1use crate::{OffsetUtf16, Point, PointUtf16, TextSummary, Unclipped};
2use arrayvec::ArrayString;
3use std::{cmp, ops::Range};
4use sum_tree::Bias;
5use unicode_segmentation::GraphemeCursor;
6use util::debug_panic;
7
8#[cfg(not(all(test, not(rust_analyzer))))]
9pub(crate) type Bitmap = u128;
10#[cfg(all(test, not(rust_analyzer)))]
11pub(crate) type Bitmap = u16;
12
13pub(crate) const MIN_BASE: usize = MAX_BASE / 2;
14pub(crate) const MAX_BASE: usize = Bitmap::BITS as usize;
15
16#[derive(Clone, Debug, Default)]
17pub struct Chunk {
18 /// If bit[i] is set, then the character at index i is the start of a UTF-8 character in the
19 /// text.
20 chars: Bitmap,
21 /// The number of set bits is the number of UTF-16 code units it would take to represent the
22 /// text.
23 ///
24 /// Bit[i] is set if text[i] is the start of a UTF-8 character. If the character would
25 /// take two UTF-16 code units, then bit[i+1] is also set. (Rust chars never take more
26 /// than two UTF-16 code units.)
27 chars_utf16: Bitmap,
28 /// If bit[i] is set, then the character at index i is an ascii newline.
29 newlines: Bitmap,
30 /// If bit[i] is set, then the character at index i is an ascii tab.
31 tabs: Bitmap,
32 pub text: ArrayString<MAX_BASE>,
33}
34
35impl Chunk {
36 pub const MASK_BITS: usize = Bitmap::BITS as usize;
37
38 #[inline(always)]
39 pub fn new(text: &str) -> Self {
40 let mut this = Chunk::default();
41 this.push_str(text);
42 this
43 }
44
45 #[inline(always)]
46 pub fn push_str(&mut self, text: &str) {
47 for (char_ix, c) in text.char_indices() {
48 let ix = self.text.len() + char_ix;
49 self.chars |= 1 << ix;
50 self.chars_utf16 |= 1 << ix;
51 self.chars_utf16 |= (c.len_utf16() as Bitmap) << ix;
52 self.newlines |= ((c == '\n') as Bitmap) << ix;
53 self.tabs |= ((c == '\t') as Bitmap) << ix;
54 }
55 self.text.push_str(text);
56 }
57
58 #[inline(always)]
59 pub fn append(&mut self, slice: ChunkSlice) {
60 if slice.is_empty() {
61 return;
62 };
63
64 let base_ix = self.text.len();
65 self.chars |= slice.chars << base_ix;
66 self.chars_utf16 |= slice.chars_utf16 << base_ix;
67 self.newlines |= slice.newlines << base_ix;
68 self.tabs |= slice.tabs << base_ix;
69 self.text.push_str(slice.text);
70 }
71
72 #[inline(always)]
73 pub fn as_slice(&self) -> ChunkSlice<'_> {
74 ChunkSlice {
75 chars: self.chars,
76 chars_utf16: self.chars_utf16,
77 newlines: self.newlines,
78 tabs: self.tabs,
79 text: &self.text,
80 }
81 }
82
83 #[inline(always)]
84 pub fn slice(&self, range: Range<usize>) -> ChunkSlice<'_> {
85 self.as_slice().slice(range)
86 }
87
88 #[inline(always)]
89 pub fn chars(&self) -> Bitmap {
90 self.chars
91 }
92
93 pub fn tabs(&self) -> Bitmap {
94 self.tabs
95 }
96
97 #[inline(always)]
98 pub fn is_char_boundary(&self, offset: usize) -> bool {
99 (1 as Bitmap).unbounded_shl(offset as u32) & self.chars != 0 || offset == self.text.len()
100 }
101
102 pub fn floor_char_boundary(&self, index: usize) -> usize {
103 #[inline]
104 pub(crate) const fn is_utf8_char_boundary(u8: u8) -> bool {
105 // This is bit magic equivalent to: b < 128 || b >= 192
106 (u8 as i8) >= -0x40
107 }
108
109 if index >= self.text.len() {
110 self.text.len()
111 } else {
112 let mut i = index;
113 while i > 0 {
114 if is_utf8_char_boundary(self.text.as_bytes()[i]) {
115 break;
116 }
117 i -= 1;
118 }
119
120 i
121 }
122 }
123
124 #[track_caller]
125 #[inline(always)]
126 pub fn assert_char_boundary(&self, offset: usize) {
127 if self.is_char_boundary(offset) {
128 return;
129 }
130 panic_char_boundary(self, offset);
131
132 #[cold]
133 #[inline(never)]
134 fn panic_char_boundary(chunk: &Chunk, offset: usize) {
135 if offset > chunk.text.len() {
136 panic!(
137 "byte index {} is out of bounds of `{:?}` (length: {})",
138 offset,
139 chunk.text,
140 chunk.text.len()
141 );
142 }
143 // find the character
144 let char_start = chunk.floor_char_boundary(offset);
145 // `char_start` must be less than len and a char boundary
146 let ch = chunk
147 .text
148 .get(char_start..)
