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 * Copyright (c) 2001, 2006, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

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package com.sun.jmx.snmp.internal;

import java.util.Hashtable;

import com.sun.jmx.snmp.SnmpEngineId;

import com.sun.jmx.snmp.SnmpUnknownModelLcdException;

import com.sun.jmx.snmp.SnmpUnknownSubSystemException;

/**

 * Class to extend in order to develop a customized Local Configuration Datastore. The Lcd is used by the <CODE>SnmpEngine</CODE> to store and retrieve data.

 *<P> <CODE>SnmpLcd</CODE> manages the Lcds needed by every {@link com.sun.jmx.snmp.internal.SnmpModel SnmpModel}. It is possible to add and remove {@link com.sun.jmx.snmp.internal.SnmpModelLcd SnmpModelLcd}.</P>

 * <p><b>This API is a Sun Microsystems internal API  and is subject

 * to change without notice.</b></p>

 * @since 1.5

 */

public abstract class SnmpLcd {

    class SubSysLcdManager {

        private Hashtable<Integer, SnmpModelLcd> models =

                new Hashtable<Integer, SnmpModelLcd>();

        public void addModelLcd(int id,

                                SnmpModelLcd usmlcd) {

            models.put(new Integer(id), usmlcd);

        }

        public SnmpModelLcd getModelLcd(int id) {

            return models.get(new Integer(id));

        }

        public SnmpModelLcd removeModelLcd(int id) {

            return models.remove(new Integer(id));

        }

    }

    private Hashtable<SnmpSubSystem, SubSysLcdManager> subs =

            new Hashtable<SnmpSubSystem, SubSysLcdManager>();

    /**

     * Returns the number of time the engine rebooted.

     * @return The number of reboots or -1 if the information is not present in the Lcd.

     */

    public abstract int getEngineBoots();

    /**

     * Returns the engine Id located in the Lcd.

     * @return The engine Id or null if the information is not present in the Lcd.

     */

    public abstract String getEngineId();

    /**

     * Persists the number of reboots.

     * @param i Reboot number.

     */

    public abstract void storeEngineBoots(int i);

    /**

     * Persists the engine Id.

     * @param id The engine Id.

     */

    public abstract void  storeEngineId(SnmpEngineId id);

    /**

     * Adds an Lcd model.

     * @param sys The subsytem managing the model.

     * @param id The model Id.

     * @param lcd The Lcd model.

     */

    public void addModelLcd(SnmpSubSystem sys,

                            int id,

                            SnmpModelLcd lcd) {

        SubSysLcdManager subsys = subs.get(sys);

        if( subsys == null ) {

            subsys = new SubSysLcdManager();

            subs.put(sys, subsys);

        }

        subsys.addModelLcd(id, lcd);

    }

     /**

     * Removes an Lcd model.

     * @param sys The subsytem managing the model.

     * @param id The model Id.

     */

    public void removeModelLcd(SnmpSubSystem sys,

                                int id)

        throws SnmpUnknownModelLcdException, SnmpUnknownSubSystemException {

        SubSysLcdManager subsys = subs.get(sys);

        if( subsys != null ) {

            SnmpModelLcd lcd = subsys.removeModelLcd(id);

            if(lcd == null) {

                throw new SnmpUnknownModelLcdException("Model : " + id);

            }

        }

        else

            throw new SnmpUnknownSubSystemException(sys.toString());

    }

    /**

     * Gets an Lcd model.

     * @param sys The subsytem managing the model

     * @param id The model Id.

     * @return The Lcd model or null if no Lcd model were found.

     */

    public SnmpModelLcd getModelLcd(SnmpSubSystem sys,

                                    int id) {

        SubSysLcdManager subsys = subs.get(sys);

        if(subsys == null) return null;

        return subsys.getModelLcd(id);

    }

}