Crate fdeflate

A fast deflate implementation.

This crate contains an optimized implementation of the deflate algorithm tuned to compress PNG images. It is compatible with standard zlib, but make a bunch of simplifying assumptions that drastically improve encoding performance:

• Exactly one block per deflate stream.
• No distance codes except for run length encoding of zeros.
• A single fixed huffman tree trained on a large corpus of PNG images.
• All huffman codes are 12 bits or less.

It also contains a fast decompressor that supports arbitrary zlib streams but does especially well on streams that meet the above assumptions.

Inspiration

The algorithms in this crate take inspiration from multiple sources:

• fpnge
• zune-inflate
• RealTime Data Compression blog

Modules

compress 🔒

decompress 🔒

huffman 🔒

tables 🔒

Structs

Compressor

Compressor that produces fdeflate compressed streams.

Decompressor

Decompressor for arbitrary zlib streams.

StoredOnlyCompressor

Compressor that only writes the stored blocks.

Enums

BoundedDecompressionError

An error encountered while decompressing a deflate stream given a bounded maximum output.

DecompressionError

An error encountered while decompressing a deflate stream.

Functions

compress_to_vec

Compresses the given data.

compute_codes 🔒

decompress_to_vec

Decompress the given data.

decompress_to_vec_bounded

Decompress the given data, returning an error if the output is larger than maxlen bytes.