1mod anchor;
2pub mod locator;
3pub mod operation_queue;
4mod patch;
5mod point;
6mod point_utf16;
7#[cfg(any(test, feature = "test-support"))]
8pub mod random_char_iter;
9pub mod rope;
10mod selection;
11pub mod subscription;
12#[cfg(test)]
13mod tests;
14
15pub use anchor::*;
16use anyhow::Result;
17use clock::ReplicaId;
18use collections::{HashMap, HashSet};
19use locator::Locator;
20use operation_queue::OperationQueue;
21pub use patch::Patch;
22pub use point::*;
23pub use point_utf16::*;
24#[cfg(any(test, feature = "test-support"))]
25pub use random_char_iter::*;
26use rope::TextDimension;
27pub use rope::{Chunks, Rope, TextSummary};
28pub use selection::*;
29use std::{
30 cmp::{self, Ordering},
31 iter::Iterator,
32 ops::{self, Deref, Range, Sub},
33 str,
34 sync::Arc,
35 time::{Duration, Instant},
36};
37pub use subscription::*;
38pub use sum_tree::Bias;
39use sum_tree::{FilterCursor, SumTree};
40
41pub type TransactionId = usize;
42
43pub struct Buffer {
44 snapshot: BufferSnapshot,
45 history: History,
46 deferred_ops: OperationQueue<Operation>,
47 deferred_replicas: HashSet<ReplicaId>,
48 replica_id: ReplicaId,
49 remote_id: u64,
50 local_clock: clock::Local,
51 pub lamport_clock: clock::Lamport,
52 subscriptions: Topic,
53}
54
55#[derive(Clone, Debug)]
56pub struct BufferSnapshot {
57 replica_id: ReplicaId,
58 visible_text: Rope,
59 deleted_text: Rope,
60 undo_map: UndoMap,
61 fragments: SumTree<Fragment>,
62 insertions: SumTree<InsertionFragment>,
63 pub version: clock::Global,
64}
65
66#[derive(Clone, Debug)]
67pub struct Transaction {
68 id: TransactionId,
69 start: clock::Global,
70 end: clock::Global,
71 edits: Vec<clock::Local>,
72 ranges: Vec<Range<FullOffset>>,
73 first_edit_at: Instant,
74 last_edit_at: Instant,
75}
76
77impl Transaction {
78 fn push_edit(&mut self, edit: &EditOperation) {
79 self.edits.push(edit.timestamp.local());
80 self.end.observe(edit.timestamp.local());
81
82 let mut other_ranges = edit.ranges.iter().peekable();
83 let mut new_ranges = Vec::new();
84 let insertion_len = edit.new_text.as_ref().map_or(0, |t| t.len());
85 let mut delta = 0;
86
87 for mut self_range in self.ranges.iter().cloned() {
88 self_range.start += delta;
89 self_range.end += delta;
90
91 while let Some(other_range) = other_ranges.peek() {
92 let mut other_range = (*other_range).clone();
93 other_range.start += delta;
94 other_range.end += delta;
95
96 if other_range.start <= self_range.end {
97 other_ranges.next().unwrap();
98 delta += insertion_len;
99
100 if other_range.end < self_range.start {
101 new_ranges.push(other_range.start..other_range.end + insertion_len);
102 self_range.start += insertion_len;
103 self_range.end += insertion_len;
104 } else {
105 self_range.start = cmp::min(self_range.start, other_range.start);
106 self_range.end = cmp::max(self_range.end, other_range.end) + insertion_len;
107 }
108 } else {
109 break;
110 }
111 }
112
113 new_ranges.push(self_range);
114 }
115
116 for other_range in other_ranges {
117 new_ranges.push(other_range.start + delta..other_range.end + delta + insertion_len);
118 delta += insertion_len;
119 }
120
121 self.ranges = new_ranges;
122 }
123}
124
125#[derive(Clone)]
126pub struct History {
127 // TODO: Turn this into a String or Rope, maybe.
128 pub base_text: Arc<str>,
129 ops: HashMap<clock::Local, EditOperation>,
130 undo_stack: Vec<Transaction>,
131 redo_stack: Vec<Transaction>,
132 transaction_depth: usize,
133 group_interval: Duration,
134 next_transaction_id: TransactionId,
135}
136
137impl History {
138 pub fn new(base_text: Arc<str>) -> Self {
139 Self {
140 base_text,
141 ops: Default::default(),
142 undo_stack: Vec::new(),
143 redo_stack: Vec::new(),
144 transaction_depth: 0,
145 group_interval: Duration::from_millis(300),
146 next_transaction_id: 0,
147 }
148 }
149
150 fn push(&mut self, op: EditOperation) {
151 self.ops.insert(op.timestamp.local(), op);
152 }
153
154 fn start_transaction(&mut self, start: clock::Global, now: Instant) -> Option<TransactionId> {
155 self.transaction_depth += 1;
156 if self.transaction_depth == 1 {
157 let id = self.next_transaction_id;
158 self.next_transaction_id += 1;
159 self.undo_stack.push(Transaction {
160 id,
161 start: start.clone(),
162 end: start,
163 edits: Vec::new(),
164 ranges: Vec::new(),
165 first_edit_at: now,
166 last_edit_at: now,
167 });
168 Some(id)
169 } else {
170 None
171 }
172 }
173
174 fn end_transaction(&mut self, now: Instant) -> Option<&Transaction> {
175 assert_ne!(self.transaction_depth, 0);
176 self.transaction_depth -= 1;
177 if self.transaction_depth == 0 {
178 if self.undo_stack.last().unwrap().ranges.is_empty() {
179 self.undo_stack.pop();
180 None
181 } else {
182 let transaction = self.undo_stack.last_mut().unwrap();
183 transaction.last_edit_at = now;
184 Some(transaction)
185 }
186 } else {
187 None
188 }
189 }
190
191 fn group(&mut self) -> Option<TransactionId> {
192 let mut new_len = self.undo_stack.len();
193 let mut transactions = self.undo_stack.iter_mut();
194
195 if let Some(mut transaction) = transactions.next_back() {
196 while let Some(prev_transaction) = transactions.next_back() {
197 if transaction.first_edit_at - prev_transaction.last_edit_at <= self.group_interval
198 && transaction.start == prev_transaction.end
199 {
200 transaction = prev_transaction;
201 new_len -= 1;
202 } else {
203 break;
204 }
205 }
206 }
207
208 let (transactions_to_keep, transactions_to_merge) = self.undo_stack.split_at_mut(new_len);
209 if let Some(last_transaction) = transactions_to_keep.last_mut() {
210 for transaction in &*transactions_to_merge {
211 for edit_id in &transaction.edits {
212 last_transaction.push_edit(&self.ops[edit_id]);
213 }
214 }
215
216 if let Some(transaction) = transactions_to_merge.last_mut() {
217 last_transaction.last_edit_at = transaction.last_edit_at;
218 last_transaction.end = transaction.end.clone();
219 }
220 }
221
222 self.undo_stack.truncate(new_len);
223 self.undo_stack.last().map(|t| t.id)
224 }
225
226 fn push_undo(&mut self, edit_id: clock::Local) {
227 assert_ne!(self.transaction_depth, 0);
228 let last_transaction = self.undo_stack.last_mut().unwrap();
229 last_transaction.push_edit(&self.ops[&edit_id]);
230 }
231
232 fn pop_undo(&mut self) -> Option<&Transaction> {
233 assert_eq!(self.transaction_depth, 0);
234 if let Some(transaction) = self.undo_stack.pop() {
235 self.redo_stack.push(transaction);
236 self.redo_stack.last()
237 } else {
238 None
239 }
240 }
241
242 fn remove_from_undo(&mut self, transaction_id: TransactionId) -> Option<&Transaction> {
243 assert_eq!(self.transaction_depth, 0);
244 if let Some(transaction_ix) = self.undo_stack.iter().rposition(|t| t.id == transaction_id) {
245 let transaction = self.undo_stack.remove(transaction_ix);
246 self.redo_stack.push(transaction);
247 self.redo_stack.last()
248 } else {
249 None
250 }
251 }
252
253 fn pop_redo(&mut self) -> Option<&Transaction> {
254 assert_eq!(self.transaction_depth, 0);
255 if let Some(transaction) = self.redo_stack.pop() {
256 self.undo_stack.push(transaction);
257 self.undo_stack.last()
258 } else {
259 None
260 }
261 }
262
263 fn remove_from_redo(&mut self, transaction_id: TransactionId) -> Option<&Transaction> {
264 assert_eq!(self.transaction_depth, 0);
265 if let Some(transaction_ix) = self.redo_stack.iter().rposition(|t| t.id == transaction_id) {
266 let transaction = self.redo_stack.remove(transaction_ix);
267 self.undo_stack.push(transaction);
268 self.undo_stack.last()
269 } else {
270 None
271 }
272 }
273}
274
275#[derive(Clone, Default, Debug)]
276struct UndoMap(HashMap<clock::Local, Vec<(clock::Local, u32)>>);
277
278impl UndoMap {
279 fn insert(&mut self, undo: &UndoOperation) {
280 for (edit_id, count) in &undo.counts {
281 self.0.entry(*edit_id).or_default().push((undo.id, *count));
282 }
283 }
284
285 fn is_undone(&self, edit_id: clock::Local) -> bool {
286 self.undo_count(edit_id) % 2 == 1
287 }
288
289 fn was_undone(&self, edit_id: clock::Local, version: &clock::Global) -> bool {
290 let undo_count = self
291 .0
292 .get(&edit_id)
293 .unwrap_or(&Vec::new())
294 .iter()
295 .filter(|(undo_id, _)| version.observed(*undo_id))
296 .map(|(_, undo_count)| *undo_count)
297 .max()
298 .unwrap_or(0);
299 undo_count % 2 == 1
300 }
301
302 fn undo_count(&self, edit_id: clock::Local) -> u32 {
303 self.0
304 .get(&edit_id)
305 .unwrap_or(&Vec::new())
306 .iter()
307 .map(|(_, undo_count)| *undo_count)
308 .max()
309 .unwrap_or(0)
310 }
311}
312
313struct Edits<'a, D: TextDimension, F: FnMut(&FragmentSummary) -> bool> {
314 visible_cursor: rope::Cursor<'a>,
315 deleted_cursor: rope::Cursor<'a>,
316 fragments_cursor: Option<FilterCursor<'a, F, Fragment, FragmentTextSummary>>,
317 undos: &'a UndoMap,
318 since: &'a clock::Global,
319 old_end: D,
