Introduce "polling_interval_multiplier" as application setting

Implement module for setting "Poll-Interval" response header.
Return 429 in ETag caching middleware when polling is disabled.

1 files changed, 22 insertions, 0 deletions

diff --git a/lib/gitlab/polling_interval.rb b/lib/gitlab/polling_interval.rb
new file mode 100644
index 00000000000..c44bb1cd14d
--- /dev/null
+++ b/lib/gitlab/polling_interval.rb
@@ -0,0 +1,22 @@
+module Gitlab
+  class PollingInterval
+    include Gitlab::CurrentSettings
+
+    HEADER_NAME = 'Poll-Interval'.freeze
+
+    def self.set_header(response, interval:)
+      if polling_enabled?
+        multiplier = current_application_settings.polling_interval_multiplier
+        value = (interval * multiplier).to_i
+      else
+        value = -1
+      end
+
+      response.headers[HEADER_NAME] = value
+    end
+
+    def self.polling_enabled?
+      !current_application_settings.polling_interval_multiplier.zero?
+    end
+  end
+end