Use let-else instead of match for weak reference upgrades

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1333>

examples/src/bin/custom_events.rs

@@ -115,9 +115,8 @@ fn example_main() {
         glib::timeout_add_seconds(2 + i as u32, move || {
             // Here we temporarily retrieve a strong reference on the pipeline from the weak one
             // we moved into this callback.
-            let pipeline = match pipeline_weak.upgrade() {
+            let Some(pipeline) = pipeline_weak.upgrade() else {
-                Some(pipeline) => pipeline,
+                return glib::ControlFlow::Break;
-                None => return glib::ControlFlow::Break,
             };
             println!("Sending custom event to the pipeline with send_eos={send_eos}");
             let ev = ExampleCustomEvent::new(*send_eos);

examples/src/bin/decodebin.rs

@@ -90,9 +90,8 @@ fn example_main() -> Result<(), Error> {
     decodebin.connect_pad_added(move |dbin, src_pad| {
         // Here we temporarily retrieve a strong reference on the pipeline from the weak one
         // we moved into this callback.
-        let pipeline = match pipeline_weak.upgrade() {
+        let Some(pipeline) = pipeline_weak.upgrade() else {
-            Some(pipeline) => pipeline,
+            return;
-            None => return,
         };
 
         // Try to detect whether the raw stream decodebin provided us with

examples/src/bin/encodebin.rs

@@ -120,9 +120,8 @@ fn example_main() -> Result<(), Error> {
     src.connect_pad_added(move |dbin, dbin_src_pad| {
         // Here we temporarily retrieve a strong reference on the pipeline from the weak one
         // we moved into this callback.
-        let pipeline = match pipeline_weak.upgrade() {
+        let Some(pipeline) = pipeline_weak.upgrade() else {
-            Some(pipeline) => pipeline,
+            return;
-            None => return,
         };
 
         let (is_audio, is_video) = {

examples/src/bin/events.rs

@@ -55,9 +55,8 @@ fn example_main() {
     glib::timeout_add_seconds(5, move || {
         // Here we temporarily retrieve a strong reference on the pipeline from the weak one
         // we moved into this callback.
-        let pipeline = match pipeline_weak.upgrade() {
+        let Some(pipeline) = pipeline_weak.upgrade() else {
-            Some(pipeline) => pipeline,
+            return glib::ControlFlow::Break;
-            None => return glib::ControlFlow::Break,
         };
 
         println!("sending eos");

examples/src/bin/queries.rs

@@ -50,9 +50,8 @@ fn example_main() {
     let timeout_id = glib::timeout_add_seconds(1, move || {
         // Here we temporarily retrieve a strong reference on the pipeline from the weak one
         // we moved into this callback.
-        let pipeline = match pipeline_weak.upgrade() {
+        let Some(pipeline) = pipeline_weak.upgrade() else {
-            Some(pipeline) => pipeline,
+            return glib::ControlFlow::Break;
-            None => return glib::ControlFlow::Continue,
         };
 
         //let pos = pipeline.query_position(gst::Format::Time).unwrap_or(-1);

examples/src/bin/rtpfecclient.rs

@@ -203,9 +203,8 @@ fn example_main() -> Result<(), Error> {
 
     let depay_weak = depay.downgrade();
     rtpbin.connect_pad_added(move |rtpbin, src_pad| {
-        let depay = match depay_weak.upgrade() {
+        let Some(depay) = depay_weak.upgrade() else {
-            Some(depay) => depay,
+            return;
-            None => return,
         };
 
         match connect_rtpbin_srcpad(src_pad, &depay) {

examples/src/bin/toc.rs

@@ -52,9 +52,8 @@ fn example_main() {
     decodebin.connect_pad_added(move |_, src_pad| {
         // Here we temporarily retrieve a strong reference on the pipeline from the weak one
         // we moved into this callback.
-        let pipeline = match pipeline_weak.upgrade() {
+        let Some(pipeline) = pipeline_weak.upgrade() else {
-            Some(pipeline) => pipeline,
+            return;
-            None => return,
         };
 
         // In this example, we are only interested about parsing the ToC, so

gstreamer-app/src/app_sink.rs

@@ -1254,9 +1254,8 @@ impl Stream for AppSinkStream {
     fn poll_next(self: Pin<&mut Self>, context: &mut Context) -> Poll<Option<Self::Item>> {
         let mut waker = self.waker_reference.lock().unwrap();
 
-        let app_sink = match self.app_sink.upgrade() {
+        let Some(app_sink) = self.app_sink.upgrade() else {
-            Some(app_sink) => app_sink,
+            return Poll::Ready(None);
-            None => return Poll::Ready(None),
         };
 
         app_sink

gstreamer-app/src/app_src.rs

@@ -588,9 +588,8 @@ impl Sink<gst::Sample> for AppSrcSink {
     fn poll_ready(self: Pin<&mut Self>, context: &mut Context) -> Poll<Result<(), Self::Error>> {
         let mut waker = self.waker_reference.lock().unwrap();
 
