1 files changed, 92 insertions, 0 deletions
diff --git a/app/finders/packages/build_infos_for_many_packages_finder.rb b/app/finders/packages/build_infos_for_many_packages_finder.rb
new file mode 100644
index 00000000000..8f9805f51d0
--- /dev/null
+++ b/app/finders/packages/build_infos_for_many_packages_finder.rb
@@ -0,0 +1,92 @@
+# frozen_string_literal: true
+
+module Packages
+  # TODO rename to BuildInfosFinder when cleaning up packages_graphql_pipelines_resolver
+  # https://gitlab.com/gitlab-org/gitlab/-/issues/358432
+  class BuildInfosForManyPackagesFinder
+    include ActiveRecord::ConnectionAdapters::Quoting
+
+    MAX_PAGE_SIZE = 100
+
+    def initialize(package_ids, params)
+      @package_ids = package_ids
+      @params = params
+    end
+
+    def execute
+      return Packages::BuildInfo.none if @package_ids.blank?
+
+      # This is a highly custom query that
+      # will not be re-used elsewhere
+      # rubocop: disable CodeReuse/ActiveRecord
+      query = Packages::Package.id_in(@package_ids)
+                .select('build_infos.*')
+                .from([Packages::Package.arel_table, lateral_query.arel.lateral.as('build_infos')])
+                .order('build_infos.id DESC')
+
+      # We manually select build_infos fields from the lateral query.
+      # Thus, we need to instruct ActiveRecord that returned rows are
+      # actually Packages::BuildInfo objects
+      Packages::BuildInfo.find_by_sql(query.to_sql)
+      # rubocop: enable CodeReuse/ActiveRecord
+    end
+
+    private
+
+    def lateral_query
+      order_direction = last ? :asc : :desc
+
+      # This is a highly custom query that
+      # will not be re-used elsewhere
+      # rubocop: disable CodeReuse/ActiveRecord
+      where_condition = Packages::BuildInfo.arel_table[:package_id]
+                          .eq(Arel.sql("#{Packages::Package.table_name}.id"))
+      build_infos = ::Packages::BuildInfo.without_empty_pipelines
+                      .where(where_condition)
+                      .order(id: order_direction)
+                      .limit(max_rows_per_package_id)
+      # rubocop: enable CodeReuse/ActiveRecord
+      apply_cursor(build_infos)
+    end
+
+    def max_rows_per_package_id
+      limit = [first, last, max_page_size, MAX_PAGE_SIZE].compact.min
+      limit += 1 if support_next_page
+      limit
+    end
+
+    def apply_cursor(build_infos)
+      if before
+        build_infos.with_pipeline_id_greater_than(before)
+      elsif after
+        build_infos.with_pipeline_id_less_than(after)
+      else
+        build_infos
+      end
+    end
+
+    def first
+      @params[:first]
+    end
+
+    def last
+      @params[:last]
+    end
+
+    def max_page_size
+      @params[:max_page_size]
+    end
+
+    def before
+      @params[:before]
+    end
+
+    def after
+      @params[:after]
+    end
+
+    def support_next_page
+      @params[:support_next_page]
+    end
+  end
+end