Make Patch::compose work

This commit is contained in:
Antonio Scandurra 2021-11-12 15:07:28 +01:00
parent 6e882bcd02
commit f49c9db423

View file

@ -1,204 +1,175 @@
use std::{iter::Peekable, mem, ops::Range};
use std::{cmp, iter::Peekable, mem, ops::Range};
type Edit = buffer::Edit<u32>;
#[derive(Default, Debug, PartialEq, Eq)]
struct Patch(Vec<Edit>);
fn compose_edits(old_edit: &Edit, new_edit: &Edit) -> Edit {
let mut composed = old_edit.clone();
if old_edit.new.start > new_edit.old.start {
composed.old.start -= old_edit.new.start - new_edit.old.start;
composed.new.start = new_edit.old.start;
}
if new_edit.old.end > old_edit.new.end {
composed.old.end += new_edit.old.end - old_edit.new.end;
composed.new.end = new_edit.old.end;
}
let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
composed.new.end = (composed.new.end as i32 + new_edit_delta) as u32;
composed
}
fn merge_edits(left_edit: &mut Option<Edit>, right_edit: Edit) {
if let Some(left_edit) = left_edit.as_mut() {
left_edit.old.end = right_edit.old.end;
left_edit.new.end = right_edit.new.end;
} else {
*left_edit = Some(right_edit);
}
}
impl Patch {
fn compose(&self, new: &Self) -> Patch {
let mut composed = Vec::new();
let mut old_edits = self.0.iter().cloned().peekable();
let mut new_edits = new.0.iter().cloned().peekable();
let old_delta = 0;
fn compose(&self, other: &Self) -> Self {
let mut old_edits_iter = self.0.iter().cloned().peekable();
let mut new_edits_iter = other.0.iter().cloned().peekable();
let mut composed = Patch(Vec::new());
'outer: loop {
// Find the next edit in the intermediate coordinate space
// Then merge together all old and new edits that intersect this edit in the intermediate coordinate space.
let mut pending_old_edit = None;
let mut pending_new_edit = None;
let mut intermediate_end = u32::MAX;
loop {
match (old_edits.peek(), new_edits.peek()) {
(None, None) => break,
(Some(edit), None) => {
if edit.new.start <= intermediate_end {
intermediate_end = edit.new.end;
merge_edits(&mut pending_old_edit, old_edits.next().unwrap())
} else {
break;
}
}
(None, Some(edit)) => {
if edit.old.start <= intermediate_end {
intermediate_end = edit.old.end;
merge_edits(&mut pending_new_edit, new_edits.next().unwrap());
}
}
(Some(old_edit), Some(new_edit)) => {
if old_edit.new.start <= new_edit.old.start {
if old_edit.new.start <= intermediate_end {
intermediate_end = old_edit.new.end;
merge_edits(&mut pending_old_edit, old_edits.next().unwrap())
} else {
break;
}
} else {
if new_edit.old.start <= intermediate_end {
intermediate_end = new_edit.old.end;
merge_edits(&mut pending_new_edit, new_edits.next().unwrap());
} else {
break;
}
}
}
}
}
match (pending_old_edit, pending_new_edit) {
let mut old_start = 0;
let mut new_start = 0;
loop {
match (old_edits_iter.peek_mut(), new_edits_iter.peek_mut()) {
(None, None) => break,
(None, Some(new_edit)) => todo!(),
(Some(old_edit), None) => todo!(),
(Some(old_edit), None) => {
let catchup = old_edit.old.start - old_start;
old_start += catchup;
new_start += catchup;
let old_end = old_start + old_edit.old.len() as u32;
let new_end = new_start + old_edit.new.len() as u32;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_start = old_end;
new_start = new_end;
old_edits_iter.next();
}
(None, Some(new_edit)) => {
let catchup = new_edit.new.start - new_start;
old_start += catchup;
new_start += catchup;
let old_end = old_start + new_edit.old.len() as u32;
let new_end = new_start + new_edit.new.len() as u32;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_start = old_end;
new_start = new_end;
new_edits_iter.next();
