block_map.rs

   1use super::wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot};
   2use crate::{Anchor, ToOffset, ToPoint as _};
   3use gpui::{AppContext, ElementBox};
   4use language::Chunk;
   5use parking_lot::Mutex;
   6use std::{
   7    cmp::{self, Ordering},
   8    collections::{HashMap, HashSet},
   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_start = wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 231            let start_anchor = buffer.anchor_before(new_start);
 232            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 233                probe
 234                    .position
 235                    .cmp(&start_anchor, &buffer)
 236                    .unwrap()
 237                    .then(Ordering::Greater)
 238            }) {
 239                Ok(ix) | Err(ix) => last_block_ix + ix,
 240            };
 241            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 242                self.blocks.len()
 243            } else {
 244                let new_end = wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 245                let end_anchor = buffer.anchor_before(new_end);
 246                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 247                    probe
 248                        .position
 249                        .cmp(&end_anchor, &buffer)
 250                        .unwrap()
 251                        .then(Ordering::Greater)
 252                }) {
 253                    Ok(ix) | Err(ix) => start_block_ix + ix,
 254                }
 255            };
 256            last_block_ix = end_block_ix;
 257            blocks_in_edit.clear();
 258            blocks_in_edit.extend(
 259                self.blocks[start_block_ix..end_block_ix]
 260                    .iter()
 261                    .map(|block| {
 262                        let mut position = block.position.to_point(&buffer);
 263                        let column = wrap_snapshot.from_point(position, Bias::Left).column();
 264                        match block.disposition {
 265                            BlockDisposition::Above => position.column = 0,
 266                            BlockDisposition::Below => {
 267                                position.column = buffer.line_len(position.row)
 268                            }
 269                        }
 270                        let position = wrap_snapshot.from_point(position, Bias::Left);
 271                        (position.row(), column, block)
 272                    }),
 273            );
 274            blocks_in_edit
 275                .sort_unstable_by_key(|(row, _, block)| (*row, block.disposition, block.id));
 276
 277            // For each of these blocks, insert a new isomorphic transform preceding the block,
 278            // and then insert the block itself.
 279            for (block_row, column, block) in blocks_in_edit.iter().copied() {
 280                let insertion_row = match block.disposition {
 281                    BlockDisposition::Above => block_row,
 282                    BlockDisposition::Below => block_row + 1,
 283                };
 284                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 285                push_isomorphic(&mut new_transforms, extent_before_block);
 286                new_transforms.push(Transform::block(block.clone(), column), &());
 287            }
 288
 289            old_end = WrapRow(old_end.0.min(old_row_count));
 290            new_end = WrapRow(new_end.0.min(new_row_count));
 291
 292            // Insert an isomorphic transform after the final block.
 293            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 294            push_isomorphic(&mut new_transforms, extent_after_last_block);
 295
 296            // Preserve any portion of the old transform after this edit.
 297            let extent_after_edit = cursor.start().0 - old_end.0;
 298            push_isomorphic(&mut new_transforms, extent_after_edit);
 299        }
 300
 301        new_transforms.push_tree(cursor.suffix(&()), &());
 302        debug_assert_eq!(
 303            new_transforms.summary().input_rows,
 304            wrap_snapshot.max_point().row() + 1
 305        );
 306
 307        drop(cursor);
 308        *transforms = new_transforms;
 309    }
 310
 311    pub fn replace(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 312        for block in &self.blocks {
 313            if let Some(render) = renderers.remove(&block.id) {
 314                *block.render.lock() = render;
 315            }
 316        }
 317    }
 318}
 319
 320fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 321    if rows == 0 {
 322        return;
 323    }
 324
 325    let mut extent = Some(rows);
 326    tree.update_last(
 327        |last_transform| {
 328            if last_transform.is_isomorphic() {
 329                let extent = extent.take().unwrap();
 330                last_transform.summary.input_rows += extent;
 331                last_transform.summary.output_rows += extent;
 332            }
 333        },
 334        &(),
 335    );
 336    if let Some(extent) = extent {
 337        tree.push(Transform::isomorphic(extent), &());
 338    }
 339}
 340
 341impl BlockPoint {
 342    pub fn new(row: u32, column: u32) -> Self {
 343        Self(Point::new(row, column))
 344    }
 345}
 346
 347impl Deref for BlockPoint {
 348    type Target = Point;
 349
 350    fn deref(&self) -> &Self::Target {
 351        &self.0
 352    }
 353}
 354