149 .unwrap()
150 .chars()
151 .next()
152 .unwrap();
153 let char_range = char_start..char_start + ch.len_utf8();
154 panic!(
155 "byte index {} is not a char boundary; it is inside {:?} (bytes {:?})",
156 offset, ch, char_range,
157 );
158 }
159 }
160}
161
162#[derive(Clone, Copy, Debug)]
163pub struct ChunkSlice<'a> {
164 chars: Bitmap,
165 chars_utf16: Bitmap,
166 newlines: Bitmap,
167 tabs: Bitmap,
168 text: &'a str,
169}
170
171impl Into<Chunk> for ChunkSlice<'_> {
172 fn into(self) -> Chunk {
173 Chunk {
174 chars: self.chars,
175 chars_utf16: self.chars_utf16,
176 newlines: self.newlines,
177 tabs: self.tabs,
178 text: self.text.try_into().unwrap(),
179 }
180 }
181}
182
183impl<'a> ChunkSlice<'a> {
184 #[inline(always)]
185 pub fn is_empty(&self) -> bool {
186 self.text.is_empty()
187 }
188
189 #[inline(always)]
190 pub fn is_char_boundary(&self, offset: usize) -> bool {
191 (1 as Bitmap).unbounded_shl(offset as u32) & self.chars != 0 || offset == self.text.len()
192 }
193
194 #[inline(always)]
195 pub fn split_at(self, mid: usize) -> (ChunkSlice<'a>, ChunkSlice<'a>) {
196 if mid == MAX_BASE {
197 let left = self;
198 let right = ChunkSlice {
199 chars: 0,
200 chars_utf16: 0,
201 newlines: 0,
202 tabs: 0,
203 text: "",
204 };
205 (left, right)
206 } else {
207 let mask = ((1 as Bitmap) << mid) - 1;
208 let (left_text, right_text) = self.text.split_at(mid);
209 let left = ChunkSlice {
210 chars: self.chars & mask,
211 chars_utf16: self.chars_utf16 & mask,
212 newlines: self.newlines & mask,
213 tabs: self.tabs & mask,
214 text: left_text,
215 };
216 let right = ChunkSlice {
217 chars: self.chars >> mid,
218 chars_utf16: self.chars_utf16 >> mid,
219 newlines: self.newlines >> mid,
220 tabs: self.tabs >> mid,
221 text: right_text,
222 };
223 (left, right)
224 }
225 }
226
227 #[inline(always)]
228 pub fn slice(self, range: Range<usize>) -> Self {
229 let mask = (1 as Bitmap)
230 .unbounded_shl(range.end as u32)
231 .wrapping_sub(1);
232 if range.start == MAX_BASE {
233 Self {
234 chars: 0,
235 chars_utf16: 0,
236 newlines: 0,
237 tabs: 0,
238 text: "",
239 }
240 } else {
241 self.assert_char_boundary(range.start);
242 self.assert_char_boundary(range.end);
243 Self {
244 chars: (self.chars & mask) >> range.start,
245 chars_utf16: (self.chars_utf16 & mask) >> range.start,
246 newlines: (self.newlines & mask) >> range.start,
247 tabs: (self.tabs & mask) >> range.start,
248 text: &self.text[range],
249 }
250 }
251 }
252
253 #[inline(always)]
254 pub fn text_summary(&self) -> TextSummary {
255 let mut chars = 0;
256 let (longest_row, longest_row_chars) = self.longest_row(&mut chars);
257 TextSummary {
258 len: self.len(),
259 chars,
260 len_utf16: self.len_utf16(),
261 lines: self.lines(),
262 first_line_chars: self.first_line_chars(),
263 last_line_chars: self.last_line_chars(),
264 last_line_len_utf16: self.last_line_len_utf16(),
265 longest_row,
266 longest_row_chars,
267 }
268 }
269
270 /// Get length in bytes
271 #[inline(always)]
272 pub fn len(&self) -> usize {
273 self.text.len()
274 }
275
276 /// Get length in UTF-16 code units
277 #[inline(always)]
278 pub fn len_utf16(&self) -> OffsetUtf16 {
279 OffsetUtf16(self.chars_utf16.count_ones() as usize)
280 }
281
282 /// Get point representing number of lines and length of last line
283 #[inline(always)]
284 pub fn lines(&self) -> Point {
285 let row = self.newlines.count_ones();
286 let column = self.newlines.leading_zeros() - (Bitmap::BITS - self.text.len() as u32);
287 Point::new(row, column)
288 }
289
290 /// Get number of chars in first line
291 #[inline(always)]
292 pub fn first_line_chars(&self) -> u32 {
293 if self.newlines == 0 {
294 self.chars.count_ones()
295 } else {
296 let mask = ((1 as Bitmap) << self.newlines.trailing_zeros()) - 1;
297 (self.chars & mask).count_ones()
298 }
299 }
300
301 /// Get number of chars in last line
302 #[inline(always)]
303 pub fn last_line_chars(&self) -> u32 {
304 if self.newlines == 0 {
305 self.chars.count_ones()
306 } else {
307 let mask = !(Bitmap::MAX >> self.newlines.leading_zeros());
308 (self.chars & mask).count_ones()
309 }
310 }
311
312 /// Get number of UTF-16 code units in last line
313 #[inline(always)]
314 pub fn last_line_len_utf16(&self) -> u32 {
315 if self.newlines == 0 {
316 self.chars_utf16.count_ones()
317 } else {
318 let mask = !(Bitmap::MAX >> self.newlines.leading_zeros());
319 (self.chars_utf16 & mask).count_ones()
320 }
321 }
322
323 /// Get the longest row in the chunk and its length in characters.
