Stop using Tracer.Instance if we don't need to (#7744)

## Summary of changes

Updates a couple of places where we're calling `Tracer.Instance` where
we don't need to

## Reason for change

In one of my other PRs I accidentally broke something that should _only_
have affected integration tests, but a bunch of unit tests broke. It
highlighted where they were using `Tracer.Instance` and setting the
global tracer for tests. In other places, it revealed that code that
tests that _looked_ independent of other tests really wasn't...

Calling `Tracer.Instance` potentially does a _lot_ of work, as it
initializes the tracer. It's also hard to follow if we're making static
calls out in places we don't need to. So just pass through the settings
we want instead.

## Implementation details

Instead of calling `Tracer.Instance.Settings`, use the value of `Tracer`
or `TracerSettings` that's already available wherever possible. It makes
the tests cleaner too.

## Test coverage

Same coverage, just a bit cleaner 

## Other details

Included as part of the config stack, just because I already refactored
some of this code, and can't be bothered to faff with merge conflicts:

https://datadoghq.atlassian.net/browse/LANGPLAT-819

- #7522
- #7525
- #7530
- #7532
- #7543
- #7544
- #7721
- #7722
- #7695
- #7723
- #7724
- #7744 👈

Author: andrewlock

tracer/src/Datadog.Trace/ClrProfiler/AutoInstrumentation/AdoNet/DbScopeFactory.cs

@@ -138,6 +138,7 @@ static bool HasDbType(Span span, string dbType)
         }
 
         public static bool TryGetIntegrationDetails(
+            HashSet<string> disabledAdoNetCommandTypes,
             string? commandTypeFullName,
             [NotNullWhen(true)] out IntegrationId? integrationId,
             [NotNullWhen(true)] out string? dbType)
@@ -172,7 +173,7 @@ public static bool TryGetIntegrationDetails(
                     return true;
                 default:
                     string commandTypeName = commandTypeFullName.Substring(commandTypeFullName.LastIndexOf(".", StringComparison.Ordinal) + 1);
-                    if (IsDisabledCommandType(commandTypeName))
+                    if (IsDisabledCommandType(commandTypeName, disabledAdoNetCommandTypes))
                     {
                         integrationId = null;
                         dbType = null;
@@ -200,14 +201,14 @@ _ when commandTypeName.EndsWith(commandSuffix) =>
             }
         }
 
-        internal static bool IsDisabledCommandType(string commandTypeName)
+        internal static bool IsDisabledCommandType(string commandTypeName, HashSet<string> disabledAdoNetCommandTypes)
         {
             if (string.IsNullOrEmpty(commandTypeName))
             {
                 return false;
             }
 
-            var disabledTypes = Tracer.Instance.Settings.DisabledAdoNetCommandTypes;
+            var disabledTypes = disabledAdoNetCommandTypes;
 
             if (disabledTypes is null || disabledTypes.Count == 0)
             {
@@ -245,7 +246,7 @@ static Cache()
             {
                 CommandType = typeof(TCommand);
 
-                if (TryGetIntegrationDetails(CommandType.FullName, out var integrationId, out var dbTypeName))
+                if (TryGetIntegrationDetails(Tracer.Instance.Settings.DisabledAdoNetCommandTypes, CommandType.FullName, out var integrationId, out var dbTypeName))
                 {
                     // cache values for this TCommand type
                     DbTypeName = dbTypeName;
@@ -275,7 +276,7 @@ static Cache()
 
                 // if command.GetType() != typeof(TCommand), we are probably instrumenting a method
                 // defined in a base class like DbCommand and we can't use the cached values
-                if (TryGetIntegrationDetails(commandType.FullName, out var integrationId, out var dbTypeName))
+                if (TryGetIntegrationDetails(tracer.Settings.DisabledAdoNetCommandTypes, commandType.FullName, out var integrationId, out var dbTypeName))
                 {
                     var operationName = $"{dbTypeName}.query";
                     var tagsFromConnectionString = GetTagsFromConnectionString(command);

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

@@ -29,12 +29,8 @@ 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);
-
-    [TestingAndPrivateOnly]
     internal void Inject<TCarrier>(PathwayContext context, TCarrier headers, bool isDataStreamsLegacyHeadersEnabled)
         where TCarrier : IBinaryHeadersCollection
     {

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

@@ -28,6 +28,7 @@ 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 long _nodeHashBase; // note that this actually represents a `ulong` that we have done an unsafe cast for
     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.ClrProfiler.Managed.Tests/DbScopeFactoryTests.cs

@@ -689,7 +689,7 @@ internal void TryGetIntegrationDetails_CorrectNameGenerated(Type commandType, st
             var command = (IDbCommand)Activator.CreateInstance(commandType)!;
             command.CommandText = DbmCommandText;
 
