Struct IO 

pub struct IO<'a, S: Copy>(/* private fields */);

Sample format dependent struct for reading from and writing data to a PCM. Also implements std::io::Read and std::io::Write.

Note: Only one IO object is allowed in scope at a time (for mmap safety).

Implementations

impl<'a, S: Copy> IO<'a, S>

pub fn writei(&self, buf: &[S]) -> Result<usize>

On success, returns number of frames written. (Multiply with number of channels to get number of items in buf successfully written.)

pub fn readi(&self, buf: &mut [S]) -> Result<usize>

On success, returns number of frames read. (Multiply with number of channels to get number of items in buf successfully read.)

pub unsafe fn writen(&self, bufs: &[*const S], frames: usize) -> Result<usize>

Write non-interleaved frames to pcm. On success, returns number of frames written.

Safety

Caller must ensure that the length of bufs is at least the number of channels, and that each element of bufs is a valid pointer to an array of at least frames length.

pub unsafe fn readn(&self, bufs: &mut [*mut S], frames: usize) -> Result<usize>

Read non-interleaved frames to pcm. On success, returns number of frames read.

Safety

Caller must ensure that the length of bufs is at least the number of channels, and that each element of bufs is a valid pointer to an array of at least frames length.

pub fn mmap<F: FnOnce(&mut [S]) -> usize>( &self, frames: usize, func: F, ) -> Result<usize>

Wrapper around snd_pcm_mmap_begin and snd_pcm_mmap_commit.

You can read/write into the sound card’s buffer during the call to the closure. According to alsa-lib docs, you should call avail_update before calling this function.

All calculations are in frames, i e, the closure should return number of frames processed. Also, there might not be as many frames to read/write as requested, and there can even be an empty buffer supplied to the closure.

Note: This function works only with interleaved access mode.

Trait Implementations

impl<'a, S: Debug + Copy> Debug for IO<'a, S>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a, S: Copy> Drop for IO<'a, S>

fn drop(&mut self)

Executes the destructor for this type.

impl<'a, S: Copy> Read for IO<'a, S>

Available on crate feature std only.

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

fn read_array<const N: usize>(&mut self) -> Result<[u8; N], Error>

where Self: Sized,

🔬This is a nightly-only experimental API. (read_array)

Read and return a fixed array of bytes from this source.

impl<'a, S: Copy> Write for IO<'a, S>

Available on crate feature std only.

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn write_vectored(&mut self, bufs: &[IoSlice<'_>]) -> Result<usize, Error>

Like write, except that it writes from a slice of buffers.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.