block_map.rs

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