block_map.rs

   1use super::wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot};
   2use crate::{Anchor, ToOffset, ToPoint as _};
   3use collections::{HashMap, HashSet};
   4use gpui::{AppContext, ElementBox};
   5use language::Chunk;
   6use parking_lot::Mutex;
   7use std::{
   8    cmp::{self, Ordering},
   9    fmt::Debug,
  10    ops::{Deref, Range},
  11    sync::{
  12        atomic::{AtomicUsize, Ordering::SeqCst},
  13        Arc,
  14    },
  15};
  16use sum_tree::{Bias, SumTree};
  17use text::{Edit, Point};
  18use theme::SyntaxTheme;
  19
  20const NEWLINES: &'static [u8] = &[b'\n'; u8::MAX as usize];
  21
  22pub struct BlockMap {
  23    next_block_id: AtomicUsize,
  24    wrap_snapshot: Mutex<WrapSnapshot>,
  25    blocks: Vec<Arc<Block>>,
  26    transforms: Mutex<SumTree<Transform>>,
  27}
  28
  29pub struct BlockMapWriter<'a>(&'a mut BlockMap);
  30
  31pub struct BlockSnapshot {
  32    wrap_snapshot: WrapSnapshot,
  33    transforms: SumTree<Transform>,
  34}
  35
  36#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
  37pub struct BlockId(usize);
  38
  39#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  40pub struct BlockPoint(pub super::Point);
  41
  42#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  43struct BlockRow(u32);
  44
  45#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  46struct WrapRow(u32);
  47
  48pub type RenderBlock = Arc<dyn Fn(&BlockContext) -> ElementBox>;
  49
  50pub struct Block {
  51    id: BlockId,
  52    position: Anchor,
  53    height: u8,
  54    render: Mutex<RenderBlock>,
  55    disposition: BlockDisposition,
  56}
  57
  58#[derive(Clone)]
  59pub struct BlockProperties<P>
  60where
  61    P: Clone,
  62{
  63    pub position: P,
  64    pub height: u8,
  65    pub render: Arc<dyn Fn(&BlockContext) -> ElementBox>,
  66    pub disposition: BlockDisposition,
  67}
  68
  69pub struct BlockContext<'a> {
  70    pub cx: &'a AppContext,
  71    pub anchor_x: f32,
  72}
  73
  74#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  75pub enum BlockDisposition {
  76    Above,
  77    Below,
  78}
  79
  80#[derive(Clone, Debug)]
  81struct Transform {
  82    summary: TransformSummary,
  83    block: Option<AlignedBlock>,
  84}
  85
  86#[derive(Clone, Debug)]
  87pub struct AlignedBlock {
  88    block: Arc<Block>,
  89    column: u32,
  90}
  91
  92#[derive(Clone, Debug, Default)]
  93struct TransformSummary {
  94    input_rows: u32,
  95    output_rows: u32,
  96}
  97
  98pub struct BlockChunks<'a> {
  99    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 100    input_chunks: wrap_map::WrapChunks<'a>,
 101    input_chunk: Chunk<'a>,
 102    output_row: u32,
 103    max_output_row: u32,
 104}
 105
 106pub struct BlockBufferRows<'a> {
 107    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 108    input_buffer_rows: wrap_map::WrapBufferRows<'a>,
 109    output_row: u32,
 110    started: bool,
 111}
 112
 113impl BlockMap {
 114    pub fn new(wrap_snapshot: WrapSnapshot) -> Self {
 115        Self {
 116            next_block_id: AtomicUsize::new(0),
 117            blocks: Vec::new(),
 118            transforms: Mutex::new(SumTree::from_item(
 119                Transform::isomorphic(wrap_snapshot.text_summary().lines.row + 1),
 120                &(),
 121            )),
 122            wrap_snapshot: Mutex::new(wrap_snapshot),
 123        }
 124    }
 125
 126    pub fn read(&self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockSnapshot {
 127        self.sync(&wrap_snapshot, edits);
 128        *self.wrap_snapshot.lock() = wrap_snapshot.clone();
 129        BlockSnapshot {
 130            wrap_snapshot,
 131            transforms: self.transforms.lock().clone(),
 132        }
 133    }
 134
 135    pub fn write(&mut self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockMapWriter {
 136        self.sync(&wrap_snapshot, edits);
 137        *self.wrap_snapshot.lock() = wrap_snapshot;
 138        BlockMapWriter(self)
 139    }
 140
 141    fn sync(&self, wrap_snapshot: &WrapSnapshot, edits: Vec<WrapEdit>) {
 142        if edits.is_empty() {
 143            return;
 144        }
 145
 146        let buffer = wrap_snapshot.buffer_snapshot();
 147        let mut transforms = self.transforms.lock();
 148        let mut new_transforms = SumTree::new();
 149        let old_row_count = transforms.summary().input_rows;
 150        let new_row_count = wrap_snapshot.max_point().row() + 1;
 151        let mut cursor = transforms.cursor::<WrapRow>();
 152        let mut last_block_ix = 0;
 153        let mut blocks_in_edit = Vec::new();
 154        let mut edits = edits.into_iter().peekable();
 155
 156        while let Some(edit) = edits.next() {
 157            // Preserve any old transforms that precede this edit.