}
(Some(old_edit), Some(new_edit)) => {
let composed = compose_edits(&old_edit, &new_edit);
if old_edit.new.end < new_edit.old.start {
let catchup = old_edit.old.start - old_start;
old_start += catchup;
new_start += catchup;
let old_end = old_start + old_edit.old.len() as u32;
let new_end = new_start + old_edit.new.len() as u32;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_start = old_end;
new_start = new_end;
old_edits_iter.next();
continue;
} else if new_edit.old.end < old_edit.new.start {
let catchup = new_edit.new.start - new_start;
old_start += catchup;
new_start += catchup;
let old_end = old_start + new_edit.old.len() as u32;
let new_end = new_start + new_edit.new.len() as u32;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_start = old_end;
new_start = new_end;
new_edits_iter.next();
} else {
if old_edit.new.start < new_edit.old.start {
let catchup = old_edit.old.start - old_start;
old_start += catchup;
new_start += catchup;
let overshoot = new_edit.old.start - old_edit.new.start;
let old_end = cmp::min(old_start + overshoot, old_edit.old.end);
let new_end = new_start + overshoot;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_edit.old.start += overshoot;
old_edit.new.start += overshoot;
old_start = old_end;
new_start = new_end;
} else {
let catchup = new_edit.new.start - new_start;
old_start += catchup;
new_start += catchup;
let overshoot = old_edit.new.start - new_edit.old.start;
let old_end = old_start + overshoot;
let new_end = cmp::min(new_start + overshoot, new_edit.new.end);
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
new_edit.old.start += overshoot;
new_edit.new.start += overshoot;
old_start = old_end;
new_start = new_end;
}
if old_edit.new.end > new_edit.old.end {
let old_len =
cmp::min(old_edit.old.len() as u32, new_edit.old.len() as u32);
let old_end = old_start + old_len;
let new_end = new_start + new_edit.new.len() as u32;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
old_edit.old.start = old_end;
old_edit.new.start = new_edit.old.end;
old_start = old_end;
new_start = new_end;
new_edits_iter.next();
} else {
let new_len =
cmp::min(old_edit.new.len() as u32, new_edit.new.len() as u32);
let old_end = old_start + old_edit.old.len() as u32;
let new_end = new_start + new_len;
composed.push(Edit {
old: old_start..old_end,
new: new_start..new_end,
});
new_edit.old.start = old_edit.new.end;
new_edit.new.start = new_end;
old_start = old_end;
new_start = new_end;
old_edits_iter.next();
}
}
}
}
}
Patch(composed)
composed
}
fn compose1(&self, new: &Self) -> Patch {
let mut composed = Vec::<Edit>::new();
let mut old_edits = self.0.iter().cloned().peekable();
let mut old_delta = 0;
let mut new_delta = 0;
let mut intermediate_start;
let mut intermediate_end = 0;
for mut new_edit in new.0.iter().cloned() {
eprintln!("edit {:?}", new_edit);
let new_edit_delta = new_edit.new.len() as i32 - new_edit.old.len() as i32;
if let Some(last_edit) = composed.last_mut() {
if intermediate_end >= new_edit.old.start {
if new_edit.old.end > intermediate_end {
last_edit.old.end += new_edit.old.end - intermediate_end;
last_edit.new.end += new_edit.old.end - intermediate_end;
intermediate_end = new_edit.old.end;
}
last_edit.new.end = (last_edit.new.end as i32 + new_edit_delta) as u32;
new_delta += new_edit_delta;
eprintln!(" merged {:?}", &composed);
continue;
}
}
intermediate_start = new_edit.old.start;
intermediate_end = new_edit.old.end;
new_edit.old.start = (new_edit.old.start as i32 - old_delta) as u32;
new_edit.old.end = (new_edit.old.end as i32 - old_delta) as u32;
while let Some(old_edit) = old_edits.peek() {
