initial code repo

[stor4nfv.git] / src / ceph / src / dmclock / support / src / profile.h

diff --git a/src/ceph/src/dmclock/support/src/profile.h b/src/ceph/src/dmclock/support/src/profile.h
new file mode 100644 (file)
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--- /dev/null
+++ b/src/ceph/src/dmclock/support/src/profile.h
@@ -0,0 +1,114 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+/*
+ * Copyright (C) 2016 Red Hat Inc.
+ */
+
+
+#pragma once
+
+
+#include <cmath>
+#include <chrono>
+
+
+namespace crimson {
+  template<typename T>
+  class ProfileBase {
+
+  protected:
+
+    using clock = std::chrono::steady_clock;
+
+    uint count = 0;
+    typename T::rep sum = 0;
+    typename T::rep sum_squares = 0;
+    typename T::rep low = 0;
+    typename T::rep high = 0;
+
+  public:
+
+    uint get_count() const { return count; }
+    typename T::rep get_sum() const { return sum; }
+    typename T::rep get_low() const { return low; }
+    typename T::rep get_high() const { return high; }
+    double get_mean() const {
+      if (0 == count) return nan("");
+      return sum / double(count); }
+    double get_std_dev() const {
+      if (0 == count) return nan("");
+      double variance =
+       (count * sum_squares - sum * sum) / double(count * count);
+      return sqrt(variance);
+    }
+  }; // class ProfileBase
+
+
+  // forward declaration for friend
+  template<typename T>
+  class ProfileCombiner;
+
+
+  template<typename T>
+  class ProfileTimer : public ProfileBase<T> {
+    friend ProfileCombiner<T>;
+
+    using super = ProfileBase<T>;
+
+    bool is_timing = false;
+    typename super::clock::time_point start_time;
+
+  public:
+
+    ProfileTimer() {
+    }
+
+    void start() {
+      assert(!is_timing);
+      start_time = super::clock::now();
+      is_timing = true;
+    }
+
+    void stop() {
+      assert(is_timing);
+      T duration = std::chrono::duration_cast<T>(super::clock::now() - start_time);
+      typename T::rep duration_count = duration.count();
+      this->sum += duration_count;
+      this->sum_squares += duration_count * duration_count;
+      if (0 == this->count) {
+       this->low = duration_count;
+       this->high = duration_count;
+      } else {
+       if (duration_count < this->low) this->low = duration_count;
+       else if (duration_count > this->high) this->high = duration_count;
+      }
+      ++this->count;
+      is_timing = false;
+    }
+  };  // class ProfileTimer
+
+
+  template<typename T>
+  class ProfileCombiner : public ProfileBase<T> {
+
+    using super = ProfileBase<T>;
+
+  public:
+
+    ProfileCombiner() {}
+
+    void combine(const ProfileTimer<T>& timer) {
+      if (0 == this->count) {
+       this->low = timer.low;
+       this->high = timer.high;
+      } else {
+       if (timer.low < this->low) this->low = timer.low;
+       else if (timer.high > this->high) this->high = timer.high;
+      }
+      this->count += timer.count;
+      this->sum += timer.sum;
+      this->sum_squares += timer.sum_squares;
+    }
+  }; // class ProfileCombiner
+} // namespace crimson