J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2007 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package javax.imageio.stream; |
| 27 | |
| 28 | import java.io.DataInputStream; |
| 29 | import java.io.EOFException; |
| 30 | import java.io.IOException; |
| 31 | import java.nio.ByteOrder; |
| 32 | import java.util.Stack; |
| 33 | import javax.imageio.IIOException; |
| 34 | |
| 35 | /** |
| 36 | * An abstract class implementing the <code>ImageInputStream</code> interface. |
| 37 | * This class is designed to reduce the number of methods that must |
| 38 | * be implemented by subclasses. |
| 39 | * |
| 40 | * <p> In particular, this class handles most or all of the details of |
| 41 | * byte order interpretation, buffering, mark/reset, discarding, |
| 42 | * closing, and disposing. |
| 43 | */ |
| 44 | public abstract class ImageInputStreamImpl implements ImageInputStream { |
| 45 | |
| 46 | private Stack markByteStack = new Stack(); |
| 47 | |
| 48 | private Stack markBitStack = new Stack(); |
| 49 | |
| 50 | private boolean isClosed = false; |
| 51 | |
| 52 | // Length of the buffer used for readFully(type[], int, int) |
| 53 | private static final int BYTE_BUF_LENGTH = 8192; |
| 54 | |
| 55 | /** |
| 56 | * Byte buffer used for readFully(type[], int, int). Note that this |
| 57 | * array is also used for bulk reads in readShort(), readInt(), etc, so |
| 58 | * it should be large enough to hold a primitive value (i.e. >= 8 bytes). |
| 59 | * Also note that this array is package protected, so that it can be |
| 60 | * used by ImageOutputStreamImpl in a similar manner. |
| 61 | */ |
| 62 | byte[] byteBuf = new byte[BYTE_BUF_LENGTH]; |
| 63 | |
| 64 | /** |
| 65 | * The byte order of the stream as an instance of the enumeration |
| 66 | * class <code>java.nio.ByteOrder</code>, where |
| 67 | * <code>ByteOrder.BIG_ENDIAN</code> indicates network byte order |
| 68 | * and <code>ByteOrder.LITTLE_ENDIAN</code> indicates the reverse |
| 69 | * order. By default, the value is |
| 70 | * <code>ByteOrder.BIG_ENDIAN</code>. |
| 71 | */ |
| 72 | protected ByteOrder byteOrder = ByteOrder.BIG_ENDIAN; |
| 73 | |
| 74 | /** |
| 75 | * The current read position within the stream. Subclasses are |
| 76 | * responsible for keeping this value current from any method they |
| 77 | * override that alters the read position. |
| 78 | */ |
| 79 | protected long streamPos; |
| 80 | |
| 81 | /** |
| 82 | * The current bit offset within the stream. Subclasses are |
| 83 | * responsible for keeping this value current from any method they |
| 84 | * override that alters the bit offset. |
| 85 | */ |
| 86 | protected int bitOffset; |
| 87 | |
| 88 | /** |
| 89 | * The position prior to which data may be discarded. Seeking |
| 90 | * to a smaller position is not allowed. <code>flushedPos</code> |
| 91 | * will always be >= 0. |
| 92 | */ |
| 93 | protected long flushedPos = 0; |
| 94 | |
| 95 | /** |
| 96 | * Constructs an <code>ImageInputStreamImpl</code>. |
| 97 | */ |
| 98 | public ImageInputStreamImpl() { |
| 99 | } |
| 100 | |
| 101 | /** |
| 102 | * Throws an <code>IOException</code> if the stream has been closed. |
| 103 | * Subclasses may call this method from any of their methods that |
| 104 | * require the stream not to be closed. |
| 105 | * |
| 106 | * @exception IOException if the stream is closed. |
| 107 | */ |
| 108 | protected final void checkClosed() throws IOException { |
| 109 | if (isClosed) { |
| 110 | throw new IOException("closed"); |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | public void setByteOrder(ByteOrder byteOrder) { |
| 115 | this.byteOrder = byteOrder; |
| 116 | } |
| 117 | |
| 118 | public ByteOrder getByteOrder() { |
| 119 | return byteOrder; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * Reads a single byte from the stream and returns it as an |
| 124 | * <code>int</code> between 0 and 255. If EOF is reached, |
| 125 | * <code>-1</code> is returned. |
| 126 | * |
| 127 | * <p> Subclasses must provide an implementation for this method. |
