/*
* 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) 2009-2012, The University of Melbourne, Australia
*/
package org.cloudbus.cloudsim.core;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import org.cloudbus.cloudsim.Log;
/**
* A Cloud Information Service (CIS) is an entity that provides cloud resource registration,
* indexing and discovery services. The Cloud hostList tell their readiness to process Cloudlets by
* registering themselves with this entity. 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. This class will be created by CloudSim upon
* initialisation of the simulation. Hence, do not need to worry about creating an object of this
* class.
*
* @author Manzur Murshed
* @author Rajkumar Buyya
* @since CloudSim 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
* @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>();
}
/**
* Starts the CloudInformationService entity.
*/
@Override
public void startEntity() {
}
/**
* Processes events scheduled for this entity.
*
* @param ev the event to be handled.
* @see SimEntity#processEvent(SimEvent)
*/
@Override
public 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;
}
}
/**
* Shutdowns the CloudInformationService.
*/
@Override
public 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;
}
/**
* 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());
}
/**
* 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;
}
/**
* 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 ////////////////////////////
/**
* 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 ///////////////////////////
/**
* 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;
}
/**
* 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();
}
/**
* 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);
}
}
}