diff --git a/sources/lib/common/stats.go b/sources/lib/common/stats.go
new file mode 100644
index 0000000..d2e5a3f
--- /dev/null
+++ b/sources/lib/common/stats.go
@@ -0,0 +1,283 @@
+
+
+package common
+
+
+import "math"
+import "sync/atomic"
+
+
+
+
+type StatMetric struct {
+	
+	MetricSource *uint64
+	DividerSource *uint64
+	
+	ValueDelta bool
+	SpeedDelta bool
+	
+	ValueThreshold float64
+	SpeedThreshold float64
+	
+	MetricScale float64
+	DividerScale float64
+	ValueScale float64
+	SpeedScale float64
+	
+	Changed bool
+	Invalid bool
+	
+	metricLast_0 uint64
+	dividerLast_0 uint64
+	
+	MetricLast float64
+	DividerLast float64
+	ValueLast float64
+	speed0Last float64
+	
+	TimeDelta uint64
+	TimeLast uint64
+	TimeFirst uint64
+	TimeChanged uint64
+	CountChanged uint64
+	
+	Speed1Last float64
+	Speed1Window float64
+	Speed1pLast float64
+	Speed1paLast float64
+	Speed1prLast float64
+	Speed1pWindow float64
+	Speed1paWindow float64
+	Speed1prWindow float64
+	
+	Speed2Last float64
+	Speed2Window float64
+	Speed2pLast float64
+	Speed2paLast float64
+	Speed2prLast float64
+	Speed2pWindow float64
+	Speed2paWindow float64
+	Speed2prWindow float64
+	
+	WindowSize uint64
+}
+
+
+
+
+func (_stat *StatMetric) Update2 (_timeNanoseconds uint64, _changed *bool, _invalid *bool) () {
+	_stat.Update (_timeNanoseconds)
+	*_changed = *_changed || _stat.Changed
+	*_invalid = *_invalid || _stat.Invalid
+}
+
+
+
+
+func (_stat *StatMetric) Update (_timeNanoseconds uint64) () {
+	
+	_invalid := false
+	
+	_timeNow := _timeNanoseconds
+	
+	_metricNow_0 := atomic.LoadUint64 (_stat.MetricSource)
+	_metricNow := float64 (_metricNow_0)
+	if _stat.MetricScale != 0 {
+		_metricNow = _metricNow / _stat.MetricScale
+	}
+	
+	_dividerNow_0 := uint64 (0)
+	if _stat.DividerSource != nil {
+		_dividerNow_0 = atomic.LoadUint64 (_stat.DividerSource)
+	}
+	_dividerNow := float64 (_dividerNow_0)
+	if _stat.DividerScale != 0 {
+		_dividerNow = _dividerNow / _stat.DividerScale
+	}
+	
+	_timeDelta := int64 (_timeNow) - int64 (_stat.TimeLast)
+	_timeDeltaSec := float64 (_timeDelta) / 1000000000
+	
+	if _timeDelta <= 0 {
+		_invalid = true
+	}
+	
+	_valueNow := _metricNow
+	_speed0Now := _metricNow
+	
+	if _stat.ValueDelta {
+		_valueNow = _valueNow - _stat.MetricLast
+	}
+	if _stat.SpeedDelta {
+		_speed0Now = _speed0Now - _stat.MetricLast
+	}
+	
+	if _stat.DividerSource != nil {
+		
+		if _stat.ValueDelta {
+			_dividerDelta := _dividerNow - _stat.DividerLast
+			if _dividerDelta > 0 {
+				_valueNow = _valueNow / _dividerDelta
+			} else {
+				_invalid = true
+			}
+		} else {
+			if _dividerNow > 0 {
+				_valueNow = _valueNow / _dividerNow
+			} else {
+				_invalid = true
+			}
+		}
+		
+		if _stat.SpeedDelta {
+			_dividerDelta := _dividerNow - _stat.DividerLast
+			if _dividerDelta > 0 {
+				_speed0Now = _speed0Now / _dividerDelta
+			} else {
+				_invalid = true
+			}
+		} else {
+			if _dividerNow > 0 {
+				_speed0Now = _speed0Now / _dividerNow
+			} else {
+				_invalid = true
+			}
+		}
+	}
+	
+	if _stat.ValueScale != 0 {
+		_valueNow = _valueNow / _stat.ValueScale
+	}
+	if _stat.SpeedScale != 0 {
+		_speed0Now = _speed0Now / _stat.SpeedScale
+	}
+	
+	if _stat.CountChanged == 0 {
+		_stat.TimeFirst = _timeNow
+		_invalid = true
+	}
+	
+	_stat.Changed = false
+	_thresholdUsed := false
+	_thresholdMatched := false
+	
+	if _invalid {
+		goto _return
+	}
+	
+	_stat.Changed = (_stat.metricLast_0 != _metricNow_0) || (_stat.dividerLast_0 != _dividerNow_0)
+	
+	if _stat.Changed {
+		
