multi_buffer.rs

   1mod anchor;
   2
   3pub use anchor::{Anchor, AnchorRangeExt};
   4use anyhow::Result;
   5use clock::ReplicaId;
   6use collections::{HashMap, HashSet};
   7use gpui::{AppContext, Entity, ModelContext, ModelHandle, Task};
   8pub use language::Completion;
   9use language::{
  10    Buffer, BufferChunks, BufferSnapshot, Chunk, DiagnosticEntry, Event, File, Language, Outline,
  11    OutlineItem, Selection, ToOffset as _, ToPoint as _, TransactionId,
  12};
  13use std::{
  14    cell::{Ref, RefCell},
  15    cmp, fmt, io,
  16    iter::{self, FromIterator},
  17    ops::{Range, Sub},
  18    str,
  19    sync::Arc,
  20    time::{Duration, Instant},
  21};
  22use sum_tree::{Bias, Cursor, SumTree};
  23use text::{
  24    locator::Locator,
  25    rope::TextDimension,
  26    subscription::{Subscription, Topic},
  27    AnchorRangeExt as _, Edit, Point, PointUtf16, TextSummary,
  28};
  29use theme::SyntaxTheme;
  30use util::post_inc;
  31
  32const NEWLINES: &'static [u8] = &[b'\n'; u8::MAX as usize];
  33
  34pub type ExcerptId = Locator;
  35
  36pub struct MultiBuffer {
  37    snapshot: RefCell<MultiBufferSnapshot>,
  38    buffers: RefCell<HashMap<usize, BufferState>>,
  39    subscriptions: Topic,
  40    singleton: bool,
  41    replica_id: ReplicaId,
  42    history: History,
  43}
  44
  45struct History {
  46    next_transaction_id: usize,
  47    undo_stack: Vec<Transaction>,
  48    redo_stack: Vec<Transaction>,
  49    transaction_depth: usize,
  50    group_interval: Duration,
  51}
  52
  53#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord, Debug)]
  54pub enum CharKind {
  55    Newline,
  56    Punctuation,
  57    Whitespace,
  58    Word,
  59}
  60
  61struct Transaction {
  62    id: usize,
  63    buffer_transactions: HashSet<(usize, text::TransactionId)>,
  64    first_edit_at: Instant,
  65    last_edit_at: Instant,
  66}
  67
  68pub trait ToOffset: 'static + fmt::Debug {
  69    fn to_offset(&self, snapshot: &MultiBufferSnapshot) -> usize;
  70}
  71
  72pub trait ToPoint: 'static + fmt::Debug {
  73    fn to_point(&self, snapshot: &MultiBufferSnapshot) -> Point;
  74}
  75
  76struct BufferState {
  77    buffer: ModelHandle<Buffer>,
  78    last_version: clock::Global,
  79    last_parse_count: usize,
  80    last_selections_update_count: usize,
  81    last_diagnostics_update_count: usize,
  82    excerpts: Vec<ExcerptId>,
  83    _subscriptions: [gpui::Subscription; 2],
  84}
  85
  86#[derive(Clone, Default)]
  87pub struct MultiBufferSnapshot {
  88    singleton: bool,
  89    excerpts: SumTree<Excerpt>,
  90    parse_count: usize,
  91    diagnostics_update_count: usize,
  92    is_dirty: bool,
  93    has_conflict: bool,
  94}
  95
  96pub struct ExcerptProperties<'a, T> {
  97    pub buffer: &'a ModelHandle<Buffer>,
  98    pub range: Range<T>,
  99}
 100
 101#[derive(Clone)]
 102struct Excerpt {
 103    id: ExcerptId,
 104    buffer_id: usize,
 105    buffer: BufferSnapshot,
 106    range: Range<text::Anchor>,
 107    max_buffer_row: u32,
 108    text_summary: TextSummary,
 109    has_trailing_newline: bool,
 110}
 111
 112#[derive(Clone, Debug, Default)]
 113struct ExcerptSummary {
 114    excerpt_id: ExcerptId,
 115    max_buffer_row: u32,
 116    text: TextSummary,
 117}
 118
 119pub struct MultiBufferRows<'a> {
 120    buffer_row_range: Range<u32>,
 121    excerpts: Cursor<'a, Excerpt, Point>,
 122}
 123
 124pub struct MultiBufferChunks<'a> {
 125    range: Range<usize>,
 126    excerpts: Cursor<'a, Excerpt, usize>,
 127    excerpt_chunks: Option<ExcerptChunks<'a>>,
 128    theme: Option<&'a SyntaxTheme>,
 129}
 130
 131pub struct MultiBufferBytes<'a> {
 132    range: Range<usize>,
 133    excerpts: Cursor<'a, Excerpt, usize>,
 134    excerpt_bytes: Option<ExcerptBytes<'a>>,
 135    chunk: &'a [u8],
 136}
 137
 138struct ExcerptChunks<'a> {
 139    content_chunks: BufferChunks<'a>,
 140    footer_height: usize,
 141}
 142
 143struct ExcerptBytes<'a> {
 144    content_bytes: language::rope::Bytes<'a>,
 145    footer_height: usize,
 146}
 147
 148impl MultiBuffer {
 149    pub fn new(replica_id: ReplicaId) -> Self {
 150        Self {
 151            snapshot: Default::default(),
 152            buffers: Default::default(),
 153            subscriptions: Default::default(),
 154            singleton: false,
 155            replica_id,
 156            history: History {
 157                next_transaction_id: Default::default(),
 158                undo_stack: Default::default(),
 159                redo_stack: Default::default(),
 160                transaction_depth: 0,
 161                group_interval: Duration::from_millis(300),
 162            },
 163        }
 164    }
 165
 166    pub fn singleton(buffer: ModelHandle<Buffer>, cx: &mut ModelContext<Self>) -> Self {
 167        let mut this = Self::new(buffer.read(cx).replica_id());
 168        this.singleton = true;
 169        this.push_excerpt(
 170            ExcerptProperties {
 171                buffer: &buffer,
 172                range: text::Anchor::min()..text::Anchor::max(),
 173            },
 174            cx,
 175        );
 176        this.snapshot.borrow_mut().singleton = true;
 177        this
 178    }
 179
 180    #[cfg(any(test, feature = "test-support"))]
 181    pub fn build_simple(text: &str, cx: &mut gpui::MutableAppContext) -> ModelHandle<Self> {
 182        let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
 183        cx.add_model(|cx| Self::singleton(buffer, cx))
 184    }
 185
 186    #[cfg(any(test, feature = "test-support"))]
 187    pub fn build_random(
 188        mut rng: &mut impl rand::Rng,
 189        cx: &mut gpui::MutableAppContext,
 190    ) -> ModelHandle<Self> {
 191        use rand::prelude::*;
 192        use std::env;
 193        use text::RandomCharIter;
 194
 195        let max_excerpts = env::var("MAX_EXCERPTS")
 196            .map(|i| i.parse().expect("invalid `MAX_EXCERPTS` variable"))
 197            .unwrap_or(5);
 198        let excerpts = rng.gen_range(1..=max_excerpts);
 199
 200        cx.add_model(|cx| {
 201            let mut multibuffer = MultiBuffer::new(0);
 202            let mut buffers = Vec::new();
 203            for _ in 0..excerpts {
 204                let buffer_handle = if rng.gen() || buffers.is_empty() {
 205                    let text = RandomCharIter::new(&mut rng).take(10).collect::<String>();
 206                    buffers.push(cx.add_model(|cx| Buffer::new(0, text, cx)));
 207                    let buffer = buffers.last().unwrap();
 208                    log::info!(
 209                        "Creating new buffer {} with text: {:?}",
 210                        buffer.id(),
 211                        buffer.read(cx).text()
 212                    );
 213                    buffers.last().unwrap()
 214                } else {
 215                    buffers.choose(rng).unwrap()
 216                };
 217
 218                let buffer = buffer_handle.read(cx);
 219                let end_ix = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Right);
 220                let start_ix = buffer.clip_offset(rng.gen_range(0..=end_ix), Bias::Left);
 221                let header_height = rng.gen_range(0..=5);
 222                log::info!(
 223                    "Inserting excerpt from buffer {} with header height {} and range {:?}: {:?}",
 224                    buffer_handle.id(),
 225                    header_height,
 226                    start_ix..end_ix,
 227                    &buffer.text()[start_ix..end_ix]
 228                );
 229
 230                multibuffer.push_excerpt(
 231                    ExcerptProperties {
 232                        buffer: buffer_handle,
 233                        range: start_ix..end_ix,
 234                    },
 235                    cx,
 236                );
 237            }
 238            multibuffer
 239        })
 240    }
 241
 242    pub fn replica_id(&self) -> ReplicaId {
 243        self.replica_id
 244    }
 245
 246    pub fn snapshot(&self, cx: &AppContext) -> MultiBufferSnapshot {
 247        self.sync(cx);
 248        self.snapshot.borrow().clone()
 249    }
 250
 251    pub fn read(&self, cx: &AppContext) -> Ref<MultiBufferSnapshot> {
 252        self.sync(cx);
 253        self.snapshot.borrow()
 254    }
 255
 256    pub fn as_singleton(&self) -> Option<ModelHandle<Buffer>> {
 257        if self.singleton {
 258            return Some(
 259                self.buffers
 260                    .borrow()
 261                    .values()
 262                    .next()
 263                    .unwrap()
 264                    .buffer
 265                    .clone(),
 266            );
 267        } else {
 268            None
 269        }
 270    }
 271
 272    pub fn subscribe(&mut self) -> Subscription {
 273        self.subscriptions.subscribe()
 274    }
 275
 276    pub fn edit<I, S, T>(&mut self, ranges: I, new_text: T, cx: &mut ModelContext<Self>)
 277    where
 278        I: IntoIterator<Item = Range<S>>,
 279        S: ToOffset,
 280        T: Into<String>,
 281    {
 282        self.edit_internal(ranges, new_text, false, cx)
 283    }
 284
 285    pub fn edit_with_autoindent<I, S, T>(
 286        &mut self,
 287        ranges: I,
 288        new_text: T,
 289        cx: &mut ModelContext<Self>,
 290    ) where
 291        I: IntoIterator<Item = Range<S>>,
 292        S: ToOffset,
 293        T: Into<String>,
 294    {
 295        self.edit_internal(ranges, new_text, true, cx)
 296    }
 297
 298    pub fn edit_internal<I, S, T>(
 299        &mut self,
 300        ranges_iter: I,
 301        new_text: T,
 302        autoindent: bool,
 303        cx: &mut ModelContext<Self>,
 304    ) where
 305        I: IntoIterator<Item = Range<S>>,
 306        S: ToOffset,
 307        T: Into<String>,
 308    {
 309        if let Some(buffer) = self.as_singleton() {
 310            let snapshot = self.read(cx);
 311            let ranges = ranges_iter
 312                .into_iter()
 313                .map(|range| range.start.to_offset(&snapshot)..range.end.to_offset(&snapshot));
 314            return buffer.update(cx, |buffer, cx| {
 315                if autoindent {
 316                    buffer.edit_with_autoindent(ranges, new_text, cx)
 317                } else {
 318                    buffer.edit(ranges, new_text, cx)
 319                }
 320            });
 321        }
 322
 323        let snapshot = self.read(cx);
 324        let mut buffer_edits: HashMap<usize, Vec<(Range<usize>, bool)>> = Default::default();
 325        let mut cursor = snapshot.excerpts.cursor::<usize>();
 326        for range in ranges_iter {
 327            let start = range.start.to_offset(&snapshot);
 328            let end = range.end.to_offset(&snapshot);
 329            cursor.seek(&start, Bias::Right, &());
 330            if cursor.item().is_none() && start == *cursor.start() {
 331                cursor.prev(&());
 332            }
 333            let start_excerpt = cursor.item().expect("start offset out of bounds");
 334            let start_overshoot = start - cursor.start();
 335            let buffer_start =
 336                start_excerpt.range.start.to_offset(&start_excerpt.buffer) + start_overshoot;
 337
 338            cursor.seek(&end, Bias::Right, &());
 339            if cursor.item().is_none() && end == *cursor.start() {
 340                cursor.prev(&());
 341            }
 342            let end_excerpt = cursor.item().expect("end offset out of bounds");
 343            let end_overshoot = end - cursor.start();
 344            let buffer_end = end_excerpt.range.start.to_offset(&end_excerpt.buffer) + end_overshoot;
 345
 346            if start_excerpt.id == end_excerpt.id {
 347                buffer_edits
 348                    .entry(start_excerpt.buffer_id)
 349                    .or_insert(Vec::new())
 350                    .push((buffer_start..buffer_end, true));
 351            } else {
 352                let start_excerpt_range =
 353                    buffer_start..start_excerpt.range.end.to_offset(&start_excerpt.buffer);
 354                let end_excerpt_range =
 355                    end_excerpt.range.start.to_offset(&end_excerpt.buffer)..buffer_end;
 356                buffer_edits
 357                    .entry(start_excerpt.buffer_id)
 358                    .or_insert(Vec::new())
 359                    .push((start_excerpt_range, true));
 360                buffer_edits
 361                    .entry(end_excerpt.buffer_id)
 362                    .or_insert(Vec::new())
 363                    .push((end_excerpt_range, false));
 364
 365                cursor.seek(&start, Bias::Right, &());
 366                cursor.next(&());
 367                while let Some(excerpt) = cursor.item() {
 368                    if excerpt.id == end_excerpt.id {
 369                        break;
 370                    }
 371                    buffer_edits
 372                        .entry(excerpt.buffer_id)
 373                        .or_insert(Vec::new())
 374                        .push((excerpt.range.to_offset(&excerpt.buffer), false));
 375                    cursor.next(&());
 376                }
 377            }
 378        }
 379
 380        let new_text = new_text.into();
 381        for (buffer_id, mut edits) in buffer_edits {
 382            edits.sort_unstable_by_key(|(range, _)| range.start);
 383            self.buffers.borrow()[&buffer_id]
 384                .buffer
 385                .update(cx, |buffer, cx| {
 386                    let mut edits = edits.into_iter().peekable();
 387                    let mut insertions = Vec::new();
 388                    let mut deletions = Vec::new();
 389                    while let Some((mut range, mut is_insertion)) = edits.next() {
 390                        while let Some((next_range, next_is_insertion)) = edits.peek() {
 391                            if range.end >= next_range.start {
 392                                range.end = cmp::max(next_range.end, range.end);
 393                                is_insertion |= *next_is_insertion;
 394                                edits.next();
 395                            } else {
 396                                break;
 397                            }
 398                        }
 399
 400                        if is_insertion {
 401                            insertions.push(
 402                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
 403                            );
 404                        } else if !range.is_empty() {
 405                            deletions.push(
 406                                buffer.anchor_before(range.start)..buffer.anchor_before(range.end),
 407                            );
 408                        }
 409                    }
 410
 411                    if autoindent {
 412                        buffer.edit_with_autoindent(deletions, "", cx);
 413                        buffer.edit_with_autoindent(insertions, new_text.clone(), cx);
 414                    } else {
 415                        buffer.edit(deletions, "", cx);
 416                        buffer.edit(insertions, new_text.clone(), cx);
 417                    }
 418                })
 419        }
 420    }
 421
 422    pub fn start_transaction(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
