feat: add queue and interval

Cargo.toml

@@ -15,6 +15,8 @@ lazy_static = "1.4"
 clap = { version = "4.1", features = ["derive"] }
 thiserror = "1.0"
 enum-display-derive = "0.1"
+queues = "1.1.0"
+duration-str = { version = "0.5.1", features = ["serde"] }
 
 [target.'cfg(target_os = "linux")'.dependencies]
 alsa = "0.7.0"

src/config/device.rs

@@ -1,3 +1,5 @@
+use std::time::Duration;
+
 use crate::event::Event;
 use crate::util;
 use crate::Error;
@@ -19,6 +21,8 @@ pub struct DeviceConfig {
     pub connect: Option<Vec<RunConfig>>,
     pub disconnect: Option<Vec<RunConfig>>,
     pub events: Option<Vec<EventConfig>>,
+    pub queue_length: usize,
+    pub interval: Duration,
 }
 
 impl DeviceConfig {
@@ -66,6 +70,8 @@ impl TryFrom<DeviceConfigSerializer> for DeviceConfig {
             connect:    util::map_opt_tryfrom(v.connect)?,
             disconnect: util::map_opt_tryfrom(v.disconnect)?,
             events:     util::map_opt_tryfrom(v.events)?,
+            queue_length: v.queue_length.unwrap_or(256),
+            interval: v.interval.map(|x| x.unwrap()).unwrap_or_else(|| Duration::new(0, 0)),
         })
     }
 }

src/config/serializer/device.rs

@@ -1,7 +1,26 @@
+use std::time::Duration;
+
 use super::{RunConfigSerializer,EventConfigSerializer};
 
+use duration_str::deserialize_duration;
 use serde::Deserialize;
 
+#[derive(Debug,Clone,Deserialize)]
+#[serde(untagged)]
+pub enum DurationWrapper {
+    #[serde(deserialize_with = "deserialize_duration")]
+    Some(Duration),
+}
+
+impl DurationWrapper {
+    pub fn unwrap(self) -> Duration
+    {
+        match self {
+            DurationWrapper::Some(v) => v,
+        }
+    }
+}
+
 #[derive(Deserialize,Debug,Clone)]
 #[serde(deny_unknown_fields)]
 pub struct DeviceConfigSerializer {
@@ -12,4 +31,6 @@ pub struct DeviceConfigSerializer {
     pub disconnect: Option<Vec<RunConfigSerializer>>,
     pub events: Option<Vec<EventConfigSerializer>>,
     pub max_connections: Option<u32>,
+    pub queue_length: Option<usize>,
+    pub interval: Option<DurationWrapper>,
 }

src/event.rs

@@ -87,6 +87,16 @@ pub struct Event<'a> {
     pub timestamp: Option<SystemTime>,
 }
 
+#[derive(Debug,Clone,Default)]
+pub struct EventBuf {
+    pub r#type: EventType,
+    pub channel: u8,
+    pub id: u8,
+    pub value: u16,
+    pub raw: Vec<u8>,
+    pub timestamp: Option<SystemTime>,
+}
+
 pub struct EventEnv {
     pub channel: String,
     pub id: String,
@@ -106,6 +116,32 @@ struct EventEnvRef<'a> {
     pub value: &'a str,
 }
 
+impl EventBuf {
+    pub fn as_event(&self) -> Event {
+        Event {
+            r#type: self.r#type,
+            channel: self.channel,
+            id: self.id,
+            value: self.value,
+            raw: &self.raw[..],
+            timestamp: self.timestamp,
+        }
+    }
+}
+
+impl Into<EventBuf> for Event<'_> {
+    fn into(self) -> EventBuf {
+        EventBuf {
+            r#type: self.r#type,
+            channel: self.channel,
+            id: self.id,
+            value: self.value,
+            raw: Vec::from(self.raw),
+            timestamp: self.timestamp,
+        }
+    }
+}
+
 impl From<u8> for EventType {
     fn from(v: u8) -> Self {
         if ! (0b1000..=0b1111).contains(&v) {

src/midi/mod.rs

@@ -1,5 +1,7 @@
 pub mod alsa;
 
+use queues::{CircularBuffer, IsQueue};
+
 use crate::config::device::Identifier;
 use crate::midi::alsa::MidiInputAlsa;
 use crate::Error;
@@ -8,10 +10,11 @@ extern crate libc;
 
 use crate::config::DeviceConfig;
 use crate::eventmap::EventMap;
-use crate::event::Event;
+use crate::event::{Event, EventBuf};
 
