rocketmq-protocol

RocketMQ wire contracts: request/response codes, remoting command frames, custom headers, protocol bodies, compression, and trace encoding. This crate does not open sockets or own a Tokio runtime.

API and ownership

• RequestCode, RemotingSysResponseCode, and the code module define request and response identity.
• RemotingCommand, EncodedFrame, and EncodedFrameHead represent commands and encoded frame parts.
• CommandCustomHeader, HeaderCodec, HeaderMap, and FromMap support typed header encoding and decoding. Derive macros are provided by rocketmq-macros.
• RpcRequestHeader and TopicRequestHeader provide shared RPC header fields.
• ProtocolContractViolation reports invalid protocol contracts; operational failures retain canonical rocketmq-error identity.

Business command construction uses RemotingCommandFactory with immutable RemotingCommandDefaults. An explicit factory can carry independent version/serialization settings without rereading process configuration. The compatibility application-default path is initialized by the application owner. JSON and RocketMQ binary serialization are distinct wire formats; changing a Rust field or enum must preserve its intended wire representation.

The hidden __request_header_codec module is support for generated code, not a general integration entry point. Networking, frame limits, connection admission, and request deadlines belong to rocketmq-transport.

Features

Default features are empty. simd enables accelerated decoding paths through simd-json; callers still use the same protocol APIs. There is no server binary in this package.

Validation

Run from the root workspace:

cargo test -p rocketmq-protocol --test remoting_command_factory --test remoting_wire_golden
cargo test -p rocketmq-protocol --test message_codec_compatibility
cargo bench -p rocketmq-protocol --bench request_header_codec

The tests directory also contains Java compatibility fixtures and compile-fail coverage for header derives. Select the relevant codec and feature combination for a change.

Licensed under Apache-2.0.