1use super::TextHighlights;
   2use crate::{
   3    multi_buffer::MultiBufferRows, Anchor, AnchorRangeExt, MultiBufferChunks, MultiBufferSnapshot,
   4    ToOffset,
   5};
   6use collections::BTreeMap;
   7use gpui::{color::Color, fonts::HighlightStyle};
   8use language::{Chunk, Edit, Point, TextSummary};
   9use parking_lot::Mutex;
  10use std::{
  11    any::TypeId,
  12    cmp::{self, Ordering},
  13    iter::{self, Peekable},
  14    ops::{Add, AddAssign, Range, Sub},
  15    sync::atomic::{AtomicUsize, Ordering::SeqCst},
  16    vec,
  17};
  18use sum_tree::{Bias, Cursor, FilterCursor, SumTree};
  19
  20#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  21pub struct FoldPoint(pub Point);
  22
  23impl FoldPoint {
  24    pub fn new(row: u32, column: u32) -> Self {
  25        Self(Point::new(row, column))
  26    }
  27
  28    pub fn row(self) -> u32 {
  29        self.0.row
  30    }
  31
  32    pub fn row_mut(&mut self) -> &mut u32 {
  33        &mut self.0.row
  34    }
  35
  36    pub fn column_mut(&mut self) -> &mut u32 {
  37        &mut self.0.column
  38    }
  39
  40    pub fn to_buffer_point(self, snapshot: &FoldSnapshot) -> Point {
  41        let mut cursor = snapshot.transforms.cursor::<(FoldPoint, Point)>();
  42        cursor.seek(&self, Bias::Right, &());
  43        let overshoot = self.0 - cursor.start().0 .0;
  44        cursor.start().1 + overshoot
  45    }
  46
  47    pub fn to_buffer_offset(self, snapshot: &FoldSnapshot) -> usize {
  48        let mut cursor = snapshot.transforms.cursor::<(FoldPoint, Point)>();
  49        cursor.seek(&self, Bias::Right, &());
  50        let overshoot = self.0 - cursor.start().0 .0;
  51        snapshot
  52            .buffer_snapshot
  53            .point_to_offset(cursor.start().1 + overshoot)
  54    }
  55
  56    pub fn to_offset(self, snapshot: &FoldSnapshot) -> FoldOffset {
  57        let mut cursor = snapshot
  58            .transforms
  59            .cursor::<(FoldPoint, TransformSummary)>();
  60        cursor.seek(&self, Bias::Right, &());
  61        let overshoot = self.0 - cursor.start().1.output.lines;
  62        let mut offset = cursor.start().1.output.len;
  63        if !overshoot.is_zero() {
  64            let transform = cursor.item().expect("display point out of range");
  65            assert!(transform.output_text.is_none());
  66            let end_buffer_offset = snapshot
  67                .buffer_snapshot
  68                .point_to_offset(cursor.start().1.input.lines + overshoot);
  69            offset += end_buffer_offset - cursor.start().1.input.len;
  70        }
  71        FoldOffset(offset)
  72    }
  73}
  74
  75impl<'a> sum_tree::Dimension<'a, TransformSummary> for FoldPoint {
  76    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
  77        self.0 += &summary.output.lines;
  78    }
  79}
  80
  81pub struct FoldMapWriter<'a>(&'a mut FoldMap);
  82
  83impl<'a> FoldMapWriter<'a> {
  84    pub fn fold<T: ToOffset>(
  85        &mut self,
  86        ranges: impl IntoIterator<Item = Range<T>>,
  87    ) -> (FoldSnapshot, Vec<FoldEdit>) {
  88        let mut edits = Vec::new();
  89        let mut folds = Vec::new();
  90        let buffer = self.0.buffer.lock().clone();
  91        for range in ranges.into_iter() {
  92            let range = range.start.to_offset(&buffer)..range.end.to_offset(&buffer);
  93
  94            // Ignore any empty ranges.
  95            if range.start == range.end {
  96                continue;
  97            }
  98
  99            // For now, ignore any ranges that span an excerpt boundary.
 100            let fold = Fold(buffer.anchor_after(range.start)..buffer.anchor_before(range.end));
 101            if fold.0.start.excerpt_id() != fold.0.end.excerpt_id() {
 102                continue;
 103            }
 104
 105            folds.push(fold);
 106            edits.push(text::Edit {
 107                old: range.clone(),
 108                new: range,
 109            });
 110        }
 111
 112        folds.sort_unstable_by(|a, b| sum_tree::SeekTarget::cmp(a, b, &buffer));
 113
 114        self.0.folds = {
 115            let mut new_tree = SumTree::new();
 116            let mut cursor = self.0.folds.cursor::<Fold>();
 117            for fold in folds {
 118                new_tree.append(cursor.slice(&fold, Bias::Right, &buffer), &buffer);
 119                new_tree.push(fold, &buffer);
 120            }
 121            new_tree.append(cursor.suffix(&buffer), &buffer);
 122            new_tree
 123        };
 124
 125        consolidate_buffer_edits(&mut edits);
 126        let edits = self.0.sync(buffer.clone(), edits);
 127        let snapshot = FoldSnapshot {
 128            transforms: self.0.transforms.lock().clone(),
 129            folds: self.0.folds.clone(),
 130            buffer_snapshot: buffer,
 131            version: self.0.version.load(SeqCst),
 132            ellipses_color: self.0.ellipses_color,
 133        };
 134        (snapshot, edits)
 135    }
 136
 137    pub fn unfold<T: ToOffset>(
 138        &mut self,
 139        ranges: impl IntoIterator<Item = Range<T>>,
 140        inclusive: bool,
 141    ) -> (FoldSnapshot, Vec<FoldEdit>) {
 142        let mut edits = Vec::new();
 143        let mut fold_ixs_to_delete = Vec::new();
 144        let buffer = self.0.buffer.lock().clone();
 145        for range in ranges.into_iter() {
 146            // Remove intersecting folds and add their ranges to edits that are passed to sync.
 147            let mut folds_cursor = intersecting_folds(&buffer, &self.0.folds, range, inclusive);
 148            while let Some(fold) = folds_cursor.item() {
 149                let offset_range = fold.0.start.to_offset(&buffer)..fold.0.end.to_offset(&buffer);
 150                if offset_range.end > offset_range.start {
 151                    edits.push(text::Edit {
 152                        old: offset_range.clone(),
 153                        new: offset_range,
 154                    });
 155                }
 156                fold_ixs_to_delete.push(*folds_cursor.start());
 157                folds_cursor.next(&buffer);
 158            }
 159        }
 160
 161        fold_ixs_to_delete.sort_unstable();
 162        fold_ixs_to_delete.dedup();
 163
 164        self.0.folds = {
 165            let mut cursor = self.0.folds.cursor::<usize>();
 166            let mut folds = SumTree::new();
 167            for fold_ix in fold_ixs_to_delete {
 168                folds.append(cursor.slice(&fold_ix, Bias::Right, &buffer), &buffer);
 169                cursor.next(&buffer);
 170            }
 171            folds.append(cursor.suffix(&buffer), &buffer);
 172            folds
 173        };
 174
 175        consolidate_buffer_edits(&mut edits);
 176        let edits = self.0.sync(buffer.clone(), edits);
 177        let snapshot = FoldSnapshot {
 178            transforms: self.0.transforms.lock().clone(),
 179            folds: self.0.folds.clone(),
 180            buffer_snapshot: buffer,
 181            version: self.0.version.load(SeqCst),
 182            ellipses_color: self.0.ellipses_color,
 183        };
 184        (snapshot, edits)
 185    }
 186}
 187
 188pub struct FoldMap {
 189    buffer: Mutex<MultiBufferSnapshot>,
 190    transforms: Mutex<SumTree<Transform>>,
 191    folds: SumTree<Fold>,
 192    version: AtomicUsize,
 193    ellipses_color: Option<Color>,
 194}
 195
 196impl FoldMap {
 197    pub fn new(buffer: MultiBufferSnapshot) -> (Self, FoldSnapshot) {
 198        let this = Self {
 199            buffer: Mutex::new(buffer.clone()),
 200            folds: Default::default(),
 201            transforms: Mutex::new(SumTree::from_item(
 202                Transform {
 203                    summary: TransformSummary {
 204                        input: buffer.text_summary(),
 205                        output: buffer.text_summary(),
 206                    },
 207                    output_text: None,
 208                },
 209                &(),
 210            )),
 211            ellipses_color: None,
 212            version: Default::default(),
 213        };
 214
 215        let snapshot = FoldSnapshot {
 216            transforms: this.transforms.lock().clone(),
 217            folds: this.folds.clone(),
 218            buffer_snapshot: this.buffer.lock().clone(),
 219            version: this.version.load(SeqCst),
 220            ellipses_color: None,
 221        };
 222        (this, snapshot)
 223    }
 224
 225    pub fn read(
 226        &self,
 227        buffer: MultiBufferSnapshot,
 228        edits: Vec<Edit<usize>>,
 229    ) -> (FoldSnapshot, Vec<FoldEdit>) {
 230        let edits = self.sync(buffer, edits);
