queue-ext

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queue-ext provides extended features for queues, allowing conversion of the pop() function to a Stream and the push() function to a Sender. It serves as a foundational building block for async channel implementations.

Features

• Convert queue pop() into a Stream implementation
• Convert queue push() into a Sink/Sender implementation
• Type-erased channel API via queue_channel()
• QueueExt trait for easy integration with any queue type
• SendError type with full and disconnected variants
• Supports arbitrary queue backends (SegQueue, VecDeque, etc.)
• Thread-safe (Send + Sync)

Cargo Feature Flags

This crate has no Cargo feature flags. All functionality is enabled by default.

Basic Usage

use queue_ext::{QueueExt, Action, Reply};
use std::task::Poll;
use std::sync::Arc;
use crossbeam_queue::SegQueue;

let queue = Arc::new(SegQueue::new());
let (mut tx, mut rx) = queue.queue_channel::<i32, _, _, _>(
    |s, act| match act {
        Action::Send(val) => { s.push(val); Reply::Send(()) }
        Action::IsFull => Reply::IsFull(false),
        Action::IsEmpty => Reply::IsEmpty(s.is_empty()),
        Action::Len => Reply::Len(s.len()),
    },
    |s, _| match s.pop() {
        Some(m) => Poll::Ready(Some(m)),
        None => Poll::Pending,
    },
);

tx.try_send(42).unwrap();
assert_eq!(rx.is_closed(), false);

More Examples

• queue-ext-test.rs

Tests

cargo test -p queue-ext

41 tests covering Sink/Stream impl, SendError, drop semantics, and Send/Sync safety.

License

Licensed under either of Apache License 2.0 or MIT license at your option.