block_map.rs

   1use super::{
   2    wrap_map::{self, WrapEdit, WrapPoint, WrapSnapshot},
   3    InlayHighlights, 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            None,
 583        )
 584        .map(|chunk| chunk.text)
 585        .collect()
 586    }
 587
 588    pub fn chunks<'a>(
 589        &'a self,
 590        rows: Range<u32>,
 591        language_aware: bool,
 592        text_highlights: Option<&'a TextHighlights>,
 593        inlay_highlights: Option<&'a InlayHighlights>,
 594        inlay_highlight_style: Option<HighlightStyle>,
 595        suggestion_highlight_style: Option<HighlightStyle>,
 596    ) -> BlockChunks<'a> {
 597        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 598        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 599        let input_end = {
 600            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 601            let overshoot = if cursor
 602                .item()
 603                .map_or(false, |transform| transform.is_isomorphic())
 604            {
 605                rows.end - cursor.start().0 .0
 606            } else {
 607                0
 608            };
 609            cursor.start().1 .0 + overshoot
 610        };
 611        let input_start = {
 612            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 613            let overshoot = if cursor
 614                .item()
 615                .map_or(false, |transform| transform.is_isomorphic())
 616            {
 617                rows.start - cursor.start().0 .0
 618            } else {
 619                0
 620            };
 621            cursor.start().1 .0 + overshoot
 622        };
 623        BlockChunks {
 624            input_chunks: self.wrap_snapshot.chunks(
 625                input_start..input_end,
 626                language_aware,
 627                text_highlights,
 628                inlay_highlights,
 629                inlay_highlight_style,
 630                suggestion_highlight_style,
 631            ),
 632            input_chunk: Default::default(),
 633            transforms: cursor,
 634            output_row: rows.start,
 635            max_output_row,
 636        }
 637    }
 638
 639    pub fn buffer_rows(&self, start_row: u32) -> BlockBufferRows {
 640        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 641        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 642        let (output_start, input_start) = cursor.start();
 643        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 644            start_row - output_start.0
 645        } else {
 646            0
 647        };
 648        let input_start_row = input_start.0 + overshoot;
 649        BlockBufferRows {
 650            transforms: cursor,
 651            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 652            output_row: start_row,
 653            started: false,
 654        }
 655    }
 656
 657    pub fn blocks_in_range(
 658        &self,
 659        rows: Range<u32>,
 660    ) -> impl Iterator<Item = (u32, &TransformBlock)> {
 661        let mut cursor = self.transforms.cursor::<BlockRow>();
 662        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 663        std::iter::from_fn(move || {
 664            while let Some(transform) = cursor.item() {
 665                let start_row = cursor.start().0;
 666                if start_row >= rows.end {
 667                    break;
 668                }
 669                if let Some(block) = &transform.block {
 670                    cursor.next(&());
 671                    return Some((start_row, block));
 672                } else {
 673                    cursor.next(&());
 674                }
 675            }
 676            None
 677        })
 678    }
 679
 680    pub fn max_point(&self) -> BlockPoint {
 681        let row = self.transforms.summary().output_rows - 1;
 682        BlockPoint::new(row, self.line_len(row))
 683    }
 684
 685    pub fn longest_row(&self) -> u32 {
 686        let input_row = self.wrap_snapshot.longest_row();
 687        self.to_block_point(WrapPoint::new(input_row, 0)).row
 688    }
 689
 690    pub fn line_len(&self, row: u32) -> u32 {
 691        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 692        cursor.seek(&BlockRow(row), Bias::Right, &());
 693        if let Some(transform) = cursor.item() {
 694            let (output_start, input_start) = cursor.start();
 695            let overshoot = row - output_start.0;
 696            if transform.block.is_some() {
 697                0
 698            } else {
 699                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 700            }
 701        } else {
 702            panic!("row out of range");
 703        }
 704    }
 705
 706    pub fn is_block_line(&self, row: u32) -> bool {
 707        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 708        cursor.seek(&BlockRow(row), Bias::Right, &());
