Batch touch parent records

[fixes #18606]

Make belongs_to use touch over touch_later when running the callbacks.

Add more tests and small method rename

Thanks Jeremy for the feedback.

7 files changed, 172 insertions, 7 deletions

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index 58a4694880..1844b29ccb 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -49,6 +49,7 @@ module ActiveRecord
   autoload :ModelSchema
   autoload :NestedAttributes
   autoload :NoTouching
+  autoload :TouchLater
   autoload :Persistence
   autoload :QueryCache
   autoload :Querying
diff --git a/activerecord/lib/active_record/associations/builder/belongs_to.rb b/activerecord/lib/active_record/associations/builder/belongs_to.rb
index ec135d49b7..97eb007f62 100644
--- a/activerecord/lib/active_record/associations/builder/belongs_to.rb
+++ b/activerecord/lib/active_record/associations/builder/belongs_to.rb
@@ -60,7 +60,7 @@ module ActiveRecord::Associations::Builder
       klass.attr_readonly cache_column if klass && klass.respond_to?(:attr_readonly)
     end
 
-    def self.touch_record(o, foreign_key, name, touch) # :nodoc:
+    def self.touch_record(o, foreign_key, name, touch, touch_method) # :nodoc:
       old_foreign_id = o.changed_attributes[foreign_key]
 
       if old_foreign_id
@@ -75,9 +75,9 @@ module ActiveRecord::Associations::Builder
 
         if old_record
           if touch != true
-            old_record.touch touch
+            old_record.send(touch_method, touch)
           else
-            old_record.touch
+            old_record.send(touch_method)
           end
         end
       end
@@ -85,9 +85,9 @@ module ActiveRecord::Associations::Builder
       record = o.send name
       if record && record.persisted?
         if touch != true
-          record.touch touch
+          record.send(touch_method, touch)
         else
-          record.touch
+          record.send(touch_method)
         end
       end
     end
@@ -98,7 +98,8 @@ module ActiveRecord::Associations::Builder
       touch       = reflection.options[:touch]
 
       callback = lambda { |record|
-        BelongsTo.touch_record(record, foreign_key, n, touch)
+        touch_method = touching_delayed_records? ? :touch : :touch_later
+        BelongsTo.touch_record(record, foreign_key, n, touch, touch_method)
       }
 
       model.after_save    callback, if: :changed?
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 93550a69f1..67490ecd97 100644
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -309,6 +309,7 @@ module ActiveRecord #:nodoc:
     include Aggregations
     include Transactions
     include NoTouching
+    include TouchLater
     include Reflection
     include Serialization
     include Store
diff --git a/activerecord/lib/active_record/persistence.rb b/activerecord/lib/active_record/persistence.rb
index a6176dffdb..a1e1073792 100644
--- a/activerecord/lib/active_record/persistence.rb
+++ b/activerecord/lib/active_record/persistence.rb
@@ -462,9 +462,10 @@ module ActiveRecord
     #   ball = Ball.new
     #   ball.touch(:updated_at)   # => raises ActiveRecordError
     #
-    def touch(*names, time: current_time_from_proper_timezone)
+    def touch(*names, time: nil)
       raise ActiveRecordError, "cannot touch on a new record object" unless persisted?
 
+      time ||= current_time_from_proper_timezone
       attributes = timestamp_attributes_for_update_in_model
       attributes.concat(names)
 
diff --git a/activerecord/lib/active_record/touch_later.rb b/activerecord/lib/active_record/touch_later.rb
new file mode 100644
index 0000000000..4352a0ffea
--- /dev/null
+++ b/activerecord/lib/active_record/touch_later.rb
@@ -0,0 +1,50 @@
+module ActiveRecord
+  # = Active Record Touch Later
+  module TouchLater
+    extend ActiveSupport::Concern
+
+    included do
+      before_commit_without_transaction_enrollment :touch_deferred_attributes
+    end
+
+    def touch_later(*names) # :nodoc:
+      raise ActiveRecordError, "cannot touch on a new record object" unless persisted?
+
+      @_defer_touch_attrs ||= timestamp_attributes_for_update_in_model
+      @_defer_touch_attrs |= names
+      @_touch_time = current_time_from_proper_timezone
+
+      surreptitiously_touch @_defer_touch_attrs
+      self.class.connection.add_transaction_record self
+    end
+
+    def touch(*names, time: nil) # :nodoc:
+      if has_defer_touch_attrs?
+        names |= @_defer_touch_attrs
+      end
+      super(*names, time: time)
+    end
+
+    private
+      def surreptitiously_touch(attrs)
+        attrs.each { |attr| write_attribute attr, @_touch_time }
+        clear_attribute_changes attrs
+      end
+
+      def touch_deferred_attributes
+        if has_defer_touch_attrs? && persisted?
+          @_touching_delayed_records = true
+          touch(*@_defer_touch_attrs, time: @_touch_time)
+          @_touching_delayed_records, @_defer_touch_attrs, @_touch_time = nil, nil, nil
+        end
+      end
+
+      def has_defer_touch_attrs?
+        defined?(@_defer_touch_attrs) && @_defer_touch_attrs.present?
+      end
+
+      def touching_delayed_records?
+        defined?(@_touching_delayed_records) && @_touching_delayed_records
+      end
+  end
+end
diff --git a/activerecord/test/cases/associations/belongs_to_associations_test.rb b/activerecord/test/cases/associations/belongs_to_associations_test.rb
index 47fd7345c8..95d00ab3a9 100644
--- a/activerecord/test/cases/associations/belongs_to_associations_test.rb
+++ b/activerecord/test/cases/associations/belongs_to_associations_test.rb
@@ -422,6 +422,24 @@ class BelongsToAssociationsTest < ActiveRecord::TestCase
     assert_queries(1) { line_item.touch }
   end
 