 231        self.check_invariants();
 232        let snapshot = FoldSnapshot {
 233            transforms: self.transforms.lock().clone(),
 234            folds: self.folds.clone(),
 235            buffer_snapshot: self.buffer.lock().clone(),
 236            version: self.version.load(SeqCst),
 237            ellipses_color: self.ellipses_color,
 238        };
 239        (snapshot, edits)
 240    }
 241
 242    pub fn write(
 243        &mut self,
 244        buffer: MultiBufferSnapshot,
 245        edits: Vec<Edit<usize>>,
 246    ) -> (FoldMapWriter, FoldSnapshot, Vec<FoldEdit>) {
 247        let (snapshot, edits) = self.read(buffer, edits);
 248        (FoldMapWriter(self), snapshot, edits)
 249    }
 250
 251    pub fn set_ellipses_color(&mut self, color: Color) -> bool {
 252        if self.ellipses_color != Some(color) {
 253            self.ellipses_color = Some(color);
 254            true
 255        } else {
 256            false
 257        }
 258    }
 259
 260    fn check_invariants(&self) {
 261        if cfg!(test) {
 262            assert_eq!(
 263                self.transforms.lock().summary().input.len,
 264                self.buffer.lock().len(),
 265                "transform tree does not match buffer's length"
 266            );
 267
 268            let mut folds = self.folds.iter().peekable();
 269            while let Some(fold) = folds.next() {
 270                if let Some(next_fold) = folds.peek() {
 271                    let comparison = fold.0.cmp(&next_fold.0, &self.buffer.lock());
 272                    assert!(comparison.is_le());
 273                }
 274            }
 275        }
 276    }
 277
 278    fn sync(
 279        &self,
 280        new_buffer: MultiBufferSnapshot,
 281        buffer_edits: Vec<text::Edit<usize>>,
 282    ) -> Vec<FoldEdit> {
 283        if buffer_edits.is_empty() {
 284            let mut buffer = self.buffer.lock();
 285            if buffer.edit_count() != new_buffer.edit_count()
 286                || buffer.parse_count() != new_buffer.parse_count()
 287                || buffer.diagnostics_update_count() != new_buffer.diagnostics_update_count()
 288                || buffer.git_diff_update_count() != new_buffer.git_diff_update_count()
 289                || buffer.trailing_excerpt_update_count()
 290                    != new_buffer.trailing_excerpt_update_count()
 291            {
 292                self.version.fetch_add(1, SeqCst);
 293            }
 294            *buffer = new_buffer;
 295            Vec::new()
 296        } else {
 297            let mut buffer_edits_iter = buffer_edits.iter().cloned().peekable();
 298
 299            let mut new_transforms = SumTree::new();
 300            let mut transforms = self.transforms.lock();
 301            let mut cursor = transforms.cursor::<usize>();
 302            cursor.seek(&0, Bias::Right, &());
 303
 304            while let Some(mut edit) = buffer_edits_iter.next() {
 305                new_transforms.append(cursor.slice(&edit.old.start, Bias::Left, &()), &());
 306                edit.new.start -= edit.old.start - cursor.start();
 307                edit.old.start = *cursor.start();
 308
 309                cursor.seek(&edit.old.end, Bias::Right, &());
 310                cursor.next(&());
 311
 312                let mut delta = edit.new.len() as isize - edit.old.len() as isize;
 313                loop {
 314                    edit.old.end = *cursor.start();
 315
 316                    if let Some(next_edit) = buffer_edits_iter.peek() {
 317                        if next_edit.old.start > edit.old.end {
 318                            break;
 319                        }
 320
 321                        let next_edit = buffer_edits_iter.next().unwrap();
 322                        delta += next_edit.new.len() as isize - next_edit.old.len() as isize;
 323
 324                        if next_edit.old.end >= edit.old.end {
 325                            edit.old.end = next_edit.old.end;
 326                            cursor.seek(&edit.old.end, Bias::Right, &());
 327                            cursor.next(&());
 328                        }
 329                    } else {
 330                        break;
 331                    }
 332                }
 333
 334                edit.new.end = ((edit.new.start + edit.old.len()) as isize + delta) as usize;
 335
 336                let anchor = new_buffer.anchor_before(edit.new.start);
 337                let mut folds_cursor = self.folds.cursor::<Fold>();
 338                folds_cursor.seek(&Fold(anchor..Anchor::max()), Bias::Left, &new_buffer);
 339
 340                let mut folds = iter::from_fn({
 341                    let buffer = &new_buffer;
 342                    move || {
 343                        let item = folds_cursor
 344                            .item()
 345                            .map(|f| f.0.start.to_offset(buffer)..f.0.end.to_offset(buffer));
 346                        folds_cursor.next(buffer);
 347                        item
 348                    }
 349                })
 350                .peekable();
 351
 352                while folds.peek().map_or(false, |fold| fold.start < edit.new.end) {
 353                    let mut fold = folds.next().unwrap();
 354                    let sum = new_transforms.summary();
 355
 356                    assert!(fold.start >= sum.input.len);
 357
 358                    while folds
 359                        .peek()
 360                        .map_or(false, |next_fold| next_fold.start <= fold.end)
 361                    {
 362                        let next_fold = folds.next().unwrap();
 363                        if next_fold.end > fold.end {
 364                            fold.end = next_fold.end;
 365                        }
 366                    }
 367
 368                    if fold.start > sum.input.len {
 369                        let text_summary = new_buffer
 370                            .text_summary_for_range::<TextSummary, _>(sum.input.len..fold.start);
 371                        new_transforms.push(
 372                            Transform {
 373                                summary: TransformSummary {
 374                                    output: text_summary.clone(),
 375                                    input: text_summary,
 376                                },
 377                                output_text: None,
 378                            },
 379                            &(),
 380                        );
 381                    }
 382
 383                    if fold.end > fold.start {
 384                        let output_text = "⋯";
 385                        new_transforms.push(
 386                            Transform {
 387                                summary: TransformSummary {
 388                                    output: TextSummary::from(output_text),
 389                                    input: new_buffer.text_summary_for_range(fold.start..fold.end),
 390                                },
 391                                output_text: Some(output_text),
 392                            },
 393                            &(),
 394                        );
 395                    }
 396                }
 397
 398                let sum = new_transforms.summary();
 399                if sum.input.len < edit.new.end {
 400                    let text_summary = new_buffer
 401                        .text_summary_for_range::<TextSummary, _>(sum.input.len..edit.new.end);
 402                    new_transforms.push(
 403                        Transform {
 404                            summary: TransformSummary {
 405                                output: text_summary.clone(),
 406                                input: text_summary,
 407                            },
 408                            output_text: None,
 409                        },
 410                        &(),
 411                    );
 412                }
 413            }
 414
 415            new_transforms.append(cursor.suffix(&()), &());
 416            if new_transforms.is_empty() {
 417                let text_summary = new_buffer.text_summary();
 418                new_transforms.push(
 419                    Transform {
 420                        summary: TransformSummary {
 421                            output: text_summary.clone(),
 422                            input: text_summary,
 423                        },
 424                        output_text: None,
 425                    },
 426                    &(),
 427                );
 428            }
 429
 430            drop(cursor);
 431