 158            let old_start = WrapRow(edit.old.start);
 159            let new_start = WrapRow(edit.new.start);
 160            new_transforms.push_tree(cursor.slice(&old_start, Bias::Left, &()), &());
 161            if let Some(transform) = cursor.item() {
 162                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 163                    new_transforms.push(transform.clone(), &());
 164                    cursor.next(&());
 165                    while let Some(transform) = cursor.item() {
 166                        if transform
 167                            .block
 168                            .as_ref()
 169                            .map_or(false, |b| b.disposition.is_below())
 170                        {
 171                            new_transforms.push(transform.clone(), &());
 172                            cursor.next(&());
 173                        } else {
 174                            break;
 175                        }
 176                    }
 177                }
 178            }
 179
 180            // Preserve any portion of an old transform that precedes this edit.
 181            let extent_before_edit = old_start.0 - cursor.start().0;
 182            push_isomorphic(&mut new_transforms, extent_before_edit);
 183
 184            // Skip over any old transforms that intersect this edit.
 185            let mut old_end = WrapRow(edit.old.end);
 186            let mut new_end = WrapRow(edit.new.end);
 187            cursor.seek(&old_end, Bias::Left, &());
 188            cursor.next(&());
 189            if old_end == *cursor.start() {
 190                while let Some(transform) = cursor.item() {
 191                    if transform
 192                        .block
 193                        .as_ref()
 194                        .map_or(false, |b| b.disposition.is_below())
 195                    {
 196                        cursor.next(&());
 197                    } else {
 198                        break;
 199                    }
 200                }
 201            }
 202
 203            // Combine this edit with any subsequent edits that intersect the same transform.
 204            while let Some(next_edit) = edits.peek() {
 205                if next_edit.old.start <= cursor.start().0 {
 206                    old_end = WrapRow(next_edit.old.end);
 207                    new_end = WrapRow(next_edit.new.end);
 208                    cursor.seek(&old_end, Bias::Left, &());
 209                    cursor.next(&());
 210                    if old_end == *cursor.start() {
 211                        while let Some(transform) = cursor.item() {
 212                            if transform
 213                                .block
 214                                .as_ref()
 215                                .map_or(false, |b| b.disposition.is_below())
 216                            {
 217                                cursor.next(&());
 218                            } else {
 219                                break;
 220                            }
 221                        }
 222                    }
 223                    edits.next();
 224                } else {
 225                    break;
 226                }
 227            }
 228
 229            // Find the blocks within this edited region.
 230            let new_buffer_start =
 231                wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 232            let start_anchor = buffer.anchor_before(new_buffer_start);
 233            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 234                probe
 235                    .position
 236                    .cmp(&start_anchor, &buffer)
 237                    .unwrap()
 238                    .then(Ordering::Greater)
 239            }) {
 240                Ok(ix) | Err(ix) => last_block_ix + ix,
 241            };
 242
 243            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 244                self.blocks.len()
 245            } else {
 246                let new_buffer_end =
 247                    wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 248                let end_anchor = buffer.anchor_before(new_buffer_end);
 249                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 250                    probe
 251                        .position
 252                        .cmp(&end_anchor, &buffer)
 253                        .unwrap()
 254                        .then(Ordering::Greater)
 255                }) {
 256                    Ok(ix) | Err(ix) => start_block_ix + ix,
 257                }
 258            };
 259            last_block_ix = end_block_ix;
 260
 261            debug_assert!(blocks_in_edit.is_empty());
 262            blocks_in_edit.extend(
 263                self.blocks[start_block_ix..end_block_ix]
 264                    .iter()
 265                    .map(|block| {
 266                        let mut position = block.position.to_point(&buffer);
 267                        let column = wrap_snapshot.from_point(position, Bias::Left).column();
 268                        match block.disposition {
 269                            BlockDisposition::Above => position.column = 0,
 270                            BlockDisposition::Below => {
 271                                position.column = buffer.line_len(position.row)
 272                            }
 273                        }
 274                        let position = wrap_snapshot.from_point(position, Bias::Left);
 275                        (position.row(), column, block.clone())
 276                    }),
 277            );
 278            blocks_in_edit.sort_by_key(|(row, _, block)| (*row, block.disposition, block.id));
 279
 280            // For each of these blocks, insert a new isomorphic transform preceding the block,
 281            // and then insert the block itself.
 282            for (block_row, column, block) in blocks_in_edit.drain(..) {
 283                let insertion_row = match block.disposition {
 284                    BlockDisposition::Above => block_row,
 285                    BlockDisposition::Below => block_row + 1,
 286                };
 287                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 288                push_isomorphic(&mut new_transforms, extent_before_block);
 289                new_transforms.push(Transform::block(block, column), &());
 290            }
 291
 292            old_end = WrapRow(old_end.0.min(old_row_count));
 293            new_end = WrapRow(new_end.0.min(new_row_count));
 294
 295            // Insert an isomorphic transform after the final block.
 296            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 297            push_isomorphic(&mut new_transforms, extent_after_last_block);
 298
 299            // Preserve any portion of the old transform after this edit.
