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(0..self.transforms.summary().output_rows, false, None, None)
 577            .map(|chunk| chunk.text)
 578            .collect()
 579    }
 580
 581    pub fn chunks<'a>(
 582        &'a self,
 583        rows: Range<u32>,
 584        language_aware: bool,
 585        text_highlights: Option<&'a TextHighlights>,
 586        suggestion_highlight: Option<HighlightStyle>,
 587    ) -> BlockChunks<'a> {
 588        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 589        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 590        let input_end = {
 591            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 592            let overshoot = if cursor
 593                .item()
 594                .map_or(false, |transform| transform.is_isomorphic())
 595            {
 596                rows.end - cursor.start().0 .0
 597            } else {
 598                0
 599            };
 600            cursor.start().1 .0 + overshoot
 601        };
 602        let input_start = {
 603            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 604            let overshoot = if cursor
 605                .item()
 606                .map_or(false, |transform| transform.is_isomorphic())
 607            {
 608                rows.start - cursor.start().0 .0
 609            } else {
 610                0
 611            };
 612            cursor.start().1 .0 + overshoot
 613        };
 614        BlockChunks {
 615            input_chunks: self.wrap_snapshot.chunks(
 616                input_start..input_end,
 617                language_aware,
 618                text_highlights,
 619                suggestion_highlight,
 620            ),
 621            input_chunk: Default::default(),
 622            transforms: cursor,
 623            output_row: rows.start,
 624            max_output_row,
 625        }
 626    }
 627
 628    pub fn buffer_rows(&self, start_row: u32) -> BlockBufferRows {
 629        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 630        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 631        let (output_start, input_start) = cursor.start();
 632        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 633            start_row - output_start.0
 634        } else {
 635            0
 636        };
 637        let input_start_row = input_start.0 + overshoot;
 638        BlockBufferRows {
 639            transforms: cursor,
 640            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 641            output_row: start_row,
 642            started: false,
 643        }
 644    }
 645
 646    pub fn blocks_in_range(
 647        &self,
 648        rows: Range<u32>,
 649    ) -> impl Iterator<Item = (u32, &TransformBlock)> {
 650        let mut cursor = self.transforms.cursor::<BlockRow>();
 651        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 652        std::iter::from_fn(move || {
 653            while let Some(transform) = cursor.item() {
 654                let start_row = cursor.start().0;
 655                if start_row >= rows.end {
 656                    break;
 657                }
 658                if let Some(block) = &transform.block {
 659                    cursor.next(&());
 660                    return Some((start_row, block));
 661                } else {
 662                    cursor.next(&());
 663                }
 664            }
 665            None
 666        })
 667    }
 668
 669    pub fn max_point(&self) -> BlockPoint {
 670        let row = self.transforms.summary().output_rows - 1;
 671        BlockPoint::new(row, self.line_len(row))
 672    }
 673
 674    pub fn longest_row(&self) -> u32 {
 675        let input_row = self.wrap_snapshot.longest_row();
 676        self.to_block_point(WrapPoint::new(input_row, 0)).row
 677    }
 678
 679    pub fn line_len(&self, row: u32) -> u32 {
 680        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 681        cursor.seek(&BlockRow(row), Bias::Right, &());
 682        if let Some(transform) = cursor.item() {
 683            let (output_start, input_start) = cursor.start();
 684            let overshoot = row - output_start.0;
 685            if transform.block.is_some() {
 686                0
 687            } else {
 688                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 689            }
 690        } else {
 691            panic!("row out of range");
 692        }
 693    }
 694
 695    pub fn is_block_line(&self, row: u32) -> bool {
 696        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 697        cursor.seek(&BlockRow(row), Bias::Right, &());
 698        cursor.item().map_or(false, |t| t.block.is_some())
 699    }
 700
 701    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 702        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 703        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 704
 705        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 706        let mut search_left =
 707            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 708        let mut reversed = false;
 709
 710        loop {
 711            if let Some(transform) = cursor.item() {
 712                if transform.is_isomorphic() {
 713                    let (output_start_row, input_start_row) = cursor.start();
 714                    let (output_end_row, input_end_row) = cursor.end(&());
 715                    let output_start = Point::new(output_start_row.0, 0);