 432            let mut fold_edits = Vec::with_capacity(buffer_edits.len());
 433            {
 434                let mut old_transforms = transforms.cursor::<(usize, FoldOffset)>();
 435                let mut new_transforms = new_transforms.cursor::<(usize, FoldOffset)>();
 436
 437                for mut edit in buffer_edits {
 438                    old_transforms.seek(&edit.old.start, Bias::Left, &());
 439                    if old_transforms.item().map_or(false, |t| t.is_fold()) {
 440                        edit.old.start = old_transforms.start().0;
 441                    }
 442                    let old_start =
 443                        old_transforms.start().1 .0 + (edit.old.start - old_transforms.start().0);
 444
 445                    old_transforms.seek_forward(&edit.old.end, Bias::Right, &());
 446                    if old_transforms.item().map_or(false, |t| t.is_fold()) {
 447                        old_transforms.next(&());
 448                        edit.old.end = old_transforms.start().0;
 449                    }
 450                    let old_end =
 451                        old_transforms.start().1 .0 + (edit.old.end - old_transforms.start().0);
 452
 453                    new_transforms.seek(&edit.new.start, Bias::Left, &());
 454                    if new_transforms.item().map_or(false, |t| t.is_fold()) {
 455                        edit.new.start = new_transforms.start().0;
 456                    }
 457                    let new_start =
 458                        new_transforms.start().1 .0 + (edit.new.start - new_transforms.start().0);
 459
 460                    new_transforms.seek_forward(&edit.new.end, Bias::Right, &());
 461                    if new_transforms.item().map_or(false, |t| t.is_fold()) {
 462                        new_transforms.next(&());
 463                        edit.new.end = new_transforms.start().0;
 464                    }
 465                    let new_end =
 466                        new_transforms.start().1 .0 + (edit.new.end - new_transforms.start().0);
 467
 468                    fold_edits.push(FoldEdit {
 469                        old: FoldOffset(old_start)..FoldOffset(old_end),
 470                        new: FoldOffset(new_start)..FoldOffset(new_end),
 471                    });
 472                }
 473
 474                consolidate_fold_edits(&mut fold_edits);
 475            }
 476
 477            *transforms = new_transforms;
 478            *self.buffer.lock() = new_buffer;
 479            self.version.fetch_add(1, SeqCst);
 480            fold_edits
 481        }
 482    }
 483}
 484
 485#[derive(Clone)]
 486pub struct FoldSnapshot {
 487    transforms: SumTree<Transform>,
 488    folds: SumTree<Fold>,
 489    buffer_snapshot: MultiBufferSnapshot,
 490    pub version: usize,
 491    pub ellipses_color: Option<Color>,
 492}
 493
 494impl FoldSnapshot {
 495    pub fn buffer_snapshot(&self) -> &MultiBufferSnapshot {
 496        &self.buffer_snapshot
 497    }
 498
 499    #[cfg(test)]
 500    pub fn text(&self) -> String {
 501        self.chunks(FoldOffset(0)..self.len(), false, None)
 502            .map(|c| c.text)
 503            .collect()
 504    }
 505
 506    #[cfg(test)]
 507    pub fn fold_count(&self) -> usize {
 508        self.folds.items(&self.buffer_snapshot).len()
 509    }
 510
 511    pub fn text_summary(&self) -> TextSummary {
 512        self.transforms.summary().output.clone()
 513    }
 514
 515    pub fn text_summary_for_range(&self, range: Range<FoldPoint>) -> TextSummary {
 516        let mut summary = TextSummary::default();
 517
 518        let mut cursor = self.transforms.cursor::<(FoldPoint, Point)>();
 519        cursor.seek(&range.start, Bias::Right, &());
 520        if let Some(transform) = cursor.item() {
 521            let start_in_transform = range.start.0 - cursor.start().0 .0;
 522            let end_in_transform = cmp::min(range.end, cursor.end(&()).0).0 - cursor.start().0 .0;
 523            if let Some(output_text) = transform.output_text {
 524                summary = TextSummary::from(
 525                    &output_text
 526                        [start_in_transform.column as usize..end_in_transform.column as usize],
 527                );
 528            } else {
 529                let buffer_start = cursor.start().1 + start_in_transform;
 530                let buffer_end = cursor.start().1 + end_in_transform;
 531                summary = self
 532                    .buffer_snapshot
 533                    .text_summary_for_range(buffer_start..buffer_end);
 534            }
 535        }
 536
 537        if range.end > cursor.end(&()).0 {
 538            cursor.next(&());
 539            summary += &cursor
 540                .summary::<_, TransformSummary>(&range.end, Bias::Right, &())
 541                .output;
 542            if let Some(transform) = cursor.item() {
 543                let end_in_transform = range.end.0 - cursor.start().0 .0;
 544                if let Some(output_text) = transform.output_text {
 545                    summary += TextSummary::from(&output_text[..end_in_transform.column as usize]);
 546                } else {
 547                    let buffer_start = cursor.start().1;
 548                    let buffer_end = cursor.start().1 + end_in_transform;
 549                    summary += self
 550                        .buffer_snapshot
 551                        .text_summary_for_range::<TextSummary, _>(buffer_start..buffer_end);
 552                }
 553            }
 554        }
 555
 556        summary
 557    }
 558
 559    pub fn to_fold_point(&self, point: Point, bias: Bias) -> FoldPoint {
 560        let mut cursor = self.transforms.cursor::<(Point, FoldPoint)>();
 561        cursor.seek(&point, Bias::Right, &());
 562        if cursor.item().map_or(false, |t| t.is_fold()) {
 563            if bias == Bias::Left || point == cursor.start().0 {
 564                cursor.start().1
 565            } else {
 566                cursor.end(&()).1
 567            }
 568        } else {
 569            let overshoot = point - cursor.start().0;
 570            FoldPoint(cmp::min(
 571                cursor.start().1 .0 + overshoot,
 572                cursor.end(&()).1 .0,
 573            ))
 574        }
 575    }
 576
 577    pub fn len(&self) -> FoldOffset {
 578        FoldOffset(self.transforms.summary().output.len)
 579    }
 580
 581    pub fn line_len(&self, row: u32) -> u32 {
 582        let line_start = FoldPoint::new(row, 0).to_offset(self).0;
 583        let line_end = if row >= self.max_point().row() {
 584            self.len().0
 585        } else {
 586            FoldPoint::new(row + 1, 0).to_offset(self).0 - 1
 587        };
 588        (line_end - line_start) as u32
 589    }
 590
 591    pub fn buffer_rows(&self, start_row: u32) -> FoldBufferRows {
 592        if start_row > self.transforms.summary().output.lines.row {
 593            panic!("invalid display row {}", start_row);
 594        }
 595
 596        let fold_point = FoldPoint::new(start_row, 0);
 597        let mut cursor = self.transforms.cursor::<(FoldPoint, Point)>();
 598        cursor.seek(&fold_point, Bias::Left, &());
 599
 600        let overshoot = fold_point.0 - cursor.start().0 .0;
 601        let buffer_point = cursor.start().1 + overshoot;
 602        let input_buffer_rows = self.buffer_snapshot.buffer_rows(buffer_point.row);
 603
 604        FoldBufferRows {
 605            fold_point,
 606            input_buffer_rows,
 607            cursor,
 608        }
 609    }
 610
 611    pub fn max_point(&self) -> FoldPoint {
 612        FoldPoint(self.transforms.summary().output.lines)
 613    }
 614
 615    #[cfg(test)]
 616    pub fn longest_row(&self) -> u32 {
 617        self.transforms.summary().output.longest_row
 618    }
 619
 620    pub fn folds_in_range<T>(&self, range: Range<T>) -> impl Iterator<Item = &Range<Anchor>>
 621    where
 622        T: ToOffset,
 623    {
 624        let mut folds = intersecting_folds(&self.buffer_snapshot, &self.folds, range, false);
 625        iter::from_fn(move || {
 626            let item = folds.item().map(|f| &f.0);
 627            folds.next(&self.buffer_snapshot);
 628            item
 629        })
 630    }
 631
 632    pub fn intersects_fold<T>(&self, offset: T) -> bool
 633    where
 634        T: ToOffset,
 635    {
 636        let offset = offset.to_offset(&self.buffer_snapshot);
 637        let mut cursor = self.transforms.cursor::<usize>();
 638        cursor.seek(&offset, Bias::Right, &());
 639        cursor.item().map_or(false, |t| t.output_text.is_some())
 640    }
 641
 642    pub fn is_line_folded(&self, buffer_row: u32) -> bool {