 709        cursor.item().map_or(false, |t| t.block.is_some())
 710    }
 711
 712    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 713        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 714        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 715
 716        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 717        let mut search_left =
 718            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 719        let mut reversed = false;
 720
 721        loop {
 722            if let Some(transform) = cursor.item() {
 723                if transform.is_isomorphic() {
 724                    let (output_start_row, input_start_row) = cursor.start();
 725                    let (output_end_row, input_end_row) = cursor.end(&());
 726                    let output_start = Point::new(output_start_row.0, 0);
 727                    let input_start = Point::new(input_start_row.0, 0);
 728                    let input_end = Point::new(input_end_row.0, 0);
 729                    let input_point = if point.row >= output_end_row.0 {
 730                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 731                        self.wrap_snapshot
 732                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 733                    } else {
 734                        let output_overshoot = point.0.saturating_sub(output_start);
 735                        self.wrap_snapshot
 736                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 737                    };
 738
 739                    if (input_start..input_end).contains(&input_point.0) {
 740                        let input_overshoot = input_point.0.saturating_sub(input_start);
 741                        return BlockPoint(output_start + input_overshoot);
 742                    }
 743                }
 744
 745                if search_left {
 746                    cursor.prev(&());
 747                } else {
 748                    cursor.next(&());
 749                }
 750            } else if reversed {
 751                return self.max_point();
 752            } else {
 753                reversed = true;
 754                search_left = !search_left;
 755                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 756            }
 757        }
 758    }
 759
 760    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 761        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 762        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 763        if let Some(transform) = cursor.item() {
 764            debug_assert!(transform.is_isomorphic());
 765        } else {
 766            return self.max_point();
 767        }
 768
 769        let (input_start_row, output_start_row) = cursor.start();
 770        let input_start = Point::new(input_start_row.0, 0);
 771        let output_start = Point::new(output_start_row.0, 0);
 772        let input_overshoot = wrap_point.0 - input_start;
 773        BlockPoint(output_start + input_overshoot)
 774    }
 775
 776    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 777        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 778        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 779        if let Some(transform) = cursor.item() {
 780            match transform.block.as_ref().map(|b| b.disposition()) {
 781                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 782                Some(BlockDisposition::Below) => {
 783                    let wrap_row = cursor.start().1 .0 - 1;
 784                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 785                }
 786                None => {
 787                    let overshoot = block_point.row - cursor.start().0 .0;
 788                    let wrap_row = cursor.start().1 .0 + overshoot;
 789                    WrapPoint::new(wrap_row, block_point.column)
 790                }
 791            }
 792        } else {
 793            self.wrap_snapshot.max_point()
 794        }
 795    }
 796}
 797
 798impl Transform {
 799    fn isomorphic(rows: u32) -> Self {
 800        Self {
 801            summary: TransformSummary {
 802                input_rows: rows,
 803                output_rows: rows,
 804            },
 805            block: None,
 806        }
 807    }
 808
 809    fn block(block: TransformBlock) -> Self {
 810        Self {
 811            summary: TransformSummary {
 812                input_rows: 0,
 813                output_rows: block.height() as u32,
 814            },
 815            block: Some(block),
 816        }
 817    }
 818
 819    fn is_isomorphic(&self) -> bool {
 820        self.block.is_none()
 821    }
 822}
 823
 824impl<'a> Iterator for BlockChunks<'a> {
 825    type Item = Chunk<'a>;
 826
 827    fn next(&mut self) -> Option<Self::Item> {
