block_map.rs

   1use super::wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot};
   2use crate::{Anchor, 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    pub line_number_x: f32,
  73}
  74
  75#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  76pub enum BlockDisposition {
  77    Above,
  78    Below,
  79}
  80
  81#[derive(Clone, Debug)]
  82struct Transform {
  83    summary: TransformSummary,
  84    block: Option<AlignedBlock>,
  85}
  86
  87#[derive(Clone, Debug)]
  88pub struct AlignedBlock {
  89    block: Arc<Block>,
  90    column: u32,
  91}
  92
  93#[derive(Clone, Debug, Default)]
  94struct TransformSummary {
  95    input_rows: u32,
  96    output_rows: u32,
  97}
  98
  99pub struct BlockChunks<'a> {
 100    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 101    input_chunks: wrap_map::WrapChunks<'a>,
 102    input_chunk: Chunk<'a>,
 103    output_row: u32,
 104    max_output_row: u32,
 105}
 106
 107pub struct BlockBufferRows<'a> {
 108    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 109    input_buffer_rows: wrap_map::WrapBufferRows<'a>,
 110    output_row: u32,
 111    started: bool,
 112}
 113
 114impl BlockMap {
 115    pub fn new(wrap_snapshot: WrapSnapshot) -> Self {
 116        Self {
 117            next_block_id: AtomicUsize::new(0),
 118            blocks: Vec::new(),
 119            transforms: Mutex::new(SumTree::from_item(
 120                Transform::isomorphic(wrap_snapshot.text_summary().lines.row + 1),
 121                &(),
 122            )),
 123            wrap_snapshot: Mutex::new(wrap_snapshot),
 124        }
 125    }
 126
 127    pub fn read(&self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockSnapshot {
 128        self.sync(&wrap_snapshot, edits);
 129        *self.wrap_snapshot.lock() = wrap_snapshot.clone();
 130        BlockSnapshot {
 131            wrap_snapshot,
 132            transforms: self.transforms.lock().clone(),
 133        }
 134    }
 135
 136    pub fn write(&mut self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockMapWriter {
 137        self.sync(&wrap_snapshot, edits);
 138        *self.wrap_snapshot.lock() = wrap_snapshot;
 139        BlockMapWriter(self)
 140    }
 141
 142    fn sync(&self, wrap_snapshot: &WrapSnapshot, edits: Vec<WrapEdit>) {
 143        if edits.is_empty() {
 144            return;
 145        }
 146
 147        let buffer = wrap_snapshot.buffer_snapshot();
 148        let mut transforms = self.transforms.lock();
 149        let mut new_transforms = SumTree::new();
 150        let old_row_count = transforms.summary().input_rows;
 151        let new_row_count = wrap_snapshot.max_point().row() + 1;
 152        let mut cursor = transforms.cursor::<WrapRow>();
 153        let mut last_block_ix = 0;
 154        let mut blocks_in_edit = Vec::new();
 155        let mut edits = edits.into_iter().peekable();
 156
 157        while let Some(edit) = edits.next() {
 158            // Preserve any old transforms that precede this edit.
 159            let old_start = WrapRow(edit.old.start);
 160            let new_start = WrapRow(edit.new.start);
 161            new_transforms.push_tree(cursor.slice(&old_start, Bias::Left, &()), &());
 162            if let Some(transform) = cursor.item() {
 163                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 164                    new_transforms.push(transform.clone(), &());
 165                    cursor.next(&());
 166                    while let Some(transform) = cursor.item() {
 167                        if transform
 168                            .block
 169                            .as_ref()
 170                            .map_or(false, |b| b.disposition.is_below())
 171                        {
 172                            new_transforms.push(transform.clone(), &());
 173                            cursor.next(&());
 174                        } else {
 175                            break;
 176                        }
 177                    }
 178                }
 179            }
 180
 181            // Preserve any portion of an old transform that precedes this edit.
 182            let extent_before_edit = old_start.0 - cursor.start().0;
 183            push_isomorphic(&mut new_transforms, extent_before_edit);
 184
 185            // Skip over any old transforms that intersect this edit.