 423        self.start_transaction_at(Instant::now(), cx)
 424    }
 425
 426    pub(crate) fn start_transaction_at(
 427        &mut self,
 428        now: Instant,
 429        cx: &mut ModelContext<Self>,
 430    ) -> Option<TransactionId> {
 431        if let Some(buffer) = self.as_singleton() {
 432            return buffer.update(cx, |buffer, _| buffer.start_transaction_at(now));
 433        }
 434
 435        for BufferState { buffer, .. } in self.buffers.borrow().values() {
 436            buffer.update(cx, |buffer, _| buffer.start_transaction_at(now));
 437        }
 438        self.history.start_transaction(now)
 439    }
 440
 441    pub fn end_transaction(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
 442        self.end_transaction_at(Instant::now(), cx)
 443    }
 444
 445    pub(crate) fn end_transaction_at(
 446        &mut self,
 447        now: Instant,
 448        cx: &mut ModelContext<Self>,
 449    ) -> Option<TransactionId> {
 450        if let Some(buffer) = self.as_singleton() {
 451            return buffer.update(cx, |buffer, cx| buffer.end_transaction_at(now, cx));
 452        }
 453
 454        let mut buffer_transactions = HashSet::default();
 455        for BufferState { buffer, .. } in self.buffers.borrow().values() {
 456            if let Some(transaction_id) =
 457                buffer.update(cx, |buffer, cx| buffer.end_transaction_at(now, cx))
 458            {
 459                buffer_transactions.insert((buffer.id(), transaction_id));
 460            }
 461        }
 462
 463        if self.history.end_transaction(now, buffer_transactions) {
 464            let transaction_id = self.history.group().unwrap();
 465            Some(transaction_id)
 466        } else {
 467            None
 468        }
 469    }
 470
 471    pub fn avoid_grouping_next_transaction(&mut self, cx: &mut ModelContext<Self>) {
 472        for BufferState { buffer, .. } in self.buffers.borrow().values() {
 473            buffer.update(cx, |buffer, _| buffer.avoid_grouping_next_transaction());
 474        }
 475    }
 476
 477    pub fn set_active_selections(
 478        &mut self,
 479        selections: &[Selection<Anchor>],
 480        cx: &mut ModelContext<Self>,
 481    ) {
 482        let mut selections_by_buffer: HashMap<usize, Vec<Selection<text::Anchor>>> =
 483            Default::default();
 484        let snapshot = self.read(cx);
 485        let mut cursor = snapshot.excerpts.cursor::<Option<&ExcerptId>>();
 486        for selection in selections {
 487            cursor.seek(&Some(&selection.start.excerpt_id), Bias::Left, &());
 488            while let Some(excerpt) = cursor.item() {
 489                if excerpt.id > selection.end.excerpt_id {
 490                    break;
 491                }
 492
 493                let mut start = excerpt.range.start.clone();
 494                let mut end = excerpt.range.end.clone();
 495                if excerpt.id == selection.start.excerpt_id {
 496                    start = selection.start.text_anchor.clone();
 497                }
 498                if excerpt.id == selection.end.excerpt_id {
 499                    end = selection.end.text_anchor.clone();
 500                }
 501                selections_by_buffer
 502                    .entry(excerpt.buffer_id)
 503                    .or_default()
 504                    .push(Selection {
 505                        id: selection.id,
 506                        start,
 507                        end,
 508                        reversed: selection.reversed,
 509                        goal: selection.goal,
 510                    });
 511
 512                cursor.next(&());
 513            }
 514        }
 515
 516        for (buffer_id, buffer_state) in self.buffers.borrow().iter() {
 517            if !selections_by_buffer.contains_key(buffer_id) {
 518                buffer_state
 519                    .buffer
 520                    .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
 521            }
 522        }
 523
 524        for (buffer_id, mut selections) in selections_by_buffer {
 525            self.buffers.borrow()[&buffer_id]
 526                .buffer
 527                .update(cx, |buffer, cx| {
 528                    selections.sort_unstable_by(|a, b| a.start.cmp(&b.start, buffer).unwrap());
 529                    let mut selections = selections.into_iter().peekable();
 530                    let merged_selections = Arc::from_iter(iter::from_fn(|| {
 531                        let mut selection = selections.next()?;
 532                        while let Some(next_selection) = selections.peek() {
 533                            if selection
 534                                .end
 535                                .cmp(&next_selection.start, buffer)
 536                                .unwrap()
 537                                .is_ge()
 538                            {
 539                                let next_selection = selections.next().unwrap();
 540                                if next_selection
 541                                    .end
 542                                    .cmp(&selection.end, buffer)
 543                                    .unwrap()
 544                                    .is_ge()
 545                                {
 546                                    selection.end = next_selection.end;
 547                                }
 548                            } else {
 549                                break;
 550                            }
 551                        }
 552                        Some(selection)
 553                    }));
 554                    buffer.set_active_selections(merged_selections, cx);
 555                });
 556        }
 557    }
 558
 559    pub fn remove_active_selections(&mut self, cx: &mut ModelContext<Self>) {
 560        for buffer in self.buffers.borrow().values() {
 561            buffer
 562                .buffer
 563                .update(cx, |buffer, cx| buffer.remove_active_selections(cx));
 564        }
 565    }
 566
 567    pub fn undo(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
 568        if let Some(buffer) = self.as_singleton() {
 569            return buffer.update(cx, |buffer, cx| buffer.undo(cx));
 570        }
 571
 572        while let Some(transaction) = self.history.pop_undo() {
 573            let mut undone = false;
 574            for (buffer_id, buffer_transaction_id) in &transaction.buffer_transactions {
 575                if let Some(BufferState { buffer, .. }) = self.buffers.borrow().get(&buffer_id) {
 576                    undone |= buffer.update(cx, |buf, cx| {
 577                        buf.undo_transaction(*buffer_transaction_id, cx)
 578                    });
 579                }
 580            }
 581
 582            if undone {
 583                return Some(transaction.id);
 584            }
 585        }
 586
 587        None
 588    }
 589
 590    pub fn redo(&mut self, cx: &mut ModelContext<Self>) -> Option<TransactionId> {
 591        if let Some(buffer) = self.as_singleton() {
 592            return buffer.update(cx, |buffer, cx| buffer.redo(cx));
 593        }
 594
 595        while let Some(transaction) = self.history.pop_redo() {
 596            let mut redone = false;
 597            for (buffer_id, buffer_transaction_id) in &transaction.buffer_transactions {
 598                if let Some(BufferState { buffer, .. }) = self.buffers.borrow().get(&buffer_id) {
 599                    redone |= buffer.update(cx, |buf, cx| {
 600                        buf.redo_transaction(*buffer_transaction_id, cx)
 601                    });
 602                }
 603            }
 604
 605            if redone {
 606                return Some(transaction.id);
 607            }
 608        }
 609
 610        None
 611    }
 612
 613    pub fn push_excerpt<O>(
 614        &mut self,
 615        props: ExcerptProperties<O>,
 616        cx: &mut ModelContext<Self>,
 617    ) -> ExcerptId
 618    where
 619        O: text::ToOffset,
 620    {
 621        self.insert_excerpt_after(&ExcerptId::max(), props, cx)
 622    }
 623
 624    pub fn insert_excerpt_after<O>(
 625        &mut self,
 626        prev_excerpt_id: &ExcerptId,
 627        props: ExcerptProperties<O>,
 628        cx: &mut ModelContext<Self>,
 629    ) -> ExcerptId
 630    where
 631        O: text::ToOffset,
 632    {
 633        assert_eq!(self.history.transaction_depth, 0);
 634        self.sync(cx);
 635
 636        let buffer_snapshot = props.buffer.read(cx).snapshot();
 637        let range = buffer_snapshot.anchor_before(&props.range.start)
 638            ..buffer_snapshot.anchor_after(&props.range.end);
 639        let mut snapshot = self.snapshot.borrow_mut();
 640        let mut cursor = snapshot.excerpts.cursor::<Option<&ExcerptId>>();
 641        let mut new_excerpts = cursor.slice(&Some(prev_excerpt_id), Bias::Right, &());
 642
 643        let mut prev_id = ExcerptId::min();
 644        let edit_start = new_excerpts.summary().text.bytes;
 645        new_excerpts.update_last(
 646            |excerpt| {
 647                excerpt.has_trailing_newline = true;
 648                prev_id = excerpt.id.clone();
 649            },
 650            &(),
 651        );
 652
 653        let mut next_id = ExcerptId::max();
 654        if let Some(next_excerpt) = cursor.item() {
 655            next_id = next_excerpt.id.clone();
 656        }
 657
 658        let id = ExcerptId::between(&prev_id, &next_id);
 659
 660        let mut buffers = self.buffers.borrow_mut();
 661        let buffer_state = buffers
 662            .entry(props.buffer.id())
 663            .or_insert_with(|| BufferState {
 664                last_version: buffer_snapshot.version().clone(),
 665                last_parse_count: buffer_snapshot.parse_count(),
 666                last_selections_update_count: buffer_snapshot.selections_update_count(),
 667                last_diagnostics_update_count: buffer_snapshot.diagnostics_update_count(),
 668                excerpts: Default::default(),
 669                _subscriptions: [
 670                    cx.observe(&props.buffer, |_, _, cx| cx.notify()),
 671                    cx.subscribe(&props.buffer, Self::on_buffer_event),
 672                ],
 673                buffer: props.buffer.clone(),
 674            });
 675        if let Err(ix) = buffer_state.excerpts.binary_search(&id) {
 676            buffer_state.excerpts.insert(ix, id.clone());
 677        }
 678
 679        let excerpt = Excerpt::new(
 680            id.clone(),
 681            props.buffer.id(),
 682            buffer_snapshot,
 683            range,
 684            cursor.item().is_some(),
 685        );
 686        new_excerpts.push(excerpt, &());
 687        let edit_end = new_excerpts.summary().text.bytes;
 688
 689        new_excerpts.push_tree(cursor.suffix(&()), &());
 690        drop(cursor);
 691        snapshot.excerpts = new_excerpts;
 692
 693        self.subscriptions.publish_mut([Edit {
 694            old: edit_start..edit_start,
 695            new: edit_start..edit_end,
 696        }]);
 697
 698        cx.notify();
 699        id
 700    }
 701
 702    pub fn excerpt_ids_for_buffer(&self, buffer: &ModelHandle<Buffer>) -> Vec<ExcerptId> {
 703        self.buffers
 704            .borrow()
 705            .get(&buffer.id())
 706            .map_or(Vec::new(), |state| state.excerpts.clone())
 707    }
 708
 709    pub fn excerpted_buffers<'a, T: ToOffset>(
 710        &'a self,
 711        range: Range<T>,
 712        cx: &AppContext,
 713    ) -> Vec<(ModelHandle<Buffer>, Range<usize>)> {
 714        let snapshot = self.snapshot(cx);
 715        let start = range.start.to_offset(&snapshot);
 716        let end = range.end.to_offset(&snapshot);
 717
 718        let mut result = Vec::new();
 719        let mut cursor = snapshot.excerpts.cursor::<usize>();
 720        cursor.seek(&start, Bias::Right, &());
 721        while let Some(excerpt) = cursor.item() {
 722            if *cursor.start() > end {
 723                break;
 724            }
 725
 726            let mut end_before_newline = cursor.end(&());
 727            if excerpt.has_trailing_newline {
 728                end_before_newline -= 1;
 729            }
 730            let excerpt_start = excerpt.range.start.to_offset(&excerpt.buffer);
 731            let start = excerpt_start + (cmp::max(start, *cursor.start()) - *cursor.start());
 732            let end = excerpt_start + (cmp::min(end, end_before_newline) - *cursor.start());
 733            let buffer = self.buffers.borrow()[&excerpt.buffer_id].buffer.clone();
 734            result.push((buffer, start..end));
 735            cursor.next(&());
 736        }
 737
 738        result
 739    }
 740
 741    pub fn remove_excerpts<'a>(
 742        &mut self,
 743        excerpt_ids: impl IntoIterator<Item = &'a ExcerptId>,
 744        cx: &mut ModelContext<Self>,
 745    ) {
 746        let mut buffers = self.buffers.borrow_mut();
 747        let mut snapshot = self.snapshot.borrow_mut();
 748        let mut new_excerpts = SumTree::new();
 749        let mut cursor = snapshot.excerpts.cursor::<(Option<&ExcerptId>, usize)>();
 750        let mut edits = Vec::new();
 751        let mut excerpt_ids = excerpt_ids.into_iter().peekable();
 752
 753        while let Some(mut excerpt_id) = excerpt_ids.next() {
 754            // Seek to the next excerpt to remove, preserving any preceding excerpts.
 755            new_excerpts.push_tree(cursor.slice(&Some(excerpt_id), Bias::Left, &()), &());
 756            if let Some(mut excerpt) = cursor.item() {
 757                if excerpt.id != *excerpt_id {
 758                    continue;
 759                }
 760                let mut old_start = cursor.start().1;
 761
 762                // Skip over the removed excerpt.
 763                loop {
 764                    if let Some(buffer_state) = buffers.get_mut(&excerpt.buffer_id) {
 765                        buffer_state.excerpts.retain(|id| id != excerpt_id);
 766                        if buffer_state.excerpts.is_empty() {
 767                            buffers.remove(&excerpt.buffer_id);
 768                        }
 769                    }
 770                    cursor.next(&());
 771
 772                    // Skip over any subsequent excerpts that are also removed.
 773                    if let Some(&next_excerpt_id) = excerpt_ids.peek() {
 774                        if let Some(next_excerpt) = cursor.item() {
 775                            if next_excerpt.id == *next_excerpt_id {
 776                                excerpt = next_excerpt;
 777                                excerpt_id = excerpt_ids.next().unwrap();
 778                                continue;
 779                            }
 780                        }
 781                    }
 782
 783                    break;
 784                }
 785
 786                // When removing the last excerpt, remove the trailing newline from
 787                // the previous excerpt.
 788                if cursor.item().is_none() && old_start > 0 {
 789                    old_start -= 1;
 790                    new_excerpts.update_last(|e| e.has_trailing_newline = false, &());
 791                }
 792
 793                // Push an edit for the removal of this run of excerpts.