324 /// Calculate the total number of characters in the chunk along the way.
325 #[inline(always)]
326 pub fn longest_row(&self, total_chars: &mut usize) -> (u32, u32) {
327 let mut chars = self.chars;
328 let mut newlines = self.newlines;
329 *total_chars = 0;
330 let mut row = 0;
331 let mut longest_row = 0;
332 let mut longest_row_chars = 0;
333 while newlines > 0 {
334 let newline_ix = newlines.trailing_zeros();
335 let row_chars = (chars & ((1 << newline_ix) - 1)).count_ones() as u8;
336 *total_chars += usize::from(row_chars);
337 if row_chars > longest_row_chars {
338 longest_row = row;
339 longest_row_chars = row_chars;
340 }
341
342 newlines >>= newline_ix;
343 newlines >>= 1;
344 chars >>= newline_ix;
345 chars >>= 1;
346 row += 1;
347 *total_chars += 1;
348 }
349
350 let row_chars = chars.count_ones() as u8;
351 *total_chars += usize::from(row_chars);
352 if row_chars > longest_row_chars {
353 (row, row_chars as u32)
354 } else {
355 (longest_row, longest_row_chars as u32)
356 }
357 }
358
359 #[inline(always)]
360 pub fn offset_to_point(&self, offset: usize) -> Point {
361 let mask = (1 as Bitmap).unbounded_shl(offset as u32).wrapping_sub(1);
362 let row = (self.newlines & mask).count_ones();
363 let newline_ix = Bitmap::BITS - (self.newlines & mask).leading_zeros();
364 let column = (offset - newline_ix as usize) as u32;
365 Point::new(row, column)
366 }
367
368 #[inline(always)]
369 pub fn point_to_offset(&self, point: Point) -> usize {
370 if point.row > self.lines().row {
371 debug_panic!(
372 "point {:?} extends beyond rows for string {:?}",
373 point,
374 self.text
375 );
376 return self.len();
377 }
378
379 let row_offset_range = self.offset_range_for_row(point.row);
380 if point.column > row_offset_range.len() as u32 {
381 debug_panic!(
382 "point {:?} extends beyond row for string {:?}",
383 point,
384 self.text
385 );
386 row_offset_range.end
387 } else {
388 row_offset_range.start + point.column as usize
389 }
390 }
391
392 #[track_caller]
393 #[inline(always)]
394 pub fn assert_char_boundary(&self, offset: usize) {
395 if self.is_char_boundary(offset) {
396 return;
397 }
398 panic_char_boundary(self, offset);
399
400 #[cold]
401 #[inline(never)]
402 fn panic_char_boundary(chunk: &ChunkSlice, offset: usize) {
403 if offset > chunk.text.len() {
404 panic!(
405 "byte index {} is out of bounds of `{:?}` (length: {})",
406 offset,
407 chunk.text,
408 chunk.text.len()
409 );
410 }
411 // find the character
412 let char_start = chunk.floor_char_boundary(offset);
413 // `char_start` must be less than len and a char boundary
414 let ch = chunk
415 .text
416 .get(char_start..)