 355impl std::ops::DerefMut for BlockPoint {
 356    fn deref_mut(&mut self) -> &mut Self::Target {
 357        &mut self.0
 358    }
 359}
 360
 361impl<'a> BlockMapWriter<'a> {
 362    pub fn insert<P>(
 363        &mut self,
 364        blocks: impl IntoIterator<Item = BlockProperties<P>>,
 365    ) -> Vec<BlockId>
 366    where
 367        P: ToOffset + Clone,
 368    {
 369        let mut ids = Vec::new();
 370        let mut edits = Vec::<Edit<u32>>::new();
 371        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 372        let buffer = wrap_snapshot.buffer_snapshot();
 373
 374        for block in blocks {
 375            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 376            ids.push(id);
 377
 378            let position = buffer.anchor_after(block.position);
 379            let point = position.to_point(&buffer);
 380            let start_row = wrap_snapshot
 381                .from_point(Point::new(point.row, 0), Bias::Left)
 382                .row();
 383            let end_row = if point.row == buffer.max_point().row {
 384                wrap_snapshot.max_point().row() + 1
 385            } else {
 386                wrap_snapshot
 387                    .from_point(Point::new(point.row + 1, 0), Bias::Left)
 388                    .row()
 389            };
 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 start_row = wrap_snapshot
 435                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 436                        .row();
 437                    let end_row = wrap_snapshot
 438                        .from_point(
 439                            Point::new(buffer_row, buffer.line_len(buffer_row)),
 440                            Bias::Left,
 441                        )
 442                        .row()
 443                        + 1;
 444                    edits.push(Edit {
 445                        old: start_row..end_row,
 446                        new: start_row..end_row,
 447                    })
 448                }
 449                false
 450            } else {
 451                true
 452            }
 453        });
 454        self.0.sync(wrap_snapshot, edits);
 455    }
 456}
 457
 458impl BlockSnapshot {
 459    #[cfg(test)]
 460    fn text(&mut self) -> String {
 461        self.chunks(0..self.transforms.summary().output_rows, None)
 462            .map(|chunk| chunk.text)
 463            .collect()
 464    }
 465
 466    pub fn chunks<'a>(
 467        &'a self,
 468        rows: Range<u32>,
 469        theme: Option<&'a SyntaxTheme>,
 470    ) -> BlockChunks<'a> {
 471        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 472        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 473        let input_end = {
 474            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 475            let overshoot = if cursor
 476                .item()
 477                .map_or(false, |transform| transform.is_isomorphic())
 478            {
 479                rows.end - cursor.start().0 .0
 480            } else {
 481                0
 482            };
 483            cursor.start().1 .0 + overshoot
 484        };
 485        let input_start = {
 486            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 487            let overshoot = if cursor
 488                .item()
 489                .map_or(false, |transform| transform.is_isomorphic())
 490            {
 491                rows.start - cursor.start().0 .0
 492            } else {
 493                0
 494            };
 495            cursor.start().1 .0 + overshoot
 496        };
 497        BlockChunks {
 498            input_chunks: self.wrap_snapshot.chunks(input_start..input_end, theme),
 499            input_chunk: Default::default(),
 500            transforms: cursor,
 501            output_row: rows.start,
 502            max_output_row,
 503        }
 504    }
 505
 506    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> BlockBufferRows<'a> {
 507        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 508        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 509        let (output_start, input_start) = cursor.start();
 510        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 511            start_row - output_start.0
 512        } else {
 513            0
 514        };
 515        let input_start_row = input_start.0 + overshoot;
 516        BlockBufferRows {
 517            transforms: cursor,
 518            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 519            output_row: start_row,
 520            started: false,
 521        }
 522    }
 523
 524    pub fn blocks_in_range<'a>(
 525        &'a self,
 526        rows: Range<u32>,
 527    ) -> impl Iterator<Item = (u32, &'a AlignedBlock)> {
 528        let mut cursor = self.transforms.cursor::<BlockRow>();
 529        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 530        std::iter::from_fn(move || {
 531            while let Some(transform) = cursor.item() {
 532                let start_row = cursor.start().0;
 533                if start_row >= rows.end {
 534                    break;
 535                }
 536                if let Some(block) = &transform.block {
 537                    cursor.next(&());
 538                    return Some((start_row, block));
 539                } else {
 540                    cursor.next(&());
 541                }
 542            }
 543            None
 544        })
 545    }
 546
