block_map.rs

   1use super::wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot};
   2use crate::{Anchor, ToPoint as _};
   3use collections::{Bound, HashMap, HashSet};
   4use gpui::{AppContext, ElementBox};
   5use language::{BufferSnapshot, 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};
  18
  19const NEWLINES: &'static [u8] = &[b'\n'; u8::MAX as usize];
  20
  21pub struct BlockMap {
  22    next_block_id: AtomicUsize,
  23    wrap_snapshot: Mutex<WrapSnapshot>,
  24    blocks: Vec<Arc<Block>>,
  25    transforms: Mutex<SumTree<Transform>>,
  26    excerpt_header_height: u8,
  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 scroll_x: f32,
  73    pub gutter_width: f32,
  74    pub gutter_padding: f32,
  75    pub em_width: f32,
  76    pub line_height: f32,
  77}
  78
  79#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  80pub enum BlockDisposition {
  81    Above,
  82    Below,
  83}
  84
  85#[derive(Clone, Debug)]
  86struct Transform {
  87    summary: TransformSummary,
  88    block: Option<TransformBlock>,
  89}
  90
  91#[derive(Clone)]
  92pub enum TransformBlock {
  93    Custom {
  94        block: Arc<Block>,
  95        column: u32,
  96    },
  97    ExcerptHeader {
  98        buffer: BufferSnapshot,
  99        range: Range<text::Anchor>,
 100        height: u8,
 101    },
 102}
 103
 104impl TransformBlock {
 105    fn disposition(&self) -> BlockDisposition {
 106        match self {
 107            TransformBlock::Custom { block, .. } => block.disposition,
 108            TransformBlock::ExcerptHeader { .. } => BlockDisposition::Above,
 109        }
 110    }
 111
 112    fn height(&self) -> u8 {
 113        match self {
 114            TransformBlock::Custom { block, .. } => block.height,
 115            TransformBlock::ExcerptHeader { height, .. } => *height,
 116        }
 117    }
 118}
 119
 120impl Debug for TransformBlock {
 121    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 122        match self {
 123            Self::Custom { block, column } => f
 124                .debug_struct("Custom")
 125                .field("block", block)
 126                .field("column", column)
 127                .finish(),
 128            Self::ExcerptHeader { buffer, .. } => f
 129                .debug_struct("ExcerptHeader")
 130                .field("path", &buffer.path())
 131                .finish(),
 132        }
 133    }
 134}
 135
 136#[derive(Clone, Debug, Default)]
 137struct TransformSummary {
 138    input_rows: u32,
 139    output_rows: u32,
 140}
 141
 142pub struct BlockChunks<'a> {
 143    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 144    input_chunks: wrap_map::WrapChunks<'a>,
 145    input_chunk: Chunk<'a>,
 146    output_row: u32,
 147    max_output_row: u32,
 148}
 149
 150pub struct BlockBufferRows<'a> {
 151    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 152    input_buffer_rows: wrap_map::WrapBufferRows<'a>,
 153    output_row: u32,
 154    started: bool,
 155}
 156
 157impl BlockMap {
 158    pub fn new(wrap_snapshot: WrapSnapshot, excerpt_header_height: u8) -> Self {
 159        let row_count = wrap_snapshot.max_point().row() + 1;
 160        let map = Self {
 161            next_block_id: AtomicUsize::new(0),
 162            blocks: Vec::new(),
 163            transforms: Mutex::new(SumTree::from_item(Transform::isomorphic(row_count), &())),
 164            wrap_snapshot: Mutex::new(wrap_snapshot.clone()),
 165            excerpt_header_height,
 166        };
 167        map.sync(
 168            &wrap_snapshot,
 169            vec![Edit {
 170                old: 0..row_count,
 171                new: 0..row_count,
 172            }],
 173        );
 174        map
 175    }
 176
 177    pub fn read(&self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockSnapshot {
 178        self.sync(&wrap_snapshot, edits);
 179        *self.wrap_snapshot.lock() = wrap_snapshot.clone();
 180        BlockSnapshot {
 181            wrap_snapshot,
 182            transforms: self.transforms.lock().clone(),
 183        }
 184    }
 185
 186    pub fn write(&mut self, wrap_snapshot: WrapSnapshot, edits: Vec<WrapEdit>) -> BlockMapWriter {
 187        self.sync(&wrap_snapshot, edits);
 188        *self.wrap_snapshot.lock() = wrap_snapshot;
 189        BlockMapWriter(self)
 190    }
 191
 192    fn sync(&self, wrap_snapshot: &WrapSnapshot, edits: Vec<WrapEdit>) {
 193        if edits.is_empty() {
 194            return;
 195        }
 196
 197        let buffer = wrap_snapshot.buffer_snapshot();
 198        let mut transforms = self.transforms.lock();
 199        let mut new_transforms = SumTree::new();
 200        let old_row_count = transforms.summary().input_rows;
 201        let new_row_count = wrap_snapshot.max_point().row() + 1;
 202        let mut cursor = transforms.cursor::<WrapRow>();
 203        let mut last_block_ix = 0;
 204        let mut blocks_in_edit = Vec::new();
 205        let mut edits = edits.into_iter().peekable();
 206
 207        while let Some(edit) = edits.next() {
 208            // Preserve any old transforms that precede this edit.
 209            let old_start = WrapRow(edit.old.start);
 210            let new_start = WrapRow(edit.new.start);
 211            new_transforms.push_tree(cursor.slice(&old_start, Bias::Left, &()), &());
 212            if let Some(transform) = cursor.item() {
 213                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 214                    new_transforms.push(transform.clone(), &());
 215                    cursor.next(&());
 216                    while let Some(transform) = cursor.item() {
 217                        if transform
 218                            .block
 219                            .as_ref()
 220                            .map_or(false, |b| b.disposition().is_below())
 221                        {
 222                            new_transforms.push(transform.clone(), &());
 223                            cursor.next(&());
 224                        } else {
 225                            break;
 226                        }
 227                    }
 228                }
 229            }
 230
 231            // Preserve any portion of an old transform that precedes this edit.
