block_map.rs

   1use super::wrap_map::{self, Edit as WrapEdit, Snapshot as WrapSnapshot, WrapPoint};
   2use buffer::{rope, Anchor, Bias, Edit, Point, Rope, ToOffset, ToPoint as _};
   3use gpui::{fonts::HighlightStyle, AppContext, ModelHandle};
   4use language::{Buffer, Chunk};
   5use parking_lot::Mutex;
   6use std::{
   7    cmp::{self, Ordering},
   8    collections::HashSet,
   9    iter,
  10    ops::Range,
  11    slice,
  12    sync::{
  13        atomic::{AtomicUsize, Ordering::SeqCst},
  14        Arc,
  15    },
  16};
  17use sum_tree::SumTree;
  18
  19pub struct BlockMap {
  20    buffer: ModelHandle<Buffer>,
  21    next_block_id: AtomicUsize,
  22    wrap_snapshot: Mutex<WrapSnapshot>,
  23    blocks: Vec<Arc<Block>>,
  24    transforms: Mutex<SumTree<Transform>>,
  25}
  26
  27pub struct BlockMapWriter<'a>(&'a mut BlockMap);
  28
  29pub struct BlockSnapshot {
  30    wrap_snapshot: WrapSnapshot,
  31    transforms: SumTree<Transform>,
  32}
  33
  34#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
  35pub struct BlockId(usize);
  36
  37#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  38pub struct BlockPoint(pub super::Point);
  39
  40#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  41struct BlockRow(u32);
  42
  43#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  44struct WrapRow(u32);
  45
  46#[derive(Debug)]
  47struct Block {
  48    id: BlockId,
  49    position: Anchor,
  50    text: Rope,
  51    runs: Vec<(usize, HighlightStyle)>,
  52    disposition: BlockDisposition,
  53}
  54
  55#[derive(Clone)]
  56pub struct BlockProperties<P, T>
  57where
  58    P: Clone,
  59    T: Clone,
  60{
  61    pub position: P,
  62    pub text: T,
  63    pub runs: Vec<(usize, HighlightStyle)>,
  64    pub disposition: BlockDisposition,
  65}
  66
  67#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  68pub enum BlockDisposition {
  69    Above,
  70    Below,
  71}
  72
  73#[derive(Clone, Debug)]
  74struct Transform {
  75    summary: TransformSummary,
  76    block: Option<Arc<Block>>,
  77}
  78
  79#[derive(Clone, Debug, Default)]
  80struct TransformSummary {
  81    input_rows: u32,
  82    output_rows: u32,
  83    longest_row_in_block: u32,
  84    longest_row_in_block_chars: u32,
  85}
  86
  87pub struct Chunks<'a> {
  88    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
  89    input_chunks: wrap_map::Chunks<'a>,
  90    input_chunk: Chunk<'a>,
  91    block_chunks: Option<BlockChunks<'a>>,
  92    output_row: u32,
  93    max_output_row: u32,
  94}
  95
  96struct BlockChunks<'a> {
  97    chunks: rope::Chunks<'a>,
  98    runs: iter::Peekable<slice::Iter<'a, (usize, HighlightStyle)>>,
  99    chunk: Option<&'a str>,
 100    run_start: usize,
 101    offset: usize,
 102}
 103
 104pub struct BufferRows<'a> {
 105    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 106    input_buffer_rows: wrap_map::BufferRows<'a>,
 107    output_row: u32,
 108    started: bool,
 109}
 110
 111impl BlockMap {
 112    pub fn new(buffer: ModelHandle<Buffer>, wrap_snapshot: WrapSnapshot) -> Self {
 113        Self {
 114            buffer,
 115            next_block_id: AtomicUsize::new(0),
 116            blocks: Vec::new(),
 117            transforms: Mutex::new(SumTree::from_item(
 118                Transform::isomorphic(wrap_snapshot.text_summary().lines.row + 1),
 119                &(),
 120            )),
 121            wrap_snapshot: Mutex::new(wrap_snapshot),
 122        }
 123    }
 124
 125    pub fn read(
 126        &self,
 127        wrap_snapshot: WrapSnapshot,
 128        edits: Vec<WrapEdit>,
 129        cx: &AppContext,
 130    ) -> BlockSnapshot {
 131        self.sync(&wrap_snapshot, edits, cx);
 132        *self.wrap_snapshot.lock() = wrap_snapshot.clone();
 133        BlockSnapshot {
 134            wrap_snapshot,
 135            transforms: self.transforms.lock().clone(),
 136        }
 137    }
 138
 139    pub fn write(
 140        &mut self,
 141        wrap_snapshot: WrapSnapshot,
 142        edits: Vec<WrapEdit>,
 143        cx: &AppContext,
 144    ) -> BlockMapWriter {
 145        self.sync(&wrap_snapshot, edits, cx);
 146        *self.wrap_snapshot.lock() = wrap_snapshot;
 147        BlockMapWriter(self)
 148    }
 149
 150    pub fn sync(&self, wrap_snapshot: &WrapSnapshot, edits: Vec<WrapEdit>, cx: &AppContext) {
 151        if edits.is_empty() {
 152            return;
 153        }
 154
 155        let buffer = self.buffer.read(cx);
 156        let mut transforms = self.transforms.lock();
 157        let mut new_transforms = SumTree::new();
 158        let old_row_count = transforms.summary().input_rows;
 159        let new_row_count = wrap_snapshot.max_point().row() + 1;
 160        let mut cursor = transforms.cursor::<WrapRow>();
 161        let mut last_block_ix = 0;
 162        let mut blocks_in_edit = Vec::new();
 163        let mut edits = edits.into_iter().peekable();
 164
 165        while let Some(edit) = edits.next() {
 166            // Preserve any old transforms that precede this edit.
