vbe-rs – A Variable Byte Encoding Rust Library

This Rust library provides functionality for Variable Byte Encoding (VBE), a form of lossless data compression that is commonly used for encoding integers in a way that results in smaller output size for smaller numbers. This is particularly useful in applications such as databases and indexes, where many numbers may be small and memory efficiency is important.

Usage

To use this library in your Rust project, add the following to your Cargo.toml file:

[dependencies]
vbe = { git = "https://github.com/bazzilic/vbe-rs", tag = "v0.1.1" }

Then, import the vbe module in your Rust code:

use vbe::{encode, decode};

The encode function takes a reference to an unsigned integer and returns a Vec<u8> containing the VBE representation of the number:

let number: u128 = 123456789;
let encoded = vbe::encode(&number);

The decode function takes an iterator over u8 (such as a Vec<u8> or a slice) and returns a Result<u128, String>. If the input is a valid VBE representation of a number, decode will return Ok(number). If the input is not valid (for example, if it ends in the middle of a number), decode will return an Err with an error message:

let encoded: Vec<u8> = vec![...]; // some VBE-encoded bytes
match vbe::decode(encoded.into_iter()) {
    Ok(number) => println!("The number is {}", number),
    Err(err) => println!("Failed to decode: {}", err),
}

Note that decode mutates and advances the iterator. This way, if you have multiple VBE-encoded numbers in a byte array, you can continue calling ``decode` using the same iterator to decode the numbers one by one.

Testing

The library comes with unit tests for the encode and decode functions. You can run these tests using the command cargo test.

VBE format

Contributing

Contributions to this project are welcome. Please feel free to submit a pull request or open an issue on the project's GitHub page.

License

This project is licensed under the MIT license. See the LICENSE file for more details.