/*
* Copyright 1999-2011 Alibaba Group.
*
* Licensed 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 com.alibaba.dubbo.rpc.protocol.dubbo;
import java.util.Set;
import java.util.concurrent.locks.ReentrantLock;
import com.alibaba.dubbo.common.Constants;
import com.alibaba.dubbo.common.URL;
import com.alibaba.dubbo.common.utils.AtomicPositiveInteger;
import com.alibaba.dubbo.remoting.RemotingException;
import com.alibaba.dubbo.remoting.TimeoutException;
import com.alibaba.dubbo.remoting.exchange.ExchangeClient;
import com.alibaba.dubbo.remoting.exchange.ResponseFuture;
import com.alibaba.dubbo.rpc.Invocation;
import com.alibaba.dubbo.rpc.Invoker;
import com.alibaba.dubbo.rpc.Result;
import com.alibaba.dubbo.rpc.RpcContext;
import com.alibaba.dubbo.rpc.RpcException;
import com.alibaba.dubbo.rpc.RpcInvocation;
import com.alibaba.dubbo.rpc.RpcResult;
import com.alibaba.dubbo.rpc.protocol.AbstractInvoker;
/**
* DubboInvoker
*
* @author william.liangf
* @author chao.liuc
*/
public class DubboInvoker<T> extends AbstractInvoker<T> {
private final ExchangeClient[] clients;
private final AtomicPositiveInteger index = new AtomicPositiveInteger();
private final String version;
private final ReentrantLock destroyLock = new ReentrantLock();
private final Set<Invoker<?>> invokers;
public DubboInvoker(Class<T> serviceType, URL url, ExchangeClient[] clients){
this(serviceType, url, clients, null);
}
public DubboInvoker(Class<T> serviceType, URL url, ExchangeClient[] clients, Set<Invoker<?>> invokers){
super(serviceType, url, new String[] {Constants.INTERFACE_KEY, Constants.GROUP_KEY, Constants.TOKEN_KEY, Constants.TIMEOUT_KEY});
this.clients = clients;
// get version.
this.version = url.getParameter(Constants.VERSION_KEY, "0.0.0");
this.invokers = invokers;
}
@Override
protected Result doInvoke(final Invocation invocation) throws Throwable {
RpcInvocation inv = null;
final String methodName ;
if(Constants.$INVOKE.equals(invocation.getMethodName())
&& invocation.getArguments() != null
&& invocation.getArguments().length >0
&& invocation.getArguments()[0] != null){
inv = (RpcInvocation) invocation;
//the frist argument must be real method name;
methodName = invocation.getArguments()[0].toString();
}else {
inv = new RpcInvocation(invocation);
methodName = invocation.getMethodName();
}
inv.setAttachment(Constants.PATH_KEY, getUrl().getPath());
inv.setAttachment(Constants.VERSION_KEY, version);
ExchangeClient currentClient;
if (clients.length == 1) {
currentClient = clients[0];
} else {
currentClient = clients[index.getAndIncrement() % clients.length];
}
try {
// 不可靠异步
boolean isAsync = getUrl().getMethodParameter(methodName, Constants.ASYNC_KEY, false);
int timeout = getUrl().getMethodParameter(methodName, Constants.TIMEOUT_KEY,Constants.DEFAULT_TIMEOUT);
if (isAsync) {
boolean isReturn = getUrl().getMethodParameter(methodName, Constants.RETURN_KEY, true);
if (isReturn) {
ResponseFuture future = currentClient.request(inv, timeout) ;
RpcContext.getContext().setFuture(new FutureAdapter<Object>(future));
} else {
boolean isSent = getUrl().getMethodParameter(methodName, Constants.SENT_KEY, false);
currentClient.send(inv, isSent);
RpcContext.getContext().setFuture(null);
}
return new RpcResult();
}
RpcContext.getContext().setFuture(null);
return (Result) currentClient.request(inv, timeout).get();
} catch (TimeoutException e) {
throw new RpcException(RpcException.TIMEOUT_EXCEPTION, "Invoke remote method timeout. method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
} catch (RemotingException e) {
throw new RpcException(RpcException.NETWORK_EXCEPTION, "Can not connect to prvoider. method: " + invocation.getMethodName() + ", provider: " + getUrl() + ", cause: " + e.getMessage(), e);
}
}
@Override
public boolean isAvailable() {
if (!super.isAvailable())
return false;
for (ExchangeClient client : clients){
if (client.isConnected() && !client.hasAttribute(Constants.CHANNEL_ATTRIBUTE_READONLY_KEY)){
//cannot write == not Available ?
return true ;
}
}
return false;
}
public void destroy() {
//防止client被关闭多次.在connect per jvm的情况下，client.close方法会调用计数器-1，当计数器小于等于0的情况下，才真正关闭
if (super.isDestroyed()){
return ;
} else {
//dubbo check ,避免多次关闭
destroyLock.lock();
try{
if (super.isDestroyed()){
return ;
}
super.destroy();
if (invokers != null){
invokers.remove(this);
}
for (ExchangeClient client : clients) {
try {
client.close();
} catch (Throwable t) {
logger.warn(t.getMessage(), t);
}
}
}finally {
destroyLock.unlock();
}
}
}
}