Acts As Bloom Filter

THIS WILL LOAD EVERY RECORD IN YOUR TABLE AND USE LOTS OF MEMORY !!!

IF YOUR HAVE A LARGE TABLE IT WILL CRASH YOUR SYSTEM !!!

It would not be useful otherwise, but you are trading network and disk usage for memory.

• Very fast way to know if something is MORE THAN LIKELY or ABSOLUTELY NOT in your database once the data is loaded.
• Easy to use
• Can bloomfilter on more than one column / field

I ran into deprecated code trying to get Rails 3 working so it is Rails 4 and up for now.

You can install via

gem install acts_as_bloomfilter

or add this to your Gemfile

gem 'acts_as_bloomfilter' , git:  "https://github.com/lankford/acts_as_bloomfilter"

then in your model add

include ActsAsBloomFilter

acts_as_bloomfilter :myfieldname , :myothername

like so

class MyClass

  include ActsAsBloomFilter

  acts_as_bloomfilter :myfieldname , :myothername

end

The main use of this for me is when I am doing Extract Transform Load operations which I do a lot of.

I would do something like

unless MyClass.myfieldname_bloom.include? new_value

  MyClass.find_or_create_by(myfieldname:new_value)

end

This adds to your existing model based on the field name you are blooming for

MyClass.myfieldname_bloom

MyClass.myfieldname_bloom.insert 'some value'

MyClass.myfieldname_bloom.delete 'some value'

MyClass.myfieldname_bloom.include? 'some value'

MyClass.myfieldname_bloom.stats

Records that are destroyed are automatically removed from the bloomfilter.

Rails does not have a after_delete callback (coming in rails 5 I think) so those are not removed.

You can remove them with a call like this:

 myfieldname_bloom.delete myfieldname

Tatsuya Mori valdzone@gmail.com (Original C implementation)

This work is based on Ilya Grigorik's bloomfilter wrapper called bloomfilter-rb