refactor: reorganize channel modules and implement async/sync structures

src/sync/channel.rs

@@ -0,0 +1,214 @@
+use std::sync::atomic::{AtomicBool, Ordering};
+use std::sync::{Arc, Mutex};
+
+use crate::error::Error;
+use crate::sync::traits::{ChannelReceiver, ChannelSender};
+use crate::types::{ChannelState, Request, Response, ValueSource};
+
+/// The consumer side of the channel that requests values
+pub struct Sucker<T, ST, SR>
+where
+    ST: ChannelSender<Request>,
+    SR: ChannelReceiver<Response<T>>,
+{
+    request_tx: ST,
+    response_rx: SR,
+    closed: AtomicBool,
+    _phantom: std::marker::PhantomData<T>,
+}
+
+impl<T, ST, SR> Sucker<T, ST, SR>
+where
+    ST: ChannelSender<Request>,
+    SR: ChannelReceiver<Response<T>>,
+{
+    /// Create a new Sucker instance
+    pub(crate) fn new(request_tx: ST, response_rx: SR) -> Self {
+        Self {
+            request_tx,
+            response_rx,
+            closed: AtomicBool::new(false),
+            _phantom: std::marker::PhantomData,
+        }
+    }
+}
+
+/// The producer side of the channel that provides values
+pub struct Sourcer<T, SR, ST>
+where
+    SR: ChannelReceiver<Request>,
+    ST: ChannelSender<Response<T>>,
+{
+    request_rx: SR,
+    response_tx: ST,
+    state: ChannelState<T>,
+    _phantom: std::marker::PhantomData<T>,
+}
+
+impl<T, SR, ST> Sourcer<T, SR, ST>
+where
+    SR: ChannelReceiver<Request>,
+    ST: ChannelSender<Response<T>>,
+{
+    /// Create a new Sourcer instance
+    pub(crate) fn new(request_rx: SR, response_tx: ST, state: ChannelState<T>) -> Self {
+        Self {
+            request_rx,
+            response_tx,
+            state,
+            _phantom: std::marker::PhantomData,
+        }
+    }
+}
+
+impl<T, SR, ST> Sourcer<T, SR, ST>
+where
+    T: Send + 'static,
+    SR: ChannelReceiver<Request>,
+    ST: ChannelSender<Response<T>>,
+{
+    /// Set a fixed value
+    pub fn set_static(&self, val: T) -> Result<(), Error>
+    where
+        T: Clone,
+    {
+        self.state.swap(Arc::new(ValueSource::Static {
+            val,
+            clone: T::clone,
+        }));
+        Ok(())
+    }
+
+    /// Set a closure that implements [Fn]
+    pub fn set<F>(&self, closure: F) -> Result<(), Error>
+    where
+        F: Fn() -> T + Send + Sync + 'static,
+    {
+        self.state
+            .swap(Arc::new(ValueSource::Dynamic(Box::new(closure))));
+        Ok(())
+    }
+
+    /// Set a closure that implements [FnMut]
+    pub fn set_mut<F>(&self, closure: F) -> Result<(), Error>
+    where
+        F: FnMut() -> T + Send + Sync + 'static,
+    {
+        self.state
+            .swap(Arc::new(ValueSource::DynamicMut(Mutex::new(Box::new(
+                closure,
+            )))));
+        Ok(())
+    }
+
+    /// Close the channel
+    pub fn close(&self) -> Result<(), Error> {
+        self.state.swap(Arc::new(ValueSource::Cleared));
+        Ok(())
+    }
+
+    /// Handles requests - blocking
+    pub fn run(self) -> Result<(), Error> {
+        loop {
+            match self.request_rx.recv() {
+                Ok(Request::GetValue) => {
+                    let response = self.handle_get_value()?;
+                    if self.response_tx.send(response).is_err() {
+                        // Consumer disconnected
+                        break;
