block_map.rs

   1use super::{
   2    wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot},
   3    TextHighlights,
   4};
   5use crate::{Anchor, Editor, ExcerptId, ExcerptRange, ToPoint as _};
   6use collections::{Bound, HashMap, HashSet};
   7use gpui::{fonts::HighlightStyle, AnyElement, ViewContext};
   8use language::{BufferSnapshot, Chunk, Patch, Point};
   9use parking_lot::Mutex;
  10use std::{
  11    cell::RefCell,
  12    cmp::{self, Ordering},
  13    fmt::Debug,
  14    ops::{Deref, DerefMut, Range},
  15    sync::{
  16        atomic::{AtomicUsize, Ordering::SeqCst},
  17        Arc,
  18    },
  19};
  20use sum_tree::{Bias, SumTree};
  21use text::Edit;
  22
  23const NEWLINES: &[u8] = &[b'\n'; u8::MAX as usize];
  24
  25pub struct BlockMap {
  26    next_block_id: AtomicUsize,
  27    wrap_snapshot: RefCell<WrapSnapshot>,
  28    blocks: Vec<Arc<Block>>,
  29    transforms: RefCell<SumTree<Transform>>,
  30    buffer_header_height: u8,
  31    excerpt_header_height: u8,
  32}
  33
  34pub struct BlockMapWriter<'a>(&'a mut BlockMap);
  35
  36pub struct BlockSnapshot {
  37    wrap_snapshot: WrapSnapshot,
  38    transforms: SumTree<Transform>,
  39}
  40
  41#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
  42pub struct BlockId(usize);
  43
  44#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  45pub struct BlockPoint(pub Point);
  46
  47#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  48struct BlockRow(u32);
  49
  50#[derive(Copy, Clone, Debug, Default, Eq, Ord, PartialOrd, PartialEq)]
  51struct WrapRow(u32);
  52
  53pub type RenderBlock = Arc<dyn Fn(&mut BlockContext) -> AnyElement<Editor>>;
  54
  55pub struct Block {
  56    id: BlockId,
  57    position: Anchor,
  58    height: u8,
  59    style: BlockStyle,
  60    render: Mutex<RenderBlock>,
  61    disposition: BlockDisposition,
  62}
  63
  64#[derive(Clone)]
  65pub struct BlockProperties<P>
  66where
  67    P: Clone,
  68{
  69    pub position: P,
  70    pub height: u8,
  71    pub style: BlockStyle,
  72    pub render: Arc<dyn Fn(&mut BlockContext) -> AnyElement<Editor>>,
  73    pub disposition: BlockDisposition,
  74}
  75
  76#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd)]
  77pub enum BlockStyle {
  78    Fixed,
  79    Flex,
  80    Sticky,
  81}
  82
  83pub struct BlockContext<'a, 'b, 'c> {
  84    pub view_context: &'c mut ViewContext<'a, 'b, Editor>,
  85    pub anchor_x: f32,
  86    pub scroll_x: f32,
  87    pub gutter_width: f32,
  88    pub gutter_padding: f32,
  89    pub em_width: f32,
  90    pub line_height: f32,
  91    pub block_id: usize,
  92}
  93
  94#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  95pub enum BlockDisposition {
  96    Above,
  97    Below,
  98}
  99
 100#[derive(Clone, Debug)]
 101struct Transform {
 102    summary: TransformSummary,
 103    block: Option<TransformBlock>,
 104}
 105
 106#[allow(clippy::large_enum_variant)]
 107#[derive(Clone)]
 108pub enum TransformBlock {
 109    Custom(Arc<Block>),
 110    ExcerptHeader {
 111        id: ExcerptId,
 112        buffer: BufferSnapshot,
 113        range: ExcerptRange<text::Anchor>,
 114        height: u8,
 115        starts_new_buffer: bool,
 116    },
 117}
 118
 119impl TransformBlock {
 120    fn disposition(&self) -> BlockDisposition {
 121        match self {
 122            TransformBlock::Custom(block) => block.disposition,
 123            TransformBlock::ExcerptHeader { .. } => BlockDisposition::Above,
 124        }
 125    }
 126
 127    pub fn height(&self) -> u8 {
 128        match self {
 129            TransformBlock::Custom(block) => block.height,
 130            TransformBlock::ExcerptHeader { height, .. } => *height,
 131        }
 132    }
 133}
 134
 135impl Debug for TransformBlock {
 136    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 137        match self {
 138            Self::Custom(block) => f.debug_struct("Custom").field("block", block).finish(),
 139            Self::ExcerptHeader { buffer, .. } => f
 140                .debug_struct("ExcerptHeader")
 141                .field("path", &buffer.file().map(|f| f.path()))
 142                .finish(),
 143        }
 144    }
 145}
 146
 147#[derive(Clone, Debug, Default)]
 148struct TransformSummary {
 149    input_rows: u32,
 150    output_rows: u32,
 151}
 152
 153pub struct BlockChunks<'a> {
 154    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 155    input_chunks: wrap_map::WrapChunks<'a>,
 156    input_chunk: Chunk<'a>,
 157    output_row: u32,
 158    max_output_row: u32,
 159}
 160
 161#[derive(Clone)]
 162pub struct BlockBufferRows<'a> {
 163    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 164    input_buffer_rows: wrap_map::WrapBufferRows<'a>,
 165    output_row: u32,
 166    started: bool,
 167}
 168
 169impl BlockMap {
 170    pub fn new(
 171        wrap_snapshot: WrapSnapshot,
 172        buffer_header_height: u8,
 173        excerpt_header_height: u8,
 174    ) -> Self {
 175        let row_count = wrap_snapshot.max_point().row() + 1;
 176        let map = Self {
 177            next_block_id: AtomicUsize::new(0),
 178            blocks: Vec::new(),
 179            transforms: RefCell::new(SumTree::from_item(Transform::isomorphic(row_count), &())),
 180            wrap_snapshot: RefCell::new(wrap_snapshot.clone()),
 181            buffer_header_height,
 182            excerpt_header_height,
 183        };
 184        map.sync(
 185            &wrap_snapshot,
 186            Patch::new(vec![Edit {
 187                old: 0..row_count,
 188                new: 0..row_count,
 189            }]),
 190        );
 191        map
 192    }
 193
 194    pub fn read(&self, wrap_snapshot: WrapSnapshot, edits: Patch<u32>) -> BlockSnapshot {
 195        self.sync(&wrap_snapshot, edits);
 196        *self.wrap_snapshot.borrow_mut() = wrap_snapshot.clone();
 197        BlockSnapshot {
 198            wrap_snapshot,
 199            transforms: self.transforms.borrow().clone(),
 200        }
 201    }
 202
 203    pub fn write(&mut self, wrap_snapshot: WrapSnapshot, edits: Patch<u32>) -> BlockMapWriter {
 204        self.sync(&wrap_snapshot, edits);
 205        *self.wrap_snapshot.borrow_mut() = wrap_snapshot;
 206        BlockMapWriter(self)
 207    }
 208
 209    fn sync(&self, wrap_snapshot: &WrapSnapshot, mut edits: Patch<u32>) {
 210        let buffer = wrap_snapshot.buffer_snapshot();
 211
 212        // Handle changing the last excerpt if it is empty.
