Wait for FS activity to stop before proceeding; use interrupt handling

src/main.rs

@@ -1,3 +1,4 @@
+#![feature(mpsc_select)]
 #![feature(process_exec)]
 
 #[macro_use]
@@ -24,8 +25,9 @@ mod notification_filter;
 mod runner;
 mod watcher;
 
-use std::sync::mpsc::{channel, Receiver, RecvError};
-use std::{env, thread, time};
+use std::env;
+use std::sync::mpsc::{channel, Receiver};
+use std::time::Duration;
 use std::path::{Path, PathBuf};
 
 use notification_filter::NotificationFilter;
@@ -66,6 +68,7 @@ fn init_logger(debug: bool) {
 }
 
 fn main() {
+    let interrupt_rx = interrupt_handler::install();
     let args = args::get_args();
 
     init_logger(args.debug);
@@ -121,38 +124,53 @@ fn main() {
     }
 
     while !interrupt_handler::interrupt_requested() {
-        let e = wait(&rx, &filter).expect("error when waiting for filesystem changes");
+        match wait(&rx, &interrupt_rx, &filter) {
+            Some(paths) => {
+                let updated = paths
+                    .iter()
+                    .map(|p| p.to_str().unwrap())
+                    .collect();
 
-        debug!("{:?}: {:?}", e.op, e.path);
-
-        // TODO: update wait to return all paths
-        let updated: Vec<&str> = e.path
-            .iter()
-            .map(|p| p.to_str().unwrap())
-            .collect();
-
-        runner.run_command(&cmd, updated);
-    }
-}
-
-fn wait(rx: &Receiver<Event>, filter: &NotificationFilter) -> Result<Event, RecvError> {
-    loop {
-        // Block on initial notification
-        let e = try!(rx.recv());
-        if let Some(ref path) = e.path {
-            if filter.is_excluded(path) {
-                continue;
+                runner.run_command(&cmd, updated);
+            },
+            None => {
+                // interrupted
             }
         }
-
-        // Accumulate subsequent events
-        thread::sleep(time::Duration::from_millis(250));
-
-        // Drain rx buffer and drop them
-        while let Ok(_) = rx.try_recv() {
-            // nothing to do here
-        }
-
-        return Ok(e);
     }
 }
+
+fn wait(rx: &Receiver<Event>, interrupt_rx: &Receiver<()>, filter: &NotificationFilter) -> Option<Vec<PathBuf>> {
+    let mut paths = vec![];
+
+    loop {
+        select! {
+            _ = interrupt_rx.recv() => { return None; },
+            ev = rx.recv() => {
+                let e = ev.expect("error when reading event");
+
+                if let Some(ref path) = e.path {
+                    if !filter.is_excluded(path) {
+                        paths.push(path.to_owned());
+                        break;
+                    }
+                }
+            }
+        };
+    }
+
+    // Wait for filesystem activity to cool off
+    // Unfortunately, we can't use select! with recv_timeout :(
+    let timeout = Duration::from_millis(500);
+    while let Ok(e) = rx.recv_timeout(timeout) {
+        if interrupt_handler::interrupt_requested() {
+            break;
+        }
+
+        if let Some(ref path) = e.path {
+            paths.push(path.to_owned());
+        }
+    }
+
+    Some(paths)
+}