 186            let mut old_end = WrapRow(edit.old.end);
 187            let mut new_end = WrapRow(edit.new.end);
 188            cursor.seek(&old_end, Bias::Left, &());
 189            cursor.next(&());
 190            if old_end == *cursor.start() {
 191                while let Some(transform) = cursor.item() {
 192                    if transform
 193                        .block
 194                        .as_ref()
 195                        .map_or(false, |b| b.disposition.is_below())
 196                    {
 197                        cursor.next(&());
 198                    } else {
 199                        break;
 200                    }
 201                }
 202            }
 203
 204            // Combine this edit with any subsequent edits that intersect the same transform.
 205            while let Some(next_edit) = edits.peek() {
 206                if next_edit.old.start <= cursor.start().0 {
 207                    old_end = WrapRow(next_edit.old.end);
 208                    new_end = WrapRow(next_edit.new.end);
 209                    cursor.seek(&old_end, Bias::Left, &());
 210                    cursor.next(&());
 211                    if old_end == *cursor.start() {
 212                        while let Some(transform) = cursor.item() {
 213                            if transform
 214                                .block
 215                                .as_ref()
 216                                .map_or(false, |b| b.disposition.is_below())
 217                            {
 218                                cursor.next(&());
 219                            } else {
 220                                break;
 221                            }
 222                        }
 223                    }
 224                    edits.next();
 225                } else {
 226                    break;
 227                }
 228            }
 229
 230            // Find the blocks within this edited region.
 231            let new_buffer_start =
 232                wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 233            let start_anchor = buffer.anchor_before(new_buffer_start);
 234            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 235                probe
 236                    .position
 237                    .cmp(&start_anchor, &buffer)
 238                    .unwrap()
 239                    .then(Ordering::Greater)
 240            }) {
 241                Ok(ix) | Err(ix) => last_block_ix + ix,
 242            };
 243
 244            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 245                self.blocks.len()
 246            } else {
 247                let new_buffer_end =
 248                    wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 249                let end_anchor = buffer.anchor_before(new_buffer_end);
 250                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 251                    probe
 252                        .position
 253                        .cmp(&end_anchor, &buffer)
 254                        .unwrap()
 255                        .then(Ordering::Greater)
 256                }) {
 257                    Ok(ix) | Err(ix) => start_block_ix + ix,
 258                }
 259            };
 260            last_block_ix = end_block_ix;
 261
 262            debug_assert!(blocks_in_edit.is_empty());
 263            blocks_in_edit.extend(
 264                self.blocks[start_block_ix..end_block_ix]
 265                    .iter()
 266                    .map(|block| {
 267                        let mut position = block.position.to_point(&buffer);
 268                        let column = wrap_snapshot.from_point(position, Bias::Left).column();
 269                        match block.disposition {
 270                            BlockDisposition::Above => position.column = 0,
 271                            BlockDisposition::Below => {
 272                                position.column = buffer.line_len(position.row)
 273                            }
 274                        }
 275                        let position = wrap_snapshot.from_point(position, Bias::Left);
 276                        (position.row(), column, block.clone())
 277                    }),
 278            );
 279            blocks_in_edit.sort_by_key(|(row, _, block)| (*row, block.disposition, block.id));
 280
 281            // For each of these blocks, insert a new isomorphic transform preceding the block,
 282            // and then insert the block itself.
 283            for (block_row, column, block) in blocks_in_edit.drain(..) {
 284                let insertion_row = match block.disposition {
 285                    BlockDisposition::Above => block_row,
 286                    BlockDisposition::Below => block_row + 1,
 287                };
 288                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 289                push_isomorphic(&mut new_transforms, extent_before_block);
 290                new_transforms.push(Transform::block(block, column), &());
 291            }
 292
 293            old_end = WrapRow(old_end.0.min(old_row_count));
 294            new_end = WrapRow(new_end.0.min(new_row_count));
 295
 296            // Insert an isomorphic transform after the final block.
 297            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 298            push_isomorphic(&mut new_transforms, extent_after_last_block);
 299
 300            // Preserve any portion of the old transform after this edit.
