1 files changed, 45 insertions, 0 deletions
diff --git a/lib/gitlab/usage/metrics/instrumentations/redis_hll_metric.rb b/lib/gitlab/usage/metrics/instrumentations/redis_hll_metric.rb
new file mode 100644
index 00000000000..140d56f0d42
--- /dev/null
+++ b/lib/gitlab/usage/metrics/instrumentations/redis_hll_metric.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Usage
+    module Metrics
+      module Instrumentations
+        class RedisHLLMetric < BaseMetric
+          # Usage example
+          #
+          # class CountUsersVisitingAnalyticsValuestreamMetric < RedisHLLMetric
+          #   event_names :g_analytics_valuestream
+          # end
+          class << self
+            def event_names(events = nil)
+              @metric_events = events
+            end
+
+            attr_reader :metric_events
+          end
+
+          def value
+            redis_usage_data do
+              event_params = time_constraints.merge(event_names: self.class.metric_events)
+
+              Gitlab::UsageDataCounters::HLLRedisCounter.unique_events(**event_params)
+            end
+          end
+
+          private
+
+          def time_constraints
+            case time_frame
+            when '28d'
+              { start_date: 4.weeks.ago.to_date, end_date: Date.current }
+            when '7d'
+              { start_date: 7.days.ago.to_date, end_date: Date.current }
+            else
+              raise "Unknown time frame: #{time_frame} for TimeConstraint"
+            end
+          end
+        end
+      end
+    end
+  end
+end