EXAMPLE.markdown

A real configuration

Here's a real config from http://brighterplanet.com. Note that WE USE LIBMEMCACHED with Evan Weaver's gem (so does Twitter).

For config/preinitializer.rb

MEMCACHED_SERVERS = [ 'server1:11211', 'server2:11211', 'server3:11211' ]

For config/environment.rb

config.gem 'memcached', :version => '0.17.3'
config.cache_store = :mem_cache_store, MEMCACHED_SERVERS

For config/initializers/cache_money.rb

require 'cache_money'

# Compatibility shim for memcached gem (0.17.3 at time of writing)
class Memcached
  class Rails < ::Memcached
    def get_multi(keys, raw=false)
      hits = get(keys, !raw)
      case hits
      when NilClass
        {}
      when String
        { keys => raw ? hits : Marshal.load(hits) }
      when Array
        hits.map! { |i| Marshal.load(i) } unless raw
        keys.zip(hits).to_hash_without_nils
      when Hash
        hits = hits.inject({}) { |memo, ary| k, v = ary; memo[k] = Marshal.load(v); memo } unless raw
        hits
      end
    end
  end
end

# Compatibility shim so that we can use the same memcached client for both Rails.cache and cache-money
module Cash
  class Local
    def get_multi(*args)
      if args.first.is_a?(Array)          # [1,2,3], true
        @remote_cache.get_multi *args
      else                                # 1, 2, 3
        @remote_cache.get_multi args
      end
    end

    def delete(key, *options)
      @remote_cache.delete(key)
    end
  end
end

$memcache = Memcached::Rails.new MEMCACHED_SERVERS, :timeout => 2, :binary_protocol => true

$local = Cash::Local.new $memcache
$lock = Cash::Lock.new $memcache
$cache = Cash::Transactional.new $local, $lock

# NOTE: replacing the default memcache-client instance. YMMV
Rails.cache.instance_variable_set :@data, $cache
Rails.cache.silence!

class ActiveRecord::Base
  is_cached :repository => $cache
end

# Make cache-money work with namespaced models
ActiveRecord::Base.cache_config.inherit Delayed::Job
# Make cache-money work with ActiveRecord models with self.abstract_class = true
ActiveRecord::Base.cache_config.inherit Emitter

Hope that helps.