diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/preloader/through_association.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/preloader/through_association.rb | 70 |
1 files changed, 41 insertions, 29 deletions
diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb index db89b77629..bec1c4c94a 100644 --- a/activerecord/lib/active_record/associations/preloader/through_association.rb +++ b/activerecord/lib/active_record/associations/preloader/through_association.rb @@ -4,45 +4,57 @@ module ActiveRecord module Associations class Preloader class ThroughAssociation < Association # :nodoc: - def run(preloader) - already_loaded = owners.first.association(through_reflection.name).loaded? - through_scope = through_scope() - through_preloaders = preloader.preload(owners, through_reflection.name, through_scope) - middle_records = through_preloaders.flat_map(&:preloaded_records) - preloaders = preloader.preload(middle_records, source_reflection.name, scope) - @preloaded_records = preloaders.flat_map(&:preloaded_records) - - owners.each do |owner| - through_records = Array(owner.association(through_reflection.name).target) - - if already_loaded + PRELOADER = ActiveRecord::Associations::Preloader.new + + def initialize(*) + super + @already_loaded = owners.first.association(through_reflection.name).loaded? + end + + def preloaded_records + @preloaded_records ||= source_preloaders.flat_map(&:preloaded_records) + end + + def records_by_owner + return @records_by_owner if defined?(@records_by_owner) + source_records_by_owner = source_preloaders.map(&:records_by_owner).reduce(:merge) + through_records_by_owner = through_preloaders.map(&:records_by_owner).reduce(:merge) + + @records_by_owner = owners.each_with_object({}) do |owner, result| + through_records = through_records_by_owner[owner] || [] + + if @already_loaded if source_type = reflection.options[:source_type] through_records = through_records.select do |record| record[reflection.foreign_type] == source_type end end - else - owner.association(through_reflection.name).reset if through_scope end - result = through_records.flat_map do |record| - record.association(source_reflection.name).target + records = through_records.flat_map do |record| + source_records_by_owner[record] end - result.compact! - result.sort_by! { |rhs| preload_index[rhs] } if scope.order_values.any? - result.uniq! if scope.distinct_value - associate_records_to_owner(owner, result) - end - - unless scope.empty_scope? - middle_records.each do |owner| - owner.association(source_reflection.name).reset if owner - end + records.compact! + records.sort_by! { |rhs| preload_index[rhs] } if scope.order_values.any? + records.uniq! if scope.distinct_value + result[owner] = records end end private + def source_preloaders + @source_preloaders ||= PRELOADER.preload(middle_records, source_reflection.name, scope) + end + + def middle_records + through_preloaders.flat_map(&:preloaded_records) + end + + def through_preloaders + @through_preloaders ||= PRELOADER.preload(owners, through_reflection.name, through_scope) + end + def through_reflection reflection.through_reflection end @@ -52,8 +64,8 @@ module ActiveRecord end def preload_index - @preload_index ||= @preloaded_records.each_with_object({}).with_index do |(id, result), index| - result[id] = index + @preload_index ||= preloaded_records.each_with_object({}).with_index do |(record, result), index| + result[record] = index end end @@ -96,7 +108,7 @@ module ActiveRecord end end - scope unless scope.empty_scope? + scope end end end |