Make reload debounce delay configurable via CLI flag

Author: maxdexh

src/main.rs

@@ -92,6 +92,9 @@ async fn inner_main() -> Result<(), WrappedErr> {
 		optional -m,--max-wide max_wide: NonZeroUsize
 		/// Fullscreen the pdf (hide document name, page count, etc)
 		optional -f,--fullscreen
+		/// The time to wait for the file to stop changing before reloading, in milliseconds.
+		/// Defaults to the minimum value of 50ms.
+		optional --reload-delay reload_delay: u64
 		/// The number of pages to prerender surrounding the currently-shown page; 0 means no
 		/// limit. By default, there is no limit.
 		optional -p,--prerender prerender: usize
@@ -163,7 +166,11 @@ async fn inner_main() -> Result<(), WrappedErr> {
 		watch_to_render_tx,
 		path.file_name()
 			.ok_or(WrappedErr("Path does not have a last component??".into()))?
-			.to_owned()
+			.to_owned(),
+		flags
+			.reload_delay
+			.map(Duration::from_millis)
+			.unwrap_or_default()
 	))
 	.map_err(|e| WrappedErr(format!("Couldn't start watching the provided file: {e}").into()))?;
 
@@ -462,18 +469,19 @@ async fn enter_redraw_loop(
 	}
 }
 
-// Only reload once the file has not changed for 1 second
-const DEBOUNCE_DELAY: Duration = Duration::from_millis(1000);
+const MIN_DEBOUNCE_DELAY: Duration = Duration::from_millis(50);
 
 fn on_notify_ev(
 	to_tui_tx: flume::Sender<Result<RenderInfo, RenderError>>,
 	to_render_tx: flume::Sender<RenderNotif>,
-	file_name: OsString
+	file_name: OsString,
+	debounce_delay: Duration
 ) -> impl Fn(notify::Result<Event>) {
+	let debounce_delay = debounce_delay.max(MIN_DEBOUNCE_DELAY);
 	let last_event: Mutex<Result<(), RenderError>> = Mutex::new(Ok(()));
 	let last_event = Arc::new(last_event);
 
-	let debouncer = EventDebouncer::new(DEBOUNCE_DELAY, {
+	let debouncer = EventDebouncer::new(debounce_delay, {
 		let last_event = last_event.clone();
 		move |()| {
 			let event = mem::replace(&mut *last_event.lock().unwrap(), Ok(()));