 643        let mut cursor = self.transforms.cursor::<Point>();
 644        cursor.seek(&Point::new(buffer_row, 0), Bias::Right, &());
 645        while let Some(transform) = cursor.item() {
 646            if transform.output_text.is_some() {
 647                return true;
 648            }
 649            if cursor.end(&()).row == buffer_row {
 650                cursor.next(&())
 651            } else {
 652                break;
 653            }
 654        }
 655        false
 656    }
 657
 658    pub fn chunks<'a>(
 659        &'a self,
 660        range: Range<FoldOffset>,
 661        language_aware: bool,
 662        text_highlights: Option<&'a TextHighlights>,
 663    ) -> FoldChunks<'a> {
 664        let mut highlight_endpoints = Vec::new();
 665        let mut transform_cursor = self.transforms.cursor::<(FoldOffset, usize)>();
 666
 667        let buffer_end = {
 668            transform_cursor.seek(&range.end, Bias::Right, &());
 669            let overshoot = range.end.0 - transform_cursor.start().0 .0;
 670            transform_cursor.start().1 + overshoot
 671        };
 672
 673        let buffer_start = {
 674            transform_cursor.seek(&range.start, Bias::Right, &());
 675            let overshoot = range.start.0 - transform_cursor.start().0 .0;
 676            transform_cursor.start().1 + overshoot
 677        };
 678
 679        if let Some(text_highlights) = text_highlights {
 680            if !text_highlights.is_empty() {
 681                while transform_cursor.start().0 < range.end {
 682                    if !transform_cursor.item().unwrap().is_fold() {
 683                        let transform_start = self
 684                            .buffer_snapshot
 685                            .anchor_after(cmp::max(buffer_start, transform_cursor.start().1));
 686
 687                        let transform_end = {
 688                            let overshoot = range.end.0 - transform_cursor.start().0 .0;
 689                            self.buffer_snapshot.anchor_before(cmp::min(
 690                                transform_cursor.end(&()).1,
 691                                transform_cursor.start().1 + overshoot,
 692                            ))
 693                        };
 694
 695                        for (tag, highlights) in text_highlights.iter() {
 696                            let style = highlights.0;
 697                            let ranges = &highlights.1;
 698
 699                            let start_ix = match ranges.binary_search_by(|probe| {
 700                                let cmp = probe.end.cmp(&transform_start, self.buffer_snapshot());
 701                                if cmp.is_gt() {
 702                                    Ordering::Greater
 703                                } else {
 704                                    Ordering::Less
 705                                }
 706                            }) {
 707                                Ok(i) | Err(i) => i,
 708                            };
 709                            for range in &ranges[start_ix..] {
 710                                if range
 711                                    .start
 712                                    .cmp(&transform_end, &self.buffer_snapshot)
 713                                    .is_ge()
 714                                {
 715                                    break;
 716                                }
 717
 718                                highlight_endpoints.push(HighlightEndpoint {
 719                                    offset: range.start.to_offset(&self.buffer_snapshot),
 720                                    is_start: true,
 721                                    tag: *tag,
 722                                    style,
 723                                });
 724                                highlight_endpoints.push(HighlightEndpoint {
 725                                    offset: range.end.to_offset(&self.buffer_snapshot),
 726                                    is_start: false,
 727                                    tag: *tag,
 728                                    style,
 729                                });
 730                            }
 731                        }
 732                    }
 733
 734                    transform_cursor.next(&());
 735                }
 736                highlight_endpoints.sort();
 737                transform_cursor.seek(&range.start, Bias::Right, &());
 738            }
 739        }
 740
 741        FoldChunks {
 742            transform_cursor,
 743            buffer_chunks: self
 744                .buffer_snapshot
 745                .chunks(buffer_start..buffer_end, language_aware),
 746            buffer_chunk: None,
 747            buffer_offset: buffer_start,
 748            output_offset: range.start.0,
 749            max_output_offset: range.end.0,
 750            highlight_endpoints: highlight_endpoints.into_iter().peekable(),
 751            active_highlights: Default::default(),
 752            ellipses_color: self.ellipses_color,
 753        }
 754    }
 755
 756    #[cfg(test)]
 757    pub fn clip_offset(&self, offset: FoldOffset, bias: Bias) -> FoldOffset {
 758        let mut cursor = self.transforms.cursor::<(FoldOffset, usize)>();
 759        cursor.seek(&offset, Bias::Right, &());
 760        if let Some(transform) = cursor.item() {
 761            let transform_start = cursor.start().0 .0;
 762            if transform.output_text.is_some() {
 763                if offset.0 == transform_start || matches!(bias, Bias::Left) {
 764                    FoldOffset(transform_start)
 765                } else {
 766                    FoldOffset(cursor.end(&()).0 .0)
 767                }
 768            } else {
 769                let overshoot = offset.0 - transform_start;
 770                let buffer_offset = cursor.start().1 + overshoot;
 771                let clipped_buffer_offset = self.buffer_snapshot.clip_offset(buffer_offset, bias);
 772                FoldOffset(
 773                    (offset.0 as isize + (clipped_buffer_offset as isize - buffer_offset as isize))
 774                        as usize,
 775                )
 776            }
 777        } else {
 778            FoldOffset(self.transforms.summary().output.len)
 779        }
 780    }
 781
 782    pub fn clip_point(&self, point: FoldPoint, bias: Bias) -> FoldPoint {
 783        let mut cursor = self.transforms.cursor::<(FoldPoint, Point)>();
 784        cursor.seek(&point, Bias::Right, &());
 785        if let Some(transform) = cursor.item() {
 786            let transform_start = cursor.start().0 .0;
 787            if transform.output_text.is_some() {
 788                if point.0 == transform_start || matches!(bias, Bias::Left) {
 789                    FoldPoint(transform_start)
 790                } else {
 791                    FoldPoint(cursor.end(&()).0 .0)
 792                }
 793            } else {
 794                let overshoot = point.0 - transform_start;
 795                let buffer_position = cursor.start().1 + overshoot;
 796                let clipped_buffer_position =
 797                    self.buffer_snapshot.clip_point(buffer_position, bias);
 798                FoldPoint(cursor.start().0 .0 + (clipped_buffer_position - cursor.start().1))
 799            }
 800        } else {
 801            FoldPoint(self.transforms.summary().output.lines)
 802        }
 803    }
 804}
 805
 806fn intersecting_folds<'a, T>(
 807    buffer: &'a MultiBufferSnapshot,
 808    folds: &'a SumTree<Fold>,
 809    range: Range<T>,
 810    inclusive: bool,
 811) -> FilterCursor<'a, impl 'a + FnMut(&FoldSummary) -> bool, Fold, usize>
 812where
 813    T: ToOffset,
 814{
 815    let start = buffer.anchor_before(range.start.to_offset(buffer));
 816    let end = buffer.anchor_after(range.end.to_offset(buffer));
 817    let mut cursor = folds.filter::<_, usize>(move |summary| {
 818        let start_cmp = start.cmp(&summary.max_end, buffer);
 819        let end_cmp = end.cmp(&summary.min_start, buffer);
 820
 821        if inclusive {
 822            start_cmp <= Ordering::Equal && end_cmp >= Ordering::Equal
 823        } else {
 824            start_cmp == Ordering::Less && end_cmp == Ordering::Greater
 825        }
 826    });
 827    cursor.next(buffer);
 828    cursor
 829}
 830
 831fn consolidate_buffer_edits(edits: &mut Vec<text::Edit<usize>>) {
 832    edits.sort_unstable_by(|a, b| {
 833        a.old
 834            .start
 835            .cmp(&b.old.start)
 836            .then_with(|| b.old.end.cmp(&a.old.end))
 837    });
 838
 839    let mut i = 1;
 840    while i < edits.len() {
 841        let edit = edits[i].clone();