 547    pub fn max_point(&self) -> BlockPoint {
 548        let row = self.transforms.summary().output_rows - 1;
 549        BlockPoint::new(row, self.line_len(row))
 550    }
 551
 552    pub fn longest_row(&self) -> u32 {
 553        let input_row = self.wrap_snapshot.longest_row();
 554        self.to_block_point(WrapPoint::new(input_row, 0)).row
 555    }
 556
 557    pub fn line_len(&self, row: u32) -> u32 {
 558        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 559        cursor.seek(&BlockRow(row), Bias::Right, &());
 560        if let Some(transform) = cursor.item() {
 561            let (output_start, input_start) = cursor.start();
 562            let overshoot = row - output_start.0;
 563            if transform.block.is_some() {
 564                0
 565            } else {
 566                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 567            }
 568        } else {
 569            panic!("row out of range");
 570        }
 571    }
 572
 573    pub fn is_block_line(&self, row: u32) -> bool {
 574        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 575        cursor.seek(&BlockRow(row), Bias::Right, &());
 576        cursor.item().map_or(false, |t| t.block.is_some())
 577    }
 578
 579    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 580        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 581        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 582
 583        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 584        let mut search_left =
 585            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 586        let mut reversed = false;
 587
 588        loop {
 589            if let Some(transform) = cursor.item() {
 590                if transform.is_isomorphic() {
 591                    let (output_start_row, input_start_row) = cursor.start();
 592                    let (output_end_row, input_end_row) = cursor.end(&());
 593                    let output_start = Point::new(output_start_row.0, 0);
 594                    let input_start = Point::new(input_start_row.0, 0);
 595                    let input_end = Point::new(input_end_row.0, 0);
 596                    let input_point = if point.row >= output_end_row.0 {
 597                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 598                        self.wrap_snapshot
 599                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 600                    } else {
 601                        let output_overshoot = point.0.saturating_sub(output_start);
 602                        self.wrap_snapshot
 603                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 604                    };
 605
 606                    if (input_start..input_end).contains(&input_point.0) {
 607                        let input_overshoot = input_point.0.saturating_sub(input_start);
 608                        return BlockPoint(output_start + input_overshoot);
 609                    }
 610                }
 611
 612                if search_left {
 613                    cursor.prev(&());
 614                } else {
 615                    cursor.next(&());
 616                }
 617            } else if reversed {
 618                return self.max_point();
 619            } else {
 620                reversed = true;
 621                search_left = !search_left;
 622                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 623            }
 624        }
 625    }
 626
 627    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 628        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 629        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 630        if let Some(transform) = cursor.item() {
 631            debug_assert!(transform.is_isomorphic());
 632        } else {
 633            return self.max_point();
 634        }
 635
 636        let (input_start_row, output_start_row) = cursor.start();
 637        let input_start = Point::new(input_start_row.0, 0);
 638        let output_start = Point::new(output_start_row.0, 0);
 639        let input_overshoot = wrap_point.0 - input_start;
 640        BlockPoint(output_start + input_overshoot)
 641    }
 642
 643    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 644        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 645        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 646        if let Some(transform) = cursor.item() {
 647            match transform.block.as_ref().map(|b| b.disposition) {
 648                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 649                Some(BlockDisposition::Below) => {
 650                    let wrap_row = cursor.start().1 .0 - 1;
 651                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 652                }
 653                None => {
 654                    let overshoot = block_point.row - cursor.start().0 .0;
 655                    let wrap_row = cursor.start().1 .0 + overshoot;
 656                    WrapPoint::new(wrap_row, block_point.column)
 657                }
 658            }
 659        } else {
 660            self.wrap_snapshot.max_point()
 661        }
 662    }
 663}
 664
 665impl Transform {
 666    fn isomorphic(rows: u32) -> Self {
 667        Self {
 668            summary: TransformSummary {
 669                input_rows: rows,
 670                output_rows: rows,
 671            },
 672            block: None,
 673        }
 674    }
 675
 676    fn block(block: Arc<Block>, column: u32) -> Self {
