1use super::wrap_map::{self, Edit as WrapEdit, Snapshot as WrapSnapshot, WrapPoint};
   2use gpui::{AppContext, ElementBox, ModelHandle};
   3use language::{Buffer, Chunk};
   4use parking_lot::Mutex;
   5use std::{
   6    cmp::{self, Ordering},
   7    collections::{HashMap, HashSet},
   8    fmt::Debug,
   9    ops::{Deref, Range},
  10    sync::{
  11        atomic::{AtomicUsize, Ordering::SeqCst},
  12        Arc,
  13    },
  14};
  15use sum_tree::SumTree;
  16use text::{Anchor, Bias, Edit, Point, ToOffset, ToPoint as _};
  17use theme::SyntaxTheme;
  18
  19const NEWLINES: &'static [u8] = &[b'\n'; u8::MAX as usize];
  20
  21pub struct BlockMap {
  22    buffer: ModelHandle<Buffer>,
  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 struct Block {
  49    id: BlockId,
  50    position: Anchor,
  51    height: u8,
  52    render: Mutex<Arc<dyn Fn(&BlockContext) -> ElementBox>>,
  53    disposition: BlockDisposition,
  54}
  55
  56#[derive(Clone)]
  57pub struct BlockProperties<P>
  58where
  59    P: Clone,
  60{
  61    pub position: P,
  62    pub height: u8,
  63    pub render: Arc<dyn Fn(&BlockContext) -> ElementBox>,
  64    pub disposition: BlockDisposition,
  65}
  66
  67pub struct BlockContext<'a> {
  68    pub cx: &'a AppContext,
  69    pub anchor_x: f32,
  70}
  71
  72#[derive(Clone, Copy, Debug, PartialEq, Eq, PartialOrd, Ord)]
  73pub enum BlockDisposition {
  74    Above,
  75    Below,
  76}
  77
  78#[derive(Clone, Debug)]
  79struct Transform {
  80    summary: TransformSummary,
  81    block: Option<AlignedBlock>,
  82}
  83
  84#[derive(Clone, Debug)]
  85pub struct AlignedBlock {
  86    block: Arc<Block>,
  87    column: u32,
  88}
  89
  90#[derive(Clone, Debug, Default)]
  91struct TransformSummary {
  92    input_rows: u32,
  93    output_rows: u32,
  94}
  95
  96pub struct Chunks<'a> {
  97    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
  98    input_chunks: wrap_map::Chunks<'a>,
  99    input_chunk: Chunk<'a>,
 100    output_row: u32,
 101    max_output_row: u32,
 102}
 103
 104pub struct BufferRows<'a> {
 105    transforms: sum_tree::Cursor<'a, Transform, (BlockRow, WrapRow)>,
 106    input_buffer_rows: wrap_map::BufferRows<'a>,
 107    output_row: u32,
 108    started: bool,
 109}
 110
 111impl BlockMap {
 112    pub fn new(buffer: ModelHandle<Buffer>, wrap_snapshot: WrapSnapshot) -> Self {
 113        Self {
 114            buffer,
 115            next_block_id: AtomicUsize::new(0),
 116            blocks: Vec::new(),
 117            transforms: Mutex::new(SumTree::from_item(
 118                Transform::isomorphic(wrap_snapshot.text_summary().lines.row + 1),
 119                &(),
 120            )),
 121            wrap_snapshot: Mutex::new(wrap_snapshot),
 122        }
 123    }
 124
 125    pub fn read(
 126        &self,
 127        wrap_snapshot: WrapSnapshot,
 128        edits: Vec<WrapEdit>,
 129        cx: &AppContext,
 130    ) -> BlockSnapshot {
 131        self.sync(&wrap_snapshot, edits, cx);
 132        *self.wrap_snapshot.lock() = wrap_snapshot.clone();
 133        BlockSnapshot {
 134            wrap_snapshot,
 135            transforms: self.transforms.lock().clone(),
 136        }
 137    }
 138
 139    pub fn write(
 140        &mut self,
 141        wrap_snapshot: WrapSnapshot,
 142        edits: Vec<WrapEdit>,
 143        cx: &AppContext,
 144    ) -> BlockMapWriter {
 145        self.sync(&wrap_snapshot, edits, cx);
 146        *self.wrap_snapshot.lock() = wrap_snapshot;
 147        BlockMapWriter(self)
 148    }
 149
 150    fn sync(&self, wrap_snapshot: &WrapSnapshot, edits: Vec<WrapEdit>, cx: &AppContext) {
 151        if edits.is_empty() {
 152            return;
 153        }
 154
 155        let buffer = self.buffer.read(cx);
 156        let mut transforms = self.transforms.lock();
 157        let mut new_transforms = SumTree::new();
 158        let old_row_count = transforms.summary().input_rows;
 159        let new_row_count = wrap_snapshot.max_point().row() + 1;
 160        let mut cursor = transforms.cursor::<WrapRow>();
 161        let mut last_block_ix = 0;
 162        let mut blocks_in_edit = Vec::new();
 163        let mut edits = edits.into_iter().peekable();
 164
 165        while let Some(edit) = edits.next() {
 166            // Preserve any old transforms that precede this edit.
 167            let old_start = WrapRow(edit.old.start);
 168            let new_start = WrapRow(edit.new.start);
 169            new_transforms.push_tree(cursor.slice(&old_start, Bias::Left, &()), &());
 170            if let Some(transform) = cursor.item() {
 171                if transform.is_isomorphic() && old_start == cursor.end(&()) {
 172                    new_transforms.push(transform.clone(), &());
 173                    cursor.next(&());
 174                    while let Some(transform) = cursor.item() {
 175                        if transform
 176                            .block
 177                            .as_ref()
 178                            .map_or(false, |b| b.disposition.is_below())
 179                        {
 180                            new_transforms.push(transform.clone(), &());
 181                            cursor.next(&());
 182                        } else {
 183                            break;
 184                        }
 185                    }
 186                }
 187            }
 188
 189            // Preserve any portion of an old transform that precedes this edit.
 190            let extent_before_edit = old_start.0 - cursor.start().0;
 191            push_isomorphic(&mut new_transforms, extent_before_edit);
 192
 193            // Skip over any old transforms that intersect this edit.
