content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.undertow;
  
  import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.extendsClass;
  import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.hasClassesNamed;
  import static io.opentelemetry.javaagent.instrumentation.undertow.UndertowSingletons.helper;
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
  
  import io.opentelemetry.context.Context;
  import io.opentelemetry.javaagent.bootstrap.CallDepth;
  import io.opentelemetry.javaagent.bootstrap.http.HttpServerResponseCustomizerHolder;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
  import io.undertow.server.HttpServerExchange;
  import io.undertow.server.ServerConnection;
  import net.bytebuddy.asm.Advice;
  import net.bytebuddy.description.type.TypeDescription;
  import net.bytebuddy.matcher.ElementMatcher;
  
  public class HttpServerConnectionInstrumentation implements TypeInstrumentation {
  
    @Override
    public ElementMatcher<ClassLoader> classLoaderOptimization() {
      return hasClassesNamed("io.undertow.server.ServerConnection");
    }
  
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return extendsClass(named("io.undertow.server.ServerConnection"));
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      transformer.applyAdviceToMethod(
          named("getSinkConduit")
              .and(takesArgument(0, named("io.undertow.server.HttpServerExchange"))),
          this.getClass().getName() + "$ResponseAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class ResponseAdvice {
  
      @Advice.OnMethodEnter(suppress = Throwable.class)
      public static void onEnter(
          @Advice.Argument(0) HttpServerExchange exchange,
          @Advice.Local("otelCallDepth") CallDepth callDepth) {
        callDepth = CallDepth.forClass(ServerConnection.class);
        if (callDepth.getAndIncrement() > 0) {
          return;
        }
  
        Context context = helper().getServerContext(exchange);
        HttpServerResponseCustomizerHolder.getCustomizer()
            .customize(context, exchange, UndertowHttpResponseMutator.INSTANCE);
      }
  
      @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
      public static void onExit(@Advice.Local("otelCallDepth") CallDepth callDepth) {
        callDepth.decrementAndGet();
      }
    }
  }
  