 301            let extent_after_edit = cursor.start().0 - old_end.0;
 302            push_isomorphic(&mut new_transforms, extent_after_edit);
 303        }
 304
 305        new_transforms.push_tree(cursor.suffix(&()), &());
 306        debug_assert_eq!(
 307            new_transforms.summary().input_rows,
 308            wrap_snapshot.max_point().row() + 1
 309        );
 310
 311        drop(cursor);
 312        *transforms = new_transforms;
 313    }
 314
 315    pub fn replace(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 316        for block in &self.blocks {
 317            if let Some(render) = renderers.remove(&block.id) {
 318                *block.render.lock() = render;
 319            }
 320        }
 321    }
 322}
 323
 324fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 325    if rows == 0 {
 326        return;
 327    }
 328
 329    let mut extent = Some(rows);
 330    tree.update_last(
 331        |last_transform| {
 332            if last_transform.is_isomorphic() {
 333                let extent = extent.take().unwrap();
 334                last_transform.summary.input_rows += extent;
 335                last_transform.summary.output_rows += extent;
 336            }
 337        },
 338        &(),
 339    );
 340    if let Some(extent) = extent {
 341        tree.push(Transform::isomorphic(extent), &());
 342    }
 343}
 344
 345impl BlockPoint {
 346    pub fn new(row: u32, column: u32) -> Self {
 347        Self(Point::new(row, column))
 348    }
 349}
 350
 351impl Deref for BlockPoint {
 352    type Target = Point;
 353
 354    fn deref(&self) -> &Self::Target {
 355        &self.0
 356    }
 357}
 358
 359impl std::ops::DerefMut for BlockPoint {
 360    fn deref_mut(&mut self) -> &mut Self::Target {
 361        &mut self.0
 362    }
 363}
 364
 365impl<'a> BlockMapWriter<'a> {
 366    pub fn insert(
 367        &mut self,
 368        blocks: impl IntoIterator<Item = BlockProperties<Anchor>>,
 369    ) -> Vec<BlockId> {
 370        let mut ids = Vec::new();
 371        let mut edits = Vec::<Edit<u32>>::new();
 372        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 373        let buffer = wrap_snapshot.buffer_snapshot();
 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 = block.position;
 380            let point = position.to_point(&buffer);
 381            let wrap_row = wrap_snapshot
 382                .from_point(Point::new(point.row, 0), Bias::Left)
 383                .row();
 384            let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 385            let end_row = wrap_snapshot
 386                .next_row_boundary(WrapPoint::new(wrap_row, 0))
 387                .unwrap_or(wrap_snapshot.max_point().row() + 1);
 388
 389            let block_ix = match self
 390                .0
 391                .blocks
 392                .binary_search_by(|probe| probe.position.cmp(&position, &buffer).unwrap())
 393            {
 394                Ok(ix) | Err(ix) => ix,
 395            };
 396            self.0.blocks.insert(
 397                block_ix,
 398                Arc::new(Block {
 399                    id,
 400                    position,
 401                    height: block.height,
 402                    render: Mutex::new(block.render),
 403                    disposition: block.disposition,
 404                }),
 405            );
 406
 407            if let Err(edit_ix) = edits.binary_search_by_key(&start_row, |edit| edit.old.start) {
 408                edits.insert(
 409                    edit_ix,
 410                    Edit {
 411                        old: start_row..end_row,
 412                        new: start_row..end_row,
 413                    },
 414                );
 415            }
 416        }
 417
 418        self.0.sync(wrap_snapshot, edits);
 419        ids
 420    }
 421
 422    pub fn remove(&mut self, block_ids: HashSet<BlockId>) {
 423        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 424        let buffer = wrap_snapshot.buffer_snapshot();
 425        let mut edits = Vec::new();
 426        let mut last_block_buffer_row = None;
 427        self.0.blocks.retain(|block| {
 428            if block_ids.contains(&block.id) {
 429                let buffer_row = block.position.to_point(&buffer).row;
 430                if last_block_buffer_row != Some(buffer_row) {
 431                    last_block_buffer_row = Some(buffer_row);
 432                    let wrap_row = wrap_snapshot
 433                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 434                        .row();
 435                    let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 436                    let end_row = wrap_snapshot
 437                        .next_row_boundary(WrapPoint::new(wrap_row, 0))
 438                        .unwrap_or(wrap_snapshot.max_point().row() + 1);
 439                    edits.push(Edit {
 440                        old: start_row..end_row,
 441                        new: start_row..end_row,
 442                    })
 443                }
 444                false
 445            } else {
 446                true
 447            }
 448        });
 449        self.0.sync(wrap_snapshot, edits);
 450    }
 451}
 452
 453impl BlockSnapshot {
 454    #[cfg(test)]
 455    pub fn text(&self) -> String {
 456        self.chunks(0..self.transforms.summary().output_rows, None)
 457            .map(|chunk| chunk.text)
 458            .collect()
 459    }
 460
 461    pub fn chunks<'a>(
 462        &'a self,
 463        rows: Range<u32>,
 464        theme: Option<&'a SyntaxTheme>,
 465    ) -> BlockChunks<'a> {