 194            let mut old_end = WrapRow(edit.old.end);
 195            let mut new_end = WrapRow(edit.new.end);
 196            cursor.seek(&old_end, Bias::Left, &());
 197            cursor.next(&());
 198            if old_end == *cursor.start() {
 199                while let Some(transform) = cursor.item() {
 200                    if transform
 201                        .block
 202                        .as_ref()
 203                        .map_or(false, |b| b.disposition.is_below())
 204                    {
 205                        cursor.next(&());
 206                    } else {
 207                        break;
 208                    }
 209                }
 210            }
 211
 212            // Combine this edit with any subsequent edits that intersect the same transform.
 213            while let Some(next_edit) = edits.peek() {
 214                if next_edit.old.start <= cursor.start().0 {
 215                    old_end = WrapRow(next_edit.old.end);
 216                    new_end = WrapRow(next_edit.new.end);
 217                    cursor.seek(&old_end, Bias::Left, &());
 218                    cursor.next(&());
 219                    if old_end == *cursor.start() {
 220                        while let Some(transform) = cursor.item() {
 221                            if transform
 222                                .block
 223                                .as_ref()
 224                                .map_or(false, |b| b.disposition.is_below())
 225                            {
 226                                cursor.next(&());
 227                            } else {
 228                                break;
 229                            }
 230                        }
 231                    }
 232                    edits.next();
 233                } else {
 234                    break;
 235                }
 236            }
 237
 238            // Find the blocks within this edited region.
 239            let new_start = wrap_snapshot.to_point(WrapPoint::new(new_start.0, 0), Bias::Left);
 240            let start_anchor = buffer.anchor_before(new_start);
 241            let start_block_ix = match self.blocks[last_block_ix..].binary_search_by(|probe| {
 242                probe
 243                    .position
 244                    .cmp(&start_anchor, buffer)
 245                    .unwrap()
 246                    .then(Ordering::Greater)
 247            }) {
 248                Ok(ix) | Err(ix) => last_block_ix + ix,
 249            };
 250            let end_block_ix = if new_end.0 > wrap_snapshot.max_point().row() {
 251                self.blocks.len()
 252            } else {
 253                let new_end = wrap_snapshot.to_point(WrapPoint::new(new_end.0, 0), Bias::Left);
 254                let end_anchor = buffer.anchor_before(new_end);
 255                match self.blocks[start_block_ix..].binary_search_by(|probe| {
 256                    probe
 257                        .position
 258                        .cmp(&end_anchor, buffer)
 259                        .unwrap()
 260                        .then(Ordering::Greater)
 261                }) {
 262                    Ok(ix) | Err(ix) => start_block_ix + ix,
 263                }
 264            };
 265            last_block_ix = end_block_ix;
 266            blocks_in_edit.clear();
 267            blocks_in_edit.extend(
 268                self.blocks[start_block_ix..end_block_ix]
 269                    .iter()
 270                    .map(|block| {
 271                        let mut position = block.position.to_point(buffer);
 272                        let column = wrap_snapshot.from_point(position, Bias::Left).column();
 273                        match block.disposition {
 274                            BlockDisposition::Above => position.column = 0,
 275                            BlockDisposition::Below => {
 276                                position.column = buffer.line_len(position.row)
 277                            }
 278                        }
 279                        let position = wrap_snapshot.from_point(position, Bias::Left);
 280                        (position.row(), column, block)
 281                    }),
 282            );
 283            blocks_in_edit
 284                .sort_unstable_by_key(|(row, _, block)| (*row, block.disposition, block.id));
 285
 286            // For each of these blocks, insert a new isomorphic transform preceding the block,
 287            // and then insert the block itself.
 288            for (block_row, column, block) in blocks_in_edit.iter().copied() {
 289                let insertion_row = match block.disposition {
 290                    BlockDisposition::Above => block_row,
 291                    BlockDisposition::Below => block_row + 1,
 292                };
 293                let extent_before_block = insertion_row - new_transforms.summary().input_rows;
 294                push_isomorphic(&mut new_transforms, extent_before_block);
 295                new_transforms.push(Transform::block(block.clone(), column), &());
 296            }
 297
 298            old_end = WrapRow(old_end.0.min(old_row_count));
 299            new_end = WrapRow(new_end.0.min(new_row_count));
 300
 301            // Insert an isomorphic transform after the final block.
 302            let extent_after_last_block = new_end.0 - new_transforms.summary().input_rows;
 303            push_isomorphic(&mut new_transforms, extent_after_last_block);
 304
 305            // Preserve any portion of the old transform after this edit.
