Allow web user to cancel transmission in progress

[broadcaster] / radio / radio.go

diff --git a/radio/radio.go b/radio/radio.go
index f6b3b50afd08aa190b1413b6b608f588c0525576..bcf5e38d7542a8f6c545147e274bdf02ab1d4bbd 100644 (file)
--- a/radio/radio.go
+++ b/radio/radio.go
@@ -60,17 +60,18 @@ func main() {
        fileSpecChan := make(chan []protocol.FileSpec)
        go filesWorker(config.CachePath, fileSpecChan)
 
+       stop := make(chan bool)
        playlistSpecChan := make(chan []protocol.PlaylistSpec)
-       go playlistWorker(playlistSpecChan)
+       go playlistWorker(playlistSpecChan, stop)
 
        for {
-               runWebsocket(fileSpecChan, playlistSpecChan)
+               runWebsocket(fileSpecChan, playlistSpecChan, stop)
                log.Println("Websocket failed, retry in 30 seconds")
                time.Sleep(time.Second * time.Duration(30))
        }
 }
 
-func runWebsocket(fileSpecChan chan []protocol.FileSpec, playlistSpecChan chan []protocol.PlaylistSpec) error {
+func runWebsocket(fileSpecChan chan []protocol.FileSpec, playlistSpecChan chan []protocol.PlaylistSpec, stop chan bool) error {
        log.Println("Establishing websocket connection to:", config.WebsocketURL())
        ws, err := websocket.Dial(config.WebsocketURL(), "", config.ServerURL)
        if err != nil {
@@ -120,6 +121,10 @@ func runWebsocket(fileSpecChan chan []protocol.FileSpec, playlistSpecChan chan [
                        playlistsMsg := msg.(protocol.PlaylistsMessage)
                        playlistSpecChan <- playlistsMsg.Playlists
                }
+
+               if t == protocol.StopType {
+                       stop <- true
+               }
        }
 }
 
@@ -167,10 +172,11 @@ func filesWorker(cachePath string, ch chan []protocol.FileSpec) {
        }
 }
 
-func playlistWorker(ch <-chan []protocol.PlaylistSpec) {
+func playlistWorker(ch <-chan []protocol.PlaylistSpec, stop <-chan bool) {
        var specs []protocol.PlaylistSpec
        isPlaying := false
        playbackFinished := make(chan error)
+       cancel := make(chan bool)
        nextId := 0
        var timer *time.Timer
 
@@ -187,14 +193,20 @@ func playlistWorker(ch <-chan []protocol.PlaylistSpec) {
                case <-playbackFinished:
                        isPlaying = false
                        doNext = true
+                       cancel = make(chan bool)
                case <-timerCh:
                        timer = nil
                        isPlaying = true
                        for _, v := range specs {
                                if v.Id == nextId {
-                                       go playPlaylist(v, playbackFinished)
+                                       go playPlaylist(v, playbackFinished, cancel)
                                }
                        }
+               case <-stop:
+                       if isPlaying {
+                               log.Println("Cancelling playlist in progress")
+                               cancel <- true
+                       }
                }
 
                if doNext && !isPlaying {
@@ -231,10 +243,10 @@ func playlistWorker(ch <-chan []protocol.PlaylistSpec) {
        }
 }
 
-func playPlaylist(playlist protocol.PlaylistSpec, playbackFinished chan<- error) {
-       // TODO: possibility of on-demand cancellation
+func playPlaylist(playlist protocol.PlaylistSpec, playbackFinished chan<- error, cancel <-chan bool) {
        startTime := time.Now()
        log.Println("Beginning playback of playlist", playlist.Name)
+entries:
        for _, p := range playlist.Entries {
                // delay
                var duration time.Duration
@@ -248,7 +260,11 @@ func playPlaylist(playlist protocol.PlaylistSpec, playbackFinished chan<- error)
                        Seconds:  int(duration.Seconds()),
                        Filename: p.Filename,
                }
-               <-time.After(duration)
+               select {
+               case <-time.After(duration):
+               case <-cancel:
+                       break entries
+               }
 
                statusCollector.PlaylistBeginWaitForChannel <- BeginWaitForChannelStatus{
                        Playlist: playlist.Name,
@@ -297,7 +313,12 @@ func playPlaylist(playlist protocol.PlaylistSpec, playbackFinished chan<- error)
                        })))
                }
 
-               <-done
+               select {
+               case <-done:
+               case <-cancel:
+                       ptt.DisengagePTT()
+                       break entries
+               }
                ptt.DisengagePTT()
        }
        log.Println("Playlist finished", playlist.Name)