hunk_diff.rs

  1use std::ops::Range;
  2
  3use collections::{hash_map, HashMap, HashSet};
  4use git::diff::{DiffHunk, DiffHunkStatus};
  5use gpui::{AppContext, Hsla, Model, Task, View};
  6use language::Buffer;
  7use multi_buffer::{Anchor, ExcerptRange, MultiBuffer, MultiBufferSnapshot, ToPoint};
  8use text::{BufferId, Point};
  9use ui::{
 10    div, ActiveTheme, Context as _, IntoElement, ParentElement, Styled, ViewContext, VisualContext,
 11};
 12use util::{debug_panic, RangeExt};
 13
 14use crate::{
 15    git::{diff_hunk_to_display, DisplayDiffHunk},
 16    hunks_for_selections, BlockDisposition, BlockId, BlockProperties, BlockStyle, DiffRowHighlight,
 17    Editor, ExpandAllHunkDiffs, RangeToAnchorExt, ToDisplayPoint, ToggleHunkDiff,
 18};
 19
 20#[derive(Debug, Clone)]
 21pub(super) struct HunkToExpand {
 22    pub multi_buffer_range: Range<Anchor>,
 23    pub status: DiffHunkStatus,
 24    pub diff_base_byte_range: Range<usize>,
 25}
 26
 27#[derive(Debug, Default)]
 28pub(super) struct ExpandedHunks {
 29    hunks: Vec<ExpandedHunk>,
 30    diff_base: HashMap<BufferId, DiffBaseBuffer>,
 31    hunk_update_tasks: HashMap<Option<BufferId>, Task<()>>,
 32}
 33
 34#[derive(Debug)]
 35struct DiffBaseBuffer {
 36    buffer: Model<Buffer>,
 37    diff_base_version: usize,
 38}
 39
 40impl ExpandedHunks {
 41    pub fn hunks(&self, include_folded: bool) -> impl Iterator<Item = &ExpandedHunk> {
 42        self.hunks
 43            .iter()
 44            .filter(move |hunk| include_folded || !hunk.folded)
 45    }
 46}
 47
 48#[derive(Debug, Clone)]
 49pub(super) struct ExpandedHunk {
 50    pub block: Option<BlockId>,
 51    pub hunk_range: Range<Anchor>,
 52    pub diff_base_byte_range: Range<usize>,
 53    pub status: DiffHunkStatus,
 54    pub folded: bool,
 55}
 56
 57impl Editor {
 58    pub fn toggle_hunk_diff(&mut self, _: &ToggleHunkDiff, cx: &mut ViewContext<Self>) {
 59        let multi_buffer_snapshot = self.buffer().read(cx).snapshot(cx);
 60        let selections = self.selections.disjoint_anchors();
 61        self.toggle_hunks_expanded(
 62            hunks_for_selections(&multi_buffer_snapshot, &selections),
 63            cx,
 64        );
 65    }
 66
 67    pub fn expand_all_hunk_diffs(&mut self, _: &ExpandAllHunkDiffs, cx: &mut ViewContext<Self>) {
 68        let snapshot = self.snapshot(cx);
 69        let display_rows_with_expanded_hunks = self
 70            .expanded_hunks
 71            .hunks(false)
 72            .map(|hunk| &hunk.hunk_range)
 73            .map(|anchor_range| {
 74                (
 75                    anchor_range
 76                        .start
 77                        .to_display_point(&snapshot.display_snapshot)
 78                        .row(),
 79                    anchor_range
 80                        .end
 81                        .to_display_point(&snapshot.display_snapshot)
 82                        .row(),
 83                )
 84            })
 85            .collect::<HashMap<_, _>>();
 86        let hunks = snapshot
 87            .display_snapshot
 88            .buffer_snapshot
 89            .git_diff_hunks_in_range(0..u32::MAX)
 90            .filter(|hunk| {
 91                let hunk_display_row_range = Point::new(hunk.associated_range.start, 0)
 92                    .to_display_point(&snapshot.display_snapshot)
 93                    ..Point::new(hunk.associated_range.end, 0)
 94                        .to_display_point(&snapshot.display_snapshot);
 95                let row_range_end =
 96                    display_rows_with_expanded_hunks.get(&hunk_display_row_range.start.row());
 97                row_range_end.is_none() || row_range_end != Some(&hunk_display_row_range.end.row())
 98            });
 99        self.toggle_hunks_expanded(hunks.collect(), cx);
100    }
101
102    fn toggle_hunks_expanded(
103        &mut self,
104        hunks_to_toggle: Vec<DiffHunk<u32>>,
105        cx: &mut ViewContext<Self>,
106    ) {
107        let previous_toggle_task = self.expanded_hunks.hunk_update_tasks.remove(&None);
108        let new_toggle_task = cx.spawn(move |editor, mut cx| async move {
109            if let Some(task) = previous_toggle_task {
110                task.await;
111            }
112
113            editor
114                .update(&mut cx, |editor, cx| {
115                    let snapshot = editor.snapshot(cx);
116                    let mut hunks_to_toggle = hunks_to_toggle.into_iter().fuse().peekable();
117                    let mut highlights_to_remove =
118                        Vec::with_capacity(editor.expanded_hunks.hunks.len());
