vendor/rails/actionpack/lib/action_controller/caching.rb

   1 require 'fileutils'
   2 require 'uri'
   3 require 'set'
   4
   5 require 'action_controller/caching/pages'
   6 require 'action_controller/caching/actions'
   7 require 'action_controller/caching/sql_cache'
   8 require 'action_controller/caching/sweeping'
   9 require 'action_controller/caching/fragments'
  10
  11
  12 module ActionController #:nodoc:
  13   # Caching is a cheap way of speeding up slow applications by keeping the result of calculations, renderings, and database calls
  14   # around for subsequent requests. Action Controller affords you three approaches in varying levels of granularity: Page, Action, Fragment.
  15   #
  16   # You can read more about each approach and the sweeping assistance by clicking the modules below.
  17   #
  18   # Note: To turn off all caching and sweeping, set Base.perform_caching = false.
  19   #
  20   #
  21   # == Caching stores
  22   #
  23   # All the caching stores from ActiveSupport::Cache is available to be used as backends for Action Controller caching. This setting only
  24   # affects action and fragment caching as page caching is always written to disk.
  25   #
  26   # Configuration examples (MemoryStore is the default):
  27   #
  28   #   ActionController::Base.cache_store = :memory_store
  29   #   ActionController::Base.cache_store = :file_store, "/path/to/cache/directory"
  30   #   ActionController::Base.cache_store = :drb_store, "druby://localhost:9192"
  31   #   ActionController::Base.cache_store = :mem_cache_store, "localhost"
  32   #   ActionController::Base.cache_store = MyOwnStore.new("parameter")
  33   module Caching
  34     def self.included(base) #:nodoc:
  35       base.class_eval do
  36         @@cache_store = nil
  37         cattr_reader :cache_store
  38
  39         # Defines the storage option for cached fragments
  40         def self.cache_store=(store_option)
  41           @@cache_store = ActiveSupport::Cache.lookup_store(store_option)
  42         end
  43
  44         include Pages, Actions, Fragments
  45         include Sweeping, SqlCache if defined?(ActiveRecord)
  46
  47         @@perform_caching = true
  48         cattr_accessor :perform_caching
  49
  50         def self.cache_configured?
  51           perform_caching && cache_store
  52         end
  53       end
  54     end
  55
  56     protected
  57       # Convenience accessor
  58       def cache(key, options = {}, &block)
  59         if cache_configured?
  60           cache_store.fetch(ActiveSupport::Cache.expand_cache_key(key, :controller), options, &block)
  61         else
  62           yield
  63         end
  64       end
  65
  66
  67     private
  68       def cache_configured?
  69         self.class.cache_configured?
  70       end
  71   end
  72 end