/*

 * Copyright (c) 2003, 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.

 *

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

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package sun.management.snmp.util;

import com.sun.jmx.snmp.SnmpOid;

import java.io.Serializable;

import java.util.Comparator;

import java.util.Arrays;

import java.util.TreeMap;

import java.util.List;

import java.util.Iterator;

import java.lang.ref.WeakReference;

/**

 * This class is used to cache table data.

 **/

public class SnmpCachedData implements SnmpTableHandler {

    /**

     * Compares two SnmpOid.

     **/

    public static final Comparator<SnmpOid> oidComparator =

        new Comparator<SnmpOid>() {

            public int compare(SnmpOid o1, SnmpOid o2) {

                return o1.compareTo(o2);

            }

            public boolean equals(Object o1, Object o2) {

                if (o1 == o2) return true;

                else return o1.equals(o2);

            }

        };

    /**

     * Constructs a new instance of SnmpCachedData. Instances are

     * immutable.

     * @param lastUpdated Time stamp as returned by

     *        {@link System#currentTimeMillis System.currentTimeMillis()}

     * @param indexes The table entry indexes, sorted in ascending order.

     * @param datas   The table datas, sorted according to the

     *                order in <code>indexes</code>: <code>datas[i]</code>

     *                is the data that corresponds to

     *                <code>indexes[i]</code>

     **/

    public SnmpCachedData(long lastUpdated, SnmpOid indexes[],

                          Object  datas[]) {

        this.lastUpdated = lastUpdated;

        this.indexes     = indexes;

        this.datas       = datas;

    }

    /**

     * Constructs a new instance of SnmpCachedData. Instances are

     * immutable.

     * @param lastUpdated Time stamp as returned by

     *        {@link System#currentTimeMillis System.currentTimeMillis()}

     * @param indexMap The table indexed table data, sorted in ascending

     *                 order by {@link #oidComparator}. The keys must be

     *                 instances of {@link SnmpOid}.

     **/

    public SnmpCachedData(long lastUpdated, TreeMap<SnmpOid, Object> indexMap) {

        this(lastUpdated, indexMap, true);

    }

    /**

     * Constructs a new instance of SnmpCachedData. Instances are

     * immutable.

     * @param lastUpdated Time stamp as returned by

     *        {@link System#currentTimeMillis System.currentTimeMillis()}

     * @param indexMap The table indexed table data, sorted in ascending

     *                 order by {@link #oidComparator}. The keys must be

     *                 instances of {@link SnmpOid}.

     **/

    public SnmpCachedData(long lastUpdated, TreeMap<SnmpOid, Object> indexMap,

                          boolean b) {

        final int size = indexMap.size();

        this.lastUpdated = lastUpdated;

        this.indexes     = new SnmpOid[size];

        this.datas       = new Object[size];

        if(b) {

            indexMap.keySet().toArray(this.indexes);

            indexMap.values().toArray(this.datas);

        } else

            indexMap.values().toArray(this.datas);

    }

    /**

     * Time stamp as returned by

     * {@link System#currentTimeMillis System.currentTimeMillis()}

     **/

    public final long    lastUpdated;

    /**

     * The table entry indexes, sorted in ascending order.

     **/

    public final SnmpOid indexes[];

    /**

     * The table datas, sorted according to the

     * order in <code>indexes</code>: <code>datas[i]</code>

     * is the data that corresponds to <code>indexes[i]</code>

     **/

    public final Object  datas[];

    /**

     * The position of the given <var>index</var>, as returned by

     * <code>java.util.Arrays.binarySearch()</code>

     **/

    public final int find(SnmpOid index) {

        return Arrays.binarySearch(indexes,index,oidComparator);

    }

    // SnmpTableHandler.getData()

    public  Object getData(SnmpOid index) {

        final int pos = find(index);

        if ((pos < 0)||(pos >= datas.length)) return null;

        return datas[pos];

    }

    // SnmpTableHandler.getNext()

    public  SnmpOid getNext(SnmpOid index) {

        if (index == null) {

            if (indexes.length>0) return indexes[0];

            else return null;

        }

        final int pos = find(index);

        if (pos > -1) {

            if (pos < (indexes.length -1) ) return indexes[pos+1];

            else return null;

        }

        final int insertion = -pos -1;

        if ((insertion > -1) && (insertion < indexes.length))

            return indexes[insertion];

        else return null;

    }

    // SnmpTableHandler.contains()

    public  boolean contains(SnmpOid index) {

        final int pos = find(index);

        return ((pos > -1)&&(pos < indexes.length));

    }

}