Fix enqueuing and song skip playback issues

Cargo.lock

@@ -868,9 +868,9 @@ dependencies = [
 
 [[package]]
 name = "rusqlite"
-version = "0.26.1"
+version = "0.26.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a82b0b91fad72160c56bf8da7a549b25d7c31109f52cc1437eac4c0ad2550a7"
+checksum = "4ba4d3462c8b2e4d7f4fcfcf2b296dc6b65404fbbc7b63daa37fd485c149daf7"
 dependencies = [
  "bitflags",
  "fallible-iterator",

mps-player/src/player.rs

@@ -1,7 +1,7 @@
 use std::io;
 use std::fs;
 
-use rodio::{decoder::Decoder, OutputStream, Sink};
+use rodio::{decoder::Decoder, OutputStream, Sink, OutputStreamHandle};
 
 use m3u8_rs::{MediaPlaylist, MediaSegment};
 
@@ -14,6 +14,7 @@ pub struct MpsPlayer<T: MpsTokenReader> {
     sink: Sink,
     #[allow(dead_code)]
     output_stream: OutputStream, // this is required for playback, so it must live as long as this struct instance
+    output_handle: OutputStreamHandle,
 }
 
 impl<T: MpsTokenReader> MpsPlayer<T> {
@@ -23,6 +24,7 @@ impl<T: MpsTokenReader> MpsPlayer<T> {
             runner: runner,
             sink: Sink::try_new(&output_handle).map_err(PlaybackError::from_err)?,
             output_stream: stream,
+            output_handle: output_handle
         })
     }
 
@@ -53,7 +55,7 @@ impl<T: MpsTokenReader> MpsPlayer<T> {
                     let stream = io::BufReader::new(file);
                     let source = Decoder::new(stream).map_err(PlaybackError::from_err)?;
                     self.sink.append(source);
-                    self.sink.play(); // idk if this is necessary
+                    //self.sink.play(); // idk if this is necessary
                     Ok(())
                 },
                 Err(e) => Err(PlaybackError::from_err(e))
@@ -64,20 +66,22 @@ impl<T: MpsTokenReader> MpsPlayer<T> {
 
     pub fn enqueue(&mut self, count: usize) -> Result<(), PlaybackError> {
         let mut items_left = count;
+        if items_left == 0 { return Ok(()); }
         for item in &mut self.runner {
-            if items_left == 0 { return Ok(()); }
             match item {
                 Ok(music) => {
+                    //println!("Enqueuing {}", music.filename);
                     let file = fs::File::open(music.filename).map_err(PlaybackError::from_err)?;
                     let stream = io::BufReader::new(file);
                     let source = Decoder::new(stream).map_err(PlaybackError::from_err)?;
                     self.sink.append(source);
-                    self.sink.play(); // idk if this is necessary
+                    //self.sink.play(); // idk if this is necessary
                     Ok(())
                 },
                 Err(e) => Err(PlaybackError::from_err(e))
             }?;
             items_left -= 1;
+            if items_left == 0 { break; }
         }
         Ok(())
     }
@@ -102,6 +106,10 @@ impl<T: MpsTokenReader> MpsPlayer<T> {
         self.sink.len()
     }
 
+    pub fn empty(&self) -> bool {
+        self.sink.empty()
+    }
+
     pub fn save_m3u8<W: io::Write>(&mut self, w: &mut W) -> Result<(), PlaybackError> {
         let mut playlist = MediaPlaylist {
             version: 6,
@@ -133,6 +141,20 @@ impl<T: MpsTokenReader> MpsPlayer<T> {
     pub fn set_volume(&self, volume: f32) {
         self.sink.set_volume(volume);
     }
+
+    pub fn new_sink(&mut self) -> Result<(), PlaybackError> {
+        let is_paused = self.sink.is_paused();
+        let volume = self.sink.volume();
+
+        self.stop();
+        self.sink = Sink::try_new(&self.output_handle).map_err(PlaybackError::from_err)?;
+
+        if is_paused {
+            self.sink.pause();
+        }
+        self.sink.set_volume(volume);
+        Ok(())
+    }
 }
 
 #[cfg(test)]

mps-player/src/player_wrapper.rs

@@ -6,8 +6,6 @@ use mps_interpreter::tokens::MpsTokenReader;
 use super::MpsPlayer;
 use super::PlaybackError;
 
