custom_highlights.rs

  1use collections::BTreeMap;
  2use gpui::HighlightStyle;
  3use language::Chunk;
  4use multi_buffer::{MultiBufferChunks, MultiBufferSnapshot, ToOffset as _};
  5use std::{
  6    cmp,
  7    iter::{self, Peekable},
  8    ops::Range,
  9    vec,
 10};
 11
 12use crate::display_map::{HighlightKey, TextHighlights};
 13
 14pub struct CustomHighlightsChunks<'a> {
 15    buffer_chunks: MultiBufferChunks<'a>,
 16    buffer_chunk: Option<Chunk<'a>>,
 17    offset: usize,
 18    multibuffer_snapshot: &'a MultiBufferSnapshot,
 19
 20    highlight_endpoints: Peekable<vec::IntoIter<HighlightEndpoint>>,
 21    active_highlights: BTreeMap<HighlightKey, HighlightStyle>,
 22    text_highlights: Option<&'a TextHighlights>,
 23}
 24
 25#[derive(Debug, Copy, Clone, Eq, PartialEq)]
 26struct HighlightEndpoint {
 27    offset: usize,
 28    tag: HighlightKey,
 29    style: Option<HighlightStyle>,
 30}
 31
 32impl<'a> CustomHighlightsChunks<'a> {
 33    pub fn new(
 34        range: Range<usize>,
 35        language_aware: bool,
 36        text_highlights: Option<&'a TextHighlights>,
 37        multibuffer_snapshot: &'a MultiBufferSnapshot,
 38    ) -> Self {
 39        Self {
 40            buffer_chunks: multibuffer_snapshot.chunks(range.clone(), language_aware),
 41            buffer_chunk: None,
 42            offset: range.start,
 43            text_highlights,
 44            highlight_endpoints: create_highlight_endpoints(
 45                &range,
 46                text_highlights,
 47                multibuffer_snapshot,
 48            ),
 49            active_highlights: Default::default(),
 50            multibuffer_snapshot,
 51        }
 52    }
 53
 54    pub fn seek(&mut self, new_range: Range<usize>) {
 55        self.highlight_endpoints =
 56            create_highlight_endpoints(&new_range, self.text_highlights, self.multibuffer_snapshot);
 57        self.offset = new_range.start;
 58        self.buffer_chunks.seek(new_range);
 59        self.buffer_chunk.take();
 60        self.active_highlights.clear()
 61    }
 62}
 63
 64fn create_highlight_endpoints(
 65    range: &Range<usize>,
 66    text_highlights: Option<&TextHighlights>,
 67    buffer: &MultiBufferSnapshot,
 68) -> iter::Peekable<vec::IntoIter<HighlightEndpoint>> {
 69    let mut highlight_endpoints = Vec::new();
 70    if let Some(text_highlights) = text_highlights {
 71        let start = buffer.anchor_after(range.start);
 72        let end = buffer.anchor_after(range.end);
 73        for (&tag, text_highlights) in text_highlights.iter() {
 74            let style = text_highlights.0;
 75            let ranges = &text_highlights.1;
 76
 77            let start_ix = match ranges.binary_search_by(|probe| {
 78                let cmp = probe.end.cmp(&start, buffer);
 79                if cmp.is_gt() {
 80                    cmp::Ordering::Greater
 81                } else {
 82                    cmp::Ordering::Less
 83                }
 84            }) {
 85                Ok(i) | Err(i) => i,
 86            };
 87
 88            for range in &ranges[start_ix..] {
 89                if range.start.cmp(&end, buffer).is_ge() {
 90                    break;
 91                }
 92
 93                let start = range.start.to_offset(buffer);
 94                let end = range.end.to_offset(buffer);
 95                if start == end {
 96                    continue;
 97                }
 98                highlight_endpoints.push(HighlightEndpoint {
 99                    offset: start,
100                    tag,
101                    style: Some(style),
102                });
103                highlight_endpoints.push(HighlightEndpoint {
104                    offset: end,
105                    tag,
106                    style: None,
107                });
108            }
109        }
110        highlight_endpoints.sort();
111    }
112    highlight_endpoints.into_iter().peekable()
113}
114
