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::*;
24use postage::{oneshot, prelude::*};
25#[cfg(any(test, feature = "test-support"))]
26pub use random_char_iter::*;
27use rope::TextDimension;
28pub use rope::{Chunks, Rope, TextSummary};
29pub use selection::*;
30use std::{
31 cmp::{self, Ordering},
32 future::Future,
33 iter::Iterator,
34 ops::{self, Deref, Range, Sub},
35 str,
36 sync::Arc,
37 time::{Duration, Instant},
38};
39pub use subscription::*;
40pub use sum_tree::Bias;
41use sum_tree::{FilterCursor, SumTree};
42
43pub type TransactionId = usize;
44
45pub struct Buffer {
46 snapshot: BufferSnapshot,
47 history: History,
48 deferred_ops: OperationQueue<Operation>,
49 deferred_replicas: HashSet<ReplicaId>,
50 replica_id: ReplicaId,
51 remote_id: u64,
52 local_clock: clock::Local,
53 pub lamport_clock: clock::Lamport,
54 subscriptions: Topic,
55 edit_id_resolvers: HashMap<clock::Local, Vec<oneshot::Sender<()>>>,
56}
57
58#[derive(Clone, Debug)]
59pub struct BufferSnapshot {
60 replica_id: ReplicaId,
61 visible_text: Rope,
62 deleted_text: Rope,
63 undo_map: UndoMap,
64 fragments: SumTree<Fragment>,
65 insertions: SumTree<InsertionFragment>,
66 pub version: clock::Global,
67}
68
69#[derive(Clone, Debug)]
70pub struct Transaction {
71 id: TransactionId,
72 start: clock::Global,
73 end: clock::Global,
74 edits: Vec<clock::Local>,
75 ranges: Vec<Range<FullOffset>>,
76 first_edit_at: Instant,
77 last_edit_at: Instant,
78 suppress_grouping: bool,
79}
80
81impl Transaction {
82 fn push_edit(&mut self, edit: &EditOperation) {
83 self.edits.push(edit.timestamp.local());
84 self.end.observe(edit.timestamp.local());
85
86 let mut other_ranges = edit.ranges.iter().peekable();
87 let mut new_ranges = Vec::new();
88 let insertion_len = edit.new_text.as_ref().map_or(0, |t| t.len());
89 let mut delta = 0;
90
91 for mut self_range in self.ranges.iter().cloned() {
92 self_range.start += delta;
93 self_range.end += delta;
94
95 while let Some(other_range) = other_ranges.peek() {
96 let mut other_range = (*other_range).clone();
97 other_range.start += delta;
98 other_range.end += delta;
99
100 if other_range.start <= self_range.end {
101 other_ranges.next().unwrap();
102 delta += insertion_len;
103
104 if other_range.end < self_range.start {
105 new_ranges.push(other_range.start..other_range.end + insertion_len);
106 self_range.start += insertion_len;
107 self_range.end += insertion_len;
108 } else {
109 self_range.start = cmp::min(self_range.start, other_range.start);
110 self_range.end = cmp::max(self_range.end, other_range.end) + insertion_len;
111 }
112 } else {
113 break;
114 }
115 }
116
117 new_ranges.push(self_range);
118 }
119
120 for other_range in other_ranges {
121 new_ranges.push(other_range.start + delta..other_range.end + delta + insertion_len);
122 delta += insertion_len;
123 }
124
125 self.ranges = new_ranges;
126 }
127}
128
129#[derive(Clone)]
130pub struct History {
131 // TODO: Turn this into a String or Rope, maybe.
132 pub base_text: Arc<str>,
133 ops: HashMap<clock::Local, EditOperation>,
134 undo_stack: Vec<Transaction>,
135 redo_stack: Vec<Transaction>,
136 transaction_depth: usize,
137 group_interval: Duration,
138 next_transaction_id: TransactionId,
139}
140
141impl History {
142 pub fn new(base_text: Arc<str>) -> Self {
143 Self {
144 base_text,
145 ops: Default::default(),
146 undo_stack: Vec::new(),
147 redo_stack: Vec::new(),
148 transaction_depth: 0,
149 group_interval: Duration::from_millis(300),
150 next_transaction_id: 0,
151 }
152 }
153
154 fn push(&mut self, op: EditOperation) {
155 self.ops.insert(op.timestamp.local(), op);
156 }
157
158 fn start_transaction(&mut self, start: clock::Global, now: Instant) -> Option<TransactionId> {
159 self.transaction_depth += 1;
160 if self.transaction_depth == 1 {
161 let id = self.next_transaction_id;
162 self.next_transaction_id += 1;
163 self.undo_stack.push(Transaction {
164 id,
165 start: start.clone(),
166 end: start,
167 edits: Vec::new(),
168 ranges: Vec::new(),
169 first_edit_at: now,
170 last_edit_at: now,
171 suppress_grouping: false,
172 });
173 Some(id)
174 } else {
175 None
176 }
177 }
178
179 fn end_transaction(&mut self, now: Instant) -> Option<&Transaction> {
180 assert_ne!(self.transaction_depth, 0);
181 self.transaction_depth -= 1;
182 if self.transaction_depth == 0 {
183 if self.undo_stack.last().unwrap().ranges.is_empty() {
184 self.undo_stack.pop();
185 None
186 } else {
187 let transaction = self.undo_stack.last_mut().unwrap();
188 transaction.last_edit_at = now;
189 Some(transaction)
190 }
191 } else {
192 None
193 }
194 }
195
196 fn group(&mut self) -> Option<TransactionId> {
197 let mut new_len = self.undo_stack.len();
198 let mut transactions = self.undo_stack.iter_mut();
199
200 if let Some(mut transaction) = transactions.next_back() {
201 while let Some(prev_transaction) = transactions.next_back() {
202 if !prev_transaction.suppress_grouping
203 && transaction.first_edit_at - prev_transaction.last_edit_at
204 <= self.group_interval
205 && transaction.start == prev_transaction.end
206 {
207 transaction = prev_transaction;
208 new_len -= 1;
209 } else {
210 break;
211 }
212 }
213 }
214
215 let (transactions_to_keep, transactions_to_merge) = self.undo_stack.split_at_mut(new_len);
216 if let Some(last_transaction) = transactions_to_keep.last_mut() {
217 for transaction in &*transactions_to_merge {
218 for edit_id in &transaction.edits {
219 last_transaction.push_edit(&self.ops[edit_id]);
220 }
221 }
222
223 if let Some(transaction) = transactions_to_merge.last_mut() {
224 last_transaction.last_edit_at = transaction.last_edit_at;
225 last_transaction.end = transaction.end.clone();
226 }
227 }
228
229 self.undo_stack.truncate(new_len);
230 self.undo_stack.last().map(|t| t.id)
231 }
232
233 fn avoid_grouping_next_transaction(&mut self) {
234 if let Some(transaction) = self.undo_stack.last_mut() {
235 transaction.suppress_grouping = true;
236 }
237 }
238
239 fn push_transaction(&mut self, edit_ids: impl IntoIterator<Item = clock::Local>, now: Instant) {
240 assert_eq!(self.transaction_depth, 0);
241 let mut edit_ids = edit_ids.into_iter().peekable();
242
243 if let Some(first_edit_id) = edit_ids.peek() {
244 let version = self.ops[first_edit_id].version.clone();
245 self.start_transaction(version, now);
246 for edit_id in edit_ids {
247 self.push_undo(edit_id);
248 }
249 self.end_transaction(now);
250 }
251 }
252
253 fn push_undo(&mut self, edit_id: clock::Local) {
254 assert_ne!(self.transaction_depth, 0);
255 let last_transaction = self.undo_stack.last_mut().unwrap();
256 last_transaction.push_edit(&self.ops[&edit_id]);
257 }
258
259 fn pop_undo(&mut self) -> Option<&Transaction> {
260 assert_eq!(self.transaction_depth, 0);
261 if let Some(transaction) = self.undo_stack.pop() {
262 self.redo_stack.push(transaction);
263 self.redo_stack.last()
264 } else {
265 None
266 }
267 }
268
269 fn remove_from_undo(&mut self, transaction_id: TransactionId) -> Option<&Transaction> {
270 assert_eq!(self.transaction_depth, 0);
271 if let Some(transaction_ix) = self.undo_stack.iter().rposition(|t| t.id == transaction_id) {
272 let transaction = self.undo_stack.remove(transaction_ix);
273 self.redo_stack.push(transaction);
274 self.redo_stack.last()
275 } else {
276 None
277 }
278 }
279
280 fn forget(&mut self, transaction_id: TransactionId) {
281 assert_eq!(self.transaction_depth, 0);
282 if let Some(transaction_ix) = self.undo_stack.iter().rposition(|t| t.id == transaction_id) {
283 self.undo_stack.remove(transaction_ix);
284 } else if let Some(transaction_ix) =
285 self.redo_stack.iter().rposition(|t| t.id == transaction_id)
286 {
287 self.undo_stack.remove(transaction_ix);
288 }
289 }
290
291 fn pop_redo(&mut self) -> Option<&Transaction> {
292 assert_eq!(self.transaction_depth, 0);
293 if let Some(transaction) = self.redo_stack.pop() {
294 self.undo_stack.push(transaction);
295 self.undo_stack.last()
296 } else {
297 None
298 }
299 }
300
301 fn remove_from_redo(&mut self, transaction_id: TransactionId) -> Option<&Transaction> {
302 assert_eq!(self.transaction_depth, 0);
303 if let Some(transaction_ix) = self.redo_stack.iter().rposition(|t| t.id == transaction_id) {
304 let transaction = self.redo_stack.remove(transaction_ix);
305 self.undo_stack.push(transaction);
306 self.undo_stack.last()
307 } else {
308 None
309 }
310 }
311}
312
313#[derive(Clone, Default, Debug)]
314struct UndoMap(HashMap<clock::Local, Vec<(clock::Local, u32)>>);
315
316impl UndoMap {
317 fn insert(&mut self, undo: &UndoOperation) {
318 for (edit_id, count) in &undo.counts {
319 self.0.entry(*edit_id).or_default().push((undo.id, *count));
320 }
321 }
322
323 fn is_undone(&self, edit_id: clock::Local) -> bool {
324 self.undo_count(edit_id) % 2 == 1
325 }
326
327 fn was_undone(&self, edit_id: clock::Local, version: &clock::Global) -> bool {
328 let undo_count = self
329 .0
330 .get(&edit_id)
331 .unwrap_or(&Vec::new())
332 .iter()
333 .filter(|(undo_id, _)| version.observed(*undo_id))
334 .map(|(_, undo_count)| *undo_count)
335 .max()
336 .unwrap_or(0);
337 undo_count % 2 == 1
338 }
339
340 fn undo_count(&self, edit_id: clock::Local) -> u32 {
341 self.0
342 .get(&edit_id)
343 .unwrap_or(&Vec::new())
344 .iter()