320 new_end: D,
321 range: Range<(&'a Locator, usize)>,
322}
323
324#[derive(Clone, Debug, Default, Eq, PartialEq)]
325pub struct Edit<D> {
326 pub old: Range<D>,
327 pub new: Range<D>,
328}
329
330impl<D> Edit<D>
331where
332 D: Sub<D, Output = D> + PartialEq + Copy,
333{
334 pub fn old_len(&self) -> D {
335 self.old.end - self.old.start
336 }
337
338 pub fn new_len(&self) -> D {
339 self.new.end - self.new.start
340 }
341
342 pub fn is_empty(&self) -> bool {
343 self.old.start == self.old.end && self.new.start == self.new.end
344 }
345}
346
347impl<D1, D2> Edit<(D1, D2)> {
348 pub fn flatten(self) -> (Edit<D1>, Edit<D2>) {
349 (
350 Edit {
351 old: self.old.start.0..self.old.end.0,
352 new: self.new.start.0..self.new.end.0,
353 },
354 Edit {
355 old: self.old.start.1..self.old.end.1,
356 new: self.new.start.1..self.new.end.1,
357 },
358 )
359 }
360}
361
362#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
363pub struct InsertionTimestamp {
364 pub replica_id: ReplicaId,
365 pub local: clock::Seq,
366 pub lamport: clock::Seq,
367}
368
369impl InsertionTimestamp {
370 fn local(&self) -> clock::Local {
371 clock::Local {
372 replica_id: self.replica_id,
373 value: self.local,
374 }
375 }
376
377 fn lamport(&self) -> clock::Lamport {
378 clock::Lamport {
379 replica_id: self.replica_id,
380 value: self.lamport,
381 }
382 }
383}
384
385#[derive(Eq, PartialEq, Clone, Debug)]
386pub struct Fragment {
387 pub id: Locator,
388 pub insertion_timestamp: InsertionTimestamp,
389 pub insertion_offset: usize,
390 pub len: usize,
391 pub visible: bool,
392 pub deletions: HashSet<clock::Local>,
393 pub max_undos: clock::Global,
394}
395
396#[derive(Eq, PartialEq, Clone, Debug)]
397pub struct FragmentSummary {
398 text: FragmentTextSummary,
399 max_id: Locator,
400 max_version: clock::Global,
401 min_insertion_version: clock::Global,
402 max_insertion_version: clock::Global,
403}
404
405#[derive(Copy, Default, Clone, Debug, PartialEq, Eq)]
406struct FragmentTextSummary {
407 visible: usize,
408 deleted: usize,
409}
410
411impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FragmentTextSummary {
412 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
413 self.visible += summary.text.visible;
414 self.deleted += summary.text.deleted;
415 }
416}
417
418#[derive(Eq, PartialEq, Clone, Debug)]
419struct InsertionFragment {
420 timestamp: clock::Local,
421 split_offset: usize,
422 fragment_id: Locator,
423}
424
425#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
426struct InsertionFragmentKey {
427 timestamp: clock::Local,
428 split_offset: usize,
429}
430
431#[derive(Clone, Debug, Eq, PartialEq)]
432pub enum Operation {
433 Edit(EditOperation),
434 Undo {
435 undo: UndoOperation,
436 lamport_timestamp: clock::Lamport,
437 },
438}
439
440#[derive(Clone, Debug, Eq, PartialEq)]
441pub struct EditOperation {
442 pub timestamp: InsertionTimestamp,
443 pub version: clock::Global,
444 pub ranges: Vec<Range<FullOffset>>,
445 pub new_text: Option<String>,
446}
447
448#[derive(Clone, Debug, Eq, PartialEq)]
449pub struct UndoOperation {
450 pub id: clock::Local,
451 pub counts: HashMap<clock::Local, u32>,
452 pub ranges: Vec<Range<FullOffset>>,
453 pub version: clock::Global,
454}
455
456impl Buffer {
457 pub fn new(replica_id: u16, remote_id: u64, history: History) -> Buffer {
458 let mut fragments = SumTree::new();
459 let mut insertions = SumTree::new();
460
461 let mut local_clock = clock::Local::new(replica_id);
462 let mut lamport_clock = clock::Lamport::new(replica_id);
463 let mut version = clock::Global::new();
464 let visible_text = Rope::from(history.base_text.as_ref());
465 if visible_text.len() > 0 {
466 let insertion_timestamp = InsertionTimestamp {
467 replica_id: 0,
468 local: 1,
469 lamport: 1,
470 };
471 local_clock.observe(insertion_timestamp.local());
472 lamport_clock.observe(insertion_timestamp.lamport());
473 version.observe(insertion_timestamp.local());
474 let fragment_id = Locator::between(&Locator::min(), &Locator::max());
475 let fragment = Fragment {
476 id: fragment_id,
477 insertion_timestamp,
478 insertion_offset: 0,
479 len: visible_text.len(),
480 visible: true,
481 deletions: Default::default(),
482 max_undos: Default::default(),
483 };
484 insertions.push(InsertionFragment::new(&fragment), &());
485 fragments.push(fragment, &None);
486 }
487
488 Buffer {
489 snapshot: BufferSnapshot {
490 replica_id,
491 visible_text,
492 deleted_text: Rope::new(),
493 fragments,
494 insertions,
495 version,
496 undo_map: Default::default(),
497 },
498 history,
499 deferred_ops: OperationQueue::new(),
500 deferred_replicas: HashSet::default(),
501 replica_id,
502 remote_id,
503 local_clock,
504 lamport_clock,
505 subscriptions: Default::default(),
506 }
507 }
508
509 pub fn from_parts(
510 replica_id: u16,
511 remote_id: u64,
512 visible_text: &str,
513 deleted_text: &str,
514 undo_map: impl Iterator<Item = (clock::Local, Vec<(clock::Local, u32)>)>,
515 fragments: impl ExactSizeIterator<Item = Fragment>,
516 lamport_timestamp: u32,
517 version: clock::Global,
518 ) -> Self {
519 let visible_text = visible_text.into();
520 let deleted_text = deleted_text.into();
521 let fragments = SumTree::from_iter(fragments, &None);
522 let mut insertions = fragments
523 .iter()
524 .map(|fragment| InsertionFragment {
525 timestamp: fragment.insertion_timestamp.local(),
526 split_offset: fragment.insertion_offset,
527 fragment_id: fragment.id.clone(),
528 })
529 .collect::<Vec<_>>();
530 insertions.sort_unstable_by_key(|i| (i.timestamp, i.split_offset));
531 Self {
532 remote_id,
533 replica_id,
534
535 history: History::new("".into()),
536 deferred_ops: OperationQueue::new(),
537 deferred_replicas: Default::default(),
538 local_clock: clock::Local {
539 replica_id,
540 value: version.get(replica_id) + 1,
541 },
542 lamport_clock: clock::Lamport {
543 replica_id,
544 value: lamport_timestamp,
545 },
546 subscriptions: Default::default(),
547 snapshot: BufferSnapshot {
548 replica_id,
549 visible_text,
550 deleted_text,
551 undo_map: UndoMap(undo_map.collect()),
552 fragments,
553 insertions: SumTree::from_iter(insertions, &()),
554 version,
555 },
556 }
557 }
558
559 pub fn version(&self) -> clock::Global {
560 self.version.clone()
561 }
562
563 pub fn snapshot(&self) -> BufferSnapshot {
564 self.snapshot.clone()
565 }
566
567 pub fn replica_id(&self) -> ReplicaId {
568 self.local_clock.replica_id
569 }
570
571 pub fn remote_id(&self) -> u64 {
572 self.remote_id
573 }
574
575 pub fn deferred_ops_len(&self) -> usize {
576 self.deferred_ops.len()
577 }
578
579 pub fn transaction_group_interval(&self) -> Duration {
580 self.history.group_interval
581 }
582
583 pub fn edit<R, I, S, T>(&mut self, ranges: R, new_text: T) -> EditOperation
584 where
585 R: IntoIterator<IntoIter = I>,
586 I: ExactSizeIterator<Item = Range<S>>,
587 S: ToOffset,
588 T: Into<String>,
589 {
590 let new_text = new_text.into();
591 let new_text_len = new_text.len();
592 let new_text = if new_text_len > 0 {
593 Some(new_text)
594 } else {
595 None
596 };
597
598 self.start_transaction();
599 let timestamp = InsertionTimestamp {
600 replica_id: self.replica_id,
601 local: self.local_clock.tick().value,
602 lamport: self.lamport_clock.tick().value,
603 };
604 let edit = self.apply_local_edit(ranges.into_iter(), new_text, timestamp);
605
606 self.history.push(edit.clone());
607 self.history.push_undo(edit.timestamp.local());
608 self.snapshot.version.observe(edit.timestamp.local());
609 self.end_transaction();
610 edit
611 }
612
613 fn apply_local_edit<S: ToOffset>(
614 &mut self,
615 ranges: impl ExactSizeIterator<Item = Range<S>>,
616 new_text: Option<String>,
617 timestamp: InsertionTimestamp,
618 ) -> EditOperation {
619 let mut edits = Patch::default();
620 let mut edit_op = EditOperation {
621 timestamp,
622 version: self.version(),
623 ranges: Vec::with_capacity(ranges.len()),
624 new_text: None,
625 };
626 let mut new_insertions = Vec::new();
627 let mut insertion_offset = 0;
628
629 let mut ranges = ranges
630 .map(|range| range.start.to_offset(&*self)..range.end.to_offset(&*self))
631 .peekable();
632
633 let mut new_ropes =
634 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
635 let mut old_fragments = self.fragments.cursor::<FragmentTextSummary>();
636 let mut new_fragments =
637 old_fragments.slice(&ranges.peek().unwrap().start, Bias::Right, &None);
638 new_ropes.push_tree(new_fragments.summary().text);
639
640 let mut fragment_start = old_fragments.start().visible;
641 for range in ranges {
642 let fragment_end = old_fragments.end(&None).visible;
643
644 // If the current fragment ends before this range, then jump ahead to the first fragment
645 // that extends past the start of this range, reusing any intervening fragments.
