云计算仿真工具中文注释CloudInformationService.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.Calendar;import java.util.Collection;import java.util.Iterator;import java.util.LinkedList;import java.util.List;import org.cloudbus.cloudsim.Log;/** * 一个云信息中心是一个实体，继承实体类，实体允许网格资源注册，标记和发现服务。 * 其他实体如资源代理可以联系这个类用于发现是否可以服务，CIS会返回一系列的注册资源的ID * 总之，它扮演的是黄页服务 * 这个类在cloudsim初始化是创建，cloudsim.init()中创建，因此不用担心创建这个类。 * 这个类在cloudsim初始化是创建，cloudsim.init()中创建，因此不用担心创建这个类。 * 方法总结： * 实体启动，任何实体都必须覆盖的方法 * 事件处理，任何实体都必须覆盖的方法 * CIS关闭 * 检查某个ID实体是否在Advanced Reservations * 实体ID是否存在 * 向列表中各个实体发送END_OF_SIMULATION消息,该消息延迟时间为0 * A Cloud Information Service (GIS) is an entity that provides grid * resource registration, indexing and discovery services. The Cloud hostList * tell their readiness to process Cloudlets by registering themselves with * this entity, done via {@link gridsim.CloudResource#startEntity()} method. * <p> * Other entities such as the resource broker can contact * this class for resource discovery service, which returns a list of * registered resource IDs. In summary, it acts like a yellow page service. * <p> * This class will be created by CloudSim upon initialisation of the simulation, * i.e. done via {@link gridsim.CloudSim#init(int, Calendar, boolean)} method. * Hence, do not need to worry about creating an object of this class. * <p> * @authorManzur Murshed * @authorRajkumar Buyya * @sinceCloudSim Toolkit 1.0 */public class CloudInformationService extends SimEntity {    /** For all types of hostList. */    private final List<Integer> resList;    /** Only for AR hostList. */    private final List<Integer> arList;    /** List of all regional GIS. */    private final List<Integer> gisList;    /**     * Allocates a new CloudInformationService object.     * @param name       the name to be associated with this entity (as     * required by SimEntity class)     * @throws Exception This happens when creating this entity before     * initialising CloudSim package or this entity name is     * <tt>null</tt> or empty     * @see gridsim.CloudSim#init(int, Calendar, boolean)     * @see yoursim.SimEntity     * @pre name != null     * @post $none     */public CloudInformationService(String name) throws Exception {super(name);resList = new LinkedList<Integer>();arList = new LinkedList<Integer>();gisList = new LinkedList<Integer>();}    /**     * 实体启动，任何实体都必须覆盖的方法     * Starts the CloudInformationService entity.     */    @Overridepublic void startEntity() { }    /**     * 事件处理，任何实体都必须覆盖的方法     * Processes events scheduled for this entity.     *     * @param ev the event to be handled.     *     * @see SimEntity#processEvent(SimEvent)     */    @Overridepublic void processEvent(SimEvent ev) {    int id = -1;  // requester id        switch ( ev.getTag() )        {                // storing regional GIS id            case CloudSimTags.REGISTER_REGIONAL_GIS:                gisList.add( (Integer) ev.getData() );                break;                // request for all regional GIS list            case CloudSimTags.REQUEST_REGIONAL_GIS:                // Get ID of an entity that send this event                id = ( (Integer) ev.getData() ).intValue();                // Send the regional GIS list back to sender                super.send(id, 0L, ev.getTag(), gisList);                break;                // A resource is requesting to register.            case CloudSimTags.REGISTER_RESOURCE:                resList.add( (Integer) ev.getData() );                break;                // A resource that can support Advance Reservation            case CloudSimTags.REGISTER_RESOURCE_AR:                resList.add( (Integer) ev.getData() );                arList.add( (Integer) ev.getData() );                break;                // A Broker is requesting for a list of all hostList.            case CloudSimTags.RESOURCE_LIST:                // Get ID of an entity that send this event                id = ( (Integer) ev.getData() ).intValue();                // Send the resource list back to the sender                super.send(id, 0L, ev.getTag(), resList);                break;                // A Broker is requesting for a list of all hostList.            case CloudSimTags.RESOURCE_AR_LIST:                // Get ID of an entity that send this event                id = ( (Integer) ev.getData() ).intValue();                // Send the resource AR list back to the sender                super.send(id, 0L, ev.getTag(), arList);                break;            default:                processOtherEvent(ev);                break;        }    }    /**     * CIS关闭     * Shutdowns the CloudInformationService.     */    @Overridepublic void shutdownEntity() {    notifyAllEntity();    }    /**     * Gets the list of all CloudResource IDs, including hostList that support     * Advance Reservation.     *     * @return LinkedList containing resource IDs. Each ID is represented by     * an Integer object.     *     * @pre $none     * @post $none     */    public List<Integer> getList() {        return resList;    }    /**     * Gets the list of CloudResource IDs that <b>only</b> support     * Advanced Reservation.     *     * @return LinkedList containing resource IDs. Each ID is represented by     * an Integer object.     *     * @pre $none     * @post $none     */    public List<Integer> getAdvReservList() {        return arList;    }    /**     * 检查某个ID实体是否在Advanced Reservations     * Checks whether a given resource ID supports Advanced Reservations or not.     *     * @param id  a resource ID     *     * @return <tt>true</tt> if this resource supports Advanced Reservations,     * <tt>false</tt> otherwise     *     * @pre id != null     * @post $none     */public boolean resourceSupportAR(Integer id) {if (id == null) {return false;}return resourceSupportAR(id.intValue());}    /**     * 检查某个ID实体是否在Advanced Reservations     * Checks whether a given resource ID supports Advanced Reservations or not.     *     * @param id  a resource ID     *     * @return <tt>true</tt> if this resource supports Advanced Reservations,     * <tt>false</tt> otherwise     *     * @pre id >= 0     * @post $none     */public boolean resourceSupportAR(int id) {boolean flag = false;if (id < 0) {flag = false;} else {flag = checkResource(arList, id);}return flag;}    /**     * 实体ID是否存在     * Checks whether the given CloudResource ID exists or not.     *     * @param id    a CloudResource id     *     * @return <tt>true</tt> if the given ID exists, <tt>false</tt> otherwise     *     * @pre id >= 0     * @post $none     */    public boolean resourceExist(int id) {        boolean flag = false;        if (id < 0) {            flag = false;        } else {            flag = checkResource(resList, id);        }        return flag;    }    /**     * Checks whether the given CloudResource ID exists or not.     *     * @param id    a CloudResource id     *     * @return <tt>true</tt> if the given ID exists, <tt>false</tt> otherwise     *     * @pre id != null     * @post $none     */    public boolean resourceExist(Integer id) {        if (id == null) {            return false;        }        return resourceExist( id.intValue() );    }    ////////////////////////// PROTECTED METHODS ////////////////////////////    /**     * 处理其他事件     * This method needs to override by a child class for processing     * other events.     * These events are based on tags that are not mentioned in     * {@link #body()} method.     *     * @param ev   a Sim_event object     *     * @pre ev != null     * @post $none     */    protected void processOtherEvent(SimEvent ev) {        if (ev == null) {            Log.printLine("CloudInformationService.processOtherEvent(): " +                    "Unable to handle a request since the event is null.");            return;        }        Log.printLine("CloudInformationSevice.processOtherEvent(): " +                "Unable to handle a request from " +                CloudSim.getEntityName( ev.getSource() ) +                " with event tag = " + ev.getTag() );    }    /**     * Notifies the registered entities about the end of simulation.     * This method should be overridden by the child class     */    protected void processEndSimulation() {        // this should be overridden by the child class    }    //////////////////// End of PROTECTED METHODS ///////////////////////////    /**     * 检查某个ID实体是否在列表中     * Checks for a list for a particular resource id.     *     * @param list   list of hostList     * @param id     a resource ID     *     * @return true if a resource is in the list, otherwise false     *     * @pre list != null     * @pre id > 0     * @post $none     */    private boolean checkResource(Collection<Integer> list, int id) {        boolean flag = false;        if (list == null || id < 0) {            return flag;        }        Integer obj = null;        Iterator<Integer> it = list.iterator();        // a loop to find the match the resource id in a list        while ( it.hasNext() )        {            obj = it.next();            if (obj.intValue() == id)            {                flag = true;                break;            }        }        return flag;    }    /**     * shutdownEntity方法调用，CIS关闭表示仿真结束，通知其他实体     * Tells all registered entities the end of simulation.     *     * @pre $none     * @post $none     */    private void notifyAllEntity() {        Log.printLine(super.getName() +                ": Notify all CloudSim entities for shutting down.");        signalShutdown(resList);        signalShutdown(gisList);        // reset the values        resList.clear();        gisList.clear();    }    /**     * 向列表中各个实体发送END_OF_SIMULATION消息,该消息延迟时间为0     * Sends a signal to all entity IDs mentioned in the given list.     *     * @param list  List storing entity IDs     *     * @pre list != null     * @post $none     */    protected void signalShutdown(Collection<Integer> list) {        // checks whether a list is empty or not        if (list == null) {            return;        }        Iterator<Integer> it = list.iterator();        Integer obj = null;        int id = 0;     // entity ID        // Send END_OF_SIMULATION event to all entities in the list        while (it.hasNext()) {            obj = it.next();            id = obj.intValue();            super.send(id, 0L, CloudSimTags.END_OF_SIMULATION);        }    }} // end class