345 .map(|(_, undo_count)| *undo_count)
346 .max()
347 .unwrap_or(0)
348 }
349}
350
351struct Edits<'a, D: TextDimension, F: FnMut(&FragmentSummary) -> bool> {
352 visible_cursor: rope::Cursor<'a>,
353 deleted_cursor: rope::Cursor<'a>,
354 fragments_cursor: Option<FilterCursor<'a, F, Fragment, FragmentTextSummary>>,
355 undos: &'a UndoMap,
356 since: &'a clock::Global,
357 old_end: D,
358 new_end: D,
359 range: Range<(&'a Locator, usize)>,
360}
361
362#[derive(Clone, Debug, Default, Eq, PartialEq)]
363pub struct Edit<D> {
364 pub old: Range<D>,
365 pub new: Range<D>,
366}
367
368impl<D> Edit<D>
369where
370 D: Sub<D, Output = D> + PartialEq + Copy,
371{
372 pub fn old_len(&self) -> D {
373 self.old.end - self.old.start
374 }
375
376 pub fn new_len(&self) -> D {
377 self.new.end - self.new.start
378 }
379
380 pub fn is_empty(&self) -> bool {
381 self.old.start == self.old.end && self.new.start == self.new.end
382 }
383}
384
385impl<D1, D2> Edit<(D1, D2)> {
386 pub fn flatten(self) -> (Edit<D1>, Edit<D2>) {
387 (
388 Edit {
389 old: self.old.start.0..self.old.end.0,
390 new: self.new.start.0..self.new.end.0,
391 },
392 Edit {
393 old: self.old.start.1..self.old.end.1,
394 new: self.new.start.1..self.new.end.1,
395 },
396 )
397 }
398}
399
400#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
401pub struct InsertionTimestamp {
402 pub replica_id: ReplicaId,
403 pub local: clock::Seq,
404 pub lamport: clock::Seq,
405}
406
407impl InsertionTimestamp {
408 pub fn local(&self) -> clock::Local {
409 clock::Local {
410 replica_id: self.replica_id,
411 value: self.local,
412 }
413 }
414
415 pub fn lamport(&self) -> clock::Lamport {
416 clock::Lamport {
417 replica_id: self.replica_id,
418 value: self.lamport,
419 }
420 }
421}
422
423#[derive(Eq, PartialEq, Clone, Debug)]
424pub struct Fragment {
425 pub id: Locator,
426 pub insertion_timestamp: InsertionTimestamp,
427 pub insertion_offset: usize,
428 pub len: usize,
429 pub visible: bool,
430 pub deletions: HashSet<clock::Local>,
431 pub max_undos: clock::Global,
432}
433
434#[derive(Eq, PartialEq, Clone, Debug)]
435pub struct FragmentSummary {
436 text: FragmentTextSummary,
437 max_id: Locator,
438 max_version: clock::Global,
439 min_insertion_version: clock::Global,
440 max_insertion_version: clock::Global,
441}
442
443#[derive(Copy, Default, Clone, Debug, PartialEq, Eq)]
444struct FragmentTextSummary {
445 visible: usize,
446 deleted: usize,
447}
448
449impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FragmentTextSummary {
450 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
451 self.visible += summary.text.visible;
452 self.deleted += summary.text.deleted;
453 }
454}
455
456#[derive(Eq, PartialEq, Clone, Debug)]
457struct InsertionFragment {
458 timestamp: clock::Local,
459 split_offset: usize,
460 fragment_id: Locator,
461}
462
463#[derive(Clone, Copy, Debug, Default, PartialEq, Eq, PartialOrd, Ord)]
464struct InsertionFragmentKey {
465 timestamp: clock::Local,
466 split_offset: usize,
467}
468
469#[derive(Clone, Debug, Eq, PartialEq)]
470pub enum Operation {
471 Edit(EditOperation),
472 Undo {
473 undo: UndoOperation,
474 lamport_timestamp: clock::Lamport,
475 },
476}
477
478#[derive(Clone, Debug, Eq, PartialEq)]
479pub struct EditOperation {
480 pub timestamp: InsertionTimestamp,
481 pub version: clock::Global,
482 pub ranges: Vec<Range<FullOffset>>,
483 pub new_text: Option<String>,
484}
485
486#[derive(Clone, Debug, Eq, PartialEq)]
487pub struct UndoOperation {
488 pub id: clock::Local,
489 pub counts: HashMap<clock::Local, u32>,
490 pub ranges: Vec<Range<FullOffset>>,
491 pub version: clock::Global,
492}
493
494impl Buffer {
495 pub fn new(replica_id: u16, remote_id: u64, history: History) -> Buffer {
496 let mut fragments = SumTree::new();
497 let mut insertions = SumTree::new();
498
499 let mut local_clock = clock::Local::new(replica_id);
500 let mut lamport_clock = clock::Lamport::new(replica_id);
501 let mut version = clock::Global::new();
502 let visible_text = Rope::from(history.base_text.as_ref());
503 if visible_text.len() > 0 {
504 let insertion_timestamp = InsertionTimestamp {
505 replica_id: 0,
506 local: 1,
507 lamport: 1,
508 };
509 local_clock.observe(insertion_timestamp.local());
510 lamport_clock.observe(insertion_timestamp.lamport());
511 version.observe(insertion_timestamp.local());
512 let fragment_id = Locator::between(&Locator::min(), &Locator::max());
513 let fragment = Fragment {
514 id: fragment_id,
515 insertion_timestamp,
516 insertion_offset: 0,
517 len: visible_text.len(),
518 visible: true,
519 deletions: Default::default(),
520 max_undos: Default::default(),
521 };
522 insertions.push(InsertionFragment::new(&fragment), &());
523 fragments.push(fragment, &None);
524 }
525
526 Buffer {
527 snapshot: BufferSnapshot {
528 replica_id,
529 visible_text,
530 deleted_text: Rope::new(),
531 fragments,
532 insertions,
533 version,
534 undo_map: Default::default(),
535 },
536 history,
537 deferred_ops: OperationQueue::new(),
538 deferred_replicas: HashSet::default(),
539 replica_id,
540 remote_id,
541 local_clock,
542 lamport_clock,
543 subscriptions: Default::default(),
544 edit_id_resolvers: Default::default(),
545 }
546 }
547
548 pub fn from_parts(
549 replica_id: u16,
550 remote_id: u64,
551 visible_text: &str,
552 deleted_text: &str,
553 undo_map: impl Iterator<Item = (clock::Local, Vec<(clock::Local, u32)>)>,
554 fragments: impl ExactSizeIterator<Item = Fragment>,
555 lamport_timestamp: u32,
556 version: clock::Global,
557 ) -> Self {
558 let visible_text = visible_text.into();
559 let deleted_text = deleted_text.into();
560 let fragments = SumTree::from_iter(fragments, &None);
561 let mut insertions = fragments
562 .iter()
563 .map(|fragment| InsertionFragment {
564 timestamp: fragment.insertion_timestamp.local(),
565 split_offset: fragment.insertion_offset,
566 fragment_id: fragment.id.clone(),
567 })
568 .collect::<Vec<_>>();
569 insertions.sort_unstable_by_key(|i| (i.timestamp, i.split_offset));
570 Self {
571 remote_id,
572 replica_id,
573
574 history: History::new("".into()),
575 deferred_ops: OperationQueue::new(),
576 deferred_replicas: Default::default(),
577 local_clock: clock::Local {
578 replica_id,
579 value: version.get(replica_id) + 1,
580 },
581 lamport_clock: clock::Lamport {
582 replica_id,
583 value: lamport_timestamp,
584 },
585 subscriptions: Default::default(),
586 edit_id_resolvers: Default::default(),
587 snapshot: BufferSnapshot {
588 replica_id,
589 visible_text,
590 deleted_text,
591 undo_map: UndoMap(undo_map.collect()),
592 fragments,
593 insertions: SumTree::from_iter(insertions, &()),
594 version,
595 },
596 }
597 }
598
599 pub fn version(&self) -> clock::Global {
600 self.version.clone()
601 }
602
603 pub fn snapshot(&self) -> BufferSnapshot {
604 self.snapshot.clone()
605 }
606
607 pub fn replica_id(&self) -> ReplicaId {
608 self.local_clock.replica_id
609 }
610
611 pub fn remote_id(&self) -> u64 {
612 self.remote_id
613 }
614
615 pub fn deferred_ops_len(&self) -> usize {
616 self.deferred_ops.len()
617 }
618
619 pub fn transaction_group_interval(&self) -> Duration {
620 self.history.group_interval
621 }
622
623 pub fn edit<R, I, S, T>(&mut self, ranges: R, new_text: T) -> EditOperation
624 where
625 R: IntoIterator<IntoIter = I>,
626 I: ExactSizeIterator<Item = Range<S>>,
627 S: ToOffset,
628 T: Into<String>,
629 {
630 let new_text = new_text.into();
631 let new_text_len = new_text.len();
632 let new_text = if new_text_len > 0 {
633 Some(new_text)
634 } else {
635 None
636 };
637
638 self.start_transaction();
639 let timestamp = InsertionTimestamp {
640 replica_id: self.replica_id,
641 local: self.local_clock.tick().value,
642 lamport: self.lamport_clock.tick().value,
643 };
644 let edit = self.apply_local_edit(ranges.into_iter(), new_text, timestamp);
645
646 self.history.push(edit.clone());
647 self.history.push_undo(edit.timestamp.local());
648 self.snapshot.version.observe(edit.timestamp.local());
649 self.end_transaction();
650 edit
651 }
652
653 fn apply_local_edit<S: ToOffset>(
654 &mut self,
655 ranges: impl ExactSizeIterator<Item = Range<S>>,
656 new_text: Option<String>,
657 timestamp: InsertionTimestamp,
658 ) -> EditOperation {
659 let mut edits = Patch::default();
660 let mut edit_op = EditOperation {
661 timestamp,
662 version: self.version(),
663 ranges: Vec::with_capacity(ranges.len()),
664 new_text: None,
665 };
666 let mut new_insertions = Vec::new();
667 let mut insertion_offset = 0;
668
669 let mut ranges = ranges
670 .map(|range| range.start.to_offset(&*self)..range.end.to_offset(&*self))
671 .peekable();
672
673 let mut new_ropes =
674 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
675 let mut old_fragments = self.fragments.cursor::<FragmentTextSummary>();
676 let mut new_fragments =
677 old_fragments.slice(&ranges.peek().unwrap().start, Bias::Right, &None);
678 new_ropes.push_tree(new_fragments.summary().text);
679
680 let mut fragment_start = old_fragments.start().visible;
681 for range in ranges {
682 let fragment_end = old_fragments.end(&None).visible;
683
684 // If the current fragment ends before this range, then jump ahead to the first fragment
685 // that extends past the start of this range, reusing any intervening fragments.
