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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 SnmpEngine to store and retrieve data.
 SnmpLcd manages the Lcds needed by every SnmpModel. It is possible to add and remove SnmpModelLcd.
This API is a Sun Microsystems internal API  and is subject
to change without notice.
Since:
1.5/**
 * 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.
Returns:
The number of reboots or -1 if the information is not present in the Lcd./**
     * 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.
Returns:
The engine Id or null if the information is not present in the Lcd./**
     * 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.
Params:
i – Reboot number./**
     * Persists the number of reboots.
     * @param i Reboot number.
     */
    public abstract void storeEngineBoots(int i);

    
Persists the engine Id.
Params:
id – The engine Id./**
     * Persists the engine Id.
     * @param id The engine Id.
     */
    public abstract void  storeEngineId(SnmpEngineId id);
    
Adds an Lcd model.
Params:
sys – The subsytem managing the model.
id – The model Id.
lcd – The Lcd model./**
     * 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.
Params:
sys – The subsytem managing the model.
id – The model Id./**
     * 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.
Params:
sys – The subsytem managing the model
id – The model Id.
Returns:
The Lcd model or null if no Lcd model were found./**
     * 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);
    }
}