ttl_memoizeable.rb in ttl_memoizeable-0.2.1

- old
+ new

@@ -5,27 +5,28 @@
 
 require_relative "ttl_memoizeable/version"
 
 module TTLMemoizeable
   TTLMemoizationError = Class.new(StandardError)
+  SetupMutex = Mutex.new
 
   def ttl_memoized_method(method_name, ttl: 1000)
     raise TTLMemoizationError, "Method not defined: #{method_name}" unless method_defined?(method_name) || private_method_defined?(method_name)
 
     ivar_name = method_name.to_s.gsub(/\??/, "") # remove trailing question marks
     time_based_ttl = ttl.is_a?(ActiveSupport::Duration)
     expired_ttl = time_based_ttl ? 1.year.ago : 1
 
-    ttl_variable_name = "@_ttl_for_#{ivar_name}".to_sym
-    mutex_variable_name = "@_mutex_for_#{ivar_name}".to_sym
-    value_variable_name = "@_value_for_#{ivar_name}".to_sym
+    ttl_variable_name = :"@_ttl_for_#{ivar_name}"
+    mutex_variable_name = :"@_mutex_for_#{ivar_name}"
+    value_variable_name = :"@_value_for_#{ivar_name}"
 
-    reset_memoized_value_method_name = "reset_memoized_value_for_#{method_name}".to_sym
-    setup_memoization_method_name = "_setup_memoization_for_#{method_name}".to_sym
-    decrement_ttl_method_name = "_decrement_ttl_for_#{method_name}".to_sym
-    ttl_exceeded_method_name = "_ttl_exceeded_for_#{method_name}".to_sym
-    extend_ttl_method_name = "_extend_ttl_for_#{method_name}".to_sym
+    reset_memoized_value_method_name = :"reset_memoized_value_for_#{method_name}"
+    setup_memoization_method_name = :"_setup_memoization_for_#{method_name}"
+    decrement_ttl_method_name = :"_decrement_ttl_for_#{method_name}"
+    ttl_exceeded_method_name = :"_ttl_exceeded_for_#{method_name}"
+    extend_ttl_method_name = :"_extend_ttl_for_#{method_name}"
 
     [
       reset_memoized_value_method_name, setup_memoization_method_name,
       decrement_ttl_method_name, ttl_exceeded_method_name, extend_ttl_method_name
     ].each do |potential_method_name|
@@ -42,26 +43,28 @@
 
         nil
       end
 
       define_method setup_memoization_method_name do
-        instance_variable_set(ttl_variable_name, expired_ttl) unless instance_variable_defined?(ttl_variable_name)
-        instance_variable_set(mutex_variable_name, Mutex.new) unless instance_variable_defined?(mutex_variable_name)
-        instance_variable_set(value_variable_name, nil) unless instance_variable_defined?(value_variable_name)
+        return if instance_variable_defined?(ttl_variable_name) && instance_variable_defined?(mutex_variable_name)
+
+        ::TTLMemoizeable::SetupMutex.synchronize do
+          instance_variable_set(ttl_variable_name, expired_ttl) unless instance_variable_defined?(ttl_variable_name)
+          instance_variable_set(mutex_variable_name, Mutex.new) unless instance_variable_defined?(mutex_variable_name)
+        end
       end
 
       define_method decrement_ttl_method_name do
         return if time_based_ttl
 
         instance_variable_set(ttl_variable_name, instance_variable_get(ttl_variable_name) - 1)
       end
 
       define_method ttl_exceeded_method_name do
-        instance_variable_get(ttl_variable_name) <= if time_based_ttl
-          ttl.ago
-        else
-          0
-        end
+        return true unless instance_variable_defined?(value_variable_name)
+
+        compared_to = time_based_ttl ? ttl.ago : 0
+        instance_variable_get(ttl_variable_name) <= compared_to
       end
 
       define_method extend_ttl_method_name do
         if time_based_ttl
           instance_variable_set(ttl_variable_name, Time.current)