refactor the method cache objects to have a superclass

3 files changed, 41 insertions, 51 deletions

diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 2fd2ea896b..c07fd67216 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -28,6 +28,31 @@ module ActiveRecord
       end
     }
 
+    class AttributeMethodCache
+      include Mutex_m
+
+      def initialize
+        super
+        @module = Module.new
+        @method_cache = {}
+      end
+
+      def [](name)
+        synchronize do
+          @method_cache.fetch(name) {
+            safe_name = name.unpack('h*').first
+            temp_method = "__temp__#{safe_name}"
+            ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
+            @module.module_eval method_body(temp_method, safe_name), __FILE__, __LINE__
+            @method_cache[name] = @module.instance_method temp_method
+          }
+        end
+      end
+
+      private
+      def method_body; raise NotImplementedError; end
+    end
+
     module ClassMethods
       def inherited(child_class) #:nodoc:
         child_class.initialize_generated_modules
diff --git a/activerecord/lib/active_record/attribute_methods/read.rb b/activerecord/lib/active_record/attribute_methods/read.rb
index d43f4b55e8..c7d861a957 100644
--- a/activerecord/lib/active_record/attribute_methods/read.rb
+++ b/activerecord/lib/active_record/attribute_methods/read.rb
@@ -1,15 +1,8 @@
 module ActiveRecord
   module AttributeMethods
     module Read
-      ReaderMethodCache = Class.new {
-        include Mutex_m
-
-        def initialize
-          super
-          @module = Module.new
-          @method_cache = {}
-        end
-
+      ReaderMethodCache = Class.new(AttributeMethodCache) {
+        private
         # We want to generate the methods via module_eval rather than
         # define_method, because define_method is slower on dispatch.
         # Evaluating many similar methods may use more memory as the instruction
@@ -28,24 +21,13 @@ module ActiveRecord
         # to allocate an object on each call to the attribute method.
         # Making it frozen means that it doesn't get duped when used to
         # key the @attributes_cache in read_attribute.
-        def [](name)
-          synchronize do
-            @method_cache.fetch(name) {
-              safe_name = name.unpack('h*').first
-              temp_method = "__temp__#{safe_name}"
-
-              ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
-
-              @module.module_eval <<-STR, __FILE__, __LINE__ + 1
-                def #{temp_method}
-                  name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{safe_name}
-                  read_attribute(name) { |n| missing_attribute(n, caller) }
-                end
-              STR
-
-              @method_cache[name] = @module.instance_method temp_method
-            }
+        def method_body(method_name, const_name)
+          <<-EOMETHOD
+          def #{method_name}
+            name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{const_name}
+            read_attribute(name) { |n| missing_attribute(n, caller) }
           end
+          EOMETHOD
         end
       }.new
 
diff --git a/activerecord/lib/active_record/attribute_methods/write.rb b/activerecord/lib/active_record/attribute_methods/write.rb
index 813a85d2f7..f865f0b2c8 100644
--- a/activerecord/lib/active_record/attribute_methods/write.rb
+++ b/activerecord/lib/active_record/attribute_methods/write.rb
@@ -1,33 +1,16 @@
 module ActiveRecord
   module AttributeMethods
     module Write
-      WriterMethodCache = Class.new {
-        include Mutex_m
+      WriterMethodCache = Class.new(AttributeMethodCache) {
+        private
 
-        def initialize
-          super
-          @module = Module.new
-          @method_cache = {}
-        end
-
-        def [](name)
-          synchronize do
-            @method_cache.fetch(name) {
-              safe_name = name.unpack('h*').first
-              temp_method = "__temp__#{safe_name}="
-
-              ActiveRecord::AttributeMethods::AttrNames.set_name_cache safe_name, name
-
-              @module.module_eval <<-STR, __FILE__, __LINE__ + 1
-                def #{temp_method}(value)
-                  name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{safe_name}
-                  write_attribute(name, value)
-                end
-              STR
-
-              @method_cache[name] = @module.instance_method temp_method
-            }
+        def method_body(method_name, const_name)
+          <<-EOMETHOD
+          def #{method_name}(value)
+            name = ::ActiveRecord::AttributeMethods::AttrNames::ATTR_#{const_name}
+            write_attribute(name, value)
           end
+          EOMETHOD
         end
       }.new