 842        let prev_edit = &mut edits[i - 1];
 843        if prev_edit.old.end >= edit.old.start {
 844            prev_edit.old.end = prev_edit.old.end.max(edit.old.end);
 845            prev_edit.new.start = prev_edit.new.start.min(edit.new.start);
 846            prev_edit.new.end = prev_edit.new.end.max(edit.new.end);
 847            edits.remove(i);
 848            continue;
 849        }
 850        i += 1;
 851    }
 852}
 853
 854fn consolidate_fold_edits(edits: &mut Vec<FoldEdit>) {
 855    edits.sort_unstable_by(|a, b| {
 856        a.old
 857            .start
 858            .cmp(&b.old.start)
 859            .then_with(|| b.old.end.cmp(&a.old.end))
 860    });
 861
 862    let mut i = 1;
 863    while i < edits.len() {
 864        let edit = edits[i].clone();
 865        let prev_edit = &mut edits[i - 1];
 866        if prev_edit.old.end >= edit.old.start {
 867            prev_edit.old.end = prev_edit.old.end.max(edit.old.end);
 868            prev_edit.new.start = prev_edit.new.start.min(edit.new.start);
 869            prev_edit.new.end = prev_edit.new.end.max(edit.new.end);
 870            edits.remove(i);
 871            continue;
 872        }
 873        i += 1;
 874    }
 875}
 876
 877#[derive(Clone, Debug, Default, Eq, PartialEq)]
 878struct Transform {
 879    summary: TransformSummary,
 880    output_text: Option<&'static str>,
 881}
 882
 883impl Transform {
 884    fn is_fold(&self) -> bool {
 885        self.output_text.is_some()
 886    }
 887}
 888
 889#[derive(Clone, Debug, Default, Eq, PartialEq)]
 890struct TransformSummary {
 891    output: TextSummary,
 892    input: TextSummary,
 893}
 894
 895impl sum_tree::Item for Transform {
 896    type Summary = TransformSummary;
 897
 898    fn summary(&self) -> Self::Summary {
 899        self.summary.clone()
 900    }
 901}
 902
 903impl sum_tree::Summary for TransformSummary {
 904    type Context = ();
 905
 906    fn add_summary(&mut self, other: &Self, _: &()) {
 907        self.input += &other.input;
 908        self.output += &other.output;
 909    }
 910}
 911
 912#[derive(Clone, Debug)]
 913struct Fold(Range<Anchor>);
 914
 915impl Default for Fold {
 916    fn default() -> Self {
 917        Self(Anchor::min()..Anchor::max())
 918    }
 919}
 920
 921impl sum_tree::Item for Fold {
 922    type Summary = FoldSummary;
 923
 924    fn summary(&self) -> Self::Summary {
 925        FoldSummary {
 926            start: self.0.start.clone(),
 927            end: self.0.end.clone(),
 928            min_start: self.0.start.clone(),
 929            max_end: self.0.end.clone(),
 930            count: 1,
 931        }
 932    }
 933}
 934
 935#[derive(Clone, Debug)]
 936struct FoldSummary {
 937    start: Anchor,
 938    end: Anchor,
 939    min_start: Anchor,
 940    max_end: Anchor,
 941    count: usize,
 942}
 943
 944impl Default for FoldSummary {
 945    fn default() -> Self {
 946        Self {
 947            start: Anchor::min(),
 948            end: Anchor::max(),
 949            min_start: Anchor::max(),
 950            max_end: Anchor::min(),
 951            count: 0,
 952        }
 953    }
 954}
 955
 956impl sum_tree::Summary for FoldSummary {
 957    type Context = MultiBufferSnapshot;
 958
 959    fn add_summary(&mut self, other: &Self, buffer: &MultiBufferSnapshot) {
 960        if other.min_start.cmp(&self.min_start, buffer) == Ordering::Less {
 961            self.min_start = other.min_start.clone();
 962        }
 963        if other.max_end.cmp(&self.max_end, buffer) == Ordering::Greater {
 964            self.max_end = other.max_end.clone();
 965        }
 966
 967        #[cfg(debug_assertions)]
 968        {
 969            let start_comparison = self.start.cmp(&other.start, buffer);
 970            assert!(start_comparison <= Ordering::Equal);
 971            if start_comparison == Ordering::Equal {
 972                assert!(self.end.cmp(&other.end, buffer) >= Ordering::Equal);
 973            }
 974        }
 975
 976        self.start = other.start.clone();
 977        self.end = other.end.clone();
 978        self.count += other.count;
 979    }
 980}
 981
 982impl<'a> sum_tree::Dimension<'a, FoldSummary> for Fold {
 983    fn add_summary(&mut self, summary: &'a FoldSummary, _: &MultiBufferSnapshot) {
 984        self.0.start = summary.start.clone();
 985        self.0.end = summary.end.clone();
 986    }
 987}
 988
 989impl<'a> sum_tree::SeekTarget<'a, FoldSummary, Fold> for Fold {
 990    fn cmp(&self, other: &Self, buffer: &MultiBufferSnapshot) -> Ordering {
 991        self.0.cmp(&other.0, buffer)
 992    }
 993}
 994
 995impl<'a> sum_tree::Dimension<'a, FoldSummary> for usize {
 996    fn add_summary(&mut self, summary: &'a FoldSummary, _: &MultiBufferSnapshot) {
 997        *self += summary.count;
 998    }
 999}
1000
1001#[derive(Clone)]
1002pub struct FoldBufferRows<'a> {
1003    cursor: Cursor<'a, Transform, (FoldPoint, Point)>,
1004    input_buffer_rows: MultiBufferRows<'a>,
1005    fold_point: FoldPoint,
1006}
1007
1008impl<'a> Iterator for FoldBufferRows<'a> {
1009    type Item = Option<u32>;
1010
1011    fn next(&mut self) -> Option<Self::Item> {
1012        let mut traversed_fold = false;
1013        while self.fold_point > self.cursor.end(&()).0 {
1014            self.cursor.next(&());
1015            traversed_fold = true;
1016            if self.cursor.item().is_none() {
1017                break;
1018            }
1019        }
1020
1021        if self.cursor.item().is_some() {
1022            if traversed_fold {
1023                self.input_buffer_rows.seek(self.cursor.start().1.row);
1024                self.input_buffer_rows.next();
1025            }
1026            *self.fold_point.row_mut() += 1;
1027            self.input_buffer_rows.next()
1028        } else {
1029            None
1030        }
1031    }
1032}
1033
1034pub struct FoldChunks<'a> {
1035    transform_cursor: Cursor<'a, Transform, (FoldOffset, usize)>,
1036    buffer_chunks: MultiBufferChunks<'a>,
1037    buffer_chunk: Option<(usize, Chunk<'a>)>,
1038    buffer_offset: usize,
1039    output_offset: usize,
1040    max_output_offset: usize,
1041    highlight_endpoints: Peekable<vec::IntoIter<HighlightEndpoint>>,
1042    active_highlights: BTreeMap<Option<TypeId>, HighlightStyle>,
1043    ellipses_color: Option<Color>,
1044}
1045
1046impl<'a> Iterator for FoldChunks<'a> {
1047    type Item = Chunk<'a>;
1048
1049    fn next(&mut self) -> Option<Self::Item> {
1050        if self.output_offset >= self.max_output_offset {
1051            return None;
1052        }
1053
1054        let transform = self.transform_cursor.item()?;
1055
1056        // If we're in a fold, then return the fold's display text and
1057        // advance the transform and buffer cursors to the end of the fold.
1058        if let Some(output_text) = transform.output_text {
1059            self.buffer_chunk.take();
1060            self.buffer_offset += transform.summary.input.len;
1061            self.buffer_chunks.seek(self.buffer_offset);
1062
1063            while self.buffer_offset >= self.transform_cursor.end(&()).1
1064                && self.transform_cursor.item().is_some()
1065            {
1066                self.transform_cursor.next(&());
1067            }
1068
1069            self.output_offset += output_text.len();
1070            return Some(Chunk {
1071                text: output_text,
1072                highlight_style: self.ellipses_color.map(|color| HighlightStyle {
1073                    color: Some(color),
1074                    ..Default::default()
1075                }),
1076                ..Default::default()
1077            });
1078        }
1079
1080        let mut next_highlight_endpoint = usize::MAX;
1081        while let Some(endpoint) = self.highlight_endpoints.peek().copied() {
1082            if endpoint.offset <= self.buffer_offset {
1083                if endpoint.is_start {
1084                    self.active_highlights.insert(endpoint.tag, endpoint.style);
1085                } else {
1086                    self.active_highlights.remove(&endpoint.tag);
1087                }
1088                self.highlight_endpoints.next();
1089            } else {
1090                next_highlight_endpoint = endpoint.offset;
1091                break;
1092            }
1093        }
1094
1095        // Retrieve a chunk from the current location in the buffer.
1096        if self.buffer_chunk.is_none() {
1097            let chunk_offset = self.buffer_chunks.offset();
1098            self.buffer_chunk = self.buffer_chunks.next().map(|chunk| (chunk_offset, chunk));
1099        }
1100
1101        // Otherwise, take a chunk from the buffer's text.