417 .unwrap()
418 .chars()
419 .next()
420 .unwrap();
421 let char_range = char_start..char_start + ch.len_utf8();
422 panic!(
423 "byte index {} is not a char boundary; it is inside {:?} (bytes {:?})",
424 offset, ch, char_range,
425 );
426 }
427 }
428
429 pub fn floor_char_boundary(&self, index: usize) -> usize {
430 #[inline]
431 pub(crate) const fn is_utf8_char_boundary(u8: u8) -> bool {
432 // This is bit magic equivalent to: b < 128 || b >= 192
433 (u8 as i8) >= -0x40
434 }
435
436 if index >= self.text.len() {
437 self.text.len()
438 } else {
439 let mut i = index;
440 while i > 0 {
441 if is_utf8_char_boundary(self.text.as_bytes()[i]) {
442 break;
443 }
444 i -= 1;
445 }
446
447 i
448 }
449 }
450
451 #[inline(always)]
452 pub fn offset_to_offset_utf16(&self, offset: usize) -> OffsetUtf16 {
453 let mask = (1 as Bitmap).unbounded_shl(offset as u32).wrapping_sub(1);
454 OffsetUtf16((self.chars_utf16 & mask).count_ones() as usize)
455 }
456
457 #[inline(always)]
458 pub fn offset_utf16_to_offset(&self, target: OffsetUtf16) -> usize {
459 if target.0 == 0 {
460 0
461 } else {
462 #[cfg(not(test))]
463 let chars_utf16 = self.chars_utf16;
464 #[cfg(test)]
465 let chars_utf16 = self.chars_utf16 as u128;
466 let ix = nth_set_bit(chars_utf16, target.0) + 1;
467 if ix == MAX_BASE {
468 MAX_BASE
469 } else {
470 let utf8_additional_len = cmp::min(
471 (self.chars_utf16 >> ix).trailing_zeros() as usize,
472 self.text.len() - ix,
473 );
474 ix + utf8_additional_len
475 }
476 }
477 }
478
479 #[inline(always)]
480 pub fn offset_to_point_utf16(&self, offset: usize) -> PointUtf16 {
481 let mask = (1 as Bitmap).unbounded_shl(offset as u32).wrapping_sub(1);
482 let row = (self.newlines & mask).count_ones();
483 let newline_ix = Bitmap::BITS - (self.newlines & mask).leading_zeros();
484 let column = if newline_ix as usize == MAX_BASE {
485 0
486 } else {
487 ((self.chars_utf16 & mask) >> newline_ix).count_ones()
488 };
489 PointUtf16::new(row, column)
490 }
491
492 #[inline(always)]
493 pub fn point_to_point_utf16(&self, point: Point) -> PointUtf16 {
494 self.offset_to_point_utf16(self.point_to_offset(point))
495 }
496
497 #[inline(always)]
498 pub fn point_utf16_to_offset(&self, point: PointUtf16, clip: bool) -> usize {
499 let lines = self.lines();
500 if point.row > lines.row {
501 if !clip {
502 debug_panic!(
503 "point {:?} is beyond this chunk's extent {:?}",
504 point,
505 self.text
506 );
507 }
508 return self.len();
509 }
510
511 let row_offset_range = self.offset_range_for_row(point.row);
512 let line = self.slice(row_offset_range.clone());
513 if point.column > line.last_line_len_utf16() {
514 if !clip {
515 debug_panic!(
516 "point {:?} is beyond the end of the line in chunk {:?}",
517 point,
518 self.text
519 );
520 }
521 return line.len();
522 }
523
524 let mut offset = row_offset_range.start;
525 if point.column > 0 {
526 offset += line.offset_utf16_to_offset(OffsetUtf16(point.column as usize));
527 if !self.text.is_char_boundary(offset) {
528 offset -= 1;
529 while !self.text.is_char_boundary(offset) {
530 offset -= 1;
531 }
532 if !clip {
533 debug_panic!(
534 "point {:?} is within character in chunk {:?}",
535 point,
536 self.text,
537 );
538 }
539 }
540 }
541 offset
542 }
543
544 #[inline(always)]
545 pub fn unclipped_point_utf16_to_point(&self, point: Unclipped<PointUtf16>) -> Point {
546 let max_point = self.lines();
547 if point.0.row > max_point.row {
548 return max_point;
549 }
550
551 let row_offset_range = self.offset_range_for_row(point.0.row);
552 let line = self.slice(row_offset_range);
553 if point.0.column == 0 {
554 Point::new(point.0.row, 0)
555 } else if point.0.column >= line.len_utf16().0 as u32 {
556 Point::new(point.0.row, line.len() as u32)
557 } else {
558 let mut column = line.offset_utf16_to_offset(OffsetUtf16(point.0.column as usize));
559 while !line.text.is_char_boundary(column) {
560 column -= 1;
561 }
562 Point::new(point.0.row, column as u32)
563 }
564 }
565
566 #[inline(always)]
567 pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
568 let max_point = self.lines();