 677        Self {
 678            summary: TransformSummary {
 679                input_rows: 0,
 680                output_rows: block.height as u32,
 681            },
 682            block: Some(AlignedBlock { block, column }),
 683        }
 684    }
 685
 686    fn is_isomorphic(&self) -> bool {
 687        self.block.is_none()
 688    }
 689}
 690
 691impl<'a> Iterator for BlockChunks<'a> {
 692    type Item = Chunk<'a>;
 693
 694    fn next(&mut self) -> Option<Self::Item> {
 695        if self.output_row >= self.max_output_row {
 696            return None;
 697        }
 698
 699        let transform = self.transforms.item()?;
 700        if transform.block.is_some() {
 701            let block_start = self.transforms.start().0 .0;
 702            let mut block_end = self.transforms.end(&()).0 .0;
 703            self.transforms.next(&());
 704            if self.transforms.item().is_none() {
 705                block_end -= 1;
 706            }
 707
 708            let start_in_block = self.output_row - block_start;
 709            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 710            let line_count = end_in_block - start_in_block;
 711            self.output_row += line_count;
 712
 713            return Some(Chunk {
 714                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 715                highlight_style: None,
 716                diagnostic: None,
 717            });
 718        }
 719
 720        if self.input_chunk.text.is_empty() {
 721            if let Some(input_chunk) = self.input_chunks.next() {
 722                self.input_chunk = input_chunk;
 723            } else {
 724                self.output_row += 1;
 725                if self.output_row < self.max_output_row {
 726                    self.transforms.next(&());
 727                    return Some(Chunk {
 728                        text: "\n",
 729                        ..Default::default()
 730                    });
 731                } else {
 732                    return None;
 733                }
 734            }
 735        }
 736
 737        let transform_end = self.transforms.end(&()).0 .0;
 738        let (prefix_rows, prefix_bytes) =
 739            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 740        self.output_row += prefix_rows;
 741        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 742        self.input_chunk.text = suffix;
 743        if self.output_row == transform_end {
 744            self.transforms.next(&());
 745        }
 746
 747        Some(Chunk {
 748            text: prefix,
 749            ..self.input_chunk
 750        })
 751    }
 752}
 753
 754impl<'a> Iterator for BlockBufferRows<'a> {
 755    type Item = Option<u32>;
 756
 757    fn next(&mut self) -> Option<Self::Item> {
 758        if self.started {
 759            self.output_row += 1;
 760        } else {
 761            self.started = true;
 762        }
 763
 764        if self.output_row >= self.transforms.end(&()).0 .0 {
 765            self.transforms.next(&());
 766        }
 767
 768        let transform = self.transforms.item()?;
 769        if transform.block.is_some() {
 770            Some(None)
 771        } else {
 772            Some(self.input_buffer_rows.next().unwrap())
 773        }
 774    }
 775}
 776
 777impl sum_tree::Item for Transform {
 778    type Summary = TransformSummary;
 779
 780    fn summary(&self) -> Self::Summary {
 781        self.summary.clone()
 782    }
 783}
 784
 785impl sum_tree::Summary for TransformSummary {
 786    type Context = ();
 787
 788    fn add_summary(&mut self, summary: &Self, _: &()) {
 789        self.input_rows += summary.input_rows;
 790        self.output_rows += summary.output_rows;
 791    }
 792}
 793
 794impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 795    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 796        self.0 += summary.input_rows;
 797    }
 798}
 799
 800impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 801    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 802        self.0 += summary.output_rows;
 803    }
 804}
 805
 806impl BlockDisposition {
 807    fn is_below(&self) -> bool {
 808        matches!(self, BlockDisposition::Below)
 809    }
 810}
 811
 812impl AlignedBlock {
 813    pub fn height(&self) -> u32 {
 814        self.height as u32
 815    }
 816
 817    pub fn column(&self) -> u32 {
 818        self.column
 819    }
 820
 821    pub fn render(&self, cx: &BlockContext) -> ElementBox {
 822        self.render.lock()(cx)
 823    }
 824
 825    pub fn position(&self) -> &Anchor {
 826        &self.block.position
 827    }
 828}
 829
 830impl Deref for AlignedBlock {
 831    type Target = Block;
 832
 833    fn deref(&self) -> &Self::Target {
 834        self.block.as_ref()
 835    }
 836}
 837
 838impl<'a> Deref for BlockContext<'a> {
 839    type Target = AppContext;
 840
 841    fn deref(&self) -> &Self::Target {
 842        &self.cx
 843    }
 844}
 845
 846impl Debug for Block {
 847    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 848        f.debug_struct("Block")
 849            .field("id", &self.id)
 850            .field("position", &self.position)
 851            .field("disposition", &self.disposition)
 852            .finish()
 853    }
 854}
 855
 856// Count the number of bytes prior to a target point. If the string doesn't contain the target
 857// point, return its total extent. Otherwise return the target point itself.