 167            let old_start = WrapRow(edit.old.start);
 168            let new_start = WrapRow(edit.new.start);
 169            new_transforms.push_tree(cursor.slice(&old_start, Bias::Left, &()), &());
 170            if let Some(transform) = cursor.item() {
 171                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 172                    new_transforms.push(transform.clone(), &());
 173                    cursor.next(&());
 174                    while let Some(transform) = cursor.item() {
 175                        if transform
 176                            .block
 177                            .as_ref()
 178                            .map_or(false, |b| b.disposition.is_below())
 179                        {
 180                            new_transforms.push(transform.clone(), &());
 181                            cursor.next(&());
 182                        } else {
 183                            break;
 184                        }
 185                    }
 186                }
 187            }
 188
 189            // Preserve any portion of an old transform that precedes this edit.
 190            let extent_before_edit = old_start.0 - cursor.start().0;
 191            push_isomorphic(&mut new_transforms, extent_before_edit);
 192
 193            // Skip over any old transforms that intersect this edit.
 194            let mut old_end = WrapRow(edit.old.end);
 195            let mut new_end = WrapRow(edit.new.end);
 196            cursor.seek(&old_end, Bias::Left, &());
 197            cursor.next(&());
 198            if old_end == *cursor.start() {
 199                while let Some(transform) = cursor.item() {
 200                    if transform
 201                        .block
 202                        .as_ref()
 203                        .map_or(false, |b| b.disposition.is_below())
 204                    {
 205                        cursor.next(&());
 206                    } else {
 207                        break;
 208                    }
 209                }
 210            }
 211
 212            // Combine this edit with any subsequent edits that intersect the same transform.
 213            while let Some(next_edit) = edits.peek() {
 214                if next_edit.old.start <= cursor.start().0 {
 215                    old_end = WrapRow(next_edit.old.end);
 216                    new_end = WrapRow(next_edit.new.end);
 217                    cursor.seek(&old_end, Bias::Left, &());
 218                    cursor.next(&());
 219                    if old_end == *cursor.start() {
 220                        while let Some(transform) = cursor.item() {
 221                            if transform
 222                                .block
 223                                .as_ref()
 224                                .map_or(false, |b| b.disposition.is_below())
 225                            {
 226                                cursor.next(&());
 227                            } else {
 228                                break;
 229                            }
 230                        }
 231                    }
 232                    edits.next();
 233                } else {
 234                    break;
 235                }
 236            }
 237
 238            // Find the blocks within this edited region.
 239            let new_start = wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 240            let start_anchor = buffer.anchor_before(new_start);
 241            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 242                probe
 243                    .position
 244                    .cmp(&start_anchor, buffer)
 245                    .unwrap()
 246                    .then(Ordering::Greater)
 247            }) {
 248                Ok(ix) | Err(ix) => last_block_ix + ix,
 249            };
 250            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 251                self.blocks.len()
 252            } else {
 253                let new_end = wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 254                let end_anchor = buffer.anchor_before(new_end);
 255                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 256                    probe
 257                        .position
 258                        .cmp(&end_anchor, buffer)
 259                        .unwrap()
 260                        .then(Ordering::Greater)
 261                }) {
 262                    Ok(ix) | Err(ix) => start_block_ix + ix,
 263                }
 264            };
 265            last_block_ix = end_block_ix;
 266            blocks_in_edit.clear();
 267            blocks_in_edit.extend(
 268                self.blocks[start_block_ix..end_block_ix]
 269                    .iter()
 270                    .map(|block| {
 271                        let mut position = block.position.to_point(buffer);
 272                        match block.disposition {
 273                            BlockDisposition::Above => position.column = 0,
 274                            BlockDisposition::Below => {
 275                                position.column = buffer.line_len(position.row)
 276                            }
 277                        }
 278                        let position = wrap_snapshot.from_point(position, Bias::Left);
 279                        (position.row(), block)
 280                    }),
 281            );
 282            blocks_in_edit.sort_unstable_by_key(|(row, block)| (*row, block.disposition, block.id));
 283
 284            // For each of these blocks, insert a new isomorphic transform preceding the block,
 285            // and then insert the block itself.
 286            for (block_row, block) in blocks_in_edit.iter().copied() {
 287                let insertion_row = match block.disposition {
 288                    BlockDisposition::Above => block_row,
 289                    BlockDisposition::Below => block_row + 1,
 290                };
 291                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 292                push_isomorphic(&mut new_transforms, extent_before_block);
 293                new_transforms.push(Transform::block(block.clone()), &());
 294            }
 295
 296            old_end = WrapRow(old_end.0.min(old_row_count));
 297            new_end = WrapRow(new_end.0.min(new_row_count));
 298
 299            // Insert an isomorphic transform after the final block.
 300            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 301            push_isomorphic(&mut new_transforms, extent_after_last_block);
 302
 303            // Preserve any portion of the old transform after this edit.