+                    }
+                }
+                Ok(Request::Close) => {
+                    // Close channel
+                    self.close()?;
+                    break;
+                }
+                Err(_) => {
+                    // Consumer disconnected
+                    break;
+                }
+            }
+        }
+        Ok(())
+    }
+
+    fn handle_get_value(&self) -> Result<Response<T>, Error> {
+        let state = self.state.load();
+
+        match &**state {
+            ValueSource::Static { val, clone } => {
+                let value = self.execute_closure_safely(&mut || clone(val));
+                match value {
+                    Ok(v) => Ok(Response::Value(v)),
+                    Err(_) => Ok(Response::NoSource), // Closure execution failed
+                }
+            }
+            ValueSource::Dynamic(closure) => {
+                let value = self.execute_closure_safely(&mut || closure());
+                match value {
+                    Ok(v) => Ok(Response::Value(v)),
+                    Err(_) => Ok(Response::NoSource), // Closure execution failed
+                }
+            }
+            ValueSource::DynamicMut(closure) => {
+                let mut closure = closure.lock().unwrap();
+                let value = self.execute_closure_safely(&mut *closure);
+                match value {
+                    Ok(v) => Ok(Response::Value(v)),
+                    Err(_) => Ok(Response::NoSource), // Closure execution failed
+                }
+            }
+            ValueSource::None => Ok(Response::NoSource), // No source was ever set
+            ValueSource::Cleared => Ok(Response::Closed), // Channel was closed (source was set then cleared)
+        }
+    }
+
+    fn execute_closure_safely(
+        &self,
+        closure: &mut dyn FnMut() -> T,
+    ) -> Result<T, Box<dyn std::any::Any + Send>> {
+        std::panic::catch_unwind(std::panic::AssertUnwindSafe(closure))
+    }
+}
+
+impl<T, ST, SR> Sucker<T, ST, SR>
+where
+    ST: ChannelSender<Request>,
+    SR: ChannelReceiver<Response<T>>,
+{
+    /// Get the current value from the producer
+    pub fn get(&self) -> Result<T, Error> {
+        // Check if locally marked as closed
+        if self.closed.load(Ordering::Acquire) {
+            return Err(Error::ChannelClosed);
+        }
+
+        self.request_tx
+            .send(Request::GetValue)
+            .map_err(|_| Error::ProducerDisconnected)?;
+
+        match self.response_rx.recv() {
+            Ok(Response::Value(value)) => Ok(value),
+            Ok(Response::NoSource) => Err(Error::NoSource),
+            Ok(Response::Closed) => Err(Error::ChannelClosed),
+            Err(_) => Err(Error::ProducerDisconnected),
+        }
+    }
+
+    /// Check if the channel is closed
+    pub fn is_closed(&self) -> bool {
+        // Send a test request
+        self.request_tx.send(Request::GetValue).is_err()
+    }
+
+    /// Close the channel from the consumer side
+    pub fn close(&self) -> Result<(), Error> {
+        // Mark locally as closed
+        self.closed.store(true, Ordering::Release);
+
+        // Send close request
+        self.request_tx
+            .send(Request::Close)
+            .map_err(|_| Error::ProducerDisconnected)
+    }
+}

