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|
use anyhow::{Context, Result};
use notify::{
Event, EventKind,
event::{AccessKind, AccessMode, MetadataKind, ModifyKind, RenameMode},
};
use std::{
sync::{
atomic::Ordering::Relaxed,
mpsc::{RecvTimeoutError, Sender, SyncSender, sync_channel},
},
thread,
time::Duration,
};
use super::{EXERCISE_RUNNING, WatchEvent};
const DEBOUNCE_DURATION: Duration = Duration::from_millis(200);
pub struct NotifyEventHandler {
error_sender: Sender<WatchEvent>,
// Sends the index of the updated exercise.
update_sender: SyncSender<usize>,
// Used to report which exercise was modified.
exercise_names: &'static [&'static [u8]],
}
impl NotifyEventHandler {
pub fn build(
watch_event_sender: Sender<WatchEvent>,
exercise_names: &'static [&'static [u8]],
) -> Result<Self> {
let (update_sender, update_receiver) = sync_channel(0);
let error_sender = watch_event_sender.clone();
// Debouncer
thread::Builder::new()
.spawn(move || {
let mut exercise_updated = vec![false; exercise_names.len()];
loop {
match update_receiver.recv_timeout(DEBOUNCE_DURATION) {
Ok(exercise_ind) => exercise_updated[exercise_ind] = true,
Err(RecvTimeoutError::Timeout) => {
for (exercise_ind, updated) in exercise_updated.iter_mut().enumerate() {
if *updated {
if watch_event_sender
.send(WatchEvent::FileChange { exercise_ind })
.is_err()
{
break;
}
*updated = false;
}
}
}
Err(RecvTimeoutError::Disconnected) => break,
}
}
})
.context("Failed to spawn a thread to debounce file changes")?;
Ok(Self {
error_sender,
update_sender,
exercise_names,
})
}
}
impl notify::EventHandler for NotifyEventHandler {
fn handle_event(&mut self, input_event: notify::Result<Event>) {
if EXERCISE_RUNNING.load(Relaxed) {
return;
}
let input_event = match input_event {
Ok(v) => v,
Err(e) => {
// An error occurs when the receiver is dropped.
// After dropping the receiver, the watcher guard should also be dropped.
let _ = self.error_sender.send(WatchEvent::NotifyErr(e));
return;
}
};
match input_event.kind {
EventKind::Any => (),
EventKind::Modify(modify_kind) => match modify_kind {
ModifyKind::Any | ModifyKind::Data(_) => (),
ModifyKind::Name(rename_mode) => match rename_mode {
RenameMode::Any | RenameMode::To => (),
RenameMode::From | RenameMode::Both | RenameMode::Other => return,
},
ModifyKind::Metadata(metadata_kind) => match metadata_kind {
MetadataKind::Any | MetadataKind::WriteTime => (),
MetadataKind::AccessTime
| MetadataKind::Permissions
| MetadataKind::Ownership
| MetadataKind::Extended
| MetadataKind::Other => return,
},
ModifyKind::Other => return,
},
EventKind::Access(access_kind) => match access_kind {
AccessKind::Any => (),
AccessKind::Close(access_mode) => match access_mode {
AccessMode::Any | AccessMode::Write => (),
AccessMode::Execute | AccessMode::Read | AccessMode::Other => return,
},
AccessKind::Read | AccessKind::Open(_) | AccessKind::Other => return,
},
EventKind::Create(_) | EventKind::Remove(_) | EventKind::Other => return,
}
let _ = input_event
.paths
.into_iter()
.filter_map(|path| {
let file_name = path.file_name()?.to_str()?.as_bytes();
let [file_name_without_ext @ .., b'.', b'r', b's'] = file_name else {
return None;
};
self.exercise_names
.iter()
.position(|exercise_name| *exercise_name == file_name_without_ext)
})
.try_for_each(|exercise_ind| self.update_sender.send(exercise_ind));
}
}
|