115impl<'a> Iterator for CustomHighlightsChunks<'a> {
116    type Item = Chunk<'a>;
117
118    fn next(&mut self) -> Option<Self::Item> {
119        let mut next_highlight_endpoint = usize::MAX;
120        while let Some(endpoint) = self.highlight_endpoints.peek().copied() {
121            if endpoint.offset <= self.offset {
122                if let Some(style) = endpoint.style {
123                    self.active_highlights.insert(endpoint.tag, style);
124                } else {
125                    self.active_highlights.remove(&endpoint.tag);
126                }
127                self.highlight_endpoints.next();
128            } else {
129                next_highlight_endpoint = endpoint.offset;
130                break;
131            }
132        }
133
134        let chunk = match &mut self.buffer_chunk {
135            Some(it) => it,
136            slot => slot.insert(self.buffer_chunks.next()?),
137        };
138        while chunk.text.is_empty() {
139            *chunk = self.buffer_chunks.next()?;
140        }
141
142        let split_idx = chunk.text.len().min(next_highlight_endpoint - self.offset);
143        let (prefix, suffix) = chunk.text.split_at(split_idx);
144        self.offset += prefix.len();
145
146        let mask = 1u128.unbounded_shl(split_idx as u32).wrapping_sub(1);
147        let chars = chunk.chars & mask;
148        let tabs = chunk.tabs & mask;
149        let mut prefix = Chunk {
150            text: prefix,
151            chars,
152            tabs,
153            ..chunk.clone()
154        };
155
156        chunk.chars = chunk.chars.unbounded_shr(split_idx as u32);
157        chunk.tabs = chunk.tabs.unbounded_shr(split_idx as u32);
158        chunk.text = suffix;
159        if !self.active_highlights.is_empty() {
160            prefix.highlight_style = self
161                .active_highlights
162                .values()
163                .copied()
164                .reduce(|acc, active_highlight| acc.highlight(active_highlight));
165        }
166        Some(prefix)
167    }
168}
169
170impl PartialOrd for HighlightEndpoint {
171    fn partial_cmp(&self, other: &Self) -> Option<cmp::Ordering> {
172        Some(self.cmp(other))
173    }
174}
175
176impl Ord for HighlightEndpoint {
177    fn cmp(&self, other: &Self) -> cmp::Ordering {
178        self.offset
179            .cmp(&other.offset)
180            .then_with(|| self.style.is_some().cmp(&other.style.is_some()))
181    }
182}
183
184#[cfg(test)]
185mod tests {
186    use std::{any::TypeId, sync::Arc};
187
188    use super::*;
189    use crate::MultiBuffer;
190    use gpui::App;
191    use rand::prelude::*;
192    use util::RandomCharIter;
193
194    #[gpui::test(iterations = 100)]
195    fn test_random_chunk_bitmaps(cx: &mut App, mut rng: StdRng) {
196        // Generate random buffer using existing test infrastructure
197        let len = rng.random_range(10..10000);
198        let buffer = if rng.random() {
199            let text = RandomCharIter::new(&mut rng).take(len).collect::<String>();
200            MultiBuffer::build_simple(&text, cx)
201        } else {
202            MultiBuffer::build_random(&mut rng, cx)
203        };
204
205        let buffer_snapshot = buffer.read(cx).snapshot(cx);
206
207        // Create random highlights
208        let mut highlights = sum_tree::TreeMap::default();
209        let highlight_count = rng.random_range(1..10);
210
211        for _i in 0..highlight_count {
212            let style = HighlightStyle {
213                color: Some(gpui::Hsla {
214                    h: rng.random::<f32>(),
215                    s: rng.random::<f32>(),
216                    l: rng.random::<f32>(),
217                    a: 1.0,
218                }),
219                ..Default::default()
220            };
221
222            let mut ranges = Vec::new();
223            let range_count = rng.random_range(1..10);
224            let text = buffer_snapshot.text();
225            for _ in 0..range_count {