 306            let extent_after_edit = cursor.start().0 - old_end.0;
 307            push_isomorphic(&mut new_transforms, extent_after_edit);
 308        }
 309
 310        new_transforms.push_tree(cursor.suffix(&()), &());
 311        debug_assert_eq!(
 312            new_transforms.summary().input_rows,
 313            wrap_snapshot.max_point().row() + 1
 314        );
 315
 316        drop(cursor);
 317        *transforms = new_transforms;
 318    }
 319
 320    pub fn replace<F>(&mut self, mut element_builders: HashMap<BlockId, F>)
 321    where
 322        F: 'static + Fn(&BlockContext) -> ElementBox,
 323    {
 324        for block in &self.blocks {
 325            if let Some(build_element) = element_builders.remove(&block.id) {
 326                *block.render.lock() = Arc::new(build_element);
 327            }
 328        }
 329    }
 330}
 331
 332fn push_isomorphic(tree: &mut SumTree<Transform>, rows: u32) {
 333    if rows == 0 {
 334        return;
 335    }
 336
 337    let mut extent = Some(rows);
 338    tree.update_last(
 339        |last_transform| {
 340            if last_transform.is_isomorphic() {
 341                let extent = extent.take().unwrap();
 342                last_transform.summary.input_rows += extent;
 343                last_transform.summary.output_rows += extent;
 344            }
 345        },
 346        &(),
 347    );
 348    if let Some(extent) = extent {
 349        tree.push(Transform::isomorphic(extent), &());
 350    }
 351}
 352
 353impl BlockPoint {
 354    pub fn new(row: u32, column: u32) -> Self {
 355        Self(Point::new(row, column))
 356    }
 357}
 358
 359impl Deref for BlockPoint {
 360    type Target = Point;
 361
 362    fn deref(&self) -> &Self::Target {
 363        &self.0
 364    }
 365}
 366
 367impl std::ops::DerefMut for BlockPoint {
 368    fn deref_mut(&mut self) -> &mut Self::Target {
 369        &mut self.0
 370    }
 371}
 372
 373impl<'a> BlockMapWriter<'a> {
 374    pub fn insert<P>(
 375        &mut self,
 376        blocks: impl IntoIterator<Item = BlockProperties<P>>,
 377        cx: &AppContext,
 378    ) -> Vec<BlockId>
 379    where
 380        P: ToOffset + Clone,
 381    {
 382        let buffer = self.0.buffer.read(cx);
 383        let mut ids = Vec::new();
 384        let mut edits = Vec::<Edit<u32>>::new();
 385        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 386
 387        for block in blocks {
 388            let id = BlockId(self.0.next_block_id.fetch_add(1, SeqCst));
 389            ids.push(id);
 390
 391            let position = buffer.anchor_after(block.position);
 392            let point = position.to_point(buffer);
 393            let start_row = wrap_snapshot
 394                .from_point(Point::new(point.row, 0), Bias::Left)
 395                .row();
 396            let end_row = if point.row == buffer.max_point().row {
 397                wrap_snapshot.max_point().row() + 1
 398            } else {
 399                wrap_snapshot
 400                    .from_point(Point::new(point.row + 1, 0), Bias::Left)
 401                    .row()
 402            };
 403
 404            let block_ix = match self
 405                .0
 406                .blocks
 407                .binary_search_by(|probe| probe.position.cmp(&position, buffer).unwrap())
 408            {
 409                Ok(ix) | Err(ix) => ix,
 410            };
 411            self.0.blocks.insert(
 412                block_ix,
 413                Arc::new(Block {
 414                    id,
 415                    position,
 416                    height: block.height,
 417                    render: Mutex::new(block.render),
 418                    disposition: block.disposition,
 419                }),
 420            );
 421
 422            if let Err(edit_ix) = edits.binary_search_by_key(&start_row, |edit| edit.old.start) {
 423                edits.insert(
 424                    edit_ix,
 425                    Edit {
 426                        old: start_row..end_row,
 427                        new: start_row..end_row,
 428                    },
 429                );
 430            }
 431        }
 432
 433        self.0.sync(wrap_snapshot, edits, cx);
 434        ids
 435    }
 436
 437    pub fn remove(&mut self, block_ids: HashSet<BlockId>, cx: &AppContext) {
 438        let buffer = self.0.buffer.read(cx);
 439        let wrap_snapshot = &*self.0.wrap_snapshot.lock();
 440        let mut edits = Vec::new();
 441        let mut last_block_buffer_row = None;
 442        self.0.blocks.retain(|block| {
 443            if block_ids.contains(&block.id) {
 444                let buffer_row = block.position.to_point(buffer).row;
 445                if last_block_buffer_row != Some(buffer_row) {
 446                    last_block_buffer_row = Some(buffer_row);
 447                    let start_row = wrap_snapshot
 448                        .from_point(Point::new(buffer_row, 0), Bias::Left)
 449                        .row();
 450                    let end_row = wrap_snapshot
 451                        .from_point(
 452                            Point::new(buffer_row, buffer.line_len(buffer_row)),
 453                            Bias::Left,
 454                        )
 455                        .row()
 456                        + 1;
 457                    edits.push(Edit {
 458                        old: start_row..end_row,
 459                        new: start_row..end_row,
 460                    })
 461                }
 462                false
 463            } else {
 464                true
 465            }
 466        });
 467        self.0.sync(wrap_snapshot, edits, cx);
 468    }
 469}
 470
 471impl BlockSnapshot {
 472    #[cfg(test)]
 473    fn text(&mut self) -> String {
 474        self.chunks(0..self.transforms.summary().output_rows, None)
 475            .map(|chunk| chunk.text)
 476            .collect()
 477    }
 478
 479    pub fn chunks<'a>(&'a self, rows: Range<u32>, theme: Option<&'a SyntaxTheme>) -> Chunks<'a> {
 480        let max_output_row = cmp::min(rows.end, self.transforms.summary().output_rows);
 481        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 482        let input_end = {
 483            cursor.seek(&BlockRow(rows.end), Bias::Right, &());
 484            let overshoot = if cursor
 485                .item()
 486                .map_or(false, |transform| transform.is_isomorphic())
 487            {
 488                rows.end - cursor.start().0 .0
 489            } else {
 490                0
 491            };
 492            cursor.start().1 .0 + overshoot
 493        };
 494        let input_start = {
 495            cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 496            let overshoot = if cursor
 497                .item()
 498                .map_or(false, |transform| transform.is_isomorphic())
 499            {
 500                rows.start - cursor.start().0 .0
 501            } else {
 502                0
 503            };
 504            cursor.start().1 .0 + overshoot
 505        };
 506        Chunks {
 507            input_chunks: self.wrap_snapshot.chunks(input_start..input_end, theme),
 508            input_chunk: Default::default(),
 509            transforms: cursor,
 510            output_row: rows.start,
 511            max_output_row,
 512        }
 513    }
 514