 232            let extent_before_edit = old_start.0 - cursor.start().0;
 233            push_isomorphic(&mut new_transforms, extent_before_edit);
 234
 235            // Skip over any old transforms that intersect this edit.
 236            let mut old_end = WrapRow(edit.old.end);
 237            let mut new_end = WrapRow(edit.new.end);
 238            cursor.seek(&old_end, Bias::Left, &());
 239            cursor.next(&());
 240            if old_end == *cursor.start() {
 241                while let Some(transform) = cursor.item() {
 242                    if transform
 243                        .block
 244                        .as_ref()
 245                        .map_or(false, |b| b.disposition().is_below())
 246                    {
 247                        cursor.next(&());
 248                    } else {
 249                        break;
 250                    }
 251                }
 252            }
 253
 254            // Combine this edit with any subsequent edits that intersect the same transform.
 255            while let Some(next_edit) = edits.peek() {
 256                if next_edit.old.start <= cursor.start().0 {
 257                    old_end = WrapRow(next_edit.old.end);
 258                    new_end = WrapRow(next_edit.new.end);
 259                    cursor.seek(&old_end, Bias::Left, &());
 260                    cursor.next(&());
 261                    if old_end == *cursor.start() {
 262                        while let Some(transform) = cursor.item() {
 263                            if transform
 264                                .block
 265                                .as_ref()
 266                                .map_or(false, |b| b.disposition().is_below())
 267                            {
 268                                cursor.next(&());
 269                            } else {
 270                                break;
 271                            }
 272                        }
 273                    }
 274                    edits.next();
 275                } else {
 276                    break;
 277                }
 278            }
 279
 280            // Find the blocks within this edited region.
 281            let new_buffer_start =
 282                wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 283            let start_anchor = buffer.anchor_before(new_buffer_start);
 284            let start_bound = Bound::Included(start_anchor.clone());
 285            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 286                probe
 287                    .position
 288                    .cmp(&start_anchor, &buffer)
 289                    .unwrap()
 290                    .then(Ordering::Greater)
 291            }) {
 292                Ok(ix) | Err(ix) => last_block_ix + ix,
 293            };
 294
 295            let end_bound;
 296            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 297                end_bound = Bound::Unbounded;
 298                self.blocks.len()
 299            } else {
 300                let new_buffer_end =
 301                    wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 302                let end_anchor = buffer.anchor_before(new_buffer_end);
 303                end_bound = Bound::Excluded(end_anchor.clone());
 304                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 305                    probe
 306                        .position
 307                        .cmp(&end_anchor, &buffer)
 308                        .unwrap()
 309                        .then(Ordering::Greater)
 310                }) {
 311                    Ok(ix) | Err(ix) => start_block_ix + ix,
 312                }
 313            };
 314            last_block_ix = end_block_ix;
 315
 316            debug_assert!(blocks_in_edit.is_empty());
 317            blocks_in_edit.extend(
 318                self.blocks[start_block_ix..end_block_ix]
 319                    .iter()
 320                    .map(|block| {
 321                        let mut position = block.position.to_point(&buffer);
 322                        let column = wrap_snapshot.from_point(position, Bias::Left).column();
 323                        match block.disposition {
 324                            BlockDisposition::Above => position.column = 0,
 325                            BlockDisposition::Below => {
 326                                position.column = buffer.line_len(position.row)
 327                            }
 328                        }
 329                        let position = wrap_snapshot.from_point(position, Bias::Left);
 330                        (
 331                            position.row(),
 332                            TransformBlock::Custom {
 333                                block: block.clone(),
 334                                column,
 335                            },
 336                        )
 337                    }),
 338            );
 339            blocks_in_edit.extend(
 340                buffer
 341                    .excerpt_boundaries_in_range((start_bound, end_bound))
 342                    .map(|excerpt_boundary| {
 343                        (
 344                            wrap_snapshot
 345                                .from_point(Point::new(excerpt_boundary.row, 0), Bias::Left)
 346                                .row(),
 347                            TransformBlock::ExcerptHeader {
 348                                buffer: excerpt_boundary.buffer,
 349                                range: excerpt_boundary.range,
 350                                height: self.excerpt_header_height,
 351                            },
 352                        )
 353                    }),
 354            );
 355
 356            // Place excerpt headers above custom blocks on the same row.
 357            blocks_in_edit.sort_unstable_by(|(row_a, block_a), (row_b, block_b)| {
 358                row_a.cmp(&row_b).then_with(|| match (block_a, block_b) {
 359                    (
 360                        TransformBlock::ExcerptHeader { .. },
 361                        TransformBlock::ExcerptHeader { .. },
 362                    ) => Ordering::Equal,
 363                    (TransformBlock::ExcerptHeader { .. }, _) => Ordering::Less,
 364                    (_, TransformBlock::ExcerptHeader { .. }) => Ordering::Greater,
 365                    (
 366                        TransformBlock::Custom { block: block_a, .. },
 367                        TransformBlock::Custom { block: block_b, .. },
 368                    ) => block_a
 369                        .disposition
 370                        .cmp(&block_b.disposition)
 371                        .then_with(|| block_a.id.cmp(&block_b.id)),
 372                })
 373            });
 374
 375            // For each of these blocks, insert a new isomorphic transform preceding the block,
 376            // and then insert the block itself.