 304            let extent_after_edit = cursor.start().0 - old_end.0;
 305            push_isomorphic(&mut new_transforms, extent_after_edit);
 306        }
 307
 308        new_transforms.push_tree(cursor.suffix(&()), &());
 309        debug_assert_eq!(
 310            new_transforms.summary().input_rows,
 311            wrap_snapshot.max_point().row() + 1
 312        );
 313
 314        drop(cursor);
 315        *transforms = new_transforms;
 316    }
 317}
 318
 319fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 320    if rows == 0 {
 321        return;
 322    }
 323
 324    let mut extent = Some(rows);
 325    tree.update_last(
 326        |last_transform| {
 327            if last_transform.is_isomorphic() {
 328                let extent = extent.take().unwrap();
 329                last_transform.summary.input_rows += extent;
 330                last_transform.summary.output_rows += extent;
 331            }
 332        },
 333        &(),
 334    );
 335    if let Some(extent) = extent {
 336        tree.push(Transform::isomorphic(extent), &());
 337    }
 338}
 339
 340impl BlockPoint {
 341    pub fn new(row: u32, column: u32) -> Self {
 342        Self(Point::new(row, column))
 343    }
 344}
 345
 346impl std::ops::Deref for BlockPoint {
 347    type Target = Point;
 348
 349    fn deref(&self) -> &Self::Target {
 350        &self.0
 351    }
 352}
 353
 354impl std::ops::DerefMut for BlockPoint {
 355    fn deref_mut(&mut self) -> &mut Self::Target {
 356        &mut self.0
 357    }
 358}
 359
 360impl<'a> BlockMapWriter<'a> {
 361    pub fn insert<P, T>(
 362        &mut self,
 363        blocks: impl IntoIterator<Item = BlockProperties<P, T>>,
 364        cx: &AppContext,
 365    ) -> Vec<BlockId>
 366    where
 367        P: ToOffset + Clone,
 368        T: Into<Rope> + Clone,
 369    {
 370        let buffer = self.0.buffer.read(cx);
 371        let mut ids = Vec::new();
 372        let mut edits = Vec::<Edit<u32>>::new();
 373        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 374
 375        for block in blocks {
 376            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 377            ids.push(id);
 378
 379            let position = buffer.anchor_before(block.position);
 380            let point = position.to_point(buffer);
 381            let start_row = wrap_snapshot
 382                .from_point(Point::new(point.row, 0), Bias::Left)
 383                .row();
 384            let end_row = if point.row == buffer.max_point().row {
 385                wrap_snapshot.max_point().row() + 1
 386            } else {
 387                wrap_snapshot
 388                    .from_point(Point::new(point.row + 1, 0), Bias::Left)
 389                    .row()
 390            };
 391
 392            let block_ix = match self
 393                .0
 394                .blocks
 395                .binary_search_by(|probe| probe.position.cmp(&position, buffer).unwrap())
 396            {
 397                Ok(ix) | Err(ix) => ix,
 398            };
 399            self.0.blocks.insert(
 400                block_ix,
 401                Arc::new(Block {
 402                    id,
 403                    position,
 404                    text: block.text.into(),
 405                    runs: block.runs,
 406                    disposition: block.disposition,
 407                }),
 408            );
 409
 410            if let Err(edit_ix) = edits.binary_search_by_key(&start_row, |edit| edit.old.start) {
 411                edits.insert(
 412                    edit_ix,
 413                    Edit {
 414                        old: start_row..end_row,
 415                        new: start_row..end_row,
 416                    },
 417                );
 418            }
 419        }
 420
 421        self.0.sync(wrap_snapshot, edits, cx);
 422        ids
 423    }
 424
 425    pub fn remove(&mut self, block_ids: HashSet<BlockId>, cx: &AppContext) {
 426        let buffer = self.0.buffer.read(cx);
 427        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 428        let mut edits = Vec::new();
 429        let mut last_block_buffer_row = None;
 430        self.0.blocks.retain(|block| {
 431            if block_ids.contains(&block.id) {
 432                let buffer_row = block.position.to_point(buffer).row;
 433                if last_block_buffer_row != Some(buffer_row) {
 434                    last_block_buffer_row = Some(buffer_row);
 435                    let start_row = wrap_snapshot
 436                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 437                        .row();
 438                    let end_row = wrap_snapshot
 439                        .from_point(
 440                            Point::new(buffer_row, buffer.line_len(buffer_row)),
 441                            Bias::Left,
 442                        )
 443                        .row()
 444                        + 1;
 445                    edits.push(Edit {
 446                        old: start_row..end_row,
 447                        new: start_row..end_row,
 448                    })
 449                }
 450                false
 451            } else {
 452                true
 453            }
 454        });
 455        self.0.sync(wrap_snapshot, edits, cx);
 456    }
 457}
 458
 459impl BlockSnapshot {
 460    #[cfg(test)]
 461    fn text(&mut self) -> String {
 462        self.chunks(0..self.transforms.summary().output_rows, false)
 463            .map(|chunk| chunk.text)
 464            .collect()
 465    }
 466
 467    pub fn chunks(&self, rows: Range<u32>, highlights: bool) -> Chunks {
 468        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 469        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 470        let input_end = {
 471            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 472            let overshoot = if cursor
 473                .item()
 474                .map_or(false, |transform| transform.is_isomorphic())
 475            {
 476                rows.end - cursor.start().0 .0
 477            } else {
 478                0
 479            };
 480            cursor.start().1 .0 + overshoot
 481        };
 482        let input_start = {
 483            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 484            let overshoot = if cursor
 485                .item()
 486                .map_or(false, |transform| transform.is_isomorphic())
 487            {
 488                rows.start - cursor.start().0 .0
 489            } else {
 490                0
 491            };
 492            cursor.start().1 .0 + overshoot
 493        };
 494        Chunks {
 495            input_chunks: self
 496                .wrap_snapshot
 497                .chunks(input_start..input_end, highlights),
 498            input_chunk: Default::default(),
 499            block_chunks: None,
 500            transforms: cursor,
 501            output_row: rows.start,
 502            max_output_row,
 503        }
 504    }
 505
 506    pub fn buffer_rows(&self, start_row: u32) -> BufferRows {
 507        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 508        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 509        let (input_start, output_start) = cursor.start();
 510        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 511            start_row - output_start.0
 512        } else {
 513            0
 514        };
 515        let input_start_row = input_start.0 + overshoot;
 516        BufferRows {
 517            transforms: cursor,
 518            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 519            output_row: start_row,
 520            started: false,
 521        }
 522    }
 523
 524    pub fn max_point(&self) -> BlockPoint {
 525        let row = self.transforms.summary().output_rows - 1;
 526        BlockPoint::new(row, self.line_len(row))
 527    }
 528
 529    pub fn longest_row(&self) -> u32 {
 530        let input_row = self.wrap_snapshot.longest_row();
 531        let input_row_chars = self.wrap_snapshot.line_char_count(input_row);
 532        let TransformSummary {
 533            longest_row_in_block: block_row,
 534            longest_row_in_block_chars: block_row_chars,
 535            ..
