Avoid dropping the variable when wrapped into a struct - rust

Question

I have a Rodio's Sink wrapper in HAudioSink. I also implement a try_new_from_haudio function that, in short, creates a Sink instance, wrap it in HAudioSink and already starts playing the first audio.
In Sink's docs it states: "Dropping the Sink stops all sounds. You can use detach if you want the sounds to continue playing". So when try_new_from_haudiois returning, it drops the original sink and the sound is stopping when it shouldn't.
So my question here is: what should I do to avoid it dropping when I create an instance of HAudioSink? Is ManuallyDrop the way to go?
struct HAudioSink {
sink: Sink,
}
impl HAudioSink {
pub fn try_new_from_haudio<T>(haudio: HAudio<T>) -> HResult<Self>
where
T: NativeType + Float + ToPrimitive,
{
let (_stream, stream_handle) = OutputStream::try_default()?;
let sink = Sink::try_new(&stream_handle).unwrap();
let nchannels = haudio.nchannels();
let nframes = haudio.nframes();
let sr = haudio.sr();
let mut data_interleaved: Vec<f32> = Vec::with_capacity(nchannels * nframes);
let values = haudio
.inner()
.inner()
.values()
.as_any()
.downcast_ref::<PrimitiveArray<T>>()
.unwrap();
for f in 0..nframes {
for ch in 0..nchannels {
data_interleaved.push(values.value(f + ch * nframes).to_f32().unwrap());
}
}
let source = SamplesBuffer::new(u16::try_from(nchannels).unwrap(), sr, data_interleaved);
sink.append(source);
Ok(HAudioSink { sink })
}
// Sleeps the current thread until the sound ends.
pub fn sleep_until_end(&self) {
self.sink.sleep_until_end();
}
}
#[cfg(test)]
mod tests {
use super::*;
//this test doesn't work
#[test]
fn play_test() {
let sink = HAudioSink::try_new_from_file("../testfiles/gs-16b-2c-44100hz.wav").unwrap();
sink.append_from_file("../testfiles/gs-16b-2c-44100hz.wav")
.unwrap();
sink.sleep_until_end();
}
}
If I put sink.sleep_until_end() inside try_new_from_haudio, just before returning Ok, it works.
check the following link for the reproducible example of this issue: https://github.com/RustAudio/rodio/issues/476

Answer 1

The problem is that for the _stream too "If this is dropped playback will end & attached OutputStreamHandles will no longer work."
see the docs on OutputStream. So you have to store it alongside your Sink:
pub struct SinkWrapper {
pub sink: Sink,
pub stream: OutputStream,
}
impl SinkWrapper {
pub fn new() -> Self {
let (stream, stream_handle) = OutputStream::try_default().unwrap();
let sink = Sink::try_new(&stream_handle).unwrap();
// Add a dummy source of the sake of the example.
let source = SineWave::new(440.0)
.take_duration(Duration::from_secs_f32(1.))
.amplify(2.);
sink.append(source);
Self { sink, stream }
}
}