 716                    let input_start = Point::new(input_start_row.0, 0);
 717                    let input_end = Point::new(input_end_row.0, 0);
 718                    let input_point = if point.row >= output_end_row.0 {
 719                        let line_len = self.wrap_snapshot.line_len(input_end_row.0 - 1);
 720                        self.wrap_snapshot
 721                            .clip_point(WrapPoint::new(input_end_row.0 - 1, line_len), bias)
 722                    } else {
 723                        let output_overshoot = point.0.saturating_sub(output_start);
 724                        self.wrap_snapshot
 725                            .clip_point(WrapPoint(input_start + output_overshoot), bias)
 726                    };
 727
 728                    if (input_start..input_end).contains(&input_point.0) {
 729                        let input_overshoot = input_point.0.saturating_sub(input_start);
 730                        return BlockPoint(output_start + input_overshoot);
 731                    }
 732                }
 733
 734                if search_left {
 735                    cursor.prev(&());
 736                } else {
 737                    cursor.next(&());
 738                }
 739            } else if reversed {
 740                return self.max_point();
 741            } else {
 742                reversed = true;
 743                search_left = !search_left;
 744                cursor.seek(&BlockRow(point.row), Bias::Right, &());
 745            }
 746        }
 747    }
 748
 749    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 750        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 751        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 752        if let Some(transform) = cursor.item() {
 753            debug_assert!(transform.is_isomorphic());
 754        } else {
 755            return self.max_point();
 756        }
 757
 758        let (input_start_row, output_start_row) = cursor.start();
 759        let input_start = Point::new(input_start_row.0, 0);
 760        let output_start = Point::new(output_start_row.0, 0);
 761        let input_overshoot = wrap_point.0 - input_start;
 762        BlockPoint(output_start + input_overshoot)
 763    }
 764
 765    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 766        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 767        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 768        if let Some(transform) = cursor.item() {
 769            match transform.block.as_ref().map(|b| b.disposition()) {
 770                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 771                Some(BlockDisposition::Below) => {
 772                    let wrap_row = cursor.start().1 .0 - 1;
 773                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 774                }
 775                None => {
 776                    let overshoot = block_point.row - cursor.start().0 .0;
 777                    let wrap_row = cursor.start().1 .0 + overshoot;
 778                    WrapPoint::new(wrap_row, block_point.column)
 779                }
 780            }
 781        } else {
 782            self.wrap_snapshot.max_point()
 783        }
 784    }
 785}
 786
 787impl Transform {
 788    fn isomorphic(rows: u32) -> Self {
 789        Self {
 790            summary: TransformSummary {
 791                input_rows: rows,
 792                output_rows: rows,
 793            },
 794            block: None,
 795        }
 796    }
 797
 798    fn block(block: TransformBlock) -> Self {
 799        Self {
 800            summary: TransformSummary {
 801                input_rows: 0,
 802                output_rows: block.height() as u32,
 803            },
 804            block: Some(block),
 805        }
 806    }
 807
 808    fn is_isomorphic(&self) -> bool {
 809        self.block.is_none()
 810    }
 811}
 812
 813impl<'a> Iterator for BlockChunks<'a> {
 814    type Item = Chunk<'a>;
 815
 816    fn next(&mut self) -> Option<Self::Item> {
 817        if self.output_row >= self.max_output_row {
 818            return None;
 819        }
 820
 821        let transform = self.transforms.item()?;
 822        if transform.block.is_some() {
 823            let block_start = self.transforms.start().0 .0;
 824            let mut block_end = self.transforms.end(&()).0 .0;
 825            self.transforms.next(&());
 826            if self.transforms.item().is_none() {
 827                block_end -= 1;
 828            }
 829
 830            let start_in_block = self.output_row - block_start;
 831            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 832            let line_count = end_in_block - start_in_block;
 833            self.output_row += line_count;
 834
 835            return Some(Chunk {
 836                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 837                ..Default::default()
 838            });
 839        }
 840
 841        if self.input_chunk.text.is_empty() {
 842            if let Some(input_chunk) = self.input_chunks.next() {
 843                self.input_chunk = input_chunk;
 844            } else {
 845                self.output_row += 1;
 846                if self.output_row < self.max_output_row {
 847                    self.transforms.next(&());
 848                    return Some(Chunk {
 849                        text: "\n",
 850                        ..Default::default()
 851                    });