686 if fragment_end < range.start {
687 // If the current fragment has been partially consumed, then consume the rest of it
688 // and advance to the next fragment before slicing.
689 if fragment_start > old_fragments.start().visible {
690 if fragment_end > fragment_start {
691 let mut suffix = old_fragments.item().unwrap().clone();
692 suffix.len = fragment_end - fragment_start;
693 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
694 new_insertions.push(InsertionFragment::insert_new(&suffix));
695 new_ropes.push_fragment(&suffix, suffix.visible);
696 new_fragments.push(suffix, &None);
697 }
698 old_fragments.next(&None);
699 }
700
701 let slice = old_fragments.slice(&range.start, Bias::Right, &None);
702 new_ropes.push_tree(slice.summary().text);
703 new_fragments.push_tree(slice, &None);
704 fragment_start = old_fragments.start().visible;
705 }
706
707 let full_range_start = FullOffset(range.start + old_fragments.start().deleted);
708
709 // Preserve any portion of the current fragment that precedes this range.
710 if fragment_start < range.start {
711 let mut prefix = old_fragments.item().unwrap().clone();
712 prefix.len = range.start - fragment_start;
713 prefix.insertion_offset += fragment_start - old_fragments.start().visible;
714 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
715 new_insertions.push(InsertionFragment::insert_new(&prefix));
716 new_ropes.push_fragment(&prefix, prefix.visible);
717 new_fragments.push(prefix, &None);
718 fragment_start = range.start;
719 }
720
721 // Insert the new text before any existing fragments within the range.
722 if let Some(new_text) = new_text.as_deref() {
723 let new_start = new_fragments.summary().text.visible;
724 edits.push(Edit {
725 old: fragment_start..fragment_start,
726 new: new_start..new_start + new_text.len(),
727 });
728 let fragment = Fragment {
729 id: Locator::between(
730 &new_fragments.summary().max_id,
731 old_fragments
732 .item()
733 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
734 ),
735 insertion_timestamp: timestamp,
736 insertion_offset,
737 len: new_text.len(),
738 deletions: Default::default(),
739 max_undos: Default::default(),
740 visible: true,
741 };
742 new_insertions.push(InsertionFragment::insert_new(&fragment));
743 new_ropes.push_str(new_text);
744 new_fragments.push(fragment, &None);
745 insertion_offset += new_text.len();
746 }
747
748 // Advance through every fragment that intersects this range, marking the intersecting
749 // portions as deleted.
750 while fragment_start < range.end {
751 let fragment = old_fragments.item().unwrap();
752 let fragment_end = old_fragments.end(&None).visible;
753 let mut intersection = fragment.clone();
754 let intersection_end = cmp::min(range.end, fragment_end);
755 if fragment.visible {
756 intersection.len = intersection_end - fragment_start;
757 intersection.insertion_offset += fragment_start - old_fragments.start().visible;
758 intersection.id =
759 Locator::between(&new_fragments.summary().max_id, &intersection.id);
760 intersection.deletions.insert(timestamp.local());
761 intersection.visible = false;
762 }
763 if intersection.len > 0 {
764 if fragment.visible && !intersection.visible {
765 let new_start = new_fragments.summary().text.visible;
766 edits.push(Edit {
767 old: fragment_start..intersection_end,
768 new: new_start..new_start,
769 });
770 }
771 new_insertions.push(InsertionFragment::insert_new(&intersection));
772 new_ropes.push_fragment(&intersection, fragment.visible);
773 new_fragments.push(intersection, &None);
774 fragment_start = intersection_end;
775 }
776 if fragment_end <= range.end {
777 old_fragments.next(&None);
778 }
779 }
780
781 let full_range_end = FullOffset(range.end + old_fragments.start().deleted);
782 edit_op.ranges.push(full_range_start..full_range_end);
783 }
784
785 // If the current fragment has been partially consumed, then consume the rest of it
786 // and advance to the next fragment before slicing.
787 if fragment_start > old_fragments.start().visible {
788 let fragment_end = old_fragments.end(&None).visible;
789 if fragment_end > fragment_start {
790 let mut suffix = old_fragments.item().unwrap().clone();
791 suffix.len = fragment_end - fragment_start;
792 suffix.insertion_offset += fragment_start - old_fragments.start().visible;
793 new_insertions.push(InsertionFragment::insert_new(&suffix));
794 new_ropes.push_fragment(&suffix, suffix.visible);
795 new_fragments.push(suffix, &None);
796 }
797 old_fragments.next(&None);
798 }
799
800 let suffix = old_fragments.suffix(&None);
801 new_ropes.push_tree(suffix.summary().text);
802 new_fragments.push_tree(suffix, &None);
803 let (visible_text, deleted_text) = new_ropes.finish();
804 drop(old_fragments);
805
806 self.snapshot.fragments = new_fragments;
807 self.snapshot.insertions.edit(new_insertions, &());
808 self.snapshot.visible_text = visible_text;
809 self.snapshot.deleted_text = deleted_text;
810 self.subscriptions.publish_mut(&edits);
811 edit_op.new_text = new_text;
812 edit_op
813 }
814
815 pub fn apply_ops<I: IntoIterator<Item = Operation>>(&mut self, ops: I) -> Result<()> {
816 let mut deferred_ops = Vec::new();
817 for op in ops {
818 if self.can_apply_op(&op) {
819 self.apply_op(op)?;
820 } else {
821 self.deferred_replicas.insert(op.replica_id());
822 deferred_ops.push(op);
823 }
824 }
825 self.deferred_ops.insert(deferred_ops);
826 self.flush_deferred_ops()?;
827 Ok(())
828 }
829
830 fn apply_op(&mut self, op: Operation) -> Result<()> {
831 match op {
832 Operation::Edit(edit) => {
833 if !self.version.observed(edit.timestamp.local()) {
834 self.apply_remote_edit(
835 &edit.version,
836 &edit.ranges,
837 edit.new_text.as_deref(),
838 edit.timestamp,
839 );
840 self.snapshot.version.observe(edit.timestamp.local());
841 self.resolve_edit(edit.timestamp.local());
842 self.history.push(edit);
843 }
844 }
845 Operation::Undo {
846 undo,
847 lamport_timestamp,
848 } => {
849 if !self.version.observed(undo.id) {
850 self.apply_undo(&undo)?;
851 self.snapshot.version.observe(undo.id);
852 self.lamport_clock.observe(lamport_timestamp);
853 }
854 }
855 }
856 Ok(())
857 }
858
859 fn apply_remote_edit(
860 &mut self,
861 version: &clock::Global,
862 ranges: &[Range<FullOffset>],
863 new_text: Option<&str>,
864 timestamp: InsertionTimestamp,
865 ) {
866 if ranges.is_empty() {
867 return;
868 }
869
870 let mut edits = Patch::default();
871 let cx = Some(version.clone());
872 let mut new_insertions = Vec::new();
873 let mut insertion_offset = 0;
874 let mut new_ropes =
875 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
876 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
877 let mut new_fragments = old_fragments.slice(
878 &VersionedFullOffset::Offset(ranges[0].start),
879 Bias::Left,
880 &cx,
881 );
882 new_ropes.push_tree(new_fragments.summary().text);
883
884 let mut fragment_start = old_fragments.start().0.full_offset();
885 for range in ranges {
886 let fragment_end = old_fragments.end(&cx).0.full_offset();
887
888 // If the current fragment ends before this range, then jump ahead to the first fragment
889 // that extends past the start of this range, reusing any intervening fragments.
890 if fragment_end < range.start {
891 // If the current fragment has been partially consumed, then consume the rest of it
892 // and advance to the next fragment before slicing.
893 if fragment_start > old_fragments.start().0.full_offset() {
894 if fragment_end > fragment_start {
895 let mut suffix = old_fragments.item().unwrap().clone();
896 suffix.len = fragment_end.0 - fragment_start.0;
897 suffix.insertion_offset +=
898 fragment_start - old_fragments.start().0.full_offset();
899 new_insertions.push(InsertionFragment::insert_new(&suffix));
900 new_ropes.push_fragment(&suffix, suffix.visible);
901 new_fragments.push(suffix, &None);
902 }
903 old_fragments.next(&cx);
904 }
905
906 let slice =
907 old_fragments.slice(&VersionedFullOffset::Offset(range.start), Bias::Left, &cx);
908 new_ropes.push_tree(slice.summary().text);
909 new_fragments.push_tree(slice, &None);
910 fragment_start = old_fragments.start().0.full_offset();
911 }
912
913 // If we are at the end of a non-concurrent fragment, advance to the next one.
