DistributedContextPropagator.cs

Go to the documentation of this file.

using System.Collections.Generic;
using System.Net;
using System.Text;
 
namespace System.Diagnostics;
 
public abstract class DistributedContextPropagator
{
    public delegate void PropagatorGetterCallback(object? carrier, string fieldName, out string? fieldValue, out IEnumerable<string>? fieldValues);
 
    public delegate void PropagatorSetterCallback(object? carrier, string fieldName, string fieldValue);
 
    private static DistributedContextPropagator s_current = CreateDefaultPropagator();
 
    internal static readonly char[] s_trimmingSpaceCharacters = new char[2] { ' ', '\t' };
 
    public abstract IReadOnlyCollection<string> Fields { get; }
 
    public static DistributedContextPropagator Current
    {
        get
        {
            return s_current;
        }
        set
        {
            s_current = value ?? throw new ArgumentNullException("value");
        }
    }
 
    public abstract void Inject(Activity? activity, object? carrier, PropagatorSetterCallback? setter);
 
    public abstract void ExtractTraceIdAndState(object? carrier, PropagatorGetterCallback? getter, out string? traceId, out string? traceState);
 
    public abstract IEnumerable<KeyValuePair<string, string?>>? ExtractBaggage(object? carrier, PropagatorGetterCallback? getter);
 
    public static DistributedContextPropagator CreateDefaultPropagator()
    {
        return LegacyPropagator.Instance;
    }
 
    public static DistributedContextPropagator CreatePassThroughPropagator()
    {
        return PassThroughPropagator.Instance;
    }
 
    public static DistributedContextPropagator CreateNoOutputPropagator()
    {
        return NoOutputPropagator.Instance;
    }
 
    internal static void InjectBaggage(object carrier, IEnumerable<KeyValuePair<string, string>> baggage, PropagatorSetterCallback setter)
    {
        using IEnumerator<KeyValuePair<string, string>> enumerator = baggage.GetEnumerator();
        if (enumerator.MoveNext())
        {
            StringBuilder stringBuilder = new StringBuilder();
            do
            {
                KeyValuePair<string, string> current = enumerator.Current;
                stringBuilder.Append(WebUtility.UrlEncode(current.Key)).Append('=').Append(WebUtility.UrlEncode(current.Value))
                    .Append(", ");
            }
            while (enumerator.MoveNext());
            setter(carrier, "Correlation-Context", stringBuilder.ToString(0, stringBuilder.Length - 2));
        }
    }
}