119                    let mut blocks_to_remove = HashSet::default();
120                    let mut hunks_to_expand = Vec::new();
121                    editor.expanded_hunks.hunks.retain(|expanded_hunk| {
122                        if expanded_hunk.folded {
123                            return true;
124                        }
125                        let expanded_hunk_row_range = expanded_hunk
126                            .hunk_range
127                            .start
128                            .to_display_point(&snapshot)
129                            .row()
130                            ..expanded_hunk
131                                .hunk_range
132                                .end
133                                .to_display_point(&snapshot)
134                                .row();
135                        let mut retain = true;
136                        while let Some(hunk_to_toggle) = hunks_to_toggle.peek() {
137                            match diff_hunk_to_display(hunk_to_toggle, &snapshot) {
138                                DisplayDiffHunk::Folded { .. } => {
139                                    hunks_to_toggle.next();
140                                    continue;
141                                }
142                                DisplayDiffHunk::Unfolded {
143                                    diff_base_byte_range,
144                                    display_row_range,
145                                    multi_buffer_range,
146                                    status,
147                                } => {
148                                    let hunk_to_toggle_row_range = display_row_range;
149                                    if hunk_to_toggle_row_range.start > expanded_hunk_row_range.end
150                                    {
151                                        break;
152                                    } else if expanded_hunk_row_range == hunk_to_toggle_row_range {
153                                        highlights_to_remove.push(expanded_hunk.hunk_range.clone());
154                                        blocks_to_remove.extend(expanded_hunk.block);
155                                        hunks_to_toggle.next();
156                                        retain = false;
157                                        break;
158                                    } else {
159                                        hunks_to_expand.push(HunkToExpand {
160                                            status,
161                                            multi_buffer_range,
162                                            diff_base_byte_range,
163                                        });
164                                        hunks_to_toggle.next();
165                                        continue;
166                                    }
167                                }
168                            }
169                        }
170
171                        retain
172                    });
173                    for remaining_hunk in hunks_to_toggle {
174                        let remaining_hunk_point_range =
175                            Point::new(remaining_hunk.associated_range.start, 0)
176                                ..Point::new(remaining_hunk.associated_range.end, 0);
177                        hunks_to_expand.push(HunkToExpand {
178                            status: remaining_hunk.status(),
179                            multi_buffer_range: remaining_hunk_point_range
180                                .to_anchors(&snapshot.buffer_snapshot),
181                            diff_base_byte_range: remaining_hunk.diff_base_byte_range.clone(),
182                        });
183                    }
184
185                    for removed_rows in highlights_to_remove {
186                        editor.highlight_rows::<DiffRowHighlight>(removed_rows, None, cx);
187                    }
188                    editor.remove_blocks(blocks_to_remove, None, cx);
189                    for hunk in hunks_to_expand {
190                        editor.expand_diff_hunk(None, &hunk, cx);
191                    }
192                    cx.notify();
193                })
194                .ok();
195        });
196
197        self.expanded_hunks
198            .hunk_update_tasks
199            .insert(None, cx.background_executor().spawn(new_toggle_task));
200    }
201
202    pub(super) fn expand_diff_hunk(
203        &mut self,
204        diff_base_buffer: Option<Model<Buffer>>,
205        hunk: &HunkToExpand,
206        cx: &mut ViewContext<'_, Editor>,
207    ) -> Option<()> {