-            bool result = DbScopeFactory.TryGetIntegrationDetails(command.GetType().FullName, out var actualIntegrationId, out var actualDbType);
+            bool result = DbScopeFactory.TryGetIntegrationDetails([], command.GetType().FullName, out var actualIntegrationId, out var actualDbType);
             Assert.True(result);
             Assert.Equal(expectedIntegrationName, actualIntegrationId.ToString());
             Assert.Equal(expectedDbType, actualDbType);
@@ -698,12 +698,13 @@ internal void TryGetIntegrationDetails_CorrectNameGenerated(Type commandType, st
         [Fact]
         internal void TryGetIntegrationDetails_FailsForKnownCommandType()
         {
-            bool result = DbScopeFactory.TryGetIntegrationDetails("InterceptableDbCommand", out var actualIntegrationId, out var actualDbType);
+            var defaultDisabledCommands = new TracerSettings().DisabledAdoNetCommandTypes;
+            bool result = DbScopeFactory.TryGetIntegrationDetails(defaultDisabledCommands, "InterceptableDbCommand", out var actualIntegrationId, out var actualDbType);
             Assert.False(result);
             Assert.False(actualIntegrationId.HasValue);
             Assert.Null(actualDbType);
 
-            bool result2 = DbScopeFactory.TryGetIntegrationDetails("ProfiledDbCommand", out var actualIntegrationId2, out var actualDbType2);
+            bool result2 = DbScopeFactory.TryGetIntegrationDetails(defaultDisabledCommands, "ProfiledDbCommand", out var actualIntegrationId2, out var actualDbType2);
             Assert.False(result2);
             Assert.False(actualIntegrationId2.HasValue);
             Assert.Null(actualDbType2);
@@ -712,18 +713,18 @@ internal void TryGetIntegrationDetails_FailsForKnownCommandType()
         [Fact]
         internal void TryGetIntegrationDetails_FailsForKnownCommandTypes_AndUserDefined()
         {
-            Tracer.Configure(TracerSettings.Create(new Dictionary<string, object> { { ConfigurationKeys.DisabledAdoNetCommandTypes, "SomeFakeDbCommand" } }));
-            bool result = DbScopeFactory.TryGetIntegrationDetails("InterceptableDbCommand", out var actualIntegrationId, out var actualDbType);
+            var disabledCommandTypes = TracerSettings.Create(new() { { ConfigurationKeys.DisabledAdoNetCommandTypes, "SomeFakeDbCommand" } }).DisabledAdoNetCommandTypes;
+            bool result = DbScopeFactory.TryGetIntegrationDetails(disabledCommandTypes, "InterceptableDbCommand", out var actualIntegrationId, out var actualDbType);
             Assert.False(result);
             Assert.False(actualIntegrationId.HasValue);
             Assert.Null(actualDbType);
 
-            bool result2 = DbScopeFactory.TryGetIntegrationDetails("ProfiledDbCommand", out var actualIntegrationId2, out var actualDbType2);
+            bool result2 = DbScopeFactory.TryGetIntegrationDetails(disabledCommandTypes, "ProfiledDbCommand", out var actualIntegrationId2, out var actualDbType2);
             Assert.False(result2);
             Assert.False(actualIntegrationId2.HasValue);
             Assert.Null(actualDbType2);
 
-            bool result3 = DbScopeFactory.TryGetIntegrationDetails("SomeFakeDbCommand", out var actualIntegrationId3, out var actualDbType3);
+            bool result3 = DbScopeFactory.TryGetIntegrationDetails(disabledCommandTypes, "SomeFakeDbCommand", out var actualIntegrationId3, out var actualDbType3);
             Assert.False(result3);
             Assert.False(actualIntegrationId3.HasValue);
             Assert.Null(actualDbType3);
@@ -740,7 +741,8 @@ internal void TryGetIntegrationDetails_FailsForKnownCommandTypes_AndUserDefined(
         [InlineData("Custom.DB.Command", "AdoNet", "db")]
         internal void TryGetIntegrationDetails_CustomCommandType(string commandTypeFullName, string integrationId, string expectedDbType)
         {
-            DbScopeFactory.TryGetIntegrationDetails(commandTypeFullName, out var actualIntegrationId, out var actualDbType);
+            var defaultDisabledCommands = new TracerSettings().DisabledAdoNetCommandTypes;
+            DbScopeFactory.TryGetIntegrationDetails(defaultDisabledCommands, commandTypeFullName, out var actualIntegrationId, out var actualDbType);
             Assert.Equal(integrationId, actualIntegrationId?.ToString());
             Assert.Equal(expectedDbType, actualDbType);
         }

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];