diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/preloader.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/preloader.rb | 68 |
1 files changed, 38 insertions, 30 deletions
diff --git a/activerecord/lib/active_record/associations/preloader.rb b/activerecord/lib/active_record/associations/preloader.rb index 1ea0aeac3a..6b57e5093a 100644 --- a/activerecord/lib/active_record/associations/preloader.rb +++ b/activerecord/lib/active_record/associations/preloader.rb @@ -88,7 +88,6 @@ module ActiveRecord if records.empty? [] else - records.uniq! Array.wrap(associations).flat_map { |association| preloaders_on association, records, preload_scope } @@ -98,34 +97,34 @@ module ActiveRecord private # Loads all the given data into +records+ for the +association+. - def preloaders_on(association, records, scope) + def preloaders_on(association, records, scope, polymorphic_parent = false) case association when Hash - preloaders_for_hash(association, records, scope) - when Symbol - preloaders_for_one(association, records, scope) - when String - preloaders_for_one(association.to_sym, records, scope) + preloaders_for_hash(association, records, scope, polymorphic_parent) + when Symbol, String + preloaders_for_one(association, records, scope, polymorphic_parent) else raise ArgumentError, "#{association.inspect} was not recognized for preload" end end - def preloaders_for_hash(association, records, scope) + def preloaders_for_hash(association, records, scope, polymorphic_parent) association.flat_map { |parent, child| - loaders = preloaders_for_one parent, records, scope - - recs = loaders.flat_map(&:preloaded_records).uniq - loaders.concat Array.wrap(child).flat_map { |assoc| - preloaders_on assoc, recs, scope - } - loaders + grouped_records(parent, records, polymorphic_parent).flat_map do |reflection, reflection_records| + loaders = preloaders_for_reflection(reflection, reflection_records, scope) + recs = loaders.flat_map(&:preloaded_records) + child_polymorphic_parent = reflection && reflection.options[:polymorphic] + loaders.concat Array.wrap(child).flat_map { |assoc| + preloaders_on assoc, recs, scope, child_polymorphic_parent + } + loaders + end } end # Loads all the given data into +records+ for a singular +association+. # - # Functions by instantiating a preloader class such as Preloader::HasManyThrough and + # Functions by instantiating a preloader class such as Preloader::Association and # call the +run+ method for each passed in class in the +records+ argument. # # Not all records have the same class, so group then preload group on the reflection @@ -135,24 +134,25 @@ module ActiveRecord # Additionally, polymorphic belongs_to associations can have multiple associated # classes, depending on the polymorphic_type field. So we group by the classes as # well. - def preloaders_for_one(association, records, scope) - grouped_records(association, records).flat_map do |reflection, klasses| - klasses.map do |rhs_klass, rs| - loader = preloader_for(reflection, rs).new(rhs_klass, rs, reflection, scope) - loader.run self - loader + def preloaders_for_one(association, records, scope, polymorphic_parent) + grouped_records(association, records, polymorphic_parent) + .flat_map do |reflection, reflection_records| + preloaders_for_reflection reflection, reflection_records, scope end + end + + def preloaders_for_reflection(reflection, records, scope) + records.group_by { |record| record.association(reflection.name).klass }.map do |rhs_klass, rs| + preloader_for(reflection, rs).new(rhs_klass, rs, reflection, scope).run end end - def grouped_records(association, records) + def grouped_records(association, records, polymorphic_parent) h = {} records.each do |record| - next unless record - assoc = record.association(association) - next unless assoc.klass - klasses = h[assoc.reflection] ||= {} - (klasses[assoc.klass] ||= []) << record + reflection = record.class._reflect_on_association(association) + next if polymorphic_parent && !reflection || !record.association(association).klass + (h[reflection] ||= []) << record end h end @@ -163,10 +163,18 @@ module ActiveRecord @reflection = reflection end - def run(preloader); end + def run + self + end def preloaded_records - owners.flat_map { |owner| owner.association(reflection.name).target } + @preloaded_records ||= records_by_owner.flat_map(&:last) + end + + def records_by_owner + @records_by_owner ||= owners.each_with_object({}) do |owner, result| + result[owner] = Array(owner.association(reflection.name).target) + end end private |