experiment with Tokyo Tyrant as an ActiveRecord cache layer

gistfile1.rb

require 'tokyo_tyrant'
$tyrant = TokyoTyrant::Table.new

module Cacheable
  module TyrantTable
    def self.included(base) #:nodoc:
      super
      base.class_eval %q{
        cattr_accessor :cache_records
        @@cache_records = false
      }
      base.extend ClassMethods
    end

    module ClassMethods #:nodoc:
      # Expire cache by args
      def clear_tyrant(key = '')
        $tyrant.delete_keys_with_prefix(self.cache_key(key))
      end

      def find_with_tyrant(n)
        instantiate($tyrant.fetch(cache_key(n)){ find(n).to_tyrant })
      end

      def [](n)
        find_with_tyrant(n)
      end unless method_defined?(:[])
    end

    def to_tyrant
      attributes.dup.merge("type" => self.class.name)
    end

    # Expire cache for a record
    def clear_tyrant
      self.class.clear_tyrant(self.to_param) unless self.new_record?
    end

    # Cache a record by ID
    def store_record(options = {})
      options = { :force => false }.merge(options)
      key = options.delete(:key) || self.cache_key
      $tyrant.fetch(key, options[:force]){ self.to_tyrant } unless self.new_record?
    end

    # Cache all found records, warning!
    def after_find
      self.store_record if self.class.cache_records
      true
    end

    # Reset cache for all records after save, warning!
    def after_save
      super
      self.store_record(:force => true) unless self.class.cache_records
      true
    end
  end
end

class Foo < ActiveRecord::Base
  include Cacheable::TyrantTable
end

# Awesomeness Follows
Foo[1] # Fetch from Tyrant
# => #<Foo id: 1, bar: "baz">

Benchmark.benchmark(' ' * 20 + Benchmark::Tms::CAPTION, 20) do |b|
  # against mysql on localhost
  b.report('find') do
    10000.times do
      Foo.find(3)
    end
  end

  # against tokyo tyrant on localhost
  b.report('find_with_tyrant') do
    10000.times do
      Foo[3]
    end
  end
end

=begin results
                          user     system      total        real
find                  3.300000   0.320000   3.620000 (  4.803466)
find_with_tyrant      1.370000   0.230000   1.600000 (  2.702054)
=end