Crate crossbar 

crossbar

Zero-copy pub/sub over shared memory. URI-addressed. O(1) transfer at any payload size.

Transfers an 8-byte descriptor through a lock-free ring — O(1) regardless of payload. Subscribers read directly from shared memory via SampleGuard — no copy, no serialization, no service discovery layer.

Supported platforms: Linux, macOS, Windows.

Quick Start

use crossbar::*;

// Publisher
let mut pub_ = ShmPublisher::create("prices", PubSubConfig::default()).unwrap();
let topic = pub_.register("/tick/AAPL").unwrap();

let mut loan = pub_.loan(&topic).unwrap();
loan.set_data(b"hello").unwrap();
loan.publish(); // O(1) — writes 8 bytes to ring

Re-exports

pub use protocol::PubSubConfig;

pub use protocol::Region;

pub use wait::WaitStrategy;

Modules

error

Error types for shared-memory pub/sub operations.

protocol

Core protocol types and layout constants for crossbar pub/sub.

wait

Wait strategies for blocking receive operations.

Structs

PinnedGuard

Near-zero-overhead read reference to a pinned block in shared memory.

PinnedLoan

Mutable view into a pinned block in shared memory.

SampleGuard

Safe zero-copy reference to a published sample in shared memory.

ShmChannel

Bidirectional shared-memory channel.

ShmLoan

A mutable view into a pool block in shared memory.

ShmPublisher

O(1) zero-copy publisher over shared memory.

ShmSubscriber

O(1) zero-copy subscriber for pool-backed pub/sub.

Subscription

A subscription to a single topic on a pool-backed pub/sub region.

TopicHandle

Handle returned by super::shm::ShmPublisher::register. Identifies a topic for use with super::shm::ShmPublisher::loan.

TypedSampleGuard

Typed zero-copy reference to a T: Pod value in shared memory.

TypedShmLoan

Typed mutable loan of a T: Pod value in shared memory.

Traits

Pod

Plain-old-data types where every bit pattern is valid.