diff options
Diffstat (limited to 'app/models/preloaders/environments/deployment_preloader.rb')
-rw-r--r-- | app/models/preloaders/environments/deployment_preloader.rb | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/app/models/preloaders/environments/deployment_preloader.rb b/app/models/preloaders/environments/deployment_preloader.rb new file mode 100644 index 00000000000..fcf892698bb --- /dev/null +++ b/app/models/preloaders/environments/deployment_preloader.rb @@ -0,0 +1,43 @@ +# frozen_string_literal: true + +module Preloaders + module Environments + # This class is to batch-load deployments of multiple environments. + # The deployments to batch-load are fetched using UNION of N selects in a single query instead of default scoping with `IN (environment_id1, environment_id2 ...)`. + # See https://gitlab.com/gitlab-org/gitlab/-/issues/345672#note_761852224 for more details. + class DeploymentPreloader + attr_reader :environments + + def initialize(environments) + @environments = environments + end + + def execute_with_union(association_name, association_attributes) + load_deployment_association(association_name, association_attributes) + end + + private + + def load_deployment_association(association_name, association_attributes) + return unless environments.present? + + union_arg = environments.inject([]) do |result, environment| + result << environment.association(association_name).scope + end + + union_sql = Deployment.from_union(union_arg).to_sql + + deployments = Deployment + .from("(#{union_sql}) #{::Deployment.table_name}") + .preload(association_attributes) + + deployments_by_environment_id = deployments.index_by(&:environment_id) + + environments.each do |environment| + environment.association(association_name).target = deployments_by_environment_id[environment.id] + environment.association(association_name).loaded! + end + end + end + end +end |