Merge pull request #4390 from ygorshenin/fix-locality-finder

[search] Fixed locality matching code.

4 files changed, 77 insertions, 2 deletions

diff --git a/base/base.pro b/base/base.pro
index d0976ea2f7..803d1b544a 100644
--- a/base/base.pro
+++ b/base/base.pro
@@ -10,9 +10,9 @@ include($$ROOT_DIR/common.pri)
 SOURCES += \
     base.cpp \
     condition.cpp \
-    gmtime.cpp \
     deferred_task.cpp \
     exception.cpp \
+    gmtime.cpp \
     internal/message.cpp \
     logging.cpp \
     lower_case.cpp \
@@ -28,6 +28,7 @@ SOURCES += \
     thread_checker.cpp \
     thread_pool.cpp \
     threaded_container.cpp \
+    time_samples.cpp \
     timegm.cpp \
     timer.cpp \
 
@@ -81,6 +82,7 @@ HEADERS += \
     threaded_container.hpp \
     threaded_list.hpp \
     threaded_priority_queue.hpp \
+    time_samples.hpp \
     timegm.hpp \
     timer.hpp \
     worker_thread.hpp \
diff --git a/base/time_samples.cpp b/base/time_samples.cpp
new file mode 100644
index 0000000000..209385b060
--- /dev/null
+++ b/base/time_samples.cpp
@@ -0,0 +1,24 @@
+#include "base/time_samples.hpp"
+
+#include "std/cmath.hpp"
+
+namespace my
+{
+void TimeSamples::Add(double seconds)
+{
+  m_sum += seconds;
+  m_sum2 += seconds * seconds;
+  ++m_total;
+}
+
+double TimeSamples::GetMean() const { return m_total == 0 ? 0.0 : m_sum / m_total; }
+
+double TimeSamples::GetSD() const
+{
+  if (m_total < 2)
+    return 0.0;
+  return std::max((m_sum2 - m_sum * m_sum / static_cast<double>(m_total)) / (m_total - 1), 0.0);
+}
+
+double TimeSamples::GetVar() const { return sqrt(GetSD()); }
+}  // namespace my
diff --git a/base/time_samples.hpp b/base/time_samples.hpp
new file mode 100644
index 0000000000..c4f1fdf072
--- /dev/null
+++ b/base/time_samples.hpp
@@ -0,0 +1,49 @@
+#pragma once
+
+#include "base/timer.hpp"
+
+#include "std/cstdint.hpp"
+
+namespace my
+{
+// This class can be used in measurements of code blocks performance.
+// It can accumulate time samples, and can calculate mean time and
+// standard deviation.
+//
+// *NOTE* This class is NOT thread-safe.
+class TimeSamples final
+{
+public:
+  void Add(double seconds);
+
+  // Mean of the accumulated time samples.
+  double GetMean() const;
+
+  // Unbiased standard deviation of the accumulated time samples.
+  double GetSD() const;
+
+  // Unbiased variance of the accumulated time samples.
+  double GetVar() const;
+
+private:
+  double m_sum = 0.0;
+  double m_sum2 = 0.0;
+  size_t m_total = 0;
+};
+
+// This class can be used as a single scoped time sample. It
+// automatically adds time sample on destruction.
+//
+// *NOTE* This class is NOT thread-safe.
+class ScopedTimeSample final
+{
+public:
+  ScopedTimeSample(TimeSamples & ts) : m_ts(ts) {}
+  ~ScopedTimeSample() { m_ts.Add(m_t.ElapsedSeconds()); }
+
+private:
+  TimeSamples & m_ts;
+  my::Timer m_t;
+};
+
+}  // namespace my
diff --git a/base/timer.hpp b/base/timer.hpp
index bd793f92c1..d64c66a0ac 100644
--- a/base/timer.hpp
+++ b/base/timer.hpp
@@ -73,4 +73,4 @@ public:
 
 time_t SecondsSinceEpochToTimeT(uint64_t secondsSinceEpoch);
 uint64_t TimeTToSecondsSinceEpoch(time_t time);
-}
+}  // namespace my