Apache BRPC is an industrial-grade RPC framework for building reliable and high-performance services. brpc-rs enables BRPC clients and servers implemented in the Rust programming language.

brpc-rs is part of the MesaLock Linux Project.

This project is currently a prototype under active development. Many APIs are missing; the provided APIs are not guaranteed to be stable until 1.0.

• Project root
  • src
    • brpc-rs crate, Rust APIs for brpc-rs
  • brpc-build
    • brpc-build crate, build-time code generator
  • brpc-protoc-plugin
    • brpc-protoc-plugin crate, plugin for Google Protobuf compiler
  • brpc-sys
    • brpc-sys crate, FFI bindings to Apache BRPC
  • examples
    • examples

This graph illustrates how the crates work together:

First build and install Apache BRPC. Instructions can be found in getting_started.md.

Alternatively, you may use the prebuilt deb packages of Apache BRPC 0.9.6 for Ubuntu 16.04/18.04. These are NOT official packages.

Make sure these dependencies are already installed:

$ sudo apt-get install libprotobuf-dev libprotoc-dev protobuf-compiler
$ sudo apt-get install libssl-dev libgflags-dev libleveldb-dev

Install brpc-protoc-plugin from crates.io.

$ cargo install brpc-protoc-plugin

Now we are ready to start a brpc-rs project.

Let's create a small crate, echo_service, that includes an echo_client and an echo_server.

$ cargo new echo_service && cd echo_service

In Cargo.toml , add brpc-rs, prost and bytes to the [dependencies] section; add brpc-build to the [build-dependencies] section. For example,

[build-dependencies]
brpc-build = "0.1.0"

[dependencies]
brpc-rs = "0.1.0"
prost = "0.5.0"
bytes = "0.4.12"

Define two binaries: echo_client and echo_server in Cargo.toml

[[bin]]
name = "echo_client"
path = "src/client.rs"

[[bin]]
name = "echo_server"
path = "src/server.rs"

Put a protobuf file echo.proto in src. This file defines EchoRequest, EchoResponse and EchoService.

syntax="proto2";
package example;
message EchoRequest {
      required string message = 1;
};
message EchoResponse {
      required string message = 1;
};
service EchoService {
      rpc echo(EchoRequest) returns (EchoResponse);
};

Add a line build = "build.rs" in the [package] section in Cargo.toml. Then, create a file called build.rs to generate bindings from src/echo.proto.

fn main() {
    brpc_build::compile_protos(&["src/echo.proto"],
                               &["src"]).unwrap();
}

Note the package name in echo.proto is example. So build.rs would generate two files named example.rs and example.brpc.rs.

Next let's implement the echo server. Create src/server.rs as follows:

use brpc_rs::{Server, ServerOptions, ServiceOwnership};

pub mod echo {
    include!(concat!(env!("OUT_DIR"), "/example.rs"));
    include!(concat!(env!("OUT_DIR"), "/example.brpc.rs"));
}

fn main() {
    let mut service = echo::EchoService::new();
    service.set_echo_handler(&mut move |request, mut response| {
        response.message = request.message.clone();
        Ok(())
    });

    let mut server = Server::new();
    let mut options = ServerOptions::new();
    options.set_idle_timeout_ms(1000);
    server
        .add_service(&service, ServiceOwnership::ServerDoesntOwnService)
        .expect("Failed to add service");
    server.start(50000, &options).expect("Failed to start service");
    server.run(); // Run until CTRL-C
}

Because EchoService defines a function called echo() in echo.proto, the brpc-protoc-plugin generates the Rust definition of set_echo_handler() for EchoService. set_echo_handler() accepts a closure which handles EchoRequest sent from clients and returns an EchoResponse with the same message. The remaining lines create a server that listens at 0.0.0.0:50000.

use brpc_rs::{Channel, ChannelOptions};

pub mod echo {
    include!(concat!(env!("OUT_DIR"), "/example.rs"));
    include!(concat!(env!("OUT_DIR"), "/example.brpc.rs"));
}

fn main() {
    let mut options = ChannelOptions::new();
    options.set_timeout_ms(100);
    let addr = "127.0.0.1:50000".parse().expect("Invalid socket address");
    let ch = Channel::with_options(&addr, &options);
    let client = echo::EchoServiceStub::with_channel(&ch);
    let request = echo::EchoRequest {
        message: "hello".to_owned(),
    };
    match client.echo(&request) {
        Ok(r) => println!("Response: {:?}", r),
        Err(e) => eprintln!("Error: {:?}", e),
    }
}

The client first creates a Channel and initializes a service_stub with that channel. The client then calls service_stub.echo() to send a request..

$ cargo run --bin echo_server &
$ cargo run --bin echo_client
Response: EchoResponse { message: "hello" }

• Yiming Jing <[email protected]> @kevinis

brpc-rs is provided under Apache License, Version 2.0. For a copy, see the LICENSE file.