646 if fragment_end < range.start {
647 // If the current fragment has been partially consumed, then consume the rest of it
648 // and advance to the next fragment before slicing.
649 if fragment_start > old_fragments.start().visible {
650 if fragment_end > fragment_start {
651 let mut suffix = old_fragments.item().unwrap().clone();
652 suffix.len = fragment_end - fragment_start;
653 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
654 new_insertions.push(InsertionFragment::insert_new(&suffix));
655 new_ropes.push_fragment(&suffix, suffix.visible);
656 new_fragments.push(suffix, &None);
657 }
658 old_fragments.next(&None);
659 }
660
661 let slice = old_fragments.slice(&range.start, Bias::Right, &None);
662 new_ropes.push_tree(slice.summary().text);
663 new_fragments.push_tree(slice, &None);
664 fragment_start = old_fragments.start().visible;
665 }
666
667 let full_range_start = FullOffset(range.start + old_fragments.start().deleted);
668
669 // Preserve any portion of the current fragment that precedes this range.
670 if fragment_start < range.start {
671 let mut prefix = old_fragments.item().unwrap().clone();
672 prefix.len = range.start - fragment_start;
673 prefix.insertion_offset += fragment_start - old_fragments.start().visible;
674 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
675 new_insertions.push(InsertionFragment::insert_new(&prefix));
676 new_ropes.push_fragment(&prefix, prefix.visible);
677 new_fragments.push(prefix, &None);
678 fragment_start = range.start;
679 }
680
681 // Insert the new text before any existing fragments within the range.
682 if let Some(new_text) = new_text.as_deref() {
683 let new_start = new_fragments.summary().text.visible;
684 edits.push(Edit {
685 old: fragment_start..fragment_start,
686 new: new_start..new_start + new_text.len(),
687 });
688 let fragment = Fragment {
689 id: Locator::between(
690 &new_fragments.summary().max_id,
691 old_fragments
692 .item()
693 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
694 ),
695 insertion_timestamp: timestamp,
696 insertion_offset,
697 len: new_text.len(),
698 deletions: Default::default(),
699 max_undos: Default::default(),
700 visible: true,
701 };
702 new_insertions.push(InsertionFragment::insert_new(&fragment));
703 new_ropes.push_str(new_text);
704 new_fragments.push(fragment, &None);
705 insertion_offset += new_text.len();
706 }
707
708 // Advance through every fragment that intersects this range, marking the intersecting
709 // portions as deleted.
710 while fragment_start < range.end {
711 let fragment = old_fragments.item().unwrap();
712 let fragment_end = old_fragments.end(&None).visible;
713 let mut intersection = fragment.clone();
714 let intersection_end = cmp::min(range.end, fragment_end);
715 if fragment.visible {
716 intersection.len = intersection_end - fragment_start;
717 intersection.insertion_offset += fragment_start - old_fragments.start().visible;
718 intersection.id =
719 Locator::between(&new_fragments.summary().max_id, &intersection.id);
720 intersection.deletions.insert(timestamp.local());
721 intersection.visible = false;
722 }
723 if intersection.len > 0 {
724 if fragment.visible && !intersection.visible {
725 let new_start = new_fragments.summary().text.visible;
726 edits.push(Edit {
727 old: fragment_start..intersection_end,
728 new: new_start..new_start,
729 });
730 }
731 new_insertions.push(InsertionFragment::insert_new(&intersection));
732 new_ropes.push_fragment(&intersection, fragment.visible);
733 new_fragments.push(intersection, &None);
734 fragment_start = intersection_end;
735 }
736 if fragment_end <= range.end {
737 old_fragments.next(&None);
738 }
739 }
740
741 let full_range_end = FullOffset(range.end + old_fragments.start().deleted);
742 edit_op.ranges.push(full_range_start..full_range_end);
743 }
744
745 // If the current fragment has been partially consumed, then consume the rest of it
746 // and advance to the next fragment before slicing.
747 if fragment_start > old_fragments.start().visible {
748 let fragment_end = old_fragments.end(&None).visible;
749 if fragment_end > fragment_start {
750 let mut suffix = old_fragments.item().unwrap().clone();
751 suffix.len = fragment_end - fragment_start;
752 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
753 new_insertions.push(InsertionFragment::insert_new(&suffix));
754 new_ropes.push_fragment(&suffix, suffix.visible);
755 new_fragments.push(suffix, &None);
756 }
757 old_fragments.next(&None);
758 }
759
760 let suffix = old_fragments.suffix(&None);
761 new_ropes.push_tree(suffix.summary().text);
762 new_fragments.push_tree(suffix, &None);
763 let (visible_text, deleted_text) = new_ropes.finish();
764 drop(old_fragments);
765
766 self.snapshot.fragments = new_fragments;
767 self.snapshot.insertions.edit(new_insertions, &());
768 self.snapshot.visible_text = visible_text;
769 self.snapshot.deleted_text = deleted_text;
770 self.subscriptions.publish_mut(&edits);
771 edit_op.new_text = new_text;
772 edit_op
773 }
774
775 pub fn apply_ops<I: IntoIterator<Item = Operation>>(&mut self, ops: I) -> Result<()> {
776 let mut deferred_ops = Vec::new();
777 for op in ops {
778 if self.can_apply_op(&op) {
779 self.apply_op(op)?;
780 } else {
781 self.deferred_replicas.insert(op.replica_id());
782 deferred_ops.push(op);
783 }
784 }
785 self.deferred_ops.insert(deferred_ops);
786 self.flush_deferred_ops()?;
787 Ok(())
788 }
789
790 fn apply_op(&mut self, op: Operation) -> Result<()> {
791 match op {
792 Operation::Edit(edit) => {
793 if !self.version.observed(edit.timestamp.local()) {
794 self.apply_remote_edit(
795 &edit.version,
796 &edit.ranges,
797 edit.new_text.as_deref(),
798 edit.timestamp,
799 );
800 self.snapshot.version.observe(edit.timestamp.local());
801 self.history.push(edit);
802 }
803 }
804 Operation::Undo {
805 undo,
806 lamport_timestamp,
807 } => {
808 if !self.version.observed(undo.id) {
809 self.apply_undo(&undo)?;
810 self.snapshot.version.observe(undo.id);
811 self.lamport_clock.observe(lamport_timestamp);
812 }
813 }
814 }
815 Ok(())
816 }
817
818 fn apply_remote_edit(
819 &mut self,
820 version: &clock::Global,
821 ranges: &[Range<FullOffset>],
822 new_text: Option<&str>,
823 timestamp: InsertionTimestamp,
824 ) {
825 if ranges.is_empty() {
826 return;
827 }
828
829 let mut edits = Patch::default();
830 let cx = Some(version.clone());
831 let mut new_insertions = Vec::new();
832 let mut insertion_offset = 0;
833 let mut new_ropes =
834 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
835 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
836 let mut new_fragments = old_fragments.slice(
837 &VersionedFullOffset::Offset(ranges[0].start),
838 Bias::Left,
839 &cx,
840 );
841 new_ropes.push_tree(new_fragments.summary().text);
842
843 let mut fragment_start = old_fragments.start().0.full_offset();
844 for range in ranges {
845 let fragment_end = old_fragments.end(&cx).0.full_offset();
846
847 // If the current fragment ends before this range, then jump ahead to the first fragment
848 // that extends past the start of this range, reusing any intervening fragments.
