Performance improvements

lib/acts_as_taggable_on/taggable/core.rb

@@ -217,7 +217,7 @@ def set_tag_list_on(context, new_list)
       end
 
       def tagging_contexts
-        self.class.tag_types.map(&:to_s) + custom_contexts
+        (self.class.tag_types.map(&:to_s) + custom_contexts).uniq
       end
 
       def taggable_tenant

lib/acts_as_taggable_on/taggable/ownership.rb

@@ -90,6 +90,7 @@ def reload(*args)
         super(*args)
       end
 
+      # This looks duplicated from taggable/core.rb
       def save_owned_tags
         tagging_contexts.each do |context|
           cached_owned_tag_list_on(context).each do |owner, tag_list|

lib/acts_as_taggable_on/tagging.rb

@@ -28,12 +28,15 @@ class Tagging < ActsAsTaggableOn.base_class.constantize # :nodoc:
     private
 
     def remove_unused_tags
-      if ActsAsTaggableOn.remove_unused_tags
-        if ActsAsTaggableOn.tags_counter
-          tag.destroy if tag.reload.taggings_count.zero?
-        elsif tag.reload.taggings.none?
-          tag.destroy
-        end
+      return unless ActsAsTaggableOn.remove_unused_tags
+
+      tag.reload if association(:tag).loaded?
+      if ActsAsTaggableOn.tags_counter
+        tag.destroy if tag.taggings_count.zero?
+      elsif tag.taggings.none?
+        # We already know there is no taggings, but the depended: :destroy will
+        # fire a query nonetheless, can we avoid it ?
+        tag.destroy
       end
     end
   end