at least it complies

src/main.rs

@@ -25,7 +25,7 @@ struct Flags {
 fn main() {
    let flags = Flags::parse();
 
-   let w = new_whisper(flags.model, flags.threads).unwrap();
+   let w = new_whisper(flags.model, flags.threads, Handler{}).unwrap();
    let stream_retain = (flags.stream_retain * 16_000.0) as usize;
    let stream_step = Duration::new(flags.stream_step, 0);
    match flags.wav {
@@ -38,10 +38,7 @@ fn main() {
          let data16 = data.as_sixteen().expect("wav is not 32bit floats");
          let audio_data = &whisper_rs::convert_integer_to_float_audio(&data16);
 
-         w.transcribe(&audio_data,
-            |result| println!("{}", result),
-            |err| eprintln!("failed to transcribe wav: {}", err),
-         );
+         w.transcribe(&audio_data);
       },
       None => {
          let mut buffer = vec![];
@@ -49,13 +46,7 @@ fn main() {
          new_listener().listen(move |data: Vec<f32>| {
             data.iter().for_each(|x| buffer.push(*x));
             if Instant::now() - last > stream_step {
-               w.transcribe(&buffer,
-                  |result| {
-                     eprintln!("{}", chrono::Local::now());
-                     println!("{}", result);
-                  },
-                  |err| eprintln!("failed to transcribe stream: {}", err),
-               );
+               w.transcribe(&buffer);
 
                for i in stream_retain..buffer.len() {
                   buffer[i - stream_retain] = buffer[i]
@@ -69,29 +60,65 @@ fn main() {
 }
 
 struct Whisper {
-   ctx: WhisperContext,
-   threads: i32,
+   jobs: std::sync::mpsc::SyncSender<AWhisper>,
 }
 
-fn new_whisper(model_path: String, threads: i32) -> Result<Whisper, String> {
-   match WhisperContext::new(&model_path) {
-      Ok(ctx) => Ok(Whisper{
-         ctx: ctx,
-         threads: threads,
-      }),
-      Err(msg) => Err(format!("failed to load {}: {}", model_path, msg)),
+struct WhisperEngine {
+   ctx: WhisperContext,
+   threads: i32,
+   handler: Handler,
+}
+
+fn new_whisper(model_path: String, threads: i32, handler: Handler) -> Result<Whisper, String> {
+   match new_whisper_engine(model_path, threads, handler) {
+      Ok(engine) => {
+         let (send, recv) = std::sync::mpsc::sync_channel(100);
+         thread::spawn(move || { engine.transcribe_asyncs(recv); });
+         Ok(Whisper{jobs: send})
+      },
+      Err(msg) => Err(format!("failed to initialize engine: {}", msg)),
    }
 }
 
 impl Whisper {
-   fn transcribe(&self, data: &Vec<f32>, on_success: impl Fn(String), on_error: impl Fn(String)) {
-      match self._transcribe(&data) {
-         Ok(result) => on_success(result),
-         Err(msg) => on_error(format!("failed to transcribe: {}", msg)),
-      };
+   fn transcribe(&self, data: &Vec<f32>) {
+      self.transcribe_async(data).unwrap();
+      // TODO block
    }
 
-   fn _transcribe(&self, data: &Vec<f32>) -> Result<String, WhisperError> {
+   fn transcribe_async(&self, data: &Vec<f32>) -> Result<(), String> {
+      match self.jobs.try_send(AWhisper{
+         data: data.clone().to_vec(),
+      }) {
+         Ok(_) => Ok(()),
+         Err(msg) => Err(format!("failed to enqueue transcription: {}", msg)),
+      }
+   }
+}
+
+fn new_whisper_engine(model_path: String, threads: i32, handler: Handler) -> Result<WhisperEngine, String> {
+   match WhisperContext::new(&model_path) {
+      Ok(ctx) => Ok(WhisperEngine{ctx: ctx, threads: threads, handler: handler}),
+      Err(msg) => Err(format!("failed to load {}: {}", model_path, msg)),
+   }
+}
+
+impl WhisperEngine {
+   fn transcribe_asyncs(&self, recv: std::sync::mpsc::Receiver<AWhisper>) {
+      loop {
+         match recv.recv() {
+            Ok(job) => {
+               match self.transcribe(&job.data) {
+                  Ok(result) => self.handler.on_success(result),
+                  Err(msg) => self.handler.on_error(format!("failed to transcribe: {}", msg)),
+               };
+            },
+            Err(_) => return,
+         };
+      }
+   }
+
+   fn transcribe(&self, data: &Vec<f32>) -> Result<String, WhisperError> {
       let mut params = FullParams::new(SamplingStrategy::Greedy { best_of: 0 });
       params.set_no_context(true);
       params.set_n_threads(self.threads);
@@ -117,6 +144,22 @@ impl Whisper {
    }
 }
 
+struct AWhisper {
+   data: Vec<f32>,
+}
+
+struct Handler {}
+
+impl Handler {
+   fn on_success(&self, result: String) {
+      eprintln!("{}", chrono::Local::now());
+      println!("{}", result);
+   }
+   fn on_error(&self, msg: String) {
+      eprintln!("error: {}", msg);
+   }
+}
+
 struct Listener {
 }