849 if fragment_end < range.start {
850 // If the current fragment has been partially consumed, then consume the rest of it
851 // and advance to the next fragment before slicing.
852 if fragment_start > old_fragments.start().0.full_offset() {
853 if fragment_end > fragment_start {
854 let mut suffix = old_fragments.item().unwrap().clone();
855 suffix.len = fragment_end.0 - fragment_start.0;
856 suffix.insertion_offset +=
857 fragment_start - old_fragments.start().0.full_offset();
858 new_insertions.push(InsertionFragment::insert_new(&suffix));
859 new_ropes.push_fragment(&suffix, suffix.visible);
860 new_fragments.push(suffix, &None);
861 }
862 old_fragments.next(&cx);
863 }
864
865 let slice =
866 old_fragments.slice(&VersionedFullOffset::Offset(range.start), Bias::Left, &cx);
867 new_ropes.push_tree(slice.summary().text);
868 new_fragments.push_tree(slice, &None);
869 fragment_start = old_fragments.start().0.full_offset();
870 }
871
872 // If we are at the end of a non-concurrent fragment, advance to the next one.
873 let fragment_end = old_fragments.end(&cx).0.full_offset();
874 if fragment_end == range.start && fragment_end > fragment_start {
875 let mut fragment = old_fragments.item().unwrap().clone();
876 fragment.len = fragment_end.0 - fragment_start.0;
877 fragment.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
878 new_insertions.push(InsertionFragment::insert_new(&fragment));
879 new_ropes.push_fragment(&fragment, fragment.visible);
880 new_fragments.push(fragment, &None);
881 old_fragments.next(&cx);
882 fragment_start = old_fragments.start().0.full_offset();
883 }
884
885 // Skip over insertions that are concurrent to this edit, but have a lower lamport
886 // timestamp.
887 while let Some(fragment) = old_fragments.item() {
888 if fragment_start == range.start
889 && fragment.insertion_timestamp.lamport() > timestamp.lamport()
890 {
891 new_ropes.push_fragment(fragment, fragment.visible);
892 new_fragments.push(fragment.clone(), &None);
893 old_fragments.next(&cx);
894 debug_assert_eq!(fragment_start, range.start);
895 } else {
896 break;
897 }
898 }
899 debug_assert!(fragment_start <= range.start);
900
901 // Preserve any portion of the current fragment that precedes this range.
902 if fragment_start < range.start {
903 let mut prefix = old_fragments.item().unwrap().clone();
904 prefix.len = range.start.0 - fragment_start.0;
905 prefix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
906 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
907 new_insertions.push(InsertionFragment::insert_new(&prefix));
908 fragment_start = range.start;
909 new_ropes.push_fragment(&prefix, prefix.visible);
910 new_fragments.push(prefix, &None);
911 }
912
913 // Insert the new text before any existing fragments within the range.
914 if let Some(new_text) = new_text {
915 let mut old_start = old_fragments.start().1;
916 if old_fragments.item().map_or(false, |f| f.visible) {
917 old_start += fragment_start.0 - old_fragments.start().0.full_offset().0;
918 }
919 let new_start = new_fragments.summary().text.visible;
920 edits.push(Edit {
921 old: old_start..old_start,
922 new: new_start..new_start + new_text.len(),
923 });
924 let fragment = Fragment {
925 id: Locator::between(
926 &new_fragments.summary().max_id,
927 old_fragments
928 .item()
929 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
930 ),
931 insertion_timestamp: timestamp,
932 insertion_offset,
933 len: new_text.len(),
934 deletions: Default::default(),
935 max_undos: Default::default(),
936 visible: true,
937 };
938 new_insertions.push(InsertionFragment::insert_new(&fragment));
939 new_ropes.push_str(new_text);
940 new_fragments.push(fragment, &None);
941 insertion_offset += new_text.len();
942 }
943
944 // Advance through every fragment that intersects this range, marking the intersecting
945 // portions as deleted.
946 while fragment_start < range.end {
947 let fragment = old_fragments.item().unwrap();
948 let fragment_end = old_fragments.end(&cx).0.full_offset();
949 let mut intersection = fragment.clone();
950 let intersection_end = cmp::min(range.end, fragment_end);
951 if fragment.was_visible(version, &self.undo_map) {
952 intersection.len = intersection_end.0 - fragment_start.0;
953 intersection.insertion_offset +=
954 fragment_start - old_fragments.start().0.full_offset();
955 intersection.id =
956 Locator::between(&new_fragments.summary().max_id, &intersection.id);
957 intersection.deletions.insert(timestamp.local());
958 intersection.visible = false;
959 }
960 if intersection.len > 0 {
961 if fragment.visible && !intersection.visible {
962 let old_start = old_fragments.start().1
963 + (fragment_start.0 - old_fragments.start().0.full_offset().0);
964 let new_start = new_fragments.summary().text.visible;
965 edits.push(Edit {
966 old: old_start..old_start + intersection.len,
967 new: new_start..new_start,
968 });
969 }
970 new_insertions.push(InsertionFragment::insert_new(&intersection));
971 new_ropes.push_fragment(&intersection, fragment.visible);
972 new_fragments.push(intersection, &None);
973 fragment_start = intersection_end;
974 }
975 if fragment_end <= range.end {
976 old_fragments.next(&cx);
977 }
978 }
979 }
980
981 // If the current fragment has been partially consumed, then consume the rest of it
982 // and advance to the next fragment before slicing.
983 if fragment_start > old_fragments.start().0.full_offset() {
984 let fragment_end = old_fragments.end(&cx).0.full_offset();
985 if fragment_end > fragment_start {
986 let mut suffix = old_fragments.item().unwrap().clone();
987 suffix.len = fragment_end.0 - fragment_start.0;
988 suffix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
989 new_insertions.push(InsertionFragment::insert_new(&suffix));
990 new_ropes.push_fragment(&suffix, suffix.visible);
991 new_fragments.push(suffix, &None);
992 }
993 old_fragments.next(&cx);
994 }
995
996 let suffix = old_fragments.suffix(&cx);
997 new_ropes.push_tree(suffix.summary().text);
998 new_fragments.push_tree(suffix, &None);
999 let (visible_text, deleted_text) = new_ropes.finish();
1000 drop(old_fragments);
1001
1002 self.snapshot.fragments = new_fragments;
1003 self.snapshot.visible_text = visible_text;
1004 self.snapshot.deleted_text = deleted_text;
1005 self.snapshot.insertions.edit(new_insertions, &());
1006 self.local_clock.observe(timestamp.local());
1007 self.lamport_clock.observe(timestamp.lamport());
1008 self.subscriptions.publish_mut(&edits);
1009 }
1010
1011 fn apply_undo(&mut self, undo: &UndoOperation) -> Result<()> {
1012 let mut edits = Patch::default();
1013 self.snapshot.undo_map.insert(undo);
1014
1015 let mut cx = undo.version.clone();
1016 for edit_id in undo.counts.keys().copied() {
1017 cx.observe(edit_id);
1018 }
1019 let cx = Some(cx);
1020
1021 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
1022 let mut new_fragments = old_fragments.slice(
1023 &VersionedFullOffset::Offset(undo.ranges[0].start),
1024 Bias::Right,
1025 &cx,
1026 );
1027 let mut new_ropes =
1028 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
1029 new_ropes.push_tree(new_fragments.summary().text);
1030
1031 for range in &undo.ranges {
1032 let mut end_offset = old_fragments.end(&cx).0.full_offset();
1033
1034 if end_offset < range.start {
1035 let preceding_fragments = old_fragments.slice(
1036 &VersionedFullOffset::Offset(range.start),
1037 Bias::Right,
1038 &cx,
1039 );
1040 new_ropes.push_tree(preceding_fragments.summary().text);
1041 new_fragments.push_tree(preceding_fragments, &None);
1042 }
1043
1044 while end_offset <= range.end {
1045 if let Some(fragment) = old_fragments.item() {
1046 let mut fragment = fragment.clone();
1047 let fragment_was_visible = fragment.visible;
1048
1049 if fragment.was_visible(&undo.version, &self.undo_map)
1050 || undo
1051 .counts
1052 .contains_key(&fragment.insertion_timestamp.local())
1053 {
1054 fragment.visible = fragment.is_visible(&self.undo_map);
1055 fragment.max_undos.observe(undo.id);
1056 }
1057
1058 let old_start = old_fragments.start().1;
1059 let new_start = new_fragments.summary().text.visible;
1060 if fragment_was_visible && !fragment.visible {
1061 edits.push(Edit {
