Fixed-size tx/rx queues, improved error messages, 'any frame' callback handler, zero-length data payloads.

examples/python_send_receive_callbacks/main.py

@@ -19,9 +19,16 @@ def on_frame_d(frame : jcan.Frame):
         print(f"FRAME 1AD {frame.data}")
         # print(frame.data[0])
 
+    def on_anyother_frame(frame: jcan.Frame):
+        print(f"FRAME {frame.id}: {frame.data}")
+
     bus.add_callback(0x1A5, on_frame_five)
     bus.add_callback(0x1AD, on_frame_d)
 
+    # The add_callback for ID zero will be called when any other frame is received,
+    # as long as that frame does not have a callback associated with it.
+    bus.add_callback(0x0, on_anyother_frame)
+
     bus.open("vcan0")
 
     while True:

jcan-python/src/lib.rs

@@ -39,7 +39,7 @@ impl PyJBus {
     fn new() -> PyResult<Self> {
         // Unbox the result of new_jbus, and return it
         let bus = new_jbus().map_err(|e| {
-            PyOSError::new_err(format!("Error creating Bus: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
 
         // bus is a Box<JBus>, so we need to dereference it
@@ -50,17 +50,19 @@ impl PyJBus {
     }
 
     // Implement the open method for the PyJBus
-    fn open(&mut self, interface: String) -> PyResult<()> {
-        self.bus.open(interface).map_err(|e| {
-            PyOSError::new_err(format!("Error opening bus: {}", e))
+    // Add pyo3 default arguments of 256 for tx_queue_len and rx_queue_len
+    #[args(tx_queue_len = 256, rx_queue_len = 256)]
+    fn open(&mut self, interface: String, tx_queue_len: u16, rx_queue_len: u16) -> PyResult<()> {
+        self.bus.open(interface, tx_queue_len, rx_queue_len).map_err(|e| {
+            PyOSError::new_err(format!("{}", e))
         })?;
         Ok(())
     }
 
     // Implement the receive method for the PyJBus
     fn receive(&mut self) -> PyResult<PyJFrame> {
         let frame = self.bus.receive().map_err(|e| {
-            PyOSError::new_err(format!("Error receiving frame: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
         Ok(PyJFrame {
             frame,
@@ -70,30 +72,30 @@ impl PyJBus {
     // Implement the send method for the PyJBus
     fn send(&mut self, frame: PyJFrame) -> PyResult<()> {
         self.bus.send(frame.frame).map_err(|e| {
-            PyOSError::new_err(format!("Error sending frame: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
         Ok(())
     }
 
     // Implement set_id_filter for the PyJBus, which takes a list of IDs
     fn set_id_filter(&mut self, allowed_ids: Vec<u32>) -> PyResult<()> {
         self.bus.set_id_filter(allowed_ids).map_err(|e| {
-            PyOSError::new_err(format!("Error setting filter: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
         Ok(())
     }
 
     fn set_id_filter_mask(&mut self, allowed: u32, allowed_mask: u32) -> PyResult<()> {
         self.bus.set_id_filter_mask(allowed, allowed_mask).map_err(|e| {
-            PyOSError::new_err(format!("Error setting filter mask: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
         Ok(())
     }
 
     // Receive many will return a list of buffered frames from the receive thread
     fn receive_from_thread_buffer(&mut self) -> PyResult<Vec<PyJFrame>> {
         let frames = self.bus.receive_from_thread_buffer().map_err(|e| {
-            PyOSError::new_err(format!("Error receiving frames: {}", e))
+            PyOSError::new_err(format!("{}", e))
         })?;
 
         Ok(frames.into_iter().map(|f| PyJFrame {
@@ -133,10 +135,16 @@ impl PyJBus {
         let _gil = Python::with_gil(|py| {
             for frame in frames {
                 // Lookup the callback function for the frame, given its ID
-                // If no callback is found, ignore the frame
+                // If no callback is found, check if we have an 'any' callback (ID of 0) assigned,
+                // otherwise ignore the frame.
                 let callback = match self.callbacks.get(&frame.frame.id) {
                     Some(c) => c,
-                    None => continue,
+                    None => {
+                        match self.callbacks.get(&0) {
+                            Some(c) => c,
+                            None => continue,
+                        }
+                    },
                 };
 
                 // Call the callback function with the frame as an argument

jcan/Cargo.toml

@@ -26,6 +26,8 @@ nix = "0.26"
 serial_test = "0.9"
 socketcan = { git = "https://github.com/socketcan-rs/socketcan-rs", version = "2.0.0-pre.0" }
 cxx = "1.0"
+env_logger = "0.10.0"
+log = "0.4.17"
 
 [build-dependencies]
 cxx-build = "1.0"

jcan/include/callback.h

@@ -28,7 +28,7 @@ class Bus{
 public:
 
   Bus();
-  void open(const char *name);
+  void open(const char *name, uint16_t tx_queue_len, uint16_t rx_queue_len);
 
   void set_id_filter(std::vector<uint32_t> allowed_ids);
   void set_id_filter_mask(uint32_t allowed, uint32_t mask);

jcan/src/callback.cc

@@ -12,8 +12,8 @@ namespace org::jcan
       return std::unique_ptr<Bus>(new Bus());
    }
 
-   void Bus::open(const char *name) {
-      this->jBus->open(name);
+   void Bus::open(const char *name, uint16_t tx_queue_len, uint16_t rx_queue_len) {
+      this->jBus->open(name, tx_queue_len, rx_queue_len);
    }
 
    void Bus::set_id_filter(std::vector<uint32_t> allowed_ids) {
@@ -55,11 +55,21 @@ namespace org::jcan
     // For each frame, call the callback function associated with the frame's ID
     for (auto frame : frames) {
       auto it = this->callbacks_.find(frame.id);
-      // If the ID is not in the map, do nothing
+
+      // If the ID is not in the map, check if we have an 'any' callback of ID 0 assigned
       if (it != this->callbacks_.end())
       {
         // Call the callback function
         it->second(frame);
+      }else{
+         // Check if '0' callback exists
+         auto it_any = this->callbacks_.find(0);
+
+         if (it_any != this->callbacks_.end())
+         {
+            // Call the '0' callback
+            it_any->second(frame);
+         }
       }
     }
   }