From b4e1774993c17197752b548b57a219e8d1cf48db Mon Sep 17 00:00:00 2001
From: Joakim Hulthe <joakim@hulthe.net>
Date: Sat, 2 Oct 2021 17:44:08 +0200
Subject: [PATCH] daemon: Fix poll after finished

---
 cli/src/daemon.rs | 67 +++++++++++++++++++++++++++--------------------
 1 file changed, 39 insertions(+), 28 deletions(-)

diff --git a/cli/src/daemon.rs b/cli/src/daemon.rs
index aedf366..cc3b051 100644
--- a/cli/src/daemon.rs
+++ b/cli/src/daemon.rs
@@ -22,25 +22,27 @@ pub fn run(opt: DaemonOpt) -> Result<(), Error> {
 
     let rt = Runtime::new()?;
     rt.block_on(async {
-        let (tx, rx) = mpsc::channel();
-
         info!("creating output file");
         fs::write(&opt.file, b"").await?;
 
+        // setup INotify watcher
+        let (tx, rx) = mpsc::channel();
         let mut watcher = INotifyWatcher::new_raw(tx).unwrap();
         watcher
             .watch(&opt.file, RecursiveMode::NonRecursive)
             .expect("failed to watch file");
+        let mut inotify = proxy_channel(rx);
 
+        // perform first category update
         soft_fail(update_category_list(opt, cookie).await);
         let mut last_update = Instant::now();
 
-        let mut wfe: JoinHandle<_> = spawn(wait_for_event(opt, cookie));
-
-        let mut rx = proxy_channel(rx);
+        // start WFE long-poll
+        let mut wfe_handle: Option<JoinHandle<_>> = Some(spawn(wait_for_event(opt, cookie)));
 
         loop {
-            let event = match rx.recv().await {
+            // wait for next inotify event
+            let event = match inotify.recv().await {
                 Some(event) => event,
                 None => return Err(Error::ChannelClosed),
             };
@@ -48,33 +50,42 @@ pub fn run(opt: DaemonOpt) -> Result<(), Error> {
             debug!("event op {:?}", event.op);
 
             match event.op {
-                Ok(Op::CHMOD) => { /* YEESSS */ }
+                Ok(Op::CHMOD) => { /* we only care about this event */ }
                 _ => continue,
             }
 
             debug!("CHMOD event detected");
 
-            let update_categories;
-            let restart_wfe;
+            // poll wfe and decide whether we want to restart it, and whether we want to update the
+            // categories
+            let restart_wfe: bool;
+            let update_categories: Option<bool>;
+            if let Some(mut wfe) = wfe_handle.take() {
+                match poll!(&mut wfe) {
+                    Poll::Ready(Ok(Ok(_wfe))) => {
+                        restart_wfe = true;
+                        update_categories = Some(true);
+                    }
+                    Poll::Ready(Ok(Err(e))) => {
+                        error!("error waiting for event (falling back to timing): {}", e);
+                        restart_wfe = false;
+                        update_categories = None;
+                    }
+                    Poll::Ready(Err(_)) => {
+                        restart_wfe = false;
+                        update_categories = None;
+                    }
+                    Poll::Pending => {
+                        restart_wfe = false;
+                        update_categories = Some(false);
 
-            match poll!(&mut wfe) {
-                Poll::Ready(Ok(Ok(_wfe))) => {
-                    restart_wfe = true;
-                    update_categories = Some(true);
-                }
-                Poll::Ready(Ok(Err(e))) => {
-                    error!("error waiting for event (falling back to timing): {}", e);
-                    restart_wfe = false;
-                    update_categories = None;
-                }
-                Poll::Ready(Err(_)) => {
-                    restart_wfe = false;
-                    update_categories = None;
-                }
-                Poll::Pending => {
-                    restart_wfe = false;
-                    update_categories = Some(false);
+                        // wfe task is not complete, we will continue waiting for it next loop
+                        wfe_handle = Some(wfe)
+                    }
                 }
+            } else {
+                restart_wfe = false;
+                update_categories = None;
             }
 
             let elapsed = last_update.elapsed();
@@ -94,13 +105,13 @@ pub fn run(opt: DaemonOpt) -> Result<(), Error> {
             }
 
             if update_categories || restart_wfe {
-                wfe = spawn(wait_for_event(opt, cookie));
+                wfe_handle = Some(spawn(wait_for_event(opt, cookie)));
             }
         }
     })
 }
 
-#[derive(Deserialize)]
+#[derive(Clone, Debug, Deserialize)]
 struct WaitForEvent {
     #[allow(dead_code)]
     timeout: bool,