Struct Queue 

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

Queue that is limited in size and supports resizing.

This queue implementation has the following characteristics:

• Resizable (deadqueue::resizable::Queue)
• Based on deadqueue::unlimited::Queue
• Has limited capacity with back pressure on push
• Supports resizing
• Enabled via the resizable feature in your Cargo.toml

Implementations

impl<T> Queue<T>

pub fn new(max_size: usize) -> Self

Create new empty queue

pub async fn pop(&self) -> T

Get an item from the queue. If the queue is currently empty this method blocks until an item is available.

pub fn try_pop(&self) -> Option<T>

Try to get an item from the queue. If the queue is currently empty return None instead.

pub async fn push(&self, item: T)

Push an item into the queue

pub fn try_push(&self, item: T) -> Result<(), T>

Try to push an item to the queue. If the queue is currently full return the object as Err<T>.

pub fn capacity(&self) -> usize

Get capacity of the queue (maximum number of items queue can store).

pub fn len(&self) -> usize

Get current length of queue (number of items currently stored).

pub fn is_empty(&self) -> bool

Returns true if the queue is empty.

pub fn is_full(&self) -> bool

Returns true if the queue is full. Note: this can give an incorrect result if a simultaneous push/pop and resize ocurr while this function is executing. try_push() is the reccomended and safer mechanism in most circumstances. This method is provided as a convenience API.

pub fn available(&self) -> isize

The number of available items in the queue. If there are no items in the queue this number can become negative and stores the number of futures waiting for an item.

pub async fn wait_full(&self)

Await until the queue is full.

pub fn subscribe_full(&self) -> Receiver

Get a Receiver object that can repeatedly be awaited for queue-full notifications.

pub async fn wait_empty(&self)

Await until the queue is empty.

pub fn subscribe_empty(&self) -> Receiver

Get a Receiver object that can repeatedly be awaited for queue-empty notifications.

pub async fn resize(&self, target_capacity: usize)

Resize queue. This increases or decreases the queue capacity accordingly.

Note: Increasing the capacity of a queue happens without blocking unless a resize operation is already in progress. Decreasing the capacity can block if there are futures waiting to push items to the queue.

Trait Implementations

impl<T> Debug for Queue<T>

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

Formats the value using the given formatter.

impl<T> FromIterator<T> for Queue<T>

fn from_iter<I: IntoIterator<Item = T>>(iter: I) -> Self

Creates a value from an iterator.