Brotli

Brotli is a Ruby implementation of the Brotli 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.

Installation

Add this line to your application's Gemfile:

gem 'brotli'

And then execute:

$ bundle

Or install it yourself as:

$ gem install brotli

Usage

Basic Compression/Decompression

require 'brotli'
compressed = Brotli.deflate(string)
decompressed = Brotli.inflate(compressed)

Custom Dictionary Support

Brotli supports using custom dictionaries to improve compression ratio when you have repetitive data patterns:

# Using a dictionary that contains common patterns in your data
dictionary = "common patterns in my data"
data = "This text contains common patterns in my data multiple times"

# Compress with dictionary
compressed = Brotli.deflate(data, dictionary: dictionary)

# Decompress with the same dictionary
decompressed = Brotli.inflate(compressed, dictionary: dictionary)

Compression Options

# Combine dictionary with other compression options
compressed = Brotli.deflate(data,
  dictionary: dictionary,
  quality: 11,        # 0-11, higher = better compression but slower
  mode: :text,        # :generic (default), :text, or :font
  lgwin: 22,          # window size (10-24)
  lgblock: 0          # block size (0 or 16-24)
)

Streaming Compression with Writer

# Basic usage
File.open('output.br', 'wb') do |file|
  writer = Brotli::Writer.new(file)
  writer.write(data)
  writer.close
end

# With dictionary
File.open('output.br', 'wb') do |file|
  writer = Brotli::Writer.new(file, dictionary: dictionary)
  writer.write(data)
  writer.close
end

See test/brotli_test.rb for more examples.

Development

After checking out the repo, run bin/setup to install bundle and Brotli C library dependencies.

Run rake build to build brotli extension for ruby. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/miyucy/brotli.