 300            let extent_after_edit = cursor.start().0 - old_end.0;
 301            push_isomorphic(&mut new_transforms, extent_after_edit);
 302        }
 303
 304        new_transforms.push_tree(cursor.suffix(&()), &());
 305        debug_assert_eq!(
 306            new_transforms.summary().input_rows,
 307            wrap_snapshot.max_point().row() + 1
 308        );
 309
 310        drop(cursor);
 311        *transforms = new_transforms;
 312    }
 313
 314    pub fn replace(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 315        for block in &self.blocks {
 316            if let Some(render) = renderers.remove(&block.id) {
 317                *block.render.lock() = render;
 318            }
 319        }
 320    }
 321}
 322
 323fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 324    if rows == 0 {
 325        return;
 326    }
 327
 328    let mut extent = Some(rows);
 329    tree.update_last(
 330        |last_transform| {
 331            if last_transform.is_isomorphic() {
 332                let extent = extent.take().unwrap();
 333                last_transform.summary.input_rows += extent;
 334                last_transform.summary.output_rows += extent;
 335            }
 336        },
 337        &(),
 338    );
 339    if let Some(extent) = extent {
 340        tree.push(Transform::isomorphic(extent), &());
 341    }
 342}
 343
 344impl BlockPoint {
 345    pub fn new(row: u32, column: u32) -> Self {
 346        Self(Point::new(row, column))
 347    }
 348}
 349
 350impl Deref for BlockPoint {
 351    type Target = Point;
 352
 353    fn deref(&self) -> &Self::Target {
 354        &self.0
 355    }
 356}
 357
 358impl std::ops::DerefMut for BlockPoint {
 359    fn deref_mut(&mut self) -> &mut Self::Target {
 360        &mut self.0
 361    }
 362}
 363
 364impl<'a> BlockMapWriter<'a> {
 365    pub fn insert<P>(
 366        &mut self,
 367        blocks: impl IntoIterator<Item = BlockProperties<P>>,
 368    ) -> Vec<BlockId>
 369    where
 370        P: ToOffset + Clone,
 371    {
 372        let mut ids = Vec::new();
 373        let mut edits = Vec::<Edit<u32>>::new();
 374        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 375        let buffer = wrap_snapshot.buffer_snapshot();
 376
 377        for block in blocks {
 378            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 379            ids.push(id);
 380
 381            let position = buffer.anchor_after(block.position);
 382            let point = position.to_point(&buffer);
 383            let wrap_row = wrap_snapshot
 384                .from_point(Point::new(point.row, 0), Bias::Left)
 385                .row();
 386            let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 387            let end_row = wrap_snapshot
 388                .next_row_boundary(WrapPoint::new(wrap_row, 0))
 389                .unwrap_or(wrap_snapshot.max_point().row() + 1);
 390
 391            let block_ix = match self
 392                .0
 393                .blocks
 394                .binary_search_by(|probe| probe.position.cmp(&position, &buffer).unwrap())
 395            {
 396                Ok(ix) | Err(ix) => ix,
 397            };
 398            self.0.blocks.insert(
 399                block_ix,
 400                Arc::new(Block {
 401                    id,
 402                    position,
 403                    height: block.height,
 404                    render: Mutex::new(block.render),
 405                    disposition: block.disposition,
 406                }),
 407            );
 408
 409            if let Err(edit_ix) = edits.binary_search_by_key(&start_row, |edit| edit.old.start) {
 410                edits.insert(
 411                    edit_ix,
 412                    Edit {
 413                        old: start_row..end_row,
 414                        new: start_row..end_row,
 415                    },
 416                );
 417            }
 418        }
 419
 420        self.0.sync(wrap_snapshot, edits);
 421        ids
 422    }
 423
 424    pub fn remove(&mut self, block_ids: HashSet<BlockId>) {
 425        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 426        let buffer = wrap_snapshot.buffer_snapshot();
 427        let mut edits = Vec::new();
 428        let mut last_block_buffer_row = None;
 429        self.0.blocks.retain(|block| {
 430            if block_ids.contains(&block.id) {
 431                let buffer_row = block.position.to_point(&buffer).row;
 432                if last_block_buffer_row != Some(buffer_row) {
 433                    last_block_buffer_row = Some(buffer_row);
 434                    let wrap_row = wrap_snapshot
 435                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 436                        .row();
 437                    let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 438                    let end_row = wrap_snapshot
 439                        .next_row_boundary(WrapPoint::new(wrap_row, 0))
 440                        .unwrap_or(wrap_snapshot.max_point().row() + 1);
 441                    edits.push(Edit {
 442                        old: start_row..end_row,
 443                        new: start_row..end_row,
 444                    })
 445                }
 446                false
 447            } else {
 448                true
 449            }
 450        });
 451        self.0.sync(wrap_snapshot, edits);
 452    }
 453}
 454
 455impl BlockSnapshot {
 456    #[cfg(test)]
 457    pub fn text(&self) -> String {
 458        self.chunks(0..self.transforms.summary().output_rows, None)
 459            .map(|chunk| chunk.text)
 460            .collect()
 461    }
 462
 463    pub fn chunks<'a>(
 464        &'a self,
 465        rows: Range<u32>,
 466        theme: Option<&'a SyntaxTheme>,
 467    ) -> BlockChunks<'a> {
 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        BlockChunks {