1062 old: old_start..old_start + fragment.len,
1063 new: new_start..new_start,
1064 });
1065 } else if !fragment_was_visible && fragment.visible {
1066 edits.push(Edit {
1067 old: old_start..old_start,
1068 new: new_start..new_start + fragment.len,
1069 });
1070 }
1071 new_ropes.push_fragment(&fragment, fragment_was_visible);
1072 new_fragments.push(fragment, &None);
1073
1074 old_fragments.next(&cx);
1075 if end_offset == old_fragments.end(&cx).0.full_offset() {
1076 let unseen_fragments = old_fragments.slice(
1077 &VersionedFullOffset::Offset(end_offset),
1078 Bias::Right,
1079 &cx,
1080 );
1081 new_ropes.push_tree(unseen_fragments.summary().text);
1082 new_fragments.push_tree(unseen_fragments, &None);
1083 }
1084 end_offset = old_fragments.end(&cx).0.full_offset();
1085 } else {
1086 break;
1087 }
1088 }
1089 }
1090
1091 let suffix = old_fragments.suffix(&cx);
1092 new_ropes.push_tree(suffix.summary().text);
1093 new_fragments.push_tree(suffix, &None);
1094
1095 drop(old_fragments);
1096 let (visible_text, deleted_text) = new_ropes.finish();
1097 self.snapshot.fragments = new_fragments;
1098 self.snapshot.visible_text = visible_text;
1099 self.snapshot.deleted_text = deleted_text;
1100 self.subscriptions.publish_mut(&edits);
1101 Ok(())
1102 }
1103
1104 pub fn deferred_ops(&self) -> impl Iterator<Item = &Operation> {
1105 self.deferred_ops.iter()
1106 }
1107
1108 fn flush_deferred_ops(&mut self) -> Result<()> {
1109 self.deferred_replicas.clear();
1110 let mut deferred_ops = Vec::new();
1111 for op in self.deferred_ops.drain().iter().cloned() {
1112 if self.can_apply_op(&op) {
1113 self.apply_op(op)?;
1114 } else {
1115 self.deferred_replicas.insert(op.replica_id());
1116 deferred_ops.push(op);
1117 }
1118 }
1119 self.deferred_ops.insert(deferred_ops);
1120 Ok(())
1121 }
1122
1123 fn can_apply_op(&self, op: &Operation) -> bool {
1124 if self.deferred_replicas.contains(&op.replica_id()) {
1125 false
1126 } else {
1127 match op {
1128 Operation::Edit(edit) => self.version.ge(&edit.version),
1129 Operation::Undo { undo, .. } => self.version.ge(&undo.version),
1130 }
1131 }
1132 }
1133
1134 pub fn can_resolve(&self, anchor: &Anchor) -> bool {
1135 *anchor == Anchor::min()
1136 || *anchor == Anchor::max()
1137 || self.version.observed(anchor.timestamp)
1138 }
1139
1140 pub fn peek_undo_stack(&self) -> Option<&Transaction> {
1141 self.history.undo_stack.last()
1142 }
1143
1144 pub fn start_transaction(&mut self) -> Option<TransactionId> {
1145 self.start_transaction_at(Instant::now())
1146 }
1147
1148 pub fn start_transaction_at(&mut self, now: Instant) -> Option<TransactionId> {
1149 self.history.start_transaction(self.version.clone(), now)
1150 }
1151
1152 pub fn end_transaction(&mut self) -> Option<(TransactionId, clock::Global)> {
1153 self.end_transaction_at(Instant::now())
1154 }
1155
1156 pub fn end_transaction_at(&mut self, now: Instant) -> Option<(TransactionId, clock::Global)> {
1157 if let Some(transaction) = self.history.end_transaction(now) {
1158 let since = transaction.start.clone();
1159 let id = self.history.group().unwrap();
1160 Some((id, since))
1161 } else {
1162 None
1163 }
1164 }
1165
1166 pub fn base_text(&self) -> &Arc<str> {
1167 &self.history.base_text
1168 }
1169
1170 pub fn history(&self) -> impl Iterator<Item = &EditOperation> {
1171 self.history.ops.values()
1172 }
1173
1174 pub fn undo_history(&self) -> impl Iterator<Item = (&clock::Local, &[(clock::Local, u32)])> {
1175 self.undo_map
1176 .0
1177 .iter()
1178 .map(|(edit_id, undo_counts)| (edit_id, undo_counts.as_slice()))
1179 }
1180
1181 pub fn undo(&mut self) -> Option<(TransactionId, Operation)> {
1182 if let Some(transaction) = self.history.pop_undo().cloned() {
1183 let transaction_id = transaction.id;
1184 let op = self.undo_or_redo(transaction).unwrap();
1185 Some((transaction_id, op))
1186 } else {
1187 None
1188 }
1189 }
1190
1191 pub fn undo_transaction(&mut self, transaction_id: TransactionId) -> Option<Operation> {
1192 if let Some(transaction) = self.history.remove_from_undo(transaction_id).cloned() {
1193 let op = self.undo_or_redo(transaction).unwrap();
1194 Some(op)
1195 } else {
1196 None
1197 }
1198 }
1199
1200 pub fn redo(&mut self) -> Option<(TransactionId, Operation)> {
1201 if let Some(transaction) = self.history.pop_redo().cloned() {
1202 let transaction_id = transaction.id;
1203 let op = self.undo_or_redo(transaction).unwrap();
1204 Some((transaction_id, op))
1205 } else {
1206 None
1207 }
1208 }
1209
1210 pub fn redo_transaction(&mut self, transaction_id: TransactionId) -> Option<Operation> {
1211 if let Some(transaction) = self.history.remove_from_redo(transaction_id).cloned() {
1212 let op = self.undo_or_redo(transaction).unwrap();
1213 Some(op)
1214 } else {
1215 None
1216 }
1217 }
1218
1219 fn undo_or_redo(&mut self, transaction: Transaction) -> Result<Operation> {
1220 let mut counts = HashMap::default();
1221 for edit_id in transaction.edits {
1222 counts.insert(edit_id, self.undo_map.undo_count(edit_id) + 1);
1223 }
1224
1225 let undo = UndoOperation {
1226 id: self.local_clock.tick(),
1227 counts,
1228 ranges: transaction.ranges,
1229 version: transaction.start.clone(),
1230 };
1231 self.apply_undo(&undo)?;
1232 self.snapshot.version.observe(undo.id);
1233
1234 Ok(Operation::Undo {
1235 undo,
1236 lamport_timestamp: self.lamport_clock.tick(),
1237 })
1238 }
1239
1240 pub fn subscribe(&mut self) -> Subscription {
1241 self.subscriptions.subscribe()
1242 }
1243}
1244
1245#[cfg(any(test, feature = "test-support"))]
1246impl Buffer {
1247 pub fn set_group_interval(&mut self, group_interval: Duration) {
1248 self.history.group_interval = group_interval;
1249 }
1250
1251 pub fn random_byte_range(
1252 &mut self,
1253 start_offset: usize,
1254 rng: &mut impl rand::Rng,
1255 ) -> Range<usize> {
1256 let end = self.clip_offset(rng.gen_range(start_offset..=self.len()), Bias::Right);
1257 let start = self.clip_offset(rng.gen_range(start_offset..=end), Bias::Right);
1258 start..end
1259 }
1260
1261 pub fn randomly_edit<T>(
1262 &mut self,
1263 rng: &mut T,
1264 old_range_count: usize,
1265 ) -> (Vec<Range<usize>>, String, Operation)
1266 where
1267 T: rand::Rng,
1268 {
1269 let mut old_ranges: Vec<Range<usize>> = Vec::new();
1270 for _ in 0..old_range_count {
1271 let last_end = old_ranges.last().map_or(0, |last_range| last_range.end + 1);
1272 if last_end > self.len() {
1273 break;
1274 }
1275 old_ranges.push(self.random_byte_range(last_end, rng));
1276 }
1277 let new_text_len = rng.gen_range(0..10);
1278 let new_text: String = crate::random_char_iter::RandomCharIter::new(&mut *rng)
1279 .take(new_text_len)
1280 .collect();
1281 log::info!(
1282 "mutating buffer {} at {:?}: {:?}",
1283 self.replica_id,
1284 old_ranges,
1285 new_text
1286 );
1287 let op = self.edit(old_ranges.iter().cloned(), new_text.as_str());
1288 (old_ranges, new_text, Operation::Edit(op))
1289 }
1290
1291 pub fn randomly_undo_redo(&mut self, rng: &mut impl rand::Rng) -> Vec<Operation> {
1292 use rand::prelude::*;
1293
1294 let mut ops = Vec::new();
1295 for _ in 0..rng.gen_range(1..=5) {
1296 if let Some(transaction) = self.history.undo_stack.choose(rng).cloned() {
1297 log::info!(
1298 "undoing buffer {} transaction {:?}",
1299 self.replica_id,
1300 transaction
1301 );
1302 ops.push(self.undo_or_redo(transaction).unwrap());
1303 }
1304 }
1305 ops
1306 }
1307}
1308
1309impl Deref for Buffer {
1310 type Target = BufferSnapshot;
1311
1312 fn deref(&self) -> &Self::Target {
1313 &self.snapshot
1314 }
1315}
1316
1317impl BufferSnapshot {
1318 pub fn as_rope(&self) -> &Rope {
1319 &self.visible_text
1320 }
1321
1322 pub fn replica_id(&self) -> ReplicaId {
1323 self.replica_id
1324 }
1325
1326 pub fn row_count(&self) -> u32 {
1327 self.max_point().row + 1
1328 }
1329
1330 pub fn len(&self) -> usize {
1331 self.visible_text.len()
1332 }
1333
1334 pub fn chars(&self) -> impl Iterator<Item = char> + '_ {
1335 self.chars_at(0)
1336 }
1337
1338 pub fn chars_for_range<T: ToOffset>(&self, range: Range<T>) -> impl Iterator<Item = char> + '_ {
1339 self.text_for_range(range).flat_map(str::chars)
1340 }
1341
1342 pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
