Replace deprecated memcache-client gem with dalli in ActiveSupport::Cache::MemCacheStore

memcache-client was deprecated in favour of dalli in 2010.

Author: guilleiguaran

Gemfile

@@ -40,7 +40,7 @@ group :doc do
 end
 
 # AS
-gem 'memcache-client', '>= 1.8.5'
+gem 'dalli'
 
 # Add your own local bundler stuff
 local_gemfile = File.dirname(__FILE__) + "/.Gemfile"

activesupport/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Rails 4.0.0 (unreleased) ##
 
+*   Replace deprecated `memcache-client` gem with `dalli` in ActiveSupport::Cache::MemCacheStore
+
+    *Guillermo Iguaran*
+
 *   Add default values to all `ActiveSupport::NumberHelper` methods, to avoid
     errors with empty locales or missing values.
 

activesupport/lib/active_support/cache/mem_cache_store.rb

@@ -1,7 +1,7 @@
 begin
-  require 'memcache'
+  require 'dalli'
 rescue LoadError => e
-  $stderr.puts "You don't have memcache-client installed in your application. Please add it to your Gemfile and run bundle install"
+  $stderr.puts "You don't have dalli installed in your application. Please add it to your Gemfile and run bundle install"
   raise e
 end
 
@@ -22,21 +22,13 @@ module Cache
     # MemCacheStore implements the Strategy::LocalCache strategy which implements
     # an in-memory cache inside of a block.
     class MemCacheStore < Store
-      module Response # :nodoc:
-        STORED      = "STORED\r\n"
-        NOT_STORED  = "NOT_STORED\r\n"
-        EXISTS      = "EXISTS\r\n"
-        NOT_FOUND   = "NOT_FOUND\r\n"
-        DELETED     = "DELETED\r\n"
-      end
-
       ESCAPE_KEY_CHARS = /[\x00-\x20%\x7F-\xFF]/n
 
       def self.build_mem_cache(*addresses)
         addresses = addresses.flatten
         options = addresses.extract_options!
         addresses = ["localhost:11211"] if addresses.empty?
-        MemCache.new(addresses, options)
+        Dalli::Client.new(addresses, options)
       end
 
       # Creates a new MemCacheStore object, with the given memcached server
@@ -90,11 +82,11 @@ def read_multi(*names)
       # to zero.
       def increment(name, amount = 1, options = nil) # :nodoc:
         options = merged_options(options)
-        response = instrument(:increment, name, :amount => amount) do
+        instrument(:increment, name, :amount => amount) do
           @data.incr(escape_key(namespaced_key(name, options)), amount)
         end
-        response == Response::NOT_FOUND ? nil : response.to_i
-      rescue MemCache::MemCacheError
+      rescue Dalli::DalliError
+        logger.error("DalliError (#{e}): #{e.message}") if logger
         nil
       end
 
@@ -104,18 +96,21 @@ def increment(name, amount = 1, options = nil) # :nodoc:
       # to zero.
       def decrement(name, amount = 1, options = nil) # :nodoc:
         options = merged_options(options)
-        response = instrument(:decrement, name, :amount => amount) do
+        instrument(:decrement, name, :amount => amount) do
           @data.decr(escape_key(namespaced_key(name, options)), amount)
         end
-        response == Response::NOT_FOUND ? nil : response.to_i
-      rescue MemCache::MemCacheError
+      rescue Dalli::DalliError
+        logger.error("DalliError (#{e}): #{e.message}") if logger
         nil
       end
 
       # Clear the entire cache on all memcached servers. This method should
       # be used with care when shared cache is being used.
       def clear(options = nil)
         @data.flush_all
+      rescue Dalli::DalliError => e
+        logger.error("DalliError (#{e}): #{e.message}") if logger
+        nil
       end
 
