云计算仿真工具中文注释DeferredQueue.java

 

/* * Title:        CloudSim Toolkit * Description:  CloudSim (Cloud Simulation) Toolkit for Modeling and Simulation of Clouds * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html * * Copyright (c) 2009-2010, The University of Melbourne, Australia */package org.cloudbus.cloudsim.core;import java.util.Iterator;import java.util.LinkedList;import java.util.List;import java.util.ListIterator;/** * 这个类是defer队列，使用linkedlist结构，元素按事件发生时间排序 * 方法： * 添加事件 * 返回迭代器 * 返回大小 * 清除队列 * This class implements the deferred event queue used by {@link Simulation}. * The event queue uses a linked list to store the events. * * @authorMarcos Dias de Assuncao * @sinceCloudSim Toolkit 1.0 * * @seeSimulation * @seeSimEvent */public class DeferredQueue {/** The list. */private final List<SimEvent> list = new LinkedList<SimEvent>();/**  * The max time. * 事件发生的最晚时间 *  */private double maxTime = -1;/** * 事件加入队列时，维护元素的顺序，按事件发生事件顺序加入 * Adds a new event to the queue. Adding a new event to the queue * preserves the temporal order of the events. * @param newEvent The event to be added to the queue. */public void addEvent(SimEvent newEvent) {// The event has to be inserted as the last of all events// with the same event_time(). Yes, this matters.//返回时间必须发生的时间double eventTime = newEvent.eventTime();if (eventTime >= maxTime) {list.add(newEvent);maxTime = eventTime;return;}ListIterator<SimEvent> iterator = list.listIterator();SimEvent event;//从第一个元素开始搜索while (iterator.hasNext()) {event = iterator.next();if (event.eventTime() > eventTime) {iterator.previous();iterator.add(newEvent);return;}}//队列为空    list.add(newEvent);}/** * Returns an iterator to the events in the queue. * * @return the iterator */public Iterator<SimEvent> iterator() {return list.iterator();}/** * Returns the size of this event queue. * * @return the number of events in the queue. */public int size() {return list.size();}/** * Clears the queue. */public void clear(){list.clear();}}