1343 where
1344 T: ToOffset,
1345 {
1346 let position = position.to_offset(self);
1347 position == self.clip_offset(position, Bias::Left)
1348 && self
1349 .bytes_in_range(position..self.len())
1350 .flatten()
1351 .copied()
1352 .take(needle.len())
1353 .eq(needle.bytes())
1354 }
1355
1356 pub fn text(&self) -> String {
1357 self.visible_text.to_string()
1358 }
1359
1360 pub fn deleted_text(&self) -> String {
1361 self.deleted_text.to_string()
1362 }
1363
1364 pub fn fragments(&self) -> impl Iterator<Item = &Fragment> {
1365 self.fragments.iter()
1366 }
1367
1368 pub fn text_summary(&self) -> TextSummary {
1369 self.visible_text.summary()
1370 }
1371
1372 pub fn max_point(&self) -> Point {
1373 self.visible_text.max_point()
1374 }
1375
1376 pub fn point_to_offset(&self, point: Point) -> usize {
1377 self.visible_text.point_to_offset(point)
1378 }
1379
1380 pub fn point_utf16_to_offset(&self, point: PointUtf16) -> usize {
1381 self.visible_text.point_utf16_to_offset(point)
1382 }
1383
1384 pub fn point_utf16_to_point(&self, point: PointUtf16) -> Point {
1385 self.visible_text.point_utf16_to_point(point)
1386 }
1387
1388 pub fn offset_to_point(&self, offset: usize) -> Point {
1389 self.visible_text.offset_to_point(offset)
1390 }
1391
1392 pub fn offset_to_point_utf16(&self, offset: usize) -> PointUtf16 {
1393 self.visible_text.offset_to_point_utf16(offset)
1394 }
1395
1396 pub fn version(&self) -> &clock::Global {
1397 &self.version
1398 }
1399
1400 pub fn chars_at<'a, T: ToOffset>(&'a self, position: T) -> impl Iterator<Item = char> + 'a {
1401 let offset = position.to_offset(self);
1402 self.visible_text.chars_at(offset)
1403 }
1404
1405 pub fn reversed_chars_at<'a, T: ToOffset>(
1406 &'a self,
1407 position: T,
1408 ) -> impl Iterator<Item = char> + 'a {
1409 let offset = position.to_offset(self);
1410 self.visible_text.reversed_chars_at(offset)
1411 }
1412
1413 pub fn reversed_chunks_in_range<T: ToOffset>(&self, range: Range<T>) -> rope::Chunks {
1414 let range = range.start.to_offset(self)..range.end.to_offset(self);
1415 self.visible_text.reversed_chunks_in_range(range)
1416 }
1417
1418 pub fn bytes_in_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> rope::Bytes<'a> {
1419 let start = range.start.to_offset(self);
1420 let end = range.end.to_offset(self);
1421 self.visible_text.bytes_in_range(start..end)
1422 }
1423
1424 pub fn text_for_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> Chunks<'a> {
1425 let start = range.start.to_offset(self);
1426 let end = range.end.to_offset(self);
1427 self.visible_text.chunks_in_range(start..end)
1428 }
1429
1430 pub fn line_len(&self, row: u32) -> u32 {
1431 let row_start_offset = Point::new(row, 0).to_offset(self);
1432 let row_end_offset = if row >= self.max_point().row {
1433 self.len()
1434 } else {
1435 Point::new(row + 1, 0).to_offset(self) - 1
1436 };
1437 (row_end_offset - row_start_offset) as u32
1438 }
1439
1440 pub fn is_line_blank(&self, row: u32) -> bool {
1441 self.text_for_range(Point::new(row, 0)..Point::new(row, self.line_len(row)))
1442 .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
1443 }
1444
1445 pub fn indent_column_for_line(&self, row: u32) -> u32 {
1446 let mut result = 0;
1447 for c in self.chars_at(Point::new(row, 0)) {
1448 if c == ' ' {
1449 result += 1;
1450 } else {
1451 break;
1452 }
1453 }
1454 result
1455 }
1456
1457 pub fn text_summary_for_range<'a, D, O: ToOffset>(&'a self, range: Range<O>) -> D
1458 where
1459 D: TextDimension,
1460 {
1461 self.visible_text
1462 .cursor(range.start.to_offset(self))
1463 .summary(range.end.to_offset(self))
1464 }
1465
1466 pub fn summaries_for_anchors<'a, D, A>(&'a self, anchors: A) -> impl 'a + Iterator<Item = D>
1467 where
1468 D: 'a + TextDimension,
1469 A: 'a + IntoIterator<Item = &'a Anchor>,
1470 {
1471 let anchors = anchors.into_iter();
1472 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1473 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1474 let mut text_cursor = self.visible_text.cursor(0);
1475 let mut position = D::default();
1476
1477 anchors.map(move |anchor| {
1478 if *anchor == Anchor::min() {
1479 return D::default();
1480 } else if *anchor == Anchor::max() {
1481 return D::from_text_summary(&self.visible_text.summary());
1482 }
1483
1484 let anchor_key = InsertionFragmentKey {
1485 timestamp: anchor.timestamp,
1486 split_offset: anchor.offset,
1487 };
1488 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1489 if let Some(insertion) = insertion_cursor.item() {
1490 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1491 if comparison == Ordering::Greater
1492 || (anchor.bias == Bias::Left
1493 && comparison == Ordering::Equal
1494 && anchor.offset > 0)
1495 {
1496 insertion_cursor.prev(&());
1497 }
1498 } else {
1499 insertion_cursor.prev(&());
1500 }
1501 let insertion = insertion_cursor.item().expect("invalid insertion");
1502 debug_assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1503
1504 fragment_cursor.seek_forward(&Some(&insertion.fragment_id), Bias::Left, &None);
1505 let fragment = fragment_cursor.item().unwrap();
1506 let mut fragment_offset = fragment_cursor.start().1;
1507 if fragment.visible {
1508 fragment_offset += anchor.offset - insertion.split_offset;
1509 }
1510
1511 position.add_assign(&text_cursor.summary(fragment_offset));
1512 position.clone()
1513 })
1514 }
1515
1516 fn summary_for_anchor<'a, D>(&'a self, anchor: &Anchor) -> D
1517 where
1518 D: TextDimension,
1519 {
1520 if *anchor == Anchor::min() {
1521 D::default()
1522 } else if *anchor == Anchor::max() {
1523 D::from_text_summary(&self.visible_text.summary())
1524 } else {
1525 let anchor_key = InsertionFragmentKey {
1526 timestamp: anchor.timestamp,
1527 split_offset: anchor.offset,
1528 };
1529 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1530 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1531 if let Some(insertion) = insertion_cursor.item() {
1532 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1533 if comparison == Ordering::Greater
1534 || (anchor.bias == Bias::Left
1535 && comparison == Ordering::Equal
1536 && anchor.offset > 0)
1537 {
1538 insertion_cursor.prev(&());
1539 }
1540 } else {
1541 insertion_cursor.prev(&());
1542 }
1543 let insertion = insertion_cursor.item().expect("invalid insertion");
1544 debug_assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1545
1546 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1547 fragment_cursor.seek(&Some(&insertion.fragment_id), Bias::Left, &None);
1548 let fragment = fragment_cursor.item().unwrap();
1549 let mut fragment_offset = fragment_cursor.start().1;
1550 if fragment.visible {
1551 fragment_offset += anchor.offset - insertion.split_offset;
1552 }
1553 self.text_summary_for_range(0..fragment_offset)
1554 }
1555 }
1556
1557 fn fragment_id_for_anchor(&self, anchor: &Anchor) -> &Locator {
1558 if *anchor == Anchor::min() {
1559 &locator::MIN
1560 } else if *anchor == Anchor::max() {
1561 &locator::MAX
1562 } else {
1563 let anchor_key = InsertionFragmentKey {
1564 timestamp: anchor.timestamp,
1565 split_offset: anchor.offset,
1566 };
1567 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1568 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1569 if let Some(insertion) = insertion_cursor.item() {
1570 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1571 if comparison == Ordering::Greater
1572 || (anchor.bias == Bias::Left
1573 && comparison == Ordering::Equal
1574 && anchor.offset > 0)
1575 {
1576 insertion_cursor.prev(&());
1577 }
1578 } else {
1579 insertion_cursor.prev(&());
1580 }
1581 let insertion = insertion_cursor.item().expect("invalid insertion");
1582 debug_assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1583 &insertion.fragment_id
1584 }
1585 }
1586
1587 pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
1588 self.anchor_at(position, Bias::Left)
1589 }
1590
1591 pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
1592 self.anchor_at(position, Bias::Right)
1593 }
1594
1595 pub fn anchor_at<T: ToOffset>(&self, position: T, bias: Bias) -> Anchor {
1596 let offset = position.to_offset(self);
1597 if bias == Bias::Left && offset == 0 {
1598 Anchor::min()
