lzfse-rs

https://img.shields.io/crates/v/lzfse

Rust bindings for the LZFSE reference implementation at https://github.com/lzfse/lzfse.

Documentation

# Cargo.toml
[dependencies]
lzfse = "0.2.0"

lib.rs:

Rust bindings for the LZFSE reference implementation

https://github.com/lzfse/lzfse

Example

use lzfse::{decode_buffer, encode_buffer};

let input: &[u8] = &[0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE];

// compression
// in the worst case lzfse will fallback to return the input uncompressed
// and add a magic header to indicate this. that requires 12 bytes (see lzfse_encode.c)
let max_outlen = input.len() + 12;
let mut compressed = vec![0; max_outlen];

let bytes_out = encode_buffer(&input[..], &mut compressed[..]).unwrap();
assert!(bytes_out < input.len());

// decompression
// need to allocate 1 byte more since lzfse returns input.len() if the buffer is too small
let mut uncompressed = vec![0; input.len() + 1];
let bytes_in = decode_buffer(&compressed[0..bytes_out], &mut uncompressed[..]).unwrap();

assert_eq!(bytes_in, input.len());
assert_eq!(input[..], uncompressed[..bytes_in]);

Scratch Buffer Example

The encode_buffer_scratch and decode_buffer_scratch functions allow for encoding and decoding using a scratch buffer to avoid allocations by the underlying library. This makes it possible to use the Rust crate with no_std and a custom allocator.

use lzfse::{encode_buffer_scratch, decode_buffer_scratch, Scratch};

let input: &[u8] = &[0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE,
                     0xF, 0xE, 0xE, 0xD, 0xF, 0xA, 0xC, 0xE];

let mut compressed = vec![0; input.len() + 12];
let mut scratch = Scratch::new();

let bytes_out = encode_buffer_scratch(&input, &mut compressed, &mut scratch).unwrap();
assert!(bytes_out < input.len());

let mut uncompressed = vec![0; input.len() + 1];
let bytes_in = decode_buffer_scratch(&compressed[0..bytes_out], &mut uncompressed, &mut scratch).unwrap();

assert_eq!(bytes_in, input.len());
assert_eq!(input[..], uncompressed[..bytes_in]);