/* | |
* 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 com.alibaba.dubbo.rpc.cluster.loadbalance; | |
import com.alibaba.dubbo.common.Constants; | |
import com.alibaba.dubbo.common.URL; | |
import com.alibaba.dubbo.rpc.Invocation; | |
import com.alibaba.dubbo.rpc.Invoker; | |
import com.alibaba.dubbo.rpc.cluster.LoadBalance; | |
import java.util.List; | |
/** | |
* AbstractLoadBalance | |
* | |
*/ | |
public abstract class AbstractLoadBalance implements LoadBalance { | |
static int calculateWarmupWeight(int uptime, int warmup, int weight) { | |
int ww = (int) ((float) uptime / ((float) warmup / (float) weight)); | |
return ww < 1 ? 1 : (ww > weight ? weight : ww); | |
} | |
@Override | |
public <T> Invoker<T> select(List<Invoker<T>> invokers, URL url, Invocation invocation) { | |
if (invokers == null || invokers.isEmpty()) | |
return null; | |
if (invokers.size() == 1) | |
return invokers.get(0); | |
return doSelect(invokers, url, invocation); | |
} | |
protected abstract <T> Invoker<T> doSelect(List<Invoker<T>> invokers, URL url, Invocation invocation); | |
protected int getWeight(Invoker<?> invoker, Invocation invocation) { | |
int weight = invoker.getUrl().getMethodParameter(invocation.getMethodName(), Constants.WEIGHT_KEY, Constants.DEFAULT_WEIGHT); | |
if (weight > 0) { | |
long timestamp = invoker.getUrl().getParameter(Constants.REMOTE_TIMESTAMP_KEY, 0L); | |
if (timestamp > 0L) { | |
int uptime = (int) (System.currentTimeMillis() - timestamp); | |
int warmup = invoker.getUrl().getParameter(Constants.WARMUP_KEY, Constants.DEFAULT_WARMUP); | |
if (uptime > 0 && uptime < warmup) { | |
weight = calculateWarmupWeight(uptime, warmup, weight); | |
} | |
} | |
} | |
return weight; | |
} | |
} |