 515    pub fn buffer_rows<'a>(&'a self, start_row: u32) -> BufferRows<'a> {
 516        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 517        cursor.seek(&BlockRow(start_row), Bias::Right, &());
 518        let (output_start, input_start) = cursor.start();
 519        let overshoot = if cursor.item().map_or(false, |t| t.is_isomorphic()) {
 520            start_row - output_start.0
 521        } else {
 522            0
 523        };
 524        let input_start_row = input_start.0 + overshoot;
 525        BufferRows {
 526            transforms: cursor,
 527            input_buffer_rows: self.wrap_snapshot.buffer_rows(input_start_row),
 528            output_row: start_row,
 529            started: false,
 530        }
 531    }
 532
 533    pub fn blocks_in_range<'a>(
 534        &'a self,
 535        rows: Range<u32>,
 536    ) -> impl Iterator<Item = (u32, &'a AlignedBlock)> {
 537        let mut cursor = self.transforms.cursor::<BlockRow>();
 538        cursor.seek(&BlockRow(rows.start), Bias::Right, &());
 539        std::iter::from_fn(move || {
 540            while let Some(transform) = cursor.item() {
 541                let start_row = cursor.start().0;
 542                if start_row >= rows.end {
 543                    break;
 544                }
 545                if let Some(block) = &transform.block {
 546                    cursor.next(&());
 547                    return Some((start_row, block));
 548                } else {
 549                    cursor.next(&());
 550                }
 551            }
 552            None
 553        })
 554    }
 555
 556    pub fn max_point(&self) -> BlockPoint {
 557        let row = self.transforms.summary().output_rows - 1;
 558        BlockPoint::new(row, self.line_len(row))
 559    }
 560
 561    pub fn longest_row(&self) -> u32 {
 562        let input_row = self.wrap_snapshot.longest_row();
 563        self.to_block_point(WrapPoint::new(input_row, 0)).row
 564    }
 565
 566    pub fn line_len(&self, row: u32) -> u32 {
 567        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 568        cursor.seek(&BlockRow(row), Bias::Right, &());
 569        if let Some(transform) = cursor.item() {
 570            let (output_start, input_start) = cursor.start();
 571            let overshoot = row - output_start.0;
 572            if transform.block.is_some() {
 573                0
 574            } else {
 575                self.wrap_snapshot.line_len(input_start.0 + overshoot)
 576            }
 577        } else {
 578            panic!("row out of range");
 579        }
 580    }
 581
 582    pub fn is_block_line(&self, row: u32) -> bool {
 583        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 584        cursor.seek(&BlockRow(row), Bias::Right, &());
 585        cursor.item().map_or(false, |t| t.block.is_some())
 586    }
 587
 588    pub fn clip_point(&self, point: BlockPoint, bias: Bias) -> BlockPoint {
 589        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 590        cursor.seek(&BlockRow(point.row), Bias::Right, &());
 591
 592        let max_input_row = WrapRow(self.transforms.summary().input_rows);
 593        let search_left =
 594            (bias == Bias::Left && cursor.start().1 .0 > 0) || cursor.end(&()).1 == max_input_row;
 595
 596        loop {
 597            if let Some(transform) = cursor.item() {
 598                if transform.is_isomorphic() {
 599                    let (output_start_row, input_start_row) = cursor.start();
 600                    let (output_end_row, input_end_row) = cursor.end(&());
 601
 602                    if point.row >= output_end_row.0 {
 603                        return BlockPoint::new(
 604                            output_end_row.0 - 1,
 605                            self.wrap_snapshot.line_len(input_end_row.0 - 1),
 606                        );
 607                    }
 608
 609                    let output_start = Point::new(output_start_row.0, 0);
 610                    if point.0 > output_start {
 611                        let output_overshoot = point.0 - output_start;
 612                        let input_start = Point::new(input_start_row.0, 0);
 613                        let input_point = self
 614                            .wrap_snapshot
 615                            .clip_point(WrapPoint(input_start + output_overshoot), bias);
 616                        let input_overshoot = input_point.0 - input_start;
 617                        return BlockPoint(output_start + input_overshoot);
 618                    } else {
 619                        return BlockPoint(output_start);
 620                    }
 621                } else if search_left {
 622                    cursor.prev(&());
 623                } else {
 624                    cursor.next(&());
 625                }
 626            } else {
 627                return self.max_point();
 628            }
 629        }
 630    }
 631
 632    pub fn to_block_point(&self, wrap_point: WrapPoint) -> BlockPoint {
 633        let mut cursor = self.transforms.cursor::<(WrapRow, BlockRow)>();
 634        cursor.seek(&WrapRow(wrap_point.row()), Bias::Right, &());
 635        if let Some(transform) = cursor.item() {
 636            debug_assert!(transform.is_isomorphic());
 637        } else {
 638            return self.max_point();
 639        }
 640
 641        let (input_start_row, output_start_row) = cursor.start();
 642        let input_start = Point::new(input_start_row.0, 0);
 643        let output_start = Point::new(output_start_row.0, 0);
 644        let input_overshoot = wrap_point.0 - input_start;
 645        BlockPoint(output_start + input_overshoot)
 646    }
 647
 648    pub fn to_wrap_point(&self, block_point: BlockPoint) -> WrapPoint {
 649        let mut cursor = self.transforms.cursor::<(BlockRow, WrapRow)>();
 650        cursor.seek(&BlockRow(block_point.row), Bias::Right, &());
 651        if let Some(transform) = cursor.item() {
 652            match transform.block.as_ref().map(|b| b.disposition) {
 653                Some(BlockDisposition::Above) => WrapPoint::new(cursor.start().1 .0, 0),
 654                Some(BlockDisposition::Below) => {
 655                    let wrap_row = cursor.start().1 .0 - 1;
 656                    WrapPoint::new(wrap_row, self.wrap_snapshot.line_len(wrap_row))
 657                }
 658                None => {
 659                    let overshoot = block_point.row - cursor.start().0 .0;
 660                    let wrap_row = cursor.start().1 .0 + overshoot;
 661                    WrapPoint::new(wrap_row, block_point.column)
 662                }
 663            }
 664        } else {
 665            self.wrap_snapshot.max_point()
 666        }
 667    }
 668}
 669
 670impl Transform {
 671    fn isomorphic(rows: u32) -> Self {
 672        Self {
 673            summary: TransformSummary {
 674                input_rows: rows,
 675                output_rows: rows,
 676            },
 677            block: None,
 678        }
 679    }
 680
 681    fn block(block: Arc<Block>, column: u32) -> Self {
 682        Self {
 683            summary: TransformSummary {
 684                input_rows: 0,
 685                output_rows: block.height as u32,
 686            },
 687            block: Some(AlignedBlock { block, column }),
 688        }
 689    }
 690
 691    fn is_isomorphic(&self) -> bool {
