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.