Intermediate changes

4 files changed, 176 insertions, 0 deletions

diff --git a/yt/yt/core/misc/moving_average-inl.h b/yt/yt/core/misc/moving_average-inl.h
new file mode 100644
index 00000000000..2dcbd981859
--- /dev/null
+++ b/yt/yt/core/misc/moving_average-inl.h
@@ -0,0 +1,67 @@
+#ifndef MOVING_AVERAGE_INL_H_
+#error "Direct inclusion of this file is not allowed, include moving_average.h"
+// For the sake of sane code completion.
+#include "moving_average.h"
+#endif
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class TValue>
+TMovingAverage<TValue>::TMovingAverage(int windowSize)
+{
+    SetWindowSize(windowSize);
+}
+
+template <class TValue>
+void TMovingAverage<TValue>::AddValue(TValue value)
+{
+    Total_ += value;
+    Values_.push(std::move(value));
+
+    RemoveOldValues();
+}
+
+template <class TValue>
+std::optional<TValue> TMovingAverage<TValue>::GetAverage() const
+{
+    if (Values_.empty()) {
+        return {};
+    }
+
+    return Total_ / std::ssize(Values_);
+}
+
+template <class TValue>
+void TMovingAverage<TValue>::SetWindowSize(int windowSize)
+{
+    YT_VERIFY(windowSize >= 0);
+
+    WindowSize_ = windowSize;
+
+    RemoveOldValues();
+}
+
+template <class TValue>
+void TMovingAverage<TValue>::Reset()
+{
+    while (!Values_.empty()) {
+        Values_.pop();
+    }
+
+    Total_ = {};
+}
+
+template <class TValue>
+void TMovingAverage<TValue>::RemoveOldValues()
+{
+    while (std::ssize(Values_) > WindowSize_) {
+        Total_ -= Values_.front();
+        Values_.pop();
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
diff --git a/yt/yt/core/misc/moving_average.h b/yt/yt/core/misc/moving_average.h
new file mode 100644
index 00000000000..f32e34a153c
--- /dev/null
+++ b/yt/yt/core/misc/moving_average.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include "public.h"
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class TValue>
+class TMovingAverage
+{
+public:
+    TMovingAverage() = default;
+    explicit TMovingAverage(int windowSize);
+
+    void AddValue(TValue value);
+
+    std::optional<TValue> GetAverage() const;
+
+    void SetWindowSize(int windowSize);
+
+    void Reset();
+
+private:
+    int WindowSize_ = 0;
+    std::queue<TValue> Values_;
+    TValue Total_{};
+
+    void RemoveOldValues();
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
+
+#define MOVING_AVERAGE_INL_H_
+#include "moving_average-inl.h"
+#undef MOVING_AVERAGE_INL_H_
diff --git a/yt/yt/core/misc/unittests/moving_average_ut.cpp b/yt/yt/core/misc/unittests/moving_average_ut.cpp
new file mode 100644
index 00000000000..8c2c8713586
--- /dev/null
+++ b/yt/yt/core/misc/unittests/moving_average_ut.cpp
@@ -0,0 +1,70 @@
+#include <yt/yt/core/test_framework/framework.h>
+
+#include <yt/yt/core/misc/moving_average.h>
+
+namespace NYT {
+namespace {
+
+////////////////////////////////////////////////////////////////////////////////
+
+TEST(TMovingAverageTest, Empty)
+{
+    TMovingAverage<int> movingAverage;
+    EXPECT_FALSE(movingAverage.GetAverage());
+
+    movingAverage.AddValue(0);
+    EXPECT_FALSE(movingAverage.GetAverage());
+}
+
+TEST(TMovingAverageTest, Reset)
+{
+    TMovingAverage<int> movingAverage(3);
+    EXPECT_FALSE(movingAverage.GetAverage());
+
+    movingAverage.AddValue(0);
+    movingAverage.AddValue(1);
+    movingAverage.AddValue(2);
+    EXPECT_EQ(1, movingAverage.GetAverage());
+
+    movingAverage.Reset();
+    EXPECT_FALSE(movingAverage.GetAverage());
+}
+
+TEST(TMovingAverageTest, SimpleInt)
+{
+    TMovingAverage<int> movingAverage(3);
+    EXPECT_FALSE(movingAverage.GetAverage());
+
+    movingAverage.AddValue(0);
+    movingAverage.AddValue(1);
+    for (int i = 1; i < 10; ++i) {
+        movingAverage.AddValue(i + 1);
+        EXPECT_EQ(i, movingAverage.GetAverage());
+    }
+
+    movingAverage.SetWindowSize(1);
+    EXPECT_EQ(10, movingAverage.GetAverage());
+
+    movingAverage.SetWindowSize(2);
+    EXPECT_EQ(10, movingAverage.GetAverage());
+
+    movingAverage.AddValue(20);
+    movingAverage.AddValue(30);
+    EXPECT_EQ(25, movingAverage.GetAverage());
+}
+
+TEST(TMovingAverageTest, SimpleDouble)
+{
+    TMovingAverage<double> movingAverage(100);
+    EXPECT_FALSE(movingAverage.GetAverage());
+
+    for (int i = 0; i < 1000; ++i) {
+        movingAverage.AddValue(i);
+    }
+    EXPECT_EQ(949.5, movingAverage.GetAverage());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace
+} // namespace NYT
diff --git a/yt/yt/core/misc/unittests/ya.make b/yt/yt/core/misc/unittests/ya.make
index 0de99de730d..fae325df753 100644
--- a/yt/yt/core/misc/unittests/ya.make
+++ b/yt/yt/core/misc/unittests/ya.make
@@ -45,6 +45,7 @@ SRCS(
     lru_cache_ut.cpp
     maybe_inf_ut.cpp
     memory_tag_ut.cpp
+    moving_average_ut.cpp
     mpsc_fair_share_queue_ut.cpp
     mpsc_stack_ut.cpp
     mpsc_queue_ut.cpp