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