Introduce Arc-based sharing of audio data

src/agents/audio_agent.rs

@@ -1,6 +1,6 @@
 use js_sys::Uint8Array;
 use std::collections::HashSet;
-use std::rc::Rc;
+use std::sync::Arc;
 use wasm_bindgen::JsValue;
 use wasm_bindgen_futures::JsFuture;
 use web_sys::console;
@@ -12,7 +12,7 @@ use yewtil::future::LinkFuture;
 
 const FILE_LOAD_CHUNK_SIZE: usize = 4096;
 
-pub type AudioData = Rc<web_sys::AudioBuffer>;
+pub type AudioData = Arc<web_sys::AudioBuffer>;
 
 #[derive(Debug)]
 pub struct AudioAgent {
@@ -79,7 +79,7 @@ impl Agent for AudioAgent {
             }
             Msg::AudioDecoded(samples) => {
                 let audio_buffer = web_sys::AudioBuffer::from(samples);
-                let audio_data = Rc::new(audio_buffer);
+                let audio_data = Arc::new(audio_buffer);
 
                 for subscriber in self.subscribers.iter() {
                     self.link.respond(*subscriber, Ok(audio_data.clone()));

src/player.rs

@@ -1,4 +1,4 @@
-use crate::agents::audio_agent::{self, AudioAgent};
+use crate::agents::audio_agent::{self, AudioAgent, AudioData};
 use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 use cpal::{Device, SampleFormat, SampleRate, Stream, StreamConfig};
 use yew::agent::Dispatcher;
@@ -14,11 +14,13 @@ pub struct Player {
     link: ComponentLink<Self>,
     status: Status,
     stream: Option<Stream>,
-    audio_agent: Dispatcher<AudioAgent>,
+    audio_agent: Box<dyn Bridge<AudioAgent>>,
+    audio_data: Option<AudioData>,
 }
 
 pub enum Msg {
     Play,
+    AudioAgentMessage(Result<AudioData, String>),
 }
 
 impl Component for Player {
@@ -26,11 +28,14 @@ impl Component for Player {
     type Properties = ();
 
     fn create(_: Self::Properties, link: ComponentLink<Self>) -> Self {
+        let cb = link.callback(Msg::AudioAgentMessage);
+
         Self {
             link,
             status: Status::Stopped,
             stream: None,
-            audio_agent: AudioAgent::dispatcher(),
+            audio_agent: AudioAgent::bridge(cb),
+            audio_data: None,
         }
     }
 
@@ -39,6 +44,8 @@ impl Component for Player {
     fn update(&mut self, msg: Self::Message) -> ShouldRender {
         match msg {
             Msg::Play => self.handle_play_button_clicked(),
+            Msg::AudioAgentMessage(Ok(audio_data)) => self.handle_samples_loaded(audio_data),
+            Msg::AudioAgentMessage(Err(err)) => self.handle_samples_loaded_error(&err),
         }
     }
 
@@ -56,7 +63,20 @@ impl Component for Player {
 }
 
 impl Player {
+    fn handle_samples_loaded(&mut self, audio_data: AudioData) -> ShouldRender {
+        ConsoleService::log("Player: samples loaded");
+        self.audio_data = Some(audio_data);
+        true
+    }
+
+    fn handle_samples_loaded_error(&mut self, err: &str) -> ShouldRender {
+        ConsoleService::log(&format!("Player: error loading samples: {:?}", err));
+        self.audio_data = None;
+        false
+    }
+
     fn play(&mut self) {
+        if let Some(audio_data) = &self.audio_data {
             let host = cpal::default_host();
             let device = host.default_output_device().unwrap();
 
@@ -71,15 +91,22 @@ impl Player {
             ConsoleService::log(&format!("Using output config: {:?}", config));
 
             let stream = match config.sample_format() {
-            SampleFormat::F32 => Player::run::<f32>(&device, &config.into()),
-            SampleFormat::I16 => Player::run::<i16>(&device, &config.into()),
-            SampleFormat::U16 => Player::run::<u16>(&device, &config.into()),
+                SampleFormat::F32 => {
+                    Player::run::<f32>(&device, &config.into(), audio_data.clone())
+                }
+                SampleFormat::I16 => {
+                    Player::run::<i16>(&device, &config.into(), audio_data.clone())
+                }
+                SampleFormat::U16 => {
+                    Player::run::<u16>(&device, &config.into(), audio_data.clone())
+                }
             };
 
             self.stream = Some(stream);
         }
+    }
 
-    fn run<T>(device: &Device, config: &StreamConfig) -> Stream
+    fn run<T>(device: &Device, config: &StreamConfig, audio_data: AudioData) -> Stream
     where
         T: cpal::Sample,
     {