 828        if self.output_row >= self.max_output_row {
 829            return None;
 830        }
 831
 832        let transform = self.transforms.item()?;
 833        if transform.block.is_some() {
 834            let block_start = self.transforms.start().0 .0;
 835            let mut block_end = self.transforms.end(&()).0 .0;
 836            self.transforms.next(&());
 837            if self.transforms.item().is_none() {
 838                block_end -= 1;
 839            }
 840
 841            let start_in_block = self.output_row - block_start;
 842            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 843            let line_count = end_in_block - start_in_block;
 844            self.output_row += line_count;
 845
 846            return Some(Chunk {
 847                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 848                ..Default::default()
 849            });
 850        }
 851
 852        if self.input_chunk.text.is_empty() {
 853            if let Some(input_chunk) = self.input_chunks.next() {
 854                self.input_chunk = input_chunk;
 855            } else {
 856                self.output_row += 1;
 857                if self.output_row < self.max_output_row {
 858                    self.transforms.next(&());
 859                    return Some(Chunk {
 860                        text: "\n",
 861                        ..Default::default()
 862                    });
 863                } else {
 864                    return None;
 865                }
 866            }
 867        }
 868
 869        let transform_end = self.transforms.end(&()).0 .0;
 870        let (prefix_rows, prefix_bytes) =
 871            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 872        self.output_row += prefix_rows;
 873        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 874        self.input_chunk.text = suffix;
 875        if self.output_row == transform_end {
 876            self.transforms.next(&());
 877        }
 878
 879        Some(Chunk {
 880            text: prefix,
 881            ..self.input_chunk
 882        })
 883    }
 884}
 885
 886impl<'a> Iterator for BlockBufferRows<'a> {
 887    type Item = Option<u32>;
 888
 889    fn next(&mut self) -> Option<Self::Item> {
 890        if self.started {
 891            self.output_row += 1;
 892        } else {
 893            self.started = true;
 894        }
 895
 896        if self.output_row >= self.transforms.end(&()).0 .0 {
 897            self.transforms.next(&());
 898        }
 899
 900        let transform = self.transforms.item()?;
 901        if transform.block.is_some() {
 902            Some(None)
 903        } else {
 904            Some(self.input_buffer_rows.next().unwrap())
 905        }
 906    }
 907}
 908
 909impl sum_tree::Item for Transform {
 910    type Summary = TransformSummary;
 911
 912    fn summary(&self) -> Self::Summary {
 913        self.summary.clone()
 914    }
 915}
 916
 917impl sum_tree::Summary for TransformSummary {
 918    type Context = ();
 919
 920    fn add_summary(&mut self, summary: &Self, _: &()) {
 921        self.input_rows += summary.input_rows;
 922        self.output_rows += summary.output_rows;
 923    }
 924}
 925
 926impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 927    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 928        self.0 += summary.input_rows;
 929    }
 930}
 931
 932impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 933    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 934        self.0 += summary.output_rows;
 935    }
 936}
 937
 938impl BlockDisposition {
 939    fn is_below(&self) -> bool {
 940        matches!(self, BlockDisposition::Below)
 941    }
 942}
 943
 944impl<'a, 'b, 'c> Deref for BlockContext<'a, 'b, 'c> {
 945    type Target = ViewContext<'a, 'b, Editor>;
 946
 947    fn deref(&self) -> &Self::Target {
 948        self.view_context
 949    }
 950}
 951
 952impl DerefMut for BlockContext<'_, '_, '_> {
 953    fn deref_mut(&mut self) -> &mut Self::Target {
 954        self.view_context
 955    }
 956}
 957
 958impl Block {
 959    pub fn render(&self, cx: &mut BlockContext) -> AnyElement<Editor> {
 960        self.render.lock()(cx)
 961    }
 962
 963    pub fn position(&self) -> &Anchor {
 964        &self.position
 965    }
 966
 967    pub fn style(&self) -> BlockStyle {
 968        self.style
 969    }
 970}
 971
 972impl Debug for Block {
 973    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 974        f.debug_struct("Block")
 975            .field("id", &self.id)
 976            .field("position", &self.position)
 977            .field("disposition", &self.disposition)
 978            .finish()
 979    }
 980}
 981
 982// Count the number of bytes prior to a target point. If the string doesn't contain the target
 983// point, return its total extent. Otherwise return the target point itself.
