intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 45 insertions, 0 deletions

diff --git a/library/cpp/messagebus/duration_histogram.h b/library/cpp/messagebus/duration_histogram.h
new file mode 100644
index 0000000000..ed060b0101
--- /dev/null
+++ b/library/cpp/messagebus/duration_histogram.h
@@ -0,0 +1,45 @@
+#pragma once
+
+#include <util/datetime/base.h>
+#include <util/generic/bitops.h>
+#include <util/generic/string.h>
+
+#include <array>
+
+struct TDurationHistogram {
+    static const unsigned Buckets = 20;
+    std::array<ui64, Buckets> Times;
+
+    static const unsigned SecondBoundary = 11;
+
+    TDurationHistogram() {
+        Times.fill(0);
+    }
+
+    static unsigned BucketFor(TDuration d) {
+        ui64 units = d.MicroSeconds() * (1 << SecondBoundary) / 1000000;
+        if (units == 0) {
+            return 0;
+        }
+        unsigned bucket = GetValueBitCount(units) - 1;
+        if (bucket >= Buckets) {
+            bucket = Buckets - 1;
+        }
+        return bucket;
+    }
+
+    void AddTime(TDuration d) {
+        Times[BucketFor(d)] += 1;
+    }
+
+    TDurationHistogram& operator+=(const TDurationHistogram& that) {
+        for (unsigned i = 0; i < Times.size(); ++i) {
+            Times[i] += that.Times[i];
+        }
+        return *this;
+    }
+
+    static TString LabelBefore(unsigned i);
+
+    TString PrintToString() const;
+};