Struct a10::io::ReadBufPool

pub struct ReadBufPool { /* private fields */ }

A read buffer pool.

This is a special buffer pool that shares its buffers with the kernel. The buffer pool is used by the kernel in read(2) and recv(2) like calls. Instead of user space having to select a buffer before issueing the read call, the kernel will select a buffer from the pool when it’s ready for reading. This avoids the need to have as many buffers as concurrent read calls.

As a result of this the returned buffer, ReadBuf, is somewhat limited. For example it can’t grow beyond the pool’s buffer size. However it can be used in write calls like any other buffer.

Implementations

impl ReadBufPool

pub fn new( sq: SubmissionQueue, pool_size: u16, buf_size: u32 ) -> Result<ReadBufPool>

Create a new buffer pool.

pool_size must be a power of 2, with a maximum of 2^15 (32768). buf_size is the maximum capacity of the buffer. Note that buffer can’t grow beyond this capacity.

pub fn get(&self) -> ReadBuf

Get a buffer reference to this pool.

This can only be used in read I/O operations, such as AsyncFd::read, but it won’t yet select a buffer to use. This is done by the kernel once it actually has data to write into the buffer. Before it’s used in a read call the returned buffer will be empty and can’t be resized, it’s effecitvely useless before a read call.

Trait Implementations

impl Clone for ReadBufPool

fn clone(&self) -> ReadBufPool

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ReadBufPool

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

Formats the value using the given formatter.