cpal/src/platform/windows/asio/stream.rs

extern crate asio_sys as sys;
extern crate asio_utils as au;

use std;
use Format;
use CreationError;
use StreamData;
use std::marker::PhantomData;
use super::Device;
use std::cell::Cell;
use UnknownTypeOutputBuffer;
use UnknownTypeInputBuffer;
use std::sync::{Arc, Mutex};
use std::mem;
use std::sync::atomic::{AtomicUsize, Ordering};
use SampleFormat;

pub struct EventLoop {
    asio_streams: Arc<Mutex<sys::AsioStreams>>,
    cpal_streams: Arc<Mutex<Vec<Option<Stream>>>>,
    stream_count: AtomicUsize,
    callbacks: Arc<Mutex<Vec<&'static mut (FnMut(StreamId, StreamData) + Send)>>>,
}

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct StreamId(usize);

pub struct InputBuffer<'a, T: 'a> {
    buffer: &'a [T],
}
pub struct OutputBuffer<'a, T: 'a> {
    buffer: &'a mut [T],
}

enum Stream{
    Input,
    Output,
}

#[derive(Default)]
struct I16Buffer{
    cpal: Vec<i16>,
    channel: Vec<Vec<i16>>,
}
#[derive(Default)]
struct U16Buffer{
    cpal: Vec<u16>,
    channel: Vec<Vec<u16>>,
}
#[derive(Default)]
struct F32Buffer{
    cpal: Vec<f32>,
    channel: Vec<Vec<f32>>,
}
struct Buffers {
    i16_buff: I16Buffer,
    u16_buff: U16Buffer,
    f32_buff: F32Buffer,
}

impl EventLoop {
    pub fn new() -> EventLoop {
        EventLoop {
            asio_streams: Arc::new(Mutex::new(sys::AsioStreams{input: None, output: None})),
            cpal_streams: Arc::new(Mutex::new(Vec::new())),
            stream_count: AtomicUsize::new(0),
            callbacks: Arc::new(Mutex::new(Vec::new())),
        }
    }

    fn get_input_stream(&self, drivers: &sys::Drivers, num_channels: usize) -> Result<usize, CreationError> {
            let ref mut streams = *self.asio_streams.lock().unwrap();
            match streams.input {
                Some(ref input) => Ok(input.buffer_size as usize),
                None => {
                    let output = streams.output.take();
                    drivers.prepare_input_stream(output, num_channels)
                        .map(|new_streams| {
                            let bs = match new_streams.input {
                                Some(ref inp) => inp.buffer_size as usize,
                                None => unreachable!(),
                            };
                            *streams = new_streams;
                            bs
                        })
                        .map_err(|ref e| {
                            println!("Error preparing stream: {}", e);
                            CreationError::DeviceNotAvailable
                        })
                }
            }
    }
    
    fn get_output_stream(&self, drivers: &sys::Drivers, num_channels: usize) -> Result<usize, CreationError> {
            let ref mut streams = *self.asio_streams.lock().unwrap();
            match streams.output {
                Some(ref output) => Ok(output.buffer_size as usize),
                None => {
                    let input = streams.input.take();
                    drivers.prepare_output_stream(input, num_channels)
                        .map(|new_streams| {
                            let bs = match new_streams.output {
                                Some(ref out) => out.buffer_size as usize,
                                None => unreachable!(),
                            };
                            *streams = new_streams;
                            bs
                        })
                        .map_err(|ref e| {
                            println!("Error preparing stream: {}", e);
                            CreationError::DeviceNotAvailable
                        })
                },
            }
    }

    pub fn build_input_stream(
        &self,
        device: &Device,
        format: &Format,
        ) -> Result<StreamId, CreationError> {
            let Device {
                drivers,
                ..
            } = device;
        let num_channels = format.channels.clone();
        let stream_type = drivers.get_data_type().expect("Couldn't load data type");
        self.get_input_stream(&drivers, num_channels as usize).map(|stream_buffer_size| {
            let cpal_num_samples = stream_buffer_size * num_channels as usize;
            let count = self.stream_count.load(Ordering::SeqCst);
            self.stream_count.store(count + 1, Ordering::SeqCst);
            let asio_streams = self.asio_streams.clone();
            let callbacks = self.callbacks.clone();
            let bytes_per_channel = format.data_type.sample_size();
            