 466        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 467        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 468        let input_end = {
 469            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 470            let overshoot = if cursor
 471                .item()
 472                .map_or(false, |transform| transform.is_isomorphic())
 473            {
 474                rows.end - cursor.start().0 .0
 475            } else {
 476                0
 477            };
 478            cursor.start().1 .0 + overshoot
 479        };
 480        let input_start = {
 481            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 482            let overshoot = if cursor
 483                .item()
 484                .map_or(false, |transform| transform.is_isomorphic())
 485            {
 486                rows.start - cursor.start().0 .0
 487            } else {
 488                0
 489            };
 490            cursor.start().1 .0 + overshoot
 491        };
 492        BlockChunks {
 493            input_chunks: self.wrap_snapshot.chunks(input_start..input_end, theme),
 494            input_chunk: Default::default(),
 495            transforms: cursor,
 496            output_row: rows.start,
 497            max_output_row,
 498        }
 499    }
 500
 501    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> BlockBufferRows<'a> {
 502        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 503        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 504        let (output_start, input_start) = cursor.start();
 505        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 506            start_row - output_start.0
 507        } else {
 508            0
 509        };
 510        let input_start_row = input_start.0 + overshoot;
 511        BlockBufferRows {
 512            transforms: cursor,
 513            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 514            output_row: start_row,
 515            started: false,
 516        }
 517    }
 518
 519    pub fn blocks_in_range<'a>(
 520        &'a self,
 521        rows: Range<u32>,
 522    ) -> impl Iterator<Item = (u32, &'a AlignedBlock)> {
 523        let mut cursor = self.transforms.cursor::<BlockRow>();
 524        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 525        std::iter::from_fn(move || {
 526            while let Some(transform) = cursor.item() {
 527                let start_row = cursor.start().0;
 528                if start_row >= rows.end {
 529                    break;
 530                }
 531                if let Some(block) = &transform.block {
 532                    cursor.next(&());
 533                    return Some((start_row, block));
 534                } else {
 535                    cursor.next(&());
 536                }
 537            }
 538            None
 539        })
 540    }
 541
 542    pub fn max_point(&self) -> BlockPoint {
 543        let row = self.transforms.summary().output_rows - 1;
 544        BlockPoint::new(row, self.line_len(row))
 545    }
 546
 547    pub fn longest_row(&self) -> u32 {
 548        let input_row = self.wrap_snapshot.longest_row();
 549        self.to_block_point(WrapPoint::new(input_row, 0)).row
 550    }
 551
 552    pub fn line_len(&self, row: u32) -> u32 {
 553        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 554        cursor.seek(&BlockRow(row), Bias::Right, &());
 555        if let Some(transform) = cursor.item() {
 556            let (output_start, input_start) = cursor.start();
 557            let overshoot = row - output_start.0;
 558            if transform.block.is_some() {
 559                0
 560            } else {
 561                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 562            }
 563        } else {
 564            panic!("row out of range");
 565        }
 566    }
 567
 568    pub fn is_block_line(&self, row: u32) -> bool {
 569        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 570        cursor.seek(&BlockRow(row), Bias::Right, &());
 571        cursor.item().map_or(false, |t| t.block.is_some())
 572    }
 573
 574    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 575        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 576        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 577
 578        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 579        let mut search_left =
 580            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 581        let mut reversed = false;
 582
 583        loop {
 584            if let Some(transform) = cursor.item() {
 585                if transform.is_isomorphic() {
 586                    let (output_start_row, input_start_row) = cursor.start();
 587                    let (output_end_row, input_end_row) = cursor.end(&());
 588                    let output_start = Point::new(output_start_row.0, 0);
 589                    let input_start = Point::new(input_start_row.0, 0);
 590                    let input_end = Point::new(input_end_row.0, 0);
 591                    let input_point = if point.row >= output_end_row.0 {
 592                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 593                        self.wrap_snapshot
 594                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 595                    } else {
 596                        let output_overshoot = point.0.saturating_sub(output_start);
 597                        self.wrap_snapshot
 598                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 599                    };
 600