 794                let old_end = cursor.start().1;
 795                let new_start = new_excerpts.summary().text.bytes;
 796                edits.push(Edit {
 797                    old: old_start..old_end,
 798                    new: new_start..new_start,
 799                });
 800            }
 801        }
 802        new_excerpts.push_tree(cursor.suffix(&()), &());
 803        drop(cursor);
 804        snapshot.excerpts = new_excerpts;
 805        self.subscriptions.publish_mut(edits);
 806        cx.notify();
 807    }
 808
 809    pub fn text_anchor_for_position<'a, T: ToOffset>(
 810        &'a self,
 811        position: T,
 812        cx: &AppContext,
 813    ) -> (ModelHandle<Buffer>, language::Anchor) {
 814        let snapshot = self.read(cx);
 815        let anchor = snapshot.anchor_before(position);
 816        (
 817            self.buffers.borrow()[&anchor.buffer_id].buffer.clone(),
 818            anchor.text_anchor,
 819        )
 820    }
 821
 822    fn on_buffer_event(
 823        &mut self,
 824        _: ModelHandle<Buffer>,
 825        event: &Event,
 826        cx: &mut ModelContext<Self>,
 827    ) {
 828        cx.emit(event.clone());
 829    }
 830
 831    pub fn format(&mut self, cx: &mut ModelContext<Self>) -> Task<Result<()>> {
 832        let mut format_tasks = Vec::new();
 833        for BufferState { buffer, .. } in self.buffers.borrow().values() {
 834            format_tasks.push(buffer.update(cx, |buffer, cx| buffer.format(cx)));
 835        }
 836
 837        cx.spawn(|_, _| async move {
 838            for format in format_tasks {
 839                format.await?;
 840            }
 841            Ok(())
 842        })
 843    }
 844
 845    pub fn save(&mut self, cx: &mut ModelContext<Self>) -> Task<Result<()>> {
 846        let mut save_tasks = Vec::new();
 847        for BufferState { buffer, .. } in self.buffers.borrow().values() {
 848            save_tasks.push(buffer.update(cx, |buffer, cx| buffer.save(cx)));
 849        }
 850
 851        cx.spawn(|_, _| async move {
 852            for save in save_tasks {
 853                save.await?;
 854            }
 855            Ok(())
 856        })
 857    }
 858
 859    pub fn completions<T>(
 860        &self,
 861        position: T,
 862        cx: &mut ModelContext<Self>,
 863    ) -> Task<Result<Vec<Completion<Anchor>>>>
 864    where
 865        T: ToOffset,
 866    {
 867        let anchor = self.read(cx).anchor_before(position);
 868        let buffer = self.buffers.borrow()[&anchor.buffer_id].buffer.clone();
 869        let completions =
 870            buffer.update(cx, |buffer, cx| buffer.completions(anchor.text_anchor, cx));
 871        cx.spawn(|this, cx| async move {
 872            completions.await.map(|completions| {
 873                let snapshot = this.read_with(&cx, |buffer, cx| buffer.snapshot(cx));
 874                completions
 875                    .into_iter()
 876                    .map(|completion| Completion {
 877                        old_range: snapshot.anchor_in_excerpt(
 878                            anchor.excerpt_id.clone(),
 879                            completion.old_range.start,
 880                        )
 881                            ..snapshot.anchor_in_excerpt(
 882                                anchor.excerpt_id.clone(),
 883                                completion.old_range.end,
 884                            ),
 885                        new_text: completion.new_text,
 886                        lsp_completion: completion.lsp_completion,
 887                    })
 888                    .collect()
 889            })
 890        })
 891    }
 892
 893    pub fn is_completion_trigger<T>(&self, position: T, text: &str, cx: &AppContext) -> bool
 894    where
 895        T: ToOffset,
 896    {
 897        let mut chars = text.chars();
 898        let char = if let Some(char) = chars.next() {
 899            char
 900        } else {
 901            return false;
 902        };
 903        if chars.next().is_some() {
 904            return false;
 905        }
 906
 907        if char.is_alphanumeric() || char == '_' {
 908            return true;
 909        }
 910
 911        let snapshot = self.snapshot(cx);
 912        let anchor = snapshot.anchor_before(position);
 913        let buffer = self.buffers.borrow()[&anchor.buffer_id].buffer.clone();
 914        if let Some(language_server) = buffer.read(cx).language_server() {
 915            language_server
 916                .capabilities()
 917                .completion_provider
 918                .as_ref()
 919                .map_or(false, |provider| {
 920                    provider
 921                        .trigger_characters
 922                        .as_ref()
 923                        .map_or(false, |characters| {
 924                            characters.iter().any(|string| string == text)
 925                        })
 926                })
 927        } else {
 928            false
 929        }
 930    }
 931
 932    pub fn language<'a>(&self, cx: &'a AppContext) -> Option<&'a Arc<Language>> {
 933        self.buffers
 934            .borrow()
 935            .values()
 936            .next()
 937            .and_then(|state| state.buffer.read(cx).language())
 938    }
 939
 940    pub fn file<'a>(&self, cx: &'a AppContext) -> Option<&'a dyn File> {
 941        self.as_singleton()?.read(cx).file()
 942    }
 943
 944    #[cfg(test)]
 945    pub fn is_parsing(&self, cx: &AppContext) -> bool {
 946        self.as_singleton().unwrap().read(cx).is_parsing()
 947    }
 948
 949    fn sync(&self, cx: &AppContext) {
 950        let mut snapshot = self.snapshot.borrow_mut();
 951        let mut excerpts_to_edit = Vec::new();
 952        let mut reparsed = false;
 953        let mut diagnostics_updated = false;
 954        let mut is_dirty = false;
 955        let mut has_conflict = false;
 956        let mut buffers = self.buffers.borrow_mut();
 957        for buffer_state in buffers.values_mut() {
 958            let buffer = buffer_state.buffer.read(cx);
 959            let version = buffer.version();
 960            let parse_count = buffer.parse_count();
 961            let selections_update_count = buffer.selections_update_count();
 962            let diagnostics_update_count = buffer.diagnostics_update_count();
 963
 964            let buffer_edited = version.changed_since(&buffer_state.last_version);
 965            let buffer_reparsed = parse_count > buffer_state.last_parse_count;
 966            let buffer_selections_updated =
 967                selections_update_count > buffer_state.last_selections_update_count;
 968            let buffer_diagnostics_updated =
 969                diagnostics_update_count > buffer_state.last_diagnostics_update_count;
 970            if buffer_edited
 971                || buffer_reparsed
 972                || buffer_selections_updated
 973                || buffer_diagnostics_updated
 974            {
 975                buffer_state.last_version = version;
 976                buffer_state.last_parse_count = parse_count;
 977                buffer_state.last_selections_update_count = selections_update_count;
 978                buffer_state.last_diagnostics_update_count = diagnostics_update_count;
 979                excerpts_to_edit.extend(
 980                    buffer_state
 981                        .excerpts
 982                        .iter()
 983                        .map(|excerpt_id| (excerpt_id, buffer_state.buffer.clone(), buffer_edited)),
 984                );
 985            }
 986
 987            reparsed |= buffer_reparsed;
 988            diagnostics_updated |= buffer_diagnostics_updated;
 989            is_dirty |= buffer.is_dirty();
 990            has_conflict |= buffer.has_conflict();
 991        }
 992        if reparsed {
 993            snapshot.parse_count += 1;
 994        }
 995        if diagnostics_updated {
 996            snapshot.diagnostics_update_count += 1;
 997        }
 998        snapshot.is_dirty = is_dirty;
 999        snapshot.has_conflict = has_conflict;
1000
1001        excerpts_to_edit.sort_unstable_by_key(|(excerpt_id, _, _)| *excerpt_id);
1002
1003        let mut edits = Vec::new();
1004        let mut new_excerpts = SumTree::new();
1005        let mut cursor = snapshot.excerpts.cursor::<(Option<&ExcerptId>, usize)>();
1006
1007        for (id, buffer, buffer_edited) in excerpts_to_edit {
1008            new_excerpts.push_tree(cursor.slice(&Some(id), Bias::Left, &()), &());
1009            let old_excerpt = cursor.item().unwrap();
1010            let buffer_id = buffer.id();
1011            let buffer = buffer.read(cx);
1012
1013            let mut new_excerpt;
1014            if buffer_edited {
1015                edits.extend(
1016                    buffer
1017                        .edits_since_in_range::<usize>(
1018                            old_excerpt.buffer.version(),
1019                            old_excerpt.range.clone(),
1020                        )
1021                        .map(|mut edit| {
1022                            let excerpt_old_start = cursor.start().1;
1023                            let excerpt_new_start = new_excerpts.summary().text.bytes;
1024                            edit.old.start += excerpt_old_start;
1025                            edit.old.end += excerpt_old_start;
1026                            edit.new.start += excerpt_new_start;
1027                            edit.new.end += excerpt_new_start;
1028                            edit
1029                        }),
1030                );
1031
1032                new_excerpt = Excerpt::new(
1033                    id.clone(),
1034                    buffer_id,
1035                    buffer.snapshot(),
1036                    old_excerpt.range.clone(),
1037                    old_excerpt.has_trailing_newline,
1038                );
1039            } else {
1040                new_excerpt = old_excerpt.clone();
1041                new_excerpt.buffer = buffer.snapshot();
1042            }
1043
1044            new_excerpts.push(new_excerpt, &());
1045            cursor.next(&());
1046        }
1047        new_excerpts.push_tree(cursor.suffix(&()), &());
1048
1049        drop(cursor);
1050        snapshot.excerpts = new_excerpts;
1051
1052        self.subscriptions.publish(edits);
1053    }
1054}
1055
1056#[cfg(any(test, feature = "test-support"))]
1057impl MultiBuffer {
1058    pub fn randomly_edit(
1059        &mut self,
1060        rng: &mut impl rand::Rng,
1061        count: usize,
1062        cx: &mut ModelContext<Self>,
1063    ) {
1064        use text::RandomCharIter;
1065
1066        let snapshot = self.read(cx);
1067        let mut old_ranges: Vec<Range<usize>> = Vec::new();
1068        for _ in 0..count {
1069            let last_end = old_ranges.last().map_or(0, |last_range| last_range.end + 1);
1070            if last_end > snapshot.len() {
1071                break;
1072            }
1073            let end_ix = snapshot.clip_offset(rng.gen_range(0..=last_end), Bias::Right);
1074            let start_ix = snapshot.clip_offset(rng.gen_range(0..=end_ix), Bias::Left);
1075            old_ranges.push(start_ix..end_ix);
1076        }
1077        let new_text_len = rng.gen_range(0..10);
1078        let new_text: String = RandomCharIter::new(&mut *rng).take(new_text_len).collect();
1079        log::info!("mutating multi-buffer at {:?}: {:?}", old_ranges, new_text);
1080        drop(snapshot);
1081
1082        self.edit(old_ranges.iter().cloned(), new_text.as_str(), cx);
1083    }
1084}
1085
1086impl Entity for MultiBuffer {
1087    type Event = language::Event;
1088}
1089
1090impl MultiBufferSnapshot {
1091    pub fn text(&self) -> String {
1092        self.chunks(0..self.len(), None)
1093            .map(|chunk| chunk.text)
1094            .collect()
1095    }
1096
1097    pub fn reversed_chars_at<'a, T: ToOffset>(
1098        &'a self,
1099        position: T,
1100    ) -> impl Iterator<Item = char> + 'a {
1101        let mut offset = position.to_offset(self);
1102        let mut cursor = self.excerpts.cursor::<usize>();
1103        cursor.seek(&offset, Bias::Left, &());
1104        let mut excerpt_chunks = cursor.item().map(|excerpt| {
1105            let end_before_footer = cursor.start() + excerpt.text_summary.bytes;
1106            let start = excerpt.range.start.to_offset(&excerpt.buffer);
1107            let end = start + (cmp::min(offset, end_before_footer) - cursor.start());
1108            excerpt.buffer.reversed_chunks_in_range(start..end)
1109        });
1110        iter::from_fn(move || {
1111            if offset == *cursor.start() {
1112                cursor.prev(&());
1113                let excerpt = cursor.item()?;
1114                excerpt_chunks = Some(
1115                    excerpt
1116                        .buffer
1117                        .reversed_chunks_in_range(excerpt.range.clone()),
1118                );
1119            }
1120
1121            let excerpt = cursor.item().unwrap();
1122            if offset == cursor.end(&()) && excerpt.has_trailing_newline {
1123                offset -= 1;
1124                Some("\n")
1125            } else {
1126                let chunk = excerpt_chunks.as_mut().unwrap().next().unwrap();
1127                offset -= chunk.len();
1128                Some(chunk)
1129            }
1130        })
1131        .flat_map(|c| c.chars().rev())
1132    }
1133
1134    pub fn chars_at<'a, T: ToOffset>(&'a self, position: T) -> impl Iterator<Item = char> + 'a {
1135        let offset = position.to_offset(self);
1136        self.text_for_range(offset..self.len())
1137            .flat_map(|chunk| chunk.chars())
1138    }
1139
1140    pub fn text_for_range<'a, T: ToOffset>(
1141        &'a self,
1142        range: Range<T>,
1143    ) -> impl Iterator<Item = &'a str> {
1144        self.chunks(range, None).map(|chunk| chunk.text)
1145    }
1146
1147    pub fn is_line_blank(&self, row: u32) -> bool {
1148        self.text_for_range(Point::new(row, 0)..Point::new(row, self.line_len(row)))
1149            .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
1150    }
1151
1152    pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
1153    where
1154        T: ToOffset,
1155    {
1156        let position = position.to_offset(self);
1157        position == self.clip_offset(position, Bias::Left)
1158            && self
1159                .bytes_in_range(position..self.len())
1160                .flatten()
1161                .copied()
1162                .take(needle.len())
1163                .eq(needle.bytes())
1164    }
1165
1166    pub fn surrounding_word<T: ToOffset>(&self, start: T) -> (Range<usize>, Option<CharKind>) {
1167        let mut start = start.to_offset(self);
1168        let mut end = start;
1169        let mut next_chars = self.chars_at(start).peekable();
1170        let mut prev_chars = self.reversed_chars_at(start).peekable();
1171        let word_kind = cmp::max(
1172            prev_chars.peek().copied().map(char_kind),
1173            next_chars.peek().copied().map(char_kind),
1174        );
1175
1176        for ch in prev_chars {
1177            if Some(char_kind(ch)) == word_kind {
1178                start -= ch.len_utf8();
1179            } else {
1180                break;
1181            }
1182        }
1183
1184        for ch in next_chars {
1185            if Some(char_kind(ch)) == word_kind {
1186                end += ch.len_utf8();
1187            } else {
1188                break;
1189            }
1190        }
1191
1192        (start..end, word_kind)
1193    }
1194
1195    fn as_singleton(&self) -> Option<&Excerpt> {
1196        if self.singleton {
1197            self.excerpts.iter().next()
1198        } else {
1199            None
1200        }
1201    }
1202
1203    pub fn len(&self) -> usize {
1204        self.excerpts.summary().text.bytes
1205    }
1206
1207    pub fn max_buffer_row(&self) -> u32 {
1208        self.excerpts.summary().max_buffer_row
1209    }
1210
1211    pub fn clip_offset(&self, offset: usize, bias: Bias) -> usize {
1212        if let Some(excerpt) = self.as_singleton() {
1213            return excerpt.buffer.clip_offset(offset, bias);
1214        }
1215
1216        let mut cursor = self.excerpts.cursor::<usize>();
1217        cursor.seek(&offset, Bias::Right, &());
1218        let overshoot = if let Some(excerpt) = cursor.item() {
1219            let excerpt_start = excerpt.range.start.to_offset(&excerpt.buffer);
1220            let buffer_offset = excerpt
1221                .buffer
1222                .clip_offset(excerpt_start + (offset - cursor.start()), bias);
1223            buffer_offset.saturating_sub(excerpt_start)
1224        } else {
1225            0
1226        };
1227        cursor.start() + overshoot
1228    }
1229
1230    pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
1231        if let Some(excerpt) = self.as_singleton() {
1232            return excerpt.buffer.clip_point(point, bias);
