1use anyhow::Result;
2use buffer_diff::BufferDiff;
3use editor::{MultiBuffer, PathKey, multibuffer_context_lines};
4use gpui::{App, AppContext, AsyncApp, Context, Entity, Subscription, Task};
5use itertools::Itertools;
6use language::{
7 Anchor, Buffer, Capability, LanguageRegistry, OffsetRangeExt as _, Point, TextBuffer,
8};
9use std::{cmp::Reverse, ops::Range, path::Path, sync::Arc};
10use util::ResultExt;
11
12pub enum Diff {
13 Pending(PendingDiff),
14 Finalized(FinalizedDiff),
15}
16
17impl Diff {
18 pub fn finalized(
19 path: String,
20 old_text: Option<String>,
21 new_text: String,
22 language_registry: Arc<LanguageRegistry>,
23 cx: &mut Context<Self>,
24 ) -> Self {
25 let multibuffer = cx.new(|_cx| MultiBuffer::without_headers(Capability::ReadOnly));
26 let new_buffer = cx.new(|cx| Buffer::local(new_text, cx));
27 let base_text = old_text.clone().unwrap_or(String::new()).into();
28 let task = cx.spawn({
29 let multibuffer = multibuffer.clone();
30 let path = path.clone();
31 let buffer = new_buffer.clone();
32 async move |_, cx| {
33 let language = language_registry
34 .load_language_for_file_path(Path::new(&path))
35 .await
36 .log_err();
37
38 buffer.update(cx, |buffer, cx| buffer.set_language(language.clone(), cx));
39
40 let diff = build_buffer_diff(
41 old_text.unwrap_or("".into()).into(),
42 &buffer,
43 Some(language_registry.clone()),
44 cx,
45 )
46 .await?;
47
48 multibuffer.update(cx, |multibuffer, cx| {
49 let hunk_ranges = {
50 let buffer = buffer.read(cx);
51 diff.read(cx)
52 .snapshot(cx)
53 .hunks_intersecting_range(
54 Anchor::min_for_buffer(buffer.remote_id())
55 ..Anchor::max_for_buffer(buffer.remote_id()),
56 buffer,
57 )
58 .map(|diff_hunk| diff_hunk.buffer_range.to_point(buffer))
59 .collect::<Vec<_>>()
60 };
61
62 multibuffer.set_excerpts_for_path(
63 PathKey::for_buffer(&buffer, cx),
64 buffer.clone(),
65 hunk_ranges,
66 multibuffer_context_lines(cx),
67 cx,
68 );
69 multibuffer.add_diff(diff, cx);
70 });
71
72 anyhow::Ok(())
73 }
74 });
75
76 Self::Finalized(FinalizedDiff {
77 multibuffer,
78 path,
79 base_text,
80 new_buffer,
81 _update_diff: task,
82 })
83 }
84
85 pub fn new(buffer: Entity<Buffer>, cx: &mut Context<Self>) -> Self {
86 let buffer_text_snapshot = buffer.read(cx).text_snapshot();
87 let language = buffer.read(cx).language().cloned();
88 let language_registry = buffer.read(cx).language_registry();
89 let buffer_diff = cx.new(|cx| {
90 let mut diff = BufferDiff::new_unchanged(&buffer_text_snapshot, cx);
91 diff.language_changed(language.clone(), language_registry.clone(), cx);
92 let secondary_diff = cx.new(|cx| {
93 let mut diff = BufferDiff::new_unchanged(&buffer_text_snapshot, cx);
94 diff.language_changed(language, language_registry, cx);
95 diff
96 });
97 diff.set_secondary_diff(secondary_diff);
98 diff
99 });
100
101 let multibuffer = cx.new(|cx| {
102 let mut multibuffer = MultiBuffer::without_headers(Capability::ReadOnly);
103 multibuffer.add_diff(buffer_diff.clone(), cx);
104 multibuffer
105 });
106
107 Self::Pending(PendingDiff {
108 multibuffer,
109 base_text: Arc::from(buffer_text_snapshot.text().as_str()),
110 _subscription: cx.observe(&buffer, |this, _, cx| {
111 if let Diff::Pending(diff) = this {
112 diff.update(cx);
113 }
114 }),
115 new_buffer: buffer,
116 diff: buffer_diff,
117 revealed_ranges: Vec::new(),
118 update_diff: Task::ready(Ok(())),
119 })
120 }
121
122 pub fn reveal_range(&mut self, range: Range<Anchor>, cx: &mut Context<Self>) {
123 if let Self::Pending(diff) = self {
124 diff.reveal_range(range, cx);
125 }
126 }
127
128 pub fn finalize(&mut self, cx: &mut Context<Self>) {
129 if let Self::Pending(diff) = self {
130 *self = Self::Finalized(diff.finalize(cx));
131 }
132 }
133
134 /// Returns the original text before any edits were applied.
