pbf-rs

The pbf Rust crate provides functionalities to read and write Protocol Buffers (protobuf) messages. This crate is a 0 dependency package that uses no_std and is intended to be used in embedded systems and WASM applications. The crate is designed to be small and efficient, with the cost of some features and flexibility. It is up to the user to create the necessary data structures and implement the ProtoRead and ProtoWrite traits in order to use it effectively.

Usage

Add the following to your Cargo.toml:

[dependencies]
pbf = "0.3"

Examples

use pbf::{ProtoRead, ProtoWrite, Protobuf, Field, Type};

#[derive(Default)]
struct TestMessage {
    a: i32,
    b: String,
}
impl TestMessage {
    fn new(a: i32, b: &str) -> Self {
        TestMessage { a, b: b.to_owned() }
    }
}
impl ProtoWrite for TestMessage {
    fn write(&self, pb: &mut Protobuf) {
        pb.write_varint_field::<u64>(1, self.a as u64);
        pb.write_string_field(2, &self.b);
    }
}
impl ProtoRead for TestMessage {
    fn read(&mut self, tag: u64, pb: &mut Protobuf) {
        println!("tag: {}", tag);
        match tag {
            1 => self.a = pb.read_varint::<i32>(),
            2 => self.b = pb.read_string(),
            _ => panic!("Invalid tag"),
        }
    }
}

let mut pb = Protobuf::new();
let msg = TestMessage::new(1, "hello");
pb.write_message(1, &msg);

let bytes = pb.take();
let mut pb = Protobuf::from_input(RefCell::new(bytes));

// first read in the field for the message
let field = pb.read_field();
assert_eq!(
    field,
    Field {
        tag: 1,
        r#type: Type::Bytes
    }
);

let mut msg = TestMessage::default();
pb.read_message(&mut msg);
assert_eq!(msg.a, 1);
assert_eq!(msg.b, "hello");

Development

Requirements

You need the tool tarpaulin to generate the coverage report. Install it using the following command:

cargo install cargo-tarpaulin

The bacon coverage tool is used to generate the coverage report. To utilize the pycobertura package for a prettier coverage report, install it using the following command:

pip install pycobertura

Running Tests

To run the tests, use the following command:

cargo test
# bacon
bacon test

Generating Coverage Report

To generate the coverage report, use the following command:

cargo tarpaulin
# bacon
bacon coverage # or type `l` inside the tool