1233        }
1234
1235        let mut cursor = self.excerpts.cursor::<Point>();
1236        cursor.seek(&point, Bias::Right, &());
1237        let overshoot = if let Some(excerpt) = cursor.item() {
1238            let excerpt_start = excerpt.range.start.to_point(&excerpt.buffer);
1239            let buffer_point = excerpt
1240                .buffer
1241                .clip_point(excerpt_start + (point - cursor.start()), bias);
1242            buffer_point.saturating_sub(excerpt_start)
1243        } else {
1244            Point::zero()
1245        };
1246        *cursor.start() + overshoot
1247    }
1248
1249    pub fn clip_point_utf16(&self, point: PointUtf16, bias: Bias) -> PointUtf16 {
1250        if let Some(excerpt) = self.as_singleton() {
1251            return excerpt.buffer.clip_point_utf16(point, bias);
1252        }
1253
1254        let mut cursor = self.excerpts.cursor::<PointUtf16>();
1255        cursor.seek(&point, Bias::Right, &());
1256        let overshoot = if let Some(excerpt) = cursor.item() {
1257            let excerpt_start = excerpt
1258                .buffer
1259                .offset_to_point_utf16(excerpt.range.start.to_offset(&excerpt.buffer));
1260            let buffer_point = excerpt
1261                .buffer
1262                .clip_point_utf16(excerpt_start + (point - cursor.start()), bias);
1263            buffer_point.saturating_sub(excerpt_start)
1264        } else {
1265            PointUtf16::zero()
1266        };
1267        *cursor.start() + overshoot
1268    }
1269
1270    pub fn bytes_in_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> MultiBufferBytes<'a> {
1271        let range = range.start.to_offset(self)..range.end.to_offset(self);
1272        let mut excerpts = self.excerpts.cursor::<usize>();
1273        excerpts.seek(&range.start, Bias::Right, &());
1274
1275        let mut chunk = &[][..];
1276        let excerpt_bytes = if let Some(excerpt) = excerpts.item() {
1277            let mut excerpt_bytes = excerpt
1278                .bytes_in_range(range.start - excerpts.start()..range.end - excerpts.start());
1279            chunk = excerpt_bytes.next().unwrap_or(&[][..]);
1280            Some(excerpt_bytes)
1281        } else {
1282            None
1283        };
1284
1285        MultiBufferBytes {
1286            range,
1287            excerpts,
1288            excerpt_bytes,
1289            chunk,
1290        }
1291    }
1292
1293    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> MultiBufferRows<'a> {
1294        let mut result = MultiBufferRows {
1295            buffer_row_range: 0..0,
1296            excerpts: self.excerpts.cursor(),
1297        };
1298        result.seek(start_row);
1299        result
1300    }
1301
1302    pub fn chunks<'a, T: ToOffset>(
1303        &'a self,
1304        range: Range<T>,
1305        theme: Option<&'a SyntaxTheme>,
1306    ) -> MultiBufferChunks<'a> {
1307        let range = range.start.to_offset(self)..range.end.to_offset(self);
1308        let mut chunks = MultiBufferChunks {
1309            range: range.clone(),
1310            excerpts: self.excerpts.cursor(),
1311            excerpt_chunks: None,
1312            theme,
1313        };
1314        chunks.seek(range.start);
1315        chunks
1316    }
1317
1318    pub fn offset_to_point(&self, offset: usize) -> Point {
1319        if let Some(excerpt) = self.as_singleton() {
1320            return excerpt.buffer.offset_to_point(offset);
1321        }
1322
1323        let mut cursor = self.excerpts.cursor::<(usize, Point)>();
1324        cursor.seek(&offset, Bias::Right, &());
1325        if let Some(excerpt) = cursor.item() {
1326            let (start_offset, start_point) = cursor.start();
1327            let overshoot = offset - start_offset;
1328            let excerpt_start_offset = excerpt.range.start.to_offset(&excerpt.buffer);
1329            let excerpt_start_point = excerpt.range.start.to_point(&excerpt.buffer);
1330            let buffer_point = excerpt
1331                .buffer
1332                .offset_to_point(excerpt_start_offset + overshoot);
1333            *start_point + (buffer_point - excerpt_start_point)
1334        } else {
1335            self.excerpts.summary().text.lines
1336        }
1337    }
1338
1339    pub fn point_to_offset(&self, point: Point) -> usize {
1340        if let Some(excerpt) = self.as_singleton() {
1341            return excerpt.buffer.point_to_offset(point);
1342        }
1343
1344        let mut cursor = self.excerpts.cursor::<(Point, usize)>();
1345        cursor.seek(&point, Bias::Right, &());
1346        if let Some(excerpt) = cursor.item() {
1347            let (start_point, start_offset) = cursor.start();
1348            let overshoot = point - start_point;
1349            let excerpt_start_offset = excerpt.range.start.to_offset(&excerpt.buffer);
1350            let excerpt_start_point = excerpt.range.start.to_point(&excerpt.buffer);
1351            let buffer_offset = excerpt
1352                .buffer
1353                .point_to_offset(excerpt_start_point + overshoot);
1354            *start_offset + buffer_offset - excerpt_start_offset
1355        } else {
1356            self.excerpts.summary().text.bytes
1357        }
1358    }
1359
1360    pub fn point_utf16_to_offset(&self, point: PointUtf16) -> usize {
1361        if let Some(excerpt) = self.as_singleton() {
1362            return excerpt.buffer.point_utf16_to_offset(point);
1363        }
1364
1365        let mut cursor = self.excerpts.cursor::<(PointUtf16, usize)>();
1366        cursor.seek(&point, Bias::Right, &());
1367        if let Some(excerpt) = cursor.item() {
1368            let (start_point, start_offset) = cursor.start();
1369            let overshoot = point - start_point;
1370            let excerpt_start_offset = excerpt.range.start.to_offset(&excerpt.buffer);
1371            let excerpt_start_point = excerpt
1372                .buffer
1373                .offset_to_point_utf16(excerpt.range.start.to_offset(&excerpt.buffer));
1374            let buffer_offset = excerpt
1375                .buffer
1376                .point_utf16_to_offset(excerpt_start_point + overshoot);
1377            *start_offset + (buffer_offset - excerpt_start_offset)
1378        } else {
1379            self.excerpts.summary().text.bytes
1380        }
1381    }
1382
1383    pub fn indent_column_for_line(&self, row: u32) -> u32 {
1384        if let Some((buffer, range)) = self.buffer_line_for_row(row) {
1385            buffer
1386                .indent_column_for_line(range.start.row)
1387                .min(range.end.column)
1388                .saturating_sub(range.start.column)
1389        } else {
1390            0
1391        }
1392    }
1393
1394    pub fn line_len(&self, row: u32) -> u32 {
1395        if let Some((_, range)) = self.buffer_line_for_row(row) {
1396            range.end.column - range.start.column
1397        } else {
1398            0
1399        }
1400    }
1401
1402    fn buffer_line_for_row(&self, row: u32) -> Option<(&BufferSnapshot, Range<Point>)> {
1403        let mut cursor = self.excerpts.cursor::<Point>();
1404        cursor.seek(&Point::new(row, 0), Bias::Right, &());
1405        if let Some(excerpt) = cursor.item() {
1406            let overshoot = row - cursor.start().row;
1407            let excerpt_start = excerpt.range.start.to_point(&excerpt.buffer);
1408            let excerpt_end = excerpt.range.end.to_point(&excerpt.buffer);
1409            let buffer_row = excerpt_start.row + overshoot;
1410            let line_start = Point::new(buffer_row, 0);
1411            let line_end = Point::new(buffer_row, excerpt.buffer.line_len(buffer_row));
1412            return Some((
1413                &excerpt.buffer,
1414                line_start.max(excerpt_start)..line_end.min(excerpt_end),
1415            ));
1416        }
1417        None
1418    }
1419
1420    pub fn max_point(&self) -> Point {
1421        self.text_summary().lines
1422    }
1423
1424    pub fn text_summary(&self) -> TextSummary {
1425        self.excerpts.summary().text
1426    }
1427
1428    pub fn text_summary_for_range<'a, D, O>(&'a self, range: Range<O>) -> D
1429    where
1430        D: TextDimension,
1431        O: ToOffset,
1432    {
1433        let mut summary = D::default();
1434        let mut range = range.start.to_offset(self)..range.end.to_offset(self);
1435        let mut cursor = self.excerpts.cursor::<usize>();
1436        cursor.seek(&range.start, Bias::Right, &());
1437        if let Some(excerpt) = cursor.item() {
1438            let mut end_before_newline = cursor.end(&());
1439            if excerpt.has_trailing_newline {
1440                end_before_newline -= 1;
1441            }
1442
1443            let excerpt_start = excerpt.range.start.to_offset(&excerpt.buffer);
1444            let start_in_excerpt = excerpt_start + (range.start - cursor.start());
1445            let end_in_excerpt =
1446                excerpt_start + (cmp::min(end_before_newline, range.end) - cursor.start());
1447            summary.add_assign(
1448                &excerpt
1449                    .buffer
1450                    .text_summary_for_range(start_in_excerpt..end_in_excerpt),
1451            );
1452
1453            if range.end > end_before_newline {
1454                summary.add_assign(&D::from_text_summary(&TextSummary {
1455                    bytes: 1,
1456                    lines: Point::new(1 as u32, 0),
1457                    lines_utf16: PointUtf16::new(1 as u32, 0),
1458                    first_line_chars: 0,
1459                    last_line_chars: 0,
1460                    longest_row: 0,
1461                    longest_row_chars: 0,
1462                }));
1463            }
1464
1465            cursor.next(&());
1466        }
1467
1468        if range.end > *cursor.start() {
1469            summary.add_assign(&D::from_text_summary(&cursor.summary::<_, TextSummary>(
1470                &range.end,
1471                Bias::Right,
1472                &(),
1473            )));
1474            if let Some(excerpt) = cursor.item() {
1475                range.end = cmp::max(*cursor.start(), range.end);
1476
1477                let excerpt_start = excerpt.range.start.to_offset(&excerpt.buffer);
1478                let end_in_excerpt = excerpt_start + (range.end - cursor.start());
1479                summary.add_assign(
1480                    &excerpt
1481                        .buffer
1482                        .text_summary_for_range(excerpt_start..end_in_excerpt),
1483                );
1484            }
1485        }
1486
1487        summary
1488    }
1489
1490    pub fn summary_for_anchor<D>(&self, anchor: &Anchor) -> D
1491    where
1492        D: TextDimension + Ord + Sub<D, Output = D>,
1493    {
1494        let mut cursor = self.excerpts.cursor::<ExcerptSummary>();
1495        cursor.seek(&Some(&anchor.excerpt_id), Bias::Left, &());
1496        if cursor.item().is_none() {
1497            cursor.next(&());
1498        }
1499
1500        let mut position = D::from_text_summary(&cursor.start().text);
1501        if let Some(excerpt) = cursor.item() {
1502            if excerpt.id == anchor.excerpt_id && excerpt.buffer_id == anchor.buffer_id {
1503                let excerpt_buffer_start = excerpt.range.start.summary::<D>(&excerpt.buffer);
1504                let excerpt_buffer_end = excerpt.range.end.summary::<D>(&excerpt.buffer);
1505                let buffer_position = cmp::min(
1506                    excerpt_buffer_end,
1507                    anchor.text_anchor.summary::<D>(&excerpt.buffer),
1508                );
1509                if buffer_position > excerpt_buffer_start {
1510                    position.add_assign(&(buffer_position - excerpt_buffer_start));
1511                }
1512            }
1513        }
1514        position
1515    }
1516
1517    pub fn summaries_for_anchors<'a, D, I>(&'a self, anchors: I) -> Vec<D>
1518    where
1519        D: TextDimension + Ord + Sub<D, Output = D>,
1520        I: 'a + IntoIterator<Item = &'a Anchor>,
1521    {
1522        let mut anchors = anchors.into_iter().peekable();
1523        let mut cursor = self.excerpts.cursor::<ExcerptSummary>();
1524        let mut summaries = Vec::new();
1525        while let Some(anchor) = anchors.peek() {
1526            let excerpt_id = &anchor.excerpt_id;
1527            let buffer_id = anchor.buffer_id;
1528            let excerpt_anchors = iter::from_fn(|| {
1529                let anchor = anchors.peek()?;
1530                if anchor.excerpt_id == *excerpt_id && anchor.buffer_id == buffer_id {
1531                    Some(&anchors.next().unwrap().text_anchor)
1532                } else {
1533                    None
1534                }
1535            });
1536
1537            cursor.seek_forward(&Some(excerpt_id), Bias::Left, &());
1538            if cursor.item().is_none() {
1539                cursor.next(&());
1540            }
1541
1542            let position = D::from_text_summary(&cursor.start().text);
1543            if let Some(excerpt) = cursor.item() {
1544                if excerpt.id == *excerpt_id && excerpt.buffer_id == buffer_id {
1545                    let excerpt_buffer_start = excerpt.range.start.summary::<D>(&excerpt.buffer);
1546                    let excerpt_buffer_end = excerpt.range.end.summary::<D>(&excerpt.buffer);
1547                    summaries.extend(
1548                        excerpt
1549                            .buffer
1550                            .summaries_for_anchors::<D, _>(excerpt_anchors)
1551                            .map(move |summary| {
1552                                let summary = cmp::min(excerpt_buffer_end.clone(), summary);
1553                                let mut position = position.clone();
1554                                let excerpt_buffer_start = excerpt_buffer_start.clone();
1555                                if summary > excerpt_buffer_start {
1556                                    position.add_assign(&(summary - excerpt_buffer_start));
1557                                }
1558                                position
1559                            }),
1560                    );
1561                    continue;
1562                }
1563            }
1564
1565            summaries.extend(excerpt_anchors.map(|_| position.clone()));
1566        }
1567
1568        summaries
1569    }
1570
1571    pub fn refresh_anchors<'a, I>(&'a self, anchors: I) -> Vec<(usize, Anchor, bool)>
1572    where
1573        I: 'a + IntoIterator<Item = &'a Anchor>,
1574    {
1575        let mut anchors = anchors.into_iter().enumerate().peekable();
1576        let mut cursor = self.excerpts.cursor::<Option<&ExcerptId>>();
1577        let mut result = Vec::new();
1578        while let Some((_, anchor)) = anchors.peek() {
1579            let old_excerpt_id = &anchor.excerpt_id;
1580
1581            // Find the location where this anchor's excerpt should be.
1582            cursor.seek_forward(&Some(old_excerpt_id), Bias::Left, &());
1583            if cursor.item().is_none() {
1584                cursor.next(&());
1585            }
1586
1587            let next_excerpt = cursor.item();
1588            let prev_excerpt = cursor.prev_item();
1589
1590            // Process all of the anchors for this excerpt.
1591            while let Some((_, anchor)) = anchors.peek() {
1592                if anchor.excerpt_id != *old_excerpt_id {
1593                    break;
1594                }
1595                let mut kept_position = false;
1596                let (anchor_ix, anchor) = anchors.next().unwrap();
1597                let mut anchor = anchor.clone();
1598
1599                // Leave min and max anchors unchanged.
1600                if *old_excerpt_id == ExcerptId::max() || *old_excerpt_id == ExcerptId::min() {
1601                    kept_position = true;
1602                }
1603                // If the old excerpt still exists at this location, then leave
1604                // the anchor unchanged.
1605                else if next_excerpt.map_or(false, |excerpt| {
1606                    excerpt.id == *old_excerpt_id && excerpt.contains(&anchor)
1607                }) {
1608                    kept_position = true;
1609                }
1610                // If the old excerpt no longer exists at this location, then attempt to
1611                // find an equivalent position for this anchor in an adjacent excerpt.
1612                else {
1613                    for excerpt in [next_excerpt, prev_excerpt].iter().filter_map(|e| *e) {
1614                        if excerpt.contains(&anchor) {
1615                            anchor.excerpt_id = excerpt.id.clone();
1616                            kept_position = true;
1617                            break;
1618                        }
1619                    }
1620                }
1621                // If there's no adjacent excerpt that contains the anchor's position,
1622                // then report that the anchor has lost its position.
