Introduce recv_blocking() method on PayloadReceiver

Allows callers to wait for a frame without using futures. Also bump async-std dependency to 1.12 (unfortunately still doesn't ensure recent-enough `async-channel` - but I'll fix that in another PR). Also update the stream example and READMEs with the new method, making it print any receive errors (but not panic on them) and doing exactly 10 tries (instead of waiting for 10 success payloads).
cameleon-rs · Mar 14, 2023 · 7162e21 · 7162e21
1 parent 235672b
commit 7162e21
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Showing 6 changed files with 63 additions and 65 deletions.
diff --git a/README.md b/README.md
@@ -62,30 +62,28 @@ camera.load_context().unwrap();
 // Start streaming. Channel capacity is set to 3.
 let payload_rx = camera.start_streaming(3).unwrap();
 
-let mut payload_count = 0;
-while payload_count < 10 {
-    match payload_rx.try_recv() {
-        Ok(payload) => {
-            println!(
-                "payload received! block_id: {:?}, timestamp: {:?}",
-                payload.id(),
-                payload.timestamp()
-            );
-            if let Some(image_info) = payload.image_info() {
-                println!("{:?}\n", image_info);
-                let image = payload.image();
-                // do something with the image.
-                // ...
-            }
-            payload_count += 1;
-
-            // Send back payload to streaming loop to reuse the buffer. This is optional.
-            payload_rx.send_back(payload);
-        }
-        Err(_err) => {
+for _ in 0..10 {
+    let payload = match payload_rx.recv_blocking() {
+        Ok(payload) => payload,
+        Err(e) => {
+            println!("payload receive error: {e}");
             continue;
         }
+    };
+    println!(
+        "payload received! block_id: {:?}, timestamp: {:?}",
+        payload.id(),
+        payload.timestamp()
+    );
+    if let Some(image_info) = payload.image_info() {
+        println!("{:?}\n", image_info);
+        let image = payload.image();
+        // do something with the image.
+        // ...
     }
+
+    // Send back payload to streaming loop to reuse the buffer. This is optional.
+    payload_rx.send_back(payload);
 }
 
 // Closes the camera.

diff --git a/cameleon/Cargo.toml b/cameleon/Cargo.toml
@@ -20,7 +20,7 @@ thiserror = "1.0.24"
 semver = "1.0.0"
 zip = "0.6.0"
 sha-1 = "0.10.0"
-async-std = { version = "1.9.0", features = ["unstable"] }
+async-std = { version = "1.12.0", features = ["unstable"] }
 tracing = "0.1.26"
 auto_impl = "1.0.1"
 cameleon-device = { path = "../device", version = "0.1.8" }

diff --git a/cameleon/README.md b/cameleon/README.md
@@ -62,30 +62,28 @@ camera.load_context().unwrap();
 // Start streaming. Channel capacity is set to 3.
 let payload_rx = camera.start_streaming(3).unwrap();
 
-let mut payload_count = 0;
-while payload_count < 10 {
-    match payload_rx.try_recv() {
-        Ok(payload) => {
-            println!(
-                "payload received! block_id: {:?}, timestamp: {:?}",
-                payload.id(),
-                payload.timestamp()
-            );
-            if let Some(image_info) = payload.image_info() {
-                println!("{:?}\n", image_info);
-                let image = payload.image();
-                // do something with the image.
-                // ...
-            }
-            payload_count += 1;
-
-            // Send back payload to streaming loop to reuse the buffer. This is optional.
-            payload_rx.send_back(payload);
-        }
-        Err(_err) => {
+for _ in 0..10 {
+    let payload = match payload_rx.recv_blocking() {
+        Ok(payload) => payload,
+        Err(e) => {
+            println!("payload receive error: {e}");
             continue;
         }
+    };
+    println!(
+        "payload received! block_id: {:?}, timestamp: {:?}",
+        payload.id(),
+        payload.timestamp()
+    );
+    if let Some(image_info) = payload.image_info() {
+        println!("{:?}\n", image_info);
+        let image = payload.image();
+        // do something with the image.
+        // ...
     }
+
+    // Send back payload to streaming loop to reuse the buffer. This is optional.
+    payload_rx.send_back(payload);
 }
 
 // Closes the camera.
@@ -188,4 +186,3 @@ To start developing, please refer to [CONTRIBUTING.md][contributing].
 This project is licenced under [MPL 2.0][license].
 
 [license]: https://github.com/cameleon-rs/cameleon/blob/main/LICENSE
-
diff --git a/cameleon/examples/stream.rs b/cameleon/examples/stream.rs
@@ -25,27 +25,25 @@ fn main() {
     // Start streaming. Channel capacity is set to 3.
     let payload_rx = camera.start_streaming(3).unwrap();
 
-    let mut payload_count = 0_usize;
-    while payload_count < 10 {
-        match payload_rx.try_recv() {
-            Ok(payload) => {
-                println!(
-                    "payload received! block_id: {:?}, timestamp: {:?}",
-                    payload.id(),
-                    payload.timestamp()
-                );
-                if let Some(image_info) = payload.image_info() {
-                    println!("{:?}\n", image_info);
-                }
-                payload_count += 1;
-
-                // Send back payload to streaming loop to reuse the buffer.
-                payload_rx.send_back(payload);
-            }
-            Err(_err) => {
+    for _ in 0..10 {
+        let payload = match payload_rx.recv_blocking() {
+            Ok(payload) => payload,
+            Err(e) => {
+                println!("payload receive error: {e}");
                 continue;
             }
+        };
+        println!(
+            "payload received! block_id: {:?}, timestamp: {:?}",
+            payload.id(),
+            payload.timestamp()
+        );
+        if let Some(image_info) = payload.image_info() {
+            println!("{:?}\n", image_info);
         }
+
+        // Send back payload to streaming loop to reuse the buffer.
+        payload_rx.send_back(payload);
     }
 
     camera.close().ok();

diff --git a/cameleon/src/payload.rs b/cameleon/src/payload.rs
@@ -122,6 +122,12 @@ impl PayloadReceiver {
         self.rx.try_recv()?
     }
 
+    /// Receives [`Payload`] sent from the device.
+    /// If the channel is empty, this method blocks until the device produces the payload.
+    pub fn recv_blocking(&self) -> StreamResult<Payload> {
+        self.rx.recv_blocking()?
+    }
+
     /// Sends back [`Payload`] to the device to reuse already allocated `payload`.
     ///
     /// Sending back `payload` may improve performance of streaming, but not required to call this

diff --git a/device/Cargo.toml b/device/Cargo.toml
@@ -10,14 +10,14 @@ repository = "https://github.com/cameleon-rs/cameleon"
 description = """
 cameleon-device provides device specific protocol decoders and basic I/O operations for GenICam compatible devices.
 """
-categories = ["computer-vision"] 
+categories = ["computer-vision"]
 keywords = ["genicam", "camera", "usb3", "gige", "uvc"]
 
 [dependencies]
 thiserror = "1.0.24"
 log = "0.4.14"
 semver = "1.0.0"
-async-std = { version = "1.9.0", features = ["unstable"] }
+async-std = { version = "1.12.0", features = ["unstable"] }
 const_format = "0.2.14"
 futures = "0.3.14"
 lazy_static = "1.4.0"
@@ -29,7 +29,6 @@ rusb = { version = "0.9.0", optional = true }
 libusb1-sys = { version = "0.6.0", optional = true }
 libc = { version = "0.2", optional = true }
 
-
 [dev-dependencies]
 trybuild = "1.0.42"