/*

 * Copyright (c) 2002, 2003, 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.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.jmx.snmp;

/**

 * This engine is conformant with the RFC 2571. It is the main object within an SNMP entity (agent, manager...).

 * To an engine is associated an {@link SnmpEngineId}.

 * Engine instantiation is based on a factory {@link com.sun.jmx.snmp.SnmpEngineFactory  SnmpEngineFactory}.

 * When an <CODE> SnmpEngine </CODE> is created, a User based Security Model (USM) is initialized. The security configuration is located in a text file.

 * The text file is read when the engine is created.

 * <p>Note that the engine is not used when the agent is SNMPv1/SNMPv2 only.

<P> The USM configuration text file is remotely updatable using the USM Mib.</P>

<P> User that are configured in the Usm text file are nonVolatile. </P>

<P> Usm Mib userEntry supported storage type values are : volatile or nonVolatile only. Other values are rejected and a wrongValue is returned) </P>

<ul>

<li> volatile means that user entry is not flushed in security file </li>

<li> nonVolatile means that user entry is flushed in security file </li>

<li> If a nonVolatile row is set to be volatile, it will be not flushed in the file </li>

<li>If a volatile row created from the UsmMib is set to nonVolatile, it will be flushed in the file (if the file exist and is writable otherwise an inconsistentValue is returned)</li>

</ul>

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

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

 * @since 1.5

 */

public interface SnmpEngine {

    /**

     * Gets the engine time in seconds. This is the time from the last reboot.

     * @return The time from the last reboot.

     */

    public int getEngineTime();

    /**

     * Gets the engine Id. This is unique for each engine.

     * @return The engine Id object.

     */

    public SnmpEngineId getEngineId();

    /**

     * Gets the engine boot number. This is the number of time this engine has rebooted. Each time an <CODE>SnmpEngine</CODE> is instantiated, it will read this value in its Lcd, and store back the value incremented by one.

     * @return The engine's number of reboot.

     */

    public int getEngineBoots();

    /**

     * Gets the Usm key handler.

     * @return The key handler.

     */

    public SnmpUsmKeyHandler getUsmKeyHandler();

}