let old_edit_delta = old_edit.new.len() as i32 - old_edit.old.len() as i32;
if old_edit.new.end < intermediate_start {
let mut old_edit = old_edit.clone();
old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
new_edit.old.start = (new_edit.old.start as i32 - old_edit_delta) as u32;
new_edit.old.end = (new_edit.old.end as i32 - old_edit_delta) as u32;
composed.push(old_edit);
eprintln!(" pushed preceding {:?}", &composed);
} else if old_edit.new.start <= intermediate_end {
if old_edit.new.start < intermediate_start {
new_edit.new.start -= intermediate_start - old_edit.new.start;
new_edit.old.start -= intermediate_start - old_edit.new.start;
}
if old_edit.new.end > intermediate_end {
new_edit.new.end += old_edit.new.end - intermediate_end;
new_edit.old.end += old_edit.new.end - intermediate_end;
intermediate_end = old_edit.new.end;
}
eprintln!(" expanded w/ intersecting {:?} - {:?}", old_edit, new_edit);
new_edit.old.end = (new_edit.old.end as i32 - old_edit_delta) as u32;
} else {
break;
}
old_delta += old_edit_delta;
old_edits.next();
}
new_delta += new_edit_delta;
composed.push(new_edit);
eprintln!(" pushing {:?}", &composed);
fn push(&mut self, edit: Edit) {
if edit.old.len() == 0 && edit.new.len() == 0 {
return;
}
while let Some(mut old_edit) = old_edits.next() {
let old_edit_delta = old_edit.new.len() as i32 - old_edit.old.len() as i32;
if let Some(last_edit) = composed.last_mut() {
if intermediate_end >= old_edit.new.start {
if old_edit.new.end > intermediate_end {
last_edit.old.end += old_edit.new.end - intermediate_end;
last_edit.new.end += old_edit.new.end - intermediate_end;
intermediate_end = old_edit.new.end;
}
last_edit.old.end = (last_edit.old.end as i32 - old_edit_delta) as u32;
eprintln!(" merged {:?}", &composed);
continue;
}
if let Some(last) = self.0.last_mut() {
if last.old.end >= edit.old.start {
last.old.end = edit.old.end;
last.new.end = edit.new.end;
} else {
self.0.push(edit);
}
old_edit.new.start = (old_edit.new.start as i32 + new_delta) as u32;
old_edit.new.end = (old_edit.new.end as i32 + new_delta) as u32;
composed.push(old_edit);
} else {
self.0.push(edit);
}
Patch(composed)
}
fn invert(&mut self) -> &mut Self {
for edit in &mut self.0 {
mem::swap(&mut edit.old, &mut edit.new);
}
self
}
}
fn edit_delta(edit: &Edit) -> i32 {
edit.new.len() as i32 - edit.old.len() as i32
}
fn apply_delta(range: &mut Range<u32>, delta: i32) {
range.start = (range.start as i32 + delta) as u32;
range.end = (range.end as i32 + delta) as u32;
}
#[cfg(test)]
@ -372,25 +343,25 @@ mod tests {
);
}
#[test]
fn test_compose_edits() {
assert_eq!(
compose_edits(
&Edit {
old: 3..3,
new: 3..6,
},
&Edit {
old: 2..7,
new: 2..4,
},
),
Edit {
old: 2..4,
new: 2..4
}
);
}
// #[test]
// fn test_compose_edits() {
// assert_eq!(
// compose_edits(
// &Edit {
// old: 3..3,
// new: 3..6,
// },
// &Edit {
// old: 2..7,
// new: 2..4,
// },
// ),
// Edit {
// old: 2..4,
// new: 2..4
// }
// );
// }
#[gpui::test]
fn test_two_new_edits_touching_one_old_edit() {
@ -428,11 +399,11 @@ mod tests {
);
}
#[gpui::test(iterations = 1000)]
#[gpui::test(iterations = 100, seed = 1)]
fn test_random_patch_compositions(mut rng: StdRng) {
let operations = env::var("OPERATIONS")
.map(|i| i.parse().expect("invalid `OPERATIONS` variable"))
.unwrap_or(2);
.unwrap_or(5);
let initial_chars = (0..rng.gen_range(0..=10))
.map(|_| rng.gen_range(b'a'..=b'z') as char)
@ -448,6 +419,7 @@ mod tests {
let mut delta = 0i32;
let mut last_edit_end = 0;
let mut edits = Vec::new();
for _ in 0..operations {
if last_edit_end >= expected_chars.len() {
break;