1599 } else if bias == Bias::Right && offset == self.len() {
1600 Anchor::max()
1601 } else {
1602 let mut fragment_cursor = self.fragments.cursor::<usize>();
1603 fragment_cursor.seek(&offset, bias, &None);
1604 let fragment = fragment_cursor.item().unwrap();
1605 let overshoot = offset - *fragment_cursor.start();
1606 Anchor {
1607 timestamp: fragment.insertion_timestamp.local(),
1608 offset: fragment.insertion_offset + overshoot,
1609 bias,
1610 }
1611 }
1612 }
1613
1614 pub fn clip_offset(&self, offset: usize, bias: Bias) -> usize {
1615 self.visible_text.clip_offset(offset, bias)
1616 }
1617
1618 pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
1619 self.visible_text.clip_point(point, bias)
1620 }
1621
1622 pub fn clip_point_utf16(&self, point: PointUtf16, bias: Bias) -> PointUtf16 {
1623 self.visible_text.clip_point_utf16(point, bias)
1624 }
1625
1626 // pub fn point_for_offset(&self, offset: usize) -> Result<Point> {
1627 // if offset <= self.len() {
1628 // Ok(self.text_summary_for_range(0..offset))
1629 // } else {
1630 // Err(anyhow!("offset out of bounds"))
1631 // }
1632 // }
1633
1634 pub fn edits_since<'a, D>(
1635 &'a self,
1636 since: &'a clock::Global,
1637 ) -> impl 'a + Iterator<Item = Edit<D>>
1638 where
1639 D: TextDimension + Ord,
1640 {
1641 self.edits_since_in_range(since, Anchor::min()..Anchor::max())
1642 }
1643
1644 pub fn edits_since_in_range<'a, D>(
1645 &'a self,
1646 since: &'a clock::Global,
1647 range: Range<Anchor>,
1648 ) -> impl 'a + Iterator<Item = Edit<D>>
1649 where
1650 D: TextDimension + Ord,
1651 {
1652 let fragments_cursor = if *since == self.version {
1653 None
1654 } else {
1655 Some(
1656 self.fragments
1657 .filter(move |summary| !since.ge(&summary.max_version), &None),
1658 )
1659 };
1660 let mut cursor = self
1661 .fragments
1662 .cursor::<(Option<&Locator>, FragmentTextSummary)>();
1663
1664 let start_fragment_id = self.fragment_id_for_anchor(&range.start);
1665 cursor.seek(&Some(start_fragment_id), Bias::Left, &None);
1666 let mut visible_start = cursor.start().1.visible;
1667 let mut deleted_start = cursor.start().1.deleted;
1668 if let Some(fragment) = cursor.item() {
1669 let overshoot = range.start.offset - fragment.insertion_offset;
1670 if fragment.visible {
1671 visible_start += overshoot;
1672 } else {
1673 deleted_start += overshoot;
1674 }
1675 }
1676 let end_fragment_id = self.fragment_id_for_anchor(&range.end);
1677
1678 Edits {
1679 visible_cursor: self.visible_text.cursor(visible_start),
1680 deleted_cursor: self.deleted_text.cursor(deleted_start),
1681 fragments_cursor,
1682 undos: &self.undo_map,
1683 since,
1684 old_end: Default::default(),
1685 new_end: Default::default(),
1686 range: (start_fragment_id, range.start.offset)..(end_fragment_id, range.end.offset),
1687 }
1688 }
1689}
1690
1691struct RopeBuilder<'a> {
1692 old_visible_cursor: rope::Cursor<'a>,
1693 old_deleted_cursor: rope::Cursor<'a>,
1694 new_visible: Rope,
1695 new_deleted: Rope,
1696}
1697
1698impl<'a> RopeBuilder<'a> {
1699 fn new(old_visible_cursor: rope::Cursor<'a>, old_deleted_cursor: rope::Cursor<'a>) -> Self {
1700 Self {
1701 old_visible_cursor,
1702 old_deleted_cursor,
1703 new_visible: Rope::new(),
1704 new_deleted: Rope::new(),
1705 }
1706 }
1707
1708 fn push_tree(&mut self, len: FragmentTextSummary) {
1709 self.push(len.visible, true, true);
1710 self.push(len.deleted, false, false);
1711 }
1712
1713 fn push_fragment(&mut self, fragment: &Fragment, was_visible: bool) {
1714 debug_assert!(fragment.len > 0);
1715 self.push(fragment.len, was_visible, fragment.visible)
1716 }
1717
1718 fn push(&mut self, len: usize, was_visible: bool, is_visible: bool) {
1719 let text = if was_visible {
1720 self.old_visible_cursor
1721 .slice(self.old_visible_cursor.offset() + len)
1722 } else {
1723 self.old_deleted_cursor
1724 .slice(self.old_deleted_cursor.offset() + len)
1725 };
1726 if is_visible {
1727 self.new_visible.append(text);
1728 } else {
1729 self.new_deleted.append(text);
1730 }
1731 }
1732
1733 fn push_str(&mut self, text: &str) {
1734 self.new_visible.push(text);
1735 }
1736
1737 fn finish(mut self) -> (Rope, Rope) {
1738 self.new_visible.append(self.old_visible_cursor.suffix());
1739 self.new_deleted.append(self.old_deleted_cursor.suffix());
1740 (self.new_visible, self.new_deleted)
1741 }
1742}
1743
1744impl<'a, D: TextDimension + Ord, F: FnMut(&FragmentSummary) -> bool> Iterator for Edits<'a, D, F> {
1745 type Item = Edit<D>;
1746
1747 fn next(&mut self) -> Option<Self::Item> {
1748 let mut pending_edit: Option<Edit<D>> = None;
1749 let cursor = self.fragments_cursor.as_mut()?;
1750
1751 while let Some(fragment) = cursor.item() {
1752 if fragment.id < *self.range.start.0 {
1753 cursor.next(&None);
1754 continue;
1755 } else if fragment.id > *self.range.end.0 {
1756 break;
1757 }
1758
1759 if cursor.start().visible > self.visible_cursor.offset() {
1760 let summary = self.visible_cursor.summary(cursor.start().visible);
1761 self.old_end.add_assign(&summary);
1762 self.new_end.add_assign(&summary);
1763 }
1764
1765 if pending_edit
1766 .as_ref()
1767 .map_or(false, |change| change.new.end < self.new_end)
1768 {
1769 break;
1770 }
1771
1772 if !fragment.was_visible(&self.since, &self.undos) && fragment.visible {
1773 let mut visible_end = cursor.end(&None).visible;
1774 if fragment.id == *self.range.end.0 {
1775 visible_end = cmp::min(
1776 visible_end,
1777 cursor.start().visible + (self.range.end.1 - fragment.insertion_offset),
1778 );
1779 }
1780
1781 let fragment_summary = self.visible_cursor.summary(visible_end);
1782 let mut new_end = self.new_end.clone();
1783 new_end.add_assign(&fragment_summary);
1784 if let Some(pending_edit) = pending_edit.as_mut() {
1785 pending_edit.new.end = new_end.clone();
1786 } else {
1787 pending_edit = Some(Edit {
1788 old: self.old_end.clone()..self.old_end.clone(),
1789 new: self.new_end.clone()..new_end.clone(),
1790 });
1791 }
1792
1793 self.new_end = new_end;
1794 } else if fragment.was_visible(&self.since, &self.undos) && !fragment.visible {
1795 let mut deleted_end = cursor.end(&None).deleted;
1796 if fragment.id == *self.range.end.0 {
1797 deleted_end = cmp::min(
1798 deleted_end,
1799 cursor.start().deleted + (self.range.end.1 - fragment.insertion_offset),
1800 );
1801 }
1802
1803 if cursor.start().deleted > self.deleted_cursor.offset() {
1804 self.deleted_cursor.seek_forward(cursor.start().deleted);
1805 }
1806 let fragment_summary = self.deleted_cursor.summary(deleted_end);
1807 let mut old_end = self.old_end.clone();
1808 old_end.add_assign(&fragment_summary);
1809 if let Some(pending_edit) = pending_edit.as_mut() {
1810 pending_edit.old.end = old_end.clone();
1811 } else {
1812 pending_edit = Some(Edit {
1813 old: self.old_end.clone()..old_end.clone(),
1814 new: self.new_end.clone()..self.new_end.clone(),
1815 });
1816 }
1817
1818 self.old_end = old_end;
1819 }
1820
1821 cursor.next(&None);
1822 }
1823
1824 pending_edit
1825 }
1826}
1827
1828impl Fragment {
1829 fn is_visible(&self, undos: &UndoMap) -> bool {
1830 !undos.is_undone(self.insertion_timestamp.local())
1831 && self.deletions.iter().all(|d| undos.is_undone(*d))
1832 }
1833
1834 fn was_visible(&self, version: &clock::Global, undos: &UndoMap) -> bool {
1835 (version.observed(self.insertion_timestamp.local())
1836 && !undos.was_undone(self.insertion_timestamp.local(), version))
1837 && self
1838 .deletions
1839 .iter()
1840 .all(|d| !version.observed(*d) || undos.was_undone(*d, version))
1841 }
1842}
1843
1844impl sum_tree::Item for Fragment {
1845 type Summary = FragmentSummary;
1846
1847 fn summary(&self) -> Self::Summary {
1848 let mut max_version = clock::Global::new();
1849 max_version.observe(self.insertion_timestamp.local());
1850 for deletion in &self.deletions {
1851 max_version.observe(*deletion);
1852 }
1853 max_version.join(&self.max_undos);
1854
1855 let mut min_insertion_version = clock::Global::new();
1856 min_insertion_version.observe(self.insertion_timestamp.local());
1857 let max_insertion_version = min_insertion_version.clone();
1858 if self.visible {
1859 FragmentSummary {
1860 max_id: self.id.clone(),
1861 text: FragmentTextSummary {
