From 30a652ad41428b922b1ed637f491776f1f1dff13 Mon Sep 17 00:00:00 2001 From: Rick Olson Date: Sun, 30 Sep 2007 06:47:20 +0000 Subject: Make size for has_many :through use counter cache if it exists. Closes #9734 [xaviershay] git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7692 5ecf4fe2-1ee6-0310-87b1-e25e094e27de --- activerecord/CHANGELOG | 2 ++ .../associations/has_many_through_association.rb | 12 +++++++++++- activerecord/test/associations/join_model_test.rb | 9 +++++++++ 3 files changed, 22 insertions(+), 1 deletion(-) diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG index b0c3a3179e..9372adb583 100644 --- a/activerecord/CHANGELOG +++ b/activerecord/CHANGELOG @@ -1,5 +1,7 @@ *2.0.0 [Preview Release]* (September 29th, 2007) [Includes duplicates of changes from 1.14.2 - 1.15.3] +* Make size for has_many :through use counter cache if it exists. Closes #9734 [xaviershay] + * Remove DB2 adapter since IBM chooses to maintain their own adapter instead. [Jeremy Kemper] * Extract Oracle, SQLServer, and Sybase adapters into gems. [Jeremy Kemper] diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb index de0d7cc8a9..62839c4637 100644 --- a/activerecord/lib/active_record/associations/has_many_through_association.rb +++ b/activerecord/lib/active_record/associations/has_many_through_association.rb @@ -100,7 +100,9 @@ module ActiveRecord # calling collection.size if it has. If it's more likely than not that the collection does have a size larger than zero # and you need to fetch that collection afterwards, it'll take one less SELECT query if you use length. def size - loaded? ? @target.size : count + return @owner.send(:read_attribute, cached_counter_attribute_name) if has_cached_counter? + return @target.size if loaded? + return count end # Calculate sum using SQL, not Enumerable @@ -258,6 +260,14 @@ module ActiveRecord end alias_method :sql_conditions, :conditions + + def has_cached_counter? + @owner.attribute_present?(cached_counter_attribute_name) + end + + def cached_counter_attribute_name + "#{@reflection.name}_count" + end end end end diff --git a/activerecord/test/associations/join_model_test.rb b/activerecord/test/associations/join_model_test.rb index d18c878733..d92a0c760a 100644 --- a/activerecord/test/associations/join_model_test.rb +++ b/activerecord/test/associations/join_model_test.rb @@ -457,6 +457,15 @@ class AssociationsJoinModelTest < Test::Unit::TestCase assert !author.comments.loaded? end + uses_mocha('has_many_through_collection_size_uses_counter_cache_if_it_exists') do + def test_has_many_through_collection_size_uses_counter_cache_if_it_exists + author = authors(:david) + author.stubs(:read_attribute).with('comments_count').returns(100) + assert_equal 100, author.comments.size + assert !author.comments.loaded? + end + end + def test_adding_junk_to_has_many_through_should_raise_type_mismatch assert_raise(ActiveRecord::AssociationTypeMismatch) { posts(:thinking).tags << "Uhh what now?" } end -- cgit v1.2.3