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