 852                } else {
 853                    return None;
 854                }
 855            }
 856        }
 857
 858        let transform_end = self.transforms.end(&()).0 .0;
 859        let (prefix_rows, prefix_bytes) =
 860            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 861        self.output_row += prefix_rows;
 862        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 863        self.input_chunk.text = suffix;
 864        if self.output_row == transform_end {
 865            self.transforms.next(&());
 866        }
 867
 868        Some(Chunk {
 869            text: prefix,
 870            ..self.input_chunk
 871        })
 872    }
 873}
 874
 875impl<'a> Iterator for BlockBufferRows<'a> {
 876    type Item = Option<u32>;
 877
 878    fn next(&mut self) -> Option<Self::Item> {
 879        if self.started {
 880            self.output_row += 1;
 881        } else {
 882            self.started = true;
 883        }
 884
 885        if self.output_row >= self.transforms.end(&()).0 .0 {
 886            self.transforms.next(&());
 887        }
 888
 889        let transform = self.transforms.item()?;
 890        if transform.block.is_some() {
 891            Some(None)
 892        } else {
 893            Some(self.input_buffer_rows.next().unwrap())
 894        }
 895    }
 896}
 897
 898impl sum_tree::Item for Transform {
 899    type Summary = TransformSummary;
 900
 901    fn summary(&self) -> Self::Summary {
 902        self.summary.clone()
 903    }
 904}
 905
 906impl sum_tree::Summary for TransformSummary {
 907    type Context = ();
 908
 909    fn add_summary(&mut self, summary: &Self, _: &()) {
 910        self.input_rows += summary.input_rows;
 911        self.output_rows += summary.output_rows;
 912    }
 913}
 914
 915impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 916    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 917        self.0 += summary.input_rows;
 918    }
 919}
 920
 921impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 922    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 923        self.0 += summary.output_rows;
 924    }
 925}
 926
 927impl BlockDisposition {
 928    fn is_below(&self) -> bool {
 929        matches!(self, BlockDisposition::Below)
 930    }
 931}
 932
 933impl<'a, 'b, 'c> Deref for BlockContext<'a, 'b, 'c> {
 934    type Target = ViewContext<'a, 'b, Editor>;
 935
 936    fn deref(&self) -> &Self::Target {
 937        self.view_context
 938    }
 939}
 940
 941impl DerefMut for BlockContext<'_, '_, '_> {
 942    fn deref_mut(&mut self) -> &mut Self::Target {
 943        self.view_context
 944    }
 945}
 946
 947impl Block {
 948    pub fn render(&self, cx: &mut BlockContext) -> AnyElement<Editor> {
 949        self.render.lock()(cx)
 950    }
 951
 952    pub fn position(&self) -> &Anchor {
 953        &self.position
 954    }
 955
 956    pub fn style(&self) -> BlockStyle {
 957        self.style
 958    }
 959}
 960
 961impl Debug for Block {
 962    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 963        f.debug_struct("Block")
 964            .field("id", &self.id)
 965            .field("position", &self.position)
 966            .field("disposition", &self.disposition)
 967            .finish()
 968    }
 969}
 970
 971// Count the number of bytes prior to a target point. If the string doesn't contain the target
 972// point, return its total extent. Otherwise return the target point itself.
 973fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 974    let mut row = 0;
 975    let mut offset = 0;
 976    for (ix, line) in s.split('\n').enumerate() {
 977        if ix > 0 {
 978            row += 1;
 979            offset += 1;
 980        }
 981        if row >= target {
 982            break;
 983        }
 984        offset += line.len() as usize;
 985    }
 986    (row, offset)
 987}
 988
 989#[cfg(test)]
 990mod tests {
 991    use super::*;
 992    use crate::display_map::suggestion_map::SuggestionMap;
 993    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 994    use crate::multi_buffer::MultiBuffer;
 995    use gpui::{elements::Empty, Element};
 996    use rand::prelude::*;
 997    use settings::SettingsStore;
 998    use std::env;
 999    use util::RandomCharIter;
1000
1001    #[gpui::test]
1002    fn test_offset_for_row() {
1003        assert_eq!(offset_for_row("", 0), (0, 0));
1004        assert_eq!(offset_for_row("", 1), (0, 0));
1005        assert_eq!(offset_for_row("abcd", 0), (0, 0));
1006        assert_eq!(offset_for_row("abcd", 1), (0, 4));
1007        assert_eq!(offset_for_row("\n", 0), (0, 0));
1008        assert_eq!(offset_for_row("\n", 1), (1, 1));
1009        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
1010        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
1011        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
1012        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
1013    }
1014
1015    #[gpui::test]
1016    fn test_basic_blocks(cx: &mut gpui::AppContext) {
1017        init_test(cx);
1018
1019        let family_id = cx
1020            .font_cache()
1021            .load_family(&["Helvetica"], &Default::default())
1022            .unwrap();
1023        let font_id = cx
1024            .font_cache()
1025            .select_font(family_id, &Default::default())
1026            .unwrap();
1027
1028        let text = "aaa\nbbb\nccc\nddd";
1029
1030        let buffer = MultiBuffer::build_simple(text, cx);