 858fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 859    let mut row = 0;
 860    let mut offset = 0;
 861    for (ix, line) in s.split('\n').enumerate() {
 862        if ix > 0 {
 863            row += 1;
 864            offset += 1;
 865        }
 866        if row >= target {
 867            break;
 868        }
 869        offset += line.len() as usize;
 870    }
 871    (row, offset)
 872}
 873
 874#[cfg(test)]
 875mod tests {
 876    use super::*;
 877    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 878    use crate::multi_buffer::MultiBuffer;
 879    use gpui::{elements::Empty, Element};
 880    use rand::prelude::*;
 881    use std::env;
 882    use text::RandomCharIter;
 883
 884    #[gpui::test]
 885    fn test_offset_for_row() {
 886        assert_eq!(offset_for_row("", 0), (0, 0));
 887        assert_eq!(offset_for_row("", 1), (0, 0));
 888        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 889        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 890        assert_eq!(offset_for_row("\n", 0), (0, 0));
 891        assert_eq!(offset_for_row("\n", 1), (1, 1));
 892        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 893        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 894        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 895        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 896    }
 897
 898    #[gpui::test]
 899    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 900        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 901        let font_id = cx
 902            .font_cache()
 903            .select_font(family_id, &Default::default())
 904            .unwrap();
 905
 906        let text = "aaa\nbbb\nccc\nddd";
 907
 908        let buffer = MultiBuffer::build_simple(text, cx);
 909        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
 910        let (fold_map, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot(cx));
 911        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 912        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 913        let mut block_map = BlockMap::new(wraps_snapshot.clone());
 914
 915        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
 916        writer.insert(vec![
 917            BlockProperties {
 918                position: Point::new(1, 0),
 919                height: 1,
 920                disposition: BlockDisposition::Above,
 921                render: Arc::new(|_| Empty::new().named("block 1")),
 922            },
 923            BlockProperties {
 924                position: Point::new(1, 2),
 925                height: 2,
 926                disposition: BlockDisposition::Above,
 927                render: Arc::new(|_| Empty::new().named("block 2")),
 928            },
 929            BlockProperties {
 930                position: Point::new(3, 3),
 931                height: 3,
 932                disposition: BlockDisposition::Below,
 933                render: Arc::new(|_| Empty::new().named("block 3")),
 934            },
 935        ]);
 936
 937        let mut snapshot = block_map.read(wraps_snapshot, vec![]);
 938        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
 939
 940        let blocks = snapshot
 941            .blocks_in_range(0..8)
 942            .map(|(start_row, block)| {
 943                (
 944                    start_row..start_row + block.height(),
 945                    block.column(),
 946                    block
 947                        .render(&BlockContext { cx, anchor_x: 0. })
 948                        .name()
 949                        .unwrap()
 950                        .to_string(),
 951                )
 952            })
 953            .collect::<Vec<_>>();
 954        assert_eq!(
 955            blocks,
 956            &[
 957                (1..2, 0, "block 1".to_string()),
 958                (2..4, 2, "block 2".to_string()),
 959                (7..10, 3, "block 3".to_string()),
 960            ]
 961        );
 962
 963        assert_eq!(
 964            snapshot.to_block_point(WrapPoint::new(0, 3)),
 965            BlockPoint::new(0, 3)
 966        );
 967        assert_eq!(
 968            snapshot.to_block_point(WrapPoint::new(1, 0)),
 969            BlockPoint::new(4, 0)
 970        );
 971        assert_eq!(
 972            snapshot.to_block_point(WrapPoint::new(3, 3)),
 973            BlockPoint::new(6, 3)
 974        );
 975
 976        assert_eq!(
 977            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
 978            WrapPoint::new(0, 3)
 979        );
 980        assert_eq!(
 981            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
 982            WrapPoint::new(1, 0)
 983        );
 984        assert_eq!(
 985            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
 986            WrapPoint::new(1, 0)
 987        );
 988        assert_eq!(
 989            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
 990            WrapPoint::new(3, 3)
 991        );
 992
 993        assert_eq!(
 994            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
 995            BlockPoint::new(0, 3)
 996        );
 997        assert_eq!(
 998            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
 999            BlockPoint::new(4, 0)
1000        );
1001        assert_eq!(
1002            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1003            BlockPoint::new(0, 3)
1004        );
1005        assert_eq!(
1006            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1007            BlockPoint::new(4, 0)
1008        );
1009        assert_eq!(
1010            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1011            BlockPoint::new(4, 0)
1012        );
1013        assert_eq!(
1014            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1015            BlockPoint::new(4, 0)
1016        );
1017        assert_eq!(
1018            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1019            BlockPoint::new(6, 3)