 601                    if (input_start..input_end).contains(&input_point.0) {
 602                        let input_overshoot = input_point.0.saturating_sub(input_start);
 603                        return BlockPoint(output_start + input_overshoot);
 604                    }
 605                }
 606
 607                if search_left {
 608                    cursor.prev(&());
 609                } else {
 610                    cursor.next(&());
 611                }
 612            } else if reversed {
 613                return self.max_point();
 614            } else {
 615                reversed = true;
 616                search_left = !search_left;
 617                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 618            }
 619        }
 620    }
 621
 622    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 623        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 624        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 625        if let Some(transform) = cursor.item() {
 626            debug_assert!(transform.is_isomorphic());
 627        } else {
 628            return self.max_point();
 629        }
 630
 631        let (input_start_row, output_start_row) = cursor.start();
 632        let input_start = Point::new(input_start_row.0, 0);
 633        let output_start = Point::new(output_start_row.0, 0);
 634        let input_overshoot = wrap_point.0 - input_start;
 635        BlockPoint(output_start + input_overshoot)
 636    }
 637
 638    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 639        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 640        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 641        if let Some(transform) = cursor.item() {
 642            match transform.block.as_ref().map(|b| b.disposition) {
 643                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 644                Some(BlockDisposition::Below) => {
 645                    let wrap_row = cursor.start().1 .0 - 1;
 646                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 647                }
 648                None => {
 649                    let overshoot = block_point.row - cursor.start().0 .0;
 650                    let wrap_row = cursor.start().1 .0 + overshoot;
 651                    WrapPoint::new(wrap_row, block_point.column)
 652                }
 653            }
 654        } else {
 655            self.wrap_snapshot.max_point()
 656        }
 657    }
 658}
 659
 660impl Transform {
 661    fn isomorphic(rows: u32) -> Self {
 662        Self {
 663            summary: TransformSummary {
 664                input_rows: rows,
 665                output_rows: rows,
 666            },
 667            block: None,
 668        }
 669    }
 670
 671    fn block(block: Arc<Block>, column: u32) -> Self {
 672        Self {
 673            summary: TransformSummary {
 674                input_rows: 0,
 675                output_rows: block.height as u32,
 676            },
 677            block: Some(AlignedBlock { block, column }),
 678        }
 679    }
 680
 681    fn is_isomorphic(&self) -> bool {
 682        self.block.is_none()
 683    }
 684}
 685
 686impl<'a> Iterator for BlockChunks<'a> {
 687    type Item = Chunk<'a>;
 688
 689    fn next(&mut self) -> Option<Self::Item> {
 690        if self.output_row >= self.max_output_row {
 691            return None;
 692        }
 693
 694        let transform = self.transforms.item()?;
 695        if transform.block.is_some() {
 696            let block_start = self.transforms.start().0 .0;
 697            let mut block_end = self.transforms.end(&()).0 .0;
 698            self.transforms.next(&());
 699            if self.transforms.item().is_none() {
 700                block_end -= 1;
 701            }
 702
 703            let start_in_block = self.output_row - block_start;
 704            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 705            let line_count = end_in_block - start_in_block;
 706            self.output_row += line_count;
 707
 708            return Some(Chunk {
 709                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 710                highlight_style: None,
 711                diagnostic: None,
 712            });
 713        }
 714
 715        if self.input_chunk.text.is_empty() {
 716            if let Some(input_chunk) = self.input_chunks.next() {
 717                self.input_chunk = input_chunk;
 718            } else {
 719                self.output_row += 1;
 720                if self.output_row < self.max_output_row {
 721                    self.transforms.next(&());
 722                    return Some(Chunk {
 723                        text: "\n",
 724                        ..Default::default()
 725                    });
 726                } else {
 727                    return None;
 728                }
 729            }
 730        }
 731
 732        let transform_end = self.transforms.end(&()).0 .0;
 733        let (prefix_rows, prefix_bytes) =
 734            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 735        self.output_row += prefix_rows;
 736        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 737        self.input_chunk.text = suffix;
 738        if self.output_row == transform_end {
 739            self.transforms.next(&());
 740        }
 741
 742        Some(Chunk {
 743            text: prefix,
 744            ..self.input_chunk
 745        })
 746    }
 747}
 748
 749impl<'a> Iterator for BlockBufferRows<'a> {
 750    type Item = Option<u32>;
 751
 752    fn next(&mut self) -> Option<Self::Item> {
 753        if self.started {