135 pub fn base_text(&self) -> &Arc<str> {
136 match self {
137 Self::Pending(PendingDiff { base_text, .. }) => base_text,
138 Self::Finalized(FinalizedDiff { base_text, .. }) => base_text,
139 }
140 }
141
142 /// Returns the buffer being edited (for pending diffs) or the snapshot buffer (for finalized diffs).
143 pub fn buffer(&self) -> &Entity<Buffer> {
144 match self {
145 Self::Pending(PendingDiff { new_buffer, .. }) => new_buffer,
146 Self::Finalized(FinalizedDiff { new_buffer, .. }) => new_buffer,
147 }
148 }
149
150 pub fn multibuffer(&self) -> &Entity<MultiBuffer> {
151 match self {
152 Self::Pending(PendingDiff { multibuffer, .. }) => multibuffer,
153 Self::Finalized(FinalizedDiff { multibuffer, .. }) => multibuffer,
154 }
155 }
156
157 pub fn to_markdown(&self, cx: &App) -> String {
158 let buffer_text = self
159 .multibuffer()
160 .read(cx)
161 .all_buffers()
162 .iter()
163 .map(|buffer| buffer.read(cx).text())
164 .join("\n");
165 let path = match self {
166 Diff::Pending(PendingDiff {
167 new_buffer: buffer, ..
168 }) => buffer
169 .read(cx)
170 .file()
171 .map(|file| file.path().display(file.path_style(cx))),
172 Diff::Finalized(FinalizedDiff { path, .. }) => Some(path.as_str().into()),
173 };
174 format!(
175 "Diff: {}\n```\n{}\n```\n",
176 path.unwrap_or("untitled".into()),
177 buffer_text
178 )
179 }
180
181 pub fn has_revealed_range(&self, cx: &App) -> bool {
182 self.multibuffer().read(cx).paths().next().is_some()
183 }
184
185 pub fn needs_update(&self, old_text: &str, new_text: &str, cx: &App) -> bool {
186 match self {
187 Diff::Pending(PendingDiff {
188 base_text,
189 new_buffer,
190 ..
191 }) => {
192 base_text.as_ref() != old_text
193 || !new_buffer.read(cx).as_rope().chunks().equals_str(new_text)
194 }
195 Diff::Finalized(FinalizedDiff {
196 base_text,
197 new_buffer,
198 ..