208        let multi_buffer_snapshot = self.buffer().read(cx).snapshot(cx);
209        let multi_buffer_row_range = hunk
210            .multi_buffer_range
211            .start
212            .to_point(&multi_buffer_snapshot)
213            ..hunk.multi_buffer_range.end.to_point(&multi_buffer_snapshot);
214        let hunk_start = hunk.multi_buffer_range.start;
215        let hunk_end = hunk.multi_buffer_range.end;
216
217        let buffer = self.buffer().clone();
218        let (diff_base_buffer, deleted_text_range, deleted_text_lines) =
219            buffer.update(cx, |buffer, cx| {
220                let snapshot = buffer.snapshot(cx);
221                let hunk = buffer_diff_hunk(&snapshot, multi_buffer_row_range.clone())?;
222                let mut buffer_ranges = buffer.range_to_buffer_ranges(multi_buffer_row_range, cx);
223                if buffer_ranges.len() == 1 {
224                    let (buffer, _, _) = buffer_ranges.pop()?;
225                    let diff_base_buffer = diff_base_buffer
226                        .or_else(|| self.current_diff_base_buffer(&buffer, cx))
227                        .or_else(|| create_diff_base_buffer(&buffer, cx));
228                    let buffer = buffer.read(cx);
229                    let deleted_text_lines = buffer.diff_base().map(|diff_base| {
230                        let diff_start_row = diff_base
231                            .offset_to_point(hunk.diff_base_byte_range.start)
232                            .row;
233                        let diff_end_row =
234                            diff_base.offset_to_point(hunk.diff_base_byte_range.end).row;
235                        let line_count = diff_end_row - diff_start_row;
236                        line_count as usize
237                    });
238                    Some((
239                        diff_base_buffer?,
240                        hunk.diff_base_byte_range,
241                        deleted_text_lines,
242                    ))
243                } else {
244                    None
245                }
246            })?;
247
248        let block_insert_index = match self.expanded_hunks.hunks.binary_search_by(|probe| {
249            probe
250                .hunk_range
251                .start
252                .cmp(&hunk_start, &multi_buffer_snapshot)
253        }) {
254            Ok(_already_present) => return None,
255            Err(ix) => ix,
256        };
257
258        let block = match hunk.status {
259            DiffHunkStatus::Removed => self.add_deleted_lines(
260                deleted_text_lines,
261                hunk_start,
262                diff_base_buffer,
263                deleted_text_range,
264                cx,
265            ),
266            DiffHunkStatus::Added => {
267                self.highlight_rows::<DiffRowHighlight>(
268                    hunk_start..hunk_end,
269                    Some(added_hunk_color(cx)),
270                    cx,
271                );
272                None
273            }
274            DiffHunkStatus::Modified => {
275                self.highlight_rows::<DiffRowHighlight>(
276                    hunk_start..hunk_end,
277                    Some(added_hunk_color(cx)),
278                    cx,
279                );
280                self.add_deleted_lines(
281                    deleted_text_lines,
282                    hunk_start,
283                    diff_base_buffer,
284                    deleted_text_range,
285                    cx,
286                )
287            }
288        };
289        self.expanded_hunks.hunks.insert(
290            block_insert_index,
291            ExpandedHunk {
292                block,
293                hunk_range: hunk_start..hunk_end,
294                status: hunk.status,
295                folded: false,
296                diff_base_byte_range: hunk.diff_base_byte_range.clone(),
297            },
298        );
299
300        Some(())
301    }
302
303    fn add_deleted_lines(
304        &mut self,
305        deleted_text_lines: Option<usize>,
306        hunk_start: Anchor,
307        diff_base_buffer: Model<Buffer>,
308        deleted_text_range: Range<usize>,
309        cx: &mut ViewContext<'_, Self>,
310    ) -> Option<BlockId> {
311        if let Some(deleted_text_lines) = deleted_text_lines {
312            self.insert_deleted_text_block(
313                hunk_start,
314                diff_base_buffer,
315                deleted_text_range,
316                deleted_text_lines as u8,
317                cx,
318            )
319        } else {
320            debug_panic!("Found no deleted text for removed hunk on position {hunk_start:?}");
