content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.gwt;
  
  import static io.opentelemetry.javaagent.instrumentation.gwt.GwtSingletons.instrumenter;
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
  import static net.bytebuddy.matcher.ElementMatchers.takesArguments;
  
  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 java.lang.reflect.Method;
  import net.bytebuddy.asm.Advice;
  import net.bytebuddy.description.type.TypeDescription;
  import net.bytebuddy.matcher.ElementMatcher;
  
  public class GwtRpcInstrumentation implements TypeInstrumentation {
  
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return named("com.google.gwt.user.server.rpc.RPC");
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      transformer.applyAdviceToMethod(
          named("invokeAndEncodeResponse")
              .and(takesArguments(5))
              .and(takesArgument(0, Object.class))
              .and(takesArgument(1, Method.class))
              .and(takesArgument(2, Object[].class))
              .and(takesArgument(3, named("com.google.gwt.user.server.rpc.SerializationPolicy")))
              .and(takesArgument(4, int.class)),
          this.getClass().getName() + "$InvokeAndEncodeResponseAdvice");
  
      // encodeResponseForFailure is called by invokeAndEncodeResponse in case of failure
      transformer.applyAdviceToMethod(
          named("encodeResponseForFailure")
              .and(takesArguments(4))
              .and(takesArgument(0, Method.class))
              .and(takesArgument(1, Throwable.class))
              .and(takesArgument(2, named("com.google.gwt.user.server.rpc.SerializationPolicy")))
              .and(takesArgument(3, int.class)),
          this.getClass().getName() + "$EncodeResponseForFailureAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class InvokeAndEncodeResponseAdvice {
  
      @Advice.OnMethodEnter(suppress = Throwable.class)
      public static void onEnter(
          @Advice.Argument(1) Method method,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope) {
        context =
            instrumenter()
                .start(Java8BytecodeBridge.currentContext(), method)
                .with(GwtSingletons.RPC_CONTEXT_KEY, true);
        scope = context.makeCurrent();
      }
  
      @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
      public static void onExit(
          @Advice.Argument(1) Method method,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope,
          @Advice.Thrown Throwable throwable) {
        scope.close();
  
        instrumenter().end(context, method, null, throwable);
      }
    }
  
    @SuppressWarnings("unused")
    public static class EncodeResponseForFailureAdvice {
  
      @Advice.OnMethodEnter(suppress = Throwable.class)
      public static void onEnter(@Advice.Argument(1) Throwable throwable) {
        if (throwable == null) {
          return;
        }
        Context context = Java8BytecodeBridge.currentContext();
        if (context.get(GwtSingletons.RPC_CONTEXT_KEY) == null) {
          // not inside rpc invocation
          return;
        }
        Java8BytecodeBridge.spanFromContext(context).recordException(throwable);
      }
    }
  }
  