 377            for (block_row, block) in blocks_in_edit.drain(..) {
 378                let insertion_row = match block.disposition() {
 379                    BlockDisposition::Above => block_row,
 380                    BlockDisposition::Below => block_row + 1,
 381                };
 382                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 383                push_isomorphic(&mut new_transforms, extent_before_block);
 384                new_transforms.push(Transform::block(block), &());
 385            }
 386
 387            old_end = WrapRow(old_end.0.min(old_row_count));
 388            new_end = WrapRow(new_end.0.min(new_row_count));
 389
 390            // Insert an isomorphic transform after the final block.
 391            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 392            push_isomorphic(&mut new_transforms, extent_after_last_block);
 393
 394            // Preserve any portion of the old transform after this edit.
 395            let extent_after_edit = cursor.start().0 - old_end.0;
 396            push_isomorphic(&mut new_transforms, extent_after_edit);
 397        }
 398
 399        new_transforms.push_tree(cursor.suffix(&()), &());
 400        debug_assert_eq!(
 401            new_transforms.summary().input_rows,
 402            wrap_snapshot.max_point().row() + 1
 403        );
 404
 405        drop(cursor);
 406        *transforms = new_transforms;
 407    }
 408
 409    pub fn replace(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 410        for block in &self.blocks {
 411            if let Some(render) = renderers.remove(&block.id) {
 412                *block.render.lock() = render;
 413            }
 414        }
 415    }
 416}
 417
 418fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 419    if rows == 0 {
 420        return;
 421    }
 422
 423    let mut extent = Some(rows);
 424    tree.update_last(
 425        |last_transform| {
 426            if last_transform.is_isomorphic() {
 427                let extent = extent.take().unwrap();
 428                last_transform.summary.input_rows += extent;
 429                last_transform.summary.output_rows += extent;
 430            }
 431        },
 432        &(),
 433    );
 434    if let Some(extent) = extent {
 435        tree.push(Transform::isomorphic(extent), &());
 436    }
 437}
 438
 439impl BlockPoint {
 440    pub fn new(row: u32, column: u32) -> Self {
 441        Self(Point::new(row, column))
 442    }
 443}
 444
 445impl Deref for BlockPoint {
 446    type Target = Point;
 447
 448    fn deref(&self) -> &Self::Target {
 449        &self.0
 450    }
 451}
 452
 453impl std::ops::DerefMut for BlockPoint {
 454    fn deref_mut(&mut self) -> &mut Self::Target {
 455        &mut self.0
 456    }
 457}
 458
 459impl<'a> BlockMapWriter<'a> {
 460    pub fn insert(
 461        &mut self,
 462        blocks: impl IntoIterator<Item = BlockProperties<Anchor>>,
 463    ) -> Vec<BlockId> {
 464        let mut ids = Vec::new();
 465        let mut edits = Vec::<Edit<u32>>::new();
 466        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 467        let buffer = wrap_snapshot.buffer_snapshot();
 468
 469        for block in blocks {
 470            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 471            ids.push(id);
 472
 473            let position = block.position;
 474            let point = position.to_point(&buffer);
 475            let wrap_row = wrap_snapshot
 476                .from_point(Point::new(point.row, 0), Bias::Left)
 477                .row();
 478            let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 479            let end_row = wrap_snapshot
 480                .next_row_boundary(WrapPoint::new(wrap_row, 0))
 481                .unwrap_or(wrap_snapshot.max_point().row() + 1);
 482
 483            let block_ix = match self
 484                .0
 485                .blocks
 486                .binary_search_by(|probe| probe.position.cmp(&position, &buffer).unwrap())
 487            {
 488                Ok(ix) | Err(ix) => ix,
 489            };
 490            self.0.blocks.insert(
 491                block_ix,
 492                Arc::new(Block {
 493                    id,
 494                    position,
 495                    height: block.height,
 496                    render: Mutex::new(block.render),
 497                    disposition: block.disposition,
 498                }),
 499            );
 500
 501            if let Err(edit_ix) = edits.binary_search_by_key(&start_row, |edit| edit.old.start) {
 502                edits.insert(
 503                    edit_ix,
 504                    Edit {
 505                        old: start_row..end_row,
 506                        new: start_row..end_row,
 507                    },
 508                );
 509            }
 510        }
 511
 512        self.0.sync(wrap_snapshot, edits);
 513        ids
 514    }
 515
 516    pub fn remove(&mut self, block_ids: HashSet<BlockId>) {
 517        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 518        let buffer = wrap_snapshot.buffer_snapshot();
 519        let mut edits = Vec::new();
 520        let mut last_block_buffer_row = None;
 521        self.0.blocks.retain(|block| {
 522            if block_ids.contains(&block.id) {
 523                let buffer_row = block.position.to_point(&buffer).row;
 524                if last_block_buffer_row != Some(buffer_row) {
 525                    last_block_buffer_row = Some(buffer_row);
 526                    let wrap_row = wrap_snapshot
 527                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 528                        .row();
 529                    let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 530                    let end_row = wrap_snapshot
 531                        .next_row_boundary(WrapPoint::new(wrap_row, 0))
 532                        .unwrap_or(wrap_snapshot.max_point().row() + 1);
 533                    edits.push(Edit {
 534                        old: start_row..end_row,
 535                        new: start_row..end_row,
 536                    })
 537                }
 538                false
 539            } else {
 540                true
 541            }
 542        });
 543        self.0.sync(wrap_snapshot, edits);
 544    }
 545}
 546
 547impl BlockSnapshot {
 548    #[cfg(test)]
 549    pub fn text(&self) -> String {
 550        self.chunks(0..self.transforms.summary().output_rows, false)
 551            .map(|chunk| chunk.text)
 552            .collect()
 553    }
 554
 555    pub fn chunks<'a>(&'a self, rows: Range<u32>, language_aware: bool) -> BlockChunks<'a> {