 213        if buffer.trailing_excerpt_update_count()
 214            != self
 215                .wrap_snapshot
 216                .borrow()
 217                .buffer_snapshot()
 218                .trailing_excerpt_update_count()
 219        {
 220            let max_point = wrap_snapshot.max_point();
 221            let edit_start = wrap_snapshot.prev_row_boundary(max_point);
 222            let edit_end = max_point.row() + 1;
 223            edits = edits.compose([WrapEdit {
 224                old: edit_start..edit_end,
 225                new: edit_start..edit_end,
 226            }]);
 227        }
 228
 229        let edits = edits.into_inner();
 230        if edits.is_empty() {
 231            return;
 232        }
 233
 234        let mut transforms = self.transforms.borrow_mut();
 235        let mut new_transforms = SumTree::new();
 236        let old_row_count = transforms.summary().input_rows;
 237        let new_row_count = wrap_snapshot.max_point().row() + 1;
 238        let mut cursor = transforms.cursor::<WrapRow>();
 239        let mut last_block_ix = 0;
 240        let mut blocks_in_edit = Vec::new();
 241        let mut edits = edits.into_iter().peekable();
 242
 243        while let Some(edit) = edits.next() {
 244            // Preserve any old transforms that precede this edit.
 245            let old_start = WrapRow(edit.old.start);
 246            let new_start = WrapRow(edit.new.start);
 247            new_transforms.append(cursor.slice(&old_start, Bias::Left, &()), &());
 248            if let Some(transform) = cursor.item() {
 249                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 250                    new_transforms.push(transform.clone(), &());
 251                    cursor.next(&());
 252                    while let Some(transform) = cursor.item() {
 253                        if transform
 254                            .block
 255                            .as_ref()
 256                            .map_or(false, |b| b.disposition().is_below())
 257                        {
 258                            new_transforms.push(transform.clone(), &());
 259                            cursor.next(&());
 260                        } else {
 261                            break;
 262                        }
 263                    }
 264                }
 265            }
 266
 267            // Preserve any portion of an old transform that precedes this edit.
 268            let extent_before_edit = old_start.0 - cursor.start().0;
 269            push_isomorphic(&mut new_transforms, extent_before_edit);
 270
 271            // Skip over any old transforms that intersect this edit.
 272            let mut old_end = WrapRow(edit.old.end);
 273            let mut new_end = WrapRow(edit.new.end);
 274            cursor.seek(&old_end, Bias::Left, &());
 275            cursor.next(&());
 276            if old_end == *cursor.start() {
 277                while let Some(transform) = cursor.item() {
 278                    if transform
 279                        .block
 280                        .as_ref()
 281                        .map_or(false, |b| b.disposition().is_below())
 282                    {
 283                        cursor.next(&());
 284                    } else {
 285                        break;
 286                    }
 287                }
 288            }
 289
 290            // Combine this edit with any subsequent edits that intersect the same transform.
 291            while let Some(next_edit) = edits.peek() {
 292                if next_edit.old.start <= cursor.start().0 {
 293                    old_end = WrapRow(next_edit.old.end);
 294                    new_end = WrapRow(next_edit.new.end);
 295                    cursor.seek(&old_end, Bias::Left, &());
 296                    cursor.next(&());
 297                    if old_end == *cursor.start() {
 298                        while let Some(transform) = cursor.item() {
 299                            if transform
 300                                .block
 301                                .as_ref()
 302                                .map_or(false, |b| b.disposition().is_below())
 303                            {
 304                                cursor.next(&());
 305                            } else {
 306                                break;
 307                            }
 308                        }
 309                    }
 310                    edits.next();
 311                } else {
 312                    break;
 313                }
 314            }
 315
 316            // Find the blocks within this edited region.
 317            let new_buffer_start =
 318                wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 319            let start_bound = Bound::Included(new_buffer_start);
 320            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 321                probe
 322                    .position
 323                    .to_point(buffer)
 324                    .cmp(&new_buffer_start)
 325                    .then(Ordering::Greater)
 326            }) {
 327                Ok(ix) | Err(ix) => last_block_ix + ix,
 328            };
 329
 330            let end_bound;
 331            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 332                end_bound = Bound::Unbounded;
 333                self.blocks.len()
 334            } else {
 335                let new_buffer_end =
 336                    wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 337                end_bound = Bound::Excluded(new_buffer_end);
 338                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 339                    probe
 340                        .position
 341                        .to_point(buffer)
 342                        .cmp(&new_buffer_end)
 343                        .then(Ordering::Greater)
 344                }) {
 345                    Ok(ix) | Err(ix) => start_block_ix + ix,
 346                }
 347            };
 348            last_block_ix = end_block_ix;
 349
 350            debug_assert!(blocks_in_edit.is_empty());
 351            blocks_in_edit.extend(
 352                self.blocks[start_block_ix..end_block_ix]
 353                    .iter()
 354                    .map(|block| {
 355                        let mut position = block.position.to_point(buffer);
 356                        match block.disposition {
 357                            BlockDisposition::Above => position.column = 0,
 358                            BlockDisposition::Below => {
 359                                position.column = buffer.line_len(position.row)
 360                            }
 361                        }
 362                        let position = wrap_snapshot.make_wrap_point(position, Bias::Left);
 363                        (position.row(), TransformBlock::Custom(block.clone()))
 364                    }),
 365            );
 366            blocks_in_edit.extend(
 367                buffer
 368                    .excerpt_boundaries_in_range((start_bound, end_bound))
 369                    .map(|excerpt_boundary| {
 370                        (
 371                            wrap_snapshot
 372                                .make_wrap_point(Point::new(excerpt_boundary.row, 0), Bias::Left)
 373                                .row(),
 374                            TransformBlock::ExcerptHeader {
 375                                id: excerpt_boundary.id,
 376                                buffer: excerpt_boundary.buffer,
 377                                range: excerpt_boundary.range,
 378                                height: if excerpt_boundary.starts_new_buffer {
 379                                    self.buffer_header_height
 380                                } else {
 381                                    self.excerpt_header_height
 382                                },
 383                                starts_new_buffer: excerpt_boundary.starts_new_buffer,
 384                            },
 385                        )
 386                    }),
 387            );
 388
 389            // Place excerpt headers above custom blocks on the same row.