1623                if !kept_position {
1624                    anchor = if let Some(excerpt) = next_excerpt {
1625                        let mut text_anchor = excerpt
1626                            .range
1627                            .start
1628                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
1629                        if text_anchor
1630                            .cmp(&excerpt.range.end, &excerpt.buffer)
1631                            .unwrap()
1632                            .is_gt()
1633                        {
1634                            text_anchor = excerpt.range.end.clone();
1635                        }
1636                        Anchor {
1637                            buffer_id: excerpt.buffer_id,
1638                            excerpt_id: excerpt.id.clone(),
1639                            text_anchor,
1640                        }
1641                    } else if let Some(excerpt) = prev_excerpt {
1642                        let mut text_anchor = excerpt
1643                            .range
1644                            .end
1645                            .bias(anchor.text_anchor.bias, &excerpt.buffer);
1646                        if text_anchor
1647                            .cmp(&excerpt.range.start, &excerpt.buffer)
1648                            .unwrap()
1649                            .is_lt()
1650                        {
1651                            text_anchor = excerpt.range.start.clone();
1652                        }
1653                        Anchor {
1654                            buffer_id: excerpt.buffer_id,
1655                            excerpt_id: excerpt.id.clone(),
1656                            text_anchor,
1657                        }
1658                    } else if anchor.text_anchor.bias == Bias::Left {
1659                        Anchor::min()
1660                    } else {
1661                        Anchor::max()
1662                    };
1663                }
1664
1665                result.push((anchor_ix, anchor, kept_position));
1666            }
1667        }
1668        result.sort_unstable_by(|a, b| a.1.cmp(&b.1, self).unwrap());
1669        result
1670    }
1671
1672    pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
1673        self.anchor_at(position, Bias::Left)
1674    }
1675
1676    pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
1677        self.anchor_at(position, Bias::Right)
1678    }
1679
1680    pub fn anchor_at<T: ToOffset>(&self, position: T, mut bias: Bias) -> Anchor {
1681        let offset = position.to_offset(self);
1682        if let Some(excerpt) = self.as_singleton() {
1683            return Anchor {
1684                buffer_id: excerpt.buffer_id,
1685                excerpt_id: excerpt.id.clone(),
1686                text_anchor: excerpt.buffer.anchor_at(offset, bias),
1687            };
1688        }
1689
1690        let mut cursor = self.excerpts.cursor::<(usize, Option<&ExcerptId>)>();
1691        cursor.seek(&offset, Bias::Right, &());
1692        if cursor.item().is_none() && offset == cursor.start().0 && bias == Bias::Left {
1693            cursor.prev(&());
1694        }
1695        if let Some(excerpt) = cursor.item() {
1696            let mut overshoot = offset.saturating_sub(cursor.start().0);
1697            if excerpt.has_trailing_newline && offset == cursor.end(&()).0 {
1698                overshoot -= 1;
1699                bias = Bias::Right;
1700            }
1701
1702            let buffer_start = excerpt.range.start.to_offset(&excerpt.buffer);
1703            let text_anchor =
1704                excerpt.clip_anchor(excerpt.buffer.anchor_at(buffer_start + overshoot, bias));
1705            Anchor {
1706                buffer_id: excerpt.buffer_id,
1707                excerpt_id: excerpt.id.clone(),
1708                text_anchor,
1709            }
1710        } else if offset == 0 && bias == Bias::Left {
1711            Anchor::min()
1712        } else {
1713            Anchor::max()
1714        }
1715    }
1716
1717    pub fn anchor_in_excerpt(&self, excerpt_id: ExcerptId, text_anchor: text::Anchor) -> Anchor {
1718        let mut cursor = self.excerpts.cursor::<Option<&ExcerptId>>();
1719        cursor.seek(&Some(&excerpt_id), Bias::Left, &());
1720        if let Some(excerpt) = cursor.item() {
1721            if excerpt.id == excerpt_id {
1722                let text_anchor = excerpt.clip_anchor(text_anchor);
1723                drop(cursor);
1724                return Anchor {
1725                    buffer_id: excerpt.buffer_id,
1726                    excerpt_id,
1727                    text_anchor,
1728                };
1729            }
1730        }
1731        panic!("excerpt not found");
1732    }
1733
1734    pub fn can_resolve(&self, anchor: &Anchor) -> bool {
1735        if anchor.excerpt_id == ExcerptId::min() || anchor.excerpt_id == ExcerptId::max() {
1736            true
1737        } else if let Some((buffer_id, buffer_snapshot)) =
1738            self.buffer_snapshot_for_excerpt(&anchor.excerpt_id)
1739        {
1740            anchor.buffer_id == buffer_id && buffer_snapshot.can_resolve(&anchor.text_anchor)
1741        } else {
1742            false
1743        }
1744    }
1745
1746    pub fn range_contains_excerpt_boundary<T: ToOffset>(&self, range: Range<T>) -> bool {
1747        let start = range.start.to_offset(self);
1748        let end = range.end.to_offset(self);
1749        let mut cursor = self.excerpts.cursor::<(usize, Option<&ExcerptId>)>();
1750        cursor.seek(&start, Bias::Right, &());
1751        let start_id = cursor
1752            .item()
1753            .or_else(|| cursor.prev_item())
1754            .map(|excerpt| &excerpt.id);
1755        cursor.seek_forward(&end, Bias::Right, &());
1756        let end_id = cursor
1757            .item()
1758            .or_else(|| cursor.prev_item())
1759            .map(|excerpt| &excerpt.id);
1760        start_id != end_id
1761    }
1762
1763    pub fn parse_count(&self) -> usize {
1764        self.parse_count
1765    }
1766
1767    pub fn enclosing_bracket_ranges<T: ToOffset>(
1768        &self,
1769        range: Range<T>,
1770    ) -> Option<(Range<usize>, Range<usize>)> {
1771        let range = range.start.to_offset(self)..range.end.to_offset(self);
1772
1773        let mut cursor = self.excerpts.cursor::<usize>();
1774        cursor.seek(&range.start, Bias::Right, &());
1775        let start_excerpt = cursor.item();
1776
1777        cursor.seek(&range.end, Bias::Right, &());
1778        let end_excerpt = cursor.item();
1779
1780        start_excerpt
1781            .zip(end_excerpt)
1782            .and_then(|(start_excerpt, end_excerpt)| {
1783                if start_excerpt.id != end_excerpt.id {
1784                    return None;
1785                }
1786
1787                let excerpt_buffer_start =
1788                    start_excerpt.range.start.to_offset(&start_excerpt.buffer);
1789                let excerpt_buffer_end = excerpt_buffer_start + start_excerpt.text_summary.bytes;
1790
1791                let start_in_buffer =
1792                    excerpt_buffer_start + range.start.saturating_sub(*cursor.start());
1793                let end_in_buffer =
1794                    excerpt_buffer_start + range.end.saturating_sub(*cursor.start());
1795                let (mut start_bracket_range, mut end_bracket_range) = start_excerpt
1796                    .buffer
1797                    .enclosing_bracket_ranges(start_in_buffer..end_in_buffer)?;
1798
1799                if start_bracket_range.start >= excerpt_buffer_start
1800                    && end_bracket_range.end < excerpt_buffer_end
1801                {
1802                    start_bracket_range.start =
1803                        cursor.start() + (start_bracket_range.start - excerpt_buffer_start);
1804                    start_bracket_range.end =
1805                        cursor.start() + (start_bracket_range.end - excerpt_buffer_start);
1806                    end_bracket_range.start =
1807                        cursor.start() + (end_bracket_range.start - excerpt_buffer_start);
1808                    end_bracket_range.end =
1809                        cursor.start() + (end_bracket_range.end - excerpt_buffer_start);
1810                    Some((start_bracket_range, end_bracket_range))
1811                } else {
1812                    None
1813                }
1814            })
1815    }
1816
1817    pub fn diagnostics_update_count(&self) -> usize {
1818        self.diagnostics_update_count
1819    }
1820
1821    pub fn language(&self) -> Option<&Arc<Language>> {
1822        self.excerpts
1823            .iter()
1824            .next()
1825            .and_then(|excerpt| excerpt.buffer.language())
1826    }
1827
1828    pub fn is_dirty(&self) -> bool {
1829        self.is_dirty
1830    }
1831
1832    pub fn has_conflict(&self) -> bool {
1833        self.has_conflict
1834    }
1835
1836    pub fn diagnostic_group<'a, O>(
1837        &'a self,
1838        group_id: usize,
1839    ) -> impl Iterator<Item = DiagnosticEntry<O>> + 'a
1840    where
1841        O: text::FromAnchor + 'a,
1842    {
1843        self.as_singleton()
1844            .into_iter()
1845            .flat_map(move |excerpt| excerpt.buffer.diagnostic_group(group_id))
1846    }
1847
1848    pub fn diagnostics_in_range<'a, T, O>(
1849        &'a self,
1850        range: Range<T>,
1851    ) -> impl Iterator<Item = DiagnosticEntry<O>> + 'a
1852    where
1853        T: 'a + ToOffset,
1854        O: 'a + text::FromAnchor,
1855    {
1856        self.as_singleton().into_iter().flat_map(move |excerpt| {
1857            excerpt
1858                .buffer
1859                .diagnostics_in_range(range.start.to_offset(self)..range.end.to_offset(self))
1860        })
1861    }
1862
1863    pub fn range_for_syntax_ancestor<T: ToOffset>(&self, range: Range<T>) -> Option<Range<usize>> {
1864        let range = range.start.to_offset(self)..range.end.to_offset(self);
1865
1866        let mut cursor = self.excerpts.cursor::<usize>();
1867        cursor.seek(&range.start, Bias::Right, &());
1868        let start_excerpt = cursor.item();
1869
1870        cursor.seek(&range.end, Bias::Right, &());
1871        let end_excerpt = cursor.item();
1872
1873        start_excerpt
1874            .zip(end_excerpt)
1875            .and_then(|(start_excerpt, end_excerpt)| {
1876                if start_excerpt.id != end_excerpt.id {
1877                    return None;
1878                }
1879
1880                let excerpt_buffer_start =
1881                    start_excerpt.range.start.to_offset(&start_excerpt.buffer);
1882                let excerpt_buffer_end = excerpt_buffer_start + start_excerpt.text_summary.bytes;
1883
1884                let start_in_buffer =
1885                    excerpt_buffer_start + range.start.saturating_sub(*cursor.start());
1886                let end_in_buffer =
1887                    excerpt_buffer_start + range.end.saturating_sub(*cursor.start());
1888                let mut ancestor_buffer_range = start_excerpt
1889                    .buffer
1890                    .range_for_syntax_ancestor(start_in_buffer..end_in_buffer)?;
1891                ancestor_buffer_range.start =
1892                    cmp::max(ancestor_buffer_range.start, excerpt_buffer_start);
1893                ancestor_buffer_range.end = cmp::min(ancestor_buffer_range.end, excerpt_buffer_end);
1894
1895                let start = cursor.start() + (ancestor_buffer_range.start - excerpt_buffer_start);
1896                let end = cursor.start() + (ancestor_buffer_range.end - excerpt_buffer_start);
1897                Some(start..end)
1898            })
1899    }
1900
1901    pub fn outline(&self, theme: Option<&SyntaxTheme>) -> Option<Outline<Anchor>> {
1902        let excerpt = self.as_singleton()?;
1903        let outline = excerpt.buffer.outline(theme)?;
1904        Some(Outline::new(
1905            outline
1906                .items
1907                .into_iter()
1908                .map(|item| OutlineItem {
1909                    depth: item.depth,
1910                    range: self.anchor_in_excerpt(excerpt.id.clone(), item.range.start)
1911                        ..self.anchor_in_excerpt(excerpt.id.clone(), item.range.end),
1912                    text: item.text,
1913                    highlight_ranges: item.highlight_ranges,
1914                    name_ranges: item.name_ranges,
1915                })
1916                .collect(),
1917        ))
1918    }
1919
1920    fn buffer_snapshot_for_excerpt<'a>(
1921        &'a self,
1922        excerpt_id: &'a ExcerptId,
1923    ) -> Option<(usize, &'a BufferSnapshot)> {
1924        let mut cursor = self.excerpts.cursor::<Option<&ExcerptId>>();
1925        cursor.seek(&Some(excerpt_id), Bias::Left, &());
1926        if let Some(excerpt) = cursor.item() {
1927            if excerpt.id == *excerpt_id {
1928                return Some((excerpt.buffer_id, &excerpt.buffer));
1929            }
1930        }
1931        None
1932    }
1933
1934    pub fn remote_selections_in_range<'a>(
1935        &'a self,
1936        range: &'a Range<Anchor>,
1937    ) -> impl 'a + Iterator<Item = (ReplicaId, Selection<Anchor>)> {
1938        let mut cursor = self.excerpts.cursor::<Option<&ExcerptId>>();
1939        cursor.seek(&Some(&range.start.excerpt_id), Bias::Left, &());
1940        cursor
1941            .take_while(move |excerpt| excerpt.id <= range.end.excerpt_id)
1942            .flat_map(move |excerpt| {
1943                let mut query_range = excerpt.range.start.clone()..excerpt.range.end.clone();
1944                if excerpt.id == range.start.excerpt_id {
1945                    query_range.start = range.start.text_anchor.clone();
1946                }
1947                if excerpt.id == range.end.excerpt_id {
1948                    query_range.end = range.end.text_anchor.clone();
1949                }
1950
1951                excerpt
1952                    .buffer
1953                    .remote_selections_in_range(query_range)
1954                    .flat_map(move |(replica_id, selections)| {
1955                        selections.map(move |selection| {
1956                            let mut start = Anchor {
1957                                buffer_id: excerpt.buffer_id,
1958                                excerpt_id: excerpt.id.clone(),
1959                                text_anchor: selection.start.clone(),
1960                            };
1961                            let mut end = Anchor {
1962                                buffer_id: excerpt.buffer_id,
1963                                excerpt_id: excerpt.id.clone(),
1964                                text_anchor: selection.end.clone(),
1965                            };
1966                            if range.start.cmp(&start, self).unwrap().is_gt() {
1967                                start = range.start.clone();
1968                            }
1969                            if range.end.cmp(&end, self).unwrap().is_lt() {
1970                                end = range.end.clone();
1971                            }
1972
1973                            (
1974                                replica_id,
1975                                Selection {
1976                                    id: selection.id,
1977                                    start,
1978                                    end,
1979                                    reversed: selection.reversed,
1980                                    goal: selection.goal,
1981                                },
1982                            )
1983                        })
1984                    })
1985            })
1986    }
1987}
1988
1989impl History {
1990    fn start_transaction(&mut self, now: Instant) -> Option<TransactionId> {
1991        self.transaction_depth += 1;
1992        if self.transaction_depth == 1 {
1993            let id = post_inc(&mut self.next_transaction_id);
1994            self.undo_stack.push(Transaction {
1995                id,
1996                buffer_transactions: Default::default(),
1997                first_edit_at: now,
1998                last_edit_at: now,
1999            });
2000            Some(id)
2001        } else {
2002            None
2003        }
2004    }
2005
2006    fn end_transaction(
2007        &mut self,
2008        now: Instant,
2009        buffer_transactions: HashSet<(usize, TransactionId)>,
2010    ) -> bool {
2011        assert_ne!(self.transaction_depth, 0);
2012        self.transaction_depth -= 1;
2013        if self.transaction_depth == 0 {
2014            if buffer_transactions.is_empty() {
2015                self.undo_stack.pop();
2016                false
2017            } else {
2018                let transaction = self.undo_stack.last_mut().unwrap();
2019                transaction.last_edit_at = now;
2020                transaction.buffer_transactions.extend(buffer_transactions);
2021                true
2022            }
2023        } else {
2024            false
2025        }
2026    }
2027
2028    fn pop_undo(&mut self) -> Option<&Transaction> {
2029        assert_eq!(self.transaction_depth, 0);
2030        if let Some(transaction) = self.undo_stack.pop() {
2031            self.redo_stack.push(transaction);
2032            self.redo_stack.last()
2033        } else {
2034            None
2035        }
2036    }
2037