 984fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 985    let mut row = 0;
 986    let mut offset = 0;
 987    for (ix, line) in s.split('\n').enumerate() {
 988        if ix > 0 {
 989            row += 1;
 990            offset += 1;
 991        }
 992        if row >= target {
 993            break;
 994        }
 995        offset += line.len() as usize;
 996    }
 997    (row, offset)
 998}
 999
1000#[cfg(test)]
1001mod tests {
1002    use super::*;
1003    use crate::display_map::inlay_map::InlayMap;
1004    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
1005    use crate::multi_buffer::MultiBuffer;
1006    use gpui::{elements::Empty, Element};
1007    use rand::prelude::*;
1008    use settings::SettingsStore;
1009    use std::env;
1010    use util::RandomCharIter;
1011
1012    #[gpui::test]
1013    fn test_offset_for_row() {
1014        assert_eq!(offset_for_row("", 0), (0, 0));
1015        assert_eq!(offset_for_row("", 1), (0, 0));
1016        assert_eq!(offset_for_row("abcd", 0), (0, 0));
1017        assert_eq!(offset_for_row("abcd", 1), (0, 4));
1018        assert_eq!(offset_for_row("\n", 0), (0, 0));
1019        assert_eq!(offset_for_row("\n", 1), (1, 1));
1020        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
1021        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
1022        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
1023        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
1024    }
1025
1026    #[gpui::test]
1027    fn test_basic_blocks(cx: &mut gpui::AppContext) {
1028        init_test(cx);
1029
1030        let family_id = cx
1031            .font_cache()
1032            .load_family(&["Helvetica"], &Default::default())
1033            .unwrap();
1034        let font_id = cx
1035            .font_cache()
1036            .select_font(family_id, &Default::default())
1037            .unwrap();
1038
1039        let text = "aaa\nbbb\nccc\nddd";
1040
1041        let buffer = MultiBuffer::build_simple(text, cx);
1042        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1043        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1044        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1045        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1046        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 1.try_into().unwrap());
1047        let (wrap_map, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, None, cx);
1048        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1049
1050        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1051        let block_ids = writer.insert(vec![
1052            BlockProperties {
1053                style: BlockStyle::Fixed,
1054                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
1055                height: 1,
1056                disposition: BlockDisposition::Above,
1057                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1058            },
1059            BlockProperties {
1060                style: BlockStyle::Fixed,
1061                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
1062                height: 2,
1063                disposition: BlockDisposition::Above,
1064                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1065            },
1066            BlockProperties {
1067                style: BlockStyle::Fixed,
1068                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
1069                height: 3,
1070                disposition: BlockDisposition::Below,
1071                render: Arc::new(|_| Empty::new().into_any_named("block 3")),
1072            },
1073        ]);
1074
1075        let snapshot = block_map.read(wraps_snapshot, Default::default());
1076        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1077
1078        let blocks = snapshot
1079            .blocks_in_range(0..8)
1080            .map(|(start_row, block)| {
1081                let block = block.as_custom().unwrap();
1082                (start_row..start_row + block.height as u32, block.id)
1083            })
1084            .collect::<Vec<_>>();
1085
1086        // When multiple blocks are on the same line, the newer blocks appear first.
1087        assert_eq!(
1088            blocks,
1089            &[
1090                (1..2, block_ids[0]),
1091                (2..4, block_ids[1]),
1092                (7..10, block_ids[2]),
1093            ]
1094        );
1095
1096        assert_eq!(
1097            snapshot.to_block_point(WrapPoint::new(0, 3)),
1098            BlockPoint::new(0, 3)
1099        );
1100        assert_eq!(
1101            snapshot.to_block_point(WrapPoint::new(1, 0)),
1102            BlockPoint::new(4, 0)
1103        );
1104        assert_eq!(
1105            snapshot.to_block_point(WrapPoint::new(3, 3)),
1106            BlockPoint::new(6, 3)
1107        );
1108
1109        assert_eq!(
1110            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
1111            WrapPoint::new(0, 3)
1112        );
1113        assert_eq!(
1114            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
1115            WrapPoint::new(1, 0)
1116        );
1117        assert_eq!(
1118            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
1119            WrapPoint::new(1, 0)
1120        );
1121        assert_eq!(
1122            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
1123            WrapPoint::new(3, 3)
1124        );
1125
1126        assert_eq!(
1127            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
1128            BlockPoint::new(0, 3)
1129        );
1130        assert_eq!(
1131            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1132            BlockPoint::new(4, 0)
1133        );
1134        assert_eq!(
1135            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1136            BlockPoint::new(0, 3)
1137        );
1138        assert_eq!(
1139            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1140            BlockPoint::new(4, 0)
1141        );
1142        assert_eq!(
1143            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1144            BlockPoint::new(4, 0)
1145        );
1146        assert_eq!(
1147            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1148            BlockPoint::new(4, 0)
1149        );
1150        assert_eq!(
1151            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1152            BlockPoint::new(6, 3)
1153        );
1154        assert_eq!(
1155            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1156            BlockPoint::new(6, 3)
1157        );
1158        assert_eq!(
1159            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1160            BlockPoint::new(6, 3)
1161        );
1162        assert_eq!(
1163            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1164            BlockPoint::new(6, 3)
1165        );
1166
1167        assert_eq!(
1168            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1169            &[
1170                Some(0),
1171                None,
1172                None,
1173                None,
1174                Some(1),
1175                Some(2),
1176                Some(3),
1177                None,
1178                None,
1179                None
1180            ]
1181        );
1182
1183        // Insert a line break, separating two block decorations into separate lines.