 556        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 557        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 558        let input_end = {
 559            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 560            let overshoot = if cursor
 561                .item()
 562                .map_or(false, |transform| transform.is_isomorphic())
 563            {
 564                rows.end - cursor.start().0 .0
 565            } else {
 566                0
 567            };
 568            cursor.start().1 .0 + overshoot
 569        };
 570        let input_start = {
 571            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 572            let overshoot = if cursor
 573                .item()
 574                .map_or(false, |transform| transform.is_isomorphic())
 575            {
 576                rows.start - cursor.start().0 .0
 577            } else {
 578                0
 579            };
 580            cursor.start().1 .0 + overshoot
 581        };
 582        BlockChunks {
 583            input_chunks: self
 584                .wrap_snapshot
 585                .chunks(input_start..input_end, language_aware),
 586            input_chunk: Default::default(),
 587            transforms: cursor,
 588            output_row: rows.start,
 589            max_output_row,
 590        }
 591    }
 592
 593    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> BlockBufferRows<'a> {
 594        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 595        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 596        let (output_start, input_start) = cursor.start();
 597        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 598            start_row - output_start.0
 599        } else {
 600            0
 601        };
 602        let input_start_row = input_start.0 + overshoot;
 603        BlockBufferRows {
 604            transforms: cursor,
 605            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 606            output_row: start_row,
 607            started: false,
 608        }
 609    }
 610
 611    pub fn blocks_in_range<'a>(
 612        &'a self,
 613        rows: Range<u32>,
 614    ) -> impl Iterator<Item = (u32, &'a TransformBlock)> {
 615        let mut cursor = self.transforms.cursor::<BlockRow>();
 616        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 617        std::iter::from_fn(move || {
 618            while let Some(transform) = cursor.item() {
 619                let start_row = cursor.start().0;
 620                if start_row >= rows.end {
 621                    break;
 622                }
 623                if let Some(block) = &transform.block {
 624                    cursor.next(&());
 625                    return Some((start_row, block));
 626                } else {
 627                    cursor.next(&());
 628                }
 629            }
 630            None
 631        })
 632    }
 633
 634    pub fn max_point(&self) -> BlockPoint {
 635        let row = self.transforms.summary().output_rows - 1;
 636        BlockPoint::new(row, self.line_len(row))
 637    }
 638
 639    pub fn longest_row(&self) -> u32 {
 640        let input_row = self.wrap_snapshot.longest_row();
 641        self.to_block_point(WrapPoint::new(input_row, 0)).row
 642    }
 643
 644    pub fn line_len(&self, row: u32) -> u32 {
 645        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 646        cursor.seek(&BlockRow(row), Bias::Right, &());
 647        if let Some(transform) = cursor.item() {
 648            let (output_start, input_start) = cursor.start();
 649            let overshoot = row - output_start.0;
 650            if transform.block.is_some() {
 651                0
 652            } else {
 653                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 654            }
 655        } else {
 656            panic!("row out of range");
 657        }
 658    }
 659
 660    pub fn is_block_line(&self, row: u32) -> bool {
 661        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 662        cursor.seek(&BlockRow(row), Bias::Right, &());
 663        cursor.item().map_or(false, |t| t.block.is_some())
 664    }
 665
 666    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 667        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 668        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 669
 670        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 671        let mut search_left =
 672            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 673        let mut reversed = false;
 674
 675        loop {
 676            if let Some(transform) = cursor.item() {
 677                if transform.is_isomorphic() {
 678                    let (output_start_row, input_start_row) = cursor.start();
 679                    let (output_end_row, input_end_row) = cursor.end(&());
 680                    let output_start = Point::new(output_start_row.0, 0);
 681                    let input_start = Point::new(input_start_row.0, 0);
 682                    let input_end = Point::new(input_end_row.0, 0);
 683                    let input_point = if point.row >= output_end_row.0 {
 684                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 685                        self.wrap_snapshot
 686                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 687                    } else {
 688                        let output_overshoot = point.0.saturating_sub(output_start);
 689                        self.wrap_snapshot
 690                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 691                    };
 692
 693                    if (input_start..input_end).contains(&input_point.0) {
 694                        let input_overshoot = input_point.0.saturating_sub(input_start);
 695                        return BlockPoint(output_start + input_overshoot);
 696                    }
 697                }
 698
 699                if search_left {
 700                    cursor.prev(&());
 701                } else {
 702                    cursor.next(&());
 703                }
 704            } else if reversed {
 705                return self.max_point();
 706            } else {
 707                reversed = true;
 708                search_left = !search_left;
 709                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 710            }
 711        }
 712    }
 713
 714    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 715        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 716        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 717        if let Some(transform) = cursor.item() {
 718            debug_assert!(transform.is_isomorphic());
 719        } else {
 720            return self.max_point();