2038    fn pop_redo(&mut self) -> Option<&Transaction> {
2039        assert_eq!(self.transaction_depth, 0);
2040        if let Some(transaction) = self.redo_stack.pop() {
2041            self.undo_stack.push(transaction);
2042            self.undo_stack.last()
2043        } else {
2044            None
2045        }
2046    }
2047
2048    fn group(&mut self) -> Option<TransactionId> {
2049        let mut new_len = self.undo_stack.len();
2050        let mut transactions = self.undo_stack.iter_mut();
2051
2052        if let Some(mut transaction) = transactions.next_back() {
2053            while let Some(prev_transaction) = transactions.next_back() {
2054                if transaction.first_edit_at - prev_transaction.last_edit_at <= self.group_interval
2055                {
2056                    transaction = prev_transaction;
2057                    new_len -= 1;
2058                } else {
2059                    break;
2060                }
2061            }
2062        }
2063
2064        let (transactions_to_keep, transactions_to_merge) = self.undo_stack.split_at_mut(new_len);
2065        if let Some(last_transaction) = transactions_to_keep.last_mut() {
2066            if let Some(transaction) = transactions_to_merge.last() {
2067                last_transaction.last_edit_at = transaction.last_edit_at;
2068            }
2069        }
2070
2071        self.undo_stack.truncate(new_len);
2072        self.undo_stack.last().map(|t| t.id)
2073    }
2074}
2075
2076impl Excerpt {
2077    fn new(
2078        id: ExcerptId,
2079        buffer_id: usize,
2080        buffer: BufferSnapshot,
2081        range: Range<text::Anchor>,
2082        has_trailing_newline: bool,
2083    ) -> Self {
2084        Excerpt {
2085            id,
2086            max_buffer_row: range.end.to_point(&buffer).row,
2087            text_summary: buffer.text_summary_for_range::<TextSummary, _>(range.to_offset(&buffer)),
2088            buffer_id,
2089            buffer,
2090            range,
2091            has_trailing_newline,
2092        }
2093    }
2094
2095    fn chunks_in_range<'a>(
2096        &'a self,
2097        range: Range<usize>,
2098        theme: Option<&'a SyntaxTheme>,
2099    ) -> ExcerptChunks<'a> {
2100        let content_start = self.range.start.to_offset(&self.buffer);
2101        let chunks_start = content_start + range.start;
2102        let chunks_end = content_start + cmp::min(range.end, self.text_summary.bytes);
2103
2104        let footer_height = if self.has_trailing_newline
2105            && range.start <= self.text_summary.bytes
2106            && range.end > self.text_summary.bytes
2107        {
2108            1
2109        } else {
2110            0
2111        };
2112
2113        let content_chunks = self.buffer.chunks(chunks_start..chunks_end, theme);
2114
2115        ExcerptChunks {
2116            content_chunks,
2117            footer_height,
2118        }
2119    }
2120
2121    fn bytes_in_range(&self, range: Range<usize>) -> ExcerptBytes {
2122        let content_start = self.range.start.to_offset(&self.buffer);
2123        let bytes_start = content_start + range.start;
2124        let bytes_end = content_start + cmp::min(range.end, self.text_summary.bytes);
2125        let footer_height = if self.has_trailing_newline
2126            && range.start <= self.text_summary.bytes
2127            && range.end > self.text_summary.bytes
2128        {
2129            1
2130        } else {
2131            0
2132        };
2133        let content_bytes = self.buffer.bytes_in_range(bytes_start..bytes_end);
2134
2135        ExcerptBytes {
2136            content_bytes,
2137            footer_height,
2138        }
2139    }
2140
2141    fn clip_anchor(&self, text_anchor: text::Anchor) -> text::Anchor {
2142        if text_anchor
2143            .cmp(&self.range.start, &self.buffer)
2144            .unwrap()
2145            .is_lt()
2146        {
2147            self.range.start.clone()
2148        } else if text_anchor
2149            .cmp(&self.range.end, &self.buffer)
2150            .unwrap()
2151            .is_gt()
2152        {
2153            self.range.end.clone()
2154        } else {
2155            text_anchor
2156        }
2157    }
2158
2159    fn contains(&self, anchor: &Anchor) -> bool {
2160        self.buffer_id == anchor.buffer_id
2161            && self
2162                .range
2163                .start
2164                .cmp(&anchor.text_anchor, &self.buffer)
2165                .unwrap()
2166                .is_le()
2167            && self
2168                .range
2169                .end
2170                .cmp(&anchor.text_anchor, &self.buffer)
2171                .unwrap()
2172                .is_ge()
2173    }
2174}
2175
2176impl fmt::Debug for Excerpt {
2177    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
2178        f.debug_struct("Excerpt")
2179            .field("id", &self.id)
2180            .field("buffer_id", &self.buffer_id)
2181            .field("range", &self.range)
2182            .field("text_summary", &self.text_summary)
2183            .field("has_trailing_newline", &self.has_trailing_newline)
2184            .finish()
2185    }
2186}
2187
2188impl sum_tree::Item for Excerpt {
2189    type Summary = ExcerptSummary;
2190
2191    fn summary(&self) -> Self::Summary {
2192        let mut text = self.text_summary.clone();
2193        if self.has_trailing_newline {
2194            text += TextSummary::from("\n");
2195        }
2196        ExcerptSummary {
2197            excerpt_id: self.id.clone(),
2198            max_buffer_row: self.max_buffer_row,
2199            text,
2200        }
2201    }
2202}
2203
2204impl sum_tree::Summary for ExcerptSummary {
2205    type Context = ();
2206
2207    fn add_summary(&mut self, summary: &Self, _: &()) {
2208        debug_assert!(summary.excerpt_id > self.excerpt_id);
2209        self.excerpt_id = summary.excerpt_id.clone();
2210        self.text.add_summary(&summary.text, &());
2211        self.max_buffer_row = cmp::max(self.max_buffer_row, summary.max_buffer_row);
2212    }
2213}
2214
2215impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for TextSummary {
2216    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: &()) {
2217        *self += &summary.text;
2218    }
2219}
2220
2221impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for usize {
2222    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: &()) {
2223        *self += summary.text.bytes;
2224    }
2225}
2226
2227impl<'a> sum_tree::SeekTarget<'a, ExcerptSummary, ExcerptSummary> for usize {
2228    fn cmp(&self, cursor_location: &ExcerptSummary, _: &()) -> cmp::Ordering {
2229        Ord::cmp(self, &cursor_location.text.bytes)
2230    }
2231}
2232
2233impl<'a> sum_tree::SeekTarget<'a, ExcerptSummary, ExcerptSummary> for Option<&'a ExcerptId> {
2234    fn cmp(&self, cursor_location: &ExcerptSummary, _: &()) -> cmp::Ordering {
2235        Ord::cmp(self, &Some(&cursor_location.excerpt_id))
2236    }
2237}
2238
2239impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for Point {
2240    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: &()) {
2241        *self += summary.text.lines;
2242    }
2243}
2244
2245impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for PointUtf16 {
2246    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: &()) {
2247        *self += summary.text.lines_utf16
2248    }
2249}
2250
2251impl<'a> sum_tree::Dimension<'a, ExcerptSummary> for Option<&'a ExcerptId> {
2252    fn add_summary(&mut self, summary: &'a ExcerptSummary, _: &()) {
2253        *self = Some(&summary.excerpt_id);
2254    }
2255}
2256
2257impl<'a> MultiBufferRows<'a> {
2258    pub fn seek(&mut self, row: u32) {
2259        self.buffer_row_range = 0..0;
2260
2261        self.excerpts
2262            .seek_forward(&Point::new(row, 0), Bias::Right, &());
2263        if self.excerpts.item().is_none() {
2264            self.excerpts.prev(&());
2265
2266            if self.excerpts.item().is_none() && row == 0 {
2267                self.buffer_row_range = 0..1;
2268                return;
2269            }
2270        }
2271
2272        if let Some(excerpt) = self.excerpts.item() {
2273            let overshoot = row - self.excerpts.start().row;
2274            let excerpt_start = excerpt.range.start.to_point(&excerpt.buffer).row;
2275            self.buffer_row_range.start = excerpt_start + overshoot;
2276            self.buffer_row_range.end = excerpt_start + excerpt.text_summary.lines.row + 1;
2277        }
2278    }
2279}
2280
2281impl<'a> Iterator for MultiBufferRows<'a> {
2282    type Item = Option<u32>;
2283
2284    fn next(&mut self) -> Option<Self::Item> {
2285        loop {
2286            if !self.buffer_row_range.is_empty() {
2287                let row = Some(self.buffer_row_range.start);
2288                self.buffer_row_range.start += 1;
2289                return Some(row);
2290            }
2291            self.excerpts.item()?;
2292            self.excerpts.next(&());
2293            let excerpt = self.excerpts.item()?;
2294            self.buffer_row_range.start = excerpt.range.start.to_point(&excerpt.buffer).row;
2295            self.buffer_row_range.end =
2296                self.buffer_row_range.start + excerpt.text_summary.lines.row + 1;
2297        }
2298    }
2299}
2300
2301impl<'a> MultiBufferChunks<'a> {
2302    pub fn offset(&self) -> usize {
2303        self.range.start
2304    }
2305
2306    pub fn seek(&mut self, offset: usize) {
2307        self.range.start = offset;
2308        self.excerpts.seek(&offset, Bias::Right, &());
2309        if let Some(excerpt) = self.excerpts.item() {
2310            self.excerpt_chunks = Some(excerpt.chunks_in_range(
2311                self.range.start - self.excerpts.start()..self.range.end - self.excerpts.start(),
2312                self.theme,
2313            ));
2314        } else {
2315            self.excerpt_chunks = None;
2316        }
2317    }
2318}
2319
2320impl<'a> Iterator for MultiBufferChunks<'a> {
2321    type Item = Chunk<'a>;
2322
2323    fn next(&mut self) -> Option<Self::Item> {
2324        if self.range.is_empty() {
2325            None
2326        } else if let Some(chunk) = self.excerpt_chunks.as_mut()?.next() {
2327            self.range.start += chunk.text.len();
2328            Some(chunk)
2329        } else {
2330            self.excerpts.next(&());
2331            let excerpt = self.excerpts.item()?;
2332            self.excerpt_chunks = Some(
2333                excerpt.chunks_in_range(0..self.range.end - self.excerpts.start(), self.theme),
2334            );
2335            self.next()
2336        }
2337    }
2338}
2339
2340impl<'a> MultiBufferBytes<'a> {
2341    fn consume(&mut self, len: usize) {
2342        self.range.start += len;
2343        self.chunk = &self.chunk[len..];
2344
2345        if !self.range.is_empty() && self.chunk.is_empty() {
2346            if let Some(chunk) = self.excerpt_bytes.as_mut().and_then(|bytes| bytes.next()) {
2347                self.chunk = chunk;
2348            } else {
2349                self.excerpts.next(&());
2350                if let Some(excerpt) = self.excerpts.item() {
2351                    let mut excerpt_bytes =
2352                        excerpt.bytes_in_range(0..self.range.end - self.excerpts.start());
2353                    self.chunk = excerpt_bytes.next().unwrap();
2354                    self.excerpt_bytes = Some(excerpt_bytes);
2355                }
2356            }
2357        }
2358    }
2359}
2360
2361impl<'a> Iterator for MultiBufferBytes<'a> {
2362    type Item = &'a [u8];
2363
2364    fn next(&mut self) -> Option<Self::Item> {
2365        let chunk = self.chunk;
2366        if chunk.is_empty() {
2367            None
2368        } else {
2369            self.consume(chunk.len());
2370            Some(chunk)
2371        }
2372    }
2373}
2374
2375impl<'a> io::Read for MultiBufferBytes<'a> {
2376    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
2377        let len = cmp::min(buf.len(), self.chunk.len());
2378        buf[..len].copy_from_slice(&self.chunk[..len]);
2379        if len > 0 {
2380            self.consume(len);
2381        }
2382        Ok(len)
2383    }
2384}
2385
2386impl<'a> Iterator for ExcerptBytes<'a> {
2387    type Item = &'a [u8];
2388
2389    fn next(&mut self) -> Option<Self::Item> {
2390        if let Some(chunk) = self.content_bytes.next() {
2391            if !chunk.is_empty() {
2392                return Some(chunk);
2393            }
2394        }
2395
2396        if self.footer_height > 0 {
2397            let result = &NEWLINES[..self.footer_height];
2398            self.footer_height = 0;
2399            return Some(result);
2400        }
2401
2402        None
2403    }
2404}
2405
2406impl<'a> Iterator for ExcerptChunks<'a> {
2407    type Item = Chunk<'a>;
2408
2409    fn next(&mut self) -> Option<Self::Item> {
2410        if let Some(chunk) = self.content_chunks.next() {
2411            return Some(chunk);
2412        }
2413
2414        if self.footer_height > 0 {
2415            let text = unsafe { str::from_utf8_unchecked(&NEWLINES[..self.footer_height]) };
2416            self.footer_height = 0;
2417            return Some(Chunk {
2418                text,
2419                ..Default::default()
2420            });
2421        }
2422
2423        None
2424    }
2425}
2426
2427impl ToOffset for Point {
2428    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
2429        snapshot.point_to_offset(*self)
2430    }
2431}
2432
2433impl ToOffset for PointUtf16 {
2434    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
2435        snapshot.point_utf16_to_offset(*self)
2436    }
2437}
2438
2439impl ToOffset for usize {
2440    fn to_offset<'a>(&self, snapshot: &MultiBufferSnapshot) -> usize {
2441        assert!(*self <= snapshot.len(), "offset is out of range");
2442        *self
2443    }
2444}
2445
2446impl ToPoint for usize {
2447    fn to_point<'a>(&self, snapshot: &MultiBufferSnapshot) -> Point {
2448        snapshot.offset_to_point(*self)
2449    }
2450}
2451
2452impl ToPoint for Point {
2453    fn to_point<'a>(&self, _: &MultiBufferSnapshot) -> Point {
2454        *self
2455    }
2456}
2457
2458pub fn char_kind(c: char) -> CharKind {
2459    if c == '\n' {
2460        CharKind::Newline
2461    } else if c.is_whitespace() {
2462        CharKind::Whitespace
2463    } else if c.is_alphanumeric() || c == '_' {
2464        CharKind::Word
2465    } else {
2466        CharKind::Punctuation
2467    }
2468}
2469
2470#[cfg(test)]
2471mod tests {
2472    use super::*;
2473    use gpui::MutableAppContext;
2474    use language::{Buffer, Rope};
2475    use rand::prelude::*;
2476    use std::env;
2477    use text::{Point, RandomCharIter};
2478    use util::test::sample_text;
2479
2480    #[gpui::test]
2481    fn test_singleton_multibuffer(cx: &mut MutableAppContext) {
2482        let buffer = cx.add_model(|cx| Buffer::new(0, sample_text(6, 6, 'a'), cx));
2483        let multibuffer = cx.add_model(|cx| MultiBuffer::singleton(buffer.clone(), cx));
2484
2485        let snapshot = multibuffer.read(cx).snapshot(cx);
2486        assert_eq!(snapshot.text(), buffer.read(cx).text());
2487
2488        assert_eq!(
2489            snapshot.buffer_rows(0).collect::<Vec<_>>(),
2490            (0..buffer.read(cx).row_count())
2491                .map(Some)
2492                .collect::<Vec<_>>()
2493        );
2494
2495        buffer.update(cx, |buffer, cx| buffer.edit([1..3], "XXX\n", cx));
2496        let snapshot = multibuffer.read(cx).snapshot(cx);
2497
2498        assert_eq!(snapshot.text(), buffer.read(cx).text());
2499        assert_eq!(
2500            snapshot.buffer_rows(0).collect::<Vec<_>>(),
2501            (0..buffer.read(cx).row_count())
2502                .map(Some)
2503                .collect::<Vec<_>>()
2504        );
2505    }
2506
2507    #[gpui::test]
2508    fn test_remote_multibuffer(cx: &mut MutableAppContext) {
2509        let host_buffer = cx.add_model(|cx| Buffer::new(0, "a", cx));
2510        let guest_buffer = cx.add_model(|cx| {
2511            let message = host_buffer.read(cx).to_proto();
2512            Buffer::from_proto(1, message, None, cx).unwrap()
2513        });
2514        let multibuffer = cx.add_model(|cx| MultiBuffer::singleton(guest_buffer.clone(), cx));
2515        let snapshot = multibuffer.read(cx).snapshot(cx);
2516        assert_eq!(snapshot.text(), "a");
2517
2518        guest_buffer.update(cx, |buffer, cx| buffer.edit([1..1], "b", cx));
2519        let snapshot = multibuffer.read(cx).snapshot(cx);
2520        assert_eq!(snapshot.text(), "ab");
2521
2522        guest_buffer.update(cx, |buffer, cx| buffer.edit([2..2], "c", cx));
2523        let snapshot = multibuffer.read(cx).snapshot(cx);
2524        assert_eq!(snapshot.text(), "abc");
2525    }
2526
2527    #[gpui::test]
2528    fn test_excerpt_buffer(cx: &mut MutableAppContext) {
2529        let buffer_1 = cx.add_model(|cx| Buffer::new(0, sample_text(6, 6, 'a'), cx));
2530        let buffer_2 = cx.add_model(|cx| Buffer::new(0, sample_text(6, 6, 'g'), cx));
2531        let multibuffer = cx.add_model(|_| MultiBuffer::new(0));
2532
2533        let subscription = multibuffer.update(cx, |multibuffer, cx| {
2534            let subscription = multibuffer.subscribe();
2535            multibuffer.push_excerpt(
2536                ExcerptProperties {
2537                    buffer: &buffer_1,
2538                    range: Point::new(1, 2)..Point::new(2, 5),