321            None
322        }
323    }
324
325    fn insert_deleted_text_block(
326        &mut self,
327        position: Anchor,
328        diff_base_buffer: Model<Buffer>,
329        deleted_text_range: Range<usize>,
330        deleted_text_height: u8,
331        cx: &mut ViewContext<'_, Self>,
332    ) -> Option<BlockId> {
333        let deleted_hunk_color = deleted_hunk_color(cx);
334        let (editor_height, editor_with_deleted_text) =
335            editor_with_deleted_text(diff_base_buffer, deleted_text_range, deleted_hunk_color, cx);
336        let parent_gutter_offset = self.gutter_dimensions.width + self.gutter_dimensions.margin;
337        let mut new_block_ids = self.insert_blocks(
338            Some(BlockProperties {
339                position,
340                height: editor_height.max(deleted_text_height),
341                style: BlockStyle::Flex,
342                render: Box::new(move |_| {
343                    div()
344                        .bg(deleted_hunk_color)
345                        .size_full()
346                        .pl(parent_gutter_offset)
347                        .child(editor_with_deleted_text.clone())
348                        .into_any_element()
349                }),
350                disposition: BlockDisposition::Above,
351            }),
352            None,
353            cx,
354        );
355        if new_block_ids.len() == 1 {
356            new_block_ids.pop()
357        } else {
358            debug_panic!(
359                "Inserted one editor block but did not receive exactly one block id: {new_block_ids:?}"
360            );
361            None
362        }
363    }
364
365    pub(super) fn clear_expanded_diff_hunks(&mut self, cx: &mut ViewContext<'_, Editor>) {
366        self.expanded_hunks.hunk_update_tasks.clear();
367        let to_remove = self
368            .expanded_hunks
369            .hunks
370            .drain(..)
371            .filter_map(|expanded_hunk| expanded_hunk.block)
372            .collect();
373        self.clear_row_highlights::<DiffRowHighlight>();
374        self.remove_blocks(to_remove, None, cx);
375    }
376
377    pub(super) fn sync_expanded_diff_hunks(
378        &mut self,
379        buffer: Model<Buffer>,
380        cx: &mut ViewContext<'_, Self>,
381    ) {
382        let buffer_id = buffer.read(cx).remote_id();
383        let buffer_diff_base_version = buffer.read(cx).diff_base_version();
384        self.expanded_hunks
385            .hunk_update_tasks
386            .remove(&Some(buffer_id));
387        let diff_base_buffer = self.current_diff_base_buffer(&buffer, cx);
388        let new_sync_task = cx.spawn(move |editor, mut cx| async move {
389            let diff_base_buffer_unchanged = diff_base_buffer.is_some();
390            let Ok(diff_base_buffer) =
391                cx.update(|cx| diff_base_buffer.or_else(|| create_diff_base_buffer(&buffer, cx)))
392            else {
393                return;
394            };
395            editor
396                .update(&mut cx, |editor, cx| {
397                    if let Some(diff_base_buffer) = &diff_base_buffer {
398                        editor.expanded_hunks.diff_base.insert(
399                            buffer_id,
400                            DiffBaseBuffer {
401                                buffer: diff_base_buffer.clone(),
402                                diff_base_version: buffer_diff_base_version,
403                            },
404                        );
405                    }
406
407                    let snapshot = editor.snapshot(cx);
408                    let buffer_snapshot = buffer.read(cx).snapshot();
409                    let mut recalculated_hunks = buffer_snapshot
410                        .git_diff_hunks_in_row_range(0..u32::MAX)
411                        .fuse()
412                        .peekable();
413                    let mut highlights_to_remove =
414                        Vec::with_capacity(editor.expanded_hunks.hunks.len());
415                    let mut blocks_to_remove = HashSet::default();
416                    let mut hunks_to_reexpand =
417                        Vec::with_capacity(editor.expanded_hunks.hunks.len());
418                    editor.expanded_hunks.hunks.retain_mut(|expanded_hunk| {
419                        if expanded_hunk.hunk_range.start.buffer_id != Some(buffer_id) {
420                            return true;
421                        };
422
423                        let mut retain = false;
424                        if diff_base_buffer_unchanged {
425                            let expanded_hunk_display_range = expanded_hunk