 390            blocks_in_edit.sort_unstable_by(|(row_a, block_a), (row_b, block_b)| {
 391                row_a.cmp(row_b).then_with(|| match (block_a, block_b) {
 392                    (
 393                        TransformBlock::ExcerptHeader { .. },
 394                        TransformBlock::ExcerptHeader { .. },
 395                    ) => Ordering::Equal,
 396                    (TransformBlock::ExcerptHeader { .. }, _) => Ordering::Less,
 397                    (_, TransformBlock::ExcerptHeader { .. }) => Ordering::Greater,
 398                    (TransformBlock::Custom(block_a), TransformBlock::Custom(block_b)) => block_a
 399                        .disposition
 400                        .cmp(&block_b.disposition)
 401                        .then_with(|| block_a.id.cmp(&block_b.id)),
 402                })
 403            });
 404
 405            // For each of these blocks, insert a new isomorphic transform preceding the block,
 406            // and then insert the block itself.
 407            for (block_row, block) in blocks_in_edit.drain(..) {
 408                let insertion_row = match block.disposition() {
 409                    BlockDisposition::Above => block_row,
 410                    BlockDisposition::Below => block_row + 1,
 411                };
 412                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 413                push_isomorphic(&mut new_transforms, extent_before_block);
 414                new_transforms.push(Transform::block(block), &());
 415            }
 416
 417            old_end = WrapRow(old_end.0.min(old_row_count));
 418            new_end = WrapRow(new_end.0.min(new_row_count));
 419
 420            // Insert an isomorphic transform after the final block.
 421            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 422            push_isomorphic(&mut new_transforms, extent_after_last_block);
 423
 424            // Preserve any portion of the old transform after this edit.
 425            let extent_after_edit = cursor.start().0 - old_end.0;
 426            push_isomorphic(&mut new_transforms, extent_after_edit);
 427        }
 428
 429        new_transforms.append(cursor.suffix(&()), &());
 430        debug_assert_eq!(
 431            new_transforms.summary().input_rows,
 432            wrap_snapshot.max_point().row() + 1
 433        );
 434
 435        drop(cursor);
 436        *transforms = new_transforms;
 437    }
 438
 439    pub fn replace(&mut self, mut renderers: HashMap<BlockId, RenderBlock>) {
 440        for block in &self.blocks {
 441            if let Some(render) = renderers.remove(&block.id) {
 442                *block.render.lock() = render;
 443            }
 444        }
 445    }
 446}
 447
 448fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 449    if rows == 0 {
 450        return;
 451    }
 452
 453    let mut extent = Some(rows);
 454    tree.update_last(
 455        |last_transform| {
 456            if last_transform.is_isomorphic() {
 457                let extent = extent.take().unwrap();
 458                last_transform.summary.input_rows += extent;
 459                last_transform.summary.output_rows += extent;
 460            }
 461        },
 462        &(),
 463    );
 464    if let Some(extent) = extent {
 465        tree.push(Transform::isomorphic(extent), &());
 466    }
 467}
 468
 469impl BlockPoint {
 470    pub fn new(row: u32, column: u32) -> Self {
 471        Self(Point::new(row, column))
 472    }
 473}
 474
 475impl Deref for BlockPoint {
 476    type Target = Point;
 477
 478    fn deref(&self) -> &Self::Target {
 479        &self.0
 480    }
 481}
 482
 483impl std::ops::DerefMut for BlockPoint {
 484    fn deref_mut(&mut self) -> &mut Self::Target {
 485        &mut self.0
 486    }
 487}
 488
 489impl<'a> BlockMapWriter<'a> {
 490    pub fn insert(
 491        &mut self,
 492        blocks: impl IntoIterator<Item = BlockProperties<Anchor>>,
 493    ) -> Vec<BlockId> {
 494        let mut ids = Vec::new();
 495        let mut edits = Patch::default();
 496        let wrap_snapshot = &*self.0.wrap_snapshot.borrow();
 497        let buffer = wrap_snapshot.buffer_snapshot();
 498
 499        for block in blocks {
 500            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 501            ids.push(id);
 502
 503            let position = block.position;
 504            let point = position.to_point(buffer);
 505            let wrap_row = wrap_snapshot
 506                .make_wrap_point(Point::new(point.row, 0), Bias::Left)
 507                .row();
 508            let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 509            let end_row = wrap_snapshot
 510                .next_row_boundary(WrapPoint::new(wrap_row, 0))
 511                .unwrap_or(wrap_snapshot.max_point().row() + 1);
 512
 513            let block_ix = match self
 514                .0
 515                .blocks
 516                .binary_search_by(|probe| probe.position.cmp(&position, buffer))
 517            {
 518                Ok(ix) | Err(ix) => ix,
 519            };
 520            self.0.blocks.insert(
 521                block_ix,
 522                Arc::new(Block {
 523                    id,
 524                    position,
 525                    height: block.height,
 526                    render: Mutex::new(block.render),
 527                    disposition: block.disposition,
 528                    style: block.style,
 529                }),
 530            );
 531
 532            edits = edits.compose([Edit {
 533                old: start_row..end_row,
 534                new: start_row..end_row,
 535            }]);
 536        }
 537
 538        self.0.sync(wrap_snapshot, edits);
 539        ids
 540    }
 541
 542    pub fn remove(&mut self, block_ids: HashSet<BlockId>) {
 543        let wrap_snapshot = &*self.0.wrap_snapshot.borrow();
 544        let buffer = wrap_snapshot.buffer_snapshot();
 545        let mut edits = Patch::default();
 546        let mut last_block_buffer_row = None;
 547        self.0.blocks.retain(|block| {
 548            if block_ids.contains(&block.id) {
 549                let buffer_row = block.position.to_point(buffer).row;
 550                if last_block_buffer_row != Some(buffer_row) {
 551                    last_block_buffer_row = Some(buffer_row);
 552                    let wrap_row = wrap_snapshot
 553                        .make_wrap_point(Point::new(buffer_row, 0), Bias::Left)
 554                        .row();
 555                    let start_row = wrap_snapshot.prev_row_boundary(WrapPoint::new(wrap_row, 0));
 556                    let end_row = wrap_snapshot
 557                        .next_row_boundary(WrapPoint::new(wrap_row, 0))
 558                        .unwrap_or(wrap_snapshot.max_point().row() + 1);
 559                    edits.push(Edit {
 560                        old: start_row..end_row,
 561                        new: start_row..end_row,
 562                    })
 563                }
 564                false
 565            } else {
 566                true
 567            }
 568        });
 569        self.0.sync(wrap_snapshot, edits);
 570    }
 571}
 572
 573impl BlockSnapshot {
 574    #[cfg(test)]
 575    pub fn text(&self) -> String {