2539                },
2540                cx,
2541            );
2542            assert_eq!(
2543                subscription.consume().into_inner(),
2544                [Edit {
2545                    old: 0..0,
2546                    new: 0..10
2547                }]
2548            );
2549
2550            multibuffer.push_excerpt(
2551                ExcerptProperties {
2552                    buffer: &buffer_1,
2553                    range: Point::new(3, 3)..Point::new(4, 4),
2554                },
2555                cx,
2556            );
2557            multibuffer.push_excerpt(
2558                ExcerptProperties {
2559                    buffer: &buffer_2,
2560                    range: Point::new(3, 1)..Point::new(3, 3),
2561                },
2562                cx,
2563            );
2564            assert_eq!(
2565                subscription.consume().into_inner(),
2566                [Edit {
2567                    old: 10..10,
2568                    new: 10..22
2569                }]
2570            );
2571
2572            subscription
2573        });
2574
2575        let snapshot = multibuffer.read(cx).snapshot(cx);
2576        assert_eq!(
2577            snapshot.text(),
2578            concat!(
2579                "bbbb\n",  // Preserve newlines
2580                "ccccc\n", //
2581                "ddd\n",   //
2582                "eeee\n",  //
2583                "jj"       //
2584            )
2585        );
2586        assert_eq!(
2587            snapshot.buffer_rows(0).collect::<Vec<_>>(),
2588            [Some(1), Some(2), Some(3), Some(4), Some(3)]
2589        );
2590        assert_eq!(
2591            snapshot.buffer_rows(2).collect::<Vec<_>>(),
2592            [Some(3), Some(4), Some(3)]
2593        );
2594        assert_eq!(snapshot.buffer_rows(4).collect::<Vec<_>>(), [Some(3)]);
2595        assert_eq!(snapshot.buffer_rows(5).collect::<Vec<_>>(), []);
2596        assert!(!snapshot.range_contains_excerpt_boundary(Point::new(1, 0)..Point::new(1, 5)));
2597        assert!(snapshot.range_contains_excerpt_boundary(Point::new(1, 0)..Point::new(2, 0)));
2598        assert!(snapshot.range_contains_excerpt_boundary(Point::new(1, 0)..Point::new(4, 0)));
2599        assert!(!snapshot.range_contains_excerpt_boundary(Point::new(2, 0)..Point::new(3, 0)));
2600        assert!(!snapshot.range_contains_excerpt_boundary(Point::new(4, 0)..Point::new(4, 2)));
2601        assert!(!snapshot.range_contains_excerpt_boundary(Point::new(4, 2)..Point::new(4, 2)));
2602
2603        buffer_1.update(cx, |buffer, cx| {
2604            buffer.edit(
2605                [
2606                    Point::new(0, 0)..Point::new(0, 0),
2607                    Point::new(2, 1)..Point::new(2, 3),
2608                ],
2609                "\n",
2610                cx,
2611            );
2612        });
2613
2614        let snapshot = multibuffer.read(cx).snapshot(cx);
2615        assert_eq!(
2616            snapshot.text(),
2617            concat!(
2618                "bbbb\n", // Preserve newlines
2619                "c\n",    //
2620                "cc\n",   //
2621                "ddd\n",  //
2622                "eeee\n", //
2623                "jj"      //
2624            )
2625        );
2626
2627        assert_eq!(
2628            subscription.consume().into_inner(),
2629            [Edit {
2630                old: 6..8,
2631                new: 6..7
2632            }]
2633        );
2634
2635        let snapshot = multibuffer.read(cx).snapshot(cx);
2636        assert_eq!(
2637            snapshot.clip_point(Point::new(0, 5), Bias::Left),
2638            Point::new(0, 4)
2639        );
2640        assert_eq!(
2641            snapshot.clip_point(Point::new(0, 5), Bias::Right),
2642            Point::new(0, 4)
2643        );
2644        assert_eq!(
2645            snapshot.clip_point(Point::new(5, 1), Bias::Right),
2646            Point::new(5, 1)
2647        );
2648        assert_eq!(
2649            snapshot.clip_point(Point::new(5, 2), Bias::Right),
2650            Point::new(5, 2)
2651        );
2652        assert_eq!(
2653            snapshot.clip_point(Point::new(5, 3), Bias::Right),
2654            Point::new(5, 2)
2655        );
2656
2657        let snapshot = multibuffer.update(cx, |multibuffer, cx| {
2658            let buffer_2_excerpt_id = multibuffer.excerpt_ids_for_buffer(&buffer_2)[0].clone();
2659            multibuffer.remove_excerpts(&[buffer_2_excerpt_id], cx);
2660            multibuffer.snapshot(cx)
2661        });
2662
2663        assert_eq!(
2664            snapshot.text(),
2665            concat!(
2666                "bbbb\n", // Preserve newlines
2667                "c\n",    //
2668                "cc\n",   //
2669                "ddd\n",  //
2670                "eeee",   //
2671            )
2672        );
2673    }
2674
2675    #[gpui::test]
2676    fn test_empty_excerpt_buffer(cx: &mut MutableAppContext) {
2677        let multibuffer = cx.add_model(|_| MultiBuffer::new(0));
2678
2679        let snapshot = multibuffer.read(cx).snapshot(cx);
2680        assert_eq!(snapshot.text(), "");
2681        assert_eq!(snapshot.buffer_rows(0).collect::<Vec<_>>(), &[Some(0)]);
2682        assert_eq!(snapshot.buffer_rows(1).collect::<Vec<_>>(), &[]);
2683    }
2684
2685    #[gpui::test]
2686    fn test_singleton_multibuffer_anchors(cx: &mut MutableAppContext) {
2687        let buffer = cx.add_model(|cx| Buffer::new(0, "abcd", cx));
2688        let multibuffer = cx.add_model(|cx| MultiBuffer::singleton(buffer.clone(), cx));
2689        let old_snapshot = multibuffer.read(cx).snapshot(cx);
2690        buffer.update(cx, |buffer, cx| {
2691            buffer.edit([0..0], "X", cx);
2692            buffer.edit([5..5], "Y", cx);
2693        });
2694        let new_snapshot = multibuffer.read(cx).snapshot(cx);
2695
2696        assert_eq!(old_snapshot.text(), "abcd");
2697        assert_eq!(new_snapshot.text(), "XabcdY");
2698
2699        assert_eq!(old_snapshot.anchor_before(0).to_offset(&new_snapshot), 0);
2700        assert_eq!(old_snapshot.anchor_after(0).to_offset(&new_snapshot), 1);
2701        assert_eq!(old_snapshot.anchor_before(4).to_offset(&new_snapshot), 5);
2702        assert_eq!(old_snapshot.anchor_after(4).to_offset(&new_snapshot), 6);
2703    }
2704
2705    #[gpui::test]
2706    fn test_multibuffer_anchors(cx: &mut MutableAppContext) {
2707        let buffer_1 = cx.add_model(|cx| Buffer::new(0, "abcd", cx));
2708        let buffer_2 = cx.add_model(|cx| Buffer::new(0, "efghi", cx));
2709        let multibuffer = cx.add_model(|cx| {
2710            let mut multibuffer = MultiBuffer::new(0);
2711            multibuffer.push_excerpt(
2712                ExcerptProperties {
2713                    buffer: &buffer_1,
2714                    range: 0..4,
2715                },
2716                cx,
2717            );
2718            multibuffer.push_excerpt(
2719                ExcerptProperties {
2720                    buffer: &buffer_2,
2721                    range: 0..5,
2722                },
2723                cx,
2724            );
2725            multibuffer
2726        });
2727        let old_snapshot = multibuffer.read(cx).snapshot(cx);
2728
2729        assert_eq!(old_snapshot.anchor_before(0).to_offset(&old_snapshot), 0);
2730        assert_eq!(old_snapshot.anchor_after(0).to_offset(&old_snapshot), 0);
2731        assert_eq!(Anchor::min().to_offset(&old_snapshot), 0);
2732        assert_eq!(Anchor::min().to_offset(&old_snapshot), 0);
2733        assert_eq!(Anchor::max().to_offset(&old_snapshot), 10);
2734        assert_eq!(Anchor::max().to_offset(&old_snapshot), 10);
2735
2736        buffer_1.update(cx, |buffer, cx| {
2737            buffer.edit([0..0], "W", cx);
2738            buffer.edit([5..5], "X", cx);
2739        });
2740        buffer_2.update(cx, |buffer, cx| {
2741            buffer.edit([0..0], "Y", cx);
2742            buffer.edit([6..0], "Z", cx);
2743        });
2744        let new_snapshot = multibuffer.read(cx).snapshot(cx);
2745
2746        assert_eq!(old_snapshot.text(), "abcd\nefghi");
2747        assert_eq!(new_snapshot.text(), "WabcdX\nYefghiZ");
2748
2749        assert_eq!(old_snapshot.anchor_before(0).to_offset(&new_snapshot), 0);
2750        assert_eq!(old_snapshot.anchor_after(0).to_offset(&new_snapshot), 1);
2751        assert_eq!(old_snapshot.anchor_before(1).to_offset(&new_snapshot), 2);
2752        assert_eq!(old_snapshot.anchor_after(1).to_offset(&new_snapshot), 2);
2753        assert_eq!(old_snapshot.anchor_before(2).to_offset(&new_snapshot), 3);
2754        assert_eq!(old_snapshot.anchor_after(2).to_offset(&new_snapshot), 3);
2755        assert_eq!(old_snapshot.anchor_before(5).to_offset(&new_snapshot), 7);
2756        assert_eq!(old_snapshot.anchor_after(5).to_offset(&new_snapshot), 8);
2757        assert_eq!(old_snapshot.anchor_before(10).to_offset(&new_snapshot), 13);
2758        assert_eq!(old_snapshot.anchor_after(10).to_offset(&new_snapshot), 14);
2759    }
2760
2761    #[gpui::test]
2762    fn test_multibuffer_resolving_anchors_after_replacing_their_excerpts(
2763        cx: &mut MutableAppContext,
2764    ) {
2765        let buffer_1 = cx.add_model(|cx| Buffer::new(0, "abcd", cx));
2766        let buffer_2 = cx.add_model(|cx| Buffer::new(0, "ABCDEFGHIJKLMNOP", cx));
2767        let multibuffer = cx.add_model(|_| MultiBuffer::new(0));
2768
2769        // Create an insertion id in buffer 1 that doesn't exist in buffer 2.
2770        // Add an excerpt from buffer 1 that spans this new insertion.
2771        buffer_1.update(cx, |buffer, cx| buffer.edit([4..4], "123", cx));
2772        let excerpt_id_1 = multibuffer.update(cx, |multibuffer, cx| {
2773            multibuffer.push_excerpt(
2774                ExcerptProperties {
2775                    buffer: &buffer_1,
2776                    range: 0..7,
2777                },
2778                cx,
2779            )
2780        });
2781
2782        let snapshot_1 = multibuffer.read(cx).snapshot(cx);
2783        assert_eq!(snapshot_1.text(), "abcd123");
2784
2785        // Replace the buffer 1 excerpt with new excerpts from buffer 2.
2786        let (excerpt_id_2, excerpt_id_3, _) = multibuffer.update(cx, |multibuffer, cx| {
2787            multibuffer.remove_excerpts([&excerpt_id_1], cx);
2788            (
2789                multibuffer.push_excerpt(
2790                    ExcerptProperties {
2791                        buffer: &buffer_2,
2792                        range: 0..4,
2793                    },
2794                    cx,
2795                ),
2796                multibuffer.push_excerpt(
2797                    ExcerptProperties {
2798                        buffer: &buffer_2,
2799                        range: 6..10,
2800                    },
2801                    cx,
2802                ),
2803                multibuffer.push_excerpt(
2804                    ExcerptProperties {
2805                        buffer: &buffer_2,
2806                        range: 12..16,
2807                    },
2808                    cx,
2809                ),
2810            )
2811        });
2812        let snapshot_2 = multibuffer.read(cx).snapshot(cx);
2813        assert_eq!(snapshot_2.text(), "ABCD\nGHIJ\nMNOP");
2814
2815        // The old excerpt id has been reused.
2816        assert_eq!(excerpt_id_2, excerpt_id_1);
2817
2818        // Resolve some anchors from the previous snapshot in the new snapshot.
2819        // Although there is still an excerpt with the same id, it is for
2820        // a different buffer, so we don't attempt to resolve the old text
2821        // anchor in the new buffer.
2822        assert_eq!(
2823            snapshot_2.summary_for_anchor::<usize>(&snapshot_1.anchor_before(2)),
2824            0
2825        );
2826        assert_eq!(
2827            snapshot_2.summaries_for_anchors::<usize, _>(&[
2828                snapshot_1.anchor_before(2),
2829                snapshot_1.anchor_after(3)
2830            ]),
2831            vec![0, 0]
2832        );
2833        let refresh =
2834            snapshot_2.refresh_anchors(&[snapshot_1.anchor_before(2), snapshot_1.anchor_after(3)]);
2835        assert_eq!(
2836            refresh,
2837            &[
2838                (0, snapshot_2.anchor_before(0), false),
2839                (1, snapshot_2.anchor_after(0), false),
2840            ]
2841        );
2842
2843        // Replace the middle excerpt with a smaller excerpt in buffer 2,
2844        // that intersects the old excerpt.
2845        let excerpt_id_5 = multibuffer.update(cx, |multibuffer, cx| {
2846            multibuffer.remove_excerpts([&excerpt_id_3], cx);
2847            multibuffer.insert_excerpt_after(
2848                &excerpt_id_3,
2849                ExcerptProperties {
2850                    buffer: &buffer_2,
2851                    range: 5..8,
2852                },
2853                cx,
2854            )
2855        });
2856
2857        let snapshot_3 = multibuffer.read(cx).snapshot(cx);
2858        assert_eq!(snapshot_3.text(), "ABCD\nFGH\nMNOP");
2859        assert_ne!(excerpt_id_5, excerpt_id_3);
2860
2861        // Resolve some anchors from the previous snapshot in the new snapshot.
2862        // The anchor in the middle excerpt snaps to the beginning of the
2863        // excerpt, since it is not
2864        let anchors = [
2865            snapshot_2.anchor_before(0),
2866            snapshot_2.anchor_after(2),
2867            snapshot_2.anchor_after(6),
2868            snapshot_2.anchor_after(14),
2869        ];
2870        assert_eq!(
2871            snapshot_3.summaries_for_anchors::<usize, _>(&anchors),
2872            &[0, 2, 9, 13]
2873        );
2874
2875        let new_anchors = snapshot_3.refresh_anchors(&anchors);
2876        assert_eq!(
2877            new_anchors.iter().map(|a| (a.0, a.2)).collect::<Vec<_>>(),
2878            &[(0, true), (1, true), (2, true), (3, true)]
2879        );
2880        assert_eq!(
2881            snapshot_3.summaries_for_anchors::<usize, _>(new_anchors.iter().map(|a| &a.1)),
2882            &[0, 2, 7, 13]
2883        );
2884    }
2885
2886    #[gpui::test(iterations = 100)]
2887    fn test_random_multibuffer(cx: &mut MutableAppContext, mut rng: StdRng) {
2888        let operations = env::var("OPERATIONS")
2889            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
2890            .unwrap_or(10);
2891
2892        let mut buffers: Vec<ModelHandle<Buffer>> = Vec::new();
2893        let multibuffer = cx.add_model(|_| MultiBuffer::new(0));
2894        let mut excerpt_ids = Vec::new();
2895        let mut expected_excerpts = Vec::<(ModelHandle<Buffer>, Range<text::Anchor>)>::new();
2896        let mut anchors = Vec::new();
2897        let mut old_versions = Vec::new();
2898
2899        for _ in 0..operations {
2900            match rng.gen_range(0..100) {
2901                0..=19 if !buffers.is_empty() => {
2902                    let buffer = buffers.choose(&mut rng).unwrap();
2903                    buffer.update(cx, |buf, cx| buf.randomly_edit(&mut rng, 5, cx));
2904                }
2905                20..=29 if !expected_excerpts.is_empty() => {
2906                    let mut ids_to_remove = vec![];
2907                    for _ in 0..rng.gen_range(1..=3) {
2908                        if expected_excerpts.is_empty() {
2909                            break;
2910                        }
2911
2912                        let ix = rng.gen_range(0..expected_excerpts.len());
2913                        ids_to_remove.push(excerpt_ids.remove(ix));
2914                        let (buffer, range) = expected_excerpts.remove(ix);
2915                        let buffer = buffer.read(cx);
2916                        log::info!(
2917                            "Removing excerpt {}: {:?}",
2918                            ix,
2919                            buffer
2920                                .text_for_range(range.to_offset(&buffer))
2921                                .collect::<String>(),
2922                        );
2923                    }
2924                    ids_to_remove.sort_unstable();
2925                    multibuffer.update(cx, |multibuffer, cx| {
2926                        multibuffer.remove_excerpts(&ids_to_remove, cx)
2927                    });
2928                }
2929                30..=39 if !expected_excerpts.is_empty() => {
2930                    let multibuffer = multibuffer.read(cx).read(cx);
2931                    let offset =
2932                        multibuffer.clip_offset(rng.gen_range(0..=multibuffer.len()), Bias::Left);
2933                    let bias = if rng.gen() { Bias::Left } else { Bias::Right };
2934                    log::info!("Creating anchor at {} with bias {:?}", offset, bias);
2935                    anchors.push(multibuffer.anchor_at(offset, bias));
2936                    anchors.sort_by(|a, b| a.cmp(&b, &multibuffer).unwrap());
2937                }
2938                40..=44 if !anchors.is_empty() => {
2939                    let multibuffer = multibuffer.read(cx).read(cx);
2940
2941                    anchors = multibuffer
2942                        .refresh_anchors(&anchors)
2943                        .into_iter()
2944                        .map(|a| a.1)
2945                        .collect();
2946
2947                    // Ensure the newly-refreshed anchors point to a valid excerpt and don't
2948                    // overshoot its boundaries.
