Crate ai_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

Structs

Compressor

Compressor that produces zlib or raw deflate compressed streams.

Decompressor

Decompressor for arbitrary zlib streams.

StoredOnlyCompressor

Compressor that only writes stored (uncompressed) deflate blocks inside a zlib stream.

UltraFastCompressor

Compressor that produces fdeflate compressed streams.

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.

compress_to_vec_rle

Compresses the given data using only RLE matches.

compress_to_vec_ultra_fast

Compresses the given data using the ultra fast compression method.

compress_to_vec_with_level

Compresses the given data with a specific compression level.

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.