/*
* Copyright (C) 2010-2101 Alibaba Group Holding Limited.
*
* 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.otter.shared.arbitrate.impl.setl.memory;
import java.util.Date;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.util.Assert;
import com.alibaba.otter.shared.arbitrate.impl.config.ArbitrateConfigUtils;
import com.alibaba.otter.shared.arbitrate.impl.setl.ArbitrateFactory;
import com.alibaba.otter.shared.arbitrate.impl.setl.SelectArbitrateEvent;
import com.alibaba.otter.shared.arbitrate.impl.setl.monitor.PermitMonitor;
import com.alibaba.otter.shared.arbitrate.model.EtlEventData;
import com.alibaba.otter.shared.common.model.config.channel.ChannelStatus;
import com.alibaba.otter.shared.common.model.config.enums.StageType;
/**
* 基于memory的仲裁器实现
*
* @author jianghang 2012-9-27 下午10:05:08
* @version 4.1.0
*/
public class SelectMemoryArbitrateEvent implements SelectArbitrateEvent {
private static final Logger logger = LoggerFactory.getLogger(SelectMemoryArbitrateEvent.class);
public EtlEventData await(Long pipelineId) throws InterruptedException {
Assert.notNull(pipelineId);
PermitMonitor permitMonitor = ArbitrateFactory.getInstance(pipelineId, PermitMonitor.class);
permitMonitor.waitForPermit();// 阻塞等待授权
MemoryStageController stageController = ArbitrateFactory.getInstance(pipelineId, MemoryStageController.class);
Long processId = stageController.waitForProcess(StageType.SELECT); // 符合条件的processId
ChannelStatus status = permitMonitor.getChannelPermit();
if (status.isStart()) {// 即时查询一下当前的状态，状态随时可能会变
EtlEventData eventData = new EtlEventData();
eventData.setPipelineId(pipelineId);
eventData.setProcessId(processId);
eventData.setStartTime(new Date().getTime());// 返回当前时间
Long nid = ArbitrateConfigUtils.getCurrentNid();
eventData.setCurrNid(nid);
eventData.setNextNid(nid);
return eventData;// 只有这一条路返回
} else {
logger.warn("pipelineId[{}] select ignore processId[{}] by status[{}]", new Object[] { pipelineId,
processId, status });
stageController.clearProgress(processId);//将progress中清理掉，避免阻塞后续调度，因为最小的Id一直处于extract未完成阶段
return await(pipelineId);// 递归调用
}
}
public void single(EtlEventData data) {
Assert.notNull(data);
MemoryStageController stageController = ArbitrateFactory.getInstance(data.getPipelineId(),
MemoryStageController.class);
stageController.single(StageType.SELECT, data);// 通知下一个节点
}
}