/*
* Copyright 1999-2015 dangdang.com.
* <p>
* 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.
* </p>
*/
package com.dangdang.ddframe.rdb.sharding.executor.event;
import com.google.common.eventbus.EventBus;
import java.util.concurrent.ConcurrentHashMap;
/**
* 事件总线.
*
* @author gaohongtao
*/
public class ExecutionEventBus {
private final EventBus instance = new EventBus();
private final ConcurrentHashMap<String, ExecutionEventListener> listeners = new ConcurrentHashMap<>();
/**
* SQL执行事件.
*
* @param event SQL执行事件
*/
public void post(final ExecutionEvent event) {
if (listeners.isEmpty()) {
return;
}
instance.post(event);
}
/**
* 注册事件监听器.
*
* @param listener DML类SQL执行事件监听器
*/
public void register(final ExecutionEventListener listener) {
if (null != listeners.putIfAbsent(listener.getName(), listener)) {
return;
}
instance.register(listener);
}
/**
* 清除监听器.
*/
public synchronized void clearListener() {
for (ExecutionEventListener each : listeners.values()) {
instance.unregister(each);
}
listeners.clear();
}
}