 721        }
 722
 723        let (input_start_row, output_start_row) = cursor.start();
 724        let input_start = Point::new(input_start_row.0, 0);
 725        let output_start = Point::new(output_start_row.0, 0);
 726        let input_overshoot = wrap_point.0 - input_start;
 727        BlockPoint(output_start + input_overshoot)
 728    }
 729
 730    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 731        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 732        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 733        if let Some(transform) = cursor.item() {
 734            match transform.block.as_ref().map(|b| b.disposition()) {
 735                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 736                Some(BlockDisposition::Below) => {
 737                    let wrap_row = cursor.start().1 .0 - 1;
 738                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 739                }
 740                None => {
 741                    let overshoot = block_point.row - cursor.start().0 .0;
 742                    let wrap_row = cursor.start().1 .0 + overshoot;
 743                    WrapPoint::new(wrap_row, block_point.column)
 744                }
 745            }
 746        } else {
 747            self.wrap_snapshot.max_point()
 748        }
 749    }
 750}
 751
 752impl Transform {
 753    fn isomorphic(rows: u32) -> Self {
 754        Self {
 755            summary: TransformSummary {
 756                input_rows: rows,
 757                output_rows: rows,
 758            },
 759            block: None,
 760        }
 761    }
 762
 763    fn block(block: TransformBlock) -> Self {
 764        Self {
 765            summary: TransformSummary {
 766                input_rows: 0,
 767                output_rows: block.height() as u32,
 768            },
 769            block: Some(block),
 770        }
 771    }
 772
 773    fn is_isomorphic(&self) -> bool {
 774        self.block.is_none()
 775    }
 776}
 777
 778impl<'a> Iterator for BlockChunks<'a> {
 779    type Item = Chunk<'a>;
 780
 781    fn next(&mut self) -> Option<Self::Item> {
 782        if self.output_row >= self.max_output_row {
 783            return None;
 784        }
 785
 786        let transform = self.transforms.item()?;
 787        if transform.block.is_some() {
 788            let block_start = self.transforms.start().0 .0;
 789            let mut block_end = self.transforms.end(&()).0 .0;
 790            self.transforms.next(&());
 791            if self.transforms.item().is_none() {
 792                block_end -= 1;
 793            }
 794
 795            let start_in_block = self.output_row - block_start;
 796            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 797            let line_count = end_in_block - start_in_block;
 798            self.output_row += line_count;
 799
 800            return Some(Chunk {
 801                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 802                highlight_id: None,
 803                diagnostic: None,
 804            });
 805        }
 806
 807        if self.input_chunk.text.is_empty() {
 808            if let Some(input_chunk) = self.input_chunks.next() {
 809                self.input_chunk = input_chunk;
 810            } else {
 811                self.output_row += 1;
 812                if self.output_row < self.max_output_row {
 813                    self.transforms.next(&());
 814                    return Some(Chunk {
 815                        text: "\n",
 816                        ..Default::default()
 817                    });
 818                } else {
 819                    return None;
 820                }
 821            }
 822        }
 823
 824        let transform_end = self.transforms.end(&()).0 .0;
 825        let (prefix_rows, prefix_bytes) =
 826            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 827        self.output_row += prefix_rows;
 828        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 829        self.input_chunk.text = suffix;
 830        if self.output_row == transform_end {
 831            self.transforms.next(&());
 832        }
 833
 834        Some(Chunk {
 835            text: prefix,
 836            ..self.input_chunk
 837        })
 838    }
 839}
 840
 841impl<'a> Iterator for BlockBufferRows<'a> {
 842    type Item = Option<u32>;
 843
 844    fn next(&mut self) -> Option<Self::Item> {
 845        if self.started {
 846            self.output_row += 1;
 847        } else {
 848            self.started = true;
 849        }
 850
 851        if self.output_row >= self.transforms.end(&()).0 .0 {
 852            self.transforms.next(&());
 853        }
 854
 855        let transform = self.transforms.item()?;
 856        if transform.block.is_some() {
 857            Some(None)
 858        } else {
 859            Some(self.input_buffer_rows.next().unwrap())
 860        }
 861    }
 862}
 863
 864impl sum_tree::Item for Transform {
 865    type Summary = TransformSummary;
 866
 867    fn summary(&self) -> Self::Summary {
 868        self.summary.clone()
 869    }
 870}
 871
 872impl sum_tree::Summary for TransformSummary {
 873    type Context = ();
 874
 875    fn add_summary(&mut self, summary: &Self, _: &()) {
 876        self.input_rows += summary.input_rows;
 877        self.output_rows += summary.output_rows;
 878    }
 879}
 880
 881impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 882    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 883        self.0 += summary.input_rows;
 884    }
 885}
 886
 887impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 888    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 889        self.0 += summary.output_rows;
 890    }
 891}
 892
 893impl BlockDisposition {
 894    fn is_below(&self) -> bool {
 895        matches!(self, BlockDisposition::Below)
 896    }
 897}
 898
 899impl<'a> Deref for BlockContext<'a> {
 900    type Target = AppContext;
 901
 902    fn deref(&self) -> &Self::Target {
 903        &self.cx
 904    }
 905}
 906
 907impl Block {
 908    pub fn render(&self, cx: &BlockContext) -> ElementBox {
 909        self.render.lock()(cx)
 910    }
 911}
 912
 913impl Debug for Block {
 914    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 915        f.debug_struct("Block")
 916            .field("id", &self.id)
 917            .field("position", &self.position)
 918            .field("disposition", &self.disposition)
 919            .finish()
 920    }
 921}
 922
 923// Count the number of bytes prior to a target point. If the string doesn't contain the target
 924// point, return its total extent. Otherwise return the target point itself.
