memcached.rb

# mostly golden


module Waves
  module Layers
    module Cache

      class Memcached < Waves::Cache
        require 'memcached'
        
        def initialize(args)
          raise ArgumentError, "need :servers to not be nil" if args[:servers].nil?
          args[:opt] = args[:opt].nil? ? {} : args[:opt]
          @memcached = ::Memcached.new(args[:servers], args[:opt])
        end
 
        def add(key,value, ttl = 0, marshal = true)
          @memcached.add(key.to_s,value,ttl,marshal)
        end
 
        def get(key)
          @memcached.get(key.to_s)
        rescue ::Memcached::NotFound # In order to keep the MemcachedCache layer compliant with Waves::Cache...
                                        # ...we need to be able to expect that an absent key raises WavesCacheError::KeyMissing
          raise WavesCacheError::KeyMissing, "#{key} doesn't exist"
        end
 
        def delete(*keys)
          keys.each {|key| @memcached.delete(key.to_s) }
        end
 
        def clear
          @memcached.flush
        end
 
        alias_method :store, :add # Override our natural Waves::Cache :store method with Memcache's :add
        alias_method :fetch, :get # Override our natural Waves::Cache :fetch method with Memcache's :get
 
        def method_missing(*args, &block)
          @memcached.__send__(*args, &block)
        rescue => e
          Waves::Logger.error e.to_s
          nil
        end
 
        # Would this work?? I'm assuming this block gets called the 'moment' the layer is included?
        def self.included(app)
          Waves.cache = Waves::Layers::Cache::Memcached.new( Waves.config.cache )
        end
 
      end
 
    end
  end
end