 754            self.output_row += 1;
 755        } else {
 756            self.started = true;
 757        }
 758
 759        if self.output_row >= self.transforms.end(&()).0 .0 {
 760            self.transforms.next(&());
 761        }
 762
 763        let transform = self.transforms.item()?;
 764        if transform.block.is_some() {
 765            Some(None)
 766        } else {
 767            Some(self.input_buffer_rows.next().unwrap())
 768        }
 769    }
 770}
 771
 772impl sum_tree::Item for Transform {
 773    type Summary = TransformSummary;
 774
 775    fn summary(&self) -> Self::Summary {
 776        self.summary.clone()
 777    }
 778}
 779
 780impl sum_tree::Summary for TransformSummary {
 781    type Context = ();
 782
 783    fn add_summary(&mut self, summary: &Self, _: &()) {
 784        self.input_rows += summary.input_rows;
 785        self.output_rows += summary.output_rows;
 786    }
 787}
 788
 789impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 790    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 791        self.0 += summary.input_rows;
 792    }
 793}
 794
 795impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 796    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 797        self.0 += summary.output_rows;
 798    }
 799}
 800
 801impl BlockDisposition {
 802    fn is_below(&self) -> bool {
 803        matches!(self, BlockDisposition::Below)
 804    }
 805}
 806
 807impl AlignedBlock {
 808    pub fn height(&self) -> u32 {
 809        self.height as u32
 810    }
 811
 812    pub fn column(&self) -> u32 {
 813        self.column
 814    }
 815
 816    pub fn render(&self, cx: &BlockContext) -> ElementBox {
 817        self.render.lock()(cx)
 818    }
 819
 820    pub fn position(&self) -> &Anchor {
 821        &self.block.position
 822    }
 823}
 824
 825impl Deref for AlignedBlock {
 826    type Target = Block;
 827
 828    fn deref(&self) -> &Self::Target {
 829        self.block.as_ref()
 830    }
 831}
 832
 833impl<'a> Deref for BlockContext<'a> {
 834    type Target = AppContext;
 835
 836    fn deref(&self) -> &Self::Target {
 837        &self.cx
 838    }
 839}
 840
 841impl Debug for Block {
 842    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 843        f.debug_struct("Block")
 844            .field("id", &self.id)
 845            .field("position", &self.position)
 846            .field("disposition", &self.disposition)
 847            .finish()
 848    }
 849}
 850
 851// Count the number of bytes prior to a target point. If the string doesn't contain the target
 852// point, return its total extent. Otherwise return the target point itself.
 853fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 854    let mut row = 0;
 855    let mut offset = 0;
 856    for (ix, line) in s.split('\n').enumerate() {
 857        if ix > 0 {
 858            row += 1;
 859            offset += 1;
 860        }
 861        if row >= target {
 862            break;
 863        }
 864        offset += line.len() as usize;
 865    }
 866    (row, offset)
 867}
 868
 869#[cfg(test)]
 870mod tests {
 871    use super::*;
 872    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 873    use crate::multi_buffer::MultiBuffer;
 874    use gpui::{elements::Empty, Element};
 875    use rand::prelude::*;
 876    use std::env;
 877    use text::RandomCharIter;
 878
 879    #[gpui::test]
 880    fn test_offset_for_row() {
 881        assert_eq!(offset_for_row("", 0), (0, 0));
 882        assert_eq!(offset_for_row("", 1), (0, 0));
 883        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 884        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 885        assert_eq!(offset_for_row("\n", 0), (0, 0));
 886        assert_eq!(offset_for_row("\n", 1), (1, 1));
 887        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 888        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 889        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 890        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 891    }
 892
 893    #[gpui::test]
 894    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 895        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 896        let font_id = cx
 897            .font_cache()
 898            .select_font(family_id, &Default::default())
 899            .unwrap();
 900
 901        let text = "aaa\nbbb\nccc\nddd";
 902
 903        let buffer = MultiBuffer::build_simple(text, cx);
 904        let buffer_snapshot = buffer.read(cx).snapshot(cx);
 905        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
 906        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
 907        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 908        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 909        let mut block_map = BlockMap::new(wraps_snapshot.clone());
 910
 911        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
 912        writer.insert(vec![
 913            BlockProperties {
 914                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
 915                height: 1,
 916                disposition: BlockDisposition::Above,
 917                render: Arc::new(|_| Empty::new().named("block 1")),
 918            },
 919            BlockProperties {
 920                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
 921                height: 2,
 922                disposition: BlockDisposition::Above,
 923                render: Arc::new(|_| Empty::new().named("block 2")),
 924            },
 925            BlockProperties {
 926                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