1020        );
1021        assert_eq!(
1022            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1023            BlockPoint::new(6, 3)
1024        );
1025        assert_eq!(
1026            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1027            BlockPoint::new(6, 3)
1028        );
1029        assert_eq!(
1030            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1031            BlockPoint::new(6, 3)
1032        );
1033
1034        assert_eq!(
1035            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1036            &[
1037                Some(0),
1038                None,
1039                None,
1040                None,
1041                Some(1),
1042                Some(2),
1043                Some(3),
1044                None,
1045                None,
1046                None
1047            ]
1048        );
1049
1050        // Insert a line break, separating two block decorations into separate lines.
1051        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1052            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
1053            buffer.snapshot(cx)
1054        });
1055
1056        let (folds_snapshot, fold_edits) =
1057            fold_map.read(buffer_snapshot, subscription.consume().into_inner());
1058        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1059        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1060            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1061        });
1062        let mut snapshot = block_map.read(wraps_snapshot, wrap_edits);
1063        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1064    }
1065
1066    #[gpui::test]
1067    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1068        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1069        let font_id = cx
1070            .font_cache()
1071            .select_font(family_id, &Default::default())
1072            .unwrap();
1073
1074        let text = "one two three\nfour five six\nseven eight";
1075
1076        let buffer = MultiBuffer::build_simple(text, cx);
1077        let (_, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot(cx));
1078        let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
1079        let (_, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, Some(60.), cx);
1080        let mut block_map = BlockMap::new(wraps_snapshot.clone());
1081
1082        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
1083        writer.insert(vec![
1084            BlockProperties {
1085                position: Point::new(1, 12),
1086                disposition: BlockDisposition::Above,
1087                render: Arc::new(|_| Empty::new().named("block 1")),
1088                height: 1,
1089            },
1090            BlockProperties {
1091                position: Point::new(1, 1),
1092                disposition: BlockDisposition::Below,
1093                render: Arc::new(|_| Empty::new().named("block 2")),
1094                height: 1,
1095            },
1096        ]);
1097
1098        // Blocks with an 'above' disposition go above their corresponding buffer line.
1099        // Blocks with a 'below' disposition go below their corresponding buffer line.
1100        let mut snapshot = block_map.read(wraps_snapshot, vec![]);
1101        assert_eq!(
1102            snapshot.text(),
1103            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1104        );
1105    }
1106
1107    #[gpui::test(iterations = 100)]
1108    fn test_random_blocks(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
1109        let operations = env::var("OPERATIONS")
1110            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1111            .unwrap_or(10);
1112
1113        let wrap_width = if rng.gen_bool(0.2) {
1114            None
1115        } else {
1116            Some(rng.gen_range(0.0..=100.0))
1117        };
1118        let tab_size = 1;
1119        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1120        let font_id = cx
1121            .font_cache()
1122            .select_font(family_id, &Default::default())
1123            .unwrap();
1124        let font_size = 14.0;
1125
1126        log::info!("Wrap width: {:?}", wrap_width);
1127
1128        let buffer = if rng.gen() {
1129            let len = rng.gen_range(0..10);
1130            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1131            log::info!("initial buffer text: {:?}", text);
1132            MultiBuffer::build_simple(&text, cx)
1133        } else {
1134            MultiBuffer::build_random(&mut rng, cx)
1135        };
1136
1137        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1138        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1139        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1140        let (wrap_map, wraps_snapshot) =
1141            WrapMap::new(tabs_snapshot, font_id, font_size, wrap_width, cx);
1142        let mut block_map = BlockMap::new(wraps_snapshot);
1143        let mut expected_blocks = Vec::new();
1144
1145        for _ in 0..operations {
1146            let mut buffer_edits = Vec::new();
1147            match rng.gen_range(0..=100) {
1148                0..=19 => {
1149                    let wrap_width = if rng.gen_bool(0.2) {
1150                        None
1151                    } else {
1152                        Some(rng.gen_range(0.0..=100.0))
1153                    };
1154                    log::info!("Setting wrap width to {:?}", wrap_width);
1155                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1156                }
1157                20..=39 => {
1158                    let block_count = rng.gen_range(1..=1);
1159                    let block_properties = (0..block_count)
1160                        .map(|_| {
1161                            let buffer = buffer.read(cx).read(cx);
1162                            let position = buffer.anchor_after(
1163                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1164                            );
