Bithex

Store hex strings as PostgreSQL bit strings to reduce column size 2x.

Installation

Add this line to your application's Gemfile:

gem 'bithex'

And then execute:

$ bundle

Or install it yourself as:

$ gem install bithex

Create column

create_table :uploads do |t|
  t.column :digest, "bit(160)" # For SHA1 limit is 160, for MD5 limit is 128
end

Define bithex attributes

class Upload < ActiveRecord::Base
  bithex :digest

  # if you have multiple attributes to store as bit string
  # bithex :foo, :bar, :baz
end

Treat you bithex attribute as usual string, but remember: string length is hardcoded by limit of bit column (40 for SHA1, 32 for MD5)

upload = Upload.new
upload.digest = Digest::SHA1.hexdigest('foo bar baz') # c7567e8b39e2428e38bf9c9226ac68de4c67dc39
upload.save

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

The gem is available as open source under the terms of the MIT License.