-        let app_src = match self.app_src.upgrade() {
+        let Some(app_src) = self.app_src.upgrade() else {
-            Some(app_src) => app_src,
+            return Poll::Ready(Err(gst::FlowError::Eos));
-            None => return Poll::Ready(Err(gst::FlowError::Eos)),
         };
 
         let current_level_bytes = app_src.current_level_bytes();
@@ -606,9 +605,8 @@ impl Sink<gst::Sample> for AppSrcSink {
     }
 
     fn start_send(self: Pin<&mut Self>, sample: gst::Sample) -> Result<(), Self::Error> {
-        let app_src = match self.app_src.upgrade() {
+        let Some(app_src) = self.app_src.upgrade() else {
-            Some(app_src) => app_src,
+            return Err(gst::FlowError::Eos);
-            None => return Err(gst::FlowError::Eos),
         };
 
         app_src.push_sample(&sample)?;
@@ -621,9 +619,8 @@ impl Sink<gst::Sample> for AppSrcSink {
     }
 
     fn poll_close(self: Pin<&mut Self>, _: &mut Context) -> Poll<Result<(), Self::Error>> {
-        let app_src = match self.app_src.upgrade() {
+        let Some(app_src) = self.app_src.upgrade() else {
-            Some(app_src) => app_src,
+            return Poll::Ready(Ok(()));
-            None => return Poll::Ready(Ok(())),
         };
 
         app_src.end_of_stream()?;

tutorials/src/bin/basic-tutorial-12.rs

@@ -24,9 +24,8 @@ fn tutorial_main() -> Result<(), Error> {
     let bus = pipeline.bus().expect("Pipeline has no bus");
     let _bus_watch = bus
         .add_watch(move |_, msg| {
-            let pipeline = match pipeline_weak.upgrade() {
+            let Some(pipeline) = pipeline_weak.upgrade() else {
-                Some(pipeline) => pipeline,
+                return glib::ControlFlow::Continue;
-                None => return glib::ControlFlow::Continue,
             };
             let main_loop = &main_loop_clone;
             match msg.view() {

tutorials/src/bin/basic-tutorial-8.rs

@@ -165,9 +165,8 @@ fn main() {
     appsrc.set_callbacks(
         gst_app::AppSrcCallbacks::builder()
             .need_data(move |_, _size| {
-                let data = match data_weak.upgrade() {
+                let Some(data) = data_weak.upgrade() else {
-                    Some(data) => data,
+                    return;
-                    None => return,
                 };
                 let mut d = data.lock().unwrap();
 
@@ -176,9 +175,8 @@ fn main() {
 
                     let data_weak = Arc::downgrade(&data);
                     d.source_id = Some(glib::source::idle_add(move || {
-                        let data = match data_weak.upgrade() {
+                        let Some(data) = data_weak.upgrade() else {
-                            Some(data) => data,
+                            return glib::ControlFlow::Break;
-                            None => return glib::ControlFlow::Break,
                         };
 
                         let (appsrc, buffer) = {
@@ -224,9 +222,8 @@ fn main() {
                 }
             })
             .enough_data(move |_| {
-                let data = match data_weak2.upgrade() {
+                let Some(data) = data_weak2.upgrade() else {
-                    Some(data) => data,
+                    return;
-                    None => return,
                 };
 
                 let mut data = data.lock().unwrap();
@@ -242,9 +239,8 @@ fn main() {
     appsink.set_callbacks(
         gst_app::AppSinkCallbacks::builder()
             .new_sample(move |_| {
-                let data = match data_weak.upgrade() {
+                let Some(data) = data_weak.upgrade() else {
-                    Some(data) => data,
+                    return Ok(gst::FlowSuccess::Ok);
-                    None => return Ok(gst::FlowSuccess::Ok),
                 };
 
                 let appsink = {

tutorials/src/bin/playback-tutorial-3.rs

@@ -82,9 +82,8 @@ fn tutorial_main() -> Result<(), Error> {
 
                         let data_weak = Arc::downgrade(data);
                         d.source_id = Some(glib::source::idle_add(move || {
-                            let data = match data_weak.upgrade() {
+                            let Some(data) = data_weak.upgrade() else {
-                                Some(data) => data,
+                                return glib::ControlFlow::Break;
-                                None => return glib::ControlFlow::Break,
                             };
 
                             let (appsrc, buffer) = {

tutorials/src/bin/playback-tutorial-4.rs

@@ -56,9 +56,8 @@ fn tutorial_main() -> Result<(), Error> {
             use gst::MessageView;
 
             let buffering_level = &buffering_level_clone;
-            let pipeline = match pipeline_weak.upgrade() {
+            let Some(pipeline) = pipeline_weak.upgrade() else {
-                Some(pipeline) => pipeline,
+                return glib::ControlFlow::Break;
-                None => return glib::ControlFlow::Break,
             };
             let main_loop = &main_loop_clone;
             match msg.view() {
@@ -116,9 +115,8 @@ fn tutorial_main() -> Result<(), Error> {
     let timeout_id = glib::timeout_add_seconds(1, move || {
         use gst::{format::Percent, GenericFormattedValue as GFV};
 
-        let pipeline = match pipeline_weak_.upgrade() {
+        let Some(pipeline) = pipeline_weak_.upgrade() else {
-            Some(pipeline) => pipeline,
+            return glib::ControlFlow::Break;
-            None => return glib::ControlFlow::Break,
         };
         let mut graph = vec![b' '; GRAPH_LENGTH];
         let mut buffering = gst::query::Buffering::new(gst::Format::Percent);