 692        self.block.is_none()
 693    }
 694}
 695
 696impl<'a> Iterator for Chunks<'a> {
 697    type Item = Chunk<'a>;
 698
 699    fn next(&mut self) -> Option<Self::Item> {
 700        if self.output_row >= self.max_output_row {
 701            return None;
 702        }
 703
 704        let transform = self.transforms.item()?;
 705        if transform.block.is_some() {
 706            let block_start = self.transforms.start().0 .0;
 707            let mut block_end = self.transforms.end(&()).0 .0;
 708            self.transforms.next(&());
 709            if self.transforms.item().is_none() {
 710                block_end -= 1;
 711            }
 712
 713            let start_in_block = self.output_row - block_start;
 714            let end_in_block = cmp::min(self.max_output_row, block_end) - block_start;
 715            let line_count = end_in_block - start_in_block;
 716            self.output_row += line_count;
 717
 718            return Some(Chunk {
 719                text: unsafe { std::str::from_utf8_unchecked(&NEWLINES[..line_count as usize]) },
 720                highlight_style: None,
 721                diagnostic: None,
 722            });
 723        }
 724
 725        if self.input_chunk.text.is_empty() {
 726            if let Some(input_chunk) = self.input_chunks.next() {
 727                self.input_chunk = input_chunk;
 728            } else {
 729                self.output_row += 1;
 730                if self.output_row < self.max_output_row {
 731                    self.transforms.next(&());
 732                    return Some(Chunk {
 733                        text: "\n",
 734                        ..Default::default()
 735                    });
 736                } else {
 737                    return None;
 738                }
 739            }
 740        }
 741
 742        let transform_end = self.transforms.end(&()).0 .0;
 743        let (prefix_rows, prefix_bytes) =
 744            offset_for_row(self.input_chunk.text, transform_end - self.output_row);
 745        self.output_row += prefix_rows;
 746        let (prefix, suffix) = self.input_chunk.text.split_at(prefix_bytes);
 747        self.input_chunk.text = suffix;
 748        if self.output_row == transform_end {
 749            self.transforms.next(&());
 750        }
 751
 752        Some(Chunk {
 753            text: prefix,
 754            ..self.input_chunk
 755        })
 756    }
 757}
 758
 759impl<'a> Iterator for BufferRows<'a> {
 760    type Item = Option<u32>;
 761
 762    fn next(&mut self) -> Option<Self::Item> {
 763        if self.started {
 764            self.output_row += 1;
 765        } else {
 766            self.started = true;
 767        }
 768
 769        if self.output_row >= self.transforms.end(&()).0 .0 {
 770            self.transforms.next(&());
 771        }
 772
 773        let transform = self.transforms.item()?;
 774        if transform.block.is_some() {
 775            Some(None)
 776        } else {
 777            Some(self.input_buffer_rows.next().unwrap())
 778        }
 779    }
 780}
 781
 782impl sum_tree::Item for Transform {
 783    type Summary = TransformSummary;
 784
 785    fn summary(&self) -> Self::Summary {
 786        self.summary.clone()
 787    }
 788}
 789
 790impl sum_tree::Summary for TransformSummary {
 791    type Context = ();
 792
 793    fn add_summary(&mut self, summary: &Self, _: &()) {
 794        self.input_rows += summary.input_rows;
 795        self.output_rows += summary.output_rows;
 796    }
 797}
 798
 799impl<'a> sum_tree::Dimension<'a, TransformSummary> for WrapRow {
 800    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 801        self.0 += summary.input_rows;
 802    }
 803}
 804
 805impl<'a> sum_tree::Dimension<'a, TransformSummary> for BlockRow {
 806    fn add_summary(&mut self, summary: &'a TransformSummary, _: &()) {
 807        self.0 += summary.output_rows;
 808    }
 809}
 810
 811impl BlockDisposition {
 812    fn is_below(&self) -> bool {
 813        matches!(self, BlockDisposition::Below)
 814    }
 815}
 816
 817impl AlignedBlock {
 818    pub fn height(&self) -> u32 {
 819        self.height as u32
 820    }
 821
 822    pub fn column(&self) -> u32 {
 823        self.column
 824    }
 825
 826    pub fn render(&self, cx: &BlockContext) -> ElementBox {
 827        self.render.lock()(cx)
 828    }
 829
 830    pub fn disposition(&self) -> BlockDisposition {
 831        self.block.disposition
 832    }
 833}
 834
 835impl Deref for AlignedBlock {
 836    type Target = Block;
 837
 838    fn deref(&self) -> &Self::Target {
 839        self.block.as_ref()
 840    }
 841}
 842
 843impl Debug for Block {
 844    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 845        f.debug_struct("Block")
 846            .field("id", &self.id)
 847            .field("position", &self.position)
 848            .field("disposition", &self.disposition)
 849            .finish()
 850    }
 851}
 852
 853// Count the number of bytes prior to a target point. If the string doesn't contain the target
 854// point, return its total extent. Otherwise return the target point itself.
 855fn offset_for_row(s: &str, target: u32) -> (u32, usize) {
 856    let mut row = 0;
 857    let mut offset = 0;
 858    for (ix, line) in s.split('\n').enumerate() {
 859        if ix > 0 {
 860            row += 1;
 861            offset += 1;
 862        }
 863        if row >= target {
 864            break;
 865        }
 866        offset += line.len() as usize;
 867    }
 868    (row, offset)
 869}
 870
 871#[cfg(test)]
 872mod tests {
 873    use super::*;
 874    use crate::display_map::{fold_map::FoldMap, tab_map::TabMap, wrap_map::WrapMap};
 875    use gpui::{elements::Empty, Element};
 876    use language::Buffer;
 877    use rand::prelude::*;
 878    use std::env;
 879    use text::RandomCharIter;
 880
 881    #[gpui::test]
 882    fn test_offset_for_row() {
 883        assert_eq!(offset_for_row("", 0), (0, 0));
 884        assert_eq!(offset_for_row("", 1), (0, 0));
 885        assert_eq!(offset_for_row("abcd", 0), (0, 0));
 886        assert_eq!(offset_for_row("abcd", 1), (0, 4));
 887        assert_eq!(offset_for_row("\n", 0), (0, 0));
 888        assert_eq!(offset_for_row("\n", 1), (1, 1));
 889        assert_eq!(offset_for_row("abc\ndef\nghi", 0), (0, 0));
 890        assert_eq!(offset_for_row("abc\ndef\nghi", 1), (1, 4));
 891        assert_eq!(offset_for_row("abc\ndef\nghi", 2), (2, 8));
 892        assert_eq!(offset_for_row("abc\ndef\nghi", 3), (2, 11));
 893    }
 894
 895    #[gpui::test]
 896    fn test_basic_blocks(cx: &mut gpui::MutableAppContext) {
 897        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
 898        let font_id = cx
 899            .font_cache()
 900            .select_font(family_id, &Default::default())
 901            .unwrap();
 902
 903        let text = "aaa\nbbb\nccc\nddd";
 904
 905        let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
 906        let (fold_map, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot());
 907        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
 908        let (wrap_map, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, None, cx);
 909        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot.clone());
 910
 911        let mut writer = block_map.write(wraps_snapshot.clone(), vec![], cx);