            // Create buffers 
            let channel_len = cpal_num_samples 
                / num_channels as usize;
            
            
            let mut buffers = match format.data_type{
                SampleFormat::I16 => {
                    Buffers{
                        i16_buff: I16Buffer{
                        cpal: vec![0 as i16; cpal_num_samples],
                        channel: (0..num_channels)
                        .map(|_| Vec::with_capacity(channel_len))
                        .collect()},
                        u16_buff: U16Buffer::default(),
                        f32_buff: F32Buffer::default(),
                    }
                }
                SampleFormat::U16 => {
                    Buffers{
                        i16_buff: I16Buffer::default(),
                        u16_buff: U16Buffer{
                        cpal: vec![0 as u16; cpal_num_samples],
                        channel: (0..num_channels)
                        .map(|_| Vec::with_capacity(channel_len))
                        .collect()},
                        f32_buff: F32Buffer::default(),
                    }
                }
                SampleFormat::F32 => {
                    Buffers{
                        i16_buff: I16Buffer::default(),
                        u16_buff: U16Buffer::default(),
                        f32_buff: F32Buffer{
                        cpal: vec![0 as f32; cpal_num_samples],
                        channel: (0..num_channels)
                        .map(|_| Vec::with_capacity(channel_len))
                        .collect()},
                    }
                }
            };

            sys::set_callback(move |index| unsafe {
                if let Some(ref asio_stream) = asio_streams.lock().unwrap().input {
                    // Number of samples needed total
                    let mut callbacks = callbacks.lock().unwrap();

                    // Assuming only one callback, probably needs to change
                    match callbacks.first_mut() {
                        Some(callback) => {
                            macro_rules! try_callback {
                                ($SampleFormat:ident,
                                    $SampleType:ty,
                                    $SampleTypeIdent:ident,
                                    $AsioType:ty,
                                    $AsioTypeIdent:ident,
                                    $Buffers:expr,
                                    $BuffersType:ty,
                                    $BuffersTypeIdent:ident
                                    ) => {

                                    // For each channel write the cpal data to
                                    // the asio buffer
                                    // Also need to check for Endian

                                    for (i, channel) in $Buffers.channel.iter_mut().enumerate(){
                                        let buff_ptr = asio_stream
                                                        .buffer_infos[i]
                                                        .buffers[index as usize] as *mut $AsioType;
                                        let asio_buffer: &'static [$AsioType] =
                                            std::slice::from_raw_parts(
                                                buff_ptr,
                                                asio_stream.buffer_size as usize);
                                        for asio_s in asio_buffer.iter(){
                                            channel.push( (*asio_s as i64 *
                                                            ::std::$SampleTypeIdent::MAX as i64 /
                                                            ::std::$AsioTypeIdent::MAX as i64) as $SampleType);
                                        }
                                    }


                                    // interleave all the channels
                                    {
                                        let $BuffersTypeIdent {
                                            cpal: ref mut c_buffer,
                                            channel: ref mut channels,
                                        } = $Buffers;
                                        au::interleave(&channels, c_buffer);
                                        for c in channels.iter_mut() {
                                            c.clear();
                                        }
                                    }


