break up into crates again

engine/jack.rs

@@ -0,0 +1,222 @@
+use crate::*;
+pub use ::jack::{*, contrib::{*, ClosureProcessHandler}};
+/// Wraps [JackState] and through it [jack::Client] when connected.
+#[derive(Clone, Debug, Default)]
+pub struct Jack<'j>(Arc<RwLock<JackState<'j>>>);
+/// Implement [Jack] constructor and methods
+impl<'j> Jack<'j> {
+    /// Register new [Client] and wrap it for shared use.
+    pub fn new_run <T: HasJack<'j> + Audio + Send + Sync + 'static> (
+        name: &impl AsRef<str>,
+        init: impl FnOnce(Jack<'j>)->Usually<T>
+    ) -> Usually<Arc<RwLock<T>>> {
+        Jack::new(name)?.run(init)
+    }
+    pub fn new (name: &impl AsRef<str>) -> Usually<Self> {
+        let client = Client::new(name.as_ref(), ClientOptions::NO_START_SERVER)?.0;
+        Ok(Jack(Arc::new(RwLock::new(JackState::Inactive(client)))))
+    }
+    pub fn run <T: HasJack<'j> + Audio + Send + Sync + 'static>
+        (self, init: impl FnOnce(Self)->Usually<T>) -> Usually<Arc<RwLock<T>>>
+    {
+        let client_state = self.0.clone();
+        let app: Arc<RwLock<T>> = Arc::new(RwLock::new(init(self)?));
+        let mut state = Activating;
+        std::mem::swap(&mut*client_state.write().unwrap(), &mut state);
+        if let Inactive(client) = state {
+            let client = client.activate_async(
+                // This is the misc notifications handler. It's a struct that wraps a [Box]
+                // which performs type erasure on a callback that takes [JackEvent], which is
+                // one of the available misc notifications.
+                Notifications(Box::new({
+                    let app = app.clone();
+                    move|event|(&mut*app.write().unwrap()).handle(event)
+                }) as BoxedJackEventHandler),
+                // This is the main processing handler. It's a struct that wraps a [Box]
+                // which performs type erasure on a callback that takes [Client] and [ProcessScope]
+                // and passes them down to the `app`'s `process` callback, which in turn
+                // implements audio and MIDI input and output on a realtime basis.
+                ClosureProcessHandler::new(Box::new({
+                    let app = app.clone();
+                    move|c: &_, s: &_|if let Ok(mut app) = app.write() {
+                        app.process(c, s)
+                    } else {
+                        Control::Quit
+                    }
+                }) as BoxedAudioHandler),
+            )?;
+            *client_state.write().unwrap() = Active(client);
+        } else {
+            unreachable!();
+        }
+        Ok(app)
+    }
+    /// Run something with the client.
+    pub fn with_client <T> (&self, op: impl FnOnce(&Client)->T) -> T {
+        match &*self.0.read().unwrap() {
+            Inert            => panic!("jack client not activated"),
+            Inactive(client) => op(client),
+            Activating       => panic!("jack client has not finished activation"),
+            Active(client)   => op(client.as_client()),
+        }
+    }
+}
+impl<'j> HasJack<'j> for Jack<'j> {
+    fn jack (&self) -> &Jack<'j> {
+        self
+    }
+}
+impl<'j> HasJack<'j> for &Jack<'j> {
+    fn jack (&self) -> &Jack<'j> {
+        self
+    }
+}
+/// This is a connection which may be [Inactive], [Activating], or [Active].
+/// In the [Active] and [Inactive] states, [JackState::client] returns a
+/// [jack::Client], which you can use to talk to the JACK API.
+#[derive(Debug, Default)]
+pub enum JackState<'j> {
+    /// Unused
+    #[default] Inert,
+    /// Before activation.
+    Inactive(Client),
+    /// During activation.
+    Activating,
+    /// After activation. Must not be dropped for JACK thread to persist.
+    Active(DynamicAsyncClient<'j>),
+}
+/// Things that can provide a [jack::Client] reference.
+pub trait HasJack<'j>: Send + Sync {
+    /// Return the internal [jack::Client] handle
+    /// that lets you call the JACK API.
+    fn jack (&self) -> &Jack<'j>;
+    fn with_client <T> (&self, op: impl FnOnce(&Client)->T) -> T {
+        self.jack().with_client(op)
+    }
+    fn port_by_name (&self, name: &str) -> Option<Port<Unowned>> {
+        self.with_client(|client|client.port_by_name(name))
+    }
+    fn port_by_id (&self, id: u32) -> Option<Port<Unowned>> {
+        self.with_client(|c|c.port_by_id(id))
+    }
+    fn register_port <PS: PortSpec + Default> (&self, name: impl AsRef<str>) -> Usually<Port<PS>> {
+        self.with_client(|client|Ok(client.register_port(name.as_ref(), PS::default())?))
+    }
+    fn sync_lead (&self, enable: bool, callback: impl Fn(TimebaseInfo)->Position) -> Usually<()> {
+        if enable {
+            self.with_client(|client|match client.register_timebase_callback(false, callback) {
+               Ok(_) => Ok(()),
+                Err(e) => Err(e)
+            })?
