diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/preloader/association.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/preloader/association.rb | 71 |
1 files changed, 37 insertions, 34 deletions
diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb index d6f7359055..4c7b0e6f07 100644 --- a/activerecord/lib/active_record/associations/preloader/association.rb +++ b/activerecord/lib/active_record/associations/preloader/association.rb @@ -4,29 +4,43 @@ module ActiveRecord module Associations class Preloader class Association #:nodoc: - attr_reader :preloaded_records - def initialize(klass, owners, reflection, preload_scope) @klass = klass @owners = owners @reflection = reflection @preload_scope = preload_scope @model = owners.first && owners.first.class - @preloaded_records = [] end - def run(preloader) - records = load_records do |record| - owner = owners_by_key[convert_key(record[association_key_name])] - association = owner.association(reflection.name) - association.set_inverse_instance(record) + def run + if !preload_scope || preload_scope.empty_scope? + owners.each do |owner| + associate_records_to_owner(owner, records_by_owner[owner] || []) + end + else + # Custom preload scope is used and + # the association can not be marked as loaded + # Loading into a Hash instead + records_by_owner end + self + end - owners.each do |owner| - associate_records_to_owner(owner, records[convert_key(owner[owner_key_name])] || []) + def records_by_owner + # owners can be duplicated when a relation has a collection association join + # #compare_by_identity makes such owners different hash keys + @records_by_owner ||= preloaded_records.each_with_object({}.compare_by_identity) do |record, result| + owners_by_key[convert_key(record[association_key_name])].each do |owner| + (result[owner] ||= []) << record + end end end + def preloaded_records + return @preloaded_records if defined?(@preloaded_records) + @preloaded_records = owner_keys.empty? ? [] : records_for(owner_keys) + end + private attr_reader :owners, :reflection, :preload_scope, :model, :klass @@ -42,11 +56,10 @@ module ActiveRecord def associate_records_to_owner(owner, records) association = owner.association(reflection.name) - association.loaded! if reflection.collection? - association.target.concat(records) + association.target = records else - association.target = records.first unless records.empty? + association.target = records.first end end @@ -55,13 +68,10 @@ module ActiveRecord end def owners_by_key - unless defined?(@owners_by_key) - @owners_by_key = owners.each_with_object({}) do |owner, h| - key = convert_key(owner[owner_key_name]) - h[key] = owner if key - end + @owners_by_key ||= owners.each_with_object({}) do |owner, result| + key = convert_key(owner[owner_key_name]) + (result[key] ||= []) << owner if key end - @owners_by_key end def key_conversion_required? @@ -88,23 +98,16 @@ module ActiveRecord @model.type_for_attribute(owner_key_name).type end - def load_records(&block) - return {} if owner_keys.empty? - # Some databases impose a limit on the number of ids in a list (in Oracle it's 1000) - # Make several smaller queries if necessary or make one query if the adapter supports it - slices = owner_keys.each_slice(klass.connection.in_clause_length || owner_keys.size) - @preloaded_records = slices.flat_map do |slice| - records_for(slice, &block) - end - @preloaded_records.group_by do |record| - convert_key(record[association_key_name]) + def records_for(ids) + scope.where(association_key_name => ids).load do |record| + # Processing only the first owner + # because the record is modified but not an owner + owner = owners_by_key[convert_key(record[association_key_name])].first + association = owner.association(reflection.name) + association.set_inverse_instance(record) end end - def records_for(ids, &block) - scope.where(association_key_name => ids).load(&block) - end - def scope @scope ||= build_scope end @@ -116,7 +119,7 @@ module ActiveRecord def build_scope scope = klass.scope_for_association - if reflection.type + if reflection.type && !reflection.through_reflection? scope.where!(reflection.type => model.polymorphic_name) end |