1 files changed, 16 insertions, 3 deletions
diff --git a/activesupport/lib/active_support/cache.rb b/activesupport/lib/active_support/cache.rb
index feb6b1f2cf..3c422e0252 100644
--- a/activesupport/lib/active_support/cache.rb
+++ b/activesupport/lib/active_support/cache.rb
@@ -2,7 +2,12 @@ require 'benchmark'
 require 'active_support/core_ext/benchmark'
 require 'active_support/core_ext/exception'
 require 'active_support/core_ext/class/attribute_accessors'
-require 'active_support/core_ext' # FIXME: pulling in all to_param extensions
+
+%w(hash nil string time date date_time array big_decimal range object boolean).each do |library|
+  require "active_support/core_ext/#{library}/conversions"
+end
+
+# require 'active_support/core_ext' # FIXME: pulling in all to_param extensions
 
 module ActiveSupport
   # See ActiveSupport::Cache::Store for documentation.
@@ -129,8 +134,8 @@ module ActiveSupport
       #
       # For example, MemCacheStore's #write method supports the +:expires_in+
       # option, which tells the memcached server to automatically expire the
-      # cache item after a certain period. We can use this option with #fetch
-      # too:
+      # cache item after a certain period. This options is also supported by
+      # FileStore's #read method. We can use this option with #fetch too:
       #
       #   cache = ActiveSupport::Cache::MemCacheStore.new
       #   cache.fetch("foo", :force => true, :expires_in => 5.seconds) do
@@ -169,6 +174,10 @@ module ActiveSupport
       # You may also specify additional options via the +options+ argument.
       # The specific cache store implementation will decide what to do with
       # +options+.
+      #
+      # For example, FileStore supports the +:expires_in+ option, which
+      # makes the method return nil for cache items older than the specified
+      # period.
       def read(key, options = nil)
         log("read", key, options)
       end
@@ -223,6 +232,10 @@ module ActiveSupport
       end
 
       private
+        def expires_in(options)
+          (options && options[:expires_in]) || 0
+        end
+
         def log(operation, key, options)
           logger.debug("Cache #{operation}: #{key}#{options ? " (#{options.inspect})" : ""}") if logger && !@silence && !@logger_off
         end