/// <summary>
/// Create a new event metric object from the provided raw data packet
/// </summary>
/// <remarks>The new metric will automatically be added to the metric definition's metrics collection.</remarks>
/// <param name="definition">The object that defines this metric</param>
/// <param name="packet">The raw data packet</param>
internal EventMetric(EventMetricDefinition definition, EventMetricPacket packet)
: base(definition, packet)
{
// We created an EventMetricSampleCollection when base constructor called our OnSampleCollectionCreate().
m_Samples = (EventMetricSampleCollection)base.Samples;
m_MetricDefinition = definition;
m_Packet = packet;
}
/// <summary>
/// Compute the resultant value for this sample compared with the provided baseline sample.
/// </summary>
/// <remarks>
/// <para>The baseline sample must be for a date and time prior to this sample for correct results.</para>
/// <para>If the supplied trendValue isn't trendable, the number of samples with a non-null value will be counted.</para>
/// <para>If the supplied trendValue is trendable, the Default Trend (average or sum) will be calculated for all
/// samples between the supplied baseline sample and this sample, inclusive.</para>
/// </remarks>
/// <param name="baselineSample">The previous baseline sample to calculate a difference for</param>
/// <param name="trendValue">The definition of the value from this event metric to trend.</param>
/// <returns>The calculated counter value</returns>
public double ComputeValue(IEventMetricSample baselineSample, IEventMetricValueDefinition trendValue)
{
//we have to figure out all of the samples to include between these points.
List <EventMetricSample> valueSamples = new List <EventMetricSample>();
EventMetricSampleCollection samples = Metric.Samples;
int startIndex = (baselineSample == null) ? 0 : samples.IndexOf(baselineSample);
int ourIndex = samples.IndexOf(this);
for (int sampleIndex = startIndex; sampleIndex <= ourIndex; sampleIndex++)
{
valueSamples.Add(samples[sampleIndex]);
}
return(Metric.CalculateSample(null, valueSamples, 0, 0, Timestamp, (EventMetricValueDefinition)trendValue));
}