914 let fragment_end = old_fragments.end(&cx).0.full_offset();
915 if fragment_end == range.start && fragment_end > fragment_start {
916 let mut fragment = old_fragments.item().unwrap().clone();
917 fragment.len = fragment_end.0 - fragment_start.0;
918 fragment.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
919 new_insertions.push(InsertionFragment::insert_new(&fragment));
920 new_ropes.push_fragment(&fragment, fragment.visible);
921 new_fragments.push(fragment, &None);
922 old_fragments.next(&cx);
923 fragment_start = old_fragments.start().0.full_offset();
924 }
925
926 // Skip over insertions that are concurrent to this edit, but have a lower lamport
927 // timestamp.
928 while let Some(fragment) = old_fragments.item() {
929 if fragment_start == range.start
930 && fragment.insertion_timestamp.lamport() > timestamp.lamport()
931 {
932 new_ropes.push_fragment(fragment, fragment.visible);
933 new_fragments.push(fragment.clone(), &None);
934 old_fragments.next(&cx);
935 debug_assert_eq!(fragment_start, range.start);
936 } else {
937 break;
938 }
939 }
940 debug_assert!(fragment_start <= range.start);
941
942 // Preserve any portion of the current fragment that precedes this range.
943 if fragment_start < range.start {
944 let mut prefix = old_fragments.item().unwrap().clone();
945 prefix.len = range.start.0 - fragment_start.0;
946 prefix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
947 prefix.id = Locator::between(&new_fragments.summary().max_id, &prefix.id);
948 new_insertions.push(InsertionFragment::insert_new(&prefix));
949 fragment_start = range.start;
950 new_ropes.push_fragment(&prefix, prefix.visible);
951 new_fragments.push(prefix, &None);
952 }
953
954 // Insert the new text before any existing fragments within the range.
955 if let Some(new_text) = new_text {
956 let mut old_start = old_fragments.start().1;
957 if old_fragments.item().map_or(false, |f| f.visible) {
958 old_start += fragment_start.0 - old_fragments.start().0.full_offset().0;
959 }
960 let new_start = new_fragments.summary().text.visible;
961 edits.push(Edit {
962 old: old_start..old_start,
963 new: new_start..new_start + new_text.len(),
964 });
965 let fragment = Fragment {
966 id: Locator::between(
967 &new_fragments.summary().max_id,
968 old_fragments
969 .item()
970 .map_or(&Locator::max(), |old_fragment| &old_fragment.id),
971 ),
972 insertion_timestamp: timestamp,
973 insertion_offset,
974 len: new_text.len(),
975 deletions: Default::default(),
976 max_undos: Default::default(),
977 visible: true,
978 };
979 new_insertions.push(InsertionFragment::insert_new(&fragment));
980 new_ropes.push_str(new_text);
981 new_fragments.push(fragment, &None);
982 insertion_offset += new_text.len();
983 }
984
985 // Advance through every fragment that intersects this range, marking the intersecting
986 // portions as deleted.
987 while fragment_start < range.end {
988 let fragment = old_fragments.item().unwrap();
989 let fragment_end = old_fragments.end(&cx).0.full_offset();
990 let mut intersection = fragment.clone();
991 let intersection_end = cmp::min(range.end, fragment_end);
992 if fragment.was_visible(version, &self.undo_map) {
993 intersection.len = intersection_end.0 - fragment_start.0;
994 intersection.insertion_offset +=
995 fragment_start - old_fragments.start().0.full_offset();
996 intersection.id =
997 Locator::between(&new_fragments.summary().max_id, &intersection.id);
998 intersection.deletions.insert(timestamp.local());
999 intersection.visible = false;
1000 }
1001 if intersection.len > 0 {
1002 if fragment.visible && !intersection.visible {
1003 let old_start = old_fragments.start().1
1004 + (fragment_start.0 - old_fragments.start().0.full_offset().0);
1005 let new_start = new_fragments.summary().text.visible;
1006 edits.push(Edit {
1007 old: old_start..old_start + intersection.len,
1008 new: new_start..new_start,
1009 });
1010 }
1011 new_insertions.push(InsertionFragment::insert_new(&intersection));
1012 new_ropes.push_fragment(&intersection, fragment.visible);
1013 new_fragments.push(intersection, &None);
1014 fragment_start = intersection_end;
1015 }
1016 if fragment_end <= range.end {
1017 old_fragments.next(&cx);
1018 }
1019 }
1020 }
1021
1022 // If the current fragment has been partially consumed, then consume the rest of it
1023 // and advance to the next fragment before slicing.
1024 if fragment_start > old_fragments.start().0.full_offset() {
1025 let fragment_end = old_fragments.end(&cx).0.full_offset();
1026 if fragment_end > fragment_start {
1027 let mut suffix = old_fragments.item().unwrap().clone();
1028 suffix.len = fragment_end.0 - fragment_start.0;
1029 suffix.insertion_offset += fragment_start - old_fragments.start().0.full_offset();
1030 new_insertions.push(InsertionFragment::insert_new(&suffix));
1031 new_ropes.push_fragment(&suffix, suffix.visible);
1032 new_fragments.push(suffix, &None);
1033 }
1034 old_fragments.next(&cx);
1035 }
1036
1037 let suffix = old_fragments.suffix(&cx);
1038 new_ropes.push_tree(suffix.summary().text);
1039 new_fragments.push_tree(suffix, &None);
1040 let (visible_text, deleted_text) = new_ropes.finish();
1041 drop(old_fragments);
1042
1043 self.snapshot.fragments = new_fragments;
1044 self.snapshot.visible_text = visible_text;
1045 self.snapshot.deleted_text = deleted_text;
1046 self.snapshot.insertions.edit(new_insertions, &());
1047 self.local_clock.observe(timestamp.local());
1048 self.lamport_clock.observe(timestamp.lamport());
1049 self.subscriptions.publish_mut(&edits);
1050 }
1051
1052 fn apply_undo(&mut self, undo: &UndoOperation) -> Result<()> {
1053 let mut edits = Patch::default();
1054 self.snapshot.undo_map.insert(undo);
1055
1056 let mut cx = undo.version.clone();
1057 for edit_id in undo.counts.keys().copied() {
1058 cx.observe(edit_id);
1059 }
1060 let cx = Some(cx);
1061
1062 let mut old_fragments = self.fragments.cursor::<(VersionedFullOffset, usize)>();
1063 let mut new_fragments = old_fragments.slice(
1064 &VersionedFullOffset::Offset(undo.ranges[0].start),
1065 Bias::Right,
1066 &cx,
1067 );
1068 let mut new_ropes =
1069 RopeBuilder::new(self.visible_text.cursor(0), self.deleted_text.cursor(0));
1070 new_ropes.push_tree(new_fragments.summary().text);
1071
1072 for range in &undo.ranges {
1073 let mut end_offset = old_fragments.end(&cx).0.full_offset();
1074
1075 if end_offset < range.start {
1076 let preceding_fragments = old_fragments.slice(
1077 &VersionedFullOffset::Offset(range.start),
1078 Bias::Right,
1079 &cx,
1080 );
1081 new_ropes.push_tree(preceding_fragments.summary().text);
1082 new_fragments.push_tree(preceding_fragments, &None);
1083 }
1084
1085 while end_offset <= range.end {
1086 if let Some(fragment) = old_fragments.item() {
1087 let mut fragment = fragment.clone();
1088 let fragment_was_visible = fragment.visible;
1089
1090 if fragment.was_visible(&undo.version, &self.undo_map)
1091 || undo
1092 .counts
1093 .contains_key(&fragment.insertion_timestamp.local())
1094 {
1095 fragment.visible = fragment.is_visible(&self.undo_map);
1096 fragment.max_undos.observe(undo.id);
1097 }
1098
1099 let old_start = old_fragments.start().1;
1100 let new_start = new_fragments.summary().text.visible;
1101 if fragment_was_visible && !fragment.visible {
1102 edits.push(Edit {
1103 old: old_start..old_start + fragment.len,
1104 new: new_start..new_start,
1105 });
1106 } else if !fragment_was_visible && fragment.visible {
1107 edits.push(Edit {
1108 old: old_start..old_start,
1109 new: new_start..new_start + fragment.len,
1110 });
1111 }
1112 new_ropes.push_fragment(&fragment, fragment_was_visible);
1113 new_fragments.push(fragment, &None);
1114
1115 old_fragments.next(&cx);
1116 if end_offset == old_fragments.end(&cx).0.full_offset() {
1117 let unseen_fragments = old_fragments.slice(
1118 &VersionedFullOffset::Offset(end_offset),
1119 Bias::Right,
1120 &cx,
1121 );
1122 new_ropes.push_tree(unseen_fragments.summary().text);
1123 new_fragments.push_tree(unseen_fragments, &None);
1124 }
1125 end_offset = old_fragments.end(&cx).0.full_offset();
1126 } else {
1127 break;
1128 }
1129 }
1130 }
1131
1132 let suffix = old_fragments.suffix(&cx);
1133 new_ropes.push_tree(suffix.summary().text);
1134 new_fragments.push_tree(suffix, &None);
1135
1136 drop(old_fragments);
1137 let (visible_text, deleted_text) = new_ropes.finish();
1138 self.snapshot.fragments = new_fragments;
1139 self.snapshot.visible_text = visible_text;
1140 self.snapshot.deleted_text = deleted_text;
1141 self.subscriptions.publish_mut(&edits);
1142 Ok(())
1143 }
1144