1862 visible: self.len,
1863 deleted: 0,
1864 },
1865 max_version,
1866 min_insertion_version,
1867 max_insertion_version,
1868 }
1869 } else {
1870 FragmentSummary {
1871 max_id: self.id.clone(),
1872 text: FragmentTextSummary {
1873 visible: 0,
1874 deleted: self.len,
1875 },
1876 max_version,
1877 min_insertion_version,
1878 max_insertion_version,
1879 }
1880 }
1881 }
1882}
1883
1884impl sum_tree::Summary for FragmentSummary {
1885 type Context = Option<clock::Global>;
1886
1887 fn add_summary(&mut self, other: &Self, _: &Self::Context) {
1888 self.max_id.assign(&other.max_id);
1889 self.text.visible += &other.text.visible;
1890 self.text.deleted += &other.text.deleted;
1891 self.max_version.join(&other.max_version);
1892 self.min_insertion_version
1893 .meet(&other.min_insertion_version);
1894 self.max_insertion_version
1895 .join(&other.max_insertion_version);
1896 }
1897}
1898
1899impl Default for FragmentSummary {
1900 fn default() -> Self {
1901 FragmentSummary {
1902 max_id: Locator::min(),
1903 text: FragmentTextSummary::default(),
1904 max_version: clock::Global::new(),
1905 min_insertion_version: clock::Global::new(),
1906 max_insertion_version: clock::Global::new(),
1907 }
1908 }
1909}
1910
1911impl sum_tree::Item for InsertionFragment {
1912 type Summary = InsertionFragmentKey;
1913
1914 fn summary(&self) -> Self::Summary {
1915 InsertionFragmentKey {
1916 timestamp: self.timestamp,
1917 split_offset: self.split_offset,
1918 }
1919 }
1920}
1921
1922impl sum_tree::KeyedItem for InsertionFragment {
1923 type Key = InsertionFragmentKey;
1924
1925 fn key(&self) -> Self::Key {
1926 sum_tree::Item::summary(self)
1927 }
1928}
1929
1930impl InsertionFragment {
1931 fn new(fragment: &Fragment) -> Self {
1932 Self {
1933 timestamp: fragment.insertion_timestamp.local(),
1934 split_offset: fragment.insertion_offset,
1935 fragment_id: fragment.id.clone(),
1936 }
1937 }
1938
1939 fn insert_new(fragment: &Fragment) -> sum_tree::Edit<Self> {
1940 sum_tree::Edit::Insert(Self::new(fragment))
1941 }
1942}
1943
1944impl sum_tree::Summary for InsertionFragmentKey {
1945 type Context = ();
1946
1947 fn add_summary(&mut self, summary: &Self, _: &()) {
1948 *self = *summary;
1949 }
1950}
1951
1952#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
1953pub struct FullOffset(pub usize);
1954
1955impl ops::AddAssign<usize> for FullOffset {
1956 fn add_assign(&mut self, rhs: usize) {
1957 self.0 += rhs;
1958 }
1959}
1960
1961impl ops::Add<usize> for FullOffset {
1962 type Output = Self;
1963
1964 fn add(mut self, rhs: usize) -> Self::Output {
1965 self += rhs;
1966 self
1967 }
1968}
1969
1970impl ops::Sub for FullOffset {
1971 type Output = usize;
1972
1973 fn sub(self, rhs: Self) -> Self::Output {
1974 self.0 - rhs.0
1975 }
1976}
1977
1978impl<'a> sum_tree::Dimension<'a, FragmentSummary> for usize {
1979 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
1980 *self += summary.text.visible;
1981 }
1982}
1983
1984impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FullOffset {
1985 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
1986 self.0 += summary.text.visible + summary.text.deleted;
1987 }
1988}
1989
1990impl<'a> sum_tree::Dimension<'a, FragmentSummary> for Option<&'a Locator> {
1991 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
1992 *self = Some(&summary.max_id);
1993 }
1994}
1995
1996impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, FragmentTextSummary> for usize {
1997 fn cmp(
1998 &self,
1999 cursor_location: &FragmentTextSummary,
2000 _: &Option<clock::Global>,
2001 ) -> cmp::Ordering {
2002 Ord::cmp(self, &cursor_location.visible)
2003 }
2004}
2005
2006#[derive(Copy, Clone, Debug, Eq, PartialEq)]
2007enum VersionedFullOffset {
2008 Offset(FullOffset),
2009 Invalid,
2010}
2011
2012impl VersionedFullOffset {
2013 fn full_offset(&self) -> FullOffset {
2014 if let Self::Offset(position) = self {
2015 *position
2016 } else {
2017 panic!("invalid version")
2018 }
2019 }
2020}
2021
2022impl Default for VersionedFullOffset {
2023 fn default() -> Self {
2024 Self::Offset(Default::default())
2025 }
2026}
2027
2028impl<'a> sum_tree::Dimension<'a, FragmentSummary> for VersionedFullOffset {
2029 fn add_summary(&mut self, summary: &'a FragmentSummary, cx: &Option<clock::Global>) {
2030 if let Self::Offset(offset) = self {
2031 let version = cx.as_ref().unwrap();
2032 if version.ge(&summary.max_insertion_version) {
2033 *offset += summary.text.visible + summary.text.deleted;
2034 } else if version.observed_any(&summary.min_insertion_version) {
2035 *self = Self::Invalid;
2036 }
2037 }
2038 }
2039}
2040
2041impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, Self> for VersionedFullOffset {
2042 fn cmp(&self, cursor_position: &Self, _: &Option<clock::Global>) -> cmp::Ordering {
2043 match (self, cursor_position) {
2044 (Self::Offset(a), Self::Offset(b)) => Ord::cmp(a, b),
2045 (Self::Offset(_), Self::Invalid) => cmp::Ordering::Less,
2046 (Self::Invalid, _) => unreachable!(),
2047 }
2048 }
2049}
2050
2051impl Operation {
2052 fn replica_id(&self) -> ReplicaId {
2053 operation_queue::Operation::lamport_timestamp(self).replica_id
2054 }
2055
2056 pub fn is_edit(&self) -> bool {
2057 match self {
2058 Operation::Edit { .. } => true,
2059 _ => false,
2060 }
2061 }
2062}
2063
2064impl operation_queue::Operation for Operation {
2065 fn lamport_timestamp(&self) -> clock::Lamport {
2066 match self {
2067 Operation::Edit(edit) => edit.timestamp.lamport(),
2068 Operation::Undo {
2069 lamport_timestamp, ..
2070 } => *lamport_timestamp,
2071 }
2072 }
2073}
2074
2075pub trait ToOffset {
2076 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize;
2077}
2078
2079impl ToOffset for Point {
2080 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2081 snapshot.point_to_offset(*self)
2082 }
2083}
2084
2085impl ToOffset for PointUtf16 {
2086 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2087 snapshot.point_utf16_to_offset(*self)
2088 }
2089}
2090
2091impl ToOffset for usize {
2092 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2093 assert!(*self <= snapshot.len(), "offset is out of range");
2094 *self
2095 }
2096}
2097
2098impl ToOffset for Anchor {
2099 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2100 snapshot.summary_for_anchor(self)
2101 }
2102}
2103
2104impl<'a, T: ToOffset> ToOffset for &'a T {
2105 fn to_offset(&self, content: &BufferSnapshot) -> usize {
2106 (*self).to_offset(content)
2107 }
2108}
2109
2110pub trait ToPoint {
2111 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point;
2112}
2113
2114impl ToPoint for Anchor {
2115 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2116 snapshot.summary_for_anchor(self)
2117 }
2118}
2119
2120impl ToPoint for usize {
2121 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2122 snapshot.offset_to_point(*self)
2123 }
2124}
2125
2126impl ToPoint for PointUtf16 {
2127 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2128 snapshot.point_utf16_to_point(*self)
2129 }
2130}
2131
2132impl ToPoint for Point {
2133 fn to_point<'a>(&self, _: &BufferSnapshot) -> Point {
2134 *self
2135 }
2136}
2137
2138pub trait Clip {
2139 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self;
2140}
2141
2142impl Clip for usize {
2143 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2144 snapshot.clip_offset(*self, bias)
2145 }
2146}
2147
2148impl Clip for Point {
2149 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2150 snapshot.clip_point(*self, bias)
2151 }
2152}
2153
2154impl Clip for PointUtf16 {
2155 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2156 snapshot.clip_point_utf16(*self, bias)
2157 }
2158}
2159
2160pub trait FromAnchor {
2161 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self;
2162}
2163
2164impl FromAnchor for Point {
2165 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2166 snapshot.summary_for_anchor(anchor)
2167 }
2168}
2169
2170impl FromAnchor for PointUtf16 {
2171 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2172 snapshot.summary_for_anchor(anchor)
2173 }
2174}
2175
2176impl FromAnchor for usize {
2177 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2178 snapshot.summary_for_anchor(anchor)
2179 }
2180}