Struct BufferPool

Source

pub struct BufferPool {
    pub buffers: Vec<PooledBuffer>,
    pub next_id: u64,
    /* private fields */
}

Expand description

A pool of frame buffers identified by integer IDs.

Buffers are acquired by ID and released back to the pool by ID. When constructed with BufferPool::with_pressure, the pool monitors its fill ratio and fires registered callbacks on level transitions.

Fields§

§buffers: Vec<PooledBuffer>

Managed buffers.

§next_id: u64

Counter for assigning unique IDs to new buffers.

Implementations§

Source §

impl BufferPool

Source

pub fn new(count: usize, buf_size: usize) -> Self

Creates a new BufferPool with count buffers each of buf_size bytes.

All buffers share pool_id = 0 and default alignment of 64. No pressure thresholds or callbacks are configured.

Source

pub fn with_pressure( count: usize, buf_size: usize, thresholds: PressureThresholds, ) -> Self

Creates a BufferPool with memory pressure monitoring enabled.

See PressureThresholds for details on watermark configuration.

Source

pub fn add_pressure_callback(&mut self, cb: MemoryPressureCallback)

Registers a callback to be invoked whenever the pressure level transitions.

The callback receives the new MemoryPressureLevel as its argument. Multiple callbacks may be registered and are called in registration order.

Source

pub fn current_pressure_level(&self) -> MemoryPressureLevel

Returns the current memory pressure level.

If no thresholds are configured, always returns MemoryPressureLevel::Low.

Source

pub fn acquire(&mut self) -> Option<u64>

Acquires an available buffer and returns its ID.

Returns None if no buffer is free. Triggers pressure notification after the acquisition.

Source

pub fn release(&mut self, id: u64)

Releases the buffer with the given id back to the pool.

If the ID is not found this is a no-op. Triggers pressure notification after the release.

Source

pub fn shrink_to(&mut self, target_count: usize) -> usize

Removes free (not in-use) buffers until the pool has at most target_count total buffers.

Only idle buffers are removed; buffers currently in use are never evicted. Returns the number of buffers that were removed.

§Example

use oximedia_core::buffer_pool::BufferPool;

let mut pool = BufferPool::new(8, 64);
let removed = pool.shrink_to(4);
assert_eq!(removed, 4);
assert_eq!(pool.total_count(), 4);