1184        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1185            buffer.edit([(Point::new(1, 1)..Point::new(1, 1), "!!!\n")], None, cx);
1186            buffer.snapshot(cx)
1187        });
1188
1189        let (inlay_snapshot, inlay_edits) =
1190            inlay_map.sync(buffer_snapshot, subscription.consume().into_inner());
1191        let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1192        let (tab_snapshot, tab_edits) =
1193            tab_map.sync(fold_snapshot, fold_edits, 4.try_into().unwrap());
1194        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1195            wrap_map.sync(tab_snapshot, tab_edits, cx)
1196        });
1197        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1198        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1199    }
1200
1201    #[gpui::test]
1202    fn test_blocks_on_wrapped_lines(cx: &mut gpui::AppContext) {
1203        init_test(cx);
1204
1205        let family_id = cx
1206            .font_cache()
1207            .load_family(&["Helvetica"], &Default::default())
1208            .unwrap();
1209        let font_id = cx
1210            .font_cache()
1211            .select_font(family_id, &Default::default())
1212            .unwrap();
1213
1214        let text = "one two three\nfour five six\nseven eight";
1215
1216        let buffer = MultiBuffer::build_simple(text, cx);
1217        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1218        let (_, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1219        let (_, fold_snapshot) = FoldMap::new(inlay_snapshot);
1220        let (_, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1221        let (_, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, Some(60.), cx);
1222        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1223
1224        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1225        writer.insert(vec![
1226            BlockProperties {
1227                style: BlockStyle::Fixed,
1228                position: buffer_snapshot.anchor_after(Point::new(1, 12)),
1229                disposition: BlockDisposition::Above,
1230                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1231                height: 1,
1232            },
1233            BlockProperties {
1234                style: BlockStyle::Fixed,
1235                position: buffer_snapshot.anchor_after(Point::new(1, 1)),
1236                disposition: BlockDisposition::Below,
1237                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1238                height: 1,
1239            },
1240        ]);
1241
1242        // Blocks with an 'above' disposition go above their corresponding buffer line.
1243        // Blocks with a 'below' disposition go below their corresponding buffer line.
1244        let snapshot = block_map.read(wraps_snapshot, Default::default());
1245        assert_eq!(
1246            snapshot.text(),
1247            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1248        );
1249    }
1250
1251    #[gpui::test(iterations = 100)]
1252    fn test_random_blocks(cx: &mut gpui::AppContext, mut rng: StdRng) {
1253        init_test(cx);
1254
1255        let operations = env::var("OPERATIONS")
1256            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1257            .unwrap_or(10);
1258
1259        let wrap_width = if rng.gen_bool(0.2) {
1260            None
1261        } else {
1262            Some(rng.gen_range(0.0..=100.0))
1263        };
1264        let tab_size = 1.try_into().unwrap();
1265        let family_id = cx
1266            .font_cache()
1267            .load_family(&["Helvetica"], &Default::default())
1268            .unwrap();
1269        let font_id = cx
1270            .font_cache()
1271            .select_font(family_id, &Default::default())
1272            .unwrap();
1273        let font_size = 14.0;
1274        let buffer_start_header_height = rng.gen_range(1..=5);
1275        let excerpt_header_height = rng.gen_range(1..=5);
1276
1277        log::info!("Wrap width: {:?}", wrap_width);
1278        log::info!("Excerpt Header Height: {:?}", excerpt_header_height);
1279
1280        let buffer = if rng.gen() {
1281            let len = rng.gen_range(0..10);
1282            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1283            log::info!("initial buffer text: {:?}", text);
1284            MultiBuffer::build_simple(&text, cx)
1285        } else {
1286            MultiBuffer::build_random(&mut rng, cx)
1287        };
1288
1289        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1290        let (mut inlay_map, inlay_snapshot) = InlayMap::new(buffer_snapshot.clone());
1291        let (mut fold_map, fold_snapshot) = FoldMap::new(inlay_snapshot);
1292        let (mut tab_map, tab_snapshot) = TabMap::new(fold_snapshot, 4.try_into().unwrap());
1293        let (wrap_map, wraps_snapshot) =
1294            WrapMap::new(tab_snapshot, font_id, font_size, wrap_width, cx);
1295        let mut block_map = BlockMap::new(
1296            wraps_snapshot,
1297            buffer_start_header_height,
1298            excerpt_header_height,
1299        );
1300        let mut custom_blocks = Vec::new();
1301
1302        for _ in 0..operations {
1303            let mut buffer_edits = Vec::new();
1304            match rng.gen_range(0..=100) {
1305                0..=19 => {
1306                    let wrap_width = if rng.gen_bool(0.2) {
1307                        None
1308                    } else {
