Struct IndexAllocator 

pub struct IndexAllocator { /* private fields */ }

Allocator for session indices within a single transport.

Manages a pool of random 32-bit indices, tracking which are in use to prevent collision. Thread-safe for single-threaded async use.

Implementations

impl IndexAllocator

pub fn new() -> Self

Create a new index allocator.

pub fn with_max_attempts(max_attempts: usize) -> Self

Create with a specific max attempts limit.

pub fn allocate(&mut self) -> Result<SessionIndex, IndexError>

Allocate a new random index.

Returns a cryptographically random 32-bit index that is not currently in use. Returns error if allocation fails after max_attempts tries (indicates too many active sessions).

pub fn free(&mut self, index: SessionIndex) -> Result<(), IndexError>

Free an index, returning it to the available pool.

Returns error if the index was not allocated.

pub fn is_allocated(&self, index: SessionIndex) -> bool

Check if an index is currently allocated.

pub fn count(&self) -> usize

Number of currently allocated indices.

pub fn is_empty(&self) -> bool

Check if the allocator is empty (no indices allocated).

pub fn reserve(&mut self, index: SessionIndex) -> Result<(), IndexError>

Reserve a specific index (for testing or migration).

Returns error if the index is already in use.

pub fn clear(&mut self)

Clear all allocations (use with caution).

Trait Implementations

impl Debug for IndexAllocator

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

Formats the value using the given formatter.

impl Default for IndexAllocator

fn default() -> Self

Returns the “default value” for a type.