content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.reactornetty.v1_0;
  
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.returns;
  
  import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
  import net.bytebuddy.asm.Advice;
  import net.bytebuddy.description.type.TypeDescription;
  import net.bytebuddy.matcher.ElementMatcher;
  import reactor.core.publisher.Mono;
  import reactor.netty.Connection;
  import reactor.netty.http.client.HttpClient;
  import reactor.netty.http.client.HttpClientConfig;
  import reactor.netty.http.client.HttpClientConfigBuddy;
  
  public class HttpClientConnectInstrumentation implements TypeInstrumentation {
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return named("reactor.netty.http.client.HttpClientConnect");
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      transformer.applyAdviceToMethod(
          named("connect").and(returns(named("reactor.core.publisher.Mono"))),
          this.getClass().getName() + "$ConnectAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class ConnectAdvice {
  
      @Advice.OnMethodExit(suppress = Throwable.class)
      public static void onExit(
          @Advice.Return(readOnly = false) Mono<? extends Connection> connection,
          @Advice.This HttpClient httpClient) {
  
        HttpClientConfig config = httpClient.configuration();
        // reactor-netty 1.0.x has a bug: the .mapConnect() function is not applied when deferred
        // configuration is used
        // we're fixing this bug here, so that our instrumentation can safely add its own
        // .mapConnect() listener
        if (HttpClientConfigBuddy.hasDeferredConfig(config)) {
          connection = HttpClientConfigBuddy.getConnector(config).apply(connection);
        }
      }
    }
  }
  