569 if point.row > max_point.row {
570 return max_point;
571 }
572
573 let line = self.slice(self.offset_range_for_row(point.row));
574 if point.column == 0 {
575 point
576 } else if point.column >= line.len() as u32 {
577 Point::new(point.row, line.len() as u32)
578 } else {
579 let mut column = point.column as usize;
580 let bytes = line.text.as_bytes();
581 if bytes[column - 1] < 128 && bytes[column] < 128 {
582 return Point::new(point.row, column as u32);
583 }
584
585 let mut grapheme_cursor = GraphemeCursor::new(column, bytes.len(), true);
586 loop {
587 if line.is_char_boundary(column)
588 && grapheme_cursor.is_boundary(line.text, 0).unwrap_or(false)
589 {
590 break;
591 }
592
593 match bias {
594 Bias::Left => column -= 1,
595 Bias::Right => column += 1,
596 }
597 grapheme_cursor.set_cursor(column);
598 }
599 Point::new(point.row, column as u32)
600 }
601 }
602
603 #[inline(always)]
604 pub fn clip_point_utf16(&self, point: Unclipped<PointUtf16>, bias: Bias) -> PointUtf16 {
605 let max_point = self.lines();
606 if point.0.row > max_point.row {
607 PointUtf16::new(max_point.row, self.last_line_len_utf16())
608 } else {
609 let line = self.slice(self.offset_range_for_row(point.0.row));
610 let column = line.clip_offset_utf16(OffsetUtf16(point.0.column as usize), bias);
611 PointUtf16::new(point.0.row, column.0 as u32)
612 }
613 }
614
615 #[inline(always)]
616 pub fn clip_offset_utf16(&self, target: OffsetUtf16, bias: Bias) -> OffsetUtf16 {
617 if target == OffsetUtf16::default() {
618 OffsetUtf16::default()
619 } else if target >= self.len_utf16() {
620 self.len_utf16()
621 } else {
622 let mut offset = self.offset_utf16_to_offset(target);
623 while !self.text.is_char_boundary(offset) {
624 if bias == Bias::Left {
625 offset -= 1;
626 } else {
627 offset += 1;
628 }
629 }
630 self.offset_to_offset_utf16(offset)
631 }
632 }
633
634 #[inline(always)]
635 fn offset_range_for_row(&self, row: u32) -> Range<usize> {
636 let row_start = if row > 0 {
637 #[cfg(not(test))]
638 let newlines = self.newlines;
639 #[cfg(test)]
640 let newlines = self.newlines as u128;
641 nth_set_bit(newlines, row as usize) + 1
642 } else {
643 0
644 };
645 let row_len = if row_start == MAX_BASE {
646 0
647 } else {
648 cmp::min(
649 (self.newlines >> row_start).trailing_zeros(),
650 (self.text.len() - row_start) as u32,
651 )
652 };
653 row_start..row_start + row_len as usize
654 }
655
656 #[inline(always)]
657 pub fn tabs(&self) -> Tabs {
658 Tabs {
659 tabs: self.tabs,
660 chars: self.chars,
661 }
662 }
663}
664
665pub struct Tabs {
666 tabs: Bitmap,
667 chars: Bitmap,
668}
669
670#[derive(Debug, PartialEq, Eq)]
671pub struct TabPosition {
672 pub byte_offset: usize,
673 pub char_offset: usize,
674}
675
676impl Iterator for Tabs {
677 type Item = TabPosition;
678
679 fn next(&mut self) -> Option<Self::Item> {
680 if self.tabs == 0 {
681 return None;
682 }
683
684 let tab_offset = self.tabs.trailing_zeros() as usize;
685 let chars_mask = (1 << tab_offset) - 1;
686 let char_offset = (self.chars & chars_mask).count_ones() as usize;
687
688 // Since tabs are 1 byte the tab offset is the same as the byte offset
689 let position = TabPosition {
690 byte_offset: tab_offset,
691 char_offset,
692 };
693 // Remove the tab we've just seen
694 self.tabs ^= 1 << tab_offset;
695
696 Some(position)
697 }
698}
699
700/// Finds the n-th bit that is set to 1.
701#[inline(always)]
702fn nth_set_bit(v: u128, n: usize) -> usize {
703 let low = v as u64;
704 let high = (v >> 64) as u64;
705
706 let low_count = low.count_ones() as usize;
707 if n > low_count {
708 64 + nth_set_bit_u64(high, (n - low_count) as u64) as usize
709 } else {
710 nth_set_bit_u64(low, n as u64) as usize
711 }
712}
713
714#[inline(always)]
715fn nth_set_bit_u64(v: u64, mut n: u64) -> u64 {
716 let v = v.reverse_bits();
717 let mut s: u64 = 64;
718
719 // Parallel bit count intermediates
720 let a = v - ((v >> 1) & (u64::MAX / 3));
721 let b = (a & (u64::MAX / 5)) + ((a >> 2) & (u64::MAX / 5));
722 let c = (b + (b >> 4)) & (u64::MAX / 0x11);
723 let d = (c + (c >> 8)) & (u64::MAX / 0x101);
724
