A Brotli implementation in pure and safe Rust
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README.md

Brotli-rs - Brotli decompression in pure, safe Rust

Build Status Works on stable Works on beta Works on nightly

Documentation

Compression provides a <Read>-struct to wrap a Brotli-compressed stream. A consumer is thus able to read a compressed stream with usual convenience.

Changelog

###v0.3.22 -> v0.3.23

Bug with literal buffer not being populated when processing uncompressed metablock, bug where a valid stream could be rejected too early as oversized, if the last bytes happened to be shortened by an OMIT-type transformation after the early check, reported and fixed by Daniel.

###v0.3.21 -> v0.3.22

Bug with metablock structure not getting fully reset when encountering a new metablock in the brotli stream, reported and fixed by Daniel.

###v0.3.20 -> v0.3.21

Bug with multiple metablocks, reported and fixed by Daniel.

###v0.3.19 -> v0.3.20

Worked around feature gate issue in nightly. (Thanks, Corey!)

###v0.3.18 -> v0.3.19

Removed 64k big Pseudo-Code lookup table, because creating this trivial table probably took more time than making the calculcation on the fly. (Bench tests seem to suggest a 1% time savings without the lookup table)

###v0.3.17 -> v0.3.18

Fixed case where a simple prefix code could have duplicate symbols.

###v0.3.16 -> v0.3.17

Fixed case where a complex prefix code could have an incorrect checksum on its runlength code.

###v0.3.15 -> v0.3.16

  • Fixed incorrect calculation of alphabet size for distance code.
  • Fixed evaluation where streams with excessive insert/copy lengths could be rejected early.

###v0.3.14 -> v0.3.15

Fixed injection of invalid symbols in simple prefix code.

###v0.3.13 -> v0.3.14

Fixed invalid block-type in switch command. (Thanks, Corey!).

###v0.3.12 -> v0.3.13

Fixed uncaught non-positive distances. (Thanks, Corey!).

###v0.3.11 -> v0.3.12

Fixed uncaught zero-byte in word transformation. (Thanks, Corey!).

###v0.3.10 -> v0.3.11

Fixed possible arithmetic overflow in word transformation. (Thanks, Corey!).

###v0.3.9 -> v0.3.10

Fixed incorrect type for runlength code. (Thanks, Corey!).

###v0.3.8 -> v0.3.9

Fixed incorrect array index bound check in tree lookup. (Thanks, Corey!).

###v0.3.7 -> v0.3.8

Fixed some value range checks on block types and ntree*. (Thanks, Corey!).

###v0.3.6 -> v0.3.7

Went over "unreachable!()" statements, analyzed, and handled error condition properly, if they were reachable through invalid data.

###v0.3.5 -> v0.3.6

Fixed a case where an invalid prefix code with all-zero codelengths could create an index-out-of-bounds panic. (Thanks, Corey!).

###v0.3.4 -> v0.3.5

Fixed a case where an invalid insert-and-copy-length-code would produce a panic. (Thanks, Corey!).

###v0.3.1 -> v0.3.4

Fair amount of internal small improvements, improving code quality. Fixed a couple of cases where invalid streams would lead to panics and/or infinite loops (Thanks, Corey!).

###v0.3.0 -> v0.3.1

This is only a minor version bump, with no breakage in usage, but it's exciting nonetheless!

In Brotli, a lot of work is done with and by prefix codes. Through a change in the internal representation of prefix codes, it was possible to speed the reference benchmark time by a factor of ~7. The benchmark decompresses the contents of the file data/monkey.compressed.

  • With linked-list-based, recursive tree implementation:
    test bench_monkey ... bench: 866,888 ns/iter (+/- 58,119)

  • With array-based, iterative tree implementation, before max-depth constraint:
    test bench_monkey ... bench: 704,282 ns/iter (+/- 220,068)

  • With array-based, iterative tree implementation, with max-depth constraint:
    test bench_monkey ... bench: 120,745 ns/iter (+/- 16,627)

###v0.2.0 -> v0.3.0

  • renamed crate compression -> brotli
  • restructured modules to avoid redundant paths like brotli::brotli::Decompressor (now it's just brotli::Decompressor)

###v0.1.0 -> v0.2.0

  • Decompressor::new() now accepts a Read, as opposed to a BitReader.