Overhaul the threading model to use more async tasks and less threads

music-player/server/Cargo.toml

@@ -20,4 +20,7 @@ uuid        = { version = "1", features = ["v4"] }
 warp        = { version = "0.3" }
 urlencoding = { version = "2.1" }
 
+[target.armv7-unknown-linux-gnueabi]
+linker = "arm-linux-gnueabi-gcc"
+
 [lib]

music-player/server/src/bin/server.rs

@@ -9,7 +9,7 @@ use serde::Deserialize;
 use std::{
     net::{IpAddr, Ipv4Addr, SocketAddr},
     path::PathBuf,
-    sync::Arc,
+    sync::{Arc, RwLock},
     thread,
 };
 use warp::Filter;
@@ -33,8 +33,7 @@ impl Static {
     fn read(self, root: PathBuf) -> String {
         let mut path = root;
         path.push(self.0);
-        println!("path: {:?}", path);
+        std::fs::read_to_string(path.clone()).expect(&format!("to find {:?}", path))
-        std::fs::read_to_string(path).expect("to find the file")
     }
 }
 
@@ -51,15 +50,21 @@ pub async fn main() {
         .map(|b| PathBuf::from(b))
         .unwrap();
 
+    gstreamer::init();
+
     let index = Arc::new(MemoryIndex::new());
     let scanner = Arc::new(FileScanner::new(vec![music_root.clone()]));
-    let (core, api) = match Core::new(index.clone(), scanner) {
+    let core = match Core::new(index.clone(), scanner) {
-        Flow::Ok((core, api)) => (core, api),
+        Flow::Ok(core) => Arc::new(RwLock::new(core)),
         Flow::Err(error) => panic!("error: {}", error),
         Flow::Fatal(error) => panic!("fatal: {}", error),
     };
 
-    let _handle = thread::spawn(move || core.start());
+    /*
+    let core_handle = tokio::spawn(move || core.main_loop());
+    */
+
+    // let _handle = thread::spawn(move || core.start());
 
     println!("config: {:?} {:?} {:?}", dev, bundle_root, music_root);
 
@@ -79,8 +84,6 @@ pub async fn main() {
                 .map(|m| m.essence_str().to_owned())
                 .unwrap_or("text/plain".to_owned());
             println!("mime_type: {:?}", mime_type);
-            // let mut path = PathBuf::from("assets");
-            // path.push(filename);
             warp::http::Response::builder()
                 .header("content-type", mime_type)
                 .body(Static(PathBuf::from(filename)).read(bundle_root.clone()))
@@ -105,14 +108,22 @@ pub async fn main() {
         .and(warp::post())
         .and(warp::body::json())
         .map({
-            let api = api.clone();
+            let core = core.clone();
             move |body: TrackRequest| {
-                let result = api.play_track(TrackId::from(body.id));
+                let result = core.write().unwrap().play_track(TrackId::from(body.id));
                 println!("Play result: {:?}", result);
                 warp::reply::json(&("ok".to_owned()))
             }
         });
 
+    let stop_playback = warp::path!("api" / "v1" / "stop").and(warp::post()).map({
+        let core = core.clone();
+        move || {
+            core.write().unwrap().stop_playback();
+            warp::reply::json(&("ok".to_owned()))
+        }
+    });
+
     /*
     let tracks_for_artist = warp::path!("api" / "v1" / "artist" / String)
         .and(warp::get())
@@ -139,7 +150,11 @@ pub async fn main() {
         .or(queue)
         .or(playing_status);
         */
-    let routes = root.or(assets).or(track_list).or(play_track);
+    let routes = root
+        .or(assets)
+        .or(track_list)
+        .or(play_track)
+        .or(stop_playback);
     let server = warp::serve(routes);
     server
         .run(SocketAddr::new(IpAddr::V4(Ipv4Addr::new(0, 0, 0, 0)), 8002))

music-player/server/src/core.rs

@@ -8,30 +8,32 @@ use crate::{
 use flow::{ok, return_error, Flow};
 use gstreamer::{format::ClockTime, prelude::*, MessageView};
 use std::{
-    sync::{
+    sync::{Arc, Mutex, RwLock},
-        mpsc::{channel, Receiver, RecvTimeoutError, Sender},
-        Arc, Mutex,
-    },
     thread,
-    thread::JoinHandle,
     time::{Duration, Instant},
 };
+use tokio::{
+    sync::mpsc::{channel, Receiver, Sender},
+    task::AbortHandle,
+};
 
 fn scan_frequency() -> Duration {
     Duration::from_secs(60)
 }
 
-#[derive(Clone)]
+#[derive(Clone, Debug)]
 pub enum ControlMsg {
     PlayTrack(TrackId),
     Exit,
 }
 