 912        writer.insert(
 913            vec![
 914                BlockProperties {
 915                    position: Point::new(1, 0),
 916                    height: 1,
 917                    disposition: BlockDisposition::Above,
 918                    render: Arc::new(|_| Empty::new().named("block 1")),
 919                },
 920                BlockProperties {
 921                    position: Point::new(1, 2),
 922                    height: 2,
 923                    disposition: BlockDisposition::Above,
 924                    render: Arc::new(|_| Empty::new().named("block 2")),
 925                },
 926                BlockProperties {
 927                    position: Point::new(3, 3),
 928                    height: 3,
 929                    disposition: BlockDisposition::Below,
 930                    render: Arc::new(|_| Empty::new().named("block 3")),
 931                },
 932            ],
 933            cx,
 934        );
 935
 936        let mut snapshot = block_map.read(wraps_snapshot, vec![], cx);
 937        assert_eq!(snapshot.text(), "aaa\n\n\n\nbbb\nccc\nddd\n\n\n");
 938
 939        let blocks = snapshot
 940            .blocks_in_range(0..8)
 941            .map(|(start_row, block)| {
 942                (
 943                    start_row..start_row + block.height(),
 944                    block.column(),
 945                    block
 946                        .render(&BlockContext { cx, anchor_x: 0. })
 947                        .name()
 948                        .unwrap()
 949                        .to_string(),
 950                )
 951            })
 952            .collect::<Vec<_>>();
 953        assert_eq!(
 954            blocks,
 955            &[
 956                (1..2, 0, "block 1".to_string()),
 957                (2..4, 2, "block 2".to_string()),
 958                (7..10, 3, "block 3".to_string()),
 959            ]
 960        );
 961
 962        assert_eq!(
 963            snapshot.to_block_point(WrapPoint::new(0, 3)),
 964            BlockPoint::new(0, 3)
 965        );
 966        assert_eq!(
 967            snapshot.to_block_point(WrapPoint::new(1, 0)),
 968            BlockPoint::new(4, 0)
 969        );
 970        assert_eq!(
 971            snapshot.to_block_point(WrapPoint::new(3, 3)),
 972            BlockPoint::new(6, 3)
 973        );
 974
 975        assert_eq!(
 976            snapshot.to_wrap_point(BlockPoint::new(0, 3)),
 977            WrapPoint::new(0, 3)
 978        );
 979        assert_eq!(
 980            snapshot.to_wrap_point(BlockPoint::new(1, 0)),
 981            WrapPoint::new(1, 0)
 982        );
 983        assert_eq!(
 984            snapshot.to_wrap_point(BlockPoint::new(3, 0)),
 985            WrapPoint::new(1, 0)
 986        );
 987        assert_eq!(
 988            snapshot.to_wrap_point(BlockPoint::new(7, 0)),
 989            WrapPoint::new(3, 3)
 990        );
 991
 992        assert_eq!(
 993            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Left),
 994            BlockPoint::new(0, 3)
 995        );
 996        assert_eq!(
 997            snapshot.clip_point(BlockPoint::new(1, 0), Bias::Right),
 998            BlockPoint::new(4, 0)
 999        );
1000        assert_eq!(
1001            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Left),
1002            BlockPoint::new(0, 3)
1003        );
1004        assert_eq!(
1005            snapshot.clip_point(BlockPoint::new(1, 1), Bias::Right),
1006            BlockPoint::new(4, 0)
1007        );
1008        assert_eq!(
1009            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Left),
1010            BlockPoint::new(4, 0)
1011        );
1012        assert_eq!(
1013            snapshot.clip_point(BlockPoint::new(4, 0), Bias::Right),
1014            BlockPoint::new(4, 0)
1015        );
1016        assert_eq!(
1017            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Left),
1018            BlockPoint::new(6, 3)
1019        );
1020        assert_eq!(
1021            snapshot.clip_point(BlockPoint::new(6, 3), Bias::Right),
1022            BlockPoint::new(6, 3)
1023        );
1024        assert_eq!(
1025            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Left),
1026            BlockPoint::new(6, 3)
1027        );
1028        assert_eq!(
1029            snapshot.clip_point(BlockPoint::new(7, 0), Bias::Right),
1030            BlockPoint::new(6, 3)
1031        );
1032
1033        assert_eq!(
1034            snapshot.buffer_rows(0).collect::<Vec<_>>(),
1035            &[
1036                Some(0),
1037                None,
1038                None,
1039                None,
1040                Some(1),
1041                Some(2),
1042                Some(3),
1043                None,
1044                None,
1045                None
1046            ]
1047        );
1048
1049        // Insert a line break, separating two block decorations into separate
1050        // lines.
1051        let (buffer_snapshot, buffer_edits) = buffer.update(cx, |buffer, cx| {
1052            let v0 = buffer.version();
1053            buffer.edit([Point::new(1, 1)..Point::new(1, 1)], "!!!\n", cx);
1054            (buffer.snapshot(), buffer.edits_since(&v0).collect())
1055        });
1056
1057        let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot, buffer_edits);
1058        let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1059        let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1060            wrap_map.sync(tabs_snapshot, tab_edits, cx)
1061        });
1062        let mut snapshot = block_map.read(wraps_snapshot, wrap_edits, cx);
1063        assert_eq!(snapshot.text(), "aaa\n\nb!!!\n\n\nbb\nccc\nddd\n\n\n");
1064    }
1065
1066    #[gpui::test]
1067    fn test_blocks_on_wrapped_lines(cx: &mut gpui::MutableAppContext) {
1068        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1069        let font_id = cx
1070            .font_cache()
1071            .select_font(family_id, &Default::default())
1072            .unwrap();
1073
1074        let text = "one two three\nfour five six\nseven eight";
1075
1076        let buffer = cx.add_model(|cx| Buffer::new(0, text, cx));
1077        let (_, folds_snapshot) = FoldMap::new(buffer.read(cx).snapshot());
1078        let (_, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), 1);
1079        let (_, wraps_snapshot) = WrapMap::new(tabs_snapshot, font_id, 14.0, Some(60.), cx);
1080        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot.clone());
1081
1082        let mut writer = block_map.write(wraps_snapshot.clone(), vec![], cx);
1083        writer.insert(
1084            vec![
1085                BlockProperties {
1086                    position: Point::new(1, 12),
1087                    disposition: BlockDisposition::Above,
1088                    render: Arc::new(|_| Empty::new().named("block 1")),
1089                    height: 1,
1090                },
1091                BlockProperties {
1092                    position: Point::new(1, 1),
1093                    disposition: BlockDisposition::Below,
1094                    render: Arc::new(|_| Empty::new().named("block 2")),
1095                    height: 1,
1096                },
1097            ],
1098            cx,
1099        );
1100
1101        // Blocks with an 'above' disposition go above their corresponding buffer line.
