// Will aggregate metrics for a single tag of a single template
IEnumerable <Metric> AggregateTag(IEnumerable <Metric> metrics, IEnumerable <string> targetMetricNames, string targetTag, IAggregator aggregator)
{
var aggregateValues = new DefaultDictionary <AggregateMetric, IAggregator>(_ => aggregator.New());
foreach (Metric metric in metrics)
{
// if metric is the aggregation target and it has a tag that should be aggregated
if (targetMetricNames.Contains(metric.Name) && metric.Tags.ContainsKey(targetTag))
{
var aggregateMetric = new AggregateMetric(metric, targetTag);
aggregateValues[aggregateMetric].PutValue(metric.Value);
}
else
{
yield return(metric);
}
}
// aggregate all and construct new metrics from result
foreach (var aggregatePair in aggregateValues)
{
double aggregatedValue = aggregatePair.Value.GetAggregate();
yield return(aggregatePair.Key.ToMetric(aggregatedValue));
}
}
