A bloom-filter (after Burton H. Bloom) is a method of superimposed coding on primary keys. The purpose is to provide a means of set membership queries utilizing minimal space — with the tradeoff of an adjustable rate of false positives.

See this article for a little background.

Latest changes

• Tries the BitSet (C extension) before falling back on its own SimpleVector (support for BitVector removed as it had no real performance advantage over BitSet, and it had leaked).
• BloomFilters are marshal-able, so you only need create your large filter once and then store or transmit it.

Downloads:

• download
• docs

Or grab it from my darcs repository:

  darcs get http://repos.siaris.net/ruby/BloomFilter