001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *  http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.directory.api.util;
020
021
022/**
023 * A class containing static methods used to serialize and deserialize base types
024 * 
025 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
026 */
027public class Serialize
028{
029    public final static byte TRUE = 0x01;
030    public final static byte FALSE = 0x00;
031
032
033    /**
034     * Write an integer into a buffer at a given position
035     * 
036     * @param value The value to serialize
037     * @param buffer The buffer to store the value into
038     * @param pos The position where we serialize the integer
039     */
040    public static int serialize( int value, byte[] buffer, int pos )
041    {
042        if ( buffer.length - pos < 4 )
043        {
044            throw new ArrayIndexOutOfBoundsException();
045        }
046
047        buffer[pos++] = ( byte ) ( ( value >>> 24 ) & 0xFF );
048        buffer[pos++] = ( byte ) ( ( value >>> 16 ) & 0xFF );
049        buffer[pos++] = ( byte ) ( ( value >>> 8 ) & 0xFF );
050        buffer[pos++] = ( byte ) ( ( value >>> 0 ) & 0xFF );
051
052        return pos;
053    }
054
055
056    /**
057     * Write a byte[] into a buffer at a given position
058     * 
059     * @param value The value to serialize
060     * @param buffer The buffer to store the value into
061     * @param pos The position where we serialize the byte[]
062     */
063    public static int serialize( byte[] value, byte[] buffer, int pos )
064    {
065        if ( buffer.length - pos < 4 + value.length )
066        {
067            throw new ArrayIndexOutOfBoundsException();
068        }
069
070        buffer[pos++] = ( byte ) ( ( value.length >>> 24 ) & 0xFF );
071        buffer[pos++] = ( byte ) ( ( value.length >>> 16 ) & 0xFF );
072        buffer[pos++] = ( byte ) ( ( value.length >>> 8 ) & 0xFF );
073        buffer[pos++] = ( byte ) ( ( value.length >>> 0 ) & 0xFF );
074
075        System.arraycopy( value, 0, buffer, pos, value.length );
076
077        return pos + value.length;
078    }
079
080
081    /**
082     * Read an integer from a buffer at a given position
083     * 
084     * @param buffer The buffer containing the serialized integer
085     * @param pos The position from which we will read an integer
086     * @return the deserialized integer
087     */
088    public static int deserializeInt( byte[] buffer, int pos )
089    {
090        if ( buffer.length - pos < 4 )
091        {
092            throw new ArrayIndexOutOfBoundsException();
093        }
094
095        return ( buffer[pos] << 24 ) + ( buffer[pos + 1] << 16 ) + ( buffer[pos + 2] << 8 ) + ( buffer[pos + 3] << 0 );
096    }
097
098
099    /**
100     * Read a byte[] from a buffer at a given position
101     * 
102     * @param buffer The buffer containing the serialized byte[]
103     * @param pos The position from which we will read a byte[]
104     * @return the deserialized byte[]
105     */
106    public static byte[] deserializeBytes( byte[] buffer, int pos )
107    {
108        if ( buffer.length - pos < 4 )
109        {
110            throw new ArrayIndexOutOfBoundsException();
111        }
112
113        int len = deserializeInt( buffer, pos );
114        pos += 4;
115
116        if ( len > 0 )
117        {
118            if ( buffer.length - pos < len )
119            {
120                throw new ArrayIndexOutOfBoundsException();
121            }
122
123            byte[] result = new byte[len];
124
125            System.arraycopy( buffer, pos, result, 0, len );
126
127            return result;
128        }
129        else
130        {
131            return Strings.EMPTY_BYTES;
132        }
133    }
134
135
136    /**
137     * Read a boolean from a buffer at a given position
138     * 
139     * @param buffer The buffer containing the serialized boolean
140     * @param pos The position from which we will read a boolean
141     * @return the deserialized boolean
142     */
143    public static boolean deserializeBoolean( byte[] buffer, int pos )
144    {
145        if ( buffer.length - pos < 1 )
146        {
147            throw new ArrayIndexOutOfBoundsException();
148        }
149
150        byte value = buffer[pos];
151
152        return ( value != 0x00 );
153    }
154}