 576        self.chunks(
 577            0..self.transforms.summary().output_rows,
 578            false,
 579            None,
 580            None,
 581            None,
 582        )
 583        .map(|chunk| chunk.text)
 584        .collect()
 585    }
 586
 587    pub fn chunks<'a>(
 588        &'a self,
 589        rows: Range<u32>,
 590        language_aware: bool,
 591        text_highlights: Option<&'a TextHighlights>,
 592        hint_highlights: Option<HighlightStyle>,
 593        suggestion_highlights: Option<HighlightStyle>,
 594    ) -> BlockChunks<'a> {
 595        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 596        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 597        let input_end = {
 598            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 599            let overshoot = if cursor
 600                .item()
 601                .map_or(false, |transform| transform.is_isomorphic())
 602            {
 603                rows.end - cursor.start().0 .0
 604            } else {
 605                0
 606            };
 607            cursor.start().1 .0 + overshoot
 608        };
 609        let input_start = {
 610            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 611            let overshoot = if cursor
 612                .item()
 613                .map_or(false, |transform| transform.is_isomorphic())
 614            {
 615                rows.start - cursor.start().0 .0
 616            } else {
 617                0
 618            };
 619            cursor.start().1 .0 + overshoot
 620        };
 621        BlockChunks {
 622            input_chunks: self.wrap_snapshot.chunks(
 623                input_start..input_end,
 624                language_aware,
 625                text_highlights,
 626                hint_highlights,
 627                suggestion_highlights,
 628            ),
 629            input_chunk: Default::default(),
 630            transforms: cursor,
 631            output_row: rows.start,
 632            max_output_row,
 633        }
 634    }
 635
 636    pub fn buffer_rows(&self, start_row: u32) -> BlockBufferRows {
 637        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 638        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 639        let (output_start, input_start) = cursor.start();
 640        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 641            start_row - output_start.0
 642        } else {
 643            0
 644        };
 645        let input_start_row = input_start.0 + overshoot;
 646        BlockBufferRows {
 647            transforms: cursor,
 648            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 649            output_row: start_row,
 650            started: false,
 651        }
 652    }
 653
 654    pub fn blocks_in_range(
 655        &self,
 656        rows: Range<u32>,
 657    ) -> impl Iterator<Item = (u32, &TransformBlock)> {
 658        let mut cursor = self.transforms.cursor::<BlockRow>();
 659        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 660        std::iter::from_fn(move || {
 661            while let Some(transform) = cursor.item() {
 662                let start_row = cursor.start().0;
 663                if start_row >= rows.end {
 664                    break;
 665                }
 666                if let Some(block) = &transform.block {
 667                    cursor.next(&());
 668                    return Some((start_row, block));
 669                } else {
 670                    cursor.next(&());
 671                }
 672            }
 673            None
 674        })
 675    }
 676
 677    pub fn max_point(&self) -> BlockPoint {
 678        let row = self.transforms.summary().output_rows - 1;
 679        BlockPoint::new(row, self.line_len(row))
 680    }
 681
 682    pub fn longest_row(&self) -> u32 {
 683        let input_row = self.wrap_snapshot.longest_row();
 684        self.to_block_point(WrapPoint::new(input_row, 0)).row
 685    }
 686
 687    pub fn line_len(&self, row: u32) -> u32 {
 688        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 689        cursor.seek(&BlockRow(row), Bias::Right, &());
 690        if let Some(transform) = cursor.item() {
 691            let (output_start, input_start) = cursor.start();
 692            let overshoot = row - output_start.0;
 693            if transform.block.is_some() {
 694                0
 695            } else {
 696                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 697            }
 698        } else {
 699            panic!("row out of range");
 700        }
 701    }
 702
 703    pub fn is_block_line(&self, row: u32) -> bool {
 704        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 705        cursor.seek(&BlockRow(row), Bias::Right, &());
 706        cursor.item().map_or(false, |t| t.block.is_some())
 707    }
 708
 709    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 710        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 711        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 712
 713        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 714        let mut search_left =
 715            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 716        let mut reversed = false;
 717
 718        loop {
 719            if let Some(transform) = cursor.item() {
 720                if transform.is_isomorphic() {
 721                    let (output_start_row, input_start_row) = cursor.start();
 722                    let (output_end_row, input_end_row) = cursor.end(&());
 723                    let output_start = Point::new(output_start_row.0, 0);
 724                    let input_start = Point::new(input_start_row.0, 0);
 725                    let input_end = Point::new(input_end_row.0, 0);
 726                    let input_point = if point.row >= output_end_row.0 {
 727                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 728                        self.wrap_snapshot
 729                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 730                    } else {
 731                        let output_overshoot = point.0.saturating_sub(output_start);
 732                        self.wrap_snapshot
 733                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 734                    };
 735
 736                    if (input_start..input_end).contains(&input_point.0) {
 737                        let input_overshoot = input_point.0.saturating_sub(input_start);
 738                        return BlockPoint(output_start + input_overshoot);
 739                    }
 740                }
 741
 742                if search_left {
 743                    cursor.prev(&());
 744                } else {
 745                    cursor.next(&());
 746                }
 747            } else if reversed {
 748                return self.max_point();
 749            } else {
 750                reversed = true;
 751                search_left = !search_left;
 752                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 753            }
 754        }
 755    }
 756
 757    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 758        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 759        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 760        if let Some(transform) = cursor.item() {