 925fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 926    let mut row = 0;
 927    let mut offset = 0;
 928    for (ix, line) in s.split('\n').enumerate() {
 929        if ix > 0 {
 930            row += 1;
 931            offset += 1;
 932        }
 933        if row >= target {
 934            break;
 935        }
 936        offset += line.len() as usize;
 937    }
 938    (row, offset)
 939}
 940
 941#[cfg(test)]
 942mod tests {
 943    use super::*;
 944    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 945    use crate::multi_buffer::MultiBuffer;
 946    use gpui::{elements::Empty, Element};
 947    use rand::prelude::*;
 948    use std::env;
 949    use text::RandomCharIter;
 950
 951    #[gpui::test]
 952    fn test_offset_for_row() {
 953        assert_eq!(offset_for_row("", 0), (0, 0));
 954        assert_eq!(offset_for_row("", 1), (0, 0));
 955        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 956        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 957        assert_eq!(offset_for_row("\n", 0), (0, 0));
 958        assert_eq!(offset_for_row("\n", 1), (1, 1));
 959        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 960        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 961        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 962        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 963    }
 964
 965    #[gpui::test]
 966    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 967        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 968        let font_id = cx
 969            .font_cache()
 970            .select_font(family_id, &Default::default())
 971            .unwrap();
 972
 973        let text = "aaa\nbbb\nccc\nddd";
 974
 975        let buffer = MultiBuffer::build_simple(text, cx);
 976        let buffer_snapshot = buffer.read(cx).snapshot(cx);
 977        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
 978        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
 979        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 980        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 981        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1);
 982
 983        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
 984        writer.insert(vec![
 985            BlockProperties {
 986                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
 987                height: 1,
 988                disposition: BlockDisposition::Above,
 989                render: Arc::new(|_| Empty::new().named("block 1")),
 990            },
 991            BlockProperties {
 992                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
 993                height: 2,
 994                disposition: BlockDisposition::Above,
 995                render: Arc::new(|_| Empty::new().named("block 2")),
 996            },
 997            BlockProperties {
 998                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
 999                height: 3,
1000                disposition: BlockDisposition::Below,
1001                render: Arc::new(|_| Empty::new().named("block 3")),
1002            },
1003        ]);
1004
1005        let snapshot = block_map.read(wraps_snapshot, vec![]);
1006        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1007
1008        let blocks = snapshot
1009            .blocks_in_range(0..8)
1010            .map(|(start_row, block)| {
1011                let (block, column) = block.as_custom().unwrap();
1012                (
1013                    start_row..start_row + block.height as u32,
1014                    column,
1015                    block
1016                        .render(&BlockContext {
1017                            cx,
1018                            anchor_x: 0.,
1019                            gutter_padding: 0.,
1020                            scroll_x: 0.,
1021                            gutter_width: 0.,
1022                            line_height: 0.,
1023                            em_width: 0.,
1024                        })
1025                        .name()
1026                        .unwrap()
1027                        .to_string(),
1028                )
1029            })
1030            .collect::<Vec<_>>();
1031
1032        // When multiple blocks are on the same line, the newer blocks appear first.
1033        assert_eq!(
1034            blocks,
1035            &[
1036                (1..3, 2, "block 2".to_string()),
1037                (3..4, 0, "block 1".to_string()),
1038                (7..10, 3, "block 3".to_string()),
1039            ]
1040        );
1041
1042        assert_eq!(
1043            snapshot.to_block_point(WrapPoint::new(0, 3)),
1044            BlockPoint::new(0, 3)
1045        );
1046        assert_eq!(
1047            snapshot.to_block_point(WrapPoint::new(1, 0)),
1048            BlockPoint::new(4, 0)
1049        );
1050        assert_eq!(
1051            snapshot.to_block_point(WrapPoint::new(3, 3)),
1052            BlockPoint::new(6, 3)
1053        );
1054
1055        assert_eq!(
1056            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
1057            WrapPoint::new(0, 3)
1058        );
1059        assert_eq!(
1060            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
1061            WrapPoint::new(1, 0)
1062        );
1063        assert_eq!(
1064            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
1065            WrapPoint::new(1, 0)
1066        );
1067        assert_eq!(
1068            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
1069            WrapPoint::new(3, 3)
1070        );
1071
1072        assert_eq!(
1073            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
1074            BlockPoint::new(0, 3)
1075        );
1076        assert_eq!(
1077            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1078            BlockPoint::new(4, 0)
1079        );
1080        assert_eq!(
1081            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1082            BlockPoint::new(0, 3)
1083        );
1084        assert_eq!(
1085            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1086            BlockPoint::new(4, 0)
1087        );
1088        assert_eq!(
1089            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1090            BlockPoint::new(4, 0)
1091        );
1092        assert_eq!(
1093            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1094            BlockPoint::new(4, 0)
1095        );
1096        assert_eq!(
1097            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1098            BlockPoint::new(6, 3)
1099        );
1100        assert_eq!(
1101            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1102            BlockPoint::new(6, 3)
1103        );
1104        assert_eq!(
1105            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1106            BlockPoint::new(6, 3)
1107        );
1108        assert_eq!(
1109            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1110            BlockPoint::new(6, 3)
1111        );
1112
1113        assert_eq!(
1114            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1115            &[
1116                Some(0),
1117                None,
1118                None,
1119                None,
1120                Some(1),
1121                Some(2),
1122                Some(3),
1123                None,
1124                None,
1125                None
1126            ]
1127        );
1128
1129        // Insert a line break, separating two block decorations into separate lines.
1130        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1131            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
1132            buffer.snapshot(cx)
1133        });
1134
1135        let (folds_snapshot, fold_edits) =
1136            fold_map.read(buffer_snapshot, subscription.consume().into_inner());
1137        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1138        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1139            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1140        });
1141        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1142        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1143    }
1144
1145    #[gpui::test]
1146    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1147        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1148        let font_id = cx
1149            .font_cache()
1150            .select_font(family_id, &Default::default())
1151            .unwrap();
1152
1153        let text = "one two three\nfour five six\nseven eight";
1154
1155        let buffer = MultiBuffer::build_simple(text, cx);
1156        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1157        let (_, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1158        let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
1159        let (_, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, Some(60.), cx);
1160        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1);
1161
1162        let mut writer = block_map.write(wraps_snapshot.clone(), vec![]);
1163        writer.insert(vec![
1164            BlockProperties {
1165                position: buffer_snapshot.anchor_after(Point::new(1, 12)),
1166                disposition: BlockDisposition::Above,
1167                render: Arc::new(|_| Empty::new().named("block 1")),
1168                height: 1,
1169            },
1170            BlockProperties {
1171                position: buffer_snapshot.anchor_after(Point::new(1, 1)),
1172                disposition: BlockDisposition::Below,
1173                render: Arc::new(|_| Empty::new().named("block 2")),
1174                height: 1,
1175            },
1176        ]);
1177
1178        // Blocks with an 'above' disposition go above their corresponding buffer line.
1179        // Blocks with a 'below' disposition go below their corresponding buffer line.