-use std::time::SystemTime;
-use std::sync::mpsc;
+use std::thread;
+use std::time::{SystemTime, Instant};
+use std::sync::{mpsc, Mutex, Arc};
 
 #[derive(Eq,PartialEq,Debug,Clone)]
 pub struct MidiPort<T>{
@@ -161,9 +164,9 @@ impl MidiHandler {
         r
     }
 
-    pub fn run(&mut self, eventmap: &EventMap, (rs,ts): (mpsc::Receiver<bool>, mpsc::Sender<bool>)) -> Result<(), Error>  {
+    pub fn run(&mut self, conf: &DeviceConfig, eventmap: &EventMap, (rs,ts): (mpsc::Receiver<bool>, mpsc::Sender<bool>)) -> Result<(), Error>  {
         handler_fcall!{
-            self, handle_inputport ,(eventmap,(rs,ts)),
+            self, handle_inputport, (conf, eventmap,(rs,ts)),
             ALSA
         }
     }
@@ -189,19 +192,57 @@ where T: MidiInput<A>
     input.ports_handle()
 }
 
-fn handle_inputport<T>(input: &mut T, (eventmap, (rs, ts)): (&EventMap, (mpsc::Receiver<bool>, mpsc::Sender<bool>))) -> Result<(), Error>
-where T: MidiInputHandler
+fn handle_inputport<T>(input: &mut T, (conf, eventmap, (rs, ts)): (&DeviceConfig, &EventMap, (mpsc::Receiver<bool>, mpsc::Sender<bool>))) -> Result<(), Error>
+where T: MidiInputHandler + Send
 {
-    input.handle_input(|t,m,_| {
-        let mut event = Event::from(m);
-        event.timestamp = t;
-        match eventmap.run_event(&event) {
-            Ok(_) => (),
-            Err(e) => {
-                eprintln!("ERROR: error on run: {}", e)
-            },
-        }
-    }, (rs,ts), ())?;
+    thread::scope(|s| -> Result<(), Error> {
+
+        // parking signal for runner, true = stop
+        let (pts,prs) = mpsc::channel::<bool>();
+
+        let evq = Arc::new(Mutex::new(CircularBuffer::<EventBuf>::new(conf.queue_length)));
+
+        // background execution loop
+        let rq = evq.clone();
+        let exec_thread = s.spawn(move || -> Result<(),Error> {
+            loop {
+                if prs.recv()? {
+                    break;
+                }
+                loop {
+                    // nest the lock into a scope to release it before run
+                    let (ev,start): (EventBuf,Instant) = {
+                        let mut evq = rq.lock().unwrap();
+                        if evq.size() > 0 {
+                            (evq.remove().unwrap(), Instant::now())
+                        } else {
+                            break;
+                        }
+                    };
+                    eventmap.run_event(&ev.as_event()).unwrap_or_else(|e| eprintln!("ERROR: error on run: {}", e) );
+                    let elapsed_time = start.elapsed();
+                    if elapsed_time < conf.interval {
+                        thread::sleep(conf.interval - elapsed_time);
+                    }
+                }
+            }
+            Ok(())
+        });
+
+        input.handle_input(|t,m,(evq,pts)| {
+            let mut event: EventBuf = Event::from(m).into();
+            event.timestamp = t;
+            let mut evq = evq.lock().unwrap();
+            evq.add(event).unwrap();
+            pts.send(false).expect("unexpected write error");
+        }, (rs,ts), (evq,pts.clone()))?;
+
+        pts.send(true).expect("unexpected write error");
+        let _ = exec_thread.join();
+
+        Ok(())
+
+    })?;
     Ok(())
 }
 

src/run.rs

@@ -74,7 +74,7 @@ fn try_connect_process<'a>(
             let mm = m.as_ref().map(Arc::clone);
             let t = s.spawn( move || {
                 dev.run_connect().unwrap();
-                c.run(eventmap, (srs,nsts)).unwrap();
+                c.run(dev, eventmap, (srs,nsts)).unwrap();
                 if let Some(m) = mm {
                     let mut m = m.lock().unwrap();
                     m.0 -= 1;

test/vmpk.yml

@@ -1,6 +1,8 @@
 devices:
   - name: 'VMPK'
     max_connections: 1
+    queue_length: 3
+    interval: 100ms
     connect: 
       - args: [ "sh", "-c", "echo Hello world!" ]
     disconnect: