intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 47 insertions, 0 deletions

diff --git a/library/cpp/monlib/metrics/ewma.h b/library/cpp/monlib/metrics/ewma.h
new file mode 100644
index 0000000000..9b2dad7cc5
--- /dev/null
+++ b/library/cpp/monlib/metrics/ewma.h
@@ -0,0 +1,47 @@
+#pragma once
+
+#include <util/datetime/base.h>
+#include <util/generic/ptr.h>
+
+#include <atomic>
+
+namespace NMonitoring {
+    class IGauge;
+
+    class IExpMovingAverage {
+    public:
+        virtual ~IExpMovingAverage() = default;
+        virtual void Tick() = 0;
+        virtual void Update(i64 value) = 0;
+        virtual double Rate() const = 0;
+        virtual void Reset() = 0;
+    };
+
+    using IExpMovingAveragePtr = THolder<IExpMovingAverage>;
+
+    class TEwmaMeter {
+    public:
+        // Creates a fake EWMA that will always return 0. Mostly for usage convenience
+        TEwmaMeter();
+        explicit TEwmaMeter(IExpMovingAveragePtr&& ewma);
+
+        TEwmaMeter(TEwmaMeter&& other);
+        TEwmaMeter& operator=(TEwmaMeter&& other);
+
+        void Mark();
+        void Mark(i64 value);
+
+        double Get();
+
+    private:
+        void TickIfNeeded();
+
+    private:
+        IExpMovingAveragePtr Ewma_;
+        std::atomic<ui64> LastTick_{TInstant::Now().Seconds()};
+    };
+
+    IExpMovingAveragePtr OneMinuteEwma(IGauge* gauge);
+    IExpMovingAveragePtr FiveMinuteEwma(IGauge* gauge);
+    IExpMovingAveragePtr FiveteenMinuteEwma(IGauge* gauge);
+} // namespace NMonitoring