1180        let snapshot = block_map.read(wraps_snapshot, vec![]);
1181        assert_eq!(
1182            snapshot.text(),
1183            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1184        );
1185    }
1186
1187    #[gpui::test(iterations = 100)]
1188    fn test_random_blocks(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
1189        let operations = env::var("OPERATIONS")
1190            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1191            .unwrap_or(10);
1192
1193        let wrap_width = if rng.gen_bool(0.2) {
1194            None
1195        } else {
1196            Some(rng.gen_range(0.0..=100.0))
1197        };
1198        let tab_size = 1;
1199        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1200        let font_id = cx
1201            .font_cache()
1202            .select_font(family_id, &Default::default())
1203            .unwrap();
1204        let font_size = 14.0;
1205        let excerpt_header_height = rng.gen_range(1..=5);
1206
1207        log::info!("Wrap width: {:?}", wrap_width);
1208        log::info!("Excerpt Header Height: {:?}", excerpt_header_height);
1209
1210        let buffer = if rng.gen() {
1211            let len = rng.gen_range(0..10);
1212            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1213            log::info!("initial buffer text: {:?}", text);
1214            MultiBuffer::build_simple(&text, cx)
1215        } else {
1216            MultiBuffer::build_random(&mut rng, cx)
1217        };
1218
1219        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1220        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1221        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1222        let (wrap_map, wraps_snapshot) =
1223            WrapMap::new(tabs_snapshot, font_id, font_size, wrap_width, cx);
1224        let mut block_map = BlockMap::new(wraps_snapshot.clone(), excerpt_header_height);
1225        let mut custom_blocks = Vec::new();
1226
1227        for _ in 0..operations {
1228            let mut buffer_edits = Vec::new();
1229            match rng.gen_range(0..=100) {
1230                0..=19 => {
1231                    let wrap_width = if rng.gen_bool(0.2) {
1232                        None
1233                    } else {
1234                        Some(rng.gen_range(0.0..=100.0))
1235                    };
1236                    log::info!("Setting wrap width to {:?}", wrap_width);
1237                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1238                }
1239                20..=39 => {
1240                    let block_count = rng.gen_range(1..=5);
1241                    let block_properties = (0..block_count)
1242                        .map(|_| {
1243                            let buffer = buffer.read(cx).read(cx);
1244                            let position = buffer.anchor_after(
1245                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1246                            );
1247
1248                            let disposition = if rng.gen() {
1249                                BlockDisposition::Above
1250                            } else {
1251                                BlockDisposition::Below
1252                            };
1253                            let height = rng.gen_range(1..5);
1254                            log::info!(
1255                                "inserting block {:?} {:?} with height {}",
1256                                disposition,
1257                                position.to_point(&buffer),
1258                                height
1259                            );
1260                            BlockProperties {
1261                                position,
1262                                height,
1263                                disposition,
1264                                render: Arc::new(|_| Empty::new().boxed()),
1265                            }
1266                        })
1267                        .collect::<Vec<_>>();
1268
1269                    let (folds_snapshot, fold_edits) =
1270                        fold_map.read(buffer_snapshot.clone(), vec![]);
1271                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1272                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1273                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1274                    });
1275                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1276                    let block_ids = block_map.insert(block_properties.clone());
1277                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1278                        custom_blocks.push((block_id, props));
1279                    }
1280                }
1281                40..=59 if !custom_blocks.is_empty() => {
1282                    let block_count = rng.gen_range(1..=4.min(custom_blocks.len()));
1283                    let block_ids_to_remove = (0..block_count)
1284                        .map(|_| {
1285                            custom_blocks
1286                                .remove(rng.gen_range(0..custom_blocks.len()))
1287                                .0
1288                        })
1289                        .collect();
1290
1291                    let (folds_snapshot, fold_edits) =
1292                        fold_map.read(buffer_snapshot.clone(), vec![]);
1293                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1294                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1295                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1296                    });
1297                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1298                    block_map.remove(block_ids_to_remove);
1299                }
1300                _ => {
1301                    buffer.update(cx, |buffer, cx| {
1302                        let edit_count = rng.gen_range(1..=5);
1303                        let subscription = buffer.subscribe();
1304                        buffer.randomly_edit(&mut rng, edit_count, cx);
1305                        buffer_snapshot = buffer.snapshot(cx);
1306                        buffer_edits.extend(subscription.consume());
1307                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1308                    });
1309                }
1310            }
1311
1312            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1313            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1314            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1315                wrap_map.sync(tabs_snapshot, tab_edits, cx)
1316            });
1317            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1318            assert_eq!(
1319                blocks_snapshot.transforms.summary().input_rows,
1320                wraps_snapshot.max_point().row() + 1
1321            );
1322            log::info!("blocks text: {:?}", blocks_snapshot.text());
1323
1324            let mut expected_blocks = Vec::new();
1325            expected_blocks.extend(custom_blocks.iter().map(|(id, block)| {
1326                let mut position = block.position.to_point(&buffer_snapshot);
1327                let column = wraps_snapshot.from_point(position, Bias::Left).column();
1328                match block.disposition {
1329                    BlockDisposition::Above => {
1330                        position.column = 0;
1331                    }
1332                    BlockDisposition::Below => {
1333                        position.column = buffer_snapshot.line_len(position.row);
1334                    }
1335                };
1336                let row = wraps_snapshot.from_point(position, Bias::Left).row();
1337                (row, block.disposition, Some(*id), block.height)
1338            }));
1339            expected_blocks.extend(buffer_snapshot.excerpt_boundaries_in_range(0..).map(
1340                |boundary| {
1341                    let position =
1342                        wraps_snapshot.from_point(Point::new(boundary.row, 0), Bias::Left);
1343                    (