725 // Branchless select
726 let t = (d >> 32) + (d >> 48);
727 s -= (t.wrapping_sub(n) & 256) >> 3;
728 n -= t & (t.wrapping_sub(n) >> 8);
729
730 let t = (d >> (s - 16)) & 0xff;
731 s -= (t.wrapping_sub(n) & 256) >> 4;
732 n -= t & (t.wrapping_sub(n) >> 8);
733
734 let t = (c >> (s - 8)) & 0xf;
735 s -= (t.wrapping_sub(n) & 256) >> 5;
736 n -= t & (t.wrapping_sub(n) >> 8);
737
738 let t = (b >> (s - 4)) & 0x7;
739 s -= (t.wrapping_sub(n) & 256) >> 6;
740 n -= t & (t.wrapping_sub(n) >> 8);
741
742 let t = (a >> (s - 2)) & 0x3;
743 s -= (t.wrapping_sub(n) & 256) >> 7;
744 n -= t & (t.wrapping_sub(n) >> 8);
745
746 let t = (v >> (s - 1)) & 0x1;
747 s -= (t.wrapping_sub(n) & 256) >> 8;
748
749 65 - s - 1
750}
751
752#[cfg(test)]
753mod tests {
754 use super::*;
755 use rand::prelude::*;
756 use util::RandomCharIter;
757
758 #[gpui::test(iterations = 100)]
759 fn test_random_chunks(mut rng: StdRng) {
760 let text = random_string_with_utf8_len(&mut rng, MAX_BASE);
761 log::info!("Chunk: {:?}", text);
762 let chunk = Chunk::new(&text);
763 verify_chunk(chunk.as_slice(), &text);
764
765 // Verify Chunk::chars() bitmap
766 let expected_chars = char_offsets(&text)
767 .into_iter()
768 .inspect(|i| assert!(*i < MAX_BASE))
769 .fold(0 as Bitmap, |acc, i| acc | (1 << i));
770 assert_eq!(chunk.chars(), expected_chars);
771
772 for _ in 0..10 {
773 let mut start = rng.random_range(0..=chunk.text.len());
774 let mut end = rng.random_range(start..=chunk.text.len());
775 while !chunk.text.is_char_boundary(start) {
776 start -= 1;
777 }
778 while !chunk.text.is_char_boundary(end) {
779 end -= 1;
780 }
781 let range = start..end;
782 log::info!("Range: {:?}", range);
783 let text_slice = &text[range.clone()];
784 let chunk_slice = chunk.slice(range);
785 verify_chunk(chunk_slice, text_slice);
786 }
787 }
788
789 #[gpui::test(iterations = 100)]
790 fn test_split_chunk_slice(mut rng: StdRng) {
791 let text = &random_string_with_utf8_len(&mut rng, MAX_BASE);
792 let chunk = Chunk::new(text);
793 let offset = char_offsets_with_end(text)
794 .into_iter()
795 .choose(&mut rng)
796 .unwrap();
797 let (a, b) = chunk.as_slice().split_at(offset);
798 let (a_str, b_str) = text.split_at(offset);
799 verify_chunk(a, a_str);
800 verify_chunk(b, b_str);
801 }
802
803 #[gpui::test(iterations = 1000)]
804 fn test_nth_set_bit_random(mut rng: StdRng) {
805 let set_count = rng.random_range(0..=128);
806 let mut set_bits = (0..128).choose_multiple(&mut rng, set_count);
807 set_bits.sort();
808 let mut n = 0;
809 for ix in set_bits.iter().copied() {
810 n |= 1 << ix;
811 }
812
813 for (mut ix, position) in set_bits.into_iter().enumerate() {
814 ix += 1;
815 assert_eq!(
816 nth_set_bit(n, ix),
817 position,
818 "nth_set_bit({:0128b}, {})",
819 n,
820 ix
821 );
822 }
823 }
824
825 /// Returns a (biased) random string whose UTF-8 length is no more than `len`.
826 fn random_string_with_utf8_len(rng: &mut StdRng, len: usize) -> String {
827 let mut str = String::new();
828 let mut chars = RandomCharIter::new(rng);
829 loop {
830 let ch = chars.next().unwrap();
831 if str.len() + ch.len_utf8() > len {
832 break;
833 }
834 str.push(ch);
835 }
836 str
837 }
838
839 #[gpui::test(iterations = 1000)]
840 fn test_append_random_strings(mut rng: StdRng) {
841 let len1 = rng.random_range(0..=MAX_BASE);
842 let len2 = rng.random_range(0..=MAX_BASE).saturating_sub(len1);
843 let str1 = random_string_with_utf8_len(&mut rng, len1);
844 let str2 = random_string_with_utf8_len(&mut rng, len2);
845 let mut chunk1 = Chunk::new(&str1);
846 let chunk2 = Chunk::new(&str2);
847 let char_offsets = char_offsets_with_end(&str2);
848 let start_index = rng.random_range(0..char_offsets.len());
849 let start_offset = char_offsets[start_index];
850 let end_offset = char_offsets[rng.random_range(start_index..char_offsets.len())];
851 chunk1.append(chunk2.slice(start_offset..end_offset));
852 verify_chunk(chunk1.as_slice(), &(str1 + &str2[start_offset..end_offset]));
853 }
854
855 /// Return the byte offsets for each character in a string.
856 ///
857 /// These are valid offsets to split the string.