+  def test_belongs_to_with_touch_on_multiple_records
+    line_item = LineItem.create!(amount: 1)
+    line_item2 = LineItem.create!(amount: 2)
+    Invoice.create!(line_items: [line_item, line_item2])
+
+    assert_queries(1) do
+      LineItem.transaction do
+        line_item.touch
+        line_item2.touch
+      end
+    end
+
+    assert_queries(2) do
+      line_item.touch
+      line_item2.touch
+    end
+  end
+
   def test_belongs_to_with_touch_option_on_touch_without_updated_at_attributes
     assert_not LineItem.column_names.include?("updated_at")
 
diff --git a/activerecord/test/cases/touch_later_test.rb b/activerecord/test/cases/touch_later_test.rb
new file mode 100644
index 0000000000..11804ff90b
--- /dev/null
+++ b/activerecord/test/cases/touch_later_test.rb
@@ -0,0 +1,93 @@
+require 'cases/helper'
+require 'models/invoice'
+require 'models/line_item'
+require 'models/topic'
+
+class TouchLaterTest < ActiveRecord::TestCase
+
+  def test_touch_laster_raise_if_non_persisted
+    invoice = Invoice.new
+    Invoice.transaction do
+      refute invoice.persisted?
+      assert_raises(ActiveRecord::ActiveRecordError) do
+        invoice.touch_later
+      end
+    end
+  end
+
+  def test_touch_later_dont_set_dirty_attributes
+    invoice = Invoice.create!
+    invoice.touch_later
+    refute invoice.changed?
+  end
+
+  def test_touch_later_update_the_attributes
+    time = Time.now.utc - 25.days
+    topic = Topic.create!(updated_at: time, created_at: time)
+    assert_equal time.to_i, topic.updated_at.to_i
+    assert_equal time.to_i, topic.created_at.to_i
+
+    Topic.transaction do
+      topic.touch_later(:created_at)
+      assert_not_equal time.to_i, topic.updated_at.to_i
+      assert_not_equal time.to_i, topic.created_at.to_i
+
+      assert_equal time.to_i, topic.reload.updated_at.to_i
+      assert_equal time.to_i, topic.reload.created_at.to_i
+    end
+    assert_not_equal time.to_i, topic.reload.updated_at.to_i
+    assert_not_equal time.to_i, topic.reload.created_at.to_i
+  end
+
+  def test_touch_touches_immediately
+    time = Time.now.utc - 25.days
+    topic = Topic.create!(updated_at: time, created_at: time)
+    assert_equal time.to_i, topic.updated_at.to_i
+    assert_equal time.to_i, topic.created_at.to_i
+
+    Topic.transaction do
+      topic.touch_later(:created_at)
+      topic.touch
+
+      assert_not_equal time, topic.reload.updated_at
+      assert_not_equal time, topic.reload.created_at
+    end
+  end
+
+  def test_touch_later_an_association_dont_autosave_parent
+    time = Time.now.utc - 25.days
+    line_item = LineItem.create!(amount: 1)
+    invoice = Invoice.create!(line_items: [line_item])
+    invoice.touch(time: time)
+
+    Invoice.transaction do
+      line_item.update(amount: 2)
+      assert_equal time.to_i, invoice.reload.updated_at.to_i
+    end
+
+    assert_not_equal time.to_i, invoice.updated_at.to_i
+  end
+
+  def test_touch_touches_immediately_with_a_custom_time
+    time = Time.now.utc - 25.days
+    topic = Topic.create!(updated_at: time, created_at: time)
+    assert_equal time, topic.updated_at
+    assert_equal time, topic.created_at
+
+    Topic.transaction do
+      topic.touch_later(:created_at)
+      time = Time.now.utc - 2.days
+      topic.touch(time: time)
+
+      assert_equal time.to_i, topic.reload.updated_at.to_i
+      assert_equal time.to_i, topic.reload.created_at.to_i
+    end
+  end
+
+  def test_touch_later_dont_hit_the_db
+    invoice = Invoice.create!
+    assert_queries(0) do
+      invoice.touch_later
+    end
+  end
+end