1102        if let Some((buffer_chunk_start, mut chunk)) = self.buffer_chunk {
1103            let buffer_chunk_end = buffer_chunk_start + chunk.text.len();
1104            let transform_end = self.transform_cursor.end(&()).1;
1105            let chunk_end = buffer_chunk_end
1106                .min(transform_end)
1107                .min(next_highlight_endpoint);
1108
1109            chunk.text = &chunk.text
1110                [self.buffer_offset - buffer_chunk_start..chunk_end - buffer_chunk_start];
1111
1112            if !self.active_highlights.is_empty() {
1113                let mut highlight_style = HighlightStyle::default();
1114                for active_highlight in self.active_highlights.values() {
1115                    highlight_style.highlight(*active_highlight);
1116                }
1117                chunk.highlight_style = Some(highlight_style);
1118            }
1119
1120            if chunk_end == transform_end {
1121                self.transform_cursor.next(&());
1122            } else if chunk_end == buffer_chunk_end {
1123                self.buffer_chunk.take();
1124            }
1125
1126            self.buffer_offset = chunk_end;
1127            self.output_offset += chunk.text.len();
1128            return Some(chunk);
1129        }
1130
1131        None
1132    }
1133}
1134
1135#[derive(Copy, Clone, Eq, PartialEq)]
1136struct HighlightEndpoint {
1137    offset: usize,
1138    is_start: bool,
1139    tag: Option<TypeId>,
1140    style: HighlightStyle,
1141}
1142
1143impl PartialOrd for HighlightEndpoint {
1144    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
1145        Some(self.cmp(other))
1146    }
1147}
1148
1149impl Ord for HighlightEndpoint {
1150    fn cmp(&self, other: &Self) -> Ordering {
1151        self.offset
1152            .cmp(&other.offset)
1153            .then_with(|| other.is_start.cmp(&self.is_start))
1154    }
1155}
1156
1157#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
1158pub struct FoldOffset(pub usize);
1159
1160impl FoldOffset {
1161    pub fn to_point(self, snapshot: &FoldSnapshot) -> FoldPoint {
1162        let mut cursor = snapshot
1163            .transforms
1164            .cursor::<(FoldOffset, TransformSummary)>();
1165        cursor.seek(&self, Bias::Right, &());
1166        let overshoot = if cursor.item().map_or(true, |t| t.is_fold()) {
1167            Point::new(0, (self.0 - cursor.start().0 .0) as u32)
1168        } else {
1169            let buffer_offset = cursor.start().1.input.len + self.0 - cursor.start().0 .0;
1170            let buffer_point = snapshot.buffer_snapshot.offset_to_point(buffer_offset);
1171            buffer_point - cursor.start().1.input.lines
1172        };
1173        FoldPoint(cursor.start().1.output.lines + overshoot)
1174    }
1175}
1176
1177impl Add for FoldOffset {
1178    type Output = Self;
1179
1180    fn add(self, rhs: Self) -> Self::Output {
1181        Self(self.0 + rhs.0)
1182    }
1183}
1184
1185impl AddAssign for FoldOffset {
1186    fn add_assign(&mut self, rhs: Self) {
1187        self.0 += rhs.0;
1188    }
1189}
1190
1191impl Sub for FoldOffset {
1192    type Output = Self;
1193
1194    fn sub(self, rhs: Self) -> Self::Output {
1195        Self(self.0 - rhs.0)
1196    }
1197}
1198
1199impl<'a> sum_tree::Dimension<'a, TransformSummary> for FoldOffset {
1200    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1201        self.0 += &summary.output.len;
1202    }
1203}
1204
1205impl<'a> sum_tree::Dimension<'a, TransformSummary> for Point {
1206    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1207        *self += &summary.input.lines;
1208    }
1209}
1210
1211impl<'a> sum_tree::Dimension<'a, TransformSummary> for usize {
1212    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
1213        *self += &summary.input.len;
1214    }
1215}
1216
1217pub type FoldEdit = Edit<FoldOffset>;
1218
1219#[cfg(test)]
1220mod tests {
1221    use super::*;
1222    use crate::{MultiBuffer, ToPoint};
1223    use collections::HashSet;
1224    use rand::prelude::*;
1225    use settings::SettingsStore;
1226    use std::{cmp::Reverse, env, mem, sync::Arc};
1227    use sum_tree::TreeMap;
1228    use util::test::sample_text;
1229    use util::RandomCharIter;
1230    use Bias::{Left, Right};
1231
1232    #[gpui::test]
1233    fn test_basic_folds(cx: &mut gpui::AppContext) {
1234        init_test(cx);
1235        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1236        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1237        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1238        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1239
1240        let (mut writer, _, _) = map.write(buffer_snapshot, vec![]);
1241        let (snapshot2, edits) = writer.fold(vec![
1242            Point::new(0, 2)..Point::new(2, 2),
1243            Point::new(2, 4)..Point::new(4, 1),
1244        ]);
1245        assert_eq!(snapshot2.text(), "aa⋯cc⋯eeeee");
1246        assert_eq!(
1247            edits,
1248            &[
1249                FoldEdit {
1250                    old: FoldOffset(2)..FoldOffset(16),
1251                    new: FoldOffset(2)..FoldOffset(5),
1252                },
1253                FoldEdit {
1254                    old: FoldOffset(18)..FoldOffset(29),
1255                    new: FoldOffset(7)..FoldOffset(10)
1256                },
1257            ]
1258        );
1259
1260        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1261            buffer.edit(
1262                vec![
1263                    (Point::new(0, 0)..Point::new(0, 1), "123"),
1264                    (Point::new(2, 3)..Point::new(2, 3), "123"),
1265                ],
1266                None,
1267                cx,
1268            );
1269            buffer.snapshot(cx)
1270        });
1271        let (snapshot3, edits) = map.read(buffer_snapshot, subscription.consume().into_inner());
1272        assert_eq!(snapshot3.text(), "123a⋯c123c⋯eeeee");
1273        assert_eq!(
1274            edits,
1275            &[
1276                FoldEdit {
1277                    old: FoldOffset(0)..FoldOffset(1),
1278                    new: FoldOffset(0)..FoldOffset(3),
1279                },
1280                FoldEdit {
1281                    old: FoldOffset(6)..FoldOffset(6),
1282                    new: FoldOffset(8)..FoldOffset(11),
1283                },
1284            ]
1285        );
1286
1287        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1288            buffer.edit([(Point::new(2, 6)..Point::new(4, 3), "456")], None, cx);
1289            buffer.snapshot(cx)
1290        });
1291        let (snapshot4, _) = map.read(buffer_snapshot.clone(), subscription.consume().into_inner());
1292        assert_eq!(snapshot4.text(), "123a⋯c123456eee");
1293
1294        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1295        writer.unfold(Some(Point::new(0, 4)..Point::new(0, 4)), false);
1296        let (snapshot5, _) = map.read(buffer_snapshot.clone(), vec![]);
1297        assert_eq!(snapshot5.text(), "123a⋯c123456eee");
1298
1299        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1300        writer.unfold(Some(Point::new(0, 4)..Point::new(0, 4)), true);
1301        let (snapshot6, _) = map.read(buffer_snapshot, vec![]);
1302        assert_eq!(snapshot6.text(), "123aaaaa\nbbbbbb\nccc123456eee");
1303    }
1304
1305    #[gpui::test]
1306    fn test_adjacent_folds(cx: &mut gpui::AppContext) {
1307        init_test(cx);
1308        let buffer = MultiBuffer::build_simple("abcdefghijkl", cx);
1309        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1310        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1311
1312        {
1313            let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1314
1315            let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1316            writer.fold(vec![5..8]);
1317            let (snapshot, _) = map.read(buffer_snapshot.clone(), vec![]);
1318            assert_eq!(snapshot.text(), "abcde⋯ijkl");
1319
1320            // Create an fold adjacent to the start of the first fold.
1321            let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1322            writer.fold(vec![0..1, 2..5]);
1323            let (snapshot, _) = map.read(buffer_snapshot.clone(), vec![]);
1324            assert_eq!(snapshot.text(), "⋯b⋯ijkl");
1325
1326            // Create an fold adjacent to the end of the first fold.
1327            let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1328            writer.fold(vec![11..11, 8..10]);
1329            let (snapshot, _) = map.read(buffer_snapshot.clone(), vec![]);
1330            assert_eq!(snapshot.text(), "⋯b⋯kl");
1331        }
1332
1333        {
1334            let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1335
1336            // Create two adjacent folds.
1337            let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1338            writer.fold(vec![0..2, 2..5]);
1339            let (snapshot, _) = map.read(buffer_snapshot, vec![]);
1340            assert_eq!(snapshot.text(), "⋯fghijkl");
1341
1342            // Edit within one of the folds.
