/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.accumulo.core.trace.wrappers;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
/**
* To move trace data from client to server, the RPC call must be annotated to take a TInfo object as its first argument. The user can simply pass null, so long
* as they wrap their Client and Service objects with these functions.
*
* <pre>
* Trace.on("remoteMethod");
* Iface c = new Client();
* c = TraceWrap.client(c);
* c.remoteMethod(null, arg2, arg3);
* Trace.off();
* </pre>
*
* The wrapper will see the annotated method and send or re-establish the trace information.
*
* Note that the result of these calls is a Proxy object that conforms to the basic interfaces, but is not your concrete instance.
*
*/
public class TraceWrap {
public static <T> T service(final T instance) {
InvocationHandler handler = new RpcServerInvocationHandler<>(instance);
return wrappedInstance(handler, instance);
}
public static <T> T client(final T instance) {
InvocationHandler handler = new RpcClientInvocationHandler<>(instance);
return wrappedInstance(handler, instance);
}
private static <T> T wrappedInstance(final InvocationHandler handler, final T instance) {
@SuppressWarnings("unchecked")
T proxiedInstance = (T) Proxy.newProxyInstance(instance.getClass().getClassLoader(), instance.getClass().getInterfaces(), handler);
return proxiedInstance;
}
}