abstractrc.java

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/*
 * 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 eduni.simjava.*;
import gridsim.*;
import gridsim.datagrid.*;
import gridsim.net.*;

/**
 * An abstract class for the functionality of a Replica Catalogue (RC) entity.
 * The RC entity is a core component of every Data Grid system. The
 * function of a RC is to store the information (metadata) about files and to
 * provide mapping between a filename and its physical location(s).
 * <br>
 * The RC does not have to be a single entity in a Data Grid system.
 * It can also be composed of several distributed components, which, by
 * switching the information among them, provide a transparent service to
 * the users and resources.
 * <br>
 * Currently, GridSim allows two possible catalogue models:
 * <ul>
 * <li> Centralized Model. <br>
 * There is only one RC component in a Data Grid system that handles all
 * registrations and queries sent by resources and users.
 * Hence, the RC maps a filename to a list of resources that stores this file.
 * <br><br>
 * <li> Hierarchical Model. <br>
 * The hierarchical RC model is constructed as a catalogue tree.
 * In this model, some information are stored in the root of the catalogue
 * tree, and the rest in the leaves.
 * </ul>
 * <br>
 * Common functionalities of a RC is encapsulated in this class, an
 * abstract parent class for both {@link gridsim.datagrid.index.TopRegionalRC}
 * and {@link gridsim.datagrid.index.RegionalRC}.
 * The {@link gridsim.datagrid.index.TopRegionalRC} class acts as a
 * centralized RC or a root RC in a hierarchical model. In constrast, the
 * {@link gridsim.datagrid.index.RegionalRC} class represents a local RC
 * and/or a leaf RC in a hierarchical model.
 * Therefore, creating a new RC model can be done by extending this
 * class and implementing the abstract methods.
 *
 * @author  Uros Cibej and Anthony Sulistio
 * @since   GridSim Toolkit 4.0
 */
public abstract class AbstractRC extends GridSimCore {

    /** A flag that denotes whether this entity is located inside a resource
     * or not
     */
    protected boolean localRC_;     // local RC or not

    /** A resource ID that hosts this RC entity (if applicable) */
    protected int resourceID_;      // resource ID that hosts this RC

    private int gisID_;             // GIS entity ID


    /**
     * Creates a new <b>local</b> Replica Catalogue (RC) entity.
     * This constructor should be used if you want this RC entity to be inside
     * a resource's domain, hence known as <i>a Local RC</i>.
     * As a consequence, this entity uses the resource ID and I/O port for
     * indentification.
     * <br>
     * The Local RC is responsible for indexing available files on the
     * resource only. It also handles users