 536        } = &self.transforms.summary();
 537
 538        if *block_row_chars > input_row_chars {
 539            *block_row
 540        } else {
 541            self.to_block_point(WrapPoint::new(input_row, 0)).row
 542        }
 543    }
 544
 545    pub fn line_len(&self, row: u32) -> u32 {
 546        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 547        cursor.seek(&BlockRow(row), Bias::Right, &());
 548        if let Some(transform) = cursor.item() {
 549            let (output_start, input_start) = cursor.start();
 550            let overshoot = row - output_start.0;
 551            if let Some(block) = &transform.block {
 552                block.text.line_len(overshoot)
 553            } else {
 554                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 555            }
 556        } else {
 557            panic!("row out of range");
 558        }
 559    }
 560
 561    pub fn is_block_line(&self, row: u32) -> bool {
 562        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 563        cursor.seek(&BlockRow(row), Bias::Right, &());
 564        cursor.item().map_or(false, |t| t.block.is_some())
 565    }
 566
 567    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 568        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 569        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 570
 571        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 572        let search_left =
 573            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 574
 575        loop {
 576            if let Some(transform) = cursor.item() {
 577                if transform.is_isomorphic() {
 578                    let (output_start_row, input_start_row) = cursor.start();
 579                    let (output_end_row, input_end_row) = cursor.end(&());
 580
 581                    if point.row >= output_end_row.0 {
 582                        return BlockPoint::new(
 583                            output_end_row.0 - 1,
 584                            self.wrap_snapshot.line_len(input_end_row.0 - 1),
 585                        );
 586                    }
 587
 588                    let output_start = Point::new(output_start_row.0, 0);
 589                    if point.0 > output_start {
 590                        let output_overshoot = point.0 - output_start;
 591                        let input_start = Point::new(input_start_row.0, 0);
 592                        let input_point = self
 593                            .wrap_snapshot
 594                            .clip_point(WrapPoint(input_start + output_overshoot), bias);
 595                        let input_overshoot = input_point.0 - input_start;
 596                        return BlockPoint(output_start + input_overshoot);
 597                    } else {
 598                        return BlockPoint(output_start);
 599                    }
 600                } else if search_left {
 601                    cursor.prev(&());
 602                } else {
 603                    cursor.next(&());
 604                }
 605            } else {
 606                return self.max_point();
 607            }
 608        }
 609    }
 610
 611    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 612        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 613        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 614        if let Some(transform) = cursor.item() {
 615            debug_assert!(transform.is_isomorphic());
 616        } else {
 617            return self.max_point();
 618        }
 619
 620        let (input_start_row, output_start_row) = cursor.start();
 621        let input_start = Point::new(input_start_row.0, 0);
 622        let output_start = Point::new(output_start_row.0, 0);
 623        let input_overshoot = wrap_point.0 - input_start;
 624        BlockPoint(output_start + input_overshoot)
 625    }
 626
 627    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 628        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 629        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 630        if let Some(transform) = cursor.item() {
 631            match transform.block.as_ref().map(|b| b.disposition) {
 632                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 633                Some(BlockDisposition::Below) => {
 634                    let wrap_row = cursor.start().1 .0 - 1;
 635                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 636                }
 637                None => {
 638                    let overshoot = block_point.row - cursor.start().0 .0;
 639                    let wrap_row = cursor.start().1 .0 + overshoot;
 640                    WrapPoint::new(wrap_row, block_point.column)
 641                }
 642            }
 643        } else {
 644            self.wrap_snapshot.max_point()
 645        }
 646    }
 647}
 648
 649impl Transform {
 650    fn isomorphic(rows: u32) -> Self {
 651        Self {
 652            summary: TransformSummary {
 653                input_rows: rows,
 654                output_rows: rows,
 655                longest_row_in_block: 0,
 656                longest_row_in_block_chars: 0,
 657            },
 658            block: None,
 659        }
 660    }
 661
 662    fn block(block: Arc<Block>) -> Self {
 663        let text_summary = block.text.summary();
 664        Self {
 665            summary: TransformSummary {
 666                input_rows: 0,
 667                output_rows: text_summary.lines.row + 1,
 668                longest_row_in_block: text_summary.longest_row,
 669                longest_row_in_block_chars: text_summary.longest_row_chars,
 670            },
 671            block: Some(block),
 672        }
 673    }
 674
 675    fn is_isomorphic(&self) -> bool {
 676        self.block.is_none()
 677    }
 678}
 679
 680impl<'a> Iterator for Chunks<'a> {
 681    type Item = Chunk<'a>;
 682
 683    fn next(&mut self) -> Option<Self::Item> {
 684        if self.output_row >= self.max_output_row {
 685            return None;
 686        }
 687
 688        if let Some(block_chunks) = self.block_chunks.as_mut() {
 689            if let Some(block_chunk) = block_chunks.next() {
 690                self.output_row += block_chunk.text.matches('\n').count() as u32;
 691                return Some(block_chunk);
 692            } else {
