some memoizing and hash equality performance optimizations

6 files changed, 17 insertions, 25 deletions

diff --git a/lib/arel/primitives/attribute.rb b/lib/arel/primitives/attribute.rb
index 78a519b35c..acc4d86a80 100644
--- a/lib/arel/primitives/attribute.rb
+++ b/lib/arel/primitives/attribute.rb
@@ -9,8 +9,8 @@ module Arel
       @relation, @name, @alias, @ancestor = relation, name, options[:alias], options[:ancestor]
     end
     
-    def alias_or_name
-      @alias || name
+    def named?(hypothetical_name)
+      (@alias || name).to_s == hypothetical_name.to_s
     end
     
     def aggregation?
@@ -57,12 +57,12 @@ module Arel
     include Transformations
     
     module Congruence
-      def self.included(klass)
-        klass.hash_on :name
-      end
-      
+      # def self.included(klass)
+      #   klass.hash_on :name
+      # end
+      # 
       def history
-        [self] + (ancestor ? [ancestor, ancestor.history].flatten : [])
+        @history ||= [self] + (ancestor ? [ancestor, ancestor.history].flatten : [])
       end
       
       def match?(other)
diff --git a/lib/arel/relations/compound.rb b/lib/arel/relations/compound.rb
index 7b6f3a46f8..663711760c 100644
--- a/lib/arel/relations/compound.rb
+++ b/lib/arel/relations/compound.rb
@@ -8,7 +8,7 @@ module Arel
              :to => :relation
     
     def attributes
-      relation.attributes.collect { |a| a.bind(self) }
+      @attributes ||= relation.attributes.collect { |a| a.bind(self) }
     end
   end
 end
\ No newline at end of file
diff --git a/lib/arel/relations/relation.rb b/lib/arel/relations/relation.rb
index 4653323514..b2f811cea2 100644
--- a/lib/arel/relations/relation.rb
+++ b/lib/arel/relations/relation.rb
@@ -136,7 +136,7 @@ module Arel
       end
       
       def find_attribute_matching_name(name)
-        attributes.detect { |a| a.alias_or_name.to_s == name.to_s }
+        attributes.detect { |a| a.named?(name) }
       end
       
       # TESTME - added relation_for(x)[x] because of AR
diff --git a/spec/arel/unit/primitives/attribute_spec.rb b/spec/arel/unit/primitives/attribute_spec.rb
index e21a5902d5..7e0155f84d 100644
--- a/spec/arel/unit/primitives/attribute_spec.rb
+++ b/spec/arel/unit/primitives/attribute_spec.rb
@@ -4,7 +4,7 @@ module Arel
   describe Attribute do
     before do
       @relation = Table.new(:users)
-      @attribute = Attribute.new(@relation, :id)
+      @attribute = @relation[:id]
     end
   
     describe Attribute::Transformations do
@@ -45,22 +45,21 @@ module Arel
     end
     
     describe Attribute::Congruence do
-      describe 'match?' do
-        
+      describe '#match?' do
         it "obtains if the attributes are identical" do
-          Attribute.new(@relation, :name).should be_match(Attribute.new(@relation, :name))
+          @attribute.should be_match(@attribute)
         end
       
         it "obtains if the attributes have an overlapping history" do
-          Attribute.new(@relation, :name, :ancestor => Attribute.new(@relation, :name)).should be_match(Attribute.new(@relation, :name))
-          Attribute.new(@relation, :name).should be_match(Attribute.new(@relation, :name, :ancestor => Attribute.new(@relation, :name)))
+          Attribute.new(@relation, :id, :ancestor => @attribute).should be_match(@attribute)
+          @attribute.should be_match(Attribute.new(@relation, :id, :ancestor => @attribute))
         end
       end
       
       describe '/' do
         before do
           @aliased_relation = @relation.alias
-          @doubly_aliased_relation = @aliased_relation.alias.alias.alias.alias
+          @doubly_aliased_relation = @aliased_relation.alias
         end
         
         describe 'when dividing two identical attributes' do
@@ -85,13 +84,6 @@ module Arel
           end
         end
       end
-      
-      describe 'hashing' do
-        it "implements hash equality" do
-          Attribute.new(@relation, 'name').should hash_the_same_as(Attribute.new(@relation, 'name'))
-          Attribute.new(@relation, 'name').should_not hash_the_same_as(Attribute.new(@relation, 'id'))
-        end
-      end
     end
     
     describe '#to_sql' do
diff --git a/spec/arel/unit/relations/insertion_spec.rb b/spec/arel/unit/relations/insertion_spec.rb
index 10b70a2036..0667aa665e 100644
--- a/spec/arel/unit/relations/insertion_spec.rb
+++ b/spec/arel/unit/relations/insertion_spec.rb
@@ -24,7 +24,7 @@ module Arel
         @insertion.to_sql.should be_like("
           INSERT
           INTO `users`
-          (`users`.`id`, `users`.`name`) VALUES (1, 'nick')
+          (`users`.`name`, `users`.`id`) VALUES ('nick', 1)
         ")
       end
       
diff --git a/spec/arel/unit/relations/update_spec.rb b/spec/arel/unit/relations/update_spec.rb
index f411781392..976e88dddc 100644
--- a/spec/arel/unit/relations/update_spec.rb
+++ b/spec/arel/unit/relations/update_spec.rb
@@ -10,7 +10,7 @@ module Arel
       it "manufactures sql updating attributes when given multiple attributes" do
         Update.new(@relation, @relation[:id] => 1, @relation[:name] => "nick").to_sql.should be_like("
           UPDATE `users`
-          SET `users`.`id` = 1, `users`.`name` = 'nick'
+          SET `users`.`name` = 'nick', `users`.`id` = 1
         ")
       end