 495            input_chunks: self.wrap_snapshot.chunks(input_start..input_end, theme),
 496            input_chunk: Default::default(),
 497            transforms: cursor,
 498            output_row: rows.start,
 499            max_output_row,
 500        }
 501    }
 502
 503    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> BlockBufferRows<'a> {
 504        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 505        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 506        let (output_start, input_start) = cursor.start();
 507        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 508            start_row - output_start.0
 509        } else {
 510            0
 511        };
 512        let input_start_row = input_start.0 + overshoot;
 513        BlockBufferRows {
 514            transforms: cursor,
 515            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 516            output_row: start_row,
 517            started: false,
 518        }
 519    }
 520
 521    pub fn blocks_in_range<'a>(
 522        &'a self,
 523        rows: Range<u32>,
 524    ) -> impl Iterator<Item = (u32, &'a AlignedBlock)> {
 525        let mut cursor = self.transforms.cursor::<BlockRow>();
 526        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 527        std::iter::from_fn(move || {
 528            while let Some(transform) = cursor.item() {
 529                let start_row = cursor.start().0;
 530                if start_row >= rows.end {
 531                    break;
 532                }
 533                if let Some(block) = &transform.block {
 534                    cursor.next(&());
 535                    return Some((start_row, block));
 536                } else {
 537                    cursor.next(&());
 538                }
 539            }
 540            None
 541        })
 542    }
 543
 544    pub fn max_point(&self) -> BlockPoint {
 545        let row = self.transforms.summary().output_rows - 1;
 546        BlockPoint::new(row, self.line_len(row))
 547    }
 548
 549    pub fn longest_row(&self) -> u32 {
 550        let input_row = self.wrap_snapshot.longest_row();
 551        self.to_block_point(WrapPoint::new(input_row, 0)).row
 552    }
 553
 554    pub fn line_len(&self, row: u32) -> u32 {
 555        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 556        cursor.seek(&BlockRow(row), Bias::Right, &());
 557        if let Some(transform) = cursor.item() {
 558            let (output_start, input_start) = cursor.start();
 559            let overshoot = row - output_start.0;
 560            if transform.block.is_some() {
 561                0
 562            } else {
 563                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 564            }
 565        } else {
 566            panic!("row out of range");
 567        }
 568    }
 569
 570    pub fn is_block_line(&self, row: u32) -> bool {
 571        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 572        cursor.seek(&BlockRow(row), Bias::Right, &());
 573        cursor.item().map_or(false, |t| t.block.is_some())
 574    }
 575
 576    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 577        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 578        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 579
 580        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 581        let mut search_left =
 582            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 583        let mut reversed = false;
 584
 585        loop {
 586            if let Some(transform) = cursor.item() {
 587                if transform.is_isomorphic() {
 588                    let (output_start_row, input_start_row) = cursor.start();
 589                    let (output_end_row, input_end_row) = cursor.end(&());
 590                    let output_start = Point::new(output_start_row.0, 0);
 591                    let input_start = Point::new(input_start_row.0, 0);
 592                    let input_end = Point::new(input_end_row.0, 0);
 593                    let input_point = if point.row >= output_end_row.0 {
 594                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 595                        self.wrap_snapshot
 596                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 597                    } else {
 598                        let output_overshoot = point.0.saturating_sub(output_start);
 599                        self.wrap_snapshot
 600                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 601                    };
 602
 603                    if (input_start..input_end).contains(&input_point.0) {
 604                        let input_overshoot = input_point.0.saturating_sub(input_start);
 605                        return BlockPoint(output_start + input_overshoot);
 606                    }
 607                }
 608
 609                if search_left {
 610                    cursor.prev(&());
 611                } else {
 612                    cursor.next(&());
 613                }
 614            } else if reversed {
 615                return self.max_point();
 616            } else {
 617                reversed = true;
 618                search_left = !search_left;
 619                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 620            }
 621        }
 622    }
 623
 624    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 625        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 626        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 627        if let Some(transform) = cursor.item() {
 628            debug_assert!(transform.is_isomorphic());
 629        } else {
 630            return self.max_point();
 631        }
 632
 633        let (input_start_row, output_start_row) = cursor.start();