858 fn char_offsets(text: &str) -> Vec<usize> {
859 text.char_indices().map(|(i, _c)| i).collect()
860 }
861
862 /// Return the byte offsets for each character in a string, plus the offset
863 /// past the end of the string.
864 fn char_offsets_with_end(text: &str) -> Vec<usize> {
865 let mut v = char_offsets(text);
866 v.push(text.len());
867 v
868 }
869
870 fn verify_chunk(chunk: ChunkSlice<'_>, text: &str) {
871 let mut offset = 0;
872 let mut offset_utf16 = OffsetUtf16(0);
873 let mut point = Point::zero();
874 let mut point_utf16 = PointUtf16::zero();
875
876 log::info!("Verifying chunk {:?}", text);
877 assert_eq!(chunk.offset_to_point(0), Point::zero());
878
879 let mut expected_tab_positions = Vec::new();
880
881 for (char_offset, c) in text.chars().enumerate() {
882 let expected_point = chunk.offset_to_point(offset);
883 assert_eq!(point, expected_point, "mismatch at offset {}", offset);
884 assert_eq!(
885 chunk.point_to_offset(point),
886 offset,
887 "mismatch at point {:?}",
888 point
889 );
890 assert_eq!(
891 chunk.offset_to_offset_utf16(offset),
892 offset_utf16,
893 "mismatch at offset {}",
894 offset
895 );
896 assert_eq!(
897 chunk.offset_utf16_to_offset(offset_utf16),
898 offset,
899 "mismatch at offset_utf16 {:?}",
900 offset_utf16
901 );
902 assert_eq!(
903 chunk.point_to_point_utf16(point),
904 point_utf16,
905 "mismatch at point {:?}",
906 point
907 );
908 assert_eq!(
909 chunk.point_utf16_to_offset(point_utf16, false),
910 offset,
911 "mismatch at point_utf16 {:?}",
912 point_utf16
913 );
914 assert_eq!(
915 chunk.unclipped_point_utf16_to_point(Unclipped(point_utf16)),
916 point,
917 "mismatch for unclipped_point_utf16_to_point at {:?}",
918 point_utf16
919 );
920
921 assert_eq!(
922 chunk.clip_point(point, Bias::Left),
923 point,
924 "incorrect left clip at {:?}",
925 point
926 );
927 assert_eq!(
928 chunk.clip_point(point, Bias::Right),
929 point,
930 "incorrect right clip at {:?}",
931 point
932 );
933
934 for i in 1..c.len_utf8() {
935 let test_point = Point::new(point.row, point.column + i as u32);
936 assert_eq!(
937 chunk.clip_point(test_point, Bias::Left),
938 point,
939 "incorrect left clip within multi-byte char at {:?}",
940 test_point
941 );
942 assert_eq!(
943 chunk.clip_point(test_point, Bias::Right),
944 Point::new(point.row, point.column + c.len_utf8() as u32),
945 "incorrect right clip within multi-byte char at {:?}",
946 test_point
947 );
948 }
949
950 for i in 1..c.len_utf16() {
951 let test_point = Unclipped(PointUtf16::new(
952 point_utf16.row,
953 point_utf16.column + i as u32,
954 ));
955 assert_eq!(
956 chunk.unclipped_point_utf16_to_point(test_point),
957 point,
958 "incorrect unclipped_point_utf16_to_point within multi-byte char at {:?}",
959 test_point
960 );
961 assert_eq!(
962 chunk.clip_point_utf16(test_point, Bias::Left),
963 point_utf16,
964 "incorrect left clip_point_utf16 within multi-byte char at {:?}",
965 test_point
966 );
967 assert_eq!(
968 chunk.clip_point_utf16(test_point, Bias::Right),
969 PointUtf16::new(point_utf16.row, point_utf16.column + c.len_utf16() as u32),
970 "incorrect right clip_point_utf16 within multi-byte char at {:?}",
971 test_point
972 );
973
974 let test_offset = OffsetUtf16(offset_utf16.0 + i);
975 assert_eq!(
976 chunk.clip_offset_utf16(test_offset, Bias::Left),
977 offset_utf16,
978 "incorrect left clip_offset_utf16 within multi-byte char at {:?}",
979 test_offset
980 );
981 assert_eq!(
982 chunk.clip_offset_utf16(test_offset, Bias::Right),
983 OffsetUtf16(offset_utf16.0 + c.len_utf16()),
984 "incorrect right clip_offset_utf16 within multi-byte char at {:?}",
985 test_offset
986 );
987 }
988
989 if c == '\n' {
990 point.row += 1;
991 point.column = 0;
992 point_utf16.row += 1;
993 point_utf16.column = 0;
994 } else {
995 point.column += c.len_utf8() as u32;
996 point_utf16.column += c.len_utf16() as u32;
997 }
998
999 if c == '\t' {
1000 expected_tab_positions.push(TabPosition {