2949                    let mut cursor = multibuffer.excerpts.cursor::<Option<&ExcerptId>>();
2950                    for anchor in &anchors {
2951                        if anchor.excerpt_id == ExcerptId::min()
2952                            || anchor.excerpt_id == ExcerptId::max()
2953                        {
2954                            continue;
2955                        }
2956
2957                        cursor.seek_forward(&Some(&anchor.excerpt_id), Bias::Left, &());
2958                        let excerpt = cursor.item().unwrap();
2959                        assert_eq!(excerpt.id, anchor.excerpt_id);
2960                        assert!(excerpt.contains(anchor));
2961                    }
2962                }
2963                _ => {
2964                    let buffer_handle = if buffers.is_empty() || rng.gen_bool(0.4) {
2965                        let base_text = RandomCharIter::new(&mut rng).take(10).collect::<String>();
2966                        buffers.push(cx.add_model(|cx| Buffer::new(0, base_text, cx)));
2967                        buffers.last().unwrap()
2968                    } else {
2969                        buffers.choose(&mut rng).unwrap()
2970                    };
2971
2972                    let buffer = buffer_handle.read(cx);
2973                    let end_ix = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Right);
2974                    let start_ix = buffer.clip_offset(rng.gen_range(0..=end_ix), Bias::Left);
2975                    let anchor_range = buffer.anchor_before(start_ix)..buffer.anchor_after(end_ix);
2976                    let prev_excerpt_ix = rng.gen_range(0..=expected_excerpts.len());
2977                    let prev_excerpt_id = excerpt_ids
2978                        .get(prev_excerpt_ix)
2979                        .cloned()
2980                        .unwrap_or(ExcerptId::max());
2981                    let excerpt_ix = (prev_excerpt_ix + 1).min(expected_excerpts.len());
2982
2983                    log::info!(
2984                        "Inserting excerpt at {} of {} for buffer {}: {:?}[{:?}] = {:?}",
2985                        excerpt_ix,
2986                        expected_excerpts.len(),
2987                        buffer_handle.id(),
2988                        buffer.text(),
2989                        start_ix..end_ix,
2990                        &buffer.text()[start_ix..end_ix]
2991                    );
2992
2993                    let excerpt_id = multibuffer.update(cx, |multibuffer, cx| {
2994                        multibuffer.insert_excerpt_after(
2995                            &prev_excerpt_id,
2996                            ExcerptProperties {
2997                                buffer: &buffer_handle,
2998                                range: start_ix..end_ix,
2999                            },
3000                            cx,
3001                        )
3002                    });
3003
3004                    excerpt_ids.insert(excerpt_ix, excerpt_id);
3005                    expected_excerpts.insert(excerpt_ix, (buffer_handle.clone(), anchor_range));
3006                }
3007            }
3008
3009            if rng.gen_bool(0.3) {
3010                multibuffer.update(cx, |multibuffer, cx| {
3011                    old_versions.push((multibuffer.snapshot(cx), multibuffer.subscribe()));
3012                })
3013            }
3014
3015            let snapshot = multibuffer.read(cx).snapshot(cx);
3016
3017            let mut excerpt_starts = Vec::new();
3018            let mut expected_text = String::new();
3019            let mut expected_buffer_rows = Vec::new();
3020            for (buffer, range) in &expected_excerpts {
3021                let buffer = buffer.read(cx);
3022                let buffer_range = range.to_offset(buffer);
3023
3024                excerpt_starts.push(TextSummary::from(expected_text.as_str()));
3025                expected_text.extend(buffer.text_for_range(buffer_range.clone()));
3026                expected_text.push('\n');
3027
3028                let buffer_row_range = buffer.offset_to_point(buffer_range.start).row
3029                    ..=buffer.offset_to_point(buffer_range.end).row;
3030                for row in buffer_row_range {
3031                    expected_buffer_rows.push(Some(row));
3032                }
3033            }
3034            // Remove final trailing newline.
3035            if !expected_excerpts.is_empty() {
3036                expected_text.pop();
3037            }
3038
3039            // Always report one buffer row
3040            if expected_buffer_rows.is_empty() {
3041                expected_buffer_rows.push(Some(0));
3042            }
3043
3044            assert_eq!(snapshot.text(), expected_text);
3045            log::info!("MultiBuffer text: {:?}", expected_text);
3046
3047            assert_eq!(
3048                snapshot.buffer_rows(0).collect::<Vec<_>>(),
3049                expected_buffer_rows,
3050            );
3051
3052            for _ in 0..5 {
3053                let start_row = rng.gen_range(0..=expected_buffer_rows.len());
3054                assert_eq!(
3055                    snapshot.buffer_rows(start_row as u32).collect::<Vec<_>>(),
3056                    &expected_buffer_rows[start_row..],
3057                    "buffer_rows({})",
3058                    start_row
3059                );
3060            }
3061
3062            assert_eq!(
3063                snapshot.max_buffer_row(),
3064                expected_buffer_rows
3065                    .into_iter()
3066                    .filter_map(|r| r)
3067                    .max()
3068                    .unwrap()
3069            );
3070
3071            let mut excerpt_starts = excerpt_starts.into_iter();
3072            for (buffer, range) in &expected_excerpts {
3073                let buffer_id = buffer.id();
3074                let buffer = buffer.read(cx);
3075                let buffer_range = range.to_offset(buffer);
3076                let buffer_start_point = buffer.offset_to_point(buffer_range.start);
3077                let buffer_start_point_utf16 =
3078                    buffer.text_summary_for_range::<PointUtf16, _>(0..buffer_range.start);
3079
3080                let excerpt_start = excerpt_starts.next().unwrap();
3081                let mut offset = excerpt_start.bytes;
3082                let mut buffer_offset = buffer_range.start;
3083                let mut point = excerpt_start.lines;
3084                let mut buffer_point = buffer_start_point;
3085                let mut point_utf16 = excerpt_start.lines_utf16;
3086                let mut buffer_point_utf16 = buffer_start_point_utf16;
3087                for ch in buffer
3088                    .snapshot()
3089                    .chunks(buffer_range.clone(), None)
3090                    .flat_map(|c| c.text.chars())
3091                {
3092                    for _ in 0..ch.len_utf8() {
3093                        let left_offset = snapshot.clip_offset(offset, Bias::Left);
3094                        let right_offset = snapshot.clip_offset(offset, Bias::Right);
3095                        let buffer_left_offset = buffer.clip_offset(buffer_offset, Bias::Left);
3096                        let buffer_right_offset = buffer.clip_offset(buffer_offset, Bias::Right);
3097                        assert_eq!(
3098                            left_offset,
3099                            excerpt_start.bytes + (buffer_left_offset - buffer_range.start),
3100                            "clip_offset({:?}, Left). buffer: {:?}, buffer offset: {:?}",
3101                            offset,
3102                            buffer_id,
3103                            buffer_offset,
3104                        );
3105                        assert_eq!(
3106                            right_offset,
3107                            excerpt_start.bytes + (buffer_right_offset - buffer_range.start),
3108                            "clip_offset({:?}, Right). buffer: {:?}, buffer offset: {:?}",
3109                            offset,
3110                            buffer_id,
3111                            buffer_offset,
3112                        );
3113
3114                        let left_point = snapshot.clip_point(point, Bias::Left);
3115                        let right_point = snapshot.clip_point(point, Bias::Right);
3116                        let buffer_left_point = buffer.clip_point(buffer_point, Bias::Left);
3117                        let buffer_right_point = buffer.clip_point(buffer_point, Bias::Right);
3118                        assert_eq!(
3119                            left_point,
3120                            excerpt_start.lines + (buffer_left_point - buffer_start_point),
3121                            "clip_point({:?}, Left). buffer: {:?}, buffer point: {:?}",
3122                            point,
3123                            buffer_id,
3124                            buffer_point,
3125                        );
3126                        assert_eq!(
3127                            right_point,
3128                            excerpt_start.lines + (buffer_right_point - buffer_start_point),
3129                            "clip_point({:?}, Right). buffer: {:?}, buffer point: {:?}",
3130                            point,
3131                            buffer_id,
3132                            buffer_point,
3133                        );
3134
3135                        assert_eq!(
3136                            snapshot.point_to_offset(left_point),
3137                            left_offset,
3138                            "point_to_offset({:?})",
3139                            left_point,
3140                        );
3141                        assert_eq!(
3142                            snapshot.offset_to_point(left_offset),
3143                            left_point,
3144                            "offset_to_point({:?})",
3145                            left_offset,
3146                        );
3147
3148                        offset += 1;
3149                        buffer_offset += 1;
3150                        if ch == '\n' {
3151                            point += Point::new(1, 0);
3152                            buffer_point += Point::new(1, 0);
3153                        } else {
3154                            point += Point::new(0, 1);
3155                            buffer_point += Point::new(0, 1);
3156                        }
3157                    }
3158
3159                    for _ in 0..ch.len_utf16() {
3160                        let left_point_utf16 = snapshot.clip_point_utf16(point_utf16, Bias::Left);
3161                        let right_point_utf16 = snapshot.clip_point_utf16(point_utf16, Bias::Right);
3162                        let buffer_left_point_utf16 =
3163                            buffer.clip_point_utf16(buffer_point_utf16, Bias::Left);
3164                        let buffer_right_point_utf16 =
3165                            buffer.clip_point_utf16(buffer_point_utf16, Bias::Right);
3166                        assert_eq!(
3167                            left_point_utf16,
3168                            excerpt_start.lines_utf16
3169                                + (buffer_left_point_utf16 - buffer_start_point_utf16),
3170                            "clip_point_utf16({:?}, Left). buffer: {:?}, buffer point_utf16: {:?}",
3171                            point_utf16,
3172                            buffer_id,
3173                            buffer_point_utf16,
3174                        );
3175                        assert_eq!(
3176                            right_point_utf16,
3177                            excerpt_start.lines_utf16
3178                                + (buffer_right_point_utf16 - buffer_start_point_utf16),
3179                            "clip_point_utf16({:?}, Right). buffer: {:?}, buffer point_utf16: {:?}",
3180                            point_utf16,
3181                            buffer_id,
3182                            buffer_point_utf16,
3183                        );
3184
3185                        if ch == '\n' {
3186                            point_utf16 += PointUtf16::new(1, 0);
3187                            buffer_point_utf16 += PointUtf16::new(1, 0);
3188                        } else {
3189                            point_utf16 += PointUtf16::new(0, 1);
3190                            buffer_point_utf16 += PointUtf16::new(0, 1);
3191                        }
3192                    }
3193                }
3194            }
3195
3196            for (row, line) in expected_text.split('\n').enumerate() {
3197                assert_eq!(
3198                    snapshot.line_len(row as u32),
3199                    line.len() as u32,
3200                    "line_len({}).",
3201                    row
3202                );
3203            }
3204
3205            let text_rope = Rope::from(expected_text.as_str());
3206            for _ in 0..10 {
3207                let end_ix = text_rope.clip_offset(rng.gen_range(0..=text_rope.len()), Bias::Right);
3208                let start_ix = text_rope.clip_offset(rng.gen_range(0..=end_ix), Bias::Left);
3209
3210                let text_for_range = snapshot
3211                    .text_for_range(start_ix..end_ix)
3212                    .collect::<String>();
3213                assert_eq!(
3214                    text_for_range,
3215                    &expected_text[start_ix..end_ix],
3216                    "incorrect text for range {:?}",
3217                    start_ix..end_ix
3218                );
3219
3220                let excerpted_buffer_ranges =
3221                    multibuffer.read(cx).excerpted_buffers(start_ix..end_ix, cx);
3222                let excerpted_buffers_text = excerpted_buffer_ranges
3223                    .into_iter()
3224                    .map(|(buffer, buffer_range)| {
3225                        buffer
3226                            .read(cx)
3227                            .text_for_range(buffer_range)
3228                            .collect::<String>()
3229                    })
3230                    .collect::<Vec<_>>()
3231                    .join("\n");
3232                assert_eq!(excerpted_buffers_text, text_for_range);
3233
3234                let expected_summary = TextSummary::from(&expected_text[start_ix..end_ix]);
3235                assert_eq!(
3236                    snapshot.text_summary_for_range::<TextSummary, _>(start_ix..end_ix),
3237                    expected_summary,
3238                    "incorrect summary for range {:?}",
3239                    start_ix..end_ix
3240                );
3241            }
3242
3243            // Anchor resolution
3244            for (anchor, resolved_offset) in anchors
3245                .iter()
3246                .zip(snapshot.summaries_for_anchors::<usize, _>(&anchors))
3247            {
3248                assert!(resolved_offset <= snapshot.len());
3249                assert_eq!(
3250                    snapshot.summary_for_anchor::<usize>(anchor),
3251                    resolved_offset
3252                );
3253            }
3254
3255            for _ in 0..10 {
3256                let end_ix = text_rope.clip_offset(rng.gen_range(0..=text_rope.len()), Bias::Right);
3257                assert_eq!(
3258                    snapshot.reversed_chars_at(end_ix).collect::<String>(),
3259                    expected_text[..end_ix].chars().rev().collect::<String>(),
3260                );
3261            }
3262
3263            for _ in 0..10 {
3264                let end_ix = rng.gen_range(0..=text_rope.len());
3265                let start_ix = rng.gen_range(0..=end_ix);
3266                assert_eq!(
3267                    snapshot
3268                        .bytes_in_range(start_ix..end_ix)
3269                        .flatten()
3270                        .copied()
3271                        .collect::<Vec<_>>(),
3272                    expected_text.as_bytes()[start_ix..end_ix].to_vec(),
3273                    "bytes_in_range({:?})",
3274                    start_ix..end_ix,
3275                );
3276            }
3277        }
3278
3279        let snapshot = multibuffer.read(cx).snapshot(cx);
3280        for (old_snapshot, subscription) in old_versions {
3281            let edits = subscription.consume().into_inner();
3282
3283            log::info!(
3284                "applying subscription edits to old text: {:?}: {:?}",
3285                old_snapshot.text(),
3286                edits,
3287            );
3288
3289            let mut text = old_snapshot.text();
3290            for edit in edits {
3291                let new_text: String = snapshot.text_for_range(edit.new.clone()).collect();
3292                text.replace_range(edit.new.start..edit.new.start + edit.old.len(), &new_text);
3293            }
3294            assert_eq!(text.to_string(), snapshot.text());
3295        }
3296    }
3297
3298    #[gpui::test]
3299    fn test_history(cx: &mut MutableAppContext) {
3300        let buffer_1 = cx.add_model(|cx| Buffer::new(0, "1234", cx));
3301        let buffer_2 = cx.add_model(|cx| Buffer::new(0, "5678", cx));
3302        let multibuffer = cx.add_model(|_| MultiBuffer::new(0));
3303        let group_interval = multibuffer.read(cx).history.group_interval;
3304        multibuffer.update(cx, |multibuffer, cx| {
3305            multibuffer.push_excerpt(
3306                ExcerptProperties {
3307                    buffer: &buffer_1,
3308                    range: 0..buffer_1.read(cx).len(),
3309                },
3310                cx,
3311            );
3312            multibuffer.push_excerpt(
3313                ExcerptProperties {
3314                    buffer: &buffer_2,
3315                    range: 0..buffer_2.read(cx).len(),
3316                },
3317                cx,
3318            );
3319        });
3320
3321        let mut now = Instant::now();
3322
3323        multibuffer.update(cx, |multibuffer, cx| {
3324            multibuffer.start_transaction_at(now, cx);
3325            multibuffer.edit(
3326                [
3327                    Point::new(0, 0)..Point::new(0, 0),
3328                    Point::new(1, 0)..Point::new(1, 0),
3329                ],
3330                "A",
3331                cx,
3332            );
3333            multibuffer.edit(
3334                [
3335                    Point::new(0, 1)..Point::new(0, 1),
3336                    Point::new(1, 1)..Point::new(1, 1),
3337                ],
3338                "B",
3339                cx,
3340            );
3341            multibuffer.end_transaction_at(now, cx);
3342            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3343
3344            now += 2 * group_interval;
3345            multibuffer.start_transaction_at(now, cx);
3346            multibuffer.edit([2..2], "C", cx);
3347            multibuffer.end_transaction_at(now, cx);
3348            assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3349
3350            multibuffer.undo(cx);
3351            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3352
3353            multibuffer.undo(cx);
3354            assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3355
3356            multibuffer.redo(cx);
3357            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3358
3359            multibuffer.redo(cx);
3360            assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3361
3362            buffer_1.update(cx, |buffer_1, cx| buffer_1.undo(cx));
3363            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3364
3365            multibuffer.undo(cx);
3366            assert_eq!(multibuffer.read(cx).text(), "1234\n5678");
3367
3368            multibuffer.redo(cx);
3369            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3370
3371            multibuffer.redo(cx);
3372            assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3373
3374            multibuffer.undo(cx);
3375            assert_eq!(multibuffer.read(cx).text(), "AB1234\nAB5678");
3376
3377            buffer_1.update(cx, |buffer_1, cx| buffer_1.redo(cx));
3378            assert_eq!(multibuffer.read(cx).text(), "ABC1234\nAB5678");
3379
3380            multibuffer.undo(cx);
3381            assert_eq!(multibuffer.read(cx).text(), "C1234\n5678");
3382        });
3383    }
3384}