/// <summary>
/// Creates the file listener.
/// </summary>
/// <param name="providerGuid">The provider unique identifier.</param>
/// <param name="etlFileName">Name of the etl file.</param>
/// <param name="metricProducedAction">The metric produced action.</param>
/// <param name="eventIdFilter">The event identifier filter.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>A <see cref="RawListener"/> instance.</returns>
private static RawListener CreateFileListener(
Guid providerGuid,
string etlFileName,
Action <ILocalAggregatedMetric> metricProducedAction,
int eventIdFilter,
CancellationToken cancellationToken)
{
return(RawListener.CreateEtlFileListener(
new[] { etlFileName },
eventRecord =>
{
if (eventRecord->EventHeader.ProviderId == providerGuid && eventRecord->EventHeader.Id == eventIdFilter)
{
metricProducedAction(LocalAggregatedMetric.ConvertToMetricData(eventRecord));
}
},
eventTraceLog =>
{
Logger.Log(
LoggerLevel.Info,
LogId,
"CreateFileListener",
"LocalAggregatedMetric, cancelled = {0}",
cancellationToken.IsCancellationRequested);
return !cancellationToken.IsCancellationRequested;
}));
}
/// <summary>
/// Converts content of the ETW event published by ME to a <see cref="LocalAggregatedMetric"/>
/// </summary>
/// <param name="etwMetricData">Object containing information about metric data sample.</param>
/// <returns>A MetricData object representing a locally aggregated metric.</returns>
internal static unsafe LocalAggregatedMetric ConvertToMetricData(NativeMethods.EventRecord *etwMetricData)
{
var metricData = new LocalAggregatedMetric();
IntPtr pointerInPayload = etwMetricData->UserData;
metricData.MonitoringAccount = EtwPayloadManipulationUtils.ReadString(ref pointerInPayload);
metricData.MetricNamespace = EtwPayloadManipulationUtils.ReadString(ref pointerInPayload);
metricData.MetricName = EtwPayloadManipulationUtils.ReadString(ref pointerInPayload);
long timestamp = *((long *)pointerInPayload);
metricData.MetricTimeUtc = DateTime.FromFileTimeUtc(timestamp);
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(long));
// Read the dimension name and values and split them out.
var dimensionNames = EtwPayloadManipulationUtils.ReadString(ref pointerInPayload);
var dimensionValues = EtwPayloadManipulationUtils.ReadString(ref pointerInPayload);
if (!string.IsNullOrWhiteSpace(dimensionNames) && !string.IsNullOrWhiteSpace(dimensionValues))
{
var splitDimensionNames = dimensionNames.Split(EtwListSeparatorChar, StringSplitOptions.None);
var splitDimensionValues = dimensionValues.Split(EtwListSeparatorChar, StringSplitOptions.None);
// Expected that both lengths be the same since they are written this way.
for (var x = 0; x < splitDimensionNames.Length && x < splitDimensionValues.Length; ++x)
{
metricData.dimensions[splitDimensionNames[x]] = splitDimensionValues[x];
}
}
var scalingFactor = *((float *)pointerInPayload);
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(float));
metricData.ScalingFactor = scalingFactor;
var samplingTypes = (SamplingTypes)(*((int *)pointerInPayload));
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(int));
if ((samplingTypes & SamplingTypes.Min) != 0)
{
metricData.Min = *((ulong *)pointerInPayload);
metricData.ScaledMin = metricData.Min / scalingFactor;
}
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(ulong));
if ((samplingTypes & SamplingTypes.Max) != 0)
{
metricData.Max = *((ulong *)pointerInPayload);
metricData.ScaledMax = metricData.Max / scalingFactor;
}
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(ulong));
if ((samplingTypes & SamplingTypes.Sum) != 0)
{
metricData.Sum = *((ulong *)pointerInPayload);
metricData.ScaledSum = metricData.Sum / scalingFactor;
}
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(ulong));
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(float));
if ((samplingTypes & SamplingTypes.Count) != 0)
{
metricData.Count = *((uint *)pointerInPayload);
}
pointerInPayload = EtwPayloadManipulationUtils.Shift(pointerInPayload, sizeof(uint));
return(metricData);
}
