Roaring

Roaring Bitmaps are a compressed bitmap/bitset format/library. Think of it like a Set which can only hold (32-bit or 64-bit) Integers, with much lower memory use and supporting fast set operations.

Install the gem and add to the application's Gemfile by executing:

$ bundle add roaring

require "roaring"

# Bitmap32 can efficiently store a large range of 32-bit integers
bitmap = Roaring::Bitmap32[1, 2, 3, 999]
bitmap << (2**32 - 1)

# Bitmap64 can efficiently store a large range of 64-bit integers
bitmap = Roaring::Bitmap64[1, 2, 3, 999]
bitmap << (2**32 + 1)
bitmap << (2**64 - 1)

# Element access
bitmap.each { }
bitmap.first # => 1
bitmap.min   # => 1
bitmap.max   # => 18446744073709551615
bitmap.last  # => 18446744073709551615
bitmap[3]    # => 999
bitmap.to_a  # => [1, 2, 3, 999, 4294967297, 18446744073709551615]

b1 = Roaring::Bitmap64.new(200...500)
b2 = Roaring::Bitmap64.new(100...1000)

# Support common set operations
(b1 & b2).size # => 300
(b1 ^ b2).size # => 600
(b2 - b1).size # => 600
(b1 - b2).empty? # => true
b1 < b2 # => true
(b2 - b1) == (b1 ^ b2) # => true

# (De)Serialization (also available via Marshal#{dump,load})
dump = bitmap.serialize
loaded = Roaring::Bitmap64.deserialize(dump)
loaded == bitmap # => true

This is a Ruby wrapper around CRoaring

After checking out the repo, run bin/setup to install dependencies. Then, run rake test 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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/jhawthorn/roaring. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

The gem is available as open source under the terms of the Apache License, Version 2.0.

Everyone interacting in the Roaring project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.