1309                        Some(rng.gen_range(0.0..=100.0))
1310                    };
1311                    log::info!("Setting wrap width to {:?}", wrap_width);
1312                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1313                }
1314                20..=39 => {
1315                    let block_count = rng.gen_range(1..=5);
1316                    let block_properties = (0..block_count)
1317                        .map(|_| {
1318                            let buffer = buffer.read(cx).read(cx);
1319                            let position = buffer.anchor_after(
1320                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1321                            );
1322
1323                            let disposition = if rng.gen() {
1324                                BlockDisposition::Above
1325                            } else {
1326                                BlockDisposition::Below
1327                            };
1328                            let height = rng.gen_range(1..5);
1329                            log::info!(
1330                                "inserting block {:?} {:?} with height {}",
1331                                disposition,
1332                                position.to_point(&buffer),
1333                                height
1334                            );
1335                            BlockProperties {
1336                                style: BlockStyle::Fixed,
1337                                position,
1338                                height,
1339                                disposition,
1340                                render: Arc::new(|_| Empty::new().into_any()),
1341                            }
1342                        })
1343                        .collect::<Vec<_>>();
1344
1345                    let (inlay_snapshot, inlay_edits) =
1346                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1347                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1348                    let (tab_snapshot, tab_edits) =
1349                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1350                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1351                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1352                    });
1353                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1354                    let block_ids = block_map.insert(block_properties.clone());
1355                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1356                        custom_blocks.push((block_id, props));
1357                    }
1358                }
1359                40..=59 if !custom_blocks.is_empty() => {
1360                    let block_count = rng.gen_range(1..=4.min(custom_blocks.len()));
1361                    let block_ids_to_remove = (0..block_count)
1362                        .map(|_| {
1363                            custom_blocks
1364                                .remove(rng.gen_range(0..custom_blocks.len()))
1365                                .0
1366                        })
1367                        .collect();
1368
1369                    let (inlay_snapshot, inlay_edits) =
1370                        inlay_map.sync(buffer_snapshot.clone(), vec![]);
1371                    let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1372                    let (tab_snapshot, tab_edits) =
1373                        tab_map.sync(fold_snapshot, fold_edits, tab_size);
1374                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1375                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1376                    });
1377                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1378                    block_map.remove(block_ids_to_remove);
1379                }
1380                _ => {
1381                    buffer.update(cx, |buffer, cx| {
1382                        let mutation_count = rng.gen_range(1..=5);
1383                        let subscription = buffer.subscribe();
1384                        buffer.randomly_mutate(&mut rng, mutation_count, cx);
1385                        buffer_snapshot = buffer.snapshot(cx);
1386                        buffer_edits.extend(subscription.consume());
1387                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1388                    });
1389                }
1390            }
1391
1392            let (inlay_snapshot, inlay_edits) =
1393                inlay_map.sync(buffer_snapshot.clone(), buffer_edits);
1394            let (fold_snapshot, fold_edits) = fold_map.read(inlay_snapshot, inlay_edits);
1395            let (tab_snapshot, tab_edits) = tab_map.sync(fold_snapshot, fold_edits, tab_size);
1396            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1397                wrap_map.sync(tab_snapshot, tab_edits, cx)
1398            });
1399            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1400            assert_eq!(
1401                blocks_snapshot.transforms.summary().input_rows,
1402                wraps_snapshot.max_point().row() + 1
1403            );
1404            log::info!("blocks text: {:?}", blocks_snapshot.text());
1405
1406            let mut expected_blocks = Vec::new();
1407            expected_blocks.extend(custom_blocks.iter().map(|(id, block)| {
1408                let mut position = block.position.to_point(&buffer_snapshot);
1409                match block.disposition {
1410                    BlockDisposition::Above => {