 634        let input_start = Point::new(input_start_row.0, 0);
 635        let output_start = Point::new(output_start_row.0, 0);
 636        let input_overshoot = wrap_point.0 - input_start;
 637        BlockPoint(output_start + input_overshoot)
 638    }
 639
 640    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 641        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 642        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 643        if let Some(transform) = cursor.item() {
 644            match transform.block.as_ref().map(|b| b.disposition) {
 645                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 646                Some(BlockDisposition::Below) => {
 647                    let wrap_row = cursor.start().1 .0 - 1;
 648                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 649                }
 650                None => {
 651                    let overshoot = block_point.row - cursor.start().0 .0;
 652                    let wrap_row = cursor.start().1 .0 + overshoot;
 653                    WrapPoint::new(wrap_row, block_point.column)
 654                }
 655            }
 656        } else {
 657            self.wrap_snapshot.max_point()
 658        }
 659    }
 660}
 661
 662impl Transform {
 663    fn isomorphic(rows: u32) -> Self {
 664        Self {
 665            summary: TransformSummary {
 666                input_rows: rows,
 667                output_rows: rows,
 668            },
 669            block: None,
 670        }
 671    }
 672
 673    fn block(block: Arc<Block>, column: u32) -> Self {
 674        Self {
 675            summary: TransformSummary {
 676                input_rows: 0,
 677                output_rows: block.height as u32,
 678            },
 679            block: Some(AlignedBlock { block, column }),
 680        }
 681    }
 682
 683    fn is_isomorphic(&self) -> bool {
 684        self.block.is_none()
 685    }
 686}
 687
 688impl<'a> Iterator for BlockChunks<'a> {
 689    type Item = Chunk<'a>;
 690
 691    fn next(&mut self) -> Option<Self::Item> {
 692        if self.output_row >= self.max_output_row {
 693            return None;
 694        }
 695
 696        let transform = self.transforms.item()?;
 697        if transform.block.is_some() {
 698            let block_start = self.transforms.start().0 .0;
 699            let mut block_end = self.transforms.end(&()).0 .0;
 700            self.transforms.next(&());
 701            if self.transforms.item().is_none() {
 702                block_end -= 1;
 703            }
 704
 705            let start_in_block = self.output_row - block_start;
 706            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 707            let line_count = end_in_block - start_in_block;
 708            self.output_row += line_count;
 709
 710            return Some(Chunk {
 711                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 712                highlight_style: None,
 713                diagnostic: None,
 714            });
 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> Iterator for BlockBufferRows<'a> {
 752    type Item = Option<u32>;
 753
 754    fn next(&mut self) -> Option<Self::Item> {
 755        if self.started {
 756            self.output_row += 1;
 757        } else {
 758            self.started = true;
 759        }
 760
 761        if self.output_row >= self.transforms.end(&()).0 .0 {
 762            self.transforms.next(&());
 763        }
 764
 765        let transform = self.transforms.item()?;
 766        if transform.block.is_some() {
 767            Some(None)
 768        } else {
 769            Some(self.input_buffer_rows.next().unwrap())
 770        }
 771    }
 772}
 773
 774impl sum_tree::Item for Transform {
 775    type Summary = TransformSummary;
 776
 777    fn summary(&self) -> Self::Summary {
 778        self.summary.clone()
 779    }
 780}
 781
 782impl sum_tree::Summary for TransformSummary {
 783    type Context = ();
 784
 785    fn add_summary(&mut self, summary: &Self, _: &()) {
 786        self.input_rows += summary.input_rows;
 787        self.output_rows += summary.output_rows;
 788    }
 789}
 790
 791impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 792    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 793        self.0 += summary.input_rows;
 794    }
 795}
 796
 797impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 798    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 799        self.0 += summary.output_rows;
 800    }
 801}
 802
 803impl BlockDisposition {
 804    fn is_below(&self) -> bool {
 805        matches!(self, BlockDisposition::Below)
 806    }
 807}
 808
 809impl AlignedBlock {
 810    pub fn height(&self) -> u32 {
 811        self.height as u32
 812    }
 813
 814    pub fn column(&self) -> u32 {
 815        self.column
 816    }
 817
 818    pub fn render(&self, cx: &BlockContext) -> ElementBox {
 819        self.render.lock()(cx)
 820    }
 821
 822    pub fn position(&self) -> &Anchor {
 823        &self.block.position
 824    }
 825}
 826
 827impl Deref for AlignedBlock {
 828    type Target = Block;
 829
 830    fn deref(&self) -> &Self::Target {
 831        self.block.as_ref()
 832    }
 833}
 834
 835impl<'a> Deref for BlockContext<'a> {
 836    type Target = AppContext;
 837
 838    fn deref(&self) -> &Self::Target {
 839        &self.cx
 840    }
 841}
 842
 843impl Debug for Block {
 844    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 845        f.debug_struct("Block")
 846            .field("id", &self.id)
 847            .field("position", &self.position)
 848            .field("disposition", &self.disposition)
 849            .finish()
 850    }
 851}
 852
 853// Count the number of bytes prior to a target point. If the string doesn't contain the target
 854// point, return its total extent. Otherwise return the target point itself.