 761            debug_assert!(transform.is_isomorphic());
 762        } else {
 763            return self.max_point();
 764        }
 765
 766        let (input_start_row, output_start_row) = cursor.start();
 767        let input_start = Point::new(input_start_row.0, 0);
 768        let output_start = Point::new(output_start_row.0, 0);
 769        let input_overshoot = wrap_point.0 - input_start;
 770        BlockPoint(output_start + input_overshoot)
 771    }
 772
 773    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 774        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 775        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 776        if let Some(transform) = cursor.item() {
 777            match transform.block.as_ref().map(|b| b.disposition()) {
 778                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 779                Some(BlockDisposition::Below) => {
 780                    let wrap_row = cursor.start().1 .0 - 1;
 781                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 782                }
 783                None => {
 784                    let overshoot = block_point.row - cursor.start().0 .0;
 785                    let wrap_row = cursor.start().1 .0 + overshoot;
 786                    WrapPoint::new(wrap_row, block_point.column)
 787                }
 788            }
 789        } else {
 790            self.wrap_snapshot.max_point()
 791        }
 792    }
 793}
 794
 795impl Transform {
 796    fn isomorphic(rows: u32) -> Self {
 797        Self {
 798            summary: TransformSummary {
 799                input_rows: rows,
 800                output_rows: rows,
 801            },
 802            block: None,
 803        }
 804    }
 805
 806    fn block(block: TransformBlock) -> Self {
 807        Self {
 808            summary: TransformSummary {
 809                input_rows: 0,
 810                output_rows: block.height() as u32,
 811            },
 812            block: Some(block),
 813        }
 814    }
 815
 816    fn is_isomorphic(&self) -> bool {
 817        self.block.is_none()
 818    }
 819}
 820
 821impl<'a> Iterator for BlockChunks<'a> {
 822    type Item = Chunk<'a>;
 823
 824    fn next(&mut self) -> Option<Self::Item> {
 825        if self.output_row >= self.max_output_row {
 826            return None;
 827        }
 828
 829        let transform = self.transforms.item()?;
 830        if transform.block.is_some() {
 831            let block_start = self.transforms.start().0 .0;
 832            let mut block_end = self.transforms.end(&()).0 .0;
 833            self.transforms.next(&());
 834            if self.transforms.item().is_none() {
 835                block_end -= 1;
 836            }
 837
 838            let start_in_block = self.output_row - block_start;
 839            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 840            let line_count = end_in_block - start_in_block;
 841            self.output_row += line_count;
 842
 843            return Some(Chunk {
 844                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 845                ..Default::default()
 846            });
 847        }
 848
 849        if self.input_chunk.text.is_empty() {
 850            if let Some(input_chunk) = self.input_chunks.next() {
 851                self.input_chunk = input_chunk;
 852            } else {
 853                self.output_row += 1;
 854                if self.output_row < self.max_output_row {
 855                    self.transforms.next(&());
 856                    return Some(Chunk {
 857                        text: "\n",
 858                        ..Default::default()
 859                    });
 860                } else {
 861                    return None;
 862                }
 863            }
 864        }
 865
 866        let transform_end = self.transforms.end(&()).0 .0;
 867        let (prefix_rows, prefix_bytes) =
 868            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 869        self.output_row += prefix_rows;
 870        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 871        self.input_chunk.text = suffix;
 872        if self.output_row == transform_end {
 873            self.transforms.next(&());
 874        }
 875
 876        Some(Chunk {
 877            text: prefix,
 878            ..self.input_chunk
 879        })
 880    }
 881}
 882
 883impl<'a> Iterator for BlockBufferRows<'a> {
 884    type Item = Option<u32>;
 885
 886    fn next(&mut self) -> Option<Self::Item> {
 887        if self.started {
 888            self.output_row += 1;
 889        } else {
 890            self.started = true;
 891        }
 892
 893        if self.output_row >= self.transforms.end(&()).0 .0 {
 894            self.transforms.next(&());
 895        }
 896
 897        let transform = self.transforms.item()?;
 898        if transform.block.is_some() {
 899            Some(None)
 900        } else {
 901            Some(self.input_buffer_rows.next().unwrap())
 902        }
 903    }
 904}
 905
 906impl sum_tree::Item for Transform {
 907    type Summary = TransformSummary;
 908
 909    fn summary(&self) -> Self::Summary {
 910        self.summary.clone()
 911    }
 912}
 913
 914impl sum_tree::Summary for TransformSummary {
 915    type Context = ();
 916
 917    fn add_summary(&mut self, summary: &Self, _: &()) {
 918        self.input_rows += summary.input_rows;
 919        self.output_rows += summary.output_rows;
 920    }
 921}
 922
 923impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 924    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 925        self.0 += summary.input_rows;
 926    }
 927}
 928
 929impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 930    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 931        self.0 += summary.output_rows;
 932    }
 933}
 934
 935impl BlockDisposition {
 936    fn is_below(&self) -> bool {
 937        matches!(self, BlockDisposition::Below)
 938    }
 939}
 940
 941impl<'a, 'b, 'c> Deref for BlockContext<'a, 'b, 'c> {
 942    type Target = ViewContext<'a, 'b, Editor>;
 943
 944    fn deref(&self) -> &Self::Target {
 945        self.view_context
 946    }
 947}
 948
 949impl DerefMut for BlockContext<'_, '_, '_> {
 950    fn deref_mut(&mut self) -> &mut Self::Target {
 951        self.view_context
 952    }
 953}
 954
 955impl Block {
 956    pub fn render(&self, cx: &mut BlockContext) -> AnyElement<Editor> {
 957        self.render.lock()(cx)
 958    }
 959
 960    pub fn position(&self) -> &Anchor {
 961        &self.position
 962    }
 963
 964    pub fn style(&self) -> BlockStyle {
 965        self.style
 966    }
 967}
 968
 969impl Debug for Block {
 970    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 971        f.debug_struct("Block")
 972            .field("id", &self.id)
 973            .field("position", &self.position)
 974            .field("disposition", &self.disposition)
 975            .finish()
 976    }
 977}
 978
 979// Count the number of bytes prior to a target point. If the string doesn't contain the target
 980// point, return its total extent. Otherwise return the target point itself.
