1 /* 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 3 * 4 * This code is free software; you can redistribute it and/or modify it 5 * under the terms of the GNU General Public License version 2 only, as 6 * published by the Free Software Foundation. Oracle designates this 7 * particular file as subject to the "Classpath" exception as provided 8 * by Oracle in the LICENSE file that accompanied this code. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 */ 24 25 /* 26 * This file is available under and governed by the GNU General Public 27 * License version 2 only, as published by the Free Software Foundation. 28 * However, the following notice accompanied the original version of this 29 * file: 30 * 31 * ASM: a very small and fast Java bytecode manipulation framework 32 * Copyright (c) 2000-2011 INRIA, France Telecom 33 * All rights reserved. 34 * 35 * Redistribution and use in source and binary forms, with or without 36 * modification, are permitted provided that the following conditions 37 * are met: 38 * 1. Redistributions of source code must retain the above copyright 39 * notice, this list of conditions and the following disclaimer. 40 * 2. Redistributions in binary form must reproduce the above copyright 41 * notice, this list of conditions and the following disclaimer in the 42 * documentation and/or other materials provided with the distribution. 43 * 3. Neither the name of the copyright holders nor the names of its 44 * contributors may be used to endorse or promote products derived from 45 * this software without specific prior written permission. 46 * 47 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 48 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 50 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 51 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 52 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 53 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 54 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 55 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 56 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 57 * THE POSSIBILITY OF SUCH DAMAGE. 58 */ 59 package jdk.internal.org.objectweb.asm; 60 61 /** 62 * A dynamically extensible vector of bytes. This class is roughly equivalent to 63 * a DataOutputStream on top of a ByteArrayOutputStream, but is more efficient. 64 * 65 * @author Eric Bruneton 66 */ 67 public class ByteVector { 68 69 /** 70 * The content of this vector. 71 */ 72 byte[] data; 73 74 /** 75 * Actual number of bytes in this vector. 76 */ 77 int length; 78 79 /** 80 * Constructs a new {@link ByteVector ByteVector} with a default initial 81 * size. 82 */ ByteVector()83 public ByteVector() { 84 data = new byte[64]; 85 } 86 87 /** 88 * Constructs a new {@link ByteVector ByteVector} with the given initial 89 * size. 90 * 91 * @param initialSize 92 * the initial size of the byte vector to be constructed. 93 */ ByteVector(final int initialSize)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 103 * a byte. 104 * @return this byte vector. 105 */ putByte(final int b)106 public ByteVector putByte(final int b) { 107 int length = this.length; 108 if (length + 1 > data.length) { 109 enlarge(1); 110 } 111 data[length++] = (byte) b; 112 this.length = length; 113 return this; 114 } 115 116 /** 117 * Puts two bytes into this byte vector. The byte vector is automatically 118 * enlarged if necessary. 119 * 120 * @param b1 121 * a byte. 122 * @param b2 123 * another byte. 124 * @return this byte vector. 125 */ put11(final int b1, final int b2)126 ByteVector put11(final int b1, final int b2) { 127 int length = this.length; 128 if (length + 2 > data.length) { 129 enlarge(2); 130 } 131 byte[] data = this.data; 132 data[length++] = (byte) b1; 133 data[length++] = (byte) b2; 134 this.length = length; 135 return this; 136 } 137 138 /** 139 * Puts a short into this byte vector. The byte vector is automatically 140 * enlarged if necessary. 141 * 142 * @param s 143 * a short. 144 * @return this byte vector. 145 */ putShort(final int s)146 public ByteVector putShort(final int s) { 147 int length = this.length; 148 if (length + 2 > data.length) { 149 enlarge(2); 150 } 151 byte[] data = this.data; 152 data[length++] = (byte) (s >>> 8); 153 data[length++] = (byte) s; 154 this.length = length; 155 return this; 156 } 157 158 /** 159 * Puts a byte and a short into this byte vector. The byte vector is 160 * automatically enlarged if necessary. 161 * 162 * @param b 163 * a byte. 164 * @param s 165 * a short. 166 * @return this byte vector. 167 */ put12(final int b, final int s)168 ByteVector put12(final int b, final int s) { 169 int length = this.length; 170 if (length + 3 > data.length) { 171 enlarge(3); 172 } 173 byte[] data = this.data; 174 data[length++] = (byte) b; 175 data[length++] = (byte) (s >>> 8); 176 data[length++] = (byte) s; 177 this.length = length; 178 return this; 179 } 180 181 /** 182 * Puts an int into this byte vector. The byte vector is automatically 183 * enlarged if necessary. 184 * 185 * @param i 186 * an int. 187 * @return this byte vector. 