# Copyright (c) 2008 Michael Fellinger m.fellinger@gmail.com
# All files in this distribution are subject to the terms of the Ruby license.
require 'memcache'
module Ramaze
# Cache based on the memcache library which utilizes the memcache-daemon to
# store key/value pairs in namespaces.
class MemcachedCache
# Create a new MemcachedCache with host, port and a namespace that defaults
# to 'ramaze'
#
# For your own usage you should use another namespace.
def initialize(host = 'localhost', port = '11211', namespace = Global.runner)
namespace = Digest::SHA1.hexdigest(namespace)[0..16]
@cache = MemCache.new(["#{host}:#{port}"], :namespace => namespace, :multithread => true)
end
# please read the documentation of memcache-client for further methods.
# also, it is highly recommended to install memcache-client_extensions
# for a bit of speedup and more functionality
# Some examples:
#
# [key] #=> get a key
# [key] = value #=> set a key
# delete(key) #=> delete key
# set_many :x => :y, :n => :m #=> set many key/value pairs
# get_hash :x, :y #=> return a hash with key/value pairs
# stats #=> get some statistics about usage
# namespace #=> get the current namespace
# namespace = 'ramaze' #=> set a different namespace ('ramaze' is default)
# flush_all #=> flush the whole cache (deleting all)
# compression #=> see if compression is true/false
# compression = false #=> turn off compression (it's by default true)
def method_missing(*args, &block)
@cache.__send__(*args, &block)
rescue MemCache::MemCacheError => e
Log.error e.to_s
nil
end
# Fetch for multiple keys at once.
def get_multi(*keys)
# MemCache only responds to get_multi if the memcache-client_extensions gem
# is installed, so we check first and resort to another approach if not.
if @cache.respond_to?(:get_multi)
@cache.get_multi(*keys)
else
@cache.get_hash(*keys)
end
end
# same as get_multi, but returns only the values (in order)
def values_at(*keys)
get_multi(*keys).values_at(*keys)
end
# Flush everything, dangerous!
def clear
@cache.flush_all
end
end
end