1343            let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1344                buffer.edit([(0..1, "12345")], None, cx);
1345                buffer.snapshot(cx)
1346            });
1347            let (snapshot, _) = map.read(buffer_snapshot, subscription.consume().into_inner());
1348            assert_eq!(snapshot.text(), "12345⋯fghijkl");
1349        }
1350    }
1351
1352    #[gpui::test]
1353    fn test_overlapping_folds(cx: &mut gpui::AppContext) {
1354        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1355        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1356        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1357        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1358        writer.fold(vec![
1359            Point::new(0, 2)..Point::new(2, 2),
1360            Point::new(0, 4)..Point::new(1, 0),
1361            Point::new(1, 2)..Point::new(3, 2),
1362            Point::new(3, 1)..Point::new(4, 1),
1363        ]);
1364        let (snapshot, _) = map.read(buffer_snapshot, vec![]);
1365        assert_eq!(snapshot.text(), "aa⋯eeeee");
1366    }
1367
1368    #[gpui::test]
1369    fn test_merging_folds_via_edit(cx: &mut gpui::AppContext) {
1370        init_test(cx);
1371        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1372        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1373        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1374        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1375
1376        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1377        writer.fold(vec![
1378            Point::new(0, 2)..Point::new(2, 2),
1379            Point::new(3, 1)..Point::new(4, 1),
1380        ]);
1381        let (snapshot, _) = map.read(buffer_snapshot, vec![]);
1382        assert_eq!(snapshot.text(), "aa⋯cccc\nd⋯eeeee");
1383
1384        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1385            buffer.edit([(Point::new(2, 2)..Point::new(3, 1), "")], None, cx);
1386            buffer.snapshot(cx)
1387        });
1388        let (snapshot, _) = map.read(buffer_snapshot, subscription.consume().into_inner());
1389        assert_eq!(snapshot.text(), "aa⋯eeeee");
1390    }
1391
1392    #[gpui::test]
1393    fn test_folds_in_range(cx: &mut gpui::AppContext) {
1394        let buffer = MultiBuffer::build_simple(&sample_text(5, 6, 'a'), cx);
1395        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1396        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1397
1398        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1399        writer.fold(vec![
1400            Point::new(0, 2)..Point::new(2, 2),
1401            Point::new(0, 4)..Point::new(1, 0),
1402            Point::new(1, 2)..Point::new(3, 2),
1403            Point::new(3, 1)..Point::new(4, 1),
1404        ]);
1405        let (snapshot, _) = map.read(buffer_snapshot.clone(), vec![]);
1406        let fold_ranges = snapshot
1407            .folds_in_range(Point::new(1, 0)..Point::new(1, 3))
1408            .map(|fold| fold.start.to_point(&buffer_snapshot)..fold.end.to_point(&buffer_snapshot))
1409            .collect::<Vec<_>>();
1410        assert_eq!(
1411            fold_ranges,
1412            vec![
1413                Point::new(0, 2)..Point::new(2, 2),
1414                Point::new(1, 2)..Point::new(3, 2)
1415            ]
1416        );
1417    }
1418
1419    #[gpui::test(iterations = 100)]
1420    fn test_random_folds(cx: &mut gpui::AppContext, mut rng: StdRng) {
1421        init_test(cx);
1422        let operations = env::var("OPERATIONS")
1423            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1424            .unwrap_or(10);
1425
1426        let len = rng.gen_range(0..10);
1427        let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1428        let buffer = if rng.gen() {
1429            MultiBuffer::build_simple(&text, cx)
1430        } else {
1431            MultiBuffer::build_random(&mut rng, cx)
1432        };
1433        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1434        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1435
1436        let (mut initial_snapshot, _) = map.read(buffer_snapshot.clone(), vec![]);
1437        let mut snapshot_edits = Vec::new();
1438
1439        let mut highlights = TreeMap::default();
1440        let highlight_count = rng.gen_range(0_usize..10);
1441        let mut highlight_ranges = (0..highlight_count)
1442            .map(|_| buffer_snapshot.random_byte_range(0, &mut rng))
1443            .collect::<Vec<_>>();
1444        highlight_ranges.sort_by_key(|range| (range.start, Reverse(range.end)));
1445        log::info!("highlighting ranges {:?}", highlight_ranges);
1446        let highlight_ranges = highlight_ranges
1447            .into_iter()
1448            .map(|range| {
1449                buffer_snapshot.anchor_before(range.start)..buffer_snapshot.anchor_after(range.end)
1450            })
1451            .collect::<Vec<_>>();
1452
1453        highlights.insert(
1454            Some(TypeId::of::<()>()),
1455            Arc::new((HighlightStyle::default(), highlight_ranges)),
1456        );
1457
1458        for _ in 0..operations {
1459            log::info!("text: {:?}", buffer_snapshot.text());
1460            let mut buffer_edits = Vec::new();
1461            match rng.gen_range(0..=100) {
1462                0..=59 => {
1463                    snapshot_edits.extend(map.randomly_mutate(&mut rng));
1464                }
1465                _ => buffer.update(cx, |buffer, cx| {
1466                    let subscription = buffer.subscribe();
1467                    let edit_count = rng.gen_range(1..=5);
1468                    buffer.randomly_mutate(&mut rng, edit_count, cx);
1469                    buffer_snapshot = buffer.snapshot(cx);
1470                    let edits = subscription.consume().into_inner();
1471                    log::info!("editing {:?}", edits);
1472                    buffer_edits.extend(edits);
1473                }),
1474            };
1475
1476            let (snapshot, edits) = map.read(buffer_snapshot.clone(), buffer_edits);
1477            snapshot_edits.push((snapshot.clone(), edits));
1478
1479            let mut expected_text: String = buffer_snapshot.text().to_string();
1480            for fold_range in map.merged_fold_ranges().into_iter().rev() {
1481                expected_text.replace_range(fold_range.start..fold_range.end, "⋯");
1482            }
1483
1484            assert_eq!(snapshot.text(), expected_text);
1485            log::info!(
1486                "fold text {:?} ({} lines)",
1487                expected_text,
1488                expected_text.matches('\n').count() + 1
1489            );
1490
1491            let mut prev_row = 0;
1492            let mut expected_buffer_rows = Vec::new();
1493            for fold_range in map.merged_fold_ranges().into_iter() {
1494                let fold_start = buffer_snapshot.offset_to_point(fold_range.start).row;
1495                let fold_end = buffer_snapshot.offset_to_point(fold_range.end).row;
1496                expected_buffer_rows.extend(
1497                    buffer_snapshot
1498                        .buffer_rows(prev_row)
1499                        .take((1 + fold_start - prev_row) as usize),
1500                );
1501                prev_row = 1 + fold_end;
1502            }
1503            expected_buffer_rows.extend(buffer_snapshot.buffer_rows(prev_row));
1504
1505            assert_eq!(
1506                expected_buffer_rows.len(),
1507                expected_text.matches('\n').count() + 1,
1508                "wrong expected buffer rows {:?}. text: {:?}",
1509                expected_buffer_rows,
1510                expected_text
1511            );
1512
1513            for (output_row, line) in expected_text.lines().enumerate() {
1514                let line_len = snapshot.line_len(output_row as u32);
1515                assert_eq!(line_len, line.len() as u32);
1516            }
1517
1518            let longest_row = snapshot.longest_row();
1519            let longest_char_column = expected_text
1520                .split('\n')
1521                .nth(longest_row as usize)
1522                .unwrap()
1523                .chars()
1524                .count();
1525            let mut fold_point = FoldPoint::new(0, 0);
1526            let mut fold_offset = FoldOffset(0);
1527            let mut char_column = 0;
1528            for c in expected_text.chars() {
1529                let buffer_point = fold_point.to_buffer_point(&snapshot);
1530                let buffer_offset = buffer_point.to_offset(&buffer_snapshot);
1531                assert_eq!(
1532                    snapshot.to_fold_point(buffer_point, Right),
1533                    fold_point,
1534                    "{:?} -> fold point",
1535                    buffer_point,
1536                );
1537                assert_eq!(
1538                    fold_point.to_buffer_offset(&snapshot),
1539                    buffer_offset,
1540                    "fold_point.to_buffer_offset({:?})",
1541                    fold_point,
1542                );
1543                assert_eq!(
1544                    fold_point.to_offset(&snapshot),
1545                    fold_offset,
1546                    "fold_point.to_offset({:?})",
1547                    fold_point,
1548                );
1549
1550                if c == '\n' {
1551                    *fold_point.row_mut() += 1;
1552                    *fold_point.column_mut() = 0;
1553                    char_column = 0;
1554                } else {
1555                    *fold_point.column_mut() += c.len_utf8() as u32;
1556                    char_column += 1;
1557                }