1031        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1032        let subscription = buffer.update(cx, |buffer, _| buffer.subscribe());
1033        let (fold_map, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
1034        let (suggestion_map, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
1035        let (tab_map, tab_snapshot) = TabMap::new(suggestion_snapshot, 1.try_into().unwrap());
1036        let (wrap_map, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, None, cx);
1037        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1038
1039        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1040        let block_ids = writer.insert(vec![
1041            BlockProperties {
1042                style: BlockStyle::Fixed,
1043                position: buffer_snapshot.anchor_after(Point::new(1, 0)),
1044                height: 1,
1045                disposition: BlockDisposition::Above,
1046                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1047            },
1048            BlockProperties {
1049                style: BlockStyle::Fixed,
1050                position: buffer_snapshot.anchor_after(Point::new(1, 2)),
1051                height: 2,
1052                disposition: BlockDisposition::Above,
1053                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1054            },
1055            BlockProperties {
1056                style: BlockStyle::Fixed,
1057                position: buffer_snapshot.anchor_after(Point::new(3, 3)),
1058                height: 3,
1059                disposition: BlockDisposition::Below,
1060                render: Arc::new(|_| Empty::new().into_any_named("block 3")),
1061            },
1062        ]);
1063
1064        let snapshot = block_map.read(wraps_snapshot, Default::default());
1065        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
1066
1067        let blocks = snapshot
1068            .blocks_in_range(0..8)
1069            .map(|(start_row, block)| {
1070                let block = block.as_custom().unwrap();
1071                (start_row..start_row + block.height as u32, block.id)
1072            })
1073            .collect::<Vec<_>>();
1074
1075        // When multiple blocks are on the same line, the newer blocks appear first.
1076        assert_eq!(
1077            blocks,
1078            &[
1079                (1..2, block_ids[0]),
1080                (2..4, block_ids[1]),
1081                (7..10, block_ids[2]),
1082            ]
1083        );
1084
1085        assert_eq!(
1086            snapshot.to_block_point(WrapPoint::new(0, 3)),
1087            BlockPoint::new(0, 3)
1088        );
1089        assert_eq!(
1090            snapshot.to_block_point(WrapPoint::new(1, 0)),
1091            BlockPoint::new(4, 0)
1092        );
1093        assert_eq!(
1094            snapshot.to_block_point(WrapPoint::new(3, 3)),
1095            BlockPoint::new(6, 3)
1096        );
1097
1098        assert_eq!(
1099            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
1100            WrapPoint::new(0, 3)
1101        );
1102        assert_eq!(
1103            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
1104            WrapPoint::new(1, 0)
1105        );
1106        assert_eq!(
1107            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
1108            WrapPoint::new(1, 0)
1109        );
1110        assert_eq!(
1111            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
1112            WrapPoint::new(3, 3)
1113        );
1114
1115        assert_eq!(
1116            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
1117            BlockPoint::new(0, 3)
1118        );
1119        assert_eq!(
1120            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
1121            BlockPoint::new(4, 0)
1122        );
1123        assert_eq!(
1124            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1125            BlockPoint::new(0, 3)
1126        );
1127        assert_eq!(
1128            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1129            BlockPoint::new(4, 0)
1130        );
1131        assert_eq!(
1132            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1133            BlockPoint::new(4, 0)
1134        );
1135        assert_eq!(
1136            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1137            BlockPoint::new(4, 0)
1138        );
1139        assert_eq!(
1140            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1141            BlockPoint::new(6, 3)
1142        );
1143        assert_eq!(
1144            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1145            BlockPoint::new(6, 3)
1146        );
1147        assert_eq!(
1148            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1149            BlockPoint::new(6, 3)
1150        );
1151        assert_eq!(
1152            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1153            BlockPoint::new(6, 3)
1154        );
1155
1156        assert_eq!(
1157            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1158            &[
1159                Some(0),
1160                None,
1161                None,
1162                None,
1163                Some(1),
1164                Some(2),
1165                Some(3),
1166                None,
1167                None,
1168                None
1169            ]
1170        );
1171
1172        // Insert a line break, separating two block decorations into separate lines.