       # Get the statistics from the memcached servers.
@@ -126,9 +121,9 @@ def stats
       protected
         # Read an entry from the cache.
         def read_entry(key, options) # :nodoc:
-          deserialize_entry(@data.get(escape_key(key), true))
-        rescue MemCache::MemCacheError => e
-          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          deserialize_entry(@data.get(escape_key(key), options))
+        rescue Dalli::DalliError => e
+          logger.error("DalliError (#{e}): #{e.message}") if logger
           nil
         end
 
@@ -137,23 +132,17 @@ def write_entry(key, entry, options) # :nodoc:
           method = options && options[:unless_exist] ? :add : :set
           value = options[:raw] ? entry.value.to_s : entry
           expires_in = options[:expires_in].to_i
-          if expires_in > 0 && !options[:raw]
-            # Set the memcache expire a few minutes in the future to support race condition ttls on read
-            expires_in += 5.minutes
-          end
-          response = @data.send(method, escape_key(key), value, expires_in, options[:raw])
-          response == Response::STORED
-        rescue MemCache::MemCacheError => e
-          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          @data.send(method, escape_key(key), value, expires_in, options)
+        rescue Dalli::DalliError => e
+          logger.error("DalliError (#{e}): #{e.message}") if logger
           false
         end
 
         # Delete an entry from the cache.
         def delete_entry(key, options) # :nodoc:
-          response = @data.delete(escape_key(key))
-          response == Response::DELETED
-        rescue MemCache::MemCacheError => e
-          logger.error("MemCacheError (#{e}): #{e.message}") if logger
+          @data.delete(escape_key(key))
+        rescue Dalli::DalliError => e
+          logger.error("DalliError (#{e}): #{e.message}") if logger
           false
         end
 

activesupport/test/abstract_unit.rb

@@ -22,11 +22,11 @@
 require 'active_support'
 
 def uses_memcached(test_name)
-  require 'memcache'
+  require 'dalli'
   begin
-    MemCache.new('localhost:11211').stats
+    Dalli::Client.new('localhost:11211').stats
     yield
-  rescue MemCache::MemCacheError
+  rescue Dalli::DalliError
     $stderr.puts "Skipping #{test_name} tests. Start memcached and try again."
   end
 end

activesupport/test/caching_test.rb

@@ -83,34 +83,34 @@ def test_file_fragment_cache_store
   end
 
   def test_mem_cache_fragment_cache_store
-    MemCache.expects(:new).with(%w[localhost], {})
+    Dalli::Client.expects(:new).with(%w[localhost], {})
     store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost"
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
   end
 
   def test_mem_cache_fragment_cache_store_with_given_mem_cache
-    mem_cache = MemCache.new
-    MemCache.expects(:new).never
+    mem_cache = Dalli::Client.new
+    Dalli::Client.expects(:new).never
     store = ActiveSupport::Cache.lookup_store :mem_cache_store, mem_cache
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
   end
 
   def test_mem_cache_fragment_cache_store_with_given_mem_cache_like_object
-    MemCache.expects(:new).never
+    Dalli::Client.expects(:new).never
     memcache = Object.new
     def memcache.get() true end
     store = ActiveSupport::Cache.lookup_store :mem_cache_store, memcache
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
   end
 
   def test_mem_cache_fragment_cache_store_with_multiple_servers
-    MemCache.expects(:new).with(%w[localhost 192.168.1.1], {})
+    Dalli::Client.expects(:new).with(%w[localhost 192.168.1.1], {})
     store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", '192.168.1.1'
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
   end
 
   def test_mem_cache_fragment_cache_store_with_options
-    MemCache.expects(:new).with(%w[localhost 192.168.1.1], { :timeout => 10 })
+    Dalli::Client.expects(:new).with(%w[localhost 192.168.1.1], { :timeout => 10 })
     store = ActiveSupport::Cache.lookup_store :mem_cache_store, "localhost", '192.168.1.1', :namespace => 'foo', :timeout => 10
     assert_kind_of(ActiveSupport::Cache::MemCacheStore, store)
     assert_equal 'foo', store.options[:namespace]