 981fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 982    let mut row = 0;
 983    let mut offset = 0;
 984    for (ix, line) in s.split('\n').enumerate() {
 985        if ix > 0 {
 986            row += 1;
 987            offset += 1;
 988        }
 989        if row >= target {
 990            break;
 991        }
 992        offset += line.len() as usize;
 993    }
 994    (row, offset)
 995}
 996
 997#[cfg(test)]
 998mod tests {
 999    use super::*;
1000    use crate::display_map::inlay_map::InlayMap;
1001    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
1002    use crate::multi_buffer::MultiBuffer;
1003    use gpui::{elements::Empty, Element};
1004    use rand::prelude::*;
1005    use settings::SettingsStore;
1006    use std::env;
1007    use util::RandomCharIter;
1008
1009    #[gpui::test]
1010    fn test_offset_for_row() {
1011        assert_eq!(offset_for_row("", 0), (0, 0));
1012        assert_eq!(offset_for_row("", 1), (0, 0));
1013        assert_eq!(offset_for_row("abcd", 0), (0, 0));
1014        assert_eq!(offset_for_row("abcd", 1), (0, 4));
1015        assert_eq!(offset_for_row("\n", 0), (0, 0));
1016        assert_eq!(offset_for_row("\n", 1), (1, 1));
1017        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
1018        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
1019        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
1020        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
1021    }
1022
1023    #[gpui::test]
1024    fn test_basic_blocks(cx: &mut gpui::AppContext) {
1025        init_test(cx);
1026
1027        let family_id = cx
1028            .font_cache()
1029            .load_family(&["Helvetica"], &Default::default())
1030            .unwrap();
1031        let font_id = cx
1032            .font_cache()
1033            .select_font(family_id, &Default::default())
1034            .unwrap();
1035
1036        let text = "aaa\nbbb\nccc\nddd";
1037
1038        let buffer = MultiBuffer::build_simple(text, cx);
1039        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1040        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1041        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1042        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1043        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 1.try_into().unwrap());
1044        let (wrap_map, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, None, cx);
1045        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1046
1047        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1048        let block_ids = writer.insert(vec![
1049            BlockProperties {
1050                style: BlockStyle::Fixed,
1051                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
1052                height: 1,
1053                disposition: BlockDisposition::Above,
1054                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1055            },
1056            BlockProperties {
1057                style: BlockStyle::Fixed,
1058                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
1059                height: 2,
1060                disposition: BlockDisposition::Above,
1061                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1062            },
1063            BlockProperties {
1064                style: BlockStyle::Fixed,
1065                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
1066                height: 3,
1067                disposition: BlockDisposition::Below,
1068                render: Arc::new(|_| Empty::new().into_any_named("block 3")),
1069            },
1070        ]);
1071
1072        let snapshot = block_map.read(wraps_snapshot, Default::default());
1073        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1074
1075        let blocks = snapshot
1076            .blocks_in_range(0..8)
1077            .map(|(start_row, block)| {
1078                let block = block.as_custom().unwrap();
1079                (start_row..start_row + block.height as u32, block.id)
1080            })
1081            .collect::<Vec<_>>();
1082
1083        // When multiple blocks are on the same line, the newer blocks appear first.
1084        assert_eq!(
1085            blocks,
1086            &[
1087                (1..2, block_ids[0]),
1088                (2..4, block_ids[1]),
1089                (7..10, block_ids[2]),
1090            ]
1091        );
1092
1093        assert_eq!(
1094            snapshot.to_block_point(WrapPoint::new(0, 3)),
1095            BlockPoint::new(0, 3)
1096        );
1097        assert_eq!(
1098            snapshot.to_block_point(WrapPoint::new(1, 0)),
1099            BlockPoint::new(4, 0)
1100        );
1101        assert_eq!(
1102            snapshot.to_block_point(WrapPoint::new(3, 3)),
1103            BlockPoint::new(6, 3)
1104        );
1105
1106        assert_eq!(
1107            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
1108            WrapPoint::new(0, 3)
1109        );
1110        assert_eq!(
1111            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
1112            WrapPoint::new(1, 0)
1113        );
1114        assert_eq!(
1115            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
1116            WrapPoint::new(1, 0)
1117        );
1118        assert_eq!(
1119            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
1120            WrapPoint::new(3, 3)
1121        );
1122
1123        assert_eq!(
1124            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
1125            BlockPoint::new(0, 3)
1126        );
1127        assert_eq!(
1128            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1129            BlockPoint::new(4, 0)
1130        );
1131        assert_eq!(
1132            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1133            BlockPoint::new(0, 3)
1134        );
1135        assert_eq!(
1136            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1137            BlockPoint::new(4, 0)
1138        );
1139        assert_eq!(
1140            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1141            BlockPoint::new(4, 0)
1142        );
1143        assert_eq!(
1144            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1145            BlockPoint::new(4, 0)
1146        );
1147        assert_eq!(
1148            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1149            BlockPoint::new(6, 3)
1150        );
1151        assert_eq!(
1152            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1153            BlockPoint::new(6, 3)
1154        );
1155        assert_eq!(
1156            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1157            BlockPoint::new(6, 3)
1158        );
1159        assert_eq!(
1160            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1161            BlockPoint::new(6, 3)
1162        );
1163
1164        assert_eq!(
1165            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1166            &[
1167                Some(0),
1168                None,
1169                None,
1170                None,
1171                Some(1),
1172                Some(2),
1173                Some(3),
1174                None,
1175                None,
1176                None
1177            ]
1178        );
1179
1180        // Insert a line break, separating two block decorations into separate lines.
1181        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1182            buffer.edit([(Point::new(1, 1)..Point::new(1, 1), "!!!\n")], None, cx);
1183            buffer.snapshot(cx)
1184        });
1185
1186        let (inlay_snapshot, inlay_edits) =
1187            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1188        let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1189        let (tab_snapshot, tab_edits) =
1190            tab_map.sync(fold_snapshot, fold_edits, 4.try_into().unwrap());
1191        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1192            wrap_map.sync(tab_snapshot, tab_edits, cx)
1193        });
1194        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1195        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1196    }
1197
1198    #[gpui::test]
1199    fn test_blocks_on_wrapped_lines(cx: &mut gpui::AppContext) {
1200        init_test(cx);
1201
1202        let family_id = cx
1203            .font_cache()
1204            .load_family(&["Helvetica"], &Default::default())
1205            .unwrap();
1206        let font_id = cx
1207            .font_cache()
1208            .select_font(family_id, &Default::default())
1209            .unwrap();
1210
1211        let text = "one two three\nfour five six\nseven eight";
1212
1213        let buffer = MultiBuffer::build_simple(text, cx);
1214        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1215        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1216        let (_, fold_snapshot) = FoldMap::new(inlay_snapshot);
1217        let (_, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1218        let (_, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, Some(60.), cx);
1219        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1220
1221        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1222        writer.insert(vec![
1223            BlockProperties {
1224                style: BlockStyle::Fixed,
1225                position: buffer_snapshot.anchor_after(Point::new(1, 12)),
1226                disposition: BlockDisposition::Above,
1227                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1228                height: 1,
1229            },
1230            BlockProperties {
1231                style: BlockStyle::Fixed,
1232                position: buffer_snapshot.anchor_after(Point::new(1, 1)),
1233                disposition: BlockDisposition::Below,
1234                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1235                height: 1,
1236            },
1237        ]);
1238
1239        // Blocks with an 'above' disposition go above their corresponding buffer line.
1240        // Blocks with a 'below' disposition go below their corresponding buffer line.