426                                .hunk_range
427                                .start
428                                .to_display_point(&snapshot)
429                                .row()
430                                ..expanded_hunk
431                                    .hunk_range
432                                    .end
433                                    .to_display_point(&snapshot)
434                                    .row();
435                            while let Some(buffer_hunk) = recalculated_hunks.peek() {
436                                match diff_hunk_to_display(buffer_hunk, &snapshot) {
437                                    DisplayDiffHunk::Folded { display_row } => {
438                                        recalculated_hunks.next();
439                                        if !expanded_hunk.folded
440                                            && expanded_hunk_display_range
441                                                .to_inclusive()
442                                                .contains(&display_row)
443                                        {
444                                            retain = true;
445                                            expanded_hunk.folded = true;
446                                            highlights_to_remove
447                                                .push(expanded_hunk.hunk_range.clone());
448                                            if let Some(block) = expanded_hunk.block.take() {
449                                                blocks_to_remove.insert(block);
450                                            }
451                                            break;
452                                        } else {
453                                            continue;
454                                        }
455                                    }
456                                    DisplayDiffHunk::Unfolded {
457                                        diff_base_byte_range,
458                                        display_row_range,
459                                        multi_buffer_range,
460                                        status,
461                                    } => {
462                                        let hunk_display_range = display_row_range;
463                                        if expanded_hunk_display_range.start
464                                            > hunk_display_range.end
465                                        {
466                                            recalculated_hunks.next();
467                                            continue;
468                                        } else if expanded_hunk_display_range.end
469                                            < hunk_display_range.start
470                                        {
471                                            break;
472                                        } else {
473                                            if !expanded_hunk.folded
474                                                && expanded_hunk_display_range == hunk_display_range
475                                                && expanded_hunk.status == buffer_hunk.status()
476                                                && expanded_hunk.diff_base_byte_range
477                                                    == buffer_hunk.diff_base_byte_range
478                                            {
479                                                recalculated_hunks.next();
480                                                retain = true;
481                                            } else {
482                                                hunks_to_reexpand.push(HunkToExpand {
483                                                    status,
484                                                    multi_buffer_range,
485                                                    diff_base_byte_range,
486                                                });
487                                            }
488                                            break;
489                                        }
490                                    }
491                                }
492                            }
493                        }
494                        if !retain {
495                            blocks_to_remove.extend(expanded_hunk.block);
496                            highlights_to_remove.push(expanded_hunk.hunk_range.clone());
497                        }
498                        retain
499                    });