1173        let buffer_snapshot = buffer.update(cx, |buffer, cx| {
1174            buffer.edit([(Point::new(1, 1)..Point::new(1, 1), "!!!\n")], None, cx);
1175            buffer.snapshot(cx)
1176        });
1177
1178        let (fold_snapshot, fold_edits) =
1179            fold_map.read(buffer_snapshot, subscription.consume().into_inner());
1180        let (suggestion_snapshot, suggestion_edits) =
1181            suggestion_map.sync(fold_snapshot, fold_edits);
1182        let (tab_snapshot, tab_edits) =
1183            tab_map.sync(suggestion_snapshot, suggestion_edits, 4.try_into().unwrap());
1184        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1185            wrap_map.sync(tab_snapshot, tab_edits, cx)
1186        });
1187        let snapshot = block_map.read(wraps_snapshot, wrap_edits);
1188        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1189    }
1190
1191    #[gpui::test]
1192    fn test_blocks_on_wrapped_lines(cx: &mut gpui::AppContext) {
1193        init_test(cx);
1194
1195        let family_id = cx
1196            .font_cache()
1197            .load_family(&["Helvetica"], &Default::default())
1198            .unwrap();
1199        let font_id = cx
1200            .font_cache()
1201            .select_font(family_id, &Default::default())
1202            .unwrap();
1203
1204        let text = "one two three\nfour five six\nseven eight";
1205
1206        let buffer = MultiBuffer::build_simple(text, cx);
1207        let buffer_snapshot = buffer.read(cx).snapshot(cx);
1208        let (_, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
1209        let (_, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
1210        let (_, tab_snapshot) = TabMap::new(suggestion_snapshot, 1.try_into().unwrap());
1211        let (_, wraps_snapshot) = WrapMap::new(tab_snapshot, font_id, 14.0, Some(60.), cx);
1212        let mut block_map = BlockMap::new(wraps_snapshot.clone(), 1, 1);
1213
1214        let mut writer = block_map.write(wraps_snapshot.clone(), Default::default());
1215        writer.insert(vec![
1216            BlockProperties {
1217                style: BlockStyle::Fixed,
1218                position: buffer_snapshot.anchor_after(Point::new(1, 12)),
1219                disposition: BlockDisposition::Above,
1220                render: Arc::new(|_| Empty::new().into_any_named("block 1")),
1221                height: 1,
1222            },
1223            BlockProperties {
1224                style: BlockStyle::Fixed,
1225                position: buffer_snapshot.anchor_after(Point::new(1, 1)),
1226                disposition: BlockDisposition::Below,
1227                render: Arc::new(|_| Empty::new().into_any_named("block 2")),
1228                height: 1,
1229            },
1230        ]);
1231
1232        // Blocks with an 'above' disposition go above their corresponding buffer line.
1233        // Blocks with a 'below' disposition go below their corresponding buffer line.
1234        let snapshot = block_map.read(wraps_snapshot, Default::default());
1235        assert_eq!(
1236            snapshot.text(),
1237            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1238        );
1239    }
1240
1241    #[gpui::test(iterations = 100)]
1242    fn test_random_blocks(cx: &mut gpui::AppContext, mut rng: StdRng) {
1243        init_test(cx);
1244
1245        let operations = env::var("OPERATIONS")
1246            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1247            .unwrap_or(10);
1248
1249        let wrap_width = if rng.gen_bool(0.2) {
1250            None
1251        } else {
1252            Some(rng.gen_range(0.0..=100.0))
1253        };
1254        let tab_size = 1.try_into().unwrap();
1255        let family_id = cx
1256            .font_cache()
1257            .load_family(&["Helvetica"], &Default::default())
1258            .unwrap();
1259        let font_id = cx
1260            .font_cache()
1261            .select_font(family_id, &Default::default())
1262            .unwrap();
1263        let font_size = 14.0;
1264        let buffer_start_header_height = rng.gen_range(1..=5);
1265        let excerpt_header_height = rng.gen_range(1..=5);
1266
1267        log::info!("Wrap width: {:?}", wrap_width);
1268        log::info!("Excerpt Header Height: {:?}", excerpt_header_height);
1269
1270        let buffer = if rng.gen() {
1271            let len = rng.gen_range(0..10);
1272            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1273            log::info!("initial buffer text: {:?}", text);
1274            MultiBuffer::build_simple(&text, cx)
1275        } else {
1276            MultiBuffer::build_random(&mut rng, cx)
1277        };
1278
1279        let mut buffer_snapshot = buffer.read(cx).snapshot(cx);
1280        let (fold_map, fold_snapshot) = FoldMap::new(buffer_snapshot.clone());
1281        let (suggestion_map, suggestion_snapshot) = SuggestionMap::new(fold_snapshot);
1282        let (tab_map, tab_snapshot) = TabMap::new(suggestion_snapshot, tab_size);
1283        let (wrap_map, wraps_snapshot) =
1284            WrapMap::new(tab_snapshot, font_id, font_size, wrap_width, cx);
1285        let mut block_map = BlockMap::new(
1286            wraps_snapshot,
1287            buffer_start_header_height,
1288            excerpt_header_height,
1289        );
1290        let mut custom_blocks = Vec::new();
1291
1292        for _ in 0..operations {
1293            let mut buffer_edits = Vec::new();
1294            match rng.gen_range(0..=100) {
1295                0..=19 => {
1296                    let wrap_width = if rng.gen_bool(0.2) {
1297                        None