 693                self.block_chunks.take();
 694                self.output_row += 1;
 695                if self.output_row < self.max_output_row {
 696                    return Some(Chunk {
 697                        text: "\n",
 698                        ..Default::default()
 699                    });
 700                } else {
 701                    return None;
 702                }
 703            }
 704        }
 705
 706        let transform = self.transforms.item()?;
 707        if let Some(block) = transform.block.as_ref() {
 708            let block_start = self.transforms.start().0 .0;
 709            let block_end = self.transforms.end(&()).0 .0;
 710            let start_in_block = self.output_row - block_start;
 711            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 712            self.transforms.next(&());
 713            self.block_chunks = Some(BlockChunks::new(block, start_in_block..end_in_block));
 714            return self.next();
 715        }
 716
 717        if self.input_chunk.text.is_empty() {
 718            if let Some(input_chunk) = self.input_chunks.next() {
 719                self.input_chunk = input_chunk;
 720            } else {
 721                self.output_row += 1;
 722                if self.output_row < self.max_output_row {
 723                    self.transforms.next(&());
 724                    return Some(Chunk {
 725                        text: "\n",
 726                        ..Default::default()
 727                    });
 728                } else {
 729                    return None;
 730                }
 731            }
 732        }
 733
 734        let transform_end = self.transforms.end(&()).0 .0;
 735        let (prefix_rows, prefix_bytes) =
 736            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 737        self.output_row += prefix_rows;
 738        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 739        self.input_chunk.text = suffix;
 740        if self.output_row == transform_end {
 741            self.transforms.next(&());
 742        }
 743
 744        Some(Chunk {
 745            text: prefix,
 746            ..self.input_chunk
 747        })
 748    }
 749}
 750
 751impl<'a> BlockChunks<'a> {
 752    fn new(block: &'a Block, rows: Range<u32>) -> Self {
 753        let offset_range = block.text.point_to_offset(Point::new(rows.start, 0))
 754            ..block.text.point_to_offset(Point::new(rows.end, 0));
 755
 756        let mut runs = block.runs.iter().peekable();
 757        let mut run_start = 0;
 758        while let Some((run_len, _)) = runs.peek() {
 759            let run_end = run_start + run_len;
 760            if run_end <= offset_range.start {
 761                run_start = run_end;
 762                runs.next();
 763            } else {
 764                break;
 765            }
 766        }
 767
 768        Self {
 769            chunk: None,
 770            run_start,
 771            chunks: block.text.chunks_in_range(offset_range.clone()),
 772            runs,
 773            offset: offset_range.start,
 774        }
 775    }
 776}
 777
 778impl<'a> Iterator for BlockChunks<'a> {
 779    type Item = Chunk<'a>;
 780
 781    fn next(&mut self) -> Option<Self::Item> {
 782        if self.chunk.is_none() {
 783            self.chunk = self.chunks.next();
 784        }
 785
 786        let chunk = self.chunk?;
 787        let mut chunk_len = chunk.len();
 788        // let mut highlight_style = None;
 789        if let Some((run_len, _)) = self.runs.peek() {
 790            // highlight_style = Some(style.clone());
 791            let run_end_in_chunk = self.run_start + run_len - self.offset;
 792            if run_end_in_chunk <= chunk_len {
 793                chunk_len = run_end_in_chunk;
 794                self.run_start += run_len;
 795                self.runs.next();
 796            }
 797        }
 798
 799        self.offset += chunk_len;
 800        let (chunk, suffix) = chunk.split_at(chunk_len);
 801        self.chunk = if suffix.is_empty() {
 802            None
 803        } else {
 804            Some(suffix)
 805        };
 806
 807        Some(Chunk {
 808            text: chunk,
 809            highlight_id: Default::default(),
 810            diagnostic: None,
 811        })
 812    }
 813}
 814
 815impl<'a> Iterator for BufferRows<'a> {
 816    type Item = Option<u32>;
 817
 818    fn next(&mut self) -> Option<Self::Item> {
 819        if self.started {
 820            self.output_row += 1;
 821        } else {
 822            self.started = true;
 823        }
 824
 825        if self.output_row >= self.transforms.end(&()).0 .0 {
 826            self.transforms.next(&());
 827        }
 828
 829        let transform = self.transforms.item()?;
 830        if transform.is_isomorphic() {
 831            Some(self.input_buffer_rows.next().unwrap())
 832        } else {
 833            Some(None)
 834        }
 835    }
 836}
 837
 838impl sum_tree::Item for Transform {
 839    type Summary = TransformSummary;
 840
 841    fn summary(&self) -> Self::Summary {
 842        self.summary.clone()
 843    }
 844}
 845
 846impl sum_tree::Summary for TransformSummary {
 847    type Context = ();
 848
 849    fn add_summary(&mut self, summary: &Self, _: &()) {
 850        if summary.longest_row_in_block_chars > self.longest_row_in_block_chars {
 851            self.longest_row_in_block_chars = summary.longest_row_in_block_chars;
 852            self.longest_row_in_block = self.output_rows + summary.longest_row_in_block;
 853        }
 854
 855        self.input_rows += summary.input_rows;
 856        self.output_rows += summary.output_rows;
 857    }
 858}
 859
 860impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 861    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 862        self.0 += summary.input_rows;
 863    }
 864}
 865
 866impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 867    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 868        self.0 += summary.output_rows;
 869    }
 870}
 871
 872impl BlockDisposition {
 873    fn is_below(&self) -> bool {
 874        matches!(self, BlockDisposition::Below)
 875    }
 876}
 877
 878// Count the number of bytes prior to a target point. If the string doesn't contain the target
 879// point, return its total extent. Otherwise return the target point itself.
