From 3ec149f7c09ab0bb4f0264a730ebfcbd0868cefc Mon Sep 17 00:00:00 2001 From: Daniel Faust Date: Sat, 14 Sep 2024 15:00:36 +0200 Subject: [PATCH 1/2] Fix ordering of debounced events Fixes #636. --- CHANGELOG.md | 6 +++ notify-debouncer-full/src/lib.rs | 49 ++++++++++++++----- .../sort_events_chronologically.hjson | 42 ++++++++++++++++ .../sort_events_with_reordering.hjson | 42 ++++++++++++++++ 4 files changed, 127 insertions(+), 12 deletions(-) create mode 100644 notify-debouncer-full/test_cases/sort_events_chronologically.hjson create mode 100644 notify-debouncer-full/test_cases/sort_events_with_reordering.hjson diff --git a/CHANGELOG.md b/CHANGELOG.md index e879dba6..638f4f2b 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -4,6 +4,12 @@ v5 maintenance branch is on `v5_maintenance` after `5.2.0` v4 commits split out to branch `v4_maintenance` starting with `4.0.16` +## debouncer-full 0.4.1 (unreleased) + +- FIX: ordering of debounced events could lead to a panic with Rust 1.81.0 and above [#636] + +[#636]: https://github.com/notify-rs/notify/issues/636 + ## notify 7.0.0 - CHANGE: raise MSRV to 1.72 diff --git a/notify-debouncer-full/src/lib.rs b/notify-debouncer-full/src/lib.rs index 0996fd66..18262edd 100644 --- a/notify-debouncer-full/src/lib.rs +++ b/notify-debouncer-full/src/lib.rs @@ -243,17 +243,7 @@ impl DebounceDataInner { self.queues = queues_remaining; - // order events for different files chronologically, but keep the order of events for the same file - events_expired.sort_by(|event_a, event_b| { - // use the last path because rename events are emitted for the target path - if event_a.paths.last() == event_b.paths.last() { - std::cmp::Ordering::Equal - } else { - event_a.time.cmp(&event_b.time) - } - }); - - events_expired + sort_events(events_expired) } /// Returns all currently stored errors @@ -713,6 +703,39 @@ pub fn new_debouncer( ) } +fn sort_events(events: Vec) -> Vec { + let mut sorted = Vec::with_capacity(events.len()); + + // group events by path + let mut events_by_path: HashMap<_, VecDeque<_>> = + events.into_iter().fold(HashMap::new(), |mut acc, event| { + acc.entry(event.paths.last().cloned().unwrap_or_default()) + .or_default() + .push_back(event); + acc + }); + + // push events for different paths in chronological order and keep the order of events with the same path + while !events_by_path.is_empty() { + let min_time = events_by_path + .values() + .map(|events| events[0].time) + .min() + .unwrap(); + + for events in events_by_path.values_mut() { + while events.front().is_some_and(|event| event.time <= min_time) { + let event = events.pop_front().unwrap(); + sorted.push(event); + } + } + + events_by_path.retain(|_, events| !events.is_empty()); + } + + sorted +} + #[cfg(test)] mod tests { use std::{fs, path::Path}; @@ -761,7 +784,9 @@ mod tests { "emit_close_events_only_once", "emit_modify_event_after_close_event", "emit_needs_rescan_event", - "read_file_id_without_create_event" + "read_file_id_without_create_event", + "sort_events_chronologically", + "sort_events_with_reordering" )] file_name: &str, ) { diff --git a/notify-debouncer-full/test_cases/sort_events_chronologically.hjson b/notify-debouncer-full/test_cases/sort_events_chronologically.hjson new file mode 100644 index 00000000..363b22e3 --- /dev/null +++ b/notify-debouncer-full/test_cases/sort_events_chronologically.hjson @@ -0,0 +1,42 @@ +{ + state: { + queues: { + /watch/file-1: { + events: [ + { kind: "create-any", paths: ["*"], time: 2 } + { kind: "modify-any", paths: ["*"], time: 3 } + ] + } + /watch/file-2: { + events: [ + { kind: "create-any", paths: ["*"], time: 1 } + { kind: "modify-any", paths: ["*"], time: 4 } + ] + } + } + } + expected: { + queues: { + /watch/file-1: { + events: [ + { kind: "create-any", paths: ["*"], time: 2 } + { kind: "modify-any", paths: ["*"], time: 3 } + ] + } + /watch/file-2: { + events: [ + { kind: "create-any", paths: ["*"], time: 1 } + { kind: "modify-any", paths: ["*"], time: 4 } + ] + } + } + events: { + long: [ + { kind: "create-any", paths: ["/watch/file-2"], time: 1 } + { kind: "create-any", paths: ["/watch/file-1"], time: 2 } + { kind: "modify-any", paths: ["/watch/file-1"], time: 3 } + { kind: "modify-any", paths: ["/watch/file-2"], time: 4 } + ] + } + } +} diff --git a/notify-debouncer-full/test_cases/sort_events_with_reordering.hjson b/notify-debouncer-full/test_cases/sort_events_with_reordering.hjson new file mode 100644 index 00000000..030bab1b --- /dev/null +++ b/notify-debouncer-full/test_cases/sort_events_with_reordering.hjson @@ -0,0 +1,42 @@ +{ + state: { + queues: { + /watch/file-1: { + events: [ + { kind: "create-any", paths: ["*"], time: 2 } + { kind: "modify-any", paths: ["*"], time: 3 } + ] + } + /watch/file-2: { + events: [ + { kind: "rename-to", paths: ["*"], time: 4 } + { kind: "modify-any", paths: ["*"], time: 1 } + ] + } + } + } + expected: { + queues: { + /watch/file-1: { + events: [ + { kind: "create-any", paths: ["*"], time: 2 } + { kind: "modify-any", paths: ["*"], time: 3 } + ] + } + /watch/file-2: { + events: [ + { kind: "rename-to", paths: ["*"], time: 4 } + { kind: "modify-any", paths: ["*"], time: 1 } + ] + } + } + events: { + long: [ + { kind: "create-any", paths: ["/watch/file-1"], time: 2 } + { kind: "modify-any", paths: ["/watch/file-1"], time: 3 } + { kind: "rename-to", paths: ["/watch/file-2"], time: 4 } + { kind: "modify-any", paths: ["/watch/file-2"], time: 1 } + ] + } + } +} From bc1bf69e87e78f1cdf6c799c924ae71ecedef947 Mon Sep 17 00:00:00 2001 From: Daniel Faust Date: Sat, 14 Sep 2024 21:23:47 +0200 Subject: [PATCH 2/2] Improve `sort_events` performance --- notify-debouncer-full/src/lib.rs | 39 ++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 14 deletions(-) diff --git a/notify-debouncer-full/src/lib.rs b/notify-debouncer-full/src/lib.rs index 18262edd..6870f853 100644 --- a/notify-debouncer-full/src/lib.rs +++ b/notify-debouncer-full/src/lib.rs @@ -62,7 +62,8 @@ mod cache; mod testing; use std::{ - collections::{HashMap, VecDeque}, + cmp::Reverse, + collections::{BinaryHeap, HashMap, VecDeque}, path::{Path, PathBuf}, sync::{ atomic::{AtomicBool, Ordering}, @@ -716,21 +717,31 @@ fn sort_events(events: Vec) -> Vec { }); // push events for different paths in chronological order and keep the order of events with the same path - while !events_by_path.is_empty() { - let min_time = events_by_path - .values() - .map(|events| events[0].time) - .min() - .unwrap(); - - for events in events_by_path.values_mut() { - while events.front().is_some_and(|event| event.time <= min_time) { - let event = events.pop_front().unwrap(); - sorted.push(event); - } + + let mut min_time_heap = events_by_path + .iter() + .map(|(path, events)| Reverse((events[0].time, path.clone()))) + .collect::>(); + + while let Some(Reverse((min_time, path))) = min_time_heap.pop() { + // unwrap is safe because only paths from `events_by_path` are added to `min_time_heap` + // and they are never removed from `events_by_path`. + let events = events_by_path.get_mut(&path).unwrap(); + + let mut push_next = false; + + while events.front().is_some_and(|event| event.time <= min_time) { + // unwrap is safe beause `pop_front` mus return some in order to enter the loop + let event = events.pop_front().unwrap(); + sorted.push(event); + push_next = true; } - events_by_path.retain(|_, events| !events.is_empty()); + if push_next { + if let Some(event) = events.front() { + min_time_heap.push(Reverse((event.time, path))); + } + } } sorted