1 files changed, 136 insertions, 10 deletions

diff --git a/indra/llcommon/lltraceaccumulators.cpp b/indra/llcommon/lltraceaccumulators.cpp
index 950c1d97d1..a632f5634c 100644
--- a/indra/llcommon/lltraceaccumulators.cpp
+++ b/indra/llcommon/lltraceaccumulators.cpp
@@ -86,21 +86,21 @@ bool AccumulatorBufferGroup::isPrimary() const
 
 void AccumulatorBufferGroup::append( const AccumulatorBufferGroup& other )
 {
-	mCounts.addSamples(other.mCounts);
-	mSamples.addSamples(other.mSamples);
-	mEvents.addSamples(other.mEvents);
-	mMemStats.addSamples(other.mMemStats);
-	mStackTimers.addSamples(other.mStackTimers);
+	mCounts.addSamples(other.mCounts, SEQUENTIAL);
+	mSamples.addSamples(other.mSamples, SEQUENTIAL);
+	mEvents.addSamples(other.mEvents, SEQUENTIAL);
+	mMemStats.addSamples(other.mMemStats, SEQUENTIAL);
+	mStackTimers.addSamples(other.mStackTimers, SEQUENTIAL);
 }
 
 void AccumulatorBufferGroup::merge( const AccumulatorBufferGroup& other)
 {
-	mCounts.addSamples(other.mCounts, false);
-	mSamples.addSamples(other.mSamples, false);
-	mEvents.addSamples(other.mEvents, false);
-	mMemStats.addSamples(other.mMemStats, false);
+	mCounts.addSamples(other.mCounts, NON_SEQUENTIAL);
+	mSamples.addSamples(other.mSamples, NON_SEQUENTIAL);
+	mEvents.addSamples(other.mEvents, NON_SEQUENTIAL);
+	mMemStats.addSamples(other.mMemStats, NON_SEQUENTIAL);
 	// for now, hold out timers from merge, need to be displayed per thread
-	//mStackTimers.addSamples(other.mStackTimers, false);
+	//mStackTimers.addSamples(other.mStackTimers, NON_SEQUENTIAL);
 }
 
 void AccumulatorBufferGroup::reset(AccumulatorBufferGroup* other)
@@ -120,4 +120,130 @@ void AccumulatorBufferGroup::sync()
 	mMemStats.sync(time_stamp);
 }
 
+void SampleAccumulator::addSamples( const SampleAccumulator& other, EBufferAppendType append_type )
+{
+	if (!mHasValue)
+	{
+		*this = other;
+
+		if (append_type == NON_SEQUENTIAL)
+		{
+			// restore own last value state
+			mLastValue = NaN;
+			mHasValue = false;
+		}
+	}
+	else if (other.mHasValue)
+	{
+		mSum += other.mSum;
+
+		if (other.mMin < mMin) { mMin = other.mMin; }
+		if (other.mMax > mMax) { mMax = other.mMax; }
+
+		F64 epsilon = 0.0000001;
+
+		if (other.mTotalSamplingTime > epsilon)
+		{
+			// combine variance (and hence standard deviation) of 2 different sized sample groups using
+			// the following formula: http://www.mrc-bsu.cam.ac.uk/cochrane/handbook/chapter_7/7_7_3_8_combining_groups.htm
+			F64 n_1 = mTotalSamplingTime,
+				n_2 = other.mTotalSamplingTime;
+			F64 m_1 = mMean,
+				m_2 = other.mMean;
+			F64 v_1 = mSumOfSquares / mTotalSamplingTime,
+				v_2 = other.mSumOfSquares / other.mTotalSamplingTime;
+			if (n_1 < epsilon)
+			{
+				mSumOfSquares = other.mSumOfSquares;
+			}
+			else
+			{
+				mSumOfSquares =	mTotalSamplingTime
+					* ((((n_1 - epsilon) * v_1)
+					+ ((n_2 - epsilon) * v_2)
+					+ (((n_1 * n_2) / (n_1 + n_2))
+					* ((m_1 * m_1) + (m_2 * m_2) - (2.f * m_1 * m_2))))
+					/ (n_1 + n_2 - epsilon));
+			}
+
+			llassert(other.mTotalSamplingTime > 0);
+			F64 weight = mTotalSamplingTime / (mTotalSamplingTime + other.mTotalSamplingTime);
+			mNumSamples += other.mNumSamples;
+			mTotalSamplingTime += other.mTotalSamplingTime;
+			mMean = (mMean * weight) + (other.mMean * (1.0 - weight));
+		}
+		if (append_type == SEQUENTIAL)
+		{
+			mLastValue = other.mLastValue;
+			mLastSampleTimeStamp = other.mLastSampleTimeStamp;
+			mHasValue = true;
+		}
+	}
+}
+
+void SampleAccumulator::reset( const SampleAccumulator* other )
+{
+	mLastValue = other ? other->mLastValue : NaN;
+	mHasValue = other ? other->mHasValue : false;
+	mNumSamples = 0;
+	mSum = 0;
+	mMin = mLastValue;
+	mMax = mLastValue;
+	mMean = mLastValue;
+	mSumOfSquares = 0;
+	mLastSampleTimeStamp = LLTimer::getTotalSeconds();
+	mTotalSamplingTime = 0;
+}
+
+void EventAccumulator::addSamples( const EventAccumulator& other, EBufferAppendType append_type )
+{
+	if (other.mNumSamples)
+	{
+		if (!mNumSamples)
+		{
+			*this = other;
+		}
+		else
+		{
+			mSum += other.mSum;
+
+			// NOTE: both conditions will hold first time through
+			if (other.mMin < mMin) { mMin = other.mMin; }
+			if (other.mMax > mMax) { mMax = other.mMax; }
+
+			// combine variance (and hence standard deviation) of 2 different sized sample groups using
+			// the following formula: http://www.mrc-bsu.cam.ac.uk/cochrane/handbook/chapter_7/7_7_3_8_combining_groups.htm
+			F64 n_1 = (F64)mNumSamples,
+				n_2 = (F64)other.mNumSamples;
+			F64 m_1 = mMean,
+				m_2 = other.mMean;
+			F64 v_1 = mSumOfSquares / mNumSamples,
+				v_2 = other.mSumOfSquares / other.mNumSamples;
+			mSumOfSquares = (F64)mNumSamples
+				* ((((n_1 - 1.f) * v_1)
+				+ ((n_2 - 1.f) * v_2)
+				+ (((n_1 * n_2) / (n_1 + n_2))
+				* ((m_1 * m_1) + (m_2 * m_2) - (2.f * m_1 * m_2))))
+				/ (n_1 + n_2 - 1.f));
+
+			F64 weight = (F64)mNumSamples / (F64)(mNumSamples + other.mNumSamples);
+			mNumSamples += other.mNumSamples;
+			mMean = mMean * weight + other.mMean * (1.f - weight);
+			if (append_type == SEQUENTIAL) mLastValue = other.mLastValue;
+		}
+	}
+}
+
+void EventAccumulator::reset( const EventAccumulator* other )
+{
+	mNumSamples = 0;
+	mSum = NaN;
+	mMin = NaN;
+	mMax = NaN;
+	mMean = NaN;
+	mSumOfSquares = 0;
+	mLastValue = other ? other->mLastValue : NaN;
+}
+
+
 }