 880fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 881    let mut row = 0;
 882    let mut offset = 0;
 883    for (ix, line) in s.split('\n').enumerate() {
 884        if ix > 0 {
 885            row += 1;
 886            offset += 1;
 887        }
 888        if row >= target {
 889            break;
 890        }
 891        offset += line.len() as usize;
 892    }
 893    (row, offset)
 894}
 895
 896#[cfg(test)]
 897mod tests {
 898    use super::*;
 899    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 900    use buffer::RandomCharIter;
 901    use language::Buffer;
 902    use rand::prelude::*;
 903    use std::env;
 904
 905    #[gpui::test]
 906    fn test_offset_for_row() {
 907        assert_eq!(offset_for_row("", 0), (0, 0));
 908        assert_eq!(offset_for_row("", 1), (0, 0));
 909        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 910        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 911        assert_eq!(offset_for_row("\n", 0), (0, 0));
 912        assert_eq!(offset_for_row("\n", 1), (1, 1));
 913        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 914        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 915        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 916        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 917    }
 918
 919    #[gpui::test]
 920    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 921        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 922        let font_id = cx
 923            .font_cache()
 924            .select_font(family_id, &Default::default())
 925            .unwrap();
 926
 927        let text = "aaa\nbbb\nccc\nddd";
 928
 929        let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
 930        let (fold_map, folds_snapshot) = FoldMap::new(buffer.clone(), cx);
 931        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 932        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 933        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot.clone());
 934
 935        let mut writer = block_map.write(wraps_snapshot.clone(), vec![], cx);
 936        writer.insert(
 937            vec![
 938                BlockProperties {
 939                    position: Point::new(1, 0),
 940                    text: "BLOCK 1",
 941                    disposition: BlockDisposition::Above,
 942                    runs: vec![],
 943                },
 944                BlockProperties {
 945                    position: Point::new(1, 2),
 946                    text: "BLOCK 2",
 947                    disposition: BlockDisposition::Above,
 948                    runs: vec![],
 949                },
 950                BlockProperties {
 951                    position: Point::new(3, 2),
 952                    text: "BLOCK 3",
 953                    disposition: BlockDisposition::Below,
 954                    runs: vec![],
 955                },
 956            ],
 957            cx,
 958        );
 959
 960        let mut snapshot = block_map.read(wraps_snapshot, vec![], cx);
 961        assert_eq!(
 962            snapshot.text(),
 963            "aaa\nBLOCK 1\nBLOCK 2\nbbb\nccc\nddd\nBLOCK 3"
 964        );
 965        assert_eq!(
 966            snapshot.to_block_point(WrapPoint::new(0, 3)),
 967            BlockPoint::new(0, 3)
 968        );
 969        assert_eq!(
 970            snapshot.to_block_point(WrapPoint::new(1, 0)),
 971            BlockPoint::new(3, 0)
 972        );
 973        assert_eq!(
 974            snapshot.to_block_point(WrapPoint::new(3, 3)),
 975            BlockPoint::new(5, 3)
 976        );
 977
 978        assert_eq!(
 979            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
 980            WrapPoint::new(0, 3)
 981        );
 982        assert_eq!(
 983            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
 984            WrapPoint::new(1, 0)
 985        );
 986        assert_eq!(
 987            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
 988            WrapPoint::new(1, 0)
 989        );
 990        assert_eq!(
 991            snapshot.to_wrap_point(BlockPoint::new(6, 0)),
 992            WrapPoint::new(3, 3)
 993        );
 994
 995        assert_eq!(
 996            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
 997            BlockPoint::new(0, 3)
 998        );
 999        assert_eq!(
1000            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1001            BlockPoint::new(3, 0)
1002        );
1003        assert_eq!(
1004            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1005            BlockPoint::new(0, 3)
1006        );
1007        assert_eq!(
1008            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1009            BlockPoint::new(3, 0)
1010        );
1011        assert_eq!(
1012            snapshot.clip_point(BlockPoint::new(3, 0), Bias::Left),
1013            BlockPoint::new(3, 0)
1014        );
1015        assert_eq!(
1016            snapshot.clip_point(BlockPoint::new(3, 0), Bias::Right),
1017            BlockPoint::new(3, 0)
1018        );
1019        assert_eq!(
1020            snapshot.clip_point(BlockPoint::new(5, 3), Bias::Left),
1021            BlockPoint::new(5, 3)
1022        );
1023        assert_eq!(
1024            snapshot.clip_point(BlockPoint::new(5, 3), Bias::Right),
1025            BlockPoint::new(5, 3)
1026        );
1027        assert_eq!(
1028            snapshot.clip_point(BlockPoint::new(6, 0), Bias::Left),
1029            BlockPoint::new(5, 3)
1030        );
1031        assert_eq!(
1032            snapshot.clip_point(BlockPoint::new(6, 0), Bias::Right),
1033            BlockPoint::new(5, 3)
1034        );
1035
1036        assert_eq!(
1037            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1038            &[Some(0), None, None, Some(1), Some(2), Some(3), None]
1039        );
1040
1041        // Insert a line break, separating two block decorations into separate
1042        // lines.