 927                height: 3,
 928                disposition: BlockDisposition::Below,
 929                render: Arc::new(|_| Empty::new().named("block 3")),
 930            },
 931        ]);
 932
 933        let snapshot = block_map.read(wraps_snapshot, vec![]);
 934        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
 935
 936        let blocks = snapshot
 937            .blocks_in_range(0..8)
 938            .map(|(start_row, block)| {
 939                (
 940                    start_row..start_row + block.height(),
 941                    block.column(),
 942                    block
 943                        .render(&BlockContext { cx, anchor_x: 0., line_number_x: 0., })
 944                        .name()
 945                        .unwrap()
 946                        .to_string(),
 947                )
 948            })
 949            .collect::<Vec<_>>();
 950        assert_eq!(
 951            blocks,
 952            &[
 953                (1..2, 0, "block 1".to_string()),
 954                (2..4, 2, "block 2".to_string()),
 955                (7..10, 3, "block 3".to_string()),
 956            ]
 957        );
 958
 959        assert_eq!(
 960            snapshot.to_block_point(WrapPoint::new(0, 3)),
 961            BlockPoint::new(0, 3)
 962        );
 963        assert_eq!(
 964            snapshot.to_block_point(WrapPoint::new(1, 0)),
 965            BlockPoint::new(4, 0)
 966        );
 967        assert_eq!(
 968            snapshot.to_block_point(WrapPoint::new(3, 3)),
 969            BlockPoint::new(6, 3)
 970        );
 971
 972        assert_eq!(
 973            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
 974            WrapPoint::new(0, 3)
 975        );
 976        assert_eq!(
 977            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
 978            WrapPoint::new(1, 0)
 979        );
 980        assert_eq!(
 981            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
 982            WrapPoint::new(1, 0)
 983        );
 984        assert_eq!(
 985            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
 986            WrapPoint::new(3, 3)
 987        );
 988
 989        assert_eq!(
 990            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
 991            BlockPoint::new(0, 3)
 992        );
 993        assert_eq!(
 994            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
 995            BlockPoint::new(4, 0)
 996        );
 997        assert_eq!(
 998            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
 999            BlockPoint::new(0, 3)
1000        );
1001        assert_eq!(
1002            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1003            BlockPoint::new(4, 0)
1004        );
1005        assert_eq!(
1006            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1007            BlockPoint::new(4, 0)
1008        );
1009        assert_eq!(
1010            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1011            BlockPoint::new(4, 0)
1012        );
1013        assert_eq!(
1014            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1015            BlockPoint::new(6, 3)
1016        );
1017        assert_eq!(
1018            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1019            BlockPoint::new(6, 3)
1020        );
1021        assert_eq!(
1022            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1023            BlockPoint::new(6, 3)
1024        );
1025        assert_eq!(
1026            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1027            BlockPoint::new(6, 3)
1028        );
1029
1030        assert_eq!(
1031            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1032            &[
1033                Some(0),
1034                None,
1035                None,
1036                None,
1037                Some(1),
1038                Some(2),
1039                Some(3),
1040                None,
1041                None,
1042                None
1043            ]
1044        );
1045
1046        // Insert a line break, separating two block decorations into separate lines.
1047        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1048            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
1049            buffer.snapshot(cx)
1050        });
1051
1052        let (folds_snapshot, fold_edits) =
1053            fold_map.read(buffer_snapshot, subscription.consume().into_inner());
1054        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1055        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1056            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1057        });
1058        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1059        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1060    }
1061
1062    #[gpui::test]
1063    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1064        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1065        let font_id = cx
1066            .font_cache()
1067            .select_font(family_id, &Default::default())
1068            .unwrap();
1069
1070        let text = "one two three\nfour five six\nseven eight";
1071
1072        let buffer = MultiBuffer::build_simple(text, cx);
1073        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1074        let (_, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
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: buffer_snapshot.anchor_after(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: buffer_snapshot.anchor_after(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}