src/sync/crossbeam.rs

@@ -7,9 +7,17 @@ use arc_swap::ArcSwap;
 use crossbeam_channel;
 
 type CrossbeamSucker<T> =
-    crate::Sucker<T, CrossbeamSender<types::Request>, CrossbeamReceiver<types::Response<T>>>;
+    crate::sync::channel::Sucker<
+        T,
+        CrossbeamSender<types::Request>,
+        CrossbeamReceiver<types::Response<T>>,
+    >;
 type CrossbeamSourcer<T> =
-    crate::Sourcer<T, CrossbeamReceiver<types::Request>, CrossbeamSender<types::Response<T>>>;
+    crate::sync::channel::Sourcer<
+        T,
+        CrossbeamReceiver<types::Request>,
+        CrossbeamSender<types::Response<T>>,
+    >;
 
 /// Internal sender type for crossbeam backend
 pub struct CrossbeamSender<T>(crossbeam_channel::Sender<T>);
@@ -67,8 +75,8 @@ impl<T> CrossbeamSuck<T> {
 
         let state = ArcSwap::new(Arc::new(crate::types::ValueSource::None));
 
-        let sucker = crate::Sucker::new(request_tx, response_rx);
-        let sourcer = crate::Sourcer::new(request_rx, response_tx, state);
+        let sucker = crate::sync::channel::Sucker::new(request_tx, response_rx);
+        let sourcer = crate::sync::channel::Sourcer::new(request_rx, response_tx, state);
 
         (sucker, sourcer)
     }

src/sync/flume.rs

@@ -7,9 +7,9 @@ use arc_swap::ArcSwap;
 use flume;
 
 type FlumeSucker<T> =
-    crate::Sucker<T, FlumeSender<types::Request>, FlumeReceiver<types::Response<T>>>;
+    crate::sync::channel::Sucker<T, FlumeSender<types::Request>, FlumeReceiver<types::Response<T>>>;
 type FlumeSourcer<T> =
-    crate::Sourcer<T, FlumeReceiver<types::Request>, FlumeSender<types::Response<T>>>;
+    crate::sync::channel::Sourcer<T, FlumeReceiver<types::Request>, FlumeSender<types::Response<T>>>;
 
 /// Internal sender type for flume backend  
 pub struct FlumeSender<T>(flume::Sender<T>);
@@ -68,8 +68,8 @@ impl<T> FlumeSuck<T> {
         let state = Arc::new(crate::types::ValueSource::None);
         let state = ArcSwap::new(state);
 
-        let sucker = crate::Sucker::new(request_tx, response_rx);
-        let sourcer = crate::Sourcer::new(request_rx, response_tx, state);
+        let sucker = crate::sync::channel::Sucker::new(request_tx, response_rx);
+        let sourcer = crate::sync::channel::Sourcer::new(request_rx, response_tx, state);
 
         (sucker, sourcer)
     }

src/sync/mod.rs

@@ -1,4 +1,5 @@
 pub mod traits;
+pub mod channel;
 
 #[cfg(feature = "sync-crossbeam")]
 pub mod crossbeam;

src/sync/std.rs

@@ -6,8 +6,10 @@ use std::sync::Arc;
 #[cfg(feature = "sync-std")]
 use std::sync::mpsc;
 
-type StdSucker<T> = crate::Sucker<T, StdSender<types::Request>, StdReceiver<types::Response<T>>>;
-type StdSourcer<T> = crate::Sourcer<T, StdReceiver<types::Request>, StdSender<types::Response<T>>>;
+type StdSucker<T> =
+    crate::sync::channel::Sucker<T, StdSender<types::Request>, StdReceiver<types::Response<T>>>;
+type StdSourcer<T> =
+    crate::sync::channel::Sourcer<T, StdReceiver<types::Request>, StdSender<types::Response<T>>>;
 
 /// Internal sender type for std backend
 pub struct StdSender<T>(mpsc::Sender<T>);
@@ -66,8 +68,8 @@ impl<T> StdSuck<T> {
         let state = Arc::new(crate::types::ValueSource::None);
         let state = ArcSwap::new(state);
 
-        let sucker = crate::Sucker::new(request_tx, response_rx);
-        let sourcer = crate::Sourcer::new(request_rx, response_tx, state);
+        let sucker = crate::sync::channel::Sucker::new(request_tx, response_rx);
+        let sourcer = crate::sync::channel::Sourcer::new(request_rx, response_tx, state);
 
         (sucker, sourcer)
     }
@@ -236,7 +238,7 @@ mod tests {
 
         let state = Arc::new(crate::types::ValueSource::None);
         let state = ArcSwap::new(state);
-        let sourcer = crate::Sourcer::new(request_rx, response_tx, state);
+        let sourcer = crate::sync::channel::Sourcer::new(request_rx, response_tx, state);
         sourcer.set_static(42).unwrap();
 
         let producer_handle = thread::spawn(move || sourcer.run().unwrap());
@@ -254,7 +256,7 @@ mod tests {
 
         let state = Arc::new(crate::types::ValueSource::None);
         let state = ArcSwap::new(state);
-        let sourcer = crate::Sourcer::new(request_rx, response_tx, state);
+        let sourcer = crate::sync::channel::Sourcer::new(request_rx, response_tx, state);
 
         sourcer.run().unwrap();
     }