Performance: Better query for ASSOCIATION_ids. Select only ids if the…

… association hasn't been loaded.

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

activerecord/lib/active_record/associations.rb

@@ -1304,7 +1304,11 @@ def collection_reader_method(reflection, association_proxy_class)
           end
 
           define_method("#{reflection.name.to_s.singularize}_ids") do
-            send(reflection.name).map { |record| record.id }
+            if send(reflection.name).loaded?
+              send(reflection.name).map(&:id)
+            else
+              send(reflection.name).all(:select => "#{reflection.quoted_table_name}.id").map(&:id)
+            end
           end
         end
 

activerecord/test/cases/associations/has_and_belongs_to_many_associations_test.rb

@@ -223,10 +223,10 @@ def test_build
     devel = Developer.find(1)
     proj = assert_no_queries { devel.projects.build("name" => "Projekt") }
     assert !devel.projects.loaded?
-    
+
     assert_equal devel.projects.last, proj
     assert devel.projects.loaded?
-    
+
     assert proj.new_record?
     devel.save
     assert !proj.new_record?
@@ -251,10 +251,10 @@ def test_create
     devel = Developer.find(1)
     proj = devel.projects.create("name" => "Projekt")
     assert !devel.projects.loaded?
-    
+
     assert_equal devel.projects.last, proj
     assert devel.projects.loaded?
-    
+
     assert !proj.new_record?
     assert_equal Developer.find(1).projects.sort_by(&:id).last, proj  # prove join table is updated
   end
@@ -274,10 +274,10 @@ def test_create_by_new_record
 
   def test_creation_respects_hash_condition
     post = categories(:general).post_with_conditions.build(:body => '')
-    
+
     assert        post.save
     assert_equal  'Yet Another Testing Title', post.title
-    
+
     another_post = categories(:general).post_with_conditions.create(:body => '')
 
     assert        !another_post.new_record?
@@ -288,7 +288,7 @@ def test_uniq_after_the_fact
     dev = developers(:jamis)
     dev.projects << projects(:active_record)
     dev.projects << projects(:active_record)
-    
+
     assert_equal 3, dev.projects.size
     assert_equal 1, dev.projects.uniq.size
   end
@@ -415,13 +415,13 @@ def test_include_uses_array_include_after_loaded
     project.developers.class # force load target
 
     developer = project.developers.first
-    
+
     assert_no_queries do
       assert project.developers.loaded?
       assert project.developers.include?(developer)
     end
   end
-  
+
   def test_include_checks_if_record_exists_if_target_not_loaded
     project = projects(:active_record)
     developer = project.developers.first
@@ -641,6 +641,22 @@ def test_get_ids
     assert_equal [projects(:active_record).id], developers(:jamis).project_ids
   end
 
+  def test_get_ids_for_loaded_associations
+    developer = developers(:david)
+    developer.projects(true)
+    assert_queries(0) do
+      developer.project_ids
+      developer.project_ids
+    end
+  end
+
+  def test_get_ids_for_unloaded_associations_does_not_load_them
+    developer = developers(:david)
+    assert !developer.projects.loaded?
+    assert_equal projects(:active_record, :action_controller).map(&:id).sort, developer.project_ids.sort
+    assert !developer.projects.loaded?
+  end
+
   def test_assign_ids
     developer = Developer.new("name" => "Joe")
     developer.project_ids = projects(:active_record, :action_controller).map(&:id)

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -384,7 +384,7 @@ def test_build
     company = companies(:first_firm)
     new_client = assert_no_queries { company.clients_of_firm.build("name" => "Another Client") }
     assert !company.clients_of_firm.loaded?
-    
+
     assert_equal "Another Client", new_client.name
     assert new_client.new_record?
     assert_equal new_client, company.clients_of_firm.last
@@ -416,7 +416,7 @@ def test_collection_size_twice_for_regressions
   def test_build_many
     company = companies(:first_firm)
     new_clients = assert_no_queries { company.clients_of_firm.build([{"name" => "Another Client"}, {"name" => "Another Client II"}]) }
-    
+
     assert_equal 2, new_clients.size
     company.name += '-changed'
     assert_queries(3) { assert company.save }
@@ -655,10 +655,10 @@ def test_dependent_association_respects_optional_sanitized_conditions_on_delete
 
   def test_creation_respects_hash_condition
     ms_client = companies(:first_firm).clients_like_ms_with_hash_conditions.build
-    
+
     assert        ms_client.save
     assert_equal  'Microsoft', ms_client.name
-    
+
     another_ms_client = companies(:first_firm).clients_like_ms_with_hash_conditions.create
 
     assert        !another_ms_client.new_record?
@@ -830,6 +830,22 @@ def test_get_ids
     assert_equal [companies(:first_client).id, companies(:second_client).id], companies(:first_firm).client_ids
   end
 
+  def test_get_ids_for_loaded_associations
+    company = companies(:first_firm)
+    company.clients(true)
+    assert_queries(0) do
+      company.client_ids
+      company.client_ids
+    end
+  end
+
+  def test_get_ids_for_unloaded_associations_does_not_load_them
+    company = companies(:first_firm)
+    assert !company.clients.loaded?
+    assert_equal [companies(:first_client).id, companies(:second_client).id], company.client_ids
+    assert !company.clients.loaded?
+  end
+
   def test_assign_ids
     firm = Firm.new("name" => "Apple")
     firm.client_ids = [companies(:first_client).id, companies(:second_client).id]
@@ -900,7 +916,7 @@ def test_dynamic_find_all_order_should_override_association_limit_for_through
     assert_equal 4, authors(:david).limited_comments.find(:all, :conditions => "comments.type = 'SpecialComment'", :limit => 9_000).length
     assert_equal 4, authors(:david).limited_comments.find_all_by_type('SpecialComment', :limit => 9_000).length
   end
-  
+
   def test_find_all_include_over_the_same_table_for_through
     assert_equal 2, people(:michael).posts.find(:all, :include => :people).length
   end
@@ -937,13 +953,13 @@ def test_include_checks_if_record_exists_if_target_not_loaded
   def test_include_loads_collection_if_target_uses_finder_sql
     firm = companies(:first_firm)
     client = firm.clients_using_sql.first
-    
+
     firm.reload
     assert ! firm.clients_using_sql.loaded?
     assert firm.clients_using_sql.include?(client)
     assert firm.clients_using_sql.loaded?
   end
-  
+
 
   def test_include_returns_false_for_non_matching_record_to_verify_scoping
     firm = companies(:first_firm)

activerecord/test/cases/associations/has_many_through_associations_test.rb

@@ -200,4 +200,24 @@ def test_dynamic_find_should_respect_association_include
   def test_count_with_include_should_alias_join_table
     assert_equal 2, people(:michael).posts.count(:include => :readers)
   end
+
+  def test_get_ids
+    assert_equal [posts(:welcome).id, posts(:authorless).id], people(:michael).post_ids
+  end
+
+  def test_get_ids_for_loaded_associations
+    person = people(:michael)
+    person.posts(true)
+    assert_queries(0) do
+      person.post_ids
+      person.post_ids
+    end
+  end
+
+  def test_get_ids_for_unloaded_associations_does_not_load_them
+    person = people(:michael)
+    assert !person.posts.loaded?
+    assert_equal [posts(:welcome).id, posts(:authorless).id], person.post_ids
+    assert !person.posts.loaded?
+  end
 end