ByteArrayBuffer.java revision 069490a5ca2fd1988d29daf45d892f47ad665115 
1/*
2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/util/ByteArrayBuffer.java $
3 * $Revision: 496070 $
4 * $Date: 2007-01-14 04:18:34 -0800 (Sun, 14 Jan 2007) $
5 *
6 * ====================================================================
7 * Licensed to the Apache Software Foundation (ASF) under one
8 * or more contributor license agreements.  See the NOTICE file
9 * distributed with this work for additional information
10 * regarding copyright ownership.  The ASF licenses this file
11 * to you under the Apache License, Version 2.0 (the
12 * "License"); you may not use this file except in compliance
13 * with the License.  You may obtain a copy of the License at
14 *
15 *   http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing,
18 * software distributed under the License is distributed on an
19 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
20 * KIND, either express or implied.  See the License for the
21 * specific language governing permissions and limitations
22 * under the License.
23 * ====================================================================
24 *
25 * This software consists of voluntary contributions made by many
26 * individuals on behalf of the Apache Software Foundation.  For more
27 * information on the Apache Software Foundation, please see
28 * <http://www.apache.org/>.
29 *
30 */
31
32package org.apache.http.util;
33
34/**
35 * A resizable byte array.
36 *
37 * @author <a href="mailto:oleg@ural.ru">Oleg Kalnichevski</a>
38 *
39 * @version $Revision: 496070 $
40 *
41 * @since 4.0
42 */
43public final class ByteArrayBuffer  {
44
45    private byte[] buffer;
46    private int len;
47
48    public ByteArrayBuffer(int capacity) {
49        super();
50        if (capacity < 0) {
51            throw new IllegalArgumentException("Buffer capacity may not be negative");
52        }
53        this.buffer = new byte[capacity];
54    }
55
56    private void expand(int newlen) {
57        byte newbuffer[] = new byte[Math.max(this.buffer.length << 1, newlen)];
58        System.arraycopy(this.buffer, 0, newbuffer, 0, this.len);
59        this.buffer = newbuffer;
60    }
61
62    public void append(final byte[] b, int off, int len) {
63        if (b == null) {
64            return;
65        }
66        if ((off < 0) || (off > b.length) || (len < 0) ||
67                ((off + len) < 0) || ((off + len) > b.length)) {
68            throw new IndexOutOfBoundsException();
69        }
70        if (len == 0) {
71            return;
72        }
73        int newlen = this.len + len;
74        if (newlen > this.buffer.length) {
75            expand(newlen);
76        }
77        System.arraycopy(b, off, this.buffer, this.len, len);
78        this.len = newlen;
79    }
80
81    public void append(int b) {
82        int newlen = this.len + 1;
83        if (newlen > this.buffer.length) {
84            expand(newlen);
85        }
86        this.buffer[this.len] = (byte)b;
87        this.len = newlen;
88    }
89
90    public void append(final char[] b, int off, int len) {
91        if (b == null) {
92            return;
93        }
94        if ((off < 0) || (off > b.length) || (len < 0) ||
95                ((off + len) < 0) || ((off + len) > b.length)) {
96            throw new IndexOutOfBoundsException();
97        }
98        if (len == 0) {
99            return;
100        }
101        int oldlen = this.len;
102        int newlen = oldlen + len;
103        if (newlen > this.buffer.length) {
104            expand(newlen);
105        }
106        for (int i1 = off, i2 = oldlen; i2 < newlen; i1++, i2++) {
107            this.buffer[i2] = (byte) b[i1];
108        }
109        this.len = newlen;
110    }
111
112    public void append(final CharArrayBuffer b, int off, int len) {
113        if (b == null) {
114            return;
115        }
116        append(b.buffer(), off, len);
117    }
118
119    public void clear() {
120        this.len = 0;
121    }
122
123    public byte[] toByteArray() {
124        byte[] b = new byte[this.len];
125        if (this.len > 0) {
126            System.arraycopy(this.buffer, 0, b, 0, this.len);
127        }
128        return b;
129    }
130
131    public int byteAt(int i) {
132        return this.buffer[i];
133    }
134
135    public int capacity() {
136        return this.buffer.length;
137    }
138
139    public int length() {
140        return this.len;
141    }
142
143    public byte[] buffer() {
144        return this.buffer;
145    }
146
147    public void setLength(int len) {
148        if (len < 0 || len > this.buffer.length) {
149            throw new IndexOutOfBoundsException();
150        }
151        this.len = len;
152    }
153
154    public boolean isEmpty() {
155        return this.len == 0;
156    }
157
158    public boolean isFull() {
159        return this.len == this.buffer.length;
160    }
161
162}
163