_multi_buffer_debug_ranges(
8292            &self,
8293            snapshot: &MultiBufferSnapshot,
8294        ) -> Vec<Range<MultiBufferOffset>> {
8295            self.as_slice().to_multi_buffer_debug_ranges(snapshot)
8296        }
8297    }
8298
8299    impl<T: ToOffset> ToMultiBufferDebugRanges for [T] {
8300        fn to_multi_buffer_debug_ranges(
8301            &self,
8302            snapshot: &MultiBufferSnapshot,
8303        ) -> Vec<Range<MultiBufferOffset>> {
8304            self.iter()
8305                .map(|item| {
8306                    let offset = item.to_offset(snapshot);
8307                    offset..offset
8308                })
8309                .collect()
8310        }
8311    }
8312
8313    impl<T: ToOffset> ToMultiBufferDebugRanges for [Range<T>] {
8314        fn to_multi_buffer_debug_ranges(
8315            &self,
8316            snapshot: &MultiBufferSnapshot,
8317        ) -> Vec<Range<MultiBufferOffset>> {
8318            self.iter()
8319                .map(|range| range.start.to_offset(snapshot)..range.end.to_offset(snapshot))
8320                .collect()
8321        }
8322    }
8323}