1241        let snapshot = block_map.read(wraps_snapshot, Default::default());
1242        assert_eq!(
1243            snapshot.text(),
1244            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1245        );
1246    }
1247
1248    #[gpui::test(iterations = 100)]
1249    fn test_random_blocks(cx: &mut gpui::AppContext, mut rng: StdRng) {
1250        init_test(cx);
1251
1252        let operations = env::var("OPERATIONS")
1253            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1254            .unwrap_or(10);
1255
1256        let wrap_width = if rng.gen_bool(0.2) {
1257            None
1258        } else {
1259            Some(rng.gen_range(0.0..=100.0))
1260        };
1261        let tab_size = 1.try_into().unwrap();
1262        let family_id = cx
1263            .font_cache()
1264            .load_family(&["Helvetica"], &Default::default())
1265            .unwrap();
1266        let font_id = cx
1267            .font_cache()
1268            .select_font(family_id, &Default::default())
1269            .unwrap();
1270        let font_size = 14.0;
1271        let buffer_start_header_height = rng.gen_range(1..=5);
1272        let excerpt_header_height = rng.gen_range(1..=5);
1273
1274        log::info!("Wrap width: {:?}", wrap_width);
1275        log::info!("Excerpt Header Height: {:?}", excerpt_header_height);
1276
1277        let buffer = if rng.gen() {
1278            let len = rng.gen_range(0..10);
1279            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1280            log::info!("initial buffer text: {:?}", text);
1281            MultiBuffer::build_simple(&text, cx)
1282        } else {
1283            MultiBuffer::build_random(&mut rng, cx)
1284        };
1285
1286        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1287        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1288        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1289        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1290        let (wrap_map, wraps_snapshot) =
1291            WrapMap::new(tab_snapshot, font_id, font_size, wrap_width, cx);
1292        let mut block_map = BlockMap::new(
1293            wraps_snapshot,
1294            buffer_start_header_height,
1295            excerpt_header_height,
1296        );
1297        let mut custom_blocks = Vec::new();
1298
1299        for _ in 0..operations {
1300            let mut buffer_edits = Vec::new();
1301            match rng.gen_range(0..=100) {
1302                0..=19 => {
1303                    let wrap_width = if rng.gen_bool(0.2) {
1304                        None
1305                    } else {
1306                        Some(rng.gen_range(0.0..=100.0))
1307                    };
1308                    log::info!("Setting wrap width to {:?}", wrap_width);
1309                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1310                }
1311                20..=39 => {
1312                    let block_count = rng.gen_range(1..=5);
1313                    let block_properties = (0..block_count)
1314                        .map(|_| {
1315                            let buffer = buffer.read(cx).read(cx);
1316                            let position = buffer.anchor_after(
1317                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1318                            );
1319
1320                            let disposition = if rng.gen() {
1321                                BlockDisposition::Above
1322                            } else {
1323                                BlockDisposition::Below
1324                            };
1325                            let height = rng.gen_range(1..5);
1326                            log::info!(
1327                                "inserting block {:?} {:?} with height {}",
1328                                disposition,
1329                                position.to_point(&buffer),
1330                                height
1331                            );
1332                            BlockProperties {
1333                                style: BlockStyle::Fixed,
1334                                position,
1335                                height,
1336                                disposition,
1337                                render: Arc::new(|_| Empty::new().into_any()),
1338                            }
1339                        })
1340                        .collect::<Vec<_>>();
1341
1342                    let (inlay_snapshot, inlay_edits) =
1343                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1344                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1345                    let (tab_snapshot, tab_edits) =
1346                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1347                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1348                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1349                    });
1350                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1351                    let block_ids = block_map.insert(block_properties.clone());
1352                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1353                        custom_blocks.push((block_id, props));
1354                    }
1355                }
1356                40..=59 if !custom_blocks.is_empty() => {
1357                    let block_count = rng.gen_range(1..=4.min(custom_blocks.len()));
1358                    let block_ids_to_remove = (0..block_count)
1359                        .map(|_| {
1360                            custom_blocks
1361                                .remove(rng.gen_range(0..custom_blocks.len()))
1362                                .0
1363                        })
1364                        .collect();
1365
1366                    let (inlay_snapshot, inlay_edits) =
1367                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1368                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1369                    let (tab_snapshot, tab_edits) =
1370                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1371                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1372                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1373                    });
1374                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1375                    block_map.remove(block_ids_to_remove);
1376                }
1377                _ => {
1378                    buffer.update(cx, |buffer, cx| {
1379                        let mutation_count = rng.gen_range(1..=5);
1380                        let subscription = buffer.subscribe();
1381                        buffer.randomly_mutate(&mut rng, mutation_count, cx);
1382                        buffer_snapshot = buffer.snapshot(cx);
1383                        buffer_edits.extend(subscription.consume());
1384                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1385                    });
1386                }
1387            }
1388
1389            let (inlay_snapshot, inlay_edits) =
1390                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1391            let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1392            let (tab_snapshot, tab_edits) = tab_map.sync(fold_snapshot, fold_edits, tab_size);
1393            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1394                wrap_map.sync(tab_snapshot, tab_edits, cx)
1395            });
1396            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1397            assert_eq!(
1398                blocks_snapshot.transforms.summary().input_rows,
1399                wraps_snapshot.max_point().row() + 1
1400            );
1401            log::info!("blocks text: {:?}", blocks_snapshot.text());
1402
1403            let mut expected_blocks = Vec::new();
1404            expected_blocks.extend(custom_blocks.iter().map(|(id, block)| {
1405                let mut position = block.position.to_point(&buffer_snapshot);
1406                match block.disposition {
1407                    BlockDisposition::Above => {
1408                        position.column = 0;
1409                    }
1410                    BlockDisposition::Below => {
1411                        position.column = buffer_snapshot.line_len(position.row);
1412                    }
1413                };
1414                let row = wraps_snapshot.make_wrap_point(position, Bias::Left).row();
1415                (
1416                    row,
1417                    ExpectedBlock::Custom {
1418                        disposition: block.disposition,
1419                        id: *id,
1420                        height: block.height,
1421                    },
1422                )
1423            }));
1424            expected_blocks.extend(buffer_snapshot.excerpt_boundaries_in_range(0..).map(
1425                |boundary| {
1426                    let position =
1427                        wraps_snapshot.make_wrap_point(Point::new(boundary.row, 0), Bias::Left);
1428                    (
1429                        position.row(),
1430                        ExpectedBlock::ExcerptHeader {
1431                            height: if boundary.starts_new_buffer {
1432                                buffer_start_header_height
1433                            } else {
1434                                excerpt_header_height
1435                            },
1436                            starts_new_buffer: boundary.starts_new_buffer,
1437                        },
1438                    )
1439                },
1440            ));
1441            expected_blocks.sort_unstable();
1442            let mut sorted_blocks_iter = expected_blocks.into_iter().peekable();
1443
1444            let input_buffer_rows = buffer_snapshot.buffer_rows(0).collect::<Vec<_>>();