 855fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 856    let mut row = 0;
 857    let mut offset = 0;
 858    for (ix, line) in s.split('\n').enumerate() {
 859        if ix > 0 {
 860            row += 1;
 861            offset += 1;
 862        }
 863        if row >= target {
 864            break;
 865        }
 866        offset += line.len() as usize;
 867    }
 868    (row, offset)
 869}
 870
 871#[cfg(test)]
 872mod tests {
 873    use super::*;
 874    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 875    use crate::multi_buffer::MultiBuffer;
 876    use gpui::{elements::Empty, Element};
 877    use rand::prelude::*;
 878    use std::env;
 879    use text::RandomCharIter;
 880
 881    #[gpui::test]
 882    fn test_offset_for_row() {
 883        assert_eq!(offset_for_row("", 0), (0, 0));
 884        assert_eq!(offset_for_row("", 1), (0, 0));
 885        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 886        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 887        assert_eq!(offset_for_row("\n", 0), (0, 0));
 888        assert_eq!(offset_for_row("\n", 1), (1, 1));
 889        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 890        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 891        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 892        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 893    }
 894
 895    #[gpui::test]
 896    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 897        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 898        let font_id = cx
 899            .font_cache()
 900            .select_font(family_id, &Default::default())
 901            .unwrap();
 902
 903        let text = "aaa\nbbb\nccc\nddd";
 904
 905        let buffer = MultiBuffer::build_simple(text, cx);
 906        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
 907        let (fold_map, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot(cx));
 908        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 909        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 910        let mut block_map = BlockMap::new(wraps_snapshot.clone());
 911
 912        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
 913        writer.insert(vec![
 914            BlockProperties {
 915                position: Point::new(1, 0),
 916                height: 1,
 917                disposition: BlockDisposition::Above,
 918                render: Arc::new(|_| Empty::new().named("block 1")),
 919            },
 920            BlockProperties {
 921                position: Point::new(1, 2),
 922                height: 2,
 923                disposition: BlockDisposition::Above,
 924                render: Arc::new(|_| Empty::new().named("block 2")),
 925            },
 926            BlockProperties {
 927                position: Point::new(3, 3),
 928                height: 3,
 929                disposition: BlockDisposition::Below,
 930                render: Arc::new(|_| Empty::new().named("block 3")),
 931            },
 932        ]);
 933
 934        let snapshot = block_map.read(wraps_snapshot, vec![]);
 935        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
 936
 937        let blocks = snapshot
 938            .blocks_in_range(0..8)
 939            .map(|(start_row, block)| {
 940                (
 941                    start_row..start_row + block.height(),
 942                    block.column(),
 943                    block
 944                        .render(&BlockContext { cx, anchor_x: 0. })
 945                        .name()
 946                        .unwrap()
 947                        .to_string(),
 948                )
 949            })
 950            .collect::<Vec<_>>();
 951        assert_eq!(
 952            blocks,
 953            &[
 954                (1..2, 0, "block 1".to_string()),
 955                (2..4, 2, "block 2".to_string()),
 956                (7..10, 3, "block 3".to_string()),
 957            ]
 958        );
 959
 960        assert_eq!(
 961            snapshot.to_block_point(WrapPoint::new(0, 3)),
 962            BlockPoint::new(0, 3)
 963        );
 964        assert_eq!(
 965            snapshot.to_block_point(WrapPoint::new(1, 0)),
 966            BlockPoint::new(4, 0)
 967        );
 968        assert_eq!(
 969            snapshot.to_block_point(WrapPoint::new(3, 3)),
 970            BlockPoint::new(6, 3)
 971        );
 972
 973        assert_eq!(
 974            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
 975            WrapPoint::new(0, 3)
 976        );
 977        assert_eq!(
 978            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
 979            WrapPoint::new(1, 0)
 980        );
 981        assert_eq!(
 982            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
 983            WrapPoint::new(1, 0)
 984        );
 985        assert_eq!(
 986            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
 987            WrapPoint::new(3, 3)
 988        );
 989
 990        assert_eq!(
 991            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
 992            BlockPoint::new(0, 3)
 993        );
 994        assert_eq!(
 995            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
 996            BlockPoint::new(4, 0)
 997        );
 998        assert_eq!(
 999            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1000            BlockPoint::new(0, 3)
1001        );
1002        assert_eq!(
1003            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1004            BlockPoint::new(4, 0)
1005        );
1006        assert_eq!(
1007            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1008            BlockPoint::new(4, 0)
1009        );
1010        assert_eq!(
1011            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1012            BlockPoint::new(4, 0)
1013        );
1014        assert_eq!(
1015            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1016            BlockPoint::new(6, 3)
1017        );
1018        assert_eq!(
1019            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1020            BlockPoint::new(6, 3)
1021        );
1022        assert_eq!(
1023            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1024            BlockPoint::new(6, 3)
1025        );
1026        assert_eq!(
1027            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1028            BlockPoint::new(6, 3)
1029        );
1030
1031        assert_eq!(
1032            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1033            &[
1034                Some(0),
1035                None,
1036                None,
1037                None,
1038                Some(1),
1039                Some(2),
1040                Some(3),
1041                None,
1042                None,
1043                None
1044            ]
1045        );
1046
1047        // Insert a line break, separating two block decorations into separate lines.
1048        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1049            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
1050            buffer.snapshot(cx)
1051        });
1052
1053        let (folds_snapshot, fold_edits) =
1054            fold_map.read(buffer_snapshot, subscription.consume().into_inner());
1055        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1056        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1057            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1058        });
1059        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1060        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1061    }
1062
1063    #[gpui::test]
1064    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1065        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1066        let font_id = cx
1067            .font_cache()
1068            .select_font(family_id, &Default::default())
1069            .unwrap();
1070
1071        let text = "one two three\nfour five six\nseven eight";
1072
1073        let buffer = MultiBuffer::build_simple(text, cx);
1074        let (_, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot(cx));
1075        let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
1076        let (_, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, Some(60.), cx);
1077        let mut block_map = BlockMap::new(wraps_snapshot.clone());
1078
1079        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
1080        writer.insert(vec![
1081            BlockProperties {
1082                position: Point::new(1, 12),
1083                disposition: BlockDisposition::Above,
1084                render: Arc::new(|_| Empty::new().named("block 1")),
1085                height: 1,
1086            },
1087            BlockProperties {
1088                position: Point::new(1, 1),
1089                disposition: BlockDisposition::Below,
1090                render: Arc::new(|_| Empty::new().named("block 2")),
1091                height: 1,
1092            },
1093        ]);
1094
1095        // Blocks with an 'above' disposition go above their corresponding buffer line.
