Module: Cachable

Included in:
Cobregratis::Base
Defined in:
lib/cachable.rb

Overview

Caching is a way to speed up slow ActiveResource queries by keeping the result of a request around to be reused by subsequent requests.

Caching is turned OFF by default.

Usage

require 'cachable'

module CachedResource < ActiveResource::Base
  include ::Cachable
end

Caching stores

All the caching stores from ActiveSupport::Cache are available as backends for caching. See the Rails rdoc for more information on these stores

Configuration examples ('off' is the default):

CachedResource.connection.cache_store = ActiveSupport::Cache.lookup_store :memory_store
CachedResource.connection.cache_store = ActiveSupport::Cache.lookup_store :file_store, "/path/to/cache/directory"
CachedResource.connection.cache_store = ActiveSupport::Cache.lookup_store :drb_store, "druby://localhost:9192"
CachedResource.connection.cache_store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost"
CachedResource.connection.cache_store = MyOwnStore.new("parameter")

If you are using a store that has write options, you can set them

CachedResource.connection.cache_options = { :expires_in => 60.seconds }

Note: To ensure that caching is turned off, set CachedResource.connection.cache_store = nil

FYI: You can use this with any active resource class, not just Cobregratis.

Class Method Summary (collapse)

Class Method Details

+ (Object) included(base) 



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# File 'lib/cachable.rb', line 36

def self.included(base)
  ActiveResource::Connection.class_eval do
    def cache_store
      @cache_store ||= nil
    end

    def cache_store=(store)
      @cache_store = store
    end
    
    def cache_options
      @cache_options ||= {}
    end
    alias :store_options :cache_options
    
    def cache_options=(options)
      @cache_options = options
    end
    alias :store_options= :cache_options=
    
    def is_caching?
      !@cache_store.nil?
    end
    
    def get_with_cache(path, headers = {})
      return get_without_cache(path, headers) unless is_caching?
      cache_store.fetch(cache_key(path), cache_options) {get_without_cache(path, headers)}
    end
    alias_method_chain :get, :cache

    def put_with_cache(path, body = '', headers = {})
      cache_store.delete(cache_key(path)) if is_caching?
      put_without_cache(path, body, headers)
    end
    alias_method_chain :put, :cache
    
    def delete_with_cache(path, headers = {})
      cache_store.delete(cache_key(path)) if is_caching?
      delete_without_cache(path, headers)
    end
    alias_method_chain :delete, :cache
    
    def cache_key(*args)
      args.join(':')
    end
  end
end