1298                    } else {
1299                        Some(rng.gen_range(0.0..=100.0))
1300                    };
1301                    log::info!("Setting wrap width to {:?}", wrap_width);
1302                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1303                }
1304                20..=39 => {
1305                    let block_count = rng.gen_range(1..=5);
1306                    let block_properties = (0..block_count)
1307                        .map(|_| {
1308                            let buffer = buffer.read(cx).read(cx);
1309                            let position = buffer.anchor_after(
1310                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1311                            );
1312
1313                            let disposition = if rng.gen() {
1314                                BlockDisposition::Above
1315                            } else {
1316                                BlockDisposition::Below
1317                            };
1318                            let height = rng.gen_range(1..5);
1319                            log::info!(
1320                                "inserting block {:?} {:?} with height {}",
1321                                disposition,
1322                                position.to_point(&buffer),
1323                                height
1324                            );
1325                            BlockProperties {
1326                                style: BlockStyle::Fixed,
1327                                position,
1328                                height,
1329                                disposition,
1330                                render: Arc::new(|_| Empty::new().into_any()),
1331                            }
1332                        })
1333                        .collect::<Vec<_>>();
1334
1335                    let (fold_snapshot, fold_edits) =
1336                        fold_map.read(buffer_snapshot.clone(), vec![]);
1337                    let (suggestion_snapshot, suggestion_edits) =
1338                        suggestion_map.sync(fold_snapshot, fold_edits);
1339                    let (tab_snapshot, tab_edits) =
1340                        tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1341                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1342                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1343                    });
1344                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1345                    let block_ids = block_map.insert(block_properties.clone());
1346                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1347                        custom_blocks.push((block_id, props));
1348                    }
1349                }
1350                40..=59 if !custom_blocks.is_empty() => {
1351                    let block_count = rng.gen_range(1..=4.min(custom_blocks.len()));
1352                    let block_ids_to_remove = (0..block_count)
1353                        .map(|_| {
1354                            custom_blocks
1355                                .remove(rng.gen_range(0..custom_blocks.len()))
1356                                .0
1357                        })
1358                        .collect();
1359
1360                    let (fold_snapshot, fold_edits) =
1361                        fold_map.read(buffer_snapshot.clone(), vec![]);
1362                    let (suggestion_snapshot, suggestion_edits) =
1363                        suggestion_map.sync(fold_snapshot, fold_edits);
1364                    let (tab_snapshot, tab_edits) =
1365                        tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1366                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1367                        wrap_map.sync(tab_snapshot, tab_edits, cx)
1368                    });
1369                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits);
1370                    block_map.remove(block_ids_to_remove);
1371                }
1372                _ => {
1373                    buffer.update(cx, |buffer, cx| {
1374                        let mutation_count = rng.gen_range(1..=5);
1375                        let subscription = buffer.subscribe();
1376                        buffer.randomly_mutate(&mut rng, mutation_count, cx);
1377                        buffer_snapshot = buffer.snapshot(cx);
1378                        buffer_edits.extend(subscription.consume());
1379                        log::info!("buffer text: {:?}", buffer_snapshot.text());
1380                    });
1381                }
1382            }
1383
1384            let (fold_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1385            let (suggestion_snapshot, suggestion_edits) =
1386                suggestion_map.sync(fold_snapshot, fold_edits);
1387            let (tab_snapshot, tab_edits) =
1388                tab_map.sync(suggestion_snapshot, suggestion_edits, tab_size);
1389            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1390                wrap_map.sync(tab_snapshot, tab_edits, cx)
1391            });
1392            let blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits);
1393            assert_eq!(
1394                blocks_snapshot.transforms.summary().input_rows,
1395                wraps_snapshot.max_point().row() + 1
1396            );
1397            log::info!("blocks text: {:?}", blocks_snapshot.text());
1398
1399            let mut expected_blocks = Vec::new();
1400            expected_blocks.extend(custom_blocks.iter().map(|(id, block)| {
