block_map.rs

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