/* * 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 * * $Id: FilterGridlet.java,v 1.3 2005/03/10 04:35:17 anthony Exp $ */package gridsim.filter;import gridsim.Gridlet;import eduni.simjava.Sim_predicate;import eduni.simjava.Sim_event;/** * Look for a specific incoming event that carries a <tt>Gridlet</tt> object. * <br><br> * * This class is used by {@link eduni.simjava.Sim_system} * to select or filter an event already present in the entity's deferred queue * (incoming buffer), or used to selectively wait for a future event. * <br> <br> * * <b>An example on how to use this class:</b><br> * Imagine we have a scenario where <tt>Entity_A</tt> sends one or more events * to <tt>Entity_B</tt> with different tag names and data objects.<br> * <tt>Entity_B</tt> wants to get an event that contains a specific * <tt>Gridlet</tt> object in this example. <br> * Therefore, inside the <tt>Entity_B</tt> code:<br> <br> * * <code> * * &nbsp;&nbsp; ... // other code <br><br> * &nbsp;&nbsp; int gridletID = 1;   // e.g. only look for Gridlet #1<br> * &nbsp;&nbsp; Sim_event ev = new Sim_event(); <br> * &nbsp;&nbsp; FilterGridlet filter = new FilterGridlet(gridletID); <br> * <br> * &nbsp;&nbsp; // get an incoming event that matches a given gridlet id <br> * &nbsp;&nbsp; super.sim_get_next(filter, ev); <br> * <br> * &nbsp;&nbsp; // get the matching event data <br> * &nbsp;&nbsp; Gridlet gl = (Gridlet) ev.get_data(); <br> * </code> * <br><br> * * <b>NOTE:</b> * <ul> * <li> both <tt>Entity_A</tt> and <tt>Entity_B</tt> must be an instance of *      {@link eduni.simjava.Sim_entity} class. * <li> <tt>Entity_A</tt> <b>must</b> send the correct data object to *      <tt>Entity_B</tt> for this type of filtering. <br> *      The event data object <b>must</b> be of type <tt>Gridlet</tt>. * <li> if no incoming events match the given condition, then *      {@link eduni.simjava.Sim_entity#sim_get_next(Sim_predicate, Sim_event)} *      method will wait indefinitely. * </ul> * * @author       Anthony Sulistio * @since        GridSim Toolkit 3.2 * @invariant $none */public class FilterGridlet extends Sim_predicate{    private int tag_;           // a tag name    private int gridletID_;     // a gridlet ID    private int userID_;        // a user ID that owns this Gridlet    private int resID_;         // a resource ID that executes this Gridlet    private int searchType_;    // type of filtering (see below)    private final int FIND_GRIDLET_ID = 1;    private final int FIND_GRIDLET_WITH_RES_ID = 2;    private final int FIND_GRIDLET_WITH_USER_AND_RES_ID = 3;    /**     * Finds a Gridlet in the incoming buffer of an entity that matches with     * the given three constraints: gridlet id, user id and resource id.     *     * @param gridletID   a gridlet id     * @param userID      a user id that owns this Gridlet object     * @param resID       a resource id that executes this Gridlet object     * @pre $none     * @post $none     */    public FilterGridlet(int gridletID, int userID, int resID)    {        gridletID_ = gridletID;        userID_ = userID;        resID_ = resID;        searchType_ = FIND_GRIDLET_WITH_USER_AND_RES_ID;        tag_ = -1;    }    /**     * Finds a Gridlet in the incoming buffer of an entity that matches with     * the given two constraints: gridlet id and resource id.     *     * @param gridletID   a gridlet id     * @param resID       a resource id that executes this Gridlet object     * @pre $none     * @post $none     */    public FilterGridlet(int gridletID, int resID)    {        gridletID_ = gridletID;        userID_ = -1;        resID_ = resID;        searchType_ = FIND_GRIDLET_WITH_RES_ID;        tag_ = -1;    }    /**     * Finds a Gridlet in the incoming buffer of an entity that matches with     * a given gridlet id.     *     * @param gridletID     * @pre $none     * @post $none     */    public FilterGridlet(int gridletID)    {        gridletID_ = gridletID;        userID_ = -1;        resID_ = -1;        searchType_ = FIND_GRIDLET_ID;        tag_ = -1;    }    /**     * Sets the event matching tag name     * @param tag   a matching event tag name (must be 0 or a positive integer)     * @return <tt>true</tt> if it is successful, <tt>false</tt> otherwise.     * @pre $none     * @post $none     */    public boolean setTag(int tag)    {        if (tag < 0) {            return false;        }        tag_ = tag;        return true;    }    /**     * Checks whether an event matches the required constraints or not.<br>     * NOTE: This method is not used directly by the user. Instead, it is     * called by {@link eduni.simjava.Sim_system}.     *     * @param ev    an incoming event to compare with     * @return <tt>true</tt> if an event matches, <tt>false</tt> otherwise     * @pre ev != null     * @post $none     */    public boolean match(Sim_event ev)    {        if (ev == null) {            return false;        }        boolean result = false;        try        {            if ( tag_ == -1 || tag_ == ev.get_tag() )            {                Object obj = ev.get_data();                if (obj instanceof Gridlet)                {                    Gridlet gl = (Gridlet) obj;                    result = findGridlet(gl);                }            }        }        catch (Exception e) {            result = false;        }        return result;    }    /**     * Finds a Gridlet in an event that matches a given condition     * @param gl    a Gridlet object     * @return <tt>true</tt> if found, <tt>false</tt> otherwise     * @pre gl != null     * @post $none     */    private boolean findGridlet(Gridlet gl)    {        if (gl == null) {            return false;        }        boolean result = false;        int glID = gl.getGridletID();        int glResID = -1;        switch(searchType_)        {            // find a Gridlet that matches with a given id            case FIND_GRIDLET_ID:                if (glID == gridletID_) {                    result = true;                }                break;            // find a Gridlet that matches with a given id also            // user and resource id            case FIND_GRIDLET_WITH_USER_AND_RES_ID:                int glUserID = gl.getUserID();                glResID = gl.getResourceID();                if (glID == gridletID_ && glUserID == userID_ &&                    glResID == resID_)                {                    result = true;                }                break;            // find a Gridlet that matches with a given id and its resource id            case FIND_GRIDLET_WITH_RES_ID:                glResID = gl.getResourceID();                if (glID == gridletID_ && glResID == resID_) {                    result = true;                }                break;            default:                result = false;                break;        }        return result;    }} // end class