commit	db02a6c73af6bd09b7214f7d1ab61e9b13daf6bb	[log] [tgz]
author	Android Build Coastguard Worker <android-build-coastguard-worker@google.com>	Sat Apr 01 07:52:13 2023 +0000
committer	Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>	Sat Apr 01 07:52:13 2023 +0000
tree	b50a997b739f6671b8dc0e6d8d7402b7d61e47b2
parent	68261c0883782e45f349acc792a2021f955d03db [diff]
parent	47c6ba213aab0b9c74bf619b71814abac5527b22 [diff]

tree: b50a997b739f6671b8dc0e6d8d7402b7d61e47b2

README.md

Library to read and write protocol buffers data

Version 2 is stable

Currently developed branch of rust-protobuf is 3. It has the same spirit as version 2, but contains numerous improvements like:

runtime reflection for mutability, not just for access
protobuf text format and JSON parsing (which rely on reflection)
dynamic message support: work with protobuf data without generating code from schema

Stable version of rust-protobuf will be supported until version 3 released.

Tracking issue for version 3.

How to generate rust code

There are several ways to generate rust code from .proto files

Invoke `protoc` programmatically with protoc-rust crate (recommended)

Have a look at readme in protoc-rust crate.

Use pure rust protobuf parser and code generator

Readme should be in protobuf-codegen-pure crate.

Use protoc-gen-rust plugin

Readme is here.

Generated code

Have a look at generated files (for current development version), used internally in rust-protobuf:

descriptor.rs for descriptor.proto (that is part of Google protobuf)

Copy on write

Rust-protobuf can be used with bytes crate.

To enable Bytes you need to:

Enable with-bytes feature in rust-protobuf:

[dependencies]
protobuf = { version = "~2.0", features = ["with-bytes"] }

Enable bytes option

with Customize when codegen is invoked programmatically:

protoc_rust::run(protoc_rust::Args {
    ...
    customize: Customize {
        carllerche_bytes_for_bytes: Some(true),
        carllerche_bytes_for_string: Some(true),
        ..Default::default()
    },
});

or in .proto file:

import "rustproto.proto";

option (rustproto.carllerche_bytes_for_bytes_all) = true;
option (rustproto.carllerche_bytes_for_string_all) = true;

With these options enabled, fields of type bytes or string are generated as Bytes or Chars respectively. When CodedInputStream is constructed from Bytes object, fields of these types get subslices of original Bytes object, instead of being allocated on heap.

Accompanying crates

protoc-rust and protobuf-codegen-pure can be used to rust code from .proto crates.
protobuf-codegen for protoc-gen-rust protoc plugin.
protoc crate can be used to invoke protoc programmatically.
protoc-bin-vendored contains protoc command packed into the crate.