Variable Len Reader

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Description

A Rust crate to read variable length data. (VarInt)

Read and write compressed data. Of each such byte, only 7 bits will be used to describe the actual value since its most significant bit indicates whether the next byte is part of the same int. Micro-optimization for int values that are expected to have values below 128.

Usage

Add this to your Cargo.toml:

[dependencies]
variable-len-reader = "*"

Example

Directly use in tcp stream:

use std::net::{TcpListener, TcpStream};
use variable_len_reader::variable_len::{read_variable_u32, write_variable_u32};

fn main() {
    let addr = "localhost:25564";
    let server = TcpListener::bind(addr).unwrap();
    let mut client = TcpStream::connect(addr).unwrap();
    let mut server = server.incoming().next().unwrap().unwrap();

    // Write
    write_variable_u32(&mut client, 1234).unwrap();

    // Read
    let message = read_variable_u32(&mut server).unwrap();
    assert_eq!(1234, message);
}

Use with bytes crate:

use bytes::{Buf, BufMut, BytesMut};
use variable_len_reader::variable_len::{read_variable_u32, write_variable_u32};

fn main() {
    let mut writer = BytesMut::new().writer();

    // Write
    write_variable_u32(&mut writer, 4321).unwrap();

    let bytes = writer.into_inner();
    let mut reader = bytes.reader();

    // Read
    let message = read_variable_u32(&mut reader).unwrap();
    assert_eq!(4321, message);
}