1096        // Blocks with a 'below' disposition go below their corresponding buffer line.
1097        let snapshot = block_map.read(wraps_snapshot, vec![]);
1098        assert_eq!(
1099            snapshot.text(),
1100            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1101        );
1102    }
1103
1104    #[gpui::test(iterations = 100)]
1105    fn test_random_blocks(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
1106        let operations = env::var("OPERATIONS")
1107            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1108            .unwrap_or(10);
1109
1110        let wrap_width = if rng.gen_bool(0.2) {
1111            None
1112        } else {
1113            Some(rng.gen_range(0.0..=100.0))
1114        };
1115        let tab_size = 1;
1116        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1117        let font_id = cx
1118            .font_cache()
1119            .select_font(family_id, &Default::default())
1120            .unwrap();
1121        let font_size = 14.0;
1122
1123        log::info!("Wrap width: {:?}", wrap_width);
1124
1125        let buffer = if rng.gen() {
1126            let len = rng.gen_range(0..10);
1127            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1128            log::info!("initial buffer text: {:?}", text);
1129            MultiBuffer::build_simple(&text, cx)
1130        } else {
1131            MultiBuffer::build_random(&mut rng, cx)
1132        };
1133
1134        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1135        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1136        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1137        let (wrap_map, wraps_snapshot) =
1138            WrapMap::new(tabs_snapshot, font_id, font_size, wrap_width, cx);
1139        let mut block_map = BlockMap::new(wraps_snapshot);
1140        let mut expected_blocks = Vec::new();
1141
1142        for _ in 0..operations {
1143            let mut buffer_edits = Vec::new();
1144            match rng.gen_range(0..=100) {
1145                0..=19 => {
1146                    let wrap_width = if rng.gen_bool(0.2) {
1147                        None
1148                    } else {
1149                        Some(rng.gen_range(0.0..=100.0))
1150                    };
1151                    log::info!("Setting wrap width to {:?}", wrap_width);
1152                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1153                }
1154                20..=39 => {
1155                    let block_count = rng.gen_range(1..=5);
1156                    let block_properties = (0..block_count)
1157                        .map(|_| {
1158                            let buffer = buffer.read(cx).read(cx);
1159                            let position = buffer.anchor_after(
1160                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1161                            );
1162
1163                            let disposition = if rng.gen() {
1164                                BlockDisposition::Above
1165                            } else {
1166                                BlockDisposition::Below
1167                            };
1168                            let height = rng.gen_range(1..5);
1169                            log::info!(
1170                                "inserting block {:?} {:?} with height {}",
1171                                disposition,
1172                                position.to_point(&buffer),
1173                                height
1174                            );
1175                            BlockProperties {
1176                                position,
1177                                height,
1178                                disposition,
1179                                render: Arc::new(|_| Empty::new().boxed()),
1180                            }
1181                        })
1182                        .collect::<Vec<_>>();
1183
1184                    let (folds_snapshot, fold_edits) =
1185                        fold_map.read(buffer_snapshot.clone(), vec![]);
1186                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1187                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1188                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1189                    });
1190                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1191                    let block_ids = block_map.insert(block_properties.clone());
1192                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1193                        expected_blocks.push((block_id, props));
1194                    }
1195                }
1196                40..=59 if !expected_blocks.is_empty() => {
1197                    let block_count = rng.gen_range(1..=4.min(expected_blocks.len()));
1198                    let block_ids_to_remove = (0..block_count)
1199                        .map(|_| {
1200                            expected_blocks
1201                                .remove(rng.gen_range(0..expected_blocks.len()))
1202                                .0
1203                        })
1204                        .collect();
1205
1206                    let (folds_snapshot, fold_edits) =
1207                        fold_map.read(buffer_snapshot.clone(), vec![]);
1208                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1209                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1210                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1211                    });
1212                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1213                    block_map.remove(block_ids_to_remove);
1214                }
1215                _ => {
1216                    buffer.update(cx, |buffer, cx| {
1217                        let edit_count = rng.gen_range(1..=5);
1218                        let subscription = buffer.subscribe();
1219                        buffer.randomly_edit(&mut rng, edit_count, cx);
1220                        buffer_snapshot = buffer.snapshot(cx);
1221                        buffer_edits.extend(subscription.consume());
1222                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1223                    });
1224                }
1225            }
1226
1227            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1228            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1229            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1230                wrap_map.sync(tabs_snapshot, tab_edits, cx)
1231            });
1232            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1233            assert_eq!(
1234                blocks_snapshot.transforms.summary().input_rows,
1235                wraps_snapshot.max_point().row() + 1
1236            );
1237            log::info!("blocks text: {:?}", blocks_snapshot.text());
1238
1239            let mut sorted_blocks = expected_blocks
1240                .iter()
1241                .cloned()
1242                .map(|(id, block)| {
1243                    let mut position = block.position.to_point(&buffer_snapshot);
1244                    let column = wraps_snapshot.from_point(position, Bias::Left).column();
1245                    match block.disposition {
1246                        BlockDisposition::Above => {
1247                            position.column = 0;
1248                        }
1249                        BlockDisposition::Below => {