199 }) => {
200 base_text.as_ref() != old_text
201 || !new_buffer.read(cx).as_rope().chunks().equals_str(new_text)
202 }
203 }
204 }
205}
206
207pub struct PendingDiff {
208 multibuffer: Entity<MultiBuffer>,
209 base_text: Arc<str>,
210 new_buffer: Entity<Buffer>,
211 diff: Entity<BufferDiff>,
212 revealed_ranges: Vec<Range<Anchor>>,
213 _subscription: Subscription,
214 update_diff: Task<Result<()>>,
215}
216
217impl PendingDiff {
218 pub fn update(&mut self, cx: &mut Context<Diff>) {
219 let buffer = self.new_buffer.clone();
220 let buffer_diff = self.diff.clone();
221 let base_text = self.base_text.clone();
222 self.update_diff = cx.spawn(async move |diff, cx| {
223 let text_snapshot = buffer.read_with(cx, |buffer, _| buffer.text_snapshot());
224 let language = buffer.read_with(cx, |buffer, _| buffer.language().cloned());
225 let update = buffer_diff
226 .update(cx, |diff, cx| {
227 diff.update_diff(
228 text_snapshot.clone(),
229 Some(base_text.clone()),
230 false,
231 language,
232 cx,
233 )
234 })
235 .await;
236 let (task1, task2) = buffer_diff.update(cx, |diff, cx| {
237 let task1 = diff.set_snapshot(update.clone(), &text_snapshot, cx);
238 let task2 = diff
239 .secondary_diff()
240 .unwrap()
241 .update(cx, |diff, cx| diff.set_snapshot(update, &text_snapshot, cx));
242 (task1, task2)
243 });
244 task1.await;
245 task2.await;
246 diff.update(cx, |diff, cx| {
247 if let Diff::Pending(diff) = diff {
248 diff.update_visible_ranges(cx);
249 }
250 })
251 });
252 }
253
254 pub fn reveal_range(&mut self, range: Range<Anchor>, cx: &mut Context<Diff>) {
255 self.revealed_ranges.push(range);
256 self.update_visible_ranges(cx);
257 }
258
259 fn finalize(&self, cx: &mut Context<Diff>) -> FinalizedDiff {
260 let ranges = self.excerpt_ranges(cx);
261 let base_text = self.base_text.clone();
262 let new_buffer = self.new_buffer.read(cx);
263 let language_registry = new_buffer.language_registry();
264
265 let path = new_buffer
266 .file()
267 .map(|file| file.path().display(file.path_style(cx)))
268 .unwrap_or("untitled".into())
269 .into();
270 let replica_id = new_buffer.replica_id();
271
272 // Replace the buffer in the multibuffer with the snapshot
273 let buffer = cx.new(|cx| {
274 let language = self.new_buffer.read(cx).language().cloned();
275 let buffer = TextBuffer::new_normalized(
276 replica_id,
277 cx.entity_id().as_non_zero_u64().into(),
278 self.new_buffer.read(cx).line_ending(),
279 self.new_buffer.read(cx).as_rope().clone(),
280 );
281 let mut buffer = Buffer::build(buffer, None, Capability::ReadWrite);
282 buffer.set_language(language, cx);
283 buffer
284 });
285
286 let buffer_diff = cx.spawn({
287 let buffer = buffer.clone();
288 async move |_this, cx| {
289 build_buffer_diff(base_text, &buffer, language_registry, cx).await
290 }
291 });
292
293 let update_diff = cx.spawn(async move |this, cx| {
294 let buffer_diff = buffer_diff.await?;
295 this.update(cx, |this, cx| {
296 this.multibuffer().update(cx, |multibuffer, cx| {
297 let path_key = PathKey::for_buffer(&buffer, cx);
298 multibuffer.clear(cx);
299 multibuffer.set_excerpts_for_path(
300 path_key,
301 buffer,
302 ranges,
303 multibuffer_context_lines(cx),
304 cx,
305 );
306 multibuffer.add_diff(buffer_diff.clone(), cx);
307 });
308
309 cx.notify();
310 })
311 });
312
313 FinalizedDiff {
314 path,
315 base_text: self.base_text.clone(),
316 multibuffer: self.multibuffer.clone(),
