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1   /*
2    * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  /*
27   * This file is available under and governed by the GNU General Public
28   * License version 2 only, as published by the Free Software Foundation.
29   * However, the following notice accompanied the original version of this
30   * file:
31   *
32   * ASM: a very small and fast Java bytecode manipulation framework
33   * Copyright (c) 2000-2007 INRIA, France Telecom
34   * All rights reserved.
35   *
36   * Redistribution and use in source and binary forms, with or without
37   * modification, are permitted provided that the following conditions
38   * are met:
39   * 1. Redistributions of source code must retain the above copyright
40   *    notice, this list of conditions and the following disclaimer.
41   * 2. Redistributions in binary form must reproduce the above copyright
42   *    notice, this list of conditions and the following disclaimer in the
43   *    documentation and/or other materials provided with the distribution.
44   * 3. Neither the name of the copyright holders nor the names of its
45   *    contributors may be used to endorse or promote products derived from
46   *    this software without specific prior written permission.
47   *
48   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
49   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
50   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
51   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
52   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
53   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
54   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
55   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
56   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
57   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
58   * THE POSSIBILITY OF SUCH DAMAGE.
59   */
60  package com.sun.xml.internal.ws.org.objectweb.asm;
61  
62  /**
63   * A dynamically extensible vector of bytes. This class is roughly equivalent to
64   * a DataOutputStream on top of a ByteArrayOutputStream, but is more efficient.
65   *
66   * @author Eric Bruneton
67   */
68  public class ByteVector {
69  
70      /**
71       * The content of this vector.
72       */
73      byte[] data;
74  
75      /**
76       * Actual number of bytes in this vector.
77       */
78      int length;
79  
80      /**
81       * Constructs a new {@link ByteVector ByteVector} with a default initial
82       * size.
83       */
84      public ByteVector() {
85          data = new byte[64];
86      }
87  
88      /**
89       * Constructs a new {@link ByteVector ByteVector} with the given initial
90       * size.
91       *
92       * @param initialSize the initial size of the byte vector to be constructed.
93       */
94      public ByteVector(final int initialSize) {
95          data = new byte[initialSize];
96      }
97  
98      /**
99       * Puts a byte into this byte vector. The byte vector is automatically
100      * enlarged if necessary.
101      *
102      * @param b a byte.
103      * @return this byte vector.
104      */
105     public ByteVector putByte(final int b) {
106         int length = this.length;
107         if (length + 1 > data.length) {
108             enlarge(1);
109         }
110         data[length++] = (byte) b;
111         this.length = length;
112         return this;
113     }
114 
115     /**
116      * Puts two bytes into this byte vector. The byte vector is automatically
117      * enlarged if necessary.
118      *
119      * @param b1 a byte.
120      * @param b2 another byte.
121      * @return this byte vector.
122      */
123     ByteVector put11(final int b1, final int b2) {
124         int length = this.length;
125         if (length + 2 > data.length) {
126             enlarge(2);
127         }
128         byte[] data = this.data;
129         data[length++] = (byte) b1;
130         data[length++] = (byte) b2;
131         this.length = length;
132         return this;
133     }
134 
135     /**
136      * Puts a short into this byte vector. The byte vector is automatically
137      * enlarged if necessary.
138      *
139      * @param s a short.
140      * @return this byte vector.
141      */
142     public ByteVector putShort(final int s) {
143         int length = this.length;
144         if (length + 2 > data.length) {
145             enlarge(2);
146         }
147         byte[] data = this.data;
148         data[length++] = (byte) (s >>> 8);
149         data[length++] = (byte) s;
150         this.length = length;
151         return this;
152     }
153 
154     /**
155      * Puts a byte and a short into this byte vector. The byte vector is
156      * automatically enlarged if necessary.
157      *
158      * @param b a byte.
159      * @param s a short.
160      * @return this byte vector.
161      */
162     ByteVector put12(final int b, final int s) {
163         int length = this.length;
164         if (length + 3 > data.length) {
165             enlarge(3);
166         }
167         byte[] data = this.data;
168         data[length++] = (byte) b;
169         data[length++] = (byte) (s >>> 8);
170         data[length++] = (byte) s;
171         this.length = length;
172         return this;
173     }
174 
175     /**
176      * Puts an int into this byte vector. The byte vector is automatically
177      * enlarged if necessary.
178      *
179      * @param i an int.
180      * @return this byte vector.
