Update DSM to stop using the global tracer instance

Author: andrewlock

tracer/src/Datadog.Trace/DataStreamsMonitoring/DataStreamsContextPropagator.cs

@@ -28,12 +28,8 @@ internal class DataStreamsContextPropagator
     /// </summary>
     /// <param name="context">A <see cref="PathwayContext"/> value that will be propagated into <paramref name="headers"/>.</param>
     /// <param name="headers">A <see cref="IHeadersCollection"/> to add new headers to.</param>
+    /// <param name="isDataStreamsLegacyHeadersEnabled">Are legacy DSM headers enabled</param>
     /// <typeparam name="TCarrier">Type of header collection</typeparam>
-    public void Inject<TCarrier>(PathwayContext context, TCarrier headers)
-        where TCarrier : IBinaryHeadersCollection
-        => Inject(context, headers, Tracer.Instance.Settings.IsDataStreamsLegacyHeadersEnabled);
-
-    // Internal for testing
     internal void Inject<TCarrier>(PathwayContext context, TCarrier headers, bool isDataStreamsLegacyHeadersEnabled)
         where TCarrier : IBinaryHeadersCollection
     {

tracer/src/Datadog.Trace/DataStreamsMonitoring/DataStreamsManager.cs

@@ -29,6 +29,7 @@ internal class DataStreamsManager
     private static readonly AsyncLocal<PathwayContext?> LastConsumePathway = new(); // saves the context on consume checkpointing only
     private readonly ConcurrentDictionary<string, RateLimiter> _schemaRateLimiters = new();
     private readonly IDisposable _updateSubscription;
+    private readonly bool _isLegacyDsmHeadersEnabled;
     private ulong _nodeHashBase;
     private bool _isEnabled;
     private bool _isInDefaultState;
@@ -40,6 +41,7 @@ public DataStreamsManager(
     {
         UpdateNodeHash(tracerSettings.Manager.InitialMutableSettings);
         _isEnabled = writer is not null;
+        _isLegacyDsmHeadersEnabled = tracerSettings.IsDataStreamsLegacyHeadersEnabled;
         _writer = writer;
         _isInDefaultState = tracerSettings.IsDataStreamsMonitoringInDefaultState;
         _updateSubscription = tracerSettings.Manager.SubscribeToChanges(updates =>
@@ -129,7 +131,7 @@ public void InjectPathwayContext<TCarrier>(PathwayContext? context, TCarrier hea
             return;
         }
 
-        DataStreamsContextPropagator.Instance.Inject(context.Value, headers);
+        DataStreamsContextPropagator.Instance.Inject(context.Value, headers, _isLegacyDsmHeadersEnabled);
     }
 
     public void TrackBacklog(string tags, long value)

tracer/test/Datadog.Trace.Tests/DataStreamsMonitoring/DataStreamsContextPropagatorTests.cs

@@ -15,8 +15,9 @@ namespace Datadog.Trace.Tests.DataStreamsMonitoring
 {
     public class DataStreamsContextPropagatorTests
     {
-        [Fact]
-        public void CanRoundTripPathwayContext()
+        [Theory]
+        [CombinatorialData]
+        public void CanRoundTripPathwayContext(bool isDataStreamsLegacyHeadersEnabled)
         {
             var oneMs = TimeSpan.FromMilliseconds(1);
             var headers = new TestHeadersCollection();
@@ -25,7 +26,7 @@ public void CanRoundTripPathwayContext()
                 DateTimeOffset.UtcNow.AddSeconds(-5).ToUnixTimeNanoseconds(),
                 DateTimeOffset.UtcNow.ToUnixTimeNanoseconds());
 
-            DataStreamsContextPropagator.Instance.Inject(context, headers);
+            DataStreamsContextPropagator.Instance.Inject(context, headers, isDataStreamsLegacyHeadersEnabled);
 
             var extracted = DataStreamsContextPropagator.Instance.Extract(headers);
 
@@ -86,16 +87,17 @@ public void Extract_WhenBothHeadersPresent_PrefersBase64Header()
             extractedContext.Value.EdgeStart.Should().NotBe(binaryContext.EdgeStart);
         }
 
-        [Fact]
-        public void InjectedHeaders_HaveCorrectFormat()
+        [Theory]
+        [CombinatorialData]
+        public void InjectedHeaders_HaveCorrectFormat(bool isDataStreamsLegacyHeadersEnabled)
         {
             var headers = new TestHeadersCollection();
             var context = new PathwayContext(
                 new PathwayHash(0x12345678),
                 0x1122334455667788,
                 unchecked((long)0x99AABBCCDDEEFF00));
 
-            DataStreamsContextPropagator.Instance.Inject(context, headers);
+            DataStreamsContextPropagator.Instance.Inject(context, headers, isDataStreamsLegacyHeadersEnabled);
 
             headers.Values.Should().ContainKey(DataStreamsPropagationHeaders.PropagationKeyBase64);
             var base64HeaderValueBytes = headers.Values[DataStreamsPropagationHeaders.PropagationKeyBase64];