topregionalrc.java

中間件開發详细说明：清华大学J2EE教程讲义（ppt）-Tsinghua University J2EE tutorial lectures (ppt) [上载源码成为会员下载此源码] [成为VIP会

/*
 * Title:        GridSim Toolkit
 * Description:  GridSim (Grid Simulation) Toolkit for Modeling and Simulation
 *               of Parallel and Distributed Systems such as Clusters and Grids
 * Licence:      GPL - http://www.gnu.org/copyleft/gpl.html
 */
package gridsim.datagrid.index;

import java.util.*;

import eduni.simjava.*;
import gridsim.datagrid.*;
import gridsim.net.Link;
import gridsim.*;
import gridsim.datagrid.filter.Filter;


/**
 * This class acts as a centralized RC or a root RC in a hierarchical model.
 * It is responsible for generating a unique ID for each file name.
 * Hence, the full name of the file will be "filename+uniqueID"
 * when you use {@link gridsim.datagrid.DataGridUser#getFullFilename(String)}
 *
 * @author  Uros Cibej and Anthony Sulistio
 * @since   GridSim Toolkit 4.0
 * @see gridsim.datagrid.index.RegionalRC
 */
public class TopRegionalRC extends AbstractRC
{
    private Hashtable catalogueHash_;   // storing replicas
    private Hashtable attrHash_;        // storing file attributes
    private int lastUniqueID;           //  generate a uniqueID


    /** Default name for this RC entity, which is "GridSim_TopRC".
     *  NOTE: This default name is useful when a user forgets to tell the
     * {@link gridsim.datagrid.DataGridUser} or
     * {@link gridsim.datagrid.DataGridResource} entity about the RC id.
     */
    public static final String DEFAULT_NAME = "GridSim_TopRC";

    /**
     * Creates a new Replica Catalogue (RC) entity.
     * @param name  this entity name
     * @param link  the link that this GridSim entity will use to
     *              communicate with other GridSim or Network entities.
     * @throws Exception    This happens when one of the input parameters is
     *                      invalid.
     */
    public TopRegionalRC(String name, Link link) throws Exception
    {
        super(name, link);
        init();
    }

    /**
     * Creates a new Replica Catalogue (RC) entity with a default name.
     * @param link  the link that this GridSim entity will use to
     *              communicate with other GridSim or Network entities.
     * @throws Exception    This happens when the network link is null
     */
    public TopRegionalRC(Link link) throws Exception
    {
        super(TopRegionalRC.DEFAULT_NAME, link);
        init();
    }

    /** Initialization of all atttributes */
    private void init()
    {
        catalogueHash_ = new Hashtable();
        attrHash_ = new Hashtable();
        lastUniqueID = 0;
    }


    //-------MAIN METHOD FOR HANDLING REQUESTS/EVENTS--------------

    /**
     * Processes an incoming request that uses a user-defined tag. This method
     * is useful for creating a new RC entity.
     * @param ev  a Sim_event object (or an incoming event or request)
     * @return <tt>true</tt> if successful, <tt>false</tt> otherwise
     */
    protected boolean processOtherEvent(Sim_event ev)
    {
        boolean result = true;
        switch ( ev.get_tag() )
        {
            //-----------REPLICA MANAGER REQUESTS--------
            case DataGridTags.CTLG_ADD_MASTER:
                processAddMaster(ev);
                break;

            case DataGridTags.CTLG_DELETE_MASTER:
                processDeleteMaster(ev);
                break;

            case DataGridTags.CTLG_ADD_REPLICA:
                processAddReplica(ev);
                break;

            case DataGridTags.CTLG_DELETE_REPLICA:
                processDeleteReplica(ev);
                break;

            //-------USER REQUESTS---------------
            case DataGridTags.CTLG_GET_FILE_ATTR:
                processFileAttrRequest(ev);
                break;

            case DataGridTags.CTLG_GET_REPLICA:
                processGetReplica(ev);
                break;

            case DataGridTags.CTLG_GET_REPLICA_LIST:
                processGetReplicaList(ev);
                break;

            case DataGridTags.CTLG_FILTER:
                processFilterFiles(ev);
                break;

            default:
                System.out.println(super.get_name() +
                    ".processOtherEvent(): Warning - unknown tag = "+ev.get_tag());
                result = false;
                break;
        }

        return result;
    }


    //  -----------------PROCESS REPLICA MANAGER REQUESTS------------

    /**
     * Manages the request for adding a replica to the catalogue. It receives an
     * event with the name of the file and the <code>resID</code> where this
     * file is located.
     * <br>
     * If the catalogue already contains an entry for this file name (i.e.
     * the master file is already registered) than adds the <code>resID</code>
     * to the list of resources with that file.
     * <br>
     * If there is no entry in the catalogue for this file name, then
     * returns an error to the resource.
     *
     * @param ev    a Sim_event object
     */
    private void processAddReplica(Sim_event ev)
    {
        if (ev == null) {
            return;
        }