1043        buffer.update(cx, |buffer, cx| {
1044            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx)
1045        });
1046
1047        let (folds_snapshot, fold_edits) = fold_map.read(cx);
1048        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1049        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1050            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1051        });
1052        let mut snapshot = block_map.read(wraps_snapshot, wrap_edits, cx);
1053        assert_eq!(
1054            snapshot.text(),
1055            "aaa\nBLOCK 1\nb!!!\nBLOCK 2\nbb\nccc\nddd\nBLOCK 3"
1056        );
1057    }
1058
1059    #[gpui::test]
1060    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1061        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1062        let font_id = cx
1063            .font_cache()
1064            .select_font(family_id, &Default::default())
1065            .unwrap();
1066
1067        let text = "one two three\nfour five six\nseven eight";
1068
1069        let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
1070        let (_, folds_snapshot) = FoldMap::new(buffer.clone(), cx);
1071        let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
1072        let (_, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, Some(60.), cx);
1073        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot.clone());
1074
1075        let mut writer = block_map.write(wraps_snapshot.clone(), vec![], cx);
1076        writer.insert(
1077            vec![
1078                BlockProperties {
1079                    position: Point::new(1, 12),
1080                    text: "<BLOCK 1",
1081                    disposition: BlockDisposition::Above,
1082                    runs: vec![],
1083                },
1084                BlockProperties {
1085                    position: Point::new(1, 1),
1086                    text: ">BLOCK 2",
1087                    disposition: BlockDisposition::Below,
1088                    runs: vec![],
1089                },
1090            ],
1091            cx,
1092        );
1093
1094        // Blocks with an 'above' disposition go above their corresponding buffer line.
1095        // Blocks with a 'below' disposition go below their corresponding buffer line.
1096        let mut snapshot = block_map.read(wraps_snapshot, vec![], cx);
1097        assert_eq!(
1098            snapshot.text(),
1099            "one two \nthree\n<BLOCK 1\nfour five \nsix\n>BLOCK 2\nseven \neight"
1100        );
1101    }
1102
1103    #[gpui::test(iterations = 100)]
1104    fn test_random_blocks(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
1105        let operations = env::var("OPERATIONS")
1106            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1107            .unwrap_or(10);
1108
1109        let wrap_width = if rng.gen_bool(0.2) {
1110            None
1111        } else {
1112            Some(rng.gen_range(0.0..=100.0))
1113        };
1114        let tab_size = 1;
1115        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1116        let font_id = cx
1117            .font_cache()
1118            .select_font(family_id, &Default::default())
1119            .unwrap();
1120        let font_size = 14.0;
1121
1122        log::info!("Wrap width: {:?}", wrap_width);
1123
1124        let buffer = cx.add_model(|cx| {
1125            let len = rng.gen_range(0..10);
1126            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1127            log::info!("initial buffer text: {:?}", text);
1128            Buffer::new(0, text, cx)
1129        });
1130        let (fold_map, folds_snapshot) = FoldMap::new(buffer.clone(), cx);
1131        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1132        let (wrap_map, wraps_snapshot) =
1133            WrapMap::new(tabs_snapshot, font_id, font_size, wrap_width, cx);
1134        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot);
1135        let mut expected_blocks = Vec::new();
1136
1137        for _ in 0..operations {
1138            match rng.gen_range(0..=100) {
1139                0..=19 => {
1140                    let wrap_width = if rng.gen_bool(0.2) {
1141                        None
1142                    } else {
1143                        Some(rng.gen_range(0.0..=100.0))
1144                    };
1145                    log::info!("Setting wrap width to {:?}", wrap_width);
1146                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1147                }
1148                20..=39 => {
1149                    let block_count = rng.gen_range(1..=1);
1150                    let block_properties = (0..block_count)
1151                        .map(|_| {
1152                            let buffer = buffer.read(cx);
1153                            let position = buffer.anchor_before(
1154                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1155                            );
1156
1157                            let len = rng.gen_range(0..10);
1158                            let mut text = Rope::from(
1159                                RandomCharIter::new(&mut rng)
1160                                    .take(len)
1161                                    .collect::<String>()
1162                                    .to_uppercase()
1163                                    .as_str(),
1164                            );
1165                            let disposition = if rng.gen() {
1166                                text.push_front("<");
1167                                BlockDisposition::Above
1168                            } else {
1169                                text.push_front(">");
1170                                BlockDisposition::Below
1171                            };
1172                            log::info!(
1173                                "inserting block {:?} {:?} with text {:?}",
1174                                disposition,
1175                                position.to_point(buffer),
1176                                text.to_string()
1177                            );
1178                            BlockProperties {
1179                                position,
1180                                text,
1181                                runs: Vec::<(usize, HighlightStyle)>::new(),
1182                                disposition,
1183                            }
1184                        })
1185                        .collect::<Vec<_>>();
1186
1187                    let (folds_snapshot, fold_edits) = fold_map.read(cx);
1188                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1189                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1190                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1191                    });
1192                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits, cx);
1193                    let block_ids = block_map.insert(block_properties.clone(), cx);
1194                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1195                        expected_blocks.push((block_id, props));
1196                    }
1197                }
1198                40..=59 if !expected_blocks.is_empty() => {
1199                    let block_count = rng.gen_range(1..=4.min(expected_blocks.len()));
1200                    let block_ids_to_remove = (0..block_count)
1201                        .map(|_| {
1202                            expected_blocks
1203                                .remove(rng.gen_range(0..expected_blocks.len()))
1204                                .0
1205                        })
1206                        .collect();
1207
1208                    let (folds_snapshot, fold_edits) = fold_map.read(cx);
1209                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1210                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1211                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1212                    });
1213                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits, cx);