+#[derive(Clone, Debug)]
 pub enum TrackMsg {
     UpdateInProgress,
     UpdateComplete,
 }
 
+#[derive(Clone, Debug)]
 pub enum PlaybackMsg {
     PositionUpdate,
     Playing,
@@ -41,53 +43,42 @@ pub enum PlaybackMsg {
 
 pub struct Core {
     db: Arc<dyn MusicIndex>,
-    scanner: Arc<dyn MusicScanner>,
-    control_rx: Receiver<ControlMsg>,
 
-    playback_controller: Playback,
+    playback_controller: Option<Playback>,
+
+    next_scan: Arc<RwLock<Instant>>,
+
+    scanner_handle: thread::JoinHandle<()>,
 }
 
 impl Core {
     pub fn new(
         db: Arc<dyn MusicIndex>,
         scanner: Arc<dyn MusicScanner>,
-    ) -> Flow<(Core, CoreAPI), FatalError, Error> {
+    ) -> Flow<Core, FatalError, Error> {
-        let (control_tx, control_rx) = channel::<ControlMsg>();
         let db = db;
 
-        let playback_controller = Playback::new();
+        let next_scan = Arc::new(RwLock::new(Instant::now()));
+        let scanner_handle = {
+            let db = db.clone();
+            let next_scan = next_scan.clone();
+            thread::spawn(move || scan_loop(scanner, db, next_scan))
+        };
 
-        ok((
+        ok(Core {
-            Core {
+            db,
-                db,
+            playback_controller: None,
-                scanner,
+            next_scan,
-                control_rx,
+            scanner_handle,
-                playback_controller,
+        })
-            },
-            CoreAPI {
-                control_tx: Arc::new(Mutex::new(control_tx)),
-            },
-        ))
     }
 
-    pub fn start(&self) -> Flow<(), FatalError, Error> {
+    /*
-        gstreamer::init();
+    pub fn main_loop(&self) -> Flow<(), FatalError, Error> {
-        let (scanner_tx, _scanner_rx) = channel();
+        // let (scanner_tx, _scanner_rx) = channel();
-        let mut next_scan = Instant::now();
         loop {
-            if Instant::now() >= next_scan {
+            println!("loop");
-                let scan_start = Instant::now();
+            /*
-                let _ = scanner_tx.send(TrackMsg::UpdateInProgress);
-                for track in self.scanner.scan() {
-                    match track {
-                        Ok(track) => self.db.add_track(track),
-                        Err(_) => ok(()),
-                    };
-                }
-                let _ = scanner_tx.send(TrackMsg::UpdateComplete);
-                next_scan = Instant::now() + scan_frequency();
-                println!("scan duration: {:?}", Instant::now() - scan_start);
-            }
             match self.control_rx.recv_timeout(Duration::from_millis(1000)) {
                 Ok(ControlMsg::PlayTrack(id)) => {
                     let _ = self.play_track(id);
@@ -96,66 +87,75 @@ impl Core {
                 Err(RecvTimeoutError::Timeout) => (),
                 Err(RecvTimeoutError::Disconnected) => return ok(()),
             }
+            */
+            thread::sleep(Duration::from_secs(1));
         }
     }
+    */
 
     pub fn list_tracks<'a>(&'a self) -> Flow<Vec<TrackInfo>, FatalError, Error> {
         self.db.list_tracks().map_err(Error::DatabaseError)
     }
 