+        }
+        Ok(())
+    }
+    fn sync_follow (&self, _enable: bool) -> Usually<()> {
+        // TODO: sync follow
+        Ok(())
+    }
+}
+/// Trait for thing that has a JACK process callback.
+pub trait Audio {
+    /// Handle a JACK event.
+    fn handle (&mut self, _event: JackEvent) {}
+    /// Projecss a JACK chunk.
+    fn process (&mut self, _: &Client, _: &ProcessScope) -> Control {
+        Control::Continue
+    }
+    /// The JACK process callback function passed to the server.
+    fn callback (
+        state: &Arc<RwLock<Self>>, client: &Client, scope: &ProcessScope
+    ) -> Control where Self: Sized {
+        if let Ok(mut state) = state.write() {
+            state.process(client, scope)
+        } else {
+            Control::Quit
+        }
+    }
+}
+/// Implement [Audio]: provide JACK callbacks.
+#[macro_export] macro_rules! audio {
+    (|
+        $self1:ident:
+        $Struct:ident$(<$($L:lifetime),*$($T:ident$(:$U:path)?),*>)?,$c:ident,$s:ident
+    |$cb:expr$(;|$self2:ident,$e:ident|$cb2:expr)?) => {
+        impl $(<$($L),*$($T $(: $U)?),*>)? Audio for $Struct $(<$($L),*$($T),*>)? {
+            #[inline] fn process (&mut $self1, $c: &Client, $s: &ProcessScope) -> Control { $cb }
+            $(#[inline] fn handle (&mut $self2, $e: JackEvent) { $cb2 })?
+        }
+    }
+}
+/// Event enum for JACK events.
+#[derive(Debug, Clone, PartialEq)] pub enum JackEvent {
+    ThreadInit,
+    Shutdown(ClientStatus, Arc<str>),
+    Freewheel(bool),
+    SampleRate(Frames),
+    ClientRegistration(Arc<str>, bool),
+    PortRegistration(PortId, bool),
+    PortRename(PortId, Arc<str>, Arc<str>),
+    PortsConnected(PortId, PortId, bool),
+    GraphReorder,
+    XRun,
+}
+/// Generic notification handler that emits [JackEvent]
+pub struct Notifications<T: Fn(JackEvent) + Send>(pub T);
+
+impl<T: Fn(JackEvent) + Send> NotificationHandler for Notifications<T> {
+    fn thread_init(&self, _: &Client) {
+        self.0(JackEvent::ThreadInit);
+    }
+    unsafe fn shutdown(&mut self, status: ClientStatus, reason: &str) {
+        self.0(JackEvent::Shutdown(status, reason.into()));
+    }
+    fn freewheel(&mut self, _: &Client, enabled: bool) {
+        self.0(JackEvent::Freewheel(enabled));
+    }
+    fn sample_rate(&mut self, _: &Client, frames: Frames) -> Control {
+        self.0(JackEvent::SampleRate(frames));
+        Control::Quit
+    }
+    fn client_registration(&mut self, _: &Client, name: &str, reg: bool) {
+        self.0(JackEvent::ClientRegistration(name.into(), reg));
+    }
+    fn port_registration(&mut self, _: &Client, id: PortId, reg: bool) {
+        self.0(JackEvent::PortRegistration(id, reg));
+    }
+    fn port_rename(&mut self, _: &Client, id: PortId, old: &str, new: &str) -> Control {
+        self.0(JackEvent::PortRename(id, old.into(), new.into()));
+        Control::Continue
+    }
+    fn ports_connected(&mut self, _: &Client, a: PortId, b: PortId, are: bool) {
+        self.0(JackEvent::PortsConnected(a, b, are));
+    }
+    fn graph_reorder(&mut self, _: &Client) -> Control {
+        self.0(JackEvent::GraphReorder);
+        Control::Continue
+    }
+    fn xrun(&mut self, _: &Client) -> Control {
+        self.0(JackEvent::XRun);
+        Control::Continue
+    }
+}
+
+/// This is a running JACK [AsyncClient] with maximum type erasure.
+/// It has one [Box] containing a function that handles [JackEvent]s,
+/// and another [Box] containing a function that handles realtime IO,
+/// and that's all it knows about them.
+pub type DynamicAsyncClient<'j>
+    = AsyncClient<DynamicNotifications<'j>, DynamicAudioHandler<'j>>;
+/// This is the notification handler wrapper for a boxed realtime callback.
+pub type DynamicAudioHandler<'j> =
+    ClosureProcessHandler<(), BoxedAudioHandler<'j>>;
+/// This is a boxed realtime callback.
+pub type BoxedAudioHandler<'j> =
+    Box<dyn FnMut(&Client, &ProcessScope) -> Control + Send + Sync + 'j>;
+/// This is the notification handler wrapper for a boxed [JackEvent] callback.
+pub type DynamicNotifications<'j> =
+    Notifications<BoxedJackEventHandler<'j>>;
+/// This is a boxed [JackEvent] callback.
+pub type BoxedJackEventHandler<'j> =
+    Box<dyn Fn(JackEvent) + Send + Sync + 'j>;
+use self::JackState::*;
+