content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.liberty.dispatcher;
  
  import static io.opentelemetry.javaagent.instrumentation.liberty.dispatcher.LibertyDispatcherSingletons.instrumenter;
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
  
  import com.ibm.ws.http.channel.internal.inbound.HttpInboundServiceContextImpl;
  import com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink;
  import com.ibm.wsspi.http.channel.values.StatusCodes;
  import io.opentelemetry.context.Context;
  import io.opentelemetry.context.Scope;
  import io.opentelemetry.javaagent.bootstrap.Java8BytecodeBridge;
  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;
  
  /**
   * Instrumenting
   * https://github.com/OpenLiberty/open-liberty/blob/master/dev/com.ibm.ws.transport.http/src/com/ibm/ws/http/dispatcher/internal/channel/HttpDispatcherLink.java
   * We instrument sendResponse method that is called when no application has been deployed under
   * requested context root or something goes horribly wrong and server responds with Internal Server
   * Error
   */
  public class LibertyDispatcherLinkInstrumentation implements TypeInstrumentation {
  
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return named("com.ibm.ws.http.dispatcher.internal.channel.HttpDispatcherLink");
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      // https://github.com/OpenLiberty/open-liberty/blob/master/dev/com.ibm.ws.transport.http/src/com/ibm/ws/http/dispatcher/internal/channel/HttpDispatcherLink.java
      transformer.applyAdviceToMethod(
          named("sendResponse")
              .and(takesArgument(0, named("com.ibm.wsspi.http.channel.values.StatusCodes")))
              .and(takesArgument(1, named(String.class.getName())))
              .and(takesArgument(2, named(Exception.class.getName())))
              .and(takesArgument(3, named(boolean.class.getName()))),
          this.getClass().getName() + "$SendResponseAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class SendResponseAdvice {
  
      @Advice.OnMethodEnter(suppress = Throwable.class)
      public static void onEnter(
          @Advice.FieldValue("isc") HttpInboundServiceContextImpl isc,
          @Advice.Local("otelRequest") LibertyRequest request,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope) {
        Context parentContext = Java8BytecodeBridge.currentContext();
        request =
            new LibertyRequest(
                isc.getRequest(),
                isc.getLocalAddr(),
                isc.getLocalPort(),
                isc.getRemoteAddr(),
                isc.getRemotePort());
        if (!instrumenter().shouldStart(parentContext, request)) {
          return;
        }
        context = instrumenter().start(parentContext, request);
        scope = context.makeCurrent();
      }
  
      @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
      public static void stopSpan(
          @Advice.This HttpDispatcherLink httpDispatcherLink,
          @Advice.Thrown Throwable throwable,
          @Advice.Argument(value = 0) StatusCodes statusCode,
          @Advice.Argument(value = 2) Exception failure,
          @Advice.Local("otelRequest") LibertyRequest request,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope) {
        if (scope == null) {
          return;
        }
        scope.close();
  
        LibertyResponse response = new LibertyResponse(httpDispatcherLink, statusCode);
  
        Throwable t = failure != null ? failure : throwable;
        instrumenter().end(context, request, response, t);
      }
    }
  }
  