gitlab-org--gitlab-foss/app/models/concerns/bulk_insertable_associations.rb

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# frozen_string_literal: true
##
# ActiveRecord model classes can mix in this concern if they own associations
# who declare themselves to be eligible for bulk-insertion via [BulkInsertSafe].
# This allows the caller to write items from [has_many] associations en-bloc
# when the owner is first created.
#
# This implementation currently has a few limitations:
# - only works for [has_many] relations
# - does not support the [:through] option
# - it cannot bulk-insert items that had previously been saved, nor can the
# owner of the association have previously been saved; if you attempt to
# so, an error will be raised
#
# @example
#
# class MergeRequestDiff < ApplicationRecord
# include BulkInsertableAssociations
#
# # target association class must `include BulkInsertSafe`
# has_many :merge_request_diff_commits
# end
#
# diff = MergeRequestDiff.new(...)
# diff.diff_commits << MergeRequestDiffCommit.build(...)
# BulkInsertableAssociations.with_bulk_insert do
# diff.save! # this will also write all `diff_commits` in bulk
# end
#
# Note that just like [BulkInsertSafe.bulk_insert!], validations will run for
# all items that are scheduled for bulk-insertions.
#
module BulkInsertableAssociations
extend ActiveSupport::Concern
class << self
def bulk_inserts_enabled?
Thread.current['bulk_inserts_enabled']
end
# All associations that are [BulkInsertSafe] and that as a result of calls to
# [save] or [save!] would be written to the database, will be inserted using
# [bulk_insert!] instead.
#
# Note that this will only work for entities that have not been persisted yet.
#
# @param [Boolean] enabled When [true], bulk-inserts will be attempted within
# the given block. If [false], bulk-inserts will be
# disabled. This behavior can be nested.
def with_bulk_insert(enabled: true)
previous = bulk_inserts_enabled?
Thread.current['bulk_inserts_enabled'] = enabled
yield
ensure
Thread.current['bulk_inserts_enabled'] = previous
end
end
def bulk_insert_associations!
self.class.reflections.each do |_, reflection|
_bulk_insert_association!(reflection)
end
end
private
def _bulk_insert_association!(reflection)
return unless _association_supports_bulk_inserts?(reflection)
association = self.association(reflection.name)
association_items = association.target
return if association_items.empty?
if association_items.any?(&:persisted?)
raise 'Bulk-insertion of already persisted association items is not currently supported'
end
_bulk_insert_configure_foreign_key(reflection, association_items)
association.klass.bulk_insert!(association_items, validate: false)
# reset relation:
# 1. we successfully inserted all items
# 2. when accessed we force to reload the relation
association.reset
end
def _association_supports_bulk_inserts?(reflection)
reflection.macro == :has_many &&
reflection.klass < BulkInsertSafe &&
!reflection.through_reflection? &&
association_cached?(reflection.name)
end
def _bulk_insert_configure_foreign_key(reflection, items)
primary_key_column = reflection.active_record_primary_key
raise "Classes including `BulkInsertableAssociations` must define a `primary_key`" unless primary_key_column
primary_key_value = self[primary_key_column]
raise "No value found for primary key `#{primary_key_column}`" unless primary_key_value
items.each do |item|
item[reflection.foreign_key] = primary_key_value
if reflection.type
item[reflection.type] = self.class.polymorphic_name
end
end
end
included do
delegate :bulk_inserts_enabled?, to: BulkInsertableAssociations
after_create :bulk_insert_associations!, if: :bulk_inserts_enabled?, prepend: true
end
end