1145 pub fn deferred_ops(&self) -> impl Iterator<Item = &Operation> {
1146 self.deferred_ops.iter()
1147 }
1148
1149 fn flush_deferred_ops(&mut self) -> Result<()> {
1150 self.deferred_replicas.clear();
1151 let mut deferred_ops = Vec::new();
1152 for op in self.deferred_ops.drain().iter().cloned() {
1153 if self.can_apply_op(&op) {
1154 self.apply_op(op)?;
1155 } else {
1156 self.deferred_replicas.insert(op.replica_id());
1157 deferred_ops.push(op);
1158 }
1159 }
1160 self.deferred_ops.insert(deferred_ops);
1161 Ok(())
1162 }
1163
1164 fn can_apply_op(&self, op: &Operation) -> bool {
1165 if self.deferred_replicas.contains(&op.replica_id()) {
1166 false
1167 } else {
1168 match op {
1169 Operation::Edit(edit) => self.version.observed_all(&edit.version),
1170 Operation::Undo { undo, .. } => self.version.observed_all(&undo.version),
1171 }
1172 }
1173 }
1174
1175 pub fn peek_undo_stack(&self) -> Option<&Transaction> {
1176 self.history.undo_stack.last()
1177 }
1178
1179 pub fn start_transaction(&mut self) -> Option<TransactionId> {
1180 self.start_transaction_at(Instant::now())
1181 }
1182
1183 pub fn start_transaction_at(&mut self, now: Instant) -> Option<TransactionId> {
1184 self.history.start_transaction(self.version.clone(), now)
1185 }
1186
1187 pub fn end_transaction(&mut self) -> Option<(TransactionId, clock::Global)> {
1188 self.end_transaction_at(Instant::now())
1189 }
1190
1191 pub fn end_transaction_at(&mut self, now: Instant) -> Option<(TransactionId, clock::Global)> {
1192 if let Some(transaction) = self.history.end_transaction(now) {
1193 let since = transaction.start.clone();
1194 let id = self.history.group().unwrap();
1195 Some((id, since))
1196 } else {
1197 None
1198 }
1199 }
1200
1201 pub fn avoid_grouping_next_transaction(&mut self) {
1202 self.history.avoid_grouping_next_transaction()
1203 }
1204
1205 pub fn base_text(&self) -> &Arc<str> {
1206 &self.history.base_text
1207 }
1208
1209 pub fn history(&self) -> impl Iterator<Item = &EditOperation> {
1210 self.history.ops.values()
1211 }
1212
1213 pub fn undo_history(&self) -> impl Iterator<Item = (&clock::Local, &[(clock::Local, u32)])> {
1214 self.undo_map
1215 .0
1216 .iter()
1217 .map(|(edit_id, undo_counts)| (edit_id, undo_counts.as_slice()))
1218 }
1219
1220 pub fn undo(&mut self) -> Option<(TransactionId, Operation)> {
1221 if let Some(transaction) = self.history.pop_undo().cloned() {
1222 let transaction_id = transaction.id;
1223 let op = self.undo_or_redo(transaction).unwrap();
1224 Some((transaction_id, op))
1225 } else {
1226 None
1227 }
1228 }
1229
1230 pub fn undo_transaction(&mut self, transaction_id: TransactionId) -> Option<Operation> {
1231 if let Some(transaction) = self.history.remove_from_undo(transaction_id).cloned() {
1232 let op = self.undo_or_redo(transaction).unwrap();
1233 Some(op)
1234 } else {
1235 None
1236 }
1237 }
1238
1239 pub fn forget_transaction(&mut self, transaction_id: TransactionId) {
1240 self.history.forget(transaction_id);
1241 }
1242
1243 pub fn redo(&mut self) -> Option<(TransactionId, Operation)> {
1244 if let Some(transaction) = self.history.pop_redo().cloned() {
1245 let transaction_id = transaction.id;
1246 let op = self.undo_or_redo(transaction).unwrap();
1247 Some((transaction_id, op))
1248 } else {
1249 None
1250 }
1251 }
1252
1253 pub fn redo_transaction(&mut self, transaction_id: TransactionId) -> Option<Operation> {
1254 if let Some(transaction) = self.history.remove_from_redo(transaction_id).cloned() {
1255 let op = self.undo_or_redo(transaction).unwrap();
1256 Some(op)
1257 } else {
1258 None
1259 }
1260 }
1261
1262 fn undo_or_redo(&mut self, transaction: Transaction) -> Result<Operation> {
1263 let mut counts = HashMap::default();
1264 for edit_id in transaction.edits {
1265 counts.insert(edit_id, self.undo_map.undo_count(edit_id) + 1);
1266 }
1267
1268 let undo = UndoOperation {
1269 id: self.local_clock.tick(),
1270 counts,
1271 ranges: transaction.ranges,
1272 version: transaction.start.clone(),
1273 };
1274 self.apply_undo(&undo)?;
1275 self.snapshot.version.observe(undo.id);
1276
1277 Ok(Operation::Undo {
1278 undo,
1279 lamport_timestamp: self.lamport_clock.tick(),
1280 })
1281 }
1282
1283 pub fn push_transaction(
1284 &mut self,
1285 edit_ids: impl IntoIterator<Item = clock::Local>,
1286 now: Instant,
1287 ) {
1288 self.history.push_transaction(edit_ids, now);
1289 }
1290
1291 pub fn subscribe(&mut self) -> Subscription {
1292 self.subscriptions.subscribe()
1293 }
1294
1295 pub fn wait_for_edits(
1296 &mut self,
1297 edit_ids: &[clock::Local],
1298 ) -> impl 'static + Future<Output = ()> {
1299 let mut futures = Vec::new();
1300 for edit_id in edit_ids {
1301 if !self.version.observed(*edit_id) {
1302 let (tx, rx) = oneshot::channel();
1303 self.edit_id_resolvers.entry(*edit_id).or_default().push(tx);
1304 futures.push(rx);
1305 }
1306 }
1307
1308 async move {
1309 for mut future in futures {
1310 future.recv().await;
1311 }
1312 }
1313 }
1314
1315 fn resolve_edit(&mut self, edit_id: clock::Local) {
1316 for mut tx in self
1317 .edit_id_resolvers
1318 .remove(&edit_id)
1319 .into_iter()
1320 .flatten()
1321 {
1322 let _ = tx.try_send(());
1323 }
1324 }
1325}
1326
1327#[cfg(any(test, feature = "test-support"))]
1328impl Buffer {
1329 pub fn check_invariants(&self) {
1330 // Ensure every fragment is ordered by locator in the fragment tree and corresponds
1331 // to an insertion fragment in the insertions tree.
1332 let mut prev_fragment_id = Locator::min();
1333 for fragment in self.snapshot.fragments.items(&None) {
1334 assert!(fragment.id > prev_fragment_id);
1335 prev_fragment_id = fragment.id.clone();
1336
1337 let insertion_fragment = self
1338 .snapshot
1339 .insertions
1340 .get(
1341 &InsertionFragmentKey {
1342 timestamp: fragment.insertion_timestamp.local(),
1343 split_offset: fragment.insertion_offset,
1344 },
1345 &(),
1346 )
1347 .unwrap();
1348 assert_eq!(insertion_fragment.fragment_id, fragment.id);
1349 }
1350
1351 let mut cursor = self.snapshot.fragments.cursor::<Option<&Locator>>();
1352 for insertion_fragment in self.snapshot.insertions.cursor::<()>() {
1353 cursor.seek(&Some(&insertion_fragment.fragment_id), Bias::Left, &None);
1354 let fragment = cursor.item().unwrap();
1355 assert_eq!(insertion_fragment.fragment_id, fragment.id);
1356 assert_eq!(insertion_fragment.split_offset, fragment.insertion_offset);
1357 }
1358
1359 let fragment_summary = self.snapshot.fragments.summary();
1360 assert_eq!(
1361 fragment_summary.text.visible,
1362 self.snapshot.visible_text.len()
1363 );
1364 assert_eq!(
1365 fragment_summary.text.deleted,
1366 self.snapshot.deleted_text.len()
1367 );
1368 }
1369
1370 pub fn set_group_interval(&mut self, group_interval: Duration) {
1371 self.history.group_interval = group_interval;
1372 }
1373
1374 pub fn random_byte_range(&self, start_offset: usize, rng: &mut impl rand::Rng) -> Range<usize> {
1375 let end = self.clip_offset(rng.gen_range(start_offset..=self.len()), Bias::Right);
1376 let start = self.clip_offset(rng.gen_range(start_offset..=end), Bias::Right);
1377 start..end
1378 }
1379
1380 pub fn randomly_edit<T>(
1381 &mut self,
1382 rng: &mut T,
1383 old_range_count: usize,
1384 ) -> (Vec<Range<usize>>, String, Operation)
1385 where
1386 T: rand::Rng,
1387 {
1388 let mut old_ranges: Vec<Range<usize>> = Vec::new();
1389 for _ in 0..old_range_count {
1390 let last_end = old_ranges.last().map_or(0, |last_range| last_range.end + 1);
1391 if last_end > self.len() {
1392 break;
1393 }
1394 old_ranges.push(self.random_byte_range(last_end, rng));
1395 }
1396 let new_text_len = rng.gen_range(0..10);
1397 let new_text: String = crate::random_char_iter::RandomCharIter::new(&mut *rng)
1398 .take(new_text_len)
1399 .collect();
1400 log::info!(
1401 "mutating buffer {} at {:?}: {:?}",
1402 self.replica_id,
1403 old_ranges,
1404 new_text
1405 );
1406 let op = self.edit(old_ranges.iter().cloned(), new_text.as_str());
1407 (old_ranges, new_text, Operation::Edit(op))
1408 }
1409
1410 pub fn randomly_undo_redo(&mut self, rng: &mut impl rand::Rng) -> Vec<Operation> {
1411 use rand::prelude::*;
1412
1413 let mut ops = Vec::new();
1414 for _ in 0..rng.gen_range(1..=5) {
1415 if let Some(transaction) = self.history.undo_stack.choose(rng).cloned() {
1416 log::info!(
1417 "undoing buffer {} transaction {:?}",
1418 self.replica_id,
1419 transaction
1420 );
1421 ops.push(self.undo_or_redo(transaction).unwrap());
1422 }
1423 }
1424 ops
1425 }
1426}
1427
1428impl Deref for Buffer {
1429 type Target = BufferSnapshot;
1430
1431 fn deref(&self) -> &Self::Target {