181      */
182     public ByteVector putInt(final int i) {
183         int length = this.length;
184         if (length + 4 > data.length) {
185             enlarge(4);
186         }
187         byte[] data = this.data;
188         data[length++] = (byte) (i >>> 24);
189         data[length++] = (byte) (i >>> 16);
190         data[length++] = (byte) (i >>> 8);
191         data[length++] = (byte) i;
192         this.length = length;
193         return this;
194     }
195 
196     /**
197      * Puts a long into this byte vector. The byte vector is automatically
198      * enlarged if necessary.
199      *
200      * @param l a long.
201      * @return this byte vector.
202      */
203     public ByteVector putLong(final long l) {
204         int length = this.length;
205         if (length + 8 > data.length) {
206             enlarge(8);
207         }
208         byte[] data = this.data;
209         int i = (int) (l >>> 32);
210         data[length++] = (byte) (i >>> 24);
211         data[length++] = (byte) (i >>> 16);
212         data[length++] = (byte) (i >>> 8);
213         data[length++] = (byte) i;
214         i = (int) l;
215         data[length++] = (byte) (i >>> 24);
216         data[length++] = (byte) (i >>> 16);
217         data[length++] = (byte) (i >>> 8);
218         data[length++] = (byte) i;
219         this.length = length;
220         return this;
221     }
222 
223     /**
224      * Puts an UTF8 string into this byte vector. The byte vector is
225      * automatically enlarged if necessary.
226      *
227      * @param s a String.
228      * @return this byte vector.
229      */
230     public ByteVector putUTF8(final String s) {
231         int charLength = s.length();
232         if (length + 2 + charLength > data.length) {
233             enlarge(2 + charLength);
234         }
235         int len = length;
236         byte[] data = this.data;
237         // optimistic algorithm: instead of computing the byte length and then
238         // serializing the string (which requires two loops), we assume the byte
239         // length is equal to char length (which is the most frequent case), and
240         // we start serializing the string right away. During the serialization,
241         // if we find that this assumption is wrong, we continue with the
242         // general method.
243         data[len++] = (byte) (charLength >>> 8);
244         data[len++] = (byte) charLength;
245         for (int i = 0; i < charLength; ++i) {
246             char c = s.charAt(i);
247             if (c >= '\001' && c <= '\177') {
248                 data[len++] = (byte) c;
249             } else {
250                 int byteLength = i;
251                 for (int j = i; j < charLength; ++j) {
252                     c = s.charAt(j);
253                     if (c >= '\001' && c <= '\177') {
254                         byteLength++;
255                     } else if (c > '\u07FF') {
256                         byteLength += 3;
257                     } else {
258                         byteLength += 2;
259                     }
260                 }
261                 data[length] = (byte) (byteLength >>> 8);
262                 data[length + 1] = (byte) byteLength;
263                 if (length + 2 + byteLength > data.length) {
264                     length = len;
265                     enlarge(2 + byteLength);
266                     data = this.data;
267                 }
268                 for (int j = i; j < charLength; ++j) {
269                     c = s.charAt(j);
270                     if (c >= '\001' && c <= '\177') {
271                         data[len++] = (byte) c;
272                     } else if (c > '\u07FF') {
273                         data[len++] = (byte) (0xE0 | c >> 12 & 0xF);
274                         data[len++] = (byte) (0x80 | c >> 6 & 0x3F);
275                         data[len++] = (byte) (0x80 | c & 0x3F);
276                     } else {
277                         data[len++] = (byte) (0xC0 | c >> 6 & 0x1F);
278                         data[len++] = (byte) (0x80 | c & 0x3F);
279                     }
280                 }
281                 break;
282             }
283         }
284         length = len;
285         return this;
286     }
287 
288     /**
289      * Puts an array of bytes into this byte vector. The byte vector is
290      * automatically enlarged if necessary.
291      *
292      * @param b an array of bytes. May be <tt>null</tt> to put <tt>len</tt>
293      *        null bytes into this byte vector.
294      * @param off index of the fist byte of b that must be copied.
295      * @param len number of bytes of b that must be copied.
296      * @return this byte vector.
297      */
298     public ByteVector putByteArray(final byte[] b, final int off, final int len)
299     {
300         if (length + len > data.length) {
301             enlarge(len);
302         }
303         if (b != null) {
304             System.arraycopy(b, off, data, length, len);
305         }
306         length += len;
307         return this;
308     }
309 
310     /**
311      * Enlarge this byte vector so that it can receive n more bytes.
312      *
313      * @param size number of additional bytes that this byte vector should be
314      *        able to receive.
315      */
316     private void enlarge(final int size) {
317         int length1 = 2 * data.length;
318         int length2 = length + size;
319         byte[] newData = new byte[length1 > length2 ? length1 : length2];
320         System.arraycopy(data, 0, newData, 0, length);
321         data = newData;
322     }
323 }