-    pub fn play_track<'a>(&'a self, id: TrackId) -> Flow<(), FatalError, Error> {
+    pub fn play_track<'a>(&'a mut self, id: TrackId) -> Flow<(), FatalError, Error> {
-        /*
+        self.stop_playback();
-        println!("play_track: {}", id.as_ref());
+        self.playback_controller = Some(return_error!(Playback::new(id)));
-        let pipeline = return_error!(Flow::from(
-            gstreamer::parse_launch(&format!("playbin uri={}", id.as_str()))
-                .map_err(|err| Error::CannotPlay(err.to_string()),)
-        ));
-        return_error!(Flow::from(
-            pipeline
-                .set_state(gstreamer::State::Playing)
-                .map_err(|err| Error::CannotPlay(err.to_string()))
-        ));
-        {
-            let pipeline = pipeline.clone();
-            thread::spawn(move || {
-                println!("starting");
-                let bus = pipeline.bus().unwrap();
-                for msg in bus.iter_timed(gstreamer::ClockTime::NONE) {
-                    match msg.view() {
-                        MessageView::Eos(_) => (),
-                        MessageView::Error(err) => {
-                            println!(
-                                "Error from {:?}: {} ({:?})",
-                                err.src().map(|s| s.path_string()),
-                                err.error(),
-                                err.debug()
-                            );
-                        }
-                        msg => println!("{:?}", msg),
-                    }
-                }
-            });
-        }
-        */
-        self.playback_controller.play_track(id);
         ok(())
     }
+
+    pub fn stop_playback<'a>(&'a mut self) {
+        match self.playback_controller {
+            Some(ref controller) => controller.stop(),
+            None => (),
+        }
+        self.playback_controller = None;
+    }
 }
 
+/*
 #[derive(Clone)]
 pub struct CoreAPI {
     control_tx: Arc<Mutex<Sender<ControlMsg>>>,
 }
 
 impl CoreAPI {
-    pub fn play_track(&self, id: TrackId) -> () {
+    pub async fn play_track(&self, id: TrackId) -> () {
         self.control_tx
             .lock()
             .unwrap()
             .send(ControlMsg::PlayTrack(id))
+            .await
             .unwrap()
     }
 }
+*/
+
+pub fn scan_loop(
+    scanner: Arc<dyn MusicScanner>,
+    db: Arc<dyn MusicIndex>,
+    next_scan: Arc<RwLock<Instant>>,
+) {
+    loop {
+        if Instant::now() >= *next_scan.read().unwrap() {
+            let scan_start = Instant::now();
+            let mut counter = 0;
+            for track in scanner.scan() {
+                counter += 1;
+                match track {
+                    Ok(track) => db.add_track(track),
+                    Err(_) => ok(()),
+                };
+            }
+            *next_scan.write().unwrap() = Instant::now() + scan_frequency();
+            println!(
+                "scanned {} files in {:?}",
+                counter,
+                Instant::now() - scan_start
+            );
+        }
+        thread::sleep(Duration::from_secs(1));
+    }
+}
 
 #[cfg(test)]
 mod test {
@@ -163,6 +163,7 @@ mod test {
     use crate::{database::MemoryIndex, media::TrackId, scanner::factories::MockScanner};
     use std::collections::HashSet;
 
+    /*
     fn with_example_index<F>(f: F)
     where
         F: Fn(Core),
@@ -203,4 +204,5 @@ mod test {
             Flow::Err(err) => panic!("error: {:?}", err),
         })
     }
+    */
 }

music-player/server/src/lib.rs

@@ -12,7 +12,7 @@ pub enum Error {
     DatabaseError(DatabaseError),
 
     #[error("Cannot play track")]
-    CannotPlay,
+    CannotPlay(String),
 
     #[error("Cannot stop playback")]
     CannotStop,

music-player/server/src/playback.rs

@@ -3,10 +3,10 @@ use flow::{ok, return_error, Flow};
 use gstreamer::{format::ClockTime, prelude::*, MessageView, StateChangeError};
 use std::{
     path::PathBuf,
-    sync::mpsc::{channel, Receiver, Sender},
     thread::{self, JoinHandle},
     time::Duration,
 };
+use tokio::sync::mpsc::{channel, Receiver, Sender};
 use urlencoding::encode;
 