                                    let buff = InputBuffer{
                                        buffer: &mut $Buffers.cpal,
                                    };
                                    callback(
                                        StreamId(count),
                                        StreamData::Input{
                                            buffer: UnknownTypeInputBuffer::$SampleFormat(
                                                        ::InputBuffer{
                                                            buffer: Some(super::super::InputBuffer::Asio(buff))
                                                        })
                                        }
                                        );
                                }
                            };
                            // Generic over types
                            // TODO check for endianess
                            match stream_type {
                                sys::AsioSampleType::ASIOSTInt32LSB => {
                                    try_callback!(I16, i16, i16, i32, i32, 
                                    buffers.i16_buff, I16Buffer, I16Buffer);
                                }
                                sys::AsioSampleType::ASIOSTInt16LSB => {
                                    try_callback!(I16, i16, i16, i16, i16, 
                                    buffers.i16_buff, I16Buffer, I16Buffer);
                                }
                                sys::AsioSampleType::ASIOSTFloat32LSB => {
                                    try_callback!(F32, f32, f32, f32, f32, 
                                    buffers.f32_buff, F32Buffer, F32Buffer);
                                }
                                sys::AsioSampleType::ASIOSTFloat64LSB => {
                                    try_callback!(F32, f32, f32, f64, f64, 
                                    buffers.f32_buff, F32Buffer, F32Buffer);
                                }
                                _ => println!("unsupported format {:?}", stream_type),
                            }
                        }
                        None => return (),
                    }
                }
            });
            self.cpal_streams.lock().unwrap().push(Some(Stream::Input));
            StreamId(count)
        })
    }

pub fn build_output_stream(
    &self,
    device: &Device,
    format: &Format,
    ) -> Result<StreamId, CreationError> {
    let Device {
        drivers,
        ..
    } = device;
    let num_channels = format.channels.clone();
    let stream_type = drivers.get_data_type().expect("Couldn't load data type");
    self.get_output_stream(&drivers, num_channels as usize).map(|stream_buffer_size| {
        let cpal_num_samples = stream_buffer_size * num_channels as usize;
        let count = self.stream_count.load(Ordering::SeqCst);
        self.stream_count.store(count + 1, Ordering::SeqCst);
        let asio_streams = self.asio_streams.clone();
        let callbacks = self.callbacks.clone();
        let bytes_per_channel = format.data_type.sample_size();
        // Create buffers 
        let channel_len = cpal_num_samples 
            / num_channels as usize;
        
        
        let mut re_buffers = match format.data_type{
            SampleFormat::I16 => {
                Buffers{
                    i16_buff: I16Buffer{
                    cpal: vec![0 as i16; cpal_num_samples],
                    channel: (0..num_channels)
                    .map(|_| Vec::with_capacity(channel_len))
                    .collect()},
                    u16_buff: U16Buffer::default(),
                    f32_buff: F32Buffer::default(),
                }
            }
            SampleFormat::U16 => {
                Buffers{
                    i16_buff: I16Buffer::default(),
                    u16_buff: U16Buffer{
                    cpal: vec![0 as u16; cpal_num_samples],
                    channel: (0..num_channels)
                    .map(|_| Vec::with_capacity(channel_len))
                    .collect()},
                    f32_buff: F32Buffer::default(),
                }
            }
            SampleFormat::F32 => {
                Buffers{
                    i16_buff: I16Buffer::default(),
                    u16_buff: U16Buffer::default(),
                    f32_buff: F32Buffer{
                    cpal: vec![0 as f32; cpal_num_samples],
                    channel: (0..num_channels)
                    .map(|_| Vec::with_capacity(channel_len))
                    .collect()},
                }
            }
        };

        sys::set_callback(move |index| unsafe {
            if let Some(ref asio_stream) = asio_streams.lock().unwrap().output {
                // Number of samples needed total
                let mut callbacks = callbacks.lock().unwrap();

                // Assuming only one callback, probably needs to change
                match callbacks.first_mut() {
                    Some(callback) => {
                        macro_rules! try_callback {
                            ($SampleFormat:ident,
                                $SampleType:ty,
                                $SampleTypeIdent:ident,
                                $AsioType:ty,
                                $AsioTypeIdent:ident,
                                $Buffers:expr,
                                $BuffersType:ty,
                                $BuffersTypeIdent:ident
                                ) => {
                                    let mut my_buffers = $Buffers;
                                // Buffer that is filled by cpal.
                                //let mut cpal_buffer: Vec<$SampleType> = vec![0 as $SampleType; cpal_num_samples];
                                //  Call in block because of mut borrow
                                {
                                    let buff = OutputBuffer{
                                        buffer: &mut my_buffers.cpal 
                                    };
                                    callback(
                                        StreamId(count),
                                        StreamData::Output{
                                            buffer: UnknownTypeOutputBuffer::$SampleFormat(
                                                        ::OutputBuffer{
                                                            target: Some(super::super::OutputBuffer::Asio(buff))
                                                        })
                                        }
                                        );
                                }
                                // Deinter all the channels
                                {
                                    let $BuffersTypeIdent {
                                        cpal: ref mut c_buffer,
                                        channel: ref mut channels,
                                    } = my_buffers;
                                    au::deinterleave(&c_buffer[..], channels);
                                }