1558                fold_offset.0 += c.len_utf8();
1559                if char_column > longest_char_column {
1560                    panic!(
1561                        "invalid longest row {:?} (chars {}), found row {:?} (chars: {})",
1562                        longest_row,
1563                        longest_char_column,
1564                        fold_point.row(),
1565                        char_column
1566                    );
1567                }
1568            }
1569
1570            for _ in 0..5 {
1571                let mut start = snapshot
1572                    .clip_offset(FoldOffset(rng.gen_range(0..=snapshot.len().0)), Bias::Left);
1573                let mut end = snapshot
1574                    .clip_offset(FoldOffset(rng.gen_range(0..=snapshot.len().0)), Bias::Right);
1575                if start > end {
1576                    mem::swap(&mut start, &mut end);
1577                }
1578
1579                let text = &expected_text[start.0..end.0];
1580                assert_eq!(
1581                    snapshot
1582                        .chunks(start..end, false, Some(&highlights))
1583                        .map(|c| c.text)
1584                        .collect::<String>(),
1585                    text,
1586                );
1587            }
1588
1589            let mut fold_row = 0;
1590            while fold_row < expected_buffer_rows.len() as u32 {
1591                fold_row = snapshot
1592                    .clip_point(FoldPoint::new(fold_row, 0), Bias::Right)
1593                    .row();
1594                assert_eq!(
1595                    snapshot.buffer_rows(fold_row).collect::<Vec<_>>(),
1596                    expected_buffer_rows[(fold_row as usize)..],
1597                    "wrong buffer rows starting at fold row {}",
1598                    fold_row,
1599                );
1600                fold_row += 1;
1601            }
1602
1603            let fold_start_rows = map
1604                .merged_fold_ranges()
1605                .iter()
1606                .map(|range| range.start.to_point(&buffer_snapshot).row)
1607                .collect::<HashSet<_>>();
1608            for row in fold_start_rows {
1609                assert!(snapshot.is_line_folded(row));
1610            }
1611
1612            for _ in 0..5 {
1613                let end =
1614                    buffer_snapshot.clip_offset(rng.gen_range(0..=buffer_snapshot.len()), Right);
1615                let start = buffer_snapshot.clip_offset(rng.gen_range(0..=end), Left);
1616                let expected_folds = map
1617                    .folds
1618                    .items(&buffer_snapshot)
1619                    .into_iter()
1620                    .filter(|fold| {
1621                        let start = buffer_snapshot.anchor_before(start);
1622                        let end = buffer_snapshot.anchor_after(end);
1623                        start.cmp(&fold.0.end, &buffer_snapshot) == Ordering::Less
1624                            && end.cmp(&fold.0.start, &buffer_snapshot) == Ordering::Greater
1625                    })
1626                    .map(|fold| fold.0)
1627                    .collect::<Vec<_>>();
1628
1629                assert_eq!(
1630                    snapshot
1631                        .folds_in_range(start..end)
1632                        .cloned()
1633                        .collect::<Vec<_>>(),
1634                    expected_folds
1635                );
1636            }
1637
1638            let text = snapshot.text();
1639            for _ in 0..5 {
1640                let start_row = rng.gen_range(0..=snapshot.max_point().row());
1641                let start_column = rng.gen_range(0..=snapshot.line_len(start_row));
1642                let end_row = rng.gen_range(0..=snapshot.max_point().row());
1643                let end_column = rng.gen_range(0..=snapshot.line_len(end_row));
1644                let mut start =
1645                    snapshot.clip_point(FoldPoint::new(start_row, start_column), Bias::Left);
1646                let mut end = snapshot.clip_point(FoldPoint::new(end_row, end_column), Bias::Right);
1647                if start > end {
1648                    mem::swap(&mut start, &mut end);
1649                }
1650
1651                let lines = start..end;
1652                let bytes = start.to_offset(&snapshot)..end.to_offset(&snapshot);
1653                assert_eq!(
1654                    snapshot.text_summary_for_range(lines),
1655                    TextSummary::from(&text[bytes.start.0..bytes.end.0])
1656                )
1657            }
1658
1659            let mut text = initial_snapshot.text();
1660            for (snapshot, edits) in snapshot_edits.drain(..) {
1661                let new_text = snapshot.text();
1662                for edit in edits {
1663                    let old_bytes = edit.new.start.0..edit.new.start.0 + edit.old_len().0;
1664                    let new_bytes = edit.new.start.0..edit.new.end.0;
1665                    text.replace_range(old_bytes, &new_text[new_bytes]);
1666                }
1667
1668                assert_eq!(text, new_text);
1669                initial_snapshot = snapshot;
1670            }
1671        }
1672    }
1673
1674    #[gpui::test]
1675    fn test_buffer_rows(cx: &mut gpui::AppContext) {
1676        let text = sample_text(6, 6, 'a') + "\n";
1677        let buffer = MultiBuffer::build_simple(&text, cx);
1678
1679        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1680        let mut map = FoldMap::new(buffer_snapshot.clone()).0;
1681
1682        let (mut writer, _, _) = map.write(buffer_snapshot.clone(), vec![]);
1683        writer.fold(vec![
1684            Point::new(0, 2)..Point::new(2, 2),
1685            Point::new(3, 1)..Point::new(4, 1),
1686        ]);
1687
1688        let (snapshot, _) = map.read(buffer_snapshot, vec![]);
1689        assert_eq!(snapshot.text(), "aa⋯cccc\nd⋯eeeee\nffffff\n");
1690        assert_eq!(
1691            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1692            [Some(0), Some(3), Some(5), Some(6)]
1693        );
1694        assert_eq!(snapshot.buffer_rows(3).collect::<Vec<_>>(), [Some(6)]);
1695    }
1696
1697    fn init_test(cx: &mut gpui::AppContext) {
1698        cx.set_global(SettingsStore::test(cx));
1699    }
1700
1701    impl FoldMap {
1702        fn merged_fold_ranges(&self) -> Vec<Range<usize>> {
1703            let buffer = self.buffer.lock().clone();
1704            let mut folds = self.folds.items(&buffer);
1705            // Ensure sorting doesn't change how folds get merged and displayed.
1706            folds.sort_by(|a, b| a.0.cmp(&b.0, &buffer));
1707            let mut fold_ranges = folds
1708                .iter()
1709                .map(|fold| fold.0.start.to_offset(&buffer)..fold.0.end.to_offset(&buffer))
1710                .peekable();
1711
1712            let mut merged_ranges = Vec::new();
1713            while let Some(mut fold_range) = fold_ranges.next() {
1714                while let Some(next_range) = fold_ranges.peek() {
1715                    if fold_range.end >= next_range.start {
1716                        if next_range.end > fold_range.end {
1717                            fold_range.end = next_range.end;
1718                        }
1719                        fold_ranges.next();
1720                    } else {
1721                        break;
1722                    }
1723                }
1724                if fold_range.end > fold_range.start {
1725                    merged_ranges.push(fold_range);
1726                }
1727            }
1728            merged_ranges
1729        }
1730
1731        pub fn randomly_mutate(
1732            &mut self,
1733            rng: &mut impl Rng,
1734        ) -> Vec<(FoldSnapshot, Vec<FoldEdit>)> {
1735            let mut snapshot_edits = Vec::new();
1736            match rng.gen_range(0..=100) {
1737                0..=39 if !self.folds.is_empty() => {
1738                    let buffer = self.buffer.lock().clone();
1739                    let mut to_unfold = Vec::new();
1740                    for _ in 0..rng.gen_range(1..=3) {
1741                        let end = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Right);
1742                        let start = buffer.clip_offset(rng.gen_range(0..=end), Left);
1743                        to_unfold.push(start..end);
1744                    }
1745                    log::info!("unfolding {:?}", to_unfold);
1746                    let (mut writer, snapshot, edits) = self.write(buffer, vec![]);
1747                    snapshot_edits.push((snapshot, edits));
1748                    let (snapshot, edits) = writer.fold(to_unfold);
1749                    snapshot_edits.push((snapshot, edits));
1750                }
1751                _ => {
1752                    let buffer = self.buffer.lock().clone();
1753                    let mut to_fold = Vec::new();
1754                    for _ in 0..rng.gen_range(1..=2) {
1755                        let end = buffer.clip_offset(rng.gen_range(0..=buffer.len()), Right);
1756                        let start = buffer.clip_offset(rng.gen_range(0..=end), Left);
1757                        to_fold.push(start..end);
1758                    }
1759                    log::info!("folding {:?}", to_fold);
1760                    let (mut writer, snapshot, edits) = self.write(buffer, vec![]);
1761                    snapshot_edits.push((snapshot, edits));
1762                    let (snapshot, edits) = writer.fold(to_fold);
1763                    snapshot_edits.push((snapshot, edits));
1764                }
1765            }
1766            snapshot_edits
1767        }
1768    }
1769}