-const DEFAULT_QUEUE_SIZE: usize = 1;
-
 pub struct MpsPlayerServer<T: MpsTokenReader> {
     player: MpsPlayer<T>,
     control: Receiver<ControlAction>,
@@ -25,29 +23,23 @@ impl<T: MpsTokenReader> MpsPlayerServer<T> {
 
     fn run_loop(&mut self) {
         // this can panic since it's not on the main thread
-        if let Err(e) = self.player.enqueue_all() {
+        // initial queue full
+        if let Err(e) = self.player.enqueue(1) {
             self.event.send(PlayerAction::Exception(e)).unwrap();
         }
         loop {
             let command = self.control.recv().unwrap();
 
-            // keep queue full
+            let mut is_exiting = false;
-            if self.player.queue_len() < DEFAULT_QUEUE_SIZE {
-                if let Err(e) = self.player.enqueue(DEFAULT_QUEUE_SIZE - self.player.queue_len()) {
-                    self.event.send(PlayerAction::Exception(e)).unwrap();
-                }
-                if self.player.queue_len() == 0 { // no more music to add
-                    self.event.send(PlayerAction::End).unwrap();
-                }
-            }
 
             // process command
-            let mut is_exiting = false;
             match command {
                 ControlAction::Next{..} => {
-                    if self.player.queue_len() <= 1 {
+                    //println!("Executing next command (queue_len: {})", self.player.queue_len());
-                        self.player.stop();
+                    if let Err(e) = self.player.new_sink() {
-                        //self.player.resume();
+                        self.event.send(PlayerAction::Exception(e)).unwrap();
+                    }
+                    if !self.player.is_paused() {
                         self.player.enqueue(1).unwrap();
                     }
                 },
@@ -76,12 +68,24 @@ impl<T: MpsTokenReader> MpsPlayerServer<T> {
                     self.player.set_volume((volume as f32) / (u32::MAX as f32));
                 }
             }
+
+            // keep queue full (while playing music)
+            if self.player.queue_len() == 0 && !self.player.is_paused() && !is_exiting {
+                if let Err(e) = self.player.enqueue(1) {
+                    self.event.send(PlayerAction::Exception(e)).unwrap();
+                }
+                if self.player.queue_len() == 0  { // no more music to add
+                    is_exiting = true;
+                }
+            }
+
             if command.needs_ack() {
                 self.event.send(PlayerAction::Acknowledge(command)).unwrap();
             }
 
             if is_exiting { break; }
         }
+        self.event.send(PlayerAction::End).unwrap();
     }
 
     pub fn spawn<F: FnOnce() -> MpsPlayer<T> + Send + 'static>(
@@ -111,7 +115,7 @@ impl<T: MpsTokenReader> MpsPlayerServer<T> {
 
 /// Action the controller wants the player to perform
 #[allow(dead_code)]
-#[derive(Clone, PartialEq, Eq)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum ControlAction {
     Next{ack: bool},
     Previous{ack: bool},
@@ -143,7 +147,7 @@ impl ControlAction {
 }
 
 /// Action the player has performed/encountered
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum PlayerAction {
     Acknowledge(ControlAction),
     Exception(PlaybackError),

src/main.rs

@@ -13,11 +13,17 @@ fn play_cursor() -> Result<(), PlaybackError> {
 fn main() {
     //play_cursor().unwrap();
     let ctrl = MpsController::create(|| {
-        let cursor = io::Cursor::<&'static str>::new("sql(`SELECT * FROM songs JOIN artists ON songs.artist = artists.artist_id WHERE artists.name like 'thundercat'`);");
+        //let cursor = io::Cursor::<&'static str>::new("sql(`SELECT * FROM songs JOIN artists ON songs.artist = artists.artist_id WHERE artists.name like 'thundercat'`);");
+        let cursor = io::Cursor::<&'static str>::new(
+        "sql(`SELECT * FROM songs JOIN artists ON songs.artist = artists.artist_id WHERE artists.name like 'thundercat'`);
+        artist(`gwen`);"
+        );
         let runner = MpsRunner::with_stream(cursor);
-        MpsPlayer::new(runner).unwrap()
+        let player = MpsPlayer::new(runner).unwrap();
+        player.set_volume(0.8);
+        player
     });
 
     ctrl.wait_for_done().unwrap();
-    ctrl.exit().unwrap();
+    //ctrl.exit().unwrap(); // don't use both
 }