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.

4 files changed, 60 insertions, 7 deletions

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