Sink: pass ownership of the packet on write()

Prevent a copy if the implementation needs to keep the data around.

Author: gdesmott

CHANGELOG.md

@@ -13,6 +13,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [playback] `alsa`: Improve `--device ?` functionality for the alsa backend.
 - [contrib] Hardened security of the systemd service units
 - [main] Verbose logging mode (`-v`, `--verbose`) now logs all parsed environment variables and command line arguments (credentials are redacted).
+- [playback] `Sink`: `write()` now receives ownership of the packet (breaking).
 
 ### Added
 - [cache] Add `disable-credential-cache` flag (breaking).

playback/src/audio_backend/jackaudio.rs

@@ -66,7 +66,7 @@ impl Open for JackSink {
 }
 
 impl Sink for JackSink {
-    fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()> {
+    fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
         let samples = packet
             .samples()
             .map_err(|e| SinkError::OnWrite(e.to_string()))?;

playback/src/audio_backend/mod.rs

@@ -28,7 +28,7 @@ pub trait Sink {
     fn stop(&mut self) -> SinkResult<()> {
         Ok(())
     }
-    fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()>;
+    fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()>;
 }
 
 pub type SinkBuilder = fn(Option<String>, AudioFormat) -> Box<dyn Sink>;
@@ -44,34 +44,34 @@ fn mk_sink<S: Sink + Open + 'static>(device: Option<String>, format: AudioFormat
 // reuse code for various backends
 macro_rules! sink_as_bytes {
     () => {
-        fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()> {
+        fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
             use crate::convert::i24;
             use zerocopy::AsBytes;
             match packet {
                 AudioPacket::Samples(samples) => match self.format {
                     AudioFormat::F64 => self.write_bytes(samples.as_bytes()),
                     AudioFormat::F32 => {
-                        let samples_f32: &[f32] = &converter.f64_to_f32(samples);
+                        let samples_f32: &[f32] = &converter.f64_to_f32(&samples);
                         self.write_bytes(samples_f32.as_bytes())
                     }
                     AudioFormat::S32 => {
-                        let samples_s32: &[i32] = &converter.f64_to_s32(samples);
+                        let samples_s32: &[i32] = &converter.f64_to_s32(&samples);
                         self.write_bytes(samples_s32.as_bytes())
                     }
                     AudioFormat::S24 => {
-                        let samples_s24: &[i32] = &converter.f64_to_s24(samples);
+                        let samples_s24: &[i32] = &converter.f64_to_s24(&samples);
                         self.write_bytes(samples_s24.as_bytes())
                     }
                     AudioFormat::S24_3 => {
-                        let samples_s24_3: &[i24] = &converter.f64_to_s24_3(samples);
+                        let samples_s24_3: &[i24] = &converter.f64_to_s24_3(&samples);
                         self.write_bytes(samples_s24_3.as_bytes())
                     }
                     AudioFormat::S16 => {
-                        let samples_s16: &[i16] = &converter.f64_to_s16(samples);
+                        let samples_s16: &[i16] = &converter.f64_to_s16(&samples);
                         self.write_bytes(samples_s16.as_bytes())
                     }
                 },
-                AudioPacket::OggData(samples) => self.write_bytes(samples),
+                AudioPacket::OggData(samples) => self.write_bytes(&samples),
             }
         }
     };

playback/src/audio_backend/portaudio.rs

@@ -140,7 +140,7 @@ impl<'a> Sink for PortAudioSink<'a> {
         Ok(())
     }
 
-    fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()> {
+    fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
         macro_rules! write_sink {
             (ref mut $stream: expr, $samples: expr) => {
                 $stream.as_mut().unwrap().write($samples)
@@ -153,15 +153,15 @@ impl<'a> Sink for PortAudioSink<'a> {
 
         let result = match self {
             Self::F32(stream, _parameters) => {
-                let samples_f32: &[f32] = &converter.f64_to_f32(samples);
+                let samples_f32: &[f32] = &converter.f64_to_f32(&samples);
                 write_sink!(ref mut stream, samples_f32)
             }
             Self::S32(stream, _parameters) => {
-                let samples_s32: &[i32] = &converter.f64_to_s32(samples);
+                let samples_s32: &[i32] = &converter.f64_to_s32(&samples);
                 write_sink!(ref mut stream, samples_s32)
             }
             Self::S16(stream, _parameters) => {
-                let samples_s16: &[i16] = &converter.f64_to_s16(samples);
+                let samples_s16: &[i16] = &converter.f64_to_s16(&samples);
                 write_sink!(ref mut stream, samples_s16)
             }
         };

playback/src/audio_backend/rodio.rs

@@ -189,7 +189,7 @@ pub fn open(host: cpal::Host, device: Option<String>, format: AudioFormat) -> Ro
 }
 
 impl Sink for RodioSink {
-    fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()> {
+    fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
         let samples = packet
             .samples()
             .map_err(|e| RodioError::Samples(e.to_string()))?;

playback/src/audio_backend/sdl.rs

@@ -82,7 +82,7 @@ impl Sink for SdlSink {
         Ok(())
     }
 
-    fn write(&mut self, packet: &AudioPacket, converter: &mut Converter) -> SinkResult<()> {
+    fn write(&mut self, packet: AudioPacket, converter: &mut Converter) -> SinkResult<()> {
         macro_rules! drain_sink {
             ($queue: expr, $size: expr) => {{
                 // sleep and wait for sdl thread to drain the queue a bit

playback/src/player.rs

@@ -1384,7 +1384,7 @@ impl PlayerInternal {
                         }
                     }
 
-                    if let Err(e) = self.sink.write(&packet, &mut self.converter) {
+                    if let Err(e) = self.sink.write(packet, &mut self.converter) {
                         error!("{}", e);
                         exit(1);
                     }