1432 &self.snapshot
1433 }
1434}
1435
1436impl BufferSnapshot {
1437 pub fn as_rope(&self) -> &Rope {
1438 &self.visible_text
1439 }
1440
1441 pub fn replica_id(&self) -> ReplicaId {
1442 self.replica_id
1443 }
1444
1445 pub fn row_count(&self) -> u32 {
1446 self.max_point().row + 1
1447 }
1448
1449 pub fn len(&self) -> usize {
1450 self.visible_text.len()
1451 }
1452
1453 pub fn chars(&self) -> impl Iterator<Item = char> + '_ {
1454 self.chars_at(0)
1455 }
1456
1457 pub fn chars_for_range<T: ToOffset>(&self, range: Range<T>) -> impl Iterator<Item = char> + '_ {
1458 self.text_for_range(range).flat_map(str::chars)
1459 }
1460
1461 pub fn contains_str_at<T>(&self, position: T, needle: &str) -> bool
1462 where
1463 T: ToOffset,
1464 {
1465 let position = position.to_offset(self);
1466 position == self.clip_offset(position, Bias::Left)
1467 && self
1468 .bytes_in_range(position..self.len())
1469 .flatten()
1470 .copied()
1471 .take(needle.len())
1472 .eq(needle.bytes())
1473 }
1474
1475 pub fn text(&self) -> String {
1476 self.visible_text.to_string()
1477 }
1478
1479 pub fn deleted_text(&self) -> String {
1480 self.deleted_text.to_string()
1481 }
1482
1483 pub fn fragments(&self) -> impl Iterator<Item = &Fragment> {
1484 self.fragments.iter()
1485 }
1486
1487 pub fn text_summary(&self) -> TextSummary {
1488 self.visible_text.summary()
1489 }
1490
1491 pub fn max_point(&self) -> Point {
1492 self.visible_text.max_point()
1493 }
1494
1495 pub fn point_to_offset(&self, point: Point) -> usize {
1496 self.visible_text.point_to_offset(point)
1497 }
1498
1499 pub fn point_utf16_to_offset(&self, point: PointUtf16) -> usize {
1500 self.visible_text.point_utf16_to_offset(point)
1501 }
1502
1503 pub fn point_utf16_to_point(&self, point: PointUtf16) -> Point {
1504 self.visible_text.point_utf16_to_point(point)
1505 }
1506
1507 pub fn offset_to_point(&self, offset: usize) -> Point {
1508 self.visible_text.offset_to_point(offset)
1509 }
1510
1511 pub fn offset_to_point_utf16(&self, offset: usize) -> PointUtf16 {
1512 self.visible_text.offset_to_point_utf16(offset)
1513 }
1514
1515 pub fn version(&self) -> &clock::Global {
1516 &self.version
1517 }
1518
1519 pub fn chars_at<'a, T: ToOffset>(&'a self, position: T) -> impl Iterator<Item = char> + 'a {
1520 let offset = position.to_offset(self);
1521 self.visible_text.chars_at(offset)
1522 }
1523
1524 pub fn reversed_chars_at<'a, T: ToOffset>(
1525 &'a self,
1526 position: T,
1527 ) -> impl Iterator<Item = char> + 'a {
1528 let offset = position.to_offset(self);
1529 self.visible_text.reversed_chars_at(offset)
1530 }
1531
1532 pub fn reversed_chunks_in_range<T: ToOffset>(&self, range: Range<T>) -> rope::Chunks {
1533 let range = range.start.to_offset(self)..range.end.to_offset(self);
1534 self.visible_text.reversed_chunks_in_range(range)
1535 }
1536
1537 pub fn bytes_in_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> rope::Bytes<'a> {
1538 let start = range.start.to_offset(self);
1539 let end = range.end.to_offset(self);
1540 self.visible_text.bytes_in_range(start..end)
1541 }
1542
1543 pub fn text_for_range<'a, T: ToOffset>(&'a self, range: Range<T>) -> Chunks<'a> {
1544 let start = range.start.to_offset(self);
1545 let end = range.end.to_offset(self);
1546 self.visible_text.chunks_in_range(start..end)
1547 }
1548
1549 pub fn line_len(&self, row: u32) -> u32 {
1550 let row_start_offset = Point::new(row, 0).to_offset(self);
1551 let row_end_offset = if row >= self.max_point().row {
1552 self.len()
1553 } else {
1554 Point::new(row + 1, 0).to_offset(self) - 1
1555 };
1556 (row_end_offset - row_start_offset) as u32
1557 }
1558
1559 pub fn is_line_blank(&self, row: u32) -> bool {
1560 self.text_for_range(Point::new(row, 0)..Point::new(row, self.line_len(row)))
1561 .all(|chunk| chunk.matches(|c: char| !c.is_whitespace()).next().is_none())
1562 }
1563
1564 pub fn indent_column_for_line(&self, row: u32) -> u32 {
1565 let mut result = 0;
1566 for c in self.chars_at(Point::new(row, 0)) {
1567 if c == ' ' {
1568 result += 1;
1569 } else {
1570 break;
1571 }
1572 }
1573 result
1574 }
1575
1576 pub fn text_summary_for_range<'a, D, O: ToOffset>(&'a self, range: Range<O>) -> D
1577 where
1578 D: TextDimension,
1579 {
1580 self.visible_text
1581 .cursor(range.start.to_offset(self))
1582 .summary(range.end.to_offset(self))
1583 }
1584
1585 pub fn summaries_for_anchors<'a, D, A>(&'a self, anchors: A) -> impl 'a + Iterator<Item = D>
1586 where
1587 D: 'a + TextDimension,
1588 A: 'a + IntoIterator<Item = &'a Anchor>,
1589 {
1590 let anchors = anchors.into_iter();
1591 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1592 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1593 let mut text_cursor = self.visible_text.cursor(0);
1594 let mut position = D::default();
1595
1596 anchors.map(move |anchor| {
1597 if *anchor == Anchor::min() {
1598 return D::default();
1599 } else if *anchor == Anchor::max() {
1600 return D::from_text_summary(&self.visible_text.summary());
1601 }
1602
1603 let anchor_key = InsertionFragmentKey {
1604 timestamp: anchor.timestamp,
1605 split_offset: anchor.offset,
1606 };
1607 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1608 if let Some(insertion) = insertion_cursor.item() {
1609 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1610 if comparison == Ordering::Greater
1611 || (anchor.bias == Bias::Left
1612 && comparison == Ordering::Equal
1613 && anchor.offset > 0)
1614 {
1615 insertion_cursor.prev(&());
1616 }
1617 } else {
1618 insertion_cursor.prev(&());
1619 }
1620 let insertion = insertion_cursor.item().expect("invalid insertion");
1621 assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1622
1623 fragment_cursor.seek_forward(&Some(&insertion.fragment_id), Bias::Left, &None);
1624 let fragment = fragment_cursor.item().unwrap();
1625 let mut fragment_offset = fragment_cursor.start().1;
1626 if fragment.visible {
1627 fragment_offset += anchor.offset - insertion.split_offset;
1628 }
1629
1630 position.add_assign(&text_cursor.summary(fragment_offset));
1631 position.clone()
1632 })
1633 }
1634
1635 fn summary_for_anchor<'a, D>(&'a self, anchor: &Anchor) -> D
1636 where
1637 D: TextDimension,
1638 {
1639 if *anchor == Anchor::min() {
1640 D::default()
1641 } else if *anchor == Anchor::max() {
1642 D::from_text_summary(&self.visible_text.summary())
1643 } else {
1644 let anchor_key = InsertionFragmentKey {
1645 timestamp: anchor.timestamp,
1646 split_offset: anchor.offset,
1647 };
1648 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1649 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1650 if let Some(insertion) = insertion_cursor.item() {
1651 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1652 if comparison == Ordering::Greater
1653 || (anchor.bias == Bias::Left
1654 && comparison == Ordering::Equal
1655 && anchor.offset > 0)
1656 {
1657 insertion_cursor.prev(&());
1658 }
1659 } else {
1660 insertion_cursor.prev(&());
1661 }
1662 let insertion = insertion_cursor.item().expect("invalid insertion");
1663 assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1664
1665 let mut fragment_cursor = self.fragments.cursor::<(Option<&Locator>, usize)>();
1666 fragment_cursor.seek(&Some(&insertion.fragment_id), Bias::Left, &None);
1667 let fragment = fragment_cursor.item().unwrap();
1668 let mut fragment_offset = fragment_cursor.start().1;
1669 if fragment.visible {
1670 fragment_offset += anchor.offset - insertion.split_offset;
1671 }
1672 self.text_summary_for_range(0..fragment_offset)
1673 }
1674 }
1675
1676 fn fragment_id_for_anchor(&self, anchor: &Anchor) -> &Locator {
1677 if *anchor == Anchor::min() {
1678 &locator::MIN
1679 } else if *anchor == Anchor::max() {
1680 &locator::MAX
1681 } else {
1682 let anchor_key = InsertionFragmentKey {
1683 timestamp: anchor.timestamp,
1684 split_offset: anchor.offset,
1685 };
1686 let mut insertion_cursor = self.insertions.cursor::<InsertionFragmentKey>();
1687 insertion_cursor.seek(&anchor_key, anchor.bias, &());
1688 if let Some(insertion) = insertion_cursor.item() {
1689 let comparison = sum_tree::KeyedItem::key(insertion).cmp(&anchor_key);
1690 if comparison == Ordering::Greater
1691 || (anchor.bias == Bias::Left
1692 && comparison == Ordering::Equal
1693 && anchor.offset > 0)
1694 {
1695 insertion_cursor.prev(&());
1696 }
1697 } else {
1698 insertion_cursor.prev(&());
1699 }
1700 let insertion = insertion_cursor.item().expect("invalid insertion");
1701 debug_assert_eq!(insertion.timestamp, anchor.timestamp, "invalid insertion");
1702 &insertion.fragment_id
1703 }
1704 }