1001 byte_offset: offset,
1002 char_offset,
1003 });
1004 }
1005
1006 offset += c.len_utf8();
1007 offset_utf16.0 += c.len_utf16();
1008 }
1009
1010 let final_point = chunk.offset_to_point(offset);
1011 assert_eq!(point, final_point, "mismatch at final offset {}", offset);
1012 assert_eq!(
1013 chunk.point_to_offset(point),
1014 offset,
1015 "mismatch at point {:?}",
1016 point
1017 );
1018 assert_eq!(
1019 chunk.offset_to_offset_utf16(offset),
1020 offset_utf16,
1021 "mismatch at offset {}",
1022 offset
1023 );
1024 assert_eq!(
1025 chunk.offset_utf16_to_offset(offset_utf16),
1026 offset,
1027 "mismatch at offset_utf16 {:?}",
1028 offset_utf16
1029 );
1030 assert_eq!(
1031 chunk.point_to_point_utf16(point),
1032 point_utf16,
1033 "mismatch at final point {:?}",
1034 point
1035 );
1036 assert_eq!(
1037 chunk.point_utf16_to_offset(point_utf16, false),
1038 offset,
1039 "mismatch at final point_utf16 {:?}",
1040 point_utf16
1041 );
1042 assert_eq!(
1043 chunk.unclipped_point_utf16_to_point(Unclipped(point_utf16)),
1044 point,
1045 "mismatch for unclipped_point_utf16_to_point at final point {:?}",
1046 point_utf16
1047 );
1048 assert_eq!(
1049 chunk.clip_point(point, Bias::Left),
1050 point,
1051 "incorrect left clip at final point {:?}",
1052 point
1053 );
1054 assert_eq!(
1055 chunk.clip_point(point, Bias::Right),
1056 point,
1057 "incorrect right clip at final point {:?}",
1058 point
1059 );
1060 assert_eq!(
1061 chunk.clip_point_utf16(Unclipped(point_utf16), Bias::Left),
1062 point_utf16,
1063 "incorrect left clip_point_utf16 at final point {:?}",
1064 point_utf16
1065 );
1066 assert_eq!(
1067 chunk.clip_point_utf16(Unclipped(point_utf16), Bias::Right),
1068 point_utf16,
1069 "incorrect right clip_point_utf16 at final point {:?}",
1070 point_utf16
1071 );
1072 assert_eq!(
1073 chunk.clip_offset_utf16(offset_utf16, Bias::Left),
1074 offset_utf16,
1075 "incorrect left clip_offset_utf16 at final offset {:?}",
1076 offset_utf16
1077 );
1078 assert_eq!(
1079 chunk.clip_offset_utf16(offset_utf16, Bias::Right),
1080 offset_utf16,
1081 "incorrect right clip_offset_utf16 at final offset {:?}",
1082 offset_utf16
1083 );
1084
1085 // Verify length methods
1086 assert_eq!(chunk.len(), text.len());
1087 assert_eq!(
1088 chunk.len_utf16().0,
1089 text.chars().map(|c| c.len_utf16()).sum::<usize>()
1090 );
1091
1092 // Verify line counting
1093 let lines = chunk.lines();
1094 let mut newline_count = 0;
1095 let mut last_line_len = 0;
1096 for c in text.chars() {
1097 if c == '\n' {
1098 newline_count += 1;
1099 last_line_len = 0;
1100 } else {
1101 last_line_len += c.len_utf8() as u32;
1102 }
1103 }
1104 assert_eq!(lines, Point::new(newline_count, last_line_len));
1105
1106 // Verify first/last line chars
1107 if !text.is_empty() {
1108 let first_line = text.split('\n').next().unwrap();
1109 assert_eq!(chunk.first_line_chars(), first_line.chars().count() as u32);
1110
1111 let last_line = text.split('\n').next_back().unwrap();
1112 assert_eq!(chunk.last_line_chars(), last_line.chars().count() as u32);
1113 assert_eq!(
1114 chunk.last_line_len_utf16(),
1115 last_line.chars().map(|c| c.len_utf16() as u32).sum::<u32>()
1116 );
1117 }
1118
1119 // Verify longest row
1120 let (longest_row, longest_chars) = chunk.longest_row(&mut 0);
1121 let mut max_chars = 0;
1122 let mut current_row = 0;
1123 let mut current_chars = 0;
1124 let mut max_row = 0;
1125
1126 for c in text.chars() {
1127 if c == '\n' {
1128 if current_chars > max_chars {
1129 max_chars = current_chars;
1130 max_row = current_row;
1131 }
1132 current_row += 1;
1133 current_chars = 0;
1134 } else {
1135 current_chars += 1;
1136 }
1137 }
1138
1139 if current_chars > max_chars {
1140 max_chars = current_chars;
1141 max_row = current_row;
1142 }
1143
1144 assert_eq!((max_row, max_chars as u32), (longest_row, longest_chars));
1145 assert_eq!(chunk.tabs().collect::<Vec<_>>(), expected_tab_positions);
1146 }
1147}