1401                let mut position = block.position.to_point(&buffer_snapshot);
1402                match block.disposition {
1403                    BlockDisposition::Above => {
1404                        position.column = 0;
1405                    }
1406                    BlockDisposition::Below => {
1407                        position.column = buffer_snapshot.line_len(position.row);
1408                    }
1409                };
1410                let row = wraps_snapshot.make_wrap_point(position, Bias::Left).row();
1411                (
1412                    row,
1413                    ExpectedBlock::Custom {
1414                        disposition: block.disposition,
1415                        id: *id,
1416                        height: block.height,
1417                    },
1418                )
1419            }));
1420            expected_blocks.extend(buffer_snapshot.excerpt_boundaries_in_range(0..).map(
1421                |boundary| {
1422                    let position =
1423                        wraps_snapshot.make_wrap_point(Point::new(boundary.row, 0), Bias::Left);
1424                    (
1425                        position.row(),
1426                        ExpectedBlock::ExcerptHeader {
1427                            height: if boundary.starts_new_buffer {
1428                                buffer_start_header_height
1429                            } else {
1430                                excerpt_header_height
1431                            },
1432                            starts_new_buffer: boundary.starts_new_buffer,
1433                        },
1434                    )
1435                },
1436            ));
1437            expected_blocks.sort_unstable();
1438            let mut sorted_blocks_iter = expected_blocks.into_iter().peekable();
1439
1440            let input_buffer_rows = buffer_snapshot.buffer_rows(0).collect::<Vec<_>>();
1441            let mut expected_buffer_rows = Vec::new();
1442            let mut expected_text = String::new();
1443            let mut expected_block_positions = Vec::new();
1444            let input_text = wraps_snapshot.text();
1445            for (row, input_line) in input_text.split('\n').enumerate() {
1446                let row = row as u32;
1447                if row > 0 {
1448                    expected_text.push('\n');
1449                }
1450
1451                let buffer_row = input_buffer_rows[wraps_snapshot
1452                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1453                    .row as usize];
1454
1455                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1456                    if *block_row == row && block.disposition() == BlockDisposition::Above {
1457                        let (_, block) = sorted_blocks_iter.next().unwrap();
1458                        let height = block.height() as usize;
1459                        expected_block_positions
1460                            .push((expected_text.matches('\n').count() as u32, block));
1461                        let text = "\n".repeat(height);
1462                        expected_text.push_str(&text);
1463                        for _ in 0..height {
1464                            expected_buffer_rows.push(None);
1465                        }
1466                    } else {
1467                        break;
1468                    }
1469                }
1470
1471                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1472                expected_buffer_rows.push(if soft_wrapped { None } else { buffer_row });
1473                expected_text.push_str(input_line);
1474
1475                while let Some((block_row, block)) = sorted_blocks_iter.peek() {
1476                    if *block_row == row && block.disposition() == BlockDisposition::Below {
1477                        let (_, block) = sorted_blocks_iter.next().unwrap();
1478                        let height = block.height() as usize;
1479                        expected_block_positions
1480                            .push((expected_text.matches('\n').count() as u32 + 1, block));
1481                        let text = "\n".repeat(height);
1482                        expected_text.push_str(&text);
1483                        for _ in 0..height {
1484                            expected_buffer_rows.push(None);
1485                        }
1486                    } else {
1487                        break;
1488                    }
1489                }
1490            }
1491
1492            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1493            let expected_row_count = expected_lines.len();
1494            for start_row in 0..expected_row_count {
1495                let expected_text = expected_lines[start_row..].join("\n");
1496                let actual_text = blocks_snapshot
1497                    .chunks(
1498                        start_row as u32..blocks_snapshot.max_point().row + 1,
1499                        false,
1500                        None,
1501                        None,
1502                    )
1503                    .map(|chunk| chunk.text)
1504                    .collect::<String>();
1505                assert_eq!(
1506                    actual_text, expected_text,
1507                    "incorrect text starting from row {}",
1508                    start_row
1509                );
1510                assert_eq!(
1511                    blocks_snapshot
1512                        .buffer_rows(start_row as u32)
1513                        .collect::<Vec<_>>(),
1514                    &expected_buffer_rows[start_row..]
