rust-ipfs/vendor/miniz_oxide

miniz_oxide

A fully safe, pure rust replacement for the miniz DEFLATE/zlib encoder/decoder. The main intention of this crate is to be used as a back-end for the flate2, but it can also be used on its own. Using flate2 with the rust_backend feature provides an easy to use streaming API for miniz_oxide.

The library is fully no_std. By default, the with-alloc feature is enabled, which requires the use of the alloc and collection crates as it allocates memory.

The std feature additionally turns on things only available if no_std is not used. Currently this only means implementing Error for the DecompressError error struct returned by the simple decompression functions if enabled together with with-alloc.

Using the library with default-features = false removes the dependency on alloc and collection crates, making it suitable for systems without an allocator. Running without allocation reduces crate functionality:

• The deflate module is removed completely
• Some inflate functions which return a Vec are removed

miniz_oxide 0.5.x and 0.6.x Requires at least rust 1.40.0 0.3.x requires at least rust 0.36.0.

miniz_oxide features no use of unsafe code.

miniz_oxide can optionally be made to use a simd-accelerated version of adler32 via the simd-adler32 crate by enabling the 'simd' feature. This is not enabled by default as due to the use of simd intrinsics, the simd-adler32 has to use unsafe. The default setup uses the adler crate which features no unsafe code.

Usage

Simple compression/decompression:

use miniz_oxide::deflate::compress_to_vec;
use miniz_oxide::inflate::decompress_to_vec;

fn roundtrip(data: &[u8]) {
    // Compress the input
    let compressed = compress_to_vec(data, 6);
    // Decompress the compressed input and limit max output size to avoid going out of memory on large/malformed input.
    let decompressed = decompress_to_vec_with_limit(compressed.as_slice(), 60000).expect("Failed to decompress!");
    // Check roundtrip succeeded
    assert_eq!(data, decompressed);
}

fn main() {
    roundtrip("Hello, world!".as_bytes());
}

These simple functions will do everything in one go and are thus not recommended for use cases outside of prototyping/testing as real world data can have any size and thus result in very large memory allocations for the output Vector. Consider using miniz_oxide via flate2 which makes it easy to do streaming (de)compression or the low-level streaming functions instead.