1705
1706 pub fn anchor_before<T: ToOffset>(&self, position: T) -> Anchor {
1707 self.anchor_at(position, Bias::Left)
1708 }
1709
1710 pub fn anchor_after<T: ToOffset>(&self, position: T) -> Anchor {
1711 self.anchor_at(position, Bias::Right)
1712 }
1713
1714 pub fn anchor_at<T: ToOffset>(&self, position: T, bias: Bias) -> Anchor {
1715 let offset = position.to_offset(self);
1716 if bias == Bias::Left && offset == 0 {
1717 Anchor::min()
1718 } else if bias == Bias::Right && offset == self.len() {
1719 Anchor::max()
1720 } else {
1721 let mut fragment_cursor = self.fragments.cursor::<usize>();
1722 fragment_cursor.seek(&offset, bias, &None);
1723 let fragment = fragment_cursor.item().unwrap();
1724 let overshoot = offset - *fragment_cursor.start();
1725 Anchor {
1726 timestamp: fragment.insertion_timestamp.local(),
1727 offset: fragment.insertion_offset + overshoot,
1728 bias,
1729 }
1730 }
1731 }
1732
1733 pub fn can_resolve(&self, anchor: &Anchor) -> bool {
1734 *anchor == Anchor::min()
1735 || *anchor == Anchor::max()
1736 || self.version.observed(anchor.timestamp)
1737 }
1738
1739 pub fn clip_offset(&self, offset: usize, bias: Bias) -> usize {
1740 self.visible_text.clip_offset(offset, bias)
1741 }
1742
1743 pub fn clip_point(&self, point: Point, bias: Bias) -> Point {
1744 self.visible_text.clip_point(point, bias)
1745 }
1746
1747 pub fn clip_point_utf16(&self, point: PointUtf16, bias: Bias) -> PointUtf16 {
1748 self.visible_text.clip_point_utf16(point, bias)
1749 }
1750
1751 // pub fn point_for_offset(&self, offset: usize) -> Result<Point> {
1752 // if offset <= self.len() {
1753 // Ok(self.text_summary_for_range(0..offset))
1754 // } else {
1755 // Err(anyhow!("offset out of bounds"))
1756 // }
1757 // }
1758
1759 pub fn edits_since<'a, D>(
1760 &'a self,
1761 since: &'a clock::Global,
1762 ) -> impl 'a + Iterator<Item = Edit<D>>
1763 where
1764 D: TextDimension + Ord,
1765 {
1766 self.edits_since_in_range(since, Anchor::min()..Anchor::max())
1767 }
1768
1769 pub fn edits_since_in_range<'a, D>(
1770 &'a self,
1771 since: &'a clock::Global,
1772 range: Range<Anchor>,
1773 ) -> impl 'a + Iterator<Item = Edit<D>>
1774 where
1775 D: TextDimension + Ord,
1776 {
1777 let fragments_cursor = if *since == self.version {
1778 None
1779 } else {
1780 Some(self.fragments.filter(
1781 move |summary| !since.observed_all(&summary.max_version),
1782 &None,
1783 ))
1784 };
1785 let mut cursor = self
1786 .fragments
1787 .cursor::<(Option<&Locator>, FragmentTextSummary)>();
1788
1789 let start_fragment_id = self.fragment_id_for_anchor(&range.start);
1790 cursor.seek(&Some(start_fragment_id), Bias::Left, &None);
1791 let mut visible_start = cursor.start().1.visible;
1792 let mut deleted_start = cursor.start().1.deleted;
1793 if let Some(fragment) = cursor.item() {
1794 let overshoot = range.start.offset - fragment.insertion_offset;
1795 if fragment.visible {
1796 visible_start += overshoot;
1797 } else {
1798 deleted_start += overshoot;
1799 }
1800 }
1801 let end_fragment_id = self.fragment_id_for_anchor(&range.end);
1802
1803 Edits {
1804 visible_cursor: self.visible_text.cursor(visible_start),
1805 deleted_cursor: self.deleted_text.cursor(deleted_start),
1806 fragments_cursor,
1807 undos: &self.undo_map,
1808 since,
1809 old_end: Default::default(),
1810 new_end: Default::default(),
1811 range: (start_fragment_id, range.start.offset)..(end_fragment_id, range.end.offset),
1812 }
1813 }
1814}
1815
1816struct RopeBuilder<'a> {
1817 old_visible_cursor: rope::Cursor<'a>,
1818 old_deleted_cursor: rope::Cursor<'a>,
1819 new_visible: Rope,
1820 new_deleted: Rope,
1821}
1822
1823impl<'a> RopeBuilder<'a> {
1824 fn new(old_visible_cursor: rope::Cursor<'a>, old_deleted_cursor: rope::Cursor<'a>) -> Self {
1825 Self {
1826 old_visible_cursor,
1827 old_deleted_cursor,
1828 new_visible: Rope::new(),
1829 new_deleted: Rope::new(),
1830 }
1831 }
1832
1833 fn push_tree(&mut self, len: FragmentTextSummary) {
1834 self.push(len.visible, true, true);
1835 self.push(len.deleted, false, false);
1836 }
1837
1838 fn push_fragment(&mut self, fragment: &Fragment, was_visible: bool) {
1839 debug_assert!(fragment.len > 0);
1840 self.push(fragment.len, was_visible, fragment.visible)
1841 }
1842
1843 fn push(&mut self, len: usize, was_visible: bool, is_visible: bool) {
1844 let text = if was_visible {
1845 self.old_visible_cursor
1846 .slice(self.old_visible_cursor.offset() + len)
1847 } else {
1848 self.old_deleted_cursor
1849 .slice(self.old_deleted_cursor.offset() + len)
1850 };
1851 if is_visible {
1852 self.new_visible.append(text);
1853 } else {
1854 self.new_deleted.append(text);
1855 }
1856 }
1857
1858 fn push_str(&mut self, text: &str) {
1859 self.new_visible.push(text);
1860 }
1861
1862 fn finish(mut self) -> (Rope, Rope) {
1863 self.new_visible.append(self.old_visible_cursor.suffix());
1864 self.new_deleted.append(self.old_deleted_cursor.suffix());
1865 (self.new_visible, self.new_deleted)
1866 }
1867}
1868
1869impl<'a, D: TextDimension + Ord, F: FnMut(&FragmentSummary) -> bool> Iterator for Edits<'a, D, F> {
1870 type Item = Edit<D>;
1871
1872 fn next(&mut self) -> Option<Self::Item> {
1873 let mut pending_edit: Option<Edit<D>> = None;
1874 let cursor = self.fragments_cursor.as_mut()?;
1875
1876 while let Some(fragment) = cursor.item() {
1877 if fragment.id < *self.range.start.0 {
1878 cursor.next(&None);
1879 continue;
1880 } else if fragment.id > *self.range.end.0 {
1881 break;
1882 }
1883
1884 if cursor.start().visible > self.visible_cursor.offset() {
1885 let summary = self.visible_cursor.summary(cursor.start().visible);
1886 self.old_end.add_assign(&summary);
1887 self.new_end.add_assign(&summary);
1888 }
1889
1890 if pending_edit
1891 .as_ref()
1892 .map_or(false, |change| change.new.end < self.new_end)
1893 {
1894 break;
1895 }
1896
1897 if !fragment.was_visible(&self.since, &self.undos) && fragment.visible {
1898 let mut visible_end = cursor.end(&None).visible;
1899 if fragment.id == *self.range.end.0 {
1900 visible_end = cmp::min(
1901 visible_end,
1902 cursor.start().visible + (self.range.end.1 - fragment.insertion_offset),
1903 );
1904 }
1905
1906 let fragment_summary = self.visible_cursor.summary(visible_end);
1907 let mut new_end = self.new_end.clone();
1908 new_end.add_assign(&fragment_summary);
1909 if let Some(pending_edit) = pending_edit.as_mut() {
1910 pending_edit.new.end = new_end.clone();
1911 } else {
1912 pending_edit = Some(Edit {
1913 old: self.old_end.clone()..self.old_end.clone(),
1914 new: self.new_end.clone()..new_end.clone(),
1915 });
1916 }
1917
1918 self.new_end = new_end;
1919 } else if fragment.was_visible(&self.since, &self.undos) && !fragment.visible {
1920 let mut deleted_end = cursor.end(&None).deleted;
1921 if fragment.id == *self.range.end.0 {
1922 deleted_end = cmp::min(
1923 deleted_end,
1924 cursor.start().deleted + (self.range.end.1 - fragment.insertion_offset),
1925 );
1926 }
1927
1928 if cursor.start().deleted > self.deleted_cursor.offset() {
1929 self.deleted_cursor.seek_forward(cursor.start().deleted);
1930 }
1931 let fragment_summary = self.deleted_cursor.summary(deleted_end);
1932 let mut old_end = self.old_end.clone();
1933 old_end.add_assign(&fragment_summary);
1934 if let Some(pending_edit) = pending_edit.as_mut() {
1935 pending_edit.old.end = old_end.clone();
1936 } else {
1937 pending_edit = Some(Edit {
1938 old: self.old_end.clone()..old_end.clone(),
1939 new: self.new_end.clone()..self.new_end.clone(),
1940 });
1941 }
1942
1943 self.old_end = old_end;
1944 }
1945
1946 cursor.next(&None);
1947 }
1948
1949 pending_edit
1950 }
1951}
1952
1953impl Fragment {
1954 fn is_visible(&self, undos: &UndoMap) -> bool {
1955 !undos.is_undone(self.insertion_timestamp.local())
1956 && self.deletions.iter().all(|d| undos.is_undone(*d))
1957 }
1958
1959 fn was_visible(&self, version: &clock::Global, undos: &UndoMap) -> bool {
1960 (version.observed(self.insertion_timestamp.local())
1961 && !undos.was_undone(self.insertion_timestamp.local(), version))
1962 && self
1963 .deletions
1964 .iter()
1965 .all(|d| !version.observed(*d) || undos.was_undone(*d, version))
1966 }
1967}
1968
1969impl sum_tree::Item for Fragment {
1970 type Summary = FragmentSummary;
1971
1972 fn summary(&self) -> Self::Summary {
1973 let mut max_version = clock::Global::new();
1974 max_version.observe(self.insertion_timestamp.local());
1975 for deletion in &self.deletions {
1976 max_version.observe(*deletion);
1977 }
1978 max_version.join(&self.max_undos);
1979
1980 let mut min_insertion_version = clock::Global::new();