1165
1166                            let disposition = if rng.gen() {
1167                                BlockDisposition::Above
1168                            } else {
1169                                BlockDisposition::Below
1170                            };
1171                            let height = rng.gen_range(1..5);
1172                            log::info!(
1173                                "inserting block {:?} {:?} with height {}",
1174                                disposition,
1175                                position.to_point(&buffer),
1176                                height
1177                            );
1178                            BlockProperties {
1179                                position,
1180                                height,
1181                                disposition,
1182                                render: Arc::new(|_| Empty::new().boxed()),
1183                            }
1184                        })
1185                        .collect::<Vec<_>>();
1186
1187                    let (folds_snapshot, fold_edits) =
1188                        fold_map.read(buffer_snapshot.clone(), vec![]);
1189                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1190                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1191                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1192                    });
1193                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1194                    let block_ids = block_map.insert(block_properties.clone());
1195                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1196                        expected_blocks.push((block_id, props));
1197                    }
1198                }
1199                40..=59 if !expected_blocks.is_empty() => {
1200                    let block_count = rng.gen_range(1..=4.min(expected_blocks.len()));
1201                    let block_ids_to_remove = (0..block_count)
1202                        .map(|_| {
1203                            expected_blocks
1204                                .remove(rng.gen_range(0..expected_blocks.len()))
1205                                .0
1206                        })
1207                        .collect();
1208
1209                    let (folds_snapshot, fold_edits) =
1210                        fold_map.read(buffer_snapshot.clone(), vec![]);
1211                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1212                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1213                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1214                    });
1215                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1216                    block_map.remove(block_ids_to_remove);
1217                }
1218                _ => {
1219                    buffer.update(cx, |buffer, cx| {
1220                        let edit_count = rng.gen_range(1..=5);
1221                        let subscription = buffer.subscribe();
1222                        buffer.randomly_edit(&mut rng, edit_count, cx);
1223                        buffer_snapshot = buffer.snapshot(cx);
1224                        buffer_edits.extend(subscription.consume());
1225                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1226                    });
1227                }
1228            }
1229
1230            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1231            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1232            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1233                wrap_map.sync(tabs_snapshot, tab_edits, cx)
1234            });
1235            let mut blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1236            assert_eq!(
1237                blocks_snapshot.transforms.summary().input_rows,
1238                wraps_snapshot.max_point().row() + 1
1239            );
1240            log::info!("blocks text: {:?}", blocks_snapshot.text());
1241
1242            let mut sorted_blocks = expected_blocks
1243                .iter()
1244                .cloned()
1245                .map(|(id, block)| {
1246                    let mut position = block.position.to_point(&buffer_snapshot);
1247                    let column = wraps_snapshot.from_point(position, Bias::Left).column();
1248                    match block.disposition {
1249                        BlockDisposition::Above => {
1250                            position.column = 0;
1251                        }
1252                        BlockDisposition::Below => {
1253                            position.column = buffer_snapshot.line_len(position.row);
1254                        }
1255                    };
1256                    let row = wraps_snapshot.from_point(position, Bias::Left).row();
1257                    (
1258                        id,
1259                        BlockProperties {
1260                            position: BlockPoint::new(row, column),
1261                            height: block.height,
1262                            disposition: block.disposition,
1263                            render: block.render.clone(),
1264                        },
1265                    )
1266                })
1267                .collect::<Vec<_>>();
1268            sorted_blocks
1269                .sort_unstable_by_key(|(id, block)| (block.position.row, block.disposition, *id));
1270            let mut sorted_blocks = sorted_blocks.into_iter().peekable();
1271
1272            let mut expected_buffer_rows = Vec::new();
1273            let mut expected_text = String::new();
1274            let input_text = wraps_snapshot.text();
1275            for (row, input_line) in input_text.split('\n').enumerate() {
1276                let row = row as u32;
1277                if row > 0 {
1278                    expected_text.push('\n');
1279                }
1280
1281                let buffer_row = wraps_snapshot