1411                        position.column = 0;
1412                    }
1413                    BlockDisposition::Below => {
1414                        position.column = buffer_snapshot.line_len(position.row);
1415                    }
1416                };
1417                let row = wraps_snapshot.make_wrap_point(position, Bias::Left).row();
1418                (
1419                    row,
1420                    ExpectedBlock::Custom {
1421                        disposition: block.disposition,
1422                        id: *id,
1423                        height: block.height,
1424                    },
1425                )
1426            }));
1427            expected_blocks.extend(buffer_snapshot.excerpt_boundaries_in_range(0..).map(
1428                |boundary| {
1429                    let position =
1430                        wraps_snapshot.make_wrap_point(Point::new(boundary.row, 0), Bias::Left);
1431                    (
1432                        position.row(),
1433                        ExpectedBlock::ExcerptHeader {
1434                            height: if boundary.starts_new_buffer {
1435                                buffer_start_header_height
1436                            } else {
1437                                excerpt_header_height
1438                            },
1439                            starts_new_buffer: boundary.starts_new_buffer,
1440                        },
1441                    )
1442                },
1443            ));
1444            expected_blocks.sort_unstable();
1445            let mut sorted_blocks_iter = expected_blocks.into_iter().peekable();
1446
1447            let input_buffer_rows = buffer_snapshot.buffer_rows(0).collect::<Vec<_>>();
1448            let mut expected_buffer_rows = Vec::new();
1449            let mut expected_text = String::new();
1450            let mut expected_block_positions = Vec::new();
1451            let input_text = wraps_snapshot.text();
1452            for (row, input_line) in input_text.split('\n').enumerate() {
1453                let row = row as u32;
1454                if row > 0 {
1455                    expected_text.push('\n');
1456                }
1457
1458                let buffer_row = input_buffer_rows[wraps_snapshot
1459                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1460                    .row as usize];
1461
1462                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1463                    if *block_row == row && block.disposition() == BlockDisposition::Above {
1464                        let (_, block) = sorted_blocks_iter.next().unwrap();
1465                        let height = block.height() as usize;
1466                        expected_block_positions
1467                            .push((expected_text.matches('\n').count() as u32, block));
1468                        let text = "\n".repeat(height);
1469                        expected_text.push_str(&text);
1470                        for _ in 0..height {
1471                            expected_buffer_rows.push(None);
1472                        }
1473                    } else {
1474                        break;
1475                    }
1476                }
1477
1478                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1479                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1480                expected_text.push_str(input_line);
1481
1482                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1483                    if *block_row == row && block.disposition() == BlockDisposition::Below {
1484                        let (_, block) = sorted_blocks_iter.next().unwrap();
1485                        let height = block.height() as usize;
1486                        expected_block_positions
1487                            .push((expected_text.matches('\n').count() as u32 + 1, block));
1488                        let text = "\n".repeat(height);
1489                        expected_text.push_str(&text);
1490                        for _ in 0..height {
1491                            expected_buffer_rows.push(None);
1492                        }
1493                    } else {
1494                        break;
1495                    }
1496                }
1497            }
1498
1499            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1500            let expected_row_count = expected_lines.len();
1501            for start_row in 0..expected_row_count {
1502                let expected_text = expected_lines[start_row..].join("\n");
1503                let actual_text = blocks_snapshot
1504                    .chunks(
1505                        start_row as u32..blocks_snapshot.max_point().row + 1,
1506                        false,
1507                        None,
1508                        None,
1509                        None,
1510                        None,
1511                    )
1512                    .map(|chunk| chunk.text)
1513                    .collect::<String>();
1514                assert_eq!(
1515                    actual_text, expected_text,
1516                    "incorrect text starting from row {}",
1517                    start_row
1518                );
1519                assert_eq!(
1520                    blocks_snapshot
1521                        .buffer_rows(start_row as u32)
1522                        .collect::<Vec<_>>(),
1523                    &expected_buffer_rows[start_row..]
