/// <summary>
/// Extracts a <see cref="SpanContext"/> from the values found in the specified headers.
/// </summary>
/// <param name="carrier">The headers that contain the values to be extracted.</param>
/// <param name="getter">The function that can extract a list of values for a given header name.</param>
/// <typeparam name="T">Type of header collection</typeparam>
/// <returns>A new <see cref="SpanContext"/> that contains the values obtained from <paramref name="carrier"/>.</returns>
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, DDHttpHeaderNames.TraceId, _traceIdConvention, Log);
if (traceId == TraceId.Zero)
{
// a valid traceId is required to use distributed tracing
return(null);
}
var parentId = ParseUInt64(carrier, getter, DDHttpHeaderNames.ParentId);
var samplingPriority = ParseSamplingPriority(carrier, getter, DDHttpHeaderNames.SamplingPriority);
var origin = PropagationHelpers.ParseString(carrier, getter, DDHttpHeaderNames.Origin);
return(new SpanContext(traceId, parentId, samplingPriority, null, origin));
}
/// <inheritdoc cref="IPropagator"/>
public virtual 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, _traceIdConvention, 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));
}