+		_speed1Now := (_speed0Now - _stat.speed0Last) / _timeDeltaSec
+		_speed1pNow := _speed1Now / _stat.Speed1Last - 1
+		
+		_speed2Now := (_speed1Now - _stat.Speed1Last) / _timeDeltaSec
+		_speed2pNow := _speed2Now / _stat.Speed2Last - 1
+		
+		_stat.Speed1Last = _speed1Now
+		_stat.Speed2Last = _speed2Now
+		
+		_windowNew := float64 (0)
+		const _windowSizeNormal = 12
+		if _stat.WindowSize >= _windowSizeNormal {
+			_windowNew = 1 / float64 (_windowSizeNormal + 1)
+		} else {
+			_windowNew = 1 / float64 (_stat.WindowSize + 1)
+		}
+		_windowOld := 1 - _windowNew
+		
+		if ((_timeNow - _stat.TimeChanged) / 1000000000 > 6) || (_stat.TimeChanged == 0) || (_stat.WindowSize == 0) {
+			_stat.Speed1pLast = 0
+			_stat.Speed1Window = _speed1Now
+			_stat.Speed1pWindow = 0
+			_stat.Speed2pLast = 0
+			_stat.Speed2Window = _speed2Now
+			_stat.Speed2pWindow = 0
+		} else {
+			_stat.Speed1pLast = _speed1pNow
+			_stat.Speed1Window = _stat.Speed1Window * _windowOld + _speed1Now * _windowNew
+			_stat.Speed1pWindow = _stat.Speed1pWindow * _windowOld + _speed1pNow * _windowNew
+			_stat.Speed2pLast = _speed2pNow
+			_stat.Speed2Window = _stat.Speed2Window * _windowOld + _speed2Now * _windowNew
+			_stat.Speed2pWindow = _stat.Speed2pWindow * _windowOld + _speed2pNow * _windowNew
+		}
+		
+		_stat.TimeChanged = _timeNow
+		_stat.WindowSize++
+		
+	} else {
+		
+		if ((_timeNow - _stat.TimeChanged) / 1000000000 > 6) || (_stat.TimeChanged == 0) {
+			_stat.Speed1Last = 0.0
+			_stat.Speed1Window = 0.0
+			_stat.Speed1pWindow = 0.0
+			_stat.Speed1pLast = 0.0
+			_stat.Speed1paLast = 0.0
+			_stat.Speed2Last = 0.0
+			_stat.Speed2Window = 0.0
+			_stat.Speed2pWindow = 0.0
+			_stat.Speed2pLast = 0.0
+			_stat.Speed2paLast = 0.0
+			_stat.WindowSize = 0
+		}
+	}
+	
+	if _stat.ValueThreshold != 0 {
+		_thresholdUsed = true
+		_thresholdMatched = _thresholdMatched || (math.Abs (_valueNow) >= _stat.ValueThreshold)
+	}
+	if _stat.SpeedThreshold != 0 {
+		_thresholdUsed = true
+		_thresholdMatched = _thresholdMatched || (math.Abs (_stat.Speed1Last) >= _stat.SpeedThreshold)
+	}
+	if _thresholdUsed && !_thresholdMatched {
+		_stat.Changed = false
+	}
+	
+	_return :
+	
+	_stat.metricLast_0 = _metricNow_0
+	_stat.dividerLast_0 = _dividerNow_0
+	
+	_stat.MetricLast = _metricNow
+	_stat.DividerLast = _dividerNow
+	
+	_stat.ValueLast = _valueNow
+	_stat.speed0Last = _speed0Now
+	
+	_stat.TimeLast = _timeNow
+	_stat.TimeDelta = uint64 (_timeDelta)
+	
+	_stat.CountChanged += 1
+	
+	_stat.Invalid = _invalid
+	
+	
+	_stat.Speed1paLast = math.Abs (_stat.Speed1pLast)
+	_stat.Speed1paWindow = math.Abs (_stat.Speed1pWindow)
+	_stat.Speed2paLast = math.Abs (_stat.Speed2pLast)
+	_stat.Speed1paWindow = math.Abs (_stat.Speed1paWindow)
+	
+	_stat.Speed1prLast = math.Round (_stat.Speed1pLast * 100 * 100) / 100
+	_stat.Speed1prWindow = math.Round (_stat.Speed1pWindow * 100 * 100) / 100
+	_stat.Speed2prLast = math.Round (_stat.Speed2pLast * 100 * 100) / 100
+	_stat.Speed1prWindow = math.Round (_stat.Speed1paWindow * 100 * 100) / 100
+	
+	_infinite := float64 (1.0)
+	_infinite = _infinite / 0
+	if _stat.Speed1paLast > 1000 {
+		_stat.Speed1prLast = math.Copysign (_infinite, _stat.Speed1prLast)
+	}
+	if _stat.Speed1paWindow > 1000 {
+		_stat.Speed1prWindow = math.Copysign (_infinite, _stat.Speed1prWindow)
+	}
+	if _stat.Speed2paLast > 1000 {
+		_stat.Speed2prLast = math.Copysign (_infinite, _stat.Speed2prLast)
+	}
+	if _stat.Speed2paWindow > 1000 {
+		_stat.Speed2prWindow = math.Copysign (_infinite, _stat.Speed2prWindow)
+	}
+}
+