intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 71 insertions, 0 deletions

diff --git a/library/cpp/monlib/metrics/log_histogram_snapshot.h b/library/cpp/monlib/metrics/log_histogram_snapshot.h
new file mode 100644
index 0000000000..7673b43751
--- /dev/null
+++ b/library/cpp/monlib/metrics/log_histogram_snapshot.h
@@ -0,0 +1,71 @@
+#pragma once
+
+#include <util/generic/ptr.h>
+#include <util/generic/vector.h>
+
+#include <cmath>
+
+namespace NMonitoring {
+
+    constexpr ui32 LOG_HIST_MAX_BUCKETS = 100;
+
+    class TLogHistogramSnapshot: public TAtomicRefCount<TLogHistogramSnapshot> {
+    public:
+        TLogHistogramSnapshot(double base, ui64 zerosCount, int startPower, TVector<double> buckets)
+            : Base_(base)
+            , ZerosCount_(zerosCount)
+            , StartPower_(startPower)
+            , Buckets_(std::move(buckets)) {
+        }
+
+        /**
+         * @return buckets count.
+         */
+        ui32 Count() const noexcept {
+            return Buckets_.size();
+        }
+
+        /**
+         * @return upper bound for the bucket with particular index.
+         */
+        double UpperBound(int index) const noexcept {
+            return std::pow(Base_, StartPower_ + index);
+        }
+
+        /**
+         * @return value stored in the bucket with particular index.
+         */
+        double Bucket(ui32 index) const noexcept {
+            return Buckets_[index];
+        }
+
+        /**
+         * @return nonpositive values count
+         */
+        ui64 ZerosCount() const noexcept {
+            return ZerosCount_;
+        }
+
+        double Base() const noexcept {
+            return Base_;
+        }
+
+        int StartPower() const noexcept {
+            return StartPower_;
+        }
+
+        ui64 MemorySizeBytes() const noexcept {
+            return sizeof(*this) + Buckets_.capacity() * sizeof(double);
+        }
+
+    private:
+        double Base_;
+        ui64 ZerosCount_;
+        int StartPower_;
+        TVector<double> Buckets_;
+    };
+
+    using TLogHistogramSnapshotPtr = TIntrusivePtr<TLogHistogramSnapshot>;
+}
+
+std::ostream& operator<<(std::ostream& os, const NMonitoring::TLogHistogramSnapshot& hist);