317 new_buffer: self.new_buffer.clone(),
318 _update_diff: update_diff,
319 }
320 }
321
322 fn update_visible_ranges(&mut self, cx: &mut Context<Diff>) {
323 let ranges = self.excerpt_ranges(cx);
324 self.multibuffer.update(cx, |multibuffer, cx| {
325 multibuffer.set_excerpts_for_path(
326 PathKey::for_buffer(&self.new_buffer, cx),
327 self.new_buffer.clone(),
328 ranges,
329 multibuffer_context_lines(cx),
330 cx,
331 );
332 let end = multibuffer.len(cx);
333 Some(multibuffer.snapshot(cx).offset_to_point(end).row + 1)
334 });
335 cx.notify();
336 }
337
338 fn excerpt_ranges(&self, cx: &App) -> Vec<Range<Point>> {
339 let buffer = self.new_buffer.read(cx);
340 let mut ranges = self
341 .diff
342 .read(cx)
343 .snapshot(cx)
344 .hunks_intersecting_range(
345 Anchor::min_for_buffer(buffer.remote_id())
346 ..Anchor::max_for_buffer(buffer.remote_id()),
347 buffer,
348 )
349 .map(|diff_hunk| diff_hunk.buffer_range.to_point(buffer))
350 .collect::<Vec<_>>();
351 ranges.extend(
352 self.revealed_ranges
353 .iter()
354 .map(|range| range.to_point(buffer)),
355 );
356 ranges.sort_unstable_by_key(|range| (range.start, Reverse(range.end)));
357
358 // Merge adjacent ranges
359 let mut ranges = ranges.into_iter().peekable();
360 let mut merged_ranges = Vec::new();
361 while let Some(mut range) = ranges.next() {
362 while let Some(next_range) = ranges.peek() {
363 if range.end >= next_range.start {
364 range.end = range.end.max(next_range.end);
365 ranges.next();
366 } else {
367 break;
368 }
369 }
370
371 merged_ranges.push(range);
372 }
373 merged_ranges
374 }
375}
376
377pub struct FinalizedDiff {
378 path: String,
379 base_text: Arc<str>,
380 new_buffer: Entity<Buffer>,
381 multibuffer: Entity<MultiBuffer>,
382 _update_diff: Task<Result<()>>,
383}
384
385async fn build_buffer_diff(
386 old_text: Arc<str>,
387 buffer: &Entity<Buffer>,
388 language_registry: Option<Arc<LanguageRegistry>>,
389 cx: &mut AsyncApp,
390) -> Result<Entity<BufferDiff>> {
391 let language = cx.update(|cx| buffer.read(cx).language().cloned());
392 let text_snapshot = cx.update(|cx| buffer.read(cx).text_snapshot());
393 let buffer = cx.update(|cx| buffer.read(cx).snapshot());
394
395 let secondary_diff = cx.new(|cx| BufferDiff::new(&buffer, cx));
396
397 let update = secondary_diff
398 .update(cx, |secondary_diff, cx| {
399 secondary_diff.update_diff(
400 text_snapshot.clone(),
401 Some(old_text),
402 true,
403 language.clone(),
404 cx,
405 )
406 })
407 .await;
408
409 secondary_diff
410 .update(cx, |secondary_diff, cx| {
411 secondary_diff.language_changed(language.clone(), language_registry.clone(), cx);
412 secondary_diff.set_snapshot(update.clone(), &buffer, cx)
413 })
414 .await;
415
416 let diff = cx.new(|cx| BufferDiff::new(&buffer, cx));
417 diff.update(cx, |diff, cx| {
418 diff.language_changed(language, language_registry, cx);
419 diff.set_secondary_diff(secondary_diff);
420 diff.set_snapshot(update.clone(), &buffer, cx)
421 })
422 .await;
423 Ok(diff)
424}
425
426#[cfg(test)]
427mod tests {
428 use gpui::{AppContext as _, TestAppContext};
429 use language::Buffer;
430
431 use crate::Diff;
432
433 #[gpui::test]
434 async fn test_pending_diff(cx: &mut TestAppContext) {
435 let buffer = cx.new(|cx| Buffer::local("hello!", cx));
436 let _diff = cx.new(|cx| Diff::new(buffer.clone(), cx));
437 buffer.update(cx, |buffer, cx| {
438 buffer.set_text("HELLO!", cx);
439 });
440 cx.run_until_parked();
441 }
442}