photon_ring/
lib.rs

1// Copyright 2026 Photon Ring Contributors
2// SPDX-License-Identifier: MIT OR Apache-2.0
3
4//! # Photon Ring
5//!
6//! Ultra-low-latency SPMC pub/sub using seqlock-stamped ring buffers.
7//!
8//! Fully `no_std` compatible (requires `alloc`). Every type — including the
9//! named-topic [`Photon`] bus — works without the standard library.
10//!
11//! ## Key design
12//!
13//! - **Seqlock per slot** — stamp and payload share a cache line; readers never
14//!   take a lock, writers never allocate.
15//! - **`T: Copy`** — enables safe `memcpy` reads; torn reads are detected and
16//!   retried (no `Drop` / double-free concerns).
17//! - **Per-consumer cursor** — zero contention between subscribers.
18//! - **Single-producer** — no write-side synchronisation; the seqlock invariant
19//!   is upheld by `&mut self` on [`Publisher::publish`].
20//!
21//! ## Quick start
22//!
23//! ```
24//! // Low-level SPMC channel
25//! let (mut pub_, subs) = photon_ring::channel::<u64>(64);
26//! let mut sub = subs.subscribe();
27//! pub_.publish(42);
28//! assert_eq!(sub.try_recv(), Ok(42));
29//!
30//! // Named-topic bus
31//! let bus = photon_ring::Photon::<u64>::new(64);
32//! let mut p = bus.publisher("topic-a");
33//! let mut s = bus.subscribe("topic-a");
34//! p.publish(7);
35//! assert_eq!(s.try_recv(), Ok(7));
36//! ```
37
38#![no_std]
39
40extern crate alloc;
41
42#[cfg(feature = "affinity")]
43pub mod affinity;
44mod bus;
45pub mod channel;
46#[cfg(all(target_os = "linux", feature = "hugepages"))]
47pub mod mem;
48pub(crate) mod ring;
49pub(crate) mod slot;
50pub mod wait;
51
52pub use bus::Photon;
53pub use channel::{
54    channel, channel_bounded, PublishError, Publisher, Subscribable, Subscriber, SubscriberGroup,
55    TryRecvError,
56};
57pub use wait::WaitStrategy;
photon_ring/lib.rs

photon_ring/
lib.rs