1282                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1283                    .row;
1284
1285                while let Some((_, block)) = sorted_blocks.peek() {
1286                    if block.position.row == row && block.disposition == BlockDisposition::Above {
1287                        let text = "\n".repeat(block.height as usize);
1288                        expected_text.push_str(&text);
1289                        for _ in 0..block.height {
1290                            expected_buffer_rows.push(None);
1291                        }
1292                        sorted_blocks.next();
1293                    } else {
1294                        break;
1295                    }
1296                }
1297
1298                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1299                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
1300                expected_text.push_str(input_line);
1301
1302                while let Some((_, block)) = sorted_blocks.peek() {
1303                    if block.position.row == row && block.disposition == BlockDisposition::Below {
1304                        let text = "\n".repeat(block.height as usize);
1305                        expected_text.push_str(&text);
1306                        for _ in 0..block.height {
1307                            expected_buffer_rows.push(None);
1308                        }
1309                        sorted_blocks.next();
1310                    } else {
1311                        break;
1312                    }
1313                }
1314            }
1315
1316            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1317            let expected_row_count = expected_lines.len();
1318            for start_row in 0..expected_row_count {
1319                let expected_text = expected_lines[start_row..].join("\n");
1320                let actual_text = blocks_snapshot
1321                    .chunks(start_row as u32..expected_row_count as u32, None)
1322                    .map(|chunk| chunk.text)
1323                    .collect::<String>();
1324                assert_eq!(
1325                    actual_text, expected_text,
1326                    "incorrect text starting from row {}",
1327                    start_row
1328                );
1329                assert_eq!(
1330                    blocks_snapshot
1331                        .buffer_rows(start_row as u32)
1332                        .collect::<Vec<_>>(),
1333                    &expected_buffer_rows[start_row..]
1334                );
1335            }
1336
1337            let mut expected_longest_rows = Vec::new();
1338            let mut longest_line_len = -1_isize;
1339            for (row, line) in expected_lines.iter().enumerate() {
1340                let row = row as u32;
1341
1342                assert_eq!(
1343                    blocks_snapshot.line_len(row),
1344                    line.len() as u32,
1345                    "invalid line len for row {}",
1346                    row
1347                );
1348
1349                let line_char_count = line.chars().count() as isize;
1350                match line_char_count.cmp(&longest_line_len) {
1351                    Ordering::Less => {}
1352                    Ordering::Equal => expected_longest_rows.push(row),
1353                    Ordering::Greater => {
1354                        longest_line_len = line_char_count;
1355                        expected_longest_rows.clear();
1356                        expected_longest_rows.push(row);
1357                    }
1358                }
1359            }
1360
1361            let longest_row = blocks_snapshot.longest_row();
1362            assert!(
1363                expected_longest_rows.contains(&longest_row),
1364                "incorrect longest row {}. expected {:?} with length {}",
1365                longest_row,
1366                expected_longest_rows,
1367                longest_line_len,
1368            );
1369
1370            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1371                let wrap_point = WrapPoint::new(row, 0);
1372                let block_point = blocks_snapshot.to_block_point(wrap_point);
1373                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1374            }
1375
1376            let mut block_point = BlockPoint::new(0, 0);
1377            for c in expected_text.chars() {
1378                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1379                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1380                assert_eq!(
1381                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1382                    left_point
1383                );
1384                assert_eq!(
1385                    left_buffer_point,
1386                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1387                    "{:?} is not valid in buffer coordinates",
1388                    left_point
1389                );
1390
1391                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1392                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1393                assert_eq!(
1394                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1395                    right_point
1396                );
1397                assert_eq!(
1398                    right_buffer_point,
1399                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1400                    "{:?} is not valid in buffer coordinates",
1401                    right_point
1402                );
1403
1404                if c == '\n' {
1405                    block_point.0 += Point::new(1, 0);
1406                } else {
1407                    block_point.column += c.len_utf8() as u32;
1408                }
1409            }
1410        }
1411    }
1412
1413    impl BlockSnapshot {
1414        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1415            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1416        }
1417    }
1418}