1102        // Blocks with a 'below' disposition go below their corresponding buffer line.
1103        let mut snapshot = block_map.read(wraps_snapshot, vec![], cx);
1104        assert_eq!(
1105            snapshot.text(),
1106            "one two \nthree\n\nfour five \nsix\n\nseven \neight"
1107        );
1108    }
1109
1110    #[gpui::test(iterations = 100)]
1111    fn test_random_blocks(cx: &mut gpui::MutableAppContext, mut rng: StdRng) {
1112        let operations = env::var("OPERATIONS")
1113            .map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
1114            .unwrap_or(10);
1115
1116        let wrap_width = if rng.gen_bool(0.2) {
1117            None
1118        } else {
1119            Some(rng.gen_range(0.0..=100.0))
1120        };
1121        let tab_size = 1;
1122        let family_id = cx.font_cache().load_family(&["Helvetica"]).unwrap();
1123        let font_id = cx
1124            .font_cache()
1125            .select_font(family_id, &Default::default())
1126            .unwrap();
1127        let font_size = 14.0;
1128
1129        log::info!("Wrap width: {:?}", wrap_width);
1130
1131        let buffer = cx.add_model(|cx| {
1132            let len = rng.gen_range(0..10);
1133            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
1134            log::info!("initial buffer text: {:?}", text);
1135            Buffer::new(0, text, cx)
1136        });
1137        let mut buffer_snapshot = buffer.read(cx).snapshot();
1138        let (fold_map, folds_snapshot) = FoldMap::new(buffer_snapshot.clone());
1139        let (tab_map, tabs_snapshot) = TabMap::new(folds_snapshot.clone(), tab_size);
1140        let (wrap_map, wraps_snapshot) =
1141            WrapMap::new(tabs_snapshot, font_id, font_size, wrap_width, cx);
1142        let mut block_map = BlockMap::new(buffer.clone(), wraps_snapshot);
1143        let mut expected_blocks = Vec::new();
1144
1145        for _ in 0..operations {
1146            let mut buffer_edits = Vec::new();
1147            match rng.gen_range(0..=100) {
1148                0..=19 => {
1149                    let wrap_width = if rng.gen_bool(0.2) {
1150                        None
1151                    } else {
1152                        Some(rng.gen_range(0.0..=100.0))
1153                    };
1154                    log::info!("Setting wrap width to {:?}", wrap_width);
1155                    wrap_map.update(cx, |map, cx| map.set_wrap_width(wrap_width, cx));
1156                }
1157                20..=39 => {
1158                    let block_count = rng.gen_range(1..=1);
1159                    let block_properties = (0..block_count)
1160                        .map(|_| {
1161                            let buffer = buffer.read(cx);
1162                            let position = buffer.anchor_after(
1163                                buffer.clip_offset(rng.gen_range(0..=buffer.len()), Bias::Left),
1164                            );
1165
1166                            let disposition = if rng.gen() {
1167                                BlockDisposition::Above
1168                            } else {
1169                                BlockDisposition::Below
1170                            };
1171                            let height = rng.gen_range(1..5);
1172                            log::info!(
1173                                "inserting block {:?} {:?} with height {}",
1174                                disposition,
1175                                position.to_point(buffer),
1176                                height
1177                            );
1178                            BlockProperties {
1179                                position,
1180                                height,
1181                                disposition,
1182                                render: Arc::new(|_| Empty::new().boxed()),
1183                            }
1184                        })
1185                        .collect::<Vec<_>>();
1186
1187                    let (folds_snapshot, fold_edits) =
1188                        fold_map.read(buffer_snapshot.clone(), vec![]);
1189                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1190                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1191                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1192                    });
1193                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits, cx);
1194                    let block_ids = block_map.insert(block_properties.clone(), cx);
1195                    for (block_id, props) in block_ids.into_iter().zip(block_properties) {
1196                        expected_blocks.push((block_id, props));
1197                    }
1198                }
1199                40..=59 if !expected_blocks.is_empty() => {
1200                    let block_count = rng.gen_range(1..=4.min(expected_blocks.len()));
1201                    let block_ids_to_remove = (0..block_count)
1202                        .map(|_| {
1203                            expected_blocks
1204                                .remove(rng.gen_range(0..expected_blocks.len()))
1205                                .0
1206                        })
1207                        .collect();
1208
1209                    let (folds_snapshot, fold_edits) =
1210                        fold_map.read(buffer_snapshot.clone(), vec![]);
1211                    let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1212                    let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1213                        wrap_map.sync(tabs_snapshot, tab_edits, cx)
1214                    });
1215                    let mut block_map = block_map.write(wraps_snapshot, wrap_edits, cx);
1216                    block_map.remove(block_ids_to_remove, cx);
1217                }
1218                _ => {
1219                    buffer.update(cx, |buffer, cx| {
1220                        let v0 = buffer.version();
1221                        let edit_count = rng.gen_range(1..=5);
1222                        buffer.randomly_edit(&mut rng, edit_count, cx);
1223                        log::info!("buffer text: {:?}", buffer.text());
1224                        buffer_edits.extend(buffer.edits_since(&v0));
1225                        buffer_snapshot = buffer.snapshot();
1226                    });
1227                }
1228            }
1229
1230            let (folds_snapshot, fold_edits) = fold_map.read(buffer_snapshot.clone(), buffer_edits);
1231            let (tabs_snapshot, tab_edits) = tab_map.sync(folds_snapshot, fold_edits);
1232            let (wraps_snapshot, wrap_edits) = wrap_map.update(cx, |wrap_map, cx| {
1233                wrap_map.sync(tabs_snapshot, tab_edits, cx)
1234            });
1235            let mut blocks_snapshot = block_map.read(wraps_snapshot.clone(), wrap_edits, cx);
1236            assert_eq!(
1237                blocks_snapshot.transforms.summary().input_rows,
1238                wraps_snapshot.max_point().row() + 1
1239            );
1240            log::info!("blocks text: {:?}", blocks_snapshot.text());
1241
1242            let buffer = buffer.read(cx);
1243            let mut sorted_blocks = expected_blocks