1214                    block_map.remove(block_ids_to_remove, cx);
1215                }
1216                _ => {
1217                    buffer.update(cx, |buffer, _| {
1218                        buffer.randomly_edit(&mut rng, 1);
1219                        log::info!("buffer text: {:?}", buffer.text());
1220                    });
1221                }
1222            }
1223
1224            let (folds_snapshot, fold_edits) = fold_map.read(cx);
1225            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1226            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1227                wrap_map.sync(tabs_snapshot, tab_edits, cx)
1228            });
1229            let mut blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits, cx);
1230            assert_eq!(
1231                blocks_snapshot.transforms.summary().input_rows,
1232                wraps_snapshot.max_point().row() + 1
1233            );
1234            log::info!("blocks text: {:?}", blocks_snapshot.text());
1235
1236            let buffer = buffer.read(cx);
1237            let mut sorted_blocks = expected_blocks
1238                .iter()
1239                .cloned()
1240                .map(|(id, block)| {
1241                    let mut position = block.position.to_point(buffer);
1242                    match block.disposition {
1243                        BlockDisposition::Above => {
1244                            position.column = 0;
1245                        }
1246                        BlockDisposition::Below => {
1247                            position.column = buffer.line_len(position.row);
1248                        }
1249                    };
1250                    let row = wraps_snapshot.from_point(position, Bias::Left).row();
1251                    (
1252                        id,
1253                        BlockProperties {
1254                            position: row,
1255                            text: block.text,
1256                            runs: block.runs,
1257                            disposition: block.disposition,
1258                        },
1259                    )
1260                })
1261                .collect::<Vec<_>>();
1262            sorted_blocks
1263                .sort_unstable_by_key(|(id, block)| (block.position, block.disposition, *id));
1264            let mut sorted_blocks = sorted_blocks.into_iter().peekable();
1265
1266            let mut expected_buffer_rows = Vec::new();
1267            let mut expected_text = String::new();
1268            let input_text = wraps_snapshot.text();
1269            for (row, input_line) in input_text.split('\n').enumerate() {
1270                let row = row as u32;
1271                if row > 0 {
1272                    expected_text.push('\n');
1273                }
1274
1275                let buffer_row = wraps_snapshot
1276                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1277                    .row;
1278
1279                while let Some((_, block)) = sorted_blocks.peek() {
1280                    if block.position == row && block.disposition == BlockDisposition::Above {
1281                        let text = block.text.to_string();
1282                        expected_text.push_str(&text);
1283                        expected_text.push('\n');
1284                        for _ in text.split('\n') {
1285                            expected_buffer_rows.push(None);
1286                        }
1287                        sorted_blocks.next();
1288                    } else {
1289                        break;
1290                    }
1291                }
1292
1293                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1294                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
1295                expected_text.push_str(input_line);
1296
1297                while let Some((_, block)) = sorted_blocks.peek() {
1298                    if block.position == row && block.disposition == BlockDisposition::Below {
1299                        let text = block.text.to_string();
1300                        expected_text.push('\n');
1301                        expected_text.push_str(&text);
1302                        for _ in text.split('\n') {
1303                            expected_buffer_rows.push(None);
1304                        }
1305                        sorted_blocks.next();
1306                    } else {
1307                        break;
1308                    }
1309                }
1310            }
1311
1312            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1313            let expected_row_count = expected_lines.len();
1314            for start_row in 0..expected_row_count {
1315                let expected_text = expected_lines[start_row..].join("\n");
1316                let actual_text = blocks_snapshot
1317                    .chunks(start_row as u32..expected_row_count as u32, false)
1318                    .map(|chunk| chunk.text)
1319                    .collect::<String>();
1320                assert_eq!(
1321                    actual_text, expected_text,
1322                    "incorrect text starting from row {}",
1323                    start_row
1324                );
1325            }
1326
1327            let mut expected_longest_rows = Vec::new();
1328            let mut longest_line_len = -1_isize;
1329            for (row, line) in expected_lines.iter().enumerate() {
1330                let row = row as u32;
1331
1332                assert_eq!(
1333                    blocks_snapshot.line_len(row),
1334                    line.len() as u32,
1335                    "invalid line len for row {}",
1336                    row
1337                );
1338
1339                let line_char_count = line.chars().count() as isize;
1340                match line_char_count.cmp(&longest_line_len) {
1341                    Ordering::Less => {}
1342                    Ordering::Equal => expected_longest_rows.push(row),
1343                    Ordering::Greater => {
1344                        longest_line_len = line_char_count;
1345                        expected_longest_rows.clear();
1346                        expected_longest_rows.push(row);
1347                    }
1348                }
1349            }
1350
1351            log::info!("getting longest row >>>>>>>>>>>>>>>>>>>>>>>>");
1352            let longest_row = blocks_snapshot.longest_row();
1353            assert!(
1354                expected_longest_rows.contains(&longest_row),
1355                "incorrect longest row {}. expected {:?} with length {}",
1356                longest_row,
1357                expected_longest_rows,
1358                longest_line_len,
1359            );
1360
1361            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1362                let wrap_point = WrapPoint::new(row, 0);
1363                let block_point = blocks_snapshot.to_block_point(wrap_point);
1364                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1365            }
1366            assert_eq!(
1367                blocks_snapshot.buffer_rows(0).collect::<Vec<_>>(),
1368                expected_buffer_rows
1369            );
1370
1371            let mut block_point = BlockPoint::new(0, 0);
1372            for c in expected_text.chars() {
1373                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1374                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1375
1376                assert_eq!(
1377                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1378                    left_point
1379                );
1380                assert_eq!(
1381                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1382                    right_point
1383                );
1384
1385                if c == '\n' {
1386                    block_point.0 += Point::new(1, 0);
1387                } else {
1388                    block_point.column += c.len_utf8() as u32;
1389                }
1390            }
1391        }
1392    }
1393}