Struct ArenaRegion 

pub struct ArenaRegion { /* private fields */ }

A contiguous slab of memory with a bump pointer.

Memory is never freed individually. Call reset to reclaim the entire region at once.

Implementations

impl ArenaRegion

pub fn new(capacity: usize) -> Self

Create a new region with capacity bytes pre-allocated.

pub fn allocate(&mut self, size: usize) -> Option<(usize, usize)>

Bump-allocate size bytes aligned to ARENA_ALIGN.

Returns Some((start, end)) where the range [start, end) inside slab is exclusively owned by the caller until reset is called. Returns None if there is insufficient space.

pub fn remaining(&self) -> usize

Bytes still available for allocation (before alignment waste).

pub fn utilization(&self) -> f64

Fraction of capacity that has been allocated ([0.0, 1.0]).

Returns 0.0 for a zero-capacity region to avoid division by zero.

pub fn reset(&mut self)

Reset the bump pointer to zero, logically freeing all allocations.

This does not release the backing Vec memory.

pub fn slab(&self) -> &[u8]

Immutable view of the backing slab.

pub fn slab_mut(&mut self) -> &mut [u8]

Mutable view of the backing slab.

pub fn capacity(&self) -> usize

Total capacity in bytes.

pub fn offset(&self) -> usize

Current bump-pointer offset.

Trait Implementations

impl Debug for ArenaRegion

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

Formats the value using the given formatter.