1244                .iter()
1245                .cloned()
1246                .map(|(id, block)| {
1247                    let mut position = block.position.to_point(buffer);
1248                    let column = wraps_snapshot.from_point(position, Bias::Left).column();
1249                    match block.disposition {
1250                        BlockDisposition::Above => {
1251                            position.column = 0;
1252                        }
1253                        BlockDisposition::Below => {
1254                            position.column = buffer.line_len(position.row);
1255                        }
1256                    };
1257                    let row = wraps_snapshot.from_point(position, Bias::Left).row();
1258                    (
1259                        id,
1260                        BlockProperties {
1261                            position: BlockPoint::new(row, column),
1262                            height: block.height,
1263                            disposition: block.disposition,
1264                            render: block.render.clone(),
1265                        },
1266                    )
1267                })
1268                .collect::<Vec<_>>();
1269            sorted_blocks
1270                .sort_unstable_by_key(|(id, block)| (block.position.row, block.disposition, *id));
1271            let mut sorted_blocks = sorted_blocks.into_iter().peekable();
1272
1273            let mut expected_buffer_rows = Vec::new();
1274            let mut expected_text = String::new();
1275            let input_text = wraps_snapshot.text();
1276            for (row, input_line) in input_text.split('\n').enumerate() {
1277                let row = row as u32;
1278                if row > 0 {
1279                    expected_text.push('\n');
1280                }
1281
1282                let buffer_row = wraps_snapshot
1283                    .to_point(WrapPoint::new(row, 0), Bias::Left)
1284                    .row;
1285
1286                while let Some((_, block)) = sorted_blocks.peek() {
1287                    if block.position.row == row && block.disposition == BlockDisposition::Above {
1288                        let text = "\n".repeat(block.height as usize);
1289                        expected_text.push_str(&text);
1290                        for _ in 0..block.height {
1291                            expected_buffer_rows.push(None);
1292                        }
1293                        sorted_blocks.next();
1294                    } else {
1295                        break;
1296                    }
1297                }
1298
1299                let soft_wrapped = wraps_snapshot.to_tab_point(WrapPoint::new(row, 0)).column() > 0;
1300                expected_buffer_rows.push(if soft_wrapped { None } else { Some(buffer_row) });
1301                expected_text.push_str(input_line);
1302
1303                while let Some((_, block)) = sorted_blocks.peek() {
1304                    if block.position.row == row && block.disposition == BlockDisposition::Below {
1305                        let text = "\n".repeat(block.height as usize);
1306                        expected_text.push_str(&text);
1307                        for _ in 0..block.height {
1308                            expected_buffer_rows.push(None);
1309                        }
1310                        sorted_blocks.next();
1311                    } else {
1312                        break;
1313                    }
1314                }
1315            }
1316
1317            let expected_lines = expected_text.split('\n').collect::<Vec<_>>();
1318            let expected_row_count = expected_lines.len();
1319            for start_row in 0..expected_row_count {
1320                let expected_text = expected_lines[start_row..].join("\n");
1321                let actual_text = blocks_snapshot
1322                    .chunks(start_row as u32..expected_row_count as u32, None)
1323                    .map(|chunk| chunk.text)
1324                    .collect::<String>();
1325                assert_eq!(
1326                    actual_text, expected_text,
1327                    "incorrect text starting from row {}",
1328                    start_row
1329                );
1330                assert_eq!(
1331                    blocks_snapshot
1332                        .buffer_rows(start_row as u32)
1333                        .collect::<Vec<_>>(),
1334                    &expected_buffer_rows[start_row..]
1335                );
1336            }
1337
1338            let mut expected_longest_rows = Vec::new();
1339            let mut longest_line_len = -1_isize;
1340            for (row, line) in expected_lines.iter().enumerate() {
1341                let row = row as u32;
1342
1343                assert_eq!(
1344                    blocks_snapshot.line_len(row),
1345                    line.len() as u32,
1346                    "invalid line len for row {}",
1347                    row
1348                );
1349
1350                let line_char_count = line.chars().count() as isize;
1351                match line_char_count.cmp(&longest_line_len) {
1352                    Ordering::Less => {}
1353                    Ordering::Equal => expected_longest_rows.push(row),
1354                    Ordering::Greater => {
1355                        longest_line_len = line_char_count;
1356                        expected_longest_rows.clear();
1357                        expected_longest_rows.push(row);
1358                    }
1359                }
1360            }
1361
1362            let longest_row = blocks_snapshot.longest_row();
1363            assert!(
1364                expected_longest_rows.contains(&longest_row),
1365                "incorrect longest row {}. expected {:?} with length {}",
1366                longest_row,
1367                expected_longest_rows,
1368                longest_line_len,
1369            );
1370
1371            for row in 0..=blocks_snapshot.wrap_snapshot.max_point().row() {
1372                let wrap_point = WrapPoint::new(row, 0);
1373                let block_point = blocks_snapshot.to_block_point(wrap_point);
1374                assert_eq!(blocks_snapshot.to_wrap_point(block_point), wrap_point);
1375            }
1376
1377            let mut block_point = BlockPoint::new(0, 0);
1378            for c in expected_text.chars() {
1379                let left_point = blocks_snapshot.clip_point(block_point, Bias::Left);
1380                let right_point = blocks_snapshot.clip_point(block_point, Bias::Right);
1381
1382                assert_eq!(
1383                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(left_point)),
1384                    left_point
1385                );
1386                assert_eq!(
1387                    blocks_snapshot.to_block_point(blocks_snapshot.to_wrap_point(right_point)),
1388                    right_point
1389                );
1390
1391                if c == '\n' {
1392                    block_point.0 += Point::new(1, 0);
1393                } else {
1394                    block_point.column += c.len_utf8() as u32;
1395                }
1396            }
1397        }
1398    }
1399}