        Object[] obj = (Object[]) ev.get_data();
        if (obj == null)
        {
            System.out.println(super.get_name() +
                    ".processAddReplica(): replica is null");
            return;
        }

        String name = (String) obj[0];      // get file name
        Integer resID = (Integer) obj[1];   // get resource id

        int result = DataGridTags.CTLG_ADD_REPLICA_SUCCESSFUL;
        try
        {
            /*****  // DEBUG
            System.out.println(super.get_name() +
                ".processAddReplica(): top RC for " + name);
            *****/

            // if this replica name is a new entry
            ArrayList list = (ArrayList) catalogueHash_.get(name);
            if (list == null)
            {
                /*****  // DEBUG
                System.out.println(super.get_name() +
                    ".processAddReplica(): empty list --> new catalogue for " +
                    name);
                *****/

                list = new ArrayList();   // create a new list
                list.add(resID);          // put resource ID into this list
                catalogueHash_.put(name, list);     // add into catalogue
            }
            else
            {
                list.add(resID);

                /*****  // DEBUG
                System.out.println(super.get_name() +
                    ".processAddReplica(): adds into the list for " + name);
                *****/
            }
        }
        catch (Exception e) {
            result = DataGridTags.CTLG_ADD_REPLICA_ERROR;
        }


        /*****  // DEBUG
        System.out.println(super.get_name() +
                ".processAddReplica(): sends the result back to " +
                GridSim.getEntityName((Integer) obj[1]));
        *****/

        sendMessage(name, DataGridTags.CTLG_ADD_REPLICA_RESULT,
                    result, resID.intValue() );
    }

    /**
     * Manages the request for deleting a replica from the Replica Catalogue.
     * If there is no entry for the filename in the catalogue, then return
     * an error.
     * Otherwise, delete the entry from the catalogue and send a message to
     * the lower level catalogue/or to the resource.
     *
     * @param ev    a Sim_event object
     */
    private void processDeleteReplica(Sim_event ev)
    {
        if (ev == null) {
            return;
        }

        Object[] obj = (Object[]) ev.get_data();
        if (obj == null)
        {
            System.out.println(super.get_name() +
                    ".processDeleteReplica(): no object is found");
            return;
        }

        String name = (String) obj[0];      // get file name
        Integer resID = (Integer) obj[1];   // get resource id

        int msg = DataGridTags.CTLG_DELETE_REPLICA_SUCCESSFUL;
        try
        {

            int event = DataGridTags.CTLG_DELETE_REPLICA;
            ArrayList list = (ArrayList) catalogueHash_.get(name);
            if (list != null && list.size() > 1) {
                 if (list.remove(resID) == false) {
                    msg = DataGridTags.CTLG_DELETE_REPLICA_ERROR_DOESNT_EXIST;
                }
            }
            else{
                msg = DataGridTags.CTLG_DELETE_REPLICA_ERROR_DOESNT_EXIST;
            }

        }
        catch (Exception e) {
            msg = DataGridTags.CTLG_DELETE_REPLICA_ERROR;
        }

        sendMessage(name, DataGridTags.CTLG_DELETE_REPLICA_RESULT, msg,
                    resID.intValue() );
    }

    /**
     * Registers a master file into the Replica Catalogue.
     * The method is similar to {@link #processAddReplica(Sim_event)}.
     * However, in this method, this file is known as
     * "name+uniqueID", e.g. test4 (name is "test" and uniqueID is "4").
     *
     * @param ev    a Sim_event object
     */
    private void processAddMaster(Sim_event ev)
    {
        if (ev == null) {
            return;
        }

        int result = -1;
        Object[] data = (Object[]) ev.get_data();
        if (data == null)
        {
            System.out.println(super.get_name() +
                    ".processAddMaster(): master file name is null");
            return;
        }

        String filename = (String) data[0];             // file name
        FileAttribute attr = (FileAttribute) data[1];   // file attribute
        Integer resourceID = (Integer) data[2];                 // resource ID
        int uniqueID = -1;

        try
        {
            uniqueID = createUniqueID(filename); // create a unique file ID
            result = DataGridTags.CTLG_ADD_MASTER_SUCCESSFUL;

            // put the master file attribute into the catalogue
            ArrayList list = new ArrayList();
            list.add(resourceID);

            catalogueHash_.put(filename + uniqueID, list);
            attrHash_.put(filename + uniqueID, attr);

            /*****  // DEBUG
            System.out.println(super.get_name() +
                ".processAddMaster(): " + filename + " --> id = " + uniqueID);
            *****/
        }
        catch (Exception e) {
            result = DataGridTags.CTLG_ADD_MASTER_ERROR;
        }

        // sends the result back to sender
        data = new Object[3];
        data[0] = filename;
        data[1] = new Integer(uniqueID);
        data[2] = new Integer(result);