1445            let mut expected_buffer_rows = Vec::new();
1446            let mut expected_text = String::new();
1447            let mut expected_block_positions = Vec::new();
1448            let input_text = wraps_snapshot.text();
1449            for (row, input_line) in input_text.split('\n').enumerate() {
1450                let row = row as u32;
1451                if row > 0 {
1452                    expected_text.push('\n');
1453                }
1454
1455                let buffer_row = input_buffer_rows[wraps_snapshot
1456                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1457                    .row as usize];
1458
1459                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1460                    if *block_row == row && block.disposition() == BlockDisposition::Above {
1461                        let (_, block) = sorted_blocks_iter.next().unwrap();
1462                        let height = block.height() as usize;
1463                        expected_block_positions
1464                            .push((expected_text.matches('\n').count() as u32, block));
1465                        let text = "\n".repeat(height);
1466                        expected_text.push_str(&text);
1467                        for _ in 0..height {
1468                            expected_buffer_rows.push(None);
1469                        }
1470                    } else {
1471                        break;
1472                    }
1473                }
1474
1475                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1476                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1477                expected_text.push_str(input_line);
1478
1479                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1480                    if *block_row == row && block.disposition() == BlockDisposition::Below {
1481                        let (_, block) = sorted_blocks_iter.next().unwrap();
1482                        let height = block.height() as usize;
1483                        expected_block_positions
1484                            .push((expected_text.matches('\n').count() as u32 + 1, block));
1485                        let text = "\n".repeat(height);
1486                        expected_text.push_str(&text);
1487                        for _ in 0..height {
1488                            expected_buffer_rows.push(None);
1489                        }
1490                    } else {
1491                        break;
1492                    }
1493                }
1494            }
1495
1496            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1497            let expected_row_count = expected_lines.len();
1498            for start_row in 0..expected_row_count {
1499                let expected_text = expected_lines[start_row..].join("\n");
1500                let actual_text = blocks_snapshot
1501                    .chunks(
1502                        start_row as u32..blocks_snapshot.max_point().row + 1,
1503                        false,
1504                        None,
1505                        None,
1506                        None,
1507                    )
1508                    .map(|chunk| chunk.text)
1509                    .collect::<String>();
1510                assert_eq!(
1511                    actual_text, expected_text,
1512                    "incorrect text starting from row {}",
1513                    start_row
1514                );
1515                assert_eq!(
1516                    blocks_snapshot
1517                        .buffer_rows(start_row as u32)
1518                        .collect::<Vec<_>>(),
1519                    &expected_buffer_rows[start_row..]
1520                );
1521            }
1522
1523            assert_eq!(
1524                blocks_snapshot
1525                    .blocks_in_range(0..(expected_row_count as u32))
1526                    .map(|(row, block)| (row, block.clone().into()))
1527                    .collect::<Vec<_>>(),
1528                expected_block_positions
1529            );
1530
1531            let mut expected_longest_rows = Vec::new();
1532            let mut longest_line_len = -1_isize;
1533            for (row, line) in expected_lines.iter().enumerate() {
1534                let row = row as u32;
1535
1536                assert_eq!(
1537                    blocks_snapshot.line_len(row),
1538                    line.len() as u32,
1539                    "invalid line len for row {}",
1540                    row
1541                );
1542
1543                let line_char_count = line.chars().count() as isize;
1544                match line_char_count.cmp(&longest_line_len) {
1545                    Ordering::Less => {}
1546                    Ordering::Equal => expected_longest_rows.push(row),
1547                    Ordering::Greater => {
1548                        longest_line_len = line_char_count;
1549                        expected_longest_rows.clear();
1550                        expected_longest_rows.push(row);
1551                    }
1552                }
1553            }
1554
1555            let longest_row = blocks_snapshot.longest_row();
1556            assert!(
1557                expected_longest_rows.contains(&longest_row),
1558                "incorrect longest row {}. expected {:?} with length {}",
1559                longest_row,
1560                expected_longest_rows,
1561                longest_line_len,
1562            );
1563
1564            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1565                let wrap_point = WrapPoint::new(row, 0);
1566                let block_point = blocks_snapshot.to_block_point(wrap_point);
1567                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1568            }
1569
1570            let mut block_point = BlockPoint::new(0, 0);
1571            for c in expected_text.chars() {
1572                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1573                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1574                assert_eq!(
1575                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1576                    left_point
1577                );
1578                assert_eq!(
1579                    left_buffer_point,
1580                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1581                    "{:?} is not valid in buffer coordinates",
1582                    left_point
1583                );
1584
1585                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1586                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1587                assert_eq!(
1588                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1589                    right_point
1590                );
1591                assert_eq!(
1592                    right_buffer_point,
1593                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1594                    "{:?} is not valid in buffer coordinates",
1595                    right_point
1596                );
1597
1598                if c == '\n' {
1599                    block_point.0 += Point::new(1, 0);
1600                } else {
1601                    block_point.column += c.len_utf8() as u32;
1602                }
1603            }
1604        }
1605
1606        #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)]
1607        enum ExpectedBlock {
1608            ExcerptHeader {
1609                height: u8,
1610                starts_new_buffer: bool,
1611            },
1612            Custom {
1613                disposition: BlockDisposition,
1614                id: BlockId,
1615                height: u8,
1616            },
1617        }
1618
1619        impl ExpectedBlock {
1620            fn height(&self) -> u8 {
1621                match self {
1622                    ExpectedBlock::ExcerptHeader { height, .. } => *height,
1623                    ExpectedBlock::Custom { height, .. } => *height,
1624                }
1625            }
1626
1627            fn disposition(&self) -> BlockDisposition {
1628                match self {
1629                    ExpectedBlock::ExcerptHeader { .. } => BlockDisposition::Above,
1630                    ExpectedBlock::Custom { disposition, .. } => *disposition,
1631                }
1632            }
1633        }
1634
1635        impl From<TransformBlock> for ExpectedBlock {
1636            fn from(block: TransformBlock) -> Self {
1637                match block {
1638                    TransformBlock::Custom(block) => ExpectedBlock::Custom {
1639                        id: block.id,
1640                        disposition: block.disposition,
1641                        height: block.height,
1642                    },
1643                    TransformBlock::ExcerptHeader {
1644                        height,
1645                        starts_new_buffer,
1646                        ..
1647                    } => ExpectedBlock::ExcerptHeader {
1648                        height,
1649                        starts_new_buffer,
1650                    },
1651                }
1652            }
1653        }
1654    }
1655
1656    fn init_test(cx: &mut gpui::AppContext) {
1657        cx.set_global(SettingsStore::test(cx));
1658        theme::init((), cx);
1659    }
1660
1661    impl TransformBlock {
1662        fn as_custom(&self) -> Option<&Block> {
1663            match self {
1664                TransformBlock::Custom(block) => Some(block),
1665                TransformBlock::ExcerptHeader { .. } => None,
1666            }
1667        }
1668    }
1669
1670    impl BlockSnapshot {
1671        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1672            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1673        }
1674    }
1675}