1515                );
1516            }
1517
1518            assert_eq!(
1519                blocks_snapshot
1520                    .blocks_in_range(0..(expected_row_count as u32))
1521                    .map(|(row, block)| (row, block.clone().into()))
1522                    .collect::<Vec<_>>(),
1523                expected_block_positions
1524            );
1525
1526            let mut expected_longest_rows = Vec::new();
1527            let mut longest_line_len = -1_isize;
1528            for (row, line) in expected_lines.iter().enumerate() {
1529                let row = row as u32;
1530
1531                assert_eq!(
1532                    blocks_snapshot.line_len(row),
1533                    line.len() as u32,
1534                    "invalid line len for row {}",
1535                    row
1536                );
1537
1538                let line_char_count = line.chars().count() as isize;
1539                match line_char_count.cmp(&longest_line_len) {
1540                    Ordering::Less => {}
1541                    Ordering::Equal => expected_longest_rows.push(row),
1542                    Ordering::Greater => {
1543                        longest_line_len = line_char_count;
1544                        expected_longest_rows.clear();
1545                        expected_longest_rows.push(row);
1546                    }
1547                }
1548            }
1549
1550            let longest_row = blocks_snapshot.longest_row();
1551            assert!(
1552                expected_longest_rows.contains(&longest_row),
1553                "incorrect longest row {}. expected {:?} with length {}",
1554                longest_row,
1555                expected_longest_rows,
1556                longest_line_len,
1557            );
1558
1559            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1560                let wrap_point = WrapPoint::new(row, 0);
1561                let block_point = blocks_snapshot.to_block_point(wrap_point);
1562                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1563            }
1564
1565            let mut block_point = BlockPoint::new(0, 0);
1566            for c in expected_text.chars() {
1567                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1568                let left_buffer_point = blocks_snapshot.to_point(left_point, Bias::Left);
1569                assert_eq!(
1570                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1571                    left_point
1572                );
1573                assert_eq!(
1574                    left_buffer_point,
1575                    buffer_snapshot.clip_point(left_buffer_point, Bias::Right),
1576                    "{:?} is not valid in buffer coordinates",
1577                    left_point
1578                );
1579
1580                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1581                let right_buffer_point = blocks_snapshot.to_point(right_point, Bias::Right);
1582                assert_eq!(
1583                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1584                    right_point
1585                );
1586                assert_eq!(
1587                    right_buffer_point,
1588                    buffer_snapshot.clip_point(right_buffer_point, Bias::Left),
1589                    "{:?} is not valid in buffer coordinates",
1590                    right_point
1591                );
1592
1593                if c == '\n' {
1594                    block_point.0 += Point::new(1, 0);
1595                } else {
1596                    block_point.column += c.len_utf8() as u32;
1597                }
1598            }
1599        }
1600
1601        #[derive(Debug, Eq, PartialEq, Ord, PartialOrd)]
1602        enum ExpectedBlock {
1603            ExcerptHeader {
1604                height: u8,
1605                starts_new_buffer: bool,
1606            },
1607            Custom {
1608                disposition: BlockDisposition,
1609                id: BlockId,
1610                height: u8,
1611            },
1612        }
1613
1614        impl ExpectedBlock {
1615            fn height(&self) -> u8 {
1616                match self {
1617                    ExpectedBlock::ExcerptHeader { height, .. } => *height,
1618                    ExpectedBlock::Custom { height, .. } => *height,
1619                }
1620            }
1621
1622            fn disposition(&self) -> BlockDisposition {
1623                match self {
1624                    ExpectedBlock::ExcerptHeader { .. } => BlockDisposition::Above,
1625                    ExpectedBlock::Custom { disposition, .. } => *disposition,
1626                }
1627            }
1628        }
1629
1630        impl From<TransformBlock> for ExpectedBlock {
1631            fn from(block: TransformBlock) -> Self {
1632                match block {
1633                    TransformBlock::Custom(block) => ExpectedBlock::Custom {
1634                        id: block.id,
1635                        disposition: block.disposition,
1636                        height: block.height,
1637                    },
1638                    TransformBlock::ExcerptHeader {
1639                        height,
1640                        starts_new_buffer,
1641                        ..
1642                    } => ExpectedBlock::ExcerptHeader {
1643                        height,
1644                        starts_new_buffer,
1645                    },
1646                }
1647            }
1648        }
1649    }
1650
1651    fn init_test(cx: &mut gpui::AppContext) {
1652        cx.set_global(SettingsStore::test(cx));
1653        theme::init((), cx);
1654    }
1655
1656    impl TransformBlock {
1657        fn as_custom(&self) -> Option<&Block> {
1658            match self {
1659                TransformBlock::Custom(block) => Some(block),
1660                TransformBlock::ExcerptHeader { .. } => None,
1661            }
1662        }
1663    }
1664
1665    impl BlockSnapshot {
1666        fn to_point(&self, point: BlockPoint, bias: Bias) -> Point {
1667            self.wrap_snapshot.to_point(self.to_wrap_point(point), bias)
1668        }
1669    }
1670}