1344                        position.row(),
1345                        BlockDisposition::Above,
1346                        None,
1347                        excerpt_header_height,
1348                    )
1349                },
1350            ));
1351            expected_blocks
1352                .sort_unstable_by_key(|(row, disposition, id, _)| (*row, *disposition, *id));
1353            let mut sorted_blocks_iter = expected_blocks.iter().peekable();
1354
1355            let input_buffer_rows = buffer_snapshot.buffer_rows(0).collect::<Vec<_>>();
1356            let mut expected_buffer_rows = Vec::new();
1357            let mut expected_text = String::new();
1358            let mut expected_block_positions = Vec::new();
1359            let input_text = wraps_snapshot.text();
1360            for (row, input_line) in input_text.split('\n').enumerate() {
1361                let row = row as u32;
1362                if row > 0 {
1363                    expected_text.push('\n');
1364                }
1365
1366                let buffer_row = input_buffer_rows[wraps_snapshot
1367                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1368                    .row as usize];
1369
1370                while let Some((block_row, disposition, id, height)) = sorted_blocks_iter.peek() {
1371                    if *block_row == row && *disposition == BlockDisposition::Above {
1372                        expected_block_positions
1373                            .push((expected_text.matches('\n').count() as u32, *id));
1374                        let text = "\n".repeat(*height as usize);
1375                        expected_text.push_str(&text);
1376                        for _ in 0..*height {
1377                            expected_buffer_rows.push(None);
1378                        }
1379                        sorted_blocks_iter.next();
1380                    } else {
1381                        break;
1382                    }
1383                }
1384
1385                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1386                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1387                expected_text.push_str(input_line);
1388
1389                while let Some((block_row, disposition, id, height)) = sorted_blocks_iter.peek() {
1390                    if *block_row == row && *disposition == BlockDisposition::Below {
1391                        expected_block_positions
1392                            .push((expected_text.matches('\n').count() as u32 + 1, *id));
1393                        let text = "\n".repeat(*height as usize);
1394                        expected_text.push_str(&text);
1395                        for _ in 0..*height {
1396                            expected_buffer_rows.push(None);
1397                        }
1398                        sorted_blocks_iter.next();
1399                    } else {
1400                        break;
1401                    }
1402                }
1403            }
1404
1405            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1406            let expected_row_count = expected_lines.len();
1407            for start_row in 0..expected_row_count {
1408                let expected_text = expected_lines[start_row..].join("\n");
1409                let actual_text = blocks_snapshot
1410                    .chunks(start_row as u32..expected_row_count as u32, false)
1411                    .map(|chunk| chunk.text)
1412                    .collect::<String>();
1413                assert_eq!(
1414                    actual_text, expected_text,
1415                    "incorrect text starting from row {}",
1416                    start_row
1417                );
1418                assert_eq!(
1419                    blocks_snapshot
1420                        .buffer_rows(start_row as u32)
1421                        .collect::<Vec<_>>(),
1422                    &expected_buffer_rows[start_row..]
1423                );
1424            }
1425
1426            assert_eq!(
1427                blocks_snapshot
1428                    .blocks_in_range(0..(expected_row_count as u32))
1429                    .map(|(row, block)| (row, block.as_custom().map(|(b, _)| b.id)))
1430                    .collect::<Vec<_>>(),
1431                expected_block_positions
1432            );
1433
1434            let mut expected_longest_rows = Vec::new();
1435            let mut longest_line_len = -1_isize;
1436            for (row, line) in expected_lines.iter().enumerate() {
1437                let row = row as u32;
1438
1439                assert_eq!(
1440                    blocks_snapshot.line_len(row),
1441                    line.len() as u32,
1442                    "invalid line len for row {}",
1443                    row
1444                );
1445
1446                let line_char_count = line.chars().count() as isize;
1447                match line_char_count.cmp(&longest_line_len) {
1448                    Ordering::Less => {}
1449                    Ordering::Equal => expected_longest_rows.push(row),
1450                    Ordering::Greater => {
1451                        longest_line_len = line_char_count;
1452                        expected_longest_rows.clear();
1453                        expected_longest_rows.push(row);
1454                    }
1455                }
1456            }
1457
1458            let longest_row = blocks_snapshot.longest_row();
1459            assert!(
1460                expected_longest_rows.contains(&longest_row),
1461                "incorrect longest row {}. expected {:?} with length {}",
1462                longest_row,
1463                expected_longest_rows,
1464                longest_line_len,
1465            );
1466
1467            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1468                let wrap_point = WrapPoint::new(row, 0);
1469                let block_point = blocks_snapshot.to_block_point(wrap_point);
1470                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1471            }
1472
1473            let mut block_point = BlockPoint::new(0, 0);
1474            for c in expected_text.chars() {
1475                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1476                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1477                assert_eq!(
1478                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1479                    left_point
1480                );
1481                assert_eq!(
1482                    left_buffer_point,
1483                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1484                    "{:?} is not valid in buffer coordinates",
1485                    left_point
1486                );
1487
1488                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1489                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1490                assert_eq!(
1491                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1492                    right_point
1493                );
1494                assert_eq!(
1495                    right_buffer_point,
1496                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1497                    "{:?} is not valid in buffer coordinates",
1498                    right_point
1499                );
1500
1501                if c == '\n' {
1502                    block_point.0 += Point::new(1, 0);
1503                } else {
1504                    block_point.column += c.len_utf8() as u32;
1505                }
1506            }
1507        }
1508    }
1509
1510    impl TransformBlock {
1511        fn as_custom(&self) -> Option<(&Block, u32)> {
1512            match self {
1513                TransformBlock::Custom { block, column } => Some((block, *column)),
1514                TransformBlock::ExcerptHeader { .. } => None,
1515            }
1516        }
1517    }
1518
1519    impl BlockSnapshot {
1520        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1521            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1522        }
1523    }
1524}