188 */ putInt(final int i)189 public ByteVector putInt(final int i) { 190 int length = this.length; 191 if (length + 4 > data.length) { 192 enlarge(4); 193 } 194 byte[] data = this.data; 195 data[length++] = (byte) (i >>> 24); 196 data[length++] = (byte) (i >>> 16); 197 data[length++] = (byte) (i >>> 8); 198 data[length++] = (byte) i; 199 this.length = length; 200 return this; 201 } 202 203 /** 204 * Puts a long into this byte vector. The byte vector is automatically 205 * enlarged if necessary. 206 * 207 * @param l 208 * a long. 209 * @return this byte vector. 210 */ putLong(final long l)211 public ByteVector putLong(final long l) { 212 int length = this.length; 213 if (length + 8 > data.length) { 214 enlarge(8); 215 } 216 byte[] data = this.data; 217 int i = (int) (l >>> 32); 218 data[length++] = (byte) (i >>> 24); 219 data[length++] = (byte) (i >>> 16); 220 data[length++] = (byte) (i >>> 8); 221 data[length++] = (byte) i; 222 i = (int) l; 223 data[length++] = (byte) (i >>> 24); 224 data[length++] = (byte) (i >>> 16); 225 data[length++] = (byte) (i >>> 8); 226 data[length++] = (byte) i; 227 this.length = length; 228 return this; 229 } 230 231 /** 232 * Puts an UTF8 string into this byte vector. The byte vector is 233 * automatically enlarged if necessary. 234 * 235 * @param s 236 * a String whose UTF8 encoded length must be less than 65536. 237 * @return this byte vector. 238 */ putUTF8(final String s)239 public ByteVector putUTF8(final String s) { 240 int charLength = s.length(); 241 if (charLength > 65535) { 242 throw new IllegalArgumentException(); 243 } 244 int len = length; 245 if (len + 2 + charLength > data.length) { 246 enlarge(2 + charLength); 247 } 248 byte[] data = this.data; 249 // optimistic algorithm: instead of computing the byte length and then 250 // serializing the string (which requires two loops), we assume the byte 251 // length is equal to char length (which is the most frequent case), and 252 // we start serializing the string right away. During the serialization, 253 // if we find that this assumption is wrong, we continue with the 254 // general method. 255 data[len++] = (byte) (charLength >>> 8); 256 data[len++] = (byte) charLength; 257 for (int i = 0; i < charLength; ++i) { 258 char c = s.charAt(i); 259 if (c >= '\001' && c <= '\177') { 260 data[len++] = (byte) c; 261 } else { 262 length = len; 263 return encodeUTF8(s, i, 65535); 264 } 265 } 266 length = len; 267 return this; 268 } 269 270 /** 271 * Puts an UTF8 string into this byte vector. The byte vector is 272 * automatically enlarged if necessary. The string length is encoded in two 273 * bytes before the encoded characters, if there is space for that (i.e. if 274 * this.length - i - 2 >= 0). 275 * 276 * @param s 277 * the String to encode. 278 * @param i 279 * the index of the first character to encode. The previous 280 * characters are supposed to have already been encoded, using 281 * only one byte per character. 282 * @param maxByteLength 283 * the maximum byte length of the encoded string, including the 284 * already encoded characters. 285 * @return this byte vector. 286 */ encodeUTF8(final String s, int i, int maxByteLength)287 ByteVector encodeUTF8(final String s, int i, int maxByteLength) { 288 int charLength = s.length(); 289 int byteLength = i; 290 char c; 291 for (int j = i; j < charLength; ++j) { 292 c = s.charAt(j); 293 if (c >= '\001' && c <= '\177') { 294 byteLength++; 295 } else if (c > '\u07FF') { 296 byteLength += 3; 297 } else { 298 byteLength += 2; 299 } 300 } 301 if (byteLength > maxByteLength) { 302 throw new IllegalArgumentException(); 303 } 304 int start = length - i - 2; 305 if (start >= 0) { 306 data[start] = (byte) (byteLength >>> 8); 307 data[start + 1] = (byte) byteLength; 308 } 309 if (length + byteLength - i > data.length) { 310 enlarge(byteLength - i); 311 } 312 int len = length; 313 for (int j = i; j < charLength; ++j) { 314 c = s.charAt(j); 315 if (c >= '\001' && c <= '\177') { 316 data[len++] = (byte) c; 317 } else if (c > '\u07FF') { 318 data[len++] = (byte) (0xE0 | c >> 12 & 0xF); 319 data[len++] = (byte) (0x80 | c >> 6 & 0x3F); 320 data[len++] = (byte) (0x80 | c & 0x3F); 321 } else { 322 data[len++] = (byte) (0xC0 | c >> 6 & 0x1F); 323 data[len++] = (byte) (0x80 | c & 0x3F); 324 } 325 } 326 length = len; 327 return this; 328 } 329 330 /** 331 * Puts an array of bytes into this byte vector. The byte vector is 332 * automatically enlarged if necessary. 333 * 334 * @param b 335 * an array of bytes. May be <tt>null</tt> to put <tt>len</tt> 336 * null bytes into this byte vector. 337 * @param off 338 * index of the fist byte of b that must be copied. 339 * @param len 340 * number of bytes of b that must be copied. 341 * @return this byte vector. 342 */ putByteArray(final byte[] b, final int off, final int len)343 public ByteVector putByteArray(final byte[] b, final int off, final int len) { 344 if (length + len > data.length) { 345 enlarge(len); 346 } 347 if (b != null) { 348 System.arraycopy(b, off, data, length, len); 349 } 350 length += len; 351 return this; 352 } 353 354 /** 355 * Enlarge this byte vector so that it can receive n more bytes. 356 * 357 * @param size 358 * number of additional bytes that this byte vector should be 359 * able to receive. 360 */ enlarge(final int size)361 private void enlarge(final int size) { 362 int length1 = 2 * data.length; 363 int length2 = length + size; 364 byte[] newData = new byte[length1 > length2 ? length1 : length2]; 365 System.arraycopy(data, 0, newData, 0, length); 366 data = newData; 367 } 368 } 369