make nats indy-ready (#15008)

Co-authored-by: Lauri Tulmin <[email protected]>

Author: SylvainJuge

instrumentation/nats/nats-2.17/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/nats/v2_17/ConnectionPublishInstrumentation.java

@@ -21,7 +21,10 @@
 import io.opentelemetry.instrumentation.nats.v2_17.internal.NatsRequest;
 import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
 import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
+import javax.annotation.Nullable;
 import net.bytebuddy.asm.Advice;
+import net.bytebuddy.asm.Advice.AssignReturned;
+import net.bytebuddy.asm.Advice.AssignReturned.ToArguments.ToArgument;
 import net.bytebuddy.description.type.TypeDescription;
 import net.bytebuddy.matcher.ElementMatcher;
 
@@ -118,41 +121,54 @@ public static boolean onEnter(
   @SuppressWarnings("unused")
   public static class PublishReplyToHeadersBodyAdvice {
 
+    public static class AdviceScope {
+      private final NatsRequest request;
+      private final Context context;
+      private final Scope scope;
+
+      private AdviceScope(NatsRequest request, Context context, Scope scope) {
+        this.request = request;
+        this.context = context;
+        this.scope = scope;
+      }
+
+      @Nullable
+      public static AdviceScope start(NatsRequest natsRequest) {
+        Context parentContext = Context.current();
+        if (!PRODUCER_INSTRUMENTER.shouldStart(parentContext, natsRequest)) {
+          return null;
+        }
+        Context context = PRODUCER_INSTRUMENTER.start(parentContext, natsRequest);
+        return new AdviceScope(natsRequest, context, context.makeCurrent());
+      }
+
+      public void end(@Nullable Throwable throwable) {
+        scope.close();
+        PRODUCER_INSTRUMENTER.end(context, request, null, throwable);
+      }
+    }
+
+    @AssignReturned.ToArguments(@ToArgument(value = 2, index = 1))
     @Advice.OnMethodEnter(suppress = Throwable.class)
-    public static void onEnter(
+    public static Object[] onEnter(
         @Advice.This Connection connection,
         @Advice.Argument(0) String subject,
         @Advice.Argument(1) String replyTo,
-        @Advice.Argument(value = 2, readOnly = false) Headers headers,
-        @Advice.Argument(3) byte[] body,
-        @Advice.Local("otelContext") Context otelContext,
-        @Advice.Local("otelScope") Scope otelScope,
-        @Advice.Local("natsRequest") NatsRequest natsRequest) {
-      headers = NatsMessageWritableHeaders.create(headers);
-
-      Context parentContext = Context.current();
-      natsRequest = NatsRequest.create(connection, subject, replyTo, headers, body);
-
-      if (!PRODUCER_INSTRUMENTER.shouldStart(parentContext, natsRequest)) {
-        return;
-      }
-
-      otelContext = PRODUCER_INSTRUMENTER.start(parentContext, natsRequest);
-      otelScope = otelContext.makeCurrent();
+        @Advice.Argument(2) Headers originalHeaders,
+        @Advice.Argument(3) byte[] body) {
+      Headers headers = NatsMessageWritableHeaders.create(originalHeaders);
+      NatsRequest natsRequest = NatsRequest.create(connection, subject, replyTo, headers, body);
+      AdviceScope adviceScope = AdviceScope.start(natsRequest);
+      return new Object[] {adviceScope, headers};
     }
 
     @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
     public static void onExit(
-        @Advice.Thrown Throwable throwable,
-        @Advice.Local("otelContext") Context otelContext,
-        @Advice.Local("otelScope") Scope otelScope,
-        @Advice.Local("natsRequest") NatsRequest natsRequest) {
-      if (otelScope == null) {
-        return;
+        @Advice.Thrown @Nullable Throwable throwable, @Advice.Enter Object[] enterResult) {
+      AdviceScope adviceScope = (AdviceScope) enterResult[0];
+      if (adviceScope != null) {
+        adviceScope.end(throwable);
       }
-
-      otelScope.close();
-      PRODUCER_INSTRUMENTER.end(otelContext, natsRequest, null, throwable);
     }
   }