/// <summary>
/// Creates a new histogram metric with tags.
/// </summary>
/// <param name="metricsCollector">The metrics collector being extended.</param>
/// <param name="name">The name of the metric.</param>
/// <param name="description">The description of the metric.</param>
/// <param name="buckets">The upper bounds of the buckets to aggregate into in ascending order, a bucket with value <see cref="double.PositiveInfinity"/> will be automattically added if omitted.</param>
/// <param name="tags">The tags to attach to the metric in the form "key:value".</param>
/// <returns>The created histogram.</returns>
public static TaggedMetricBuilder <IHistogramMetric> Histogram(this MetricsCollector metricsCollector, string name, string description, double[] buckets, params string[] tags)
{
if (!metricsCollector.IsWritingToPrometheus())
{
throw new InvalidOperationException("Prometheus metrics extensions cannot be used without a non-prometheus metric writer. Consider using core metric types, exensions for your chosen writer or switch to the Promethus metrics writer.");
}
ValidateTags(tags);
// Ensure buckets always get larger
double lastBucket = double.NegativeInfinity;
foreach (double bucket in buckets)
{
if (lastBucket >= bucket)
{
throw new ArgumentException("Buckets must be in ascending order and not start at double.NegativeInfinity.");
}
lastBucket = bucket;
}
// Ensure the last bucket upper bound is always infinity
if (buckets.Length == 0 || buckets[buckets.Length - 1] != double.PositiveInfinity)
{
Array.Resize(ref buckets, buckets.Length + 1);
buckets[buckets.Length - 1] = double.PositiveInfinity;
}
return(((PrometheusEndpoint)metricsCollector.Writer).CreateHistogram(metricsCollector, name, description, tags));
}
