public SpanContext Extract <T>(T carrier, Func <T, string, IEnumerable <string> > getter)
{
if (carrier == null)
{
throw new ArgumentNullException(nameof(carrier));
}
if (getter == null)
{
throw new ArgumentNullException(nameof(getter));
}
var traceId = PropagationHelpers.ParseTraceId(carrier, getter, B3HttpHeaderNames.B3TraceId, Log);
if (traceId == TraceId.Zero)
{
// a valid traceId is required to use distributed tracing
return(null);
}
var spanId = ParseHexUInt64(carrier, getter, B3HttpHeaderNames.B3SpanId);
var samplingPriority = ParseB3Sampling(carrier, getter);
return(new SpanContext(traceId, spanId, samplingPriority));
}
public static string ParseString(this IHeadersCollection headers, string headerName)
{
return(PropagationHelpers.ParseString(headers, (carrier, header) => carrier.GetValues(header), headerName));
}