Struct SlabAllocator

Source

pub struct SlabAllocator<T> { /* private fields */ }

Expand description

A fixed-slot slab allocator for type T.

§Example

use oximedia_cache::slab_allocator::SlabAllocator;

let mut alloc: SlabAllocator<Vec<u8>> = SlabAllocator::new(16);
let h = alloc.allocate(vec![0u8; 1024]).unwrap();
assert_eq!(alloc.get(h).unwrap().len(), 1024);
alloc.free(h).unwrap();

Implementations§

Source §

impl<T> SlabAllocator<T>

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pub fn new(slab_capacity: usize) -> Self

Create a new allocator that allocates slabs of slab_capacity slots.

A capacity of 0 is treated as 1.

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pub fn allocate(&mut self, value: T) -> Result<SlotHandle, SlabError>

Allocate a slot for value.

Returns a SlotHandle that can be used to retrieve or free the value.

If no free slots are available a new slab is allocated.

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pub fn free(&mut self, handle: SlotHandle) -> Result<(), SlabError>

Free the slot identified by handle, making it available for reuse.

Returns Err if the handle is out of range or the slot is already free.

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pub fn get(&self, handle: SlotHandle) -> Result<&T, SlabError>

Return an immutable reference to the value at handle.

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pub fn get_mut(&mut self, handle: SlotHandle) -> Result<&mut T, SlabError>

Return a mutable reference to the value at handle.

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pub fn compact(&mut self) -> usize

Compact the allocator by removing fully-empty slabs.

Returns the number of slabs reclaimed. Note that this invalidates all existing SlotHandles whose slab index ≥ the first reclaimed slab. Callers must not use stale handles after compaction.

In practice you should call compact only during a cache quiesce window (e.g. on process idle or periodic maintenance).

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