1981 min_insertion_version.observe(self.insertion_timestamp.local());
1982 let max_insertion_version = min_insertion_version.clone();
1983 if self.visible {
1984 FragmentSummary {
1985 max_id: self.id.clone(),
1986 text: FragmentTextSummary {
1987 visible: self.len,
1988 deleted: 0,
1989 },
1990 max_version,
1991 min_insertion_version,
1992 max_insertion_version,
1993 }
1994 } else {
1995 FragmentSummary {
1996 max_id: self.id.clone(),
1997 text: FragmentTextSummary {
1998 visible: 0,
1999 deleted: self.len,
2000 },
2001 max_version,
2002 min_insertion_version,
2003 max_insertion_version,
2004 }
2005 }
2006 }
2007}
2008
2009impl sum_tree::Summary for FragmentSummary {
2010 type Context = Option<clock::Global>;
2011
2012 fn add_summary(&mut self, other: &Self, _: &Self::Context) {
2013 self.max_id.assign(&other.max_id);
2014 self.text.visible += &other.text.visible;
2015 self.text.deleted += &other.text.deleted;
2016 self.max_version.join(&other.max_version);
2017 self.min_insertion_version
2018 .meet(&other.min_insertion_version);
2019 self.max_insertion_version
2020 .join(&other.max_insertion_version);
2021 }
2022}
2023
2024impl Default for FragmentSummary {
2025 fn default() -> Self {
2026 FragmentSummary {
2027 max_id: Locator::min(),
2028 text: FragmentTextSummary::default(),
2029 max_version: clock::Global::new(),
2030 min_insertion_version: clock::Global::new(),
2031 max_insertion_version: clock::Global::new(),
2032 }
2033 }
2034}
2035
2036impl sum_tree::Item for InsertionFragment {
2037 type Summary = InsertionFragmentKey;
2038
2039 fn summary(&self) -> Self::Summary {
2040 InsertionFragmentKey {
2041 timestamp: self.timestamp,
2042 split_offset: self.split_offset,
2043 }
2044 }
2045}
2046
2047impl sum_tree::KeyedItem for InsertionFragment {
2048 type Key = InsertionFragmentKey;
2049
2050 fn key(&self) -> Self::Key {
2051 sum_tree::Item::summary(self)
2052 }
2053}
2054
2055impl InsertionFragment {
2056 fn new(fragment: &Fragment) -> Self {
2057 Self {
2058 timestamp: fragment.insertion_timestamp.local(),
2059 split_offset: fragment.insertion_offset,
2060 fragment_id: fragment.id.clone(),
2061 }
2062 }
2063
2064 fn insert_new(fragment: &Fragment) -> sum_tree::Edit<Self> {
2065 sum_tree::Edit::Insert(Self::new(fragment))
2066 }
2067}
2068
2069impl sum_tree::Summary for InsertionFragmentKey {
2070 type Context = ();
2071
2072 fn add_summary(&mut self, summary: &Self, _: &()) {
2073 *self = *summary;
2074 }
2075}
2076
2077#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, PartialOrd, Ord, Hash)]
2078pub struct FullOffset(pub usize);
2079
2080impl ops::AddAssign<usize> for FullOffset {
2081 fn add_assign(&mut self, rhs: usize) {
2082 self.0 += rhs;
2083 }
2084}
2085
2086impl ops::Add<usize> for FullOffset {
2087 type Output = Self;
2088
2089 fn add(mut self, rhs: usize) -> Self::Output {
2090 self += rhs;
2091 self
2092 }
2093}
2094
2095impl ops::Sub for FullOffset {
2096 type Output = usize;
2097
2098 fn sub(self, rhs: Self) -> Self::Output {
2099 self.0 - rhs.0
2100 }
2101}
2102
2103impl<'a> sum_tree::Dimension<'a, FragmentSummary> for usize {
2104 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
2105 *self += summary.text.visible;
2106 }
2107}
2108
2109impl<'a> sum_tree::Dimension<'a, FragmentSummary> for FullOffset {
2110 fn add_summary(&mut self, summary: &FragmentSummary, _: &Option<clock::Global>) {
2111 self.0 += summary.text.visible + summary.text.deleted;
2112 }
2113}
2114
2115impl<'a> sum_tree::Dimension<'a, FragmentSummary> for Option<&'a Locator> {
2116 fn add_summary(&mut self, summary: &'a FragmentSummary, _: &Option<clock::Global>) {
2117 *self = Some(&summary.max_id);
2118 }
2119}
2120
2121impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, FragmentTextSummary> for usize {
2122 fn cmp(
2123 &self,
2124 cursor_location: &FragmentTextSummary,
2125 _: &Option<clock::Global>,
2126 ) -> cmp::Ordering {
2127 Ord::cmp(self, &cursor_location.visible)
2128 }
2129}
2130
2131#[derive(Copy, Clone, Debug, Eq, PartialEq)]
2132enum VersionedFullOffset {
2133 Offset(FullOffset),
2134 Invalid,
2135}
2136
2137impl VersionedFullOffset {
2138 fn full_offset(&self) -> FullOffset {
2139 if let Self::Offset(position) = self {
2140 *position
2141 } else {
2142 panic!("invalid version")
2143 }
2144 }
2145}
2146
2147impl Default for VersionedFullOffset {
2148 fn default() -> Self {
2149 Self::Offset(Default::default())
2150 }
2151}
2152
2153impl<'a> sum_tree::Dimension<'a, FragmentSummary> for VersionedFullOffset {
2154 fn add_summary(&mut self, summary: &'a FragmentSummary, cx: &Option<clock::Global>) {
2155 if let Self::Offset(offset) = self {
2156 let version = cx.as_ref().unwrap();
2157 if version.observed_all(&summary.max_insertion_version) {
2158 *offset += summary.text.visible + summary.text.deleted;
2159 } else if version.observed_any(&summary.min_insertion_version) {
2160 *self = Self::Invalid;
2161 }
2162 }
2163 }
2164}
2165
2166impl<'a> sum_tree::SeekTarget<'a, FragmentSummary, Self> for VersionedFullOffset {
2167 fn cmp(&self, cursor_position: &Self, _: &Option<clock::Global>) -> cmp::Ordering {
2168 match (self, cursor_position) {
2169 (Self::Offset(a), Self::Offset(b)) => Ord::cmp(a, b),
2170 (Self::Offset(_), Self::Invalid) => cmp::Ordering::Less,
2171 (Self::Invalid, _) => unreachable!(),
2172 }
2173 }
2174}
2175
2176impl Operation {
2177 fn replica_id(&self) -> ReplicaId {
2178 operation_queue::Operation::lamport_timestamp(self).replica_id
2179 }
2180
2181 pub fn is_edit(&self) -> bool {
2182 match self {
2183 Operation::Edit { .. } => true,
2184 _ => false,
2185 }
2186 }
2187}
2188
2189impl operation_queue::Operation for Operation {
2190 fn lamport_timestamp(&self) -> clock::Lamport {
2191 match self {
2192 Operation::Edit(edit) => edit.timestamp.lamport(),
2193 Operation::Undo {
2194 lamport_timestamp, ..
2195 } => *lamport_timestamp,
2196 }
2197 }
2198}
2199
2200pub trait ToOffset {
2201 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize;
2202}
2203
2204impl ToOffset for Point {
2205 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2206 snapshot.point_to_offset(*self)
2207 }
2208}
2209
2210impl ToOffset for PointUtf16 {
2211 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2212 snapshot.point_utf16_to_offset(*self)
2213 }
2214}
2215
2216impl ToOffset for usize {
2217 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2218 assert!(*self <= snapshot.len(), "offset is out of range");
2219 *self
2220 }
2221}
2222
2223impl ToOffset for Anchor {
2224 fn to_offset<'a>(&self, snapshot: &BufferSnapshot) -> usize {
2225 snapshot.summary_for_anchor(self)
2226 }
2227}
2228
2229impl<'a, T: ToOffset> ToOffset for &'a T {
2230 fn to_offset(&self, content: &BufferSnapshot) -> usize {
2231 (*self).to_offset(content)
2232 }
2233}
2234
2235pub trait ToPoint {
2236 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point;
2237}
2238
2239impl ToPoint for Anchor {
2240 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2241 snapshot.summary_for_anchor(self)
2242 }
2243}
2244
2245impl ToPoint for usize {
2246 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2247 snapshot.offset_to_point(*self)
2248 }
2249}
2250
2251impl ToPoint for PointUtf16 {
2252 fn to_point<'a>(&self, snapshot: &BufferSnapshot) -> Point {
2253 snapshot.point_utf16_to_point(*self)
2254 }
2255}
2256
2257impl ToPoint for Point {
2258 fn to_point<'a>(&self, _: &BufferSnapshot) -> Point {
2259 *self
2260 }
2261}
2262
2263pub trait Clip {
2264 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self;
2265}
2266
2267impl Clip for usize {
2268 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2269 snapshot.clip_offset(*self, bias)
2270 }
2271}
2272
2273impl Clip for Point {
2274 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2275 snapshot.clip_point(*self, bias)
2276 }
2277}
2278
2279impl Clip for PointUtf16 {
2280 fn clip(&self, bias: Bias, snapshot: &BufferSnapshot) -> Self {
2281 snapshot.clip_point_utf16(*self, bias)
2282 }
2283}
2284
2285pub trait FromAnchor {
2286 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self;
2287}
2288
2289impl FromAnchor for Point {
2290 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2291 snapshot.summary_for_anchor(anchor)
2292 }
2293}
2294
2295impl FromAnchor for PointUtf16 {
2296 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2297 snapshot.summary_for_anchor(anchor)
2298 }
2299}
2300
2301impl FromAnchor for usize {
2302 fn from_anchor(anchor: &Anchor, snapshot: &BufferSnapshot) -> Self {
2303 snapshot.summary_for_anchor(anchor)
2304 }
2305}