500
501                    for removed_rows in highlights_to_remove {
502                        editor.highlight_rows::<DiffRowHighlight>(removed_rows, None, cx);
503                    }
504                    editor.remove_blocks(blocks_to_remove, None, cx);
505
506                    if let Some(diff_base_buffer) = &diff_base_buffer {
507                        for hunk in hunks_to_reexpand {
508                            editor.expand_diff_hunk(Some(diff_base_buffer.clone()), &hunk, cx);
509                        }
510                    }
511                })
512                .ok();
513        });
514
515        self.expanded_hunks.hunk_update_tasks.insert(
516            Some(buffer_id),
517            cx.background_executor().spawn(new_sync_task),
518        );
519    }
520
521    fn current_diff_base_buffer(
522        &mut self,
523        buffer: &Model<Buffer>,
524        cx: &mut AppContext,
525    ) -> Option<Model<Buffer>> {
526        buffer.update(cx, |buffer, _| {
527            match self.expanded_hunks.diff_base.entry(buffer.remote_id()) {
528                hash_map::Entry::Occupied(o) => {
529                    if o.get().diff_base_version != buffer.diff_base_version() {
530                        o.remove();
531                        None
532                    } else {
533                        Some(o.get().buffer.clone())
534                    }
535                }
536                hash_map::Entry::Vacant(_) => None,
537            }
538        })
539    }
540}
541
542fn create_diff_base_buffer(buffer: &Model<Buffer>, cx: &mut AppContext) -> Option<Model<Buffer>> {
543    buffer
544        .update(cx, |buffer, _| {
545            let language = buffer.language().cloned();
546            let diff_base = buffer.diff_base()?.clone();
547            Some((buffer.line_ending(), diff_base, language))
548        })
549        .map(|(line_ending, diff_base, language)| {
550            cx.new_model(|cx| {
551                let buffer = Buffer::local_normalized(diff_base, line_ending, cx);
552                match language {
553                    Some(language) => buffer.with_language(language, cx),
554                    None => buffer,
555                }
556            })
557        })
558}
559
560fn added_hunk_color(cx: &AppContext) -> Hsla {
561    let mut created_color = cx.theme().status().git().created;
562    created_color.fade_out(0.7);
563    created_color
564}
565
566fn deleted_hunk_color(cx: &AppContext) -> Hsla {
567    let mut deleted_color = cx.theme().status().git().deleted;
568    deleted_color.fade_out(0.7);
569    deleted_color
570}
571
572fn editor_with_deleted_text(
573    diff_base_buffer: Model<Buffer>,
574    deleted_text_range: Range<usize>,
575    deleted_color: Hsla,
576    cx: &mut ViewContext<'_, Editor>,
577) -> (u8, View<Editor>) {
578    let editor = cx.new_view(|cx| {
579        let multi_buffer =
580            cx.new_model(|_| MultiBuffer::without_headers(0, language::Capability::ReadOnly));
581        multi_buffer.update(cx, |multi_buffer, cx| {
582            multi_buffer.push_excerpts(
583                diff_base_buffer,
584                Some(ExcerptRange {
585                    context: deleted_text_range,
586                    primary: None,
587                }),
588                cx,
589            );
590        });
591
592        let mut editor = Editor::for_multibuffer(multi_buffer, None, cx);
593        editor.soft_wrap_mode_override = Some(language::language_settings::SoftWrap::None);
594        editor.show_wrap_guides = Some(false);
595        editor.show_gutter = false;
596        editor.scroll_manager.set_forbid_vertical_scroll(true);
597        editor.set_read_only(true);
598
599        let editor_snapshot = editor.snapshot(cx);
600        let start = editor_snapshot.buffer_snapshot.anchor_before(0);
601        let end = editor_snapshot
602            .buffer_snapshot
603            .anchor_after(editor.buffer.read(cx).len(cx));
604
605        editor.highlight_rows::<DiffRowHighlight>(start..end, Some(deleted_color), cx);
606        editor
607    });
608
609    let editor_height = editor.update(cx, |editor, cx| editor.max_point(cx).row() as u8);
610    (editor_height, editor)
611}
612
613fn buffer_diff_hunk(
614    buffer_snapshot: &MultiBufferSnapshot,
615    row_range: Range<Point>,
616) -> Option<DiffHunk<u32>> {
617    let mut hunks = buffer_snapshot.git_diff_hunks_in_range(row_range.start.row..row_range.end.row);
618    let hunk = hunks.next()?;
619    let second_hunk = hunks.next();
620    if second_hunk.is_none() {
621        return Some(hunk);
622    }
623    None
624}