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 | 145 |
1 files changed, 72 insertions, 73 deletions
diff --git a/activerecord/lib/active_record/associations/preloader/through_association.rb b/activerecord/lib/active_record/associations/preloader/through_association.rb index 9d44a02021..a6b7ab80a2 100644 --- a/activerecord/lib/active_record/associations/preloader/through_association.rb +++ b/activerecord/lib/active_record/associations/preloader/through_association.rb @@ -1,106 +1,105 @@ +# frozen_string_literal: true + module ActiveRecord module Associations class Preloader - module ThroughAssociation #:nodoc: - def through_reflection - reflection.through_reflection - end - - def source_reflection - reflection.source_reflection - end - - def associated_records_by_owner(preloader) - preloader.preload(owners, - through_reflection.name, - through_scope) - - through_records = owners.map do |owner| - association = owner.association through_reflection.name - - center = target_records_from_association(association) - [owner, Array(center)] - end - - reset_association owners, through_reflection.name - - middle_records = through_records.flat_map { |(_, rec)| rec } - - preloaders = preloader.preload(middle_records, - source_reflection.name, - reflection_scope) - + class ThroughAssociation < Association # :nodoc: + def run(preloader) + already_loaded = owners.first.association(through_reflection.name).loaded? + through_scope = through_scope() + reflection_scope = target_reflection_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, reflection_scope) @preloaded_records = preloaders.flat_map(&:preloaded_records) - middle_to_pl = preloaders.each_with_object({}) do |pl, h| - pl.owners.each { |middle| - h[middle] = pl - } - end - - through_records.each_with_object({}) do |(lhs, center), records_by_owner| - pl_to_middle = center.group_by { |record| middle_to_pl[record] } - - records_by_owner[lhs] = pl_to_middle.flat_map do |pl, middles| - rhs_records = middles.flat_map { |r| - association = r.association source_reflection.name - - target_records_from_association(association) - }.compact - - # Respect the order on `reflection_scope` if it exists, else use the natural order. - if reflection_scope.values[:order].present? - @id_map ||= id_to_index_map @preloaded_records - rhs_records.sort_by { |rhs| @id_map[rhs] } - else - rhs_records + owners.each do |owner| + through_records = Array(owner.association(through_reflection.name).target) + 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| + association = record.association(source_reflection.name) + target = association.target + association.reset if preload_scope + target + end + result.compact! + if reflection_scope + result.sort_by! { |rhs| preload_index[rhs] } if reflection_scope.order_values.any? + result.uniq! if reflection_scope.distinct_value end + associate_records_to_owner(owner, result) end end private - - def id_to_index_map(ids) - id_map = {} - ids.each_with_index { |id, index| id_map[id] = index } - id_map + def through_reflection + reflection.through_reflection end - def reset_association(owners, association_name) - should_reset = (through_scope != through_reflection.klass.unscoped) || - (reflection.options[:source_type] && through_reflection.collection?) + def source_reflection + reflection.source_reflection + end - # Don't cache the association - we would only be caching a subset - if should_reset - owners.each { |owner| - owner.association(association_name).reset - } + def preload_index + @preload_index ||= @preloaded_records.each_with_object({}).with_index do |(id, result), index| + result[id] = index end end def through_scope scope = through_reflection.klass.unscoped + options = reflection.options if options[:source_type] scope.where! reflection.foreign_type => options[:source_type] - else - unless reflection_scope.where_clause.empty? - scope.includes_values = Array(reflection_scope.values[:includes] || options[:source]) - scope.where_clause = reflection_scope.where_clause + elsif !reflection_scope.where_clause.empty? + scope.where_clause = reflection_scope.where_clause + values = reflection_scope.values + + if includes = values[:includes] + scope.includes!(source_reflection.name => includes) + else + scope.includes!(source_reflection.name) end - scope.references! reflection_scope.values[:references] - if scope.eager_loading? && order_values = reflection_scope.values[:order] + if values[:references] && !values[:references].empty? + scope.references!(values[:references]) + else + scope.references!(source_reflection.table_name) + end + + if joins = values[:joins] + scope.joins!(source_reflection.name => joins) + end + + if left_outer_joins = values[:left_outer_joins] + scope.left_outer_joins!(source_reflection.name => left_outer_joins) + end + + if scope.eager_loading? && order_values = values[:order] scope = scope.order(order_values) end end - scope + scope unless scope.empty_scope? end - def target_records_from_association(association) - association.loaded? ? association.target : association.reader + def target_reflection_scope + if preload_scope + reflection_scope.merge(preload_scope) + elsif reflection.scope + reflection_scope + else + nil + end end end end |