1524                );
1525            }
1526
1527            assert_eq!(
1528                blocks_snapshot
1529                    .blocks_in_range(0..(expected_row_count as u32))
1530                    .map(|(row, block)| (row, block.clone().into()))
1531                    .collect::<Vec<_>>(),
1532                expected_block_positions
1533            );
1534
1535            let mut expected_longest_rows = Vec::new();
1536            let mut longest_line_len = -1_isize;
1537            for (row, line) in expected_lines.iter().enumerate() {
1538                let row = row as u32;
1539
1540                assert_eq!(
1541                    blocks_snapshot.line_len(row),
1542                    line.len() as u32,
1543                    "invalid line len for row {}",
1544                    row
1545                );
1546
1547                let line_char_count = line.chars().count() as isize;
1548                match line_char_count.cmp(&longest_line_len) {
1549                    Ordering::Less => {}
1550                    Ordering::Equal => expected_longest_rows.push(row),
1551                    Ordering::Greater => {
1552                        longest_line_len = line_char_count;
1553                        expected_longest_rows.clear();
1554                        expected_longest_rows.push(row);
1555                    }
1556                }
1557            }
1558
1559            let longest_row = blocks_snapshot.longest_row();
1560            assert!(
1561                expected_longest_rows.contains(&longest_row),
1562                "incorrect longest row {}. expected {:?} with length {}",
1563                longest_row,
1564                expected_longest_rows,
1565                longest_line_len,
1566            );
1567
1568            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1569                let wrap_point = WrapPoint::new(row, 0);
1570                let block_point = blocks_snapshot.to_block_point(wrap_point);
1571                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1572            }
1573
1574            let mut block_point = BlockPoint::new(0, 0);
1575            for c in expected_text.chars() {
1576                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1577                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1578                assert_eq!(
1579                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1580                    left_point
1581                );
1582                assert_eq!(
1583                    left_buffer_point,
1584                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1585                    "{:?} is not valid in buffer coordinates",
1586                    left_point
1587                );
1588
1589                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1590                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1591                assert_eq!(
1592                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1593                    right_point
1594                );
1595                assert_eq!(
1596                    right_buffer_point,
1597                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1598                    "{:?} is not valid in buffer coordinates",
1599                    right_point
1600                );
1601
1602                if c == '\n' {
1603                    block_point.0 += Point::new(1, 0);
1604                } else {
1605                    block_point.column += c.len_utf8() as u32;
1606                }
1607            }
1608        }
1609
1610        #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)]
1611        enum ExpectedBlock {
1612            ExcerptHeader {
1613                height: u8,
1614                starts_new_buffer: bool,
1615            },
1616            Custom {
1617                disposition: BlockDisposition,
1618                id: BlockId,
1619                height: u8,
1620            },
1621        }
1622
1623        impl ExpectedBlock {
1624            fn height(&self) -> u8 {
1625                match self {
1626                    ExpectedBlock::ExcerptHeader { height, .. } => *height,
1627                    ExpectedBlock::Custom { height, .. } => *height,
1628                }
1629            }
1630
1631            fn disposition(&self) -> BlockDisposition {
1632                match self {
1633                    ExpectedBlock::ExcerptHeader { .. } => BlockDisposition::Above,
1634                    ExpectedBlock::Custom { disposition, .. } => *disposition,
1635                }
1636            }
1637        }
1638
1639        impl From<TransformBlock> for ExpectedBlock {
1640            fn from(block: TransformBlock) -> Self {
1641                match block {
1642                    TransformBlock::Custom(block) => ExpectedBlock::Custom {
1643                        id: block.id,
1644                        disposition: block.disposition,
1645                        height: block.height,
1646                    },
1647                    TransformBlock::ExcerptHeader {
1648                        height,
1649                        starts_new_buffer,
1650                        ..
1651                    } => ExpectedBlock::ExcerptHeader {
1652                        height,
1653                        starts_new_buffer,
1654                    },
1655                }
1656            }
1657        }
1658    }
1659
1660    fn init_test(cx: &mut gpui::AppContext) {
1661        cx.set_global(SettingsStore::test(cx));
1662        theme::init((), cx);
1663    }
1664
1665    impl TransformBlock {
1666        fn as_custom(&self) -> Option<&Block> {
1667            match self {
1668                TransformBlock::Custom(block) => Some(block),
1669                TransformBlock::ExcerptHeader { .. } => None,
1670            }
1671        }
1672    }
1673
1674    impl BlockSnapshot {
1675        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1676            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1677        }
1678    }
1679}