BROTLI DATA COMPRESSION LIBRARY

Brotli is a generic-purpose lossless compression algorithm that compresses data
using a combination of a modern variant of the LZ77 algorithm, Huffman coding
and 2nd order context modeling, with a compression ratio comparable to the best
currently available general-purpose compression methods. It is similar in speed
with deflate but offers more dense compression.

The specification of the Brotli Compressed Data Format is defined in RFC 7932
https://tools.ietf.org/html/rfc7932

Brotli is open-sourced under the MIT License, see the LICENSE file.

Brotli mailing list:
https://groups.google.com/forum/#!forum/brotli

<p align="center"><img src="https://brotli.org/brotli.svg" alt="Brotli" width="64"></p>

# SECURITY NOTE

Please consider updating brotli to version 1.0.9 (latest).

Version 1.0.9 contains a fix to "integer overflow" problem. This happens when "one-shot" decoding API is used (or input chunk for streaming API is not limited), input size (chunk size) is larger than 2GiB, and input contains uncompressed blocks. After the overflow happens, `memcpy` is invoked with a gigantic `num` value, that will likely cause the crash.

### Introduction

Brotli is a generic-purpose lossless compression algorithm that compresses data
using a combination of a modern variant of the LZ77 algorithm, Huffman coding
and 2nd order context modeling, with a compression ratio comparable to the best
currently available general-purpose compression methods. It is similar in speed
with deflate but offers more dense compression.

The specification of the Brotli Compressed Data Format is defined in [RFC 7932](https://tools.ietf.org/html/rfc7932).

Brotli is open-sourced under the MIT License, see the LICENSE file.

Brotli mailing list:
https://groups.google.com/forum/#!forum/brotli

[![TravisCI Build Status](https://travis-ci.org/google/brotli.svg?branch=master)](https://travis-ci.org/google/brotli)
[![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/google/brotli?branch=master&svg=true)](https://ci.appveyor.com/project/szabadka/brotli)
[![Fuzzing Status](https://oss-fuzz-build-logs.storage.googleapis.com/badges/brotli.svg)](https://oss-fuzz-build-logs.storage.googleapis.com/index.html#brotli)

### Build instructions

#### Vcpkg

You can download and install brotli using the [vcpkg](https://github.com/Microsoft/vcpkg/) dependency manager:

    git clone https://github.com/Microsoft/vcpkg.git
    cd vcpkg
    ./bootstrap-vcpkg.sh
    ./vcpkg integrate install
    vcpkg install brotli

The brotli port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please [create an issue or pull request](https://github.com/Microsoft/vcpkg) on the vcpkg repository.

#### Autotools-style CMake

[configure-cmake](https://github.com/nemequ/configure-cmake) is an
autotools-style configure script for CMake-based projects (not supported on Windows).

The basic commands to build, test and install brotli are:

    $ mkdir out && cd out
    $ ../configure-cmake
    $ make
    $ make test
    $ make install

By default, debug binaries are built. To generate "release" `Makefile` specify `--disable-debug` option to `configure-cmake`.

#### Bazel

See [Bazel](http://www.bazel.build/)

#### CMake

The basic commands to build and install brotli are:

    $ mkdir out && cd out
    $ cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=./installed ..
    $ cmake --build . --config Release --target install

You can use other [CMake](https://cmake.org/) configuration.

#### Premake5

See [Premake5](https://premake.github.io/)

#### Python

To install the latest release of the Python module, run the following:

    $ pip install brotli

To install the tip-of-the-tree version, run:

    $ pip install --upgrade git+https://github.com/google/brotli

See the [Python readme](python/README.md) for more details on installing
from source, development, and testing.

### Benchmarks
* [Squash Compression Benchmark](https://quixdb.github.io/squash-benchmark/) / [Unstable Squash Compression Benchmark](https://quixdb.github.io/squash-benchmark/unstable/)
* [Large Text Compression Benchmark](http://mattmahoney.net/dc/text.html)
* [Lzturbo Benchmark](https://sites.google.com/site/powturbo/home/benchmark)

### Related projects
> **Disclaimer:** Brotli authors take no responsibility for the third party projects mentioned in this section.

Independent [decoder](https://github.com/madler/brotli) implementation by Mark Adler, based entirely on format specification.

JavaScript port of brotli [decoder](https://github.com/devongovett/brotli.js). Could be used directly via `npm install brotli`

Hand ported [decoder / encoder](https://github.com/dominikhlbg/BrotliHaxe) in haxe by Dominik Homberger. Output source code: JavaScript, PHP, Python, Java and C#

7Zip [plugin](https://github.com/mcmilk/7-Zip-Zstd)

Dart [native bindings](https://github.com/thosakwe/brotli)