Add latest changes from gitlab-org/gitlab@14-9-stable-eev14.9.0-rc42

1 files changed, 55 insertions, 0 deletions

diff --git a/lib/gitlab/safe_request_loader.rb b/lib/gitlab/safe_request_loader.rb
new file mode 100644
index 00000000000..89eca16c272
--- /dev/null
+++ b/lib/gitlab/safe_request_loader.rb
@@ -0,0 +1,55 @@
+# frozen_string_literal: true
+
+module Gitlab
+  class SafeRequestLoader
+    def self.execute(args, &block)
+      new(**args).execute(&block)
+    end
+
+    def initialize(resource_key:, resource_ids:, default_value: nil)
+      @resource_key = resource_key
+      @resource_ids = resource_ids.uniq
+      @default_value = default_value
+      @resource_data = {}
+    end
+
+    def execute(&block)
+      raise ArgumentError, 'Block is mandatory' unless block_given?
+
+      load_resource_data
+      remove_loaded_resource_ids
+
+      update_resource_data(&block)
+
+      resource_data
+    end
+
+    private
+
+    attr_reader :resource_key, :resource_ids, :default_value, :resource_data, :missing_resource_ids
+
+    def load_resource_data
+      @resource_data = Gitlab::SafeRequestStore.fetch(resource_key) { resource_data }
+    end
+
+    def remove_loaded_resource_ids
+      # Look up only the IDs we need
+      @missing_resource_ids = resource_ids - resource_data.keys
+    end
+
+    def update_resource_data(&block)
+      return if missing_resource_ids.blank?
+
+      reloaded_resource_data = yield(missing_resource_ids)
+
+      @resource_data.merge!(reloaded_resource_data)
+
+      mark_absent_values
+    end
+
+    def mark_absent_values
+      absent = (missing_resource_ids - resource_data.keys).to_h { [_1, default_value] }
+      @resource_data.merge!(absent)
+    end
+  end
+end