1 files changed, 6 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/cache/mem_cache_store.rb b/activesupport/lib/active_support/cache/mem_cache_store.rb
index f9a7fb1440..4d8e1fdd67 100644
--- a/activesupport/lib/active_support/cache/mem_cache_store.rb
+++ b/activesupport/lib/active_support/cache/mem_cache_store.rb
@@ -13,6 +13,7 @@ module ActiveSupport
     #   server goes down, then MemCacheStore will ignore it until it goes back
     #   online.
     # - Time-based expiry support. See #write and the +:expires_in+ option.
+    # - Per-request in memory cache for all communication with the MemCache server(s).
     class MemCacheStore < Store
       module Response # :nodoc:
         STORED      = "STORED\r\n"
@@ -38,6 +39,8 @@ module ActiveSupport
         addresses = ["localhost"] if addresses.empty?
         @addresses = addresses
         @data = MemCache.new(addresses, options)
+
+        extend Strategy::LocalCache
       end
 
       def read(key, options = nil) # :nodoc:
@@ -80,6 +83,7 @@ module ActiveSupport
       def exist?(key, options = nil) # :nodoc:
         # Doesn't call super, cause exist? in memcache is in fact a read
         # But who cares? Reading is very fast anyway
+        # Local cache is checked first, if it doesn't know then memcache itself is read from
         !read(key, options).nil?
       end
 
@@ -94,7 +98,6 @@ module ActiveSupport
 
       def decrement(key, amount = 1) # :nodoc:
         log("decrement", key, amount)
-
         response = @data.decr(key, amount)
         response == Response::NOT_FOUND ? nil : response
       rescue MemCache::MemCacheError
@@ -102,6 +105,8 @@ module ActiveSupport
       end
 
       def delete_matched(matcher, options = nil) # :nodoc:
+        # don't do any local caching at present, just pass
+        # through and let the error happen
         super
         raise "Not supported by Memcache"
       end