                                // For each channel write the cpal data to
                                // the asio buffer
                                // TODO need to check for Endian
                                for (i, channel) in my_buffers.channel.iter().enumerate(){
                                    let buff_ptr = asio_stream
                                                    .buffer_infos[i]
                                                    .buffers[index as usize] as *mut $AsioType;
                                    let asio_buffer: &'static mut [$AsioType] =
                                        std::slice::from_raw_parts_mut(
                                            buff_ptr,
                                            asio_stream.buffer_size as usize);
                                    for (asio_s, cpal_s) in asio_buffer.iter_mut()
                                        .zip(channel){
                                            *asio_s = (*cpal_s as i64 *
                                                        ::std::$AsioTypeIdent::MAX as i64 /
                                                        ::std::$SampleTypeIdent::MAX as i64) as $AsioType;
                                        }

                                }
                            };
                        }
                        // Generic over types
                        // TODO check for endianess
                        match stream_type {
                            sys::AsioSampleType::ASIOSTInt32LSB => {
                                try_callback!(I16, i16, i16, i32, i32, 
                                &mut re_buffers.i16_buff, I16Buffer, I16Buffer);
                            }
                            sys::AsioSampleType::ASIOSTInt16LSB => {
                                try_callback!(I16, i16, i16, i16, i16, 
                                &mut re_buffers.i16_buff, I16Buffer, I16Buffer);
                            }
                            sys::AsioSampleType::ASIOSTFloat32LSB => {
                                try_callback!(F32, f32, f32, f32, f32, 
                                &mut re_buffers.f32_buff, F32Buffer, F32Buffer);
                            }
                            sys::AsioSampleType::ASIOSTFloat64LSB => {
                                try_callback!(F32, f32, f32, f64, f64, 
                                &mut re_buffers.f32_buff, F32Buffer, F32Buffer);
                            }
                            _ => println!("unsupported format {:?}", stream_type),
                        }
                    }
                    None => return (),
                }
            }
        });
        self.cpal_streams.lock().unwrap().push(Some(Stream::Output));
        StreamId(count)
    })
}


pub fn play_stream(&self, stream: StreamId) {
    sys::play();
}

pub fn pause_stream(&self, stream: StreamId) {
    sys::stop();
}

pub fn destroy_stream(&self, stream_id: StreamId) {
    let mut streams = self.cpal_streams.lock().unwrap();
    streams.get_mut(stream_id.0 - 1).take();
    let count = self.stream_count.load(Ordering::SeqCst);
    self.stream_count.store(count - 1, Ordering::SeqCst);
    if count == 1 {
        *self.asio_streams.lock().unwrap() = sys::AsioStreams{ output: None, input: None };
        sys::clean_up();
    }
}

pub fn run<F>(&self, mut callback: F) -> !
where
F: FnMut(StreamId, StreamData) + Send,
{
    let callback: &mut (FnMut(StreamId, StreamData) + Send) = &mut callback;
    self.callbacks
        .lock()
        .unwrap()
        .push(unsafe { mem::transmute(callback) });
    loop {
        // Might need a sleep here to prevent the loop being
        // removed in --release
    }
}
}

impl Drop for EventLoop {
    fn drop(&mut self) {
        sys::clean_up();
    }
}

impl<'a, T> InputBuffer<'a, T> {
    pub fn buffer(&self) -> &[T] {
        &self.buffer
    }
    pub fn finish(self) {
    }
}

impl<'a, T> OutputBuffer<'a, T> {
    pub fn buffer(&mut self) -> &mut [T] {
        &mut self.buffer
    }

    pub fn len(&self) -> usize {
        self.buffer.len()
    }

    pub fn finish(self) {}
}