1250                            position.column = buffer_snapshot.line_len(position.row);
1251                        }
1252                    };
1253                    let row = wraps_snapshot.from_point(position, Bias::Left).row();
1254                    (
1255                        id,
1256                        BlockProperties {
1257                            position: BlockPoint::new(row, column),
1258                            height: block.height,
1259                            disposition: block.disposition,
1260                            render: block.render.clone(),
1261                        },
1262                    )
1263                })
1264                .collect::<Vec<_>>();
1265            sorted_blocks
1266                .sort_unstable_by_key(|(id, block)| (block.position.row, block.disposition, *id));
1267            let mut sorted_blocks = sorted_blocks.into_iter().peekable();
1268
1269            let input_buffer_rows = buffer_snapshot.buffer_rows(0).collect::<Vec<_>>();
1270            let mut expected_buffer_rows = Vec::new();
1271            let mut expected_text = String::new();
1272            let input_text = wraps_snapshot.text();
1273            for (row, input_line) in input_text.split('\n').enumerate() {
1274                let row = row as u32;
1275                if row > 0 {
1276                    expected_text.push('\n');
1277                }
1278
1279                let buffer_row = input_buffer_rows[wraps_snapshot
1280                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1281                    .row as usize];
1282
1283                while let Some((_, block)) = sorted_blocks.peek() {
1284                    if block.position.row == row && block.disposition == BlockDisposition::Above {
1285                        let text = "\n".repeat(block.height as usize);
1286                        expected_text.push_str(&text);
1287                        for _ in 0..block.height {
1288                            expected_buffer_rows.push(None);
1289                        }
1290                        sorted_blocks.next();
1291                    } else {
1292                        break;
1293                    }
1294                }
1295
1296                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1297                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1298                expected_text.push_str(input_line);
1299
1300                while let Some((_, block)) = sorted_blocks.peek() {
1301                    if block.position.row == row && block.disposition == BlockDisposition::Below {
1302                        let text = "\n".repeat(block.height as usize);
1303                        expected_text.push_str(&text);
1304                        for _ in 0..block.height {
1305                            expected_buffer_rows.push(None);
1306                        }
1307                        sorted_blocks.next();
1308                    } else {
1309                        break;
1310                    }
1311                }
1312            }
1313
1314            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1315            let expected_row_count = expected_lines.len();
1316            for start_row in 0..expected_row_count {
1317                let expected_text = expected_lines[start_row..].join("\n");
1318                let actual_text = blocks_snapshot
1319                    .chunks(start_row as u32..expected_row_count as u32, None)
1320                    .map(|chunk| chunk.text)
1321                    .collect::<String>();
1322                assert_eq!(
1323                    actual_text, expected_text,
1324                    "incorrect text starting from row {}",
1325                    start_row
1326                );
1327                assert_eq!(
1328                    blocks_snapshot
1329                        .buffer_rows(start_row as u32)
1330                        .collect::<Vec<_>>(),
1331                    &expected_buffer_rows[start_row..]
1332                );
1333            }
1334
1335            let mut expected_longest_rows = Vec::new();
1336            let mut longest_line_len = -1_isize;
1337            for (row, line) in expected_lines.iter().enumerate() {
1338                let row = row as u32;
1339
1340                assert_eq!(
1341                    blocks_snapshot.line_len(row),
1342                    line.len() as u32,
1343                    "invalid line len for row {}",
1344                    row
1345                );
1346
1347                let line_char_count = line.chars().count() as isize;
1348                match line_char_count.cmp(&longest_line_len) {
1349                    Ordering::Less => {}
1350                    Ordering::Equal => expected_longest_rows.push(row),
1351                    Ordering::Greater => {
1352                        longest_line_len = line_char_count;
1353                        expected_longest_rows.clear();
1354                        expected_longest_rows.push(row);
1355                    }
1356                }
1357            }
1358
1359            let longest_row = blocks_snapshot.longest_row();
1360            assert!(
1361                expected_longest_rows.contains(&longest_row),
1362                "incorrect longest row {}. expected {:?} with length {}",
1363                longest_row,
1364                expected_longest_rows,
1365                longest_line_len,
1366            );
1367
1368            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1369                let wrap_point = WrapPoint::new(row, 0);
1370                let block_point = blocks_snapshot.to_block_point(wrap_point);
1371                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1372            }
1373
1374            let mut block_point = BlockPoint::new(0, 0);
1375            for c in expected_text.chars() {
1376                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1377                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1378                assert_eq!(
1379                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1380                    left_point
1381                );
1382                assert_eq!(
1383                    left_buffer_point,
1384                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1385                    "{:?} is not valid in buffer coordinates",
1386                    left_point
1387                );
1388
1389                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1390                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1391                assert_eq!(
1392                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1393                    right_point
1394                );
1395                assert_eq!(
1396                    right_buffer_point,
1397                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1398                    "{:?} is not valid in buffer coordinates",
1399                    right_point
1400                );
1401
1402                if c == '\n' {
1403                    block_point.0 += Point::new(1, 0);
1404                } else {
1405                    block_point.column += c.len_utf8() as u32;
1406                }
1407            }
1408        }
1409    }
1410
1411    impl BlockSnapshot {
1412        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1413            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1414        }
1415    }
1416}