226                if buffer_snapshot.len() == 0 {
227                    continue;
228                }
229
230                let mut start = rng.random_range(0..=buffer_snapshot.len().saturating_sub(10));
231
232                while !text.is_char_boundary(start) {
233                    start = start.saturating_sub(1);
234                }
235
236                let end_end = buffer_snapshot.len().min(start + 100);
237                let mut end = rng.random_range(start..=end_end);
238                while !text.is_char_boundary(end) {
239                    end = end.saturating_sub(1);
240                }
241
242                if start < end {
243                    start = end;
244                }
245                let start_anchor = buffer_snapshot.anchor_before(start);
246                let end_anchor = buffer_snapshot.anchor_after(end);
247                ranges.push(start_anchor..end_anchor);
248            }
249
250            let type_id = TypeId::of::<()>(); // Simple type ID for testing
251            highlights.insert(HighlightKey::Type(type_id), Arc::new((style, ranges)));
252        }
253
254        // Get all chunks and verify their bitmaps
255        let chunks =
256            CustomHighlightsChunks::new(0..buffer_snapshot.len(), false, None, &buffer_snapshot);
257
258        for chunk in chunks {
259            let chunk_text = chunk.text;
260            let chars_bitmap = chunk.chars;
261            let tabs_bitmap = chunk.tabs;
262
263            // Check empty chunks have empty bitmaps
264            if chunk_text.is_empty() {
265                assert_eq!(
266                    chars_bitmap, 0,
267                    "Empty chunk should have empty chars bitmap"
268                );
269                assert_eq!(tabs_bitmap, 0, "Empty chunk should have empty tabs bitmap");
270                continue;
271            }
272
273            // Verify that chunk text doesn't exceed 128 bytes
274            assert!(
275                chunk_text.len() <= 128,
276                "Chunk text length {} exceeds 128 bytes",
277                chunk_text.len()
278            );
279
280            // Verify chars bitmap
281            let char_indices = chunk_text
282                .char_indices()
283                .map(|(i, _)| i)
284                .collect::<Vec<_>>();
285
286            for byte_idx in 0..chunk_text.len() {
287                let should_have_bit = char_indices.contains(&byte_idx);
288                let has_bit = chars_bitmap & (1 << byte_idx) != 0;
289
290                if has_bit != should_have_bit {
291                    eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
292                    eprintln!("Char indices: {:?}", char_indices);
293                    eprintln!("Chars bitmap: {:#b}", chars_bitmap);
294                    assert_eq!(
295                        has_bit, should_have_bit,
296                        "Chars bitmap mismatch at byte index {} in chunk {:?}. Expected bit: {}, Got bit: {}",
297                        byte_idx, chunk_text, should_have_bit, has_bit
298                    );
299                }
300            }
301
302            // Verify tabs bitmap
303            for (byte_idx, byte) in chunk_text.bytes().enumerate() {
304                let is_tab = byte == b'\t';
305                let has_bit = tabs_bitmap & (1 << byte_idx) != 0;
306
307                if has_bit != is_tab {
308                    eprintln!("Chunk text bytes: {:?}", chunk_text.as_bytes());
309                    eprintln!("Tabs bitmap: {:#b}", tabs_bitmap);
310                    assert_eq!(
311                        has_bit, is_tab,
312                        "Tabs bitmap mismatch at byte index {} in chunk {:?}. Byte: {:?}, Expected bit: {}, Got bit: {}",
313                        byte_idx, chunk_text, byte as char, is_tab, has_bit
314                    );
315                }
316            }
317        }
318    }
319}