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 * 019 */ 020 package org.apache.directory.shared.ldap.util; 021 022 import org.apache.directory.shared.i18n.I18n; 023 024 025 /** 026 * A dynamically growing byte[]. 027 * 028 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> 029 * @version $Rev$ 030 */ 031 public class ByteBuffer 032 { 033 /** the default initial buffer size */ 034 private static final int DEFAULT_INITIAL_SIZE = 10; 035 036 /** the initial size of the buffer in number of bytes: also increment for allocations */ 037 private final int initialSize; 038 /** the position into the buffer */ 039 private int pos = 0; 040 /** the bytes of the buffer */ 041 private byte[] buf; 042 043 044 public ByteBuffer() 045 { 046 this ( DEFAULT_INITIAL_SIZE ); 047 } 048 049 050 public ByteBuffer( int initialSize ) 051 { 052 if ( initialSize <= 0 ) 053 { 054 throw new IllegalArgumentException( I18n.err( I18n.ERR_04354 ) ); 055 } 056 this.initialSize = initialSize; 057 this.buf = new byte[initialSize]; 058 } 059 060 061 public final void clear() 062 { 063 pos = 0; 064 } 065 066 067 public final int position() 068 { 069 return pos; 070 } 071 072 073 public final int capacity() 074 { 075 return buf.length; 076 } 077 078 079 public final byte get( int ii ) 080 { 081 return buf[ii]; 082 } 083 084 085 /** 086 * Get's the bytes, the backing store for this buffer. Note 087 * that you need to use the position index to determine where 088 * to stop reading from this buffer. 089 */ 090 public final byte[] buffer() 091 { 092 return buf; 093 } 094 095 096 /** 097 * Get's a copy of the bytes used. 098 */ 099 public final byte[] copyOfUsedBytes() 100 { 101 byte[] copy = new byte[pos]; 102 System.arraycopy( buf, 0, copy, 0, pos ); 103 return copy; 104 } 105 106 107 /** 108 * Appends the bytes to this buffer. 109 */ 110 public final void append( byte[] bytes ) 111 { 112 for ( byte b : bytes ) 113 { 114 append( b ); 115 } 116 } 117 118 119 /** 120 * Appends a byte to this buffer. 121 */ 122 public final void append( byte bite ) 123 { 124 if ( pos >= buf.length ) 125 { 126 growBuffer(); 127 } 128 129 buf[pos] = bite; 130 pos++; 131 } 132 133 134 /** 135 * Appends an int to this buffer. WARNING: the int is truncated to 136 * a byte value. 137 */ 138 public final void append( int val ) 139 { 140 if ( pos >= buf.length ) 141 { 142 growBuffer(); 143 } 144 145 buf[pos] = ( byte ) val; 146 pos++; 147 } 148 149 150 private final void growBuffer() 151 { 152 byte[] copy = new byte[buf.length+initialSize]; 153 System.arraycopy( buf, 0, copy, 0, pos ); 154 this.buf = copy; 155 } 156 }