Struct IdPool 

pub struct IdPool { /* private fields */ }

Keeps track of free ids within a specified range, handles requests and returns of ids based on internal state.

Internally, a collection of free id ranges is stored. On a request for an id from the pool, the lowest available number will be returned to the caller. Ids can also be returned to the pool to be reused by subsequent id requests.

Examples

// initialize a new pool
let mut pool = IdPool::new();
// request some ids
assert_eq!(Some(1), pool.request_id());
assert_eq!(Some(2), pool.request_id());
assert_eq!(Some(3), pool.request_id());
// return the first id
assert_eq!(Ok(()), pool.return_id(1));
// next request returns recycled first id
assert_eq!(Some(1), pool.request_id());
// subsequent request returns the next free value
assert_eq!(Some(4), pool.request_id());

Implementations

impl IdPool

pub fn new() -> Self

Creates a new IdPool with a default range, which starts at 1 and ends at Num::MAX.

pub fn new_ranged(range: Range<usize>) -> Self

Creates a new IdPool with the given range.

pub fn used_count(&self) -> usize

Gets the current count of used ids.

pub fn request_id(&mut self) -> Option<usize>

Returns a new id or None if there are no free ids in the pool.

pub fn return_id(&mut self, id: usize) -> Result<(), usize>

Returns an id to the pool or Err(Num) if the id is already in the pool.

Trait Implementations

impl Clone for IdPool

fn clone(&self) -> IdPool

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for IdPool

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

Formats the value using the given formatter.