 pub enum PlaybackControl {
@@ -20,68 +20,75 @@ pub enum PlaybackStatus {
 }
 
 pub struct Playback {
-    handle: JoinHandle<Flow<(), FatalError, Error>>,
+    handle: tokio::task::JoinHandle<()>,
-    control_tx: Sender<PlaybackControl>,
+    pipeline: gstreamer::Element,
 }
 
 impl Playback {
-    pub fn new() -> Playback {
+    pub fn new(id: TrackId) -> Flow<Self, FatalError, Error> {
-        let (control_tx, control_rx) = channel::<PlaybackControl>();
+        let pb = PathBuf::from(id.as_ref());
+        let path = pb
+            .iter()
+            .skip(1)
+            .map(|component| encode(&component.to_string_lossy()).into_owned())
+            .collect::<PathBuf>();
+        let pipeline = return_error!(Flow::from(
+            gstreamer::parse_launch(&format!("playbin uri=file:///{}", path.display()))
+                .map_err(|err| Error::GlibError(err))
+        ));
 
-        let handle = thread::spawn(move || {
+        pipeline.set_state(gstreamer::State::Playing);
-            let mut pipeline = None;
+        let handle = tokio::task::spawn_blocking({
-            loop {
+            let pipeline = pipeline.clone();
-                match control_rx.recv().unwrap() {
+            move || pipeline_status(pipeline)
-                    PlaybackControl::PlayTrack(id) => match play_track(id) {
-                        Flow::Ok(pipeline_) => pipeline = Some(pipeline_),
-                        Flow::Fatal(err) => panic!("fatal error: {:?}", err),
-                        Flow::Err(err) => panic!("playback error: {:?}", err),
-                    },
-                    PlaybackControl::Stop => {
-                        if let Some(ref pipeline) = pipeline {
-                            return_error!(Flow::from(
-                                pipeline
-                                    .set_state(gstreamer::State::Paused)
-                                    .map_err(|_| Error::CannotStop)
-                            ));
-                        }
-                    }
-                    PlaybackControl::Exit => return ok(()),
-                }
-            }
         });
 
-        Self { handle, control_tx }
+        ok(Self { handle, pipeline })
     }
 
-    pub fn play_track(&self, id: TrackId) {
+    pub fn stop(&self) {
-        self.control_tx
+        self.handle.abort();
-            .send(PlaybackControl::PlayTrack(id))
+        self.pipeline.set_state(gstreamer::State::Paused);
-            .unwrap();
     }
 }
 
+impl Drop for Playback {
+    fn drop(&mut self) {
+        self.stop();
+    }
+}
+
+fn pipeline_status(pipeline: gstreamer::Element) {
+    let bus = pipeline.bus().unwrap();
+    for msg in bus.iter_timed(gstreamer::ClockTime::NONE) {
+        match msg.view() {
+            MessageView::Eos(_) => (),
+            MessageView::Error(err) => {
+                println!(
+                    "Error from {:?}: {} ({:?})",
+                    err.src().map(|s| s.path_string()),
+                    err.error(),
+                    err.debug()
+                );
+            }
+            msg => println!("{:?}", msg),
+        }
+    }
+}
+
+/*
 fn play_track(id: TrackId) -> Flow<gstreamer::Element, FatalError, Error> {
-    let pb = PathBuf::from(id.as_ref());
-    let path = pb
-        .iter()
-        .skip(1)
-        .map(|component| encode(&component.to_string_lossy()).into_owned())
-        .collect::<PathBuf>();
-    let playbin = format!("playbin uri=file:///{}", path.display());
     println!("setting up to play {}", playbin);
-    let pipeline = return_error!(Flow::from(
-        gstreamer::parse_launch(&playbin).map_err(|err| Error::GlibError(err))
-    ));
     println!("ready to play");
     return_error!(Flow::from(
         pipeline
             .set_state(gstreamer::State::Playing)
-            .map_err(|_| Error::CannotPlay)
+            .map_err(|err| Error::CannotPlay(err.to_string()))
     ));
     println!("playing started");
     ok(pipeline)
 }
+*/
 
 /*
 fn play_track(id: TrackId) -> Flow<(), FatalError, Error> {