private void ReadMetricsData(
BinaryReader reader,
IFrontEndMetricBuilder <TMetadata> metricBuilder,
ushort version,
int maxMetricDimensionValueStringsLength)
{
long packetTime = 0;
if (version >= 5)
{
packetTime = (long)SerializationUtils.ReadUInt64FromBase128(reader);
}
Stream readerStream = reader.BaseStream;
var metricsCount = reader.ReadUInt32();
for (var i = 0; i < metricsCount; ++i)
{
DateTime timeUtc;
var count = 0U;
var sum = default(MetricValueV2);
var min = default(MetricValueV2);
var max = default(MetricValueV2);
double sumOfSquareDiffFromMean = 0;
var metadata = this.ReadMetricMetadataByIndex(reader);
if (version >= 5)
{
var timeInTicks = (packetTime - SerializationUtils.ReadInt64FromBase128(reader)) * SerializationUtils.OneMinuteInterval;
timeUtc = new DateTime(timeInTicks, DateTimeKind.Utc);
}
else
{
timeUtc = new DateTime((long)SerializationUtils.ReadUInt64FromBase128(reader), DateTimeKind.Utc);
}
for (var j = 0; j < metadata.DimensionsCount; ++j)
{
var dimensionValue = this.ReadStringByIndex(reader);
if (dimensionValue.Length > maxMetricDimensionValueStringsLength)
{
throw new MetricSerializationException($"Dimension value string in the packet exceeds preconfigured length. Packet is corrupted. MaxLength:{maxMetricDimensionValueStringsLength}, Value:{dimensionValue}.", null, true);
}
this.reusableStringsList.Add(dimensionValue);
}
var samplingTypes = (SamplingTypes)SerializationUtils.ReadUInt32FromBase128(reader);
var isDouble = (samplingTypes & SamplingTypes.DoubleValueType) != 0;
var isDoubleStoredAslong = (samplingTypes & SamplingTypes.DoubleValueStoredAsLongType) != 0;
if ((samplingTypes & SamplingTypes.Min) != 0)
{
min = this.ReadMetricValue(reader, isDouble, isDoubleStoredAslong);
}
if ((samplingTypes & SamplingTypes.Max) != 0)
{
max = this.ReadMetricValue(reader, isDouble, isDoubleStoredAslong);
}
if ((samplingTypes & SamplingTypes.Sum) != 0)
{
sum = this.ReadMetricValue(reader, isDouble, isDoubleStoredAslong);
}
if ((samplingTypes & SamplingTypes.Count) != 0)
{
count = SerializationUtils.ReadUInt32FromBase128(reader);
}
if ((samplingTypes & SamplingTypes.SumOfSquareDiffFromMean) != 0)
{
sumOfSquareDiffFromMean = reader.ReadDouble();
}
bool haveHistogram = (samplingTypes & SamplingTypes.Histogram) != 0;
metricBuilder.BeginMetricCreation(metadata, this.reusableStringsList, timeUtc, samplingTypes, count, sum, min, max, sumOfSquareDiffFromMean);
this.reusableStringsList.Clear();
if (haveHistogram)
{
IEnumerable <KeyValuePair <ulong, uint> > histogramBuckets =
SerializationUtils.ReadHistogram(reader, hasHistogramSizePrefix: version > 3);
this.histogramBuffer.Clear();
this.histogramBuffer.AddRange(histogramBuckets);
metricBuilder.AssignHistogram(this.histogramBuffer);
}
if ((samplingTypes & SamplingTypes.HyperLogLogSketch) != 0)
{
var sizeOfHyperLogLogSketches = reader.ReadInt32();
metricBuilder.AssignHyperLogLogSketch(reader, sizeOfHyperLogLogSketches);
}
if (version >= 6)
{
bool haveTDigest = (samplingTypes & SamplingTypes.TDigest) != 0;
bool readTDigest = false;
// starting from version 6, there is a list of TLV-type
// (https://en.wikipedia.org/wiki/Type-length-value) tuples in the rest of the serialized metric.
// deserialize all of them ignoring the unknown ones.
// list TLV values is expected to contain a single end-of-list marker in the end with T = 0x00
uint type;
while ((type = SerializationUtils.ReadUInt32FromBase128(reader)) != 0x00)
{
int length = (int)SerializationUtils.ReadUInt32FromBase128(reader);
long nextPos = readerStream.Position + length;
switch (type)
{
case TDigestPrefixValue: // 0x74 == 't' (tDigest)
if (haveTDigest)
{
if (!readTDigest)
{
metricBuilder.AssignTDigest(reader, length);
readTDigest = true;
}
else
{
// if we already saw tDigest value and see it
// second time it is a sign of a protocol error.
throw new MetricSerializationException("Saw 2 TDigest values for the same metric", null, isInvalidData: true);
}
}
else
{
// if TLV list contains tDigest but the sampling types does not
// it is a protocol error
throw new MetricSerializationException("Sampling types do not contain tDigest, but TLV list contains it", null, isInvalidData: true);
}
break;
default:
// ignore unknown types
break;
}
// always set the position to point to the next entry.
// do not trust the deserializer code to leave the position set correctly
// this helps prevent compatibility problems and makes the deserializer
// more stable
readerStream.Position = nextPos;
}
if (haveTDigest && !readTDigest)
{
// if sampling types contain TDigest but we have not seen it in TLV this is
// a sign of protocol error
throw new MetricSerializationException("Sampling types contain tDigest, but TLV list does not contain it", null, isInvalidData: true);
}
}
metricBuilder.EndMetricCreation();
}
}