apalis_core/mq/mod.rs
//! # Message queue
//!
//! The `mq` module provides an abstraction for representing a message queue that supports pushing and consuming messages. It defines the MessageQueue trait, which can be implemented by different types of message queues.
use futures::Future;
/// Represents a message queue that can be pushed and consumed.
pub trait MessageQueue<Message> {
/// The error produced by the queue
type Error;
/// Enqueues a message to the queue.
fn enqueue(&mut self, message: Message)
-> impl Future<Output = Result<(), Self::Error>> + Send;
/// Attempts to dequeue a message from the queue.
/// Returns `None` if the queue is empty.
fn dequeue(&mut self) -> impl Future<Output = Result<Option<Message>, Self::Error>> + Send;
/// Returns the current size of the queue.
fn size(&mut self) -> impl Future<Output = Result<usize, Self::Error>> + Send;
}