Allow users to choose the timestamp format in the cache key

This can be done using the class attribute cache_timestamp_format

Conflicts:
	railties/guides/source/configuring.textile

1 files changed, 12 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/integration.rb b/activerecord/lib/active_record/integration.rb
index 7bdc1bd4c6..7f877a6471 100644
--- a/activerecord/lib/active_record/integration.rb
+++ b/activerecord/lib/active_record/integration.rb
@@ -1,5 +1,16 @@
 module ActiveRecord
   module Integration
+    extend ActiveSupport::Concern
+
+    included do
+      ##
+      # :singleton-method:
+      # Indicates the format used to generate the timestamp format in the cache key.
+      # This is +:number+, by default.
+      class_attribute :cache_timestamp_format, :instance_writer => false
+      self.cache_timestamp_format = :nsec
+    end
+
     # Returns a String, which Action Pack uses for constructing an URL to this
     # object. The default implementation returns this record's id as a String,
     # or nil if this record's unsaved.
@@ -37,7 +48,7 @@ module ActiveRecord
       when new_record?
         "#{self.class.model_name.cache_key}/new"
       when timestamp = self[:updated_at]
-        timestamp = timestamp.utc.to_s(:nsec)
+        timestamp = timestamp.utc.to_s(cache_timestamp_format)
         "#{self.class.model_name.cache_key}/#{id}-#{timestamp}"
       else
         "#{self.class.model_name.cache_key}/#{id}"