Struct RegisteredBufferPool 

pub struct RegisteredBufferPool { /* private fields */ }

A pre-registered buffer pool for io_uring operations.

Buffers are registered with the kernel once at creation time, eliminating the per-operation buffer mapping overhead that would otherwise occur.

Example

use laminar_core::io_uring::RegisteredBufferPool;

let mut pool = RegisteredBufferPool::new(&mut ring, 64 * 1024, 256)?;

// Acquire a buffer
let (idx, buf) = pool.acquire()?;
buf[..5].copy_from_slice(b"hello");

// Use the buffer for I/O
pool.submit_write_fixed(fd, idx, 0, 5)?;

// After completion, release the buffer
pool.release(idx);

Implementations

impl RegisteredBufferPool

pub fn new( ring: &mut IoUring, buffer_size: usize, buffer_count: usize, ) -> Result<Self, IoUringError>

Create a new buffer pool and register it with the kernel.

Arguments

• ring - The io_uring instance to register buffers with
• buffer_size - Size of each buffer in bytes
• buffer_count - Number of buffers to allocate

Errors

Returns an error if buffer registration fails.

pub fn acquire(&mut self) -> Result<(u16, &mut [u8]), IoUringError>

Acquire a buffer from the pool.

Returns the buffer index and a mutable reference to the buffer.

Errors

Returns an error if no buffers are available.

pub fn try_acquire(&mut self) -> Option<(u16, &mut [u8])>

Try to acquire a buffer without blocking.

Returns None if no buffers are available.

pub fn release(&mut self, buf_index: u16)

Release a buffer back to the pool.

The buffer must not be in-flight (submitted to io_uring but not yet completed). In debug builds, this is checked via assertion.

Panics

Panics in debug builds if the buffer index is invalid or the buffer is still in-flight.

pub fn mark_in_flight(&mut self, buf_index: u16)

Mark a buffer as in-flight (submitted to io_uring).

Call this after submitting a read/write operation that uses this buffer. Call Self::complete_in_flight when the CQE arrives.

pub fn complete_in_flight(&mut self, buf_index: u16)

Mark a buffer as no longer in-flight (CQE received).

pub fn get(&self, buf_index: u16) -> Result<&[u8], IoUringError>

Get a reference to a buffer by index.

Errors

Returns an error if the index is invalid.

pub fn get_mut(&mut self, buf_index: u16) -> Result<&mut [u8], IoUringError>

Get a mutable reference to a buffer by index.

Errors

Returns an error if the index is invalid.

pub fn submit_read_fixed( &mut self, ring: &mut IoUring, fd: RawFd, buf_index: u16, offset: u64, len: u32, ) -> Result<u64, IoUringError>

Submit a read operation using a registered buffer.

The data will be read into the buffer at the given index.

Arguments

• ring - The io_uring instance
• fd - File descriptor to read from
• buf_index - Index of the registered buffer
• offset - File offset to read from
• len - Number of bytes to read

Returns

The user_data value that will identify this operation in completions.

Errors

Returns an error if the submission queue is full.

pub fn submit_write_fixed( &mut self, ring: &mut IoUring, fd: RawFd, buf_index: u16, offset: u64, len: u32, ) -> Result<u64, IoUringError>

Submit a write operation using a registered buffer.

The data in the buffer at the given index will be written.

Arguments

• ring - The io_uring instance
• fd - File descriptor to write to
• buf_index - Index of the registered buffer
• offset - File offset to write to
• len - Number of bytes to write

Returns

The user_data value that will identify this operation in completions.

Errors

Returns an error if the submission queue is full.

pub const fn buffer_size(&self) -> usize

Get the size of each buffer.

pub const fn total_count(&self) -> usize

Get the total number of buffers.

pub fn available_count(&self) -> usize

Get the number of available buffers.

pub const fn acquired_count(&self) -> usize

Get the number of acquired buffers.

pub fn is_exhausted(&self) -> bool

Check if the pool is exhausted.

pub fn stats(&self) -> BufferPoolStats

Get statistics about the buffer pool.

Trait Implementations

impl Drop for RegisteredBufferPool

fn drop(&mut self)

Executes the destructor for this type.