| 128 | * The subclass implementation should update the stream position |
| 129 | * before exiting. |
| 130 | * |
| 131 | * <p> The bit offset within the stream must be reset to zero before |
| 132 | * the read occurs. |
| 133 | * |
| 134 | * @return the value of the next byte in the stream, or <code>-1</code> |
| 135 | * if EOF is reached. |
| 136 | * |
| 137 | * @exception IOException if the stream has been closed. |
| 138 | */ |
| 139 | public abstract int read() throws IOException; |
| 140 | |
| 141 | /** |
| 142 | * A convenience method that calls <code>read(b, 0, b.length)</code>. |
| 143 | * |
| 144 | * <p> The bit offset within the stream is reset to zero before |
| 145 | * the read occurs. |
| 146 | * |
| 147 | * @return the number of bytes actually read, or <code>-1</code> |
| 148 | * to indicate EOF. |
| 149 | * |
| 150 | * @exception NullPointerException if <code>b</code> is |
| 151 | * <code>null</code>. |
| 152 | * @exception IOException if an I/O error occurs. |
| 153 | */ |
| 154 | public int read(byte[] b) throws IOException { |
| 155 | return read(b, 0, b.length); |
| 156 | } |
| 157 | |
| 158 | /** |
| 159 | * Reads up to <code>len</code> bytes from the stream, and stores |
| 160 | * them into <code>b</code> starting at index <code>off</code>. |
| 161 | * If no bytes can be read because the end of the stream has been |
| 162 | * reached, <code>-1</code> is returned. |
| 163 | * |
| 164 | * <p> The bit offset within the stream must be reset to zero before |
| 165 | * the read occurs. |
| 166 | * |
| 167 | * <p> Subclasses must provide an implementation for this method. |
| 168 | * The subclass implementation should update the stream position |
| 169 | * before exiting. |
| 170 | * |
| 171 | * @param b an array of bytes to be written to. |
| 172 | * @param off the starting position within <code>b</code> to write to. |
| 173 | * @param len the maximum number of bytes to read. |
| 174 | * |
| 175 | * @return the number of bytes actually read, or <code>-1</code> |
| 176 | * to indicate EOF. |
| 177 | * |
| 178 | * @exception IndexOutOfBoundsException if <code>off</code> is |
| 179 | * negative, <code>len</code> is negative, or <code>off + |
| 180 | * len</code> is greater than <code>b.length</code>. |
| 181 | * @exception NullPointerException if <code>b</code> is |
| 182 | * <code>null</code>. |
| 183 | * @exception IOException if an I/O error occurs. |
| 184 | */ |
| 185 | public abstract int read(byte[] b, int off, int len) throws IOException; |
| 186 | |
| 187 | public void readBytes(IIOByteBuffer buf, int len) throws IOException { |
| 188 | if (len < 0) { |
| 189 | throw new IndexOutOfBoundsException("len < 0!"); |
| 190 | } |
| 191 | if (buf == null) { |
| 192 | throw new NullPointerException("buf == null!"); |
| 193 | } |
| 194 | |
| 195 | byte[] data = new byte[len]; |
| 196 | len = read(data, 0, len); |
| 197 | |
| 198 | buf.setData(data); |
| 199 | buf.setOffset(0); |
| 200 | buf.setLength(len); |
| 201 | } |
| 202 | |
| 203 | public boolean readBoolean() throws IOException { |
| 204 | int ch = this.read(); |
| 205 | if (ch < 0) { |
| 206 | throw new EOFException(); |
| 207 | } |
| 208 | return (ch != 0); |
| 209 | } |
| 210 | |
| 211 | public byte readByte() throws IOException { |
| 212 | int ch = this.read(); |
| 213 | if (ch < 0) { |
| 214 | throw new EOFException(); |
| 215 | } |
| 216 | return (byte)ch; |
| 217 | } |
| 218 | |
| 219 | public int readUnsignedByte() throws IOException { |
| 220 | int ch = this.read(); |
| 221 | if (ch < 0) { |
| 222 | throw new EOFException(); |
| 223 | } |
| 224 | return ch; |
| 225 | } |
| 226 | |
| 227 | public short readShort() throws IOException { |
| 228 | if (read(byteBuf, 0, 2) < 0) { |
| 229 | throw new EOFException(); |
| 230 | } |
| 231 | |
| 232 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 233 | return (short) |
| 234 | (((byteBuf[0] & 0xff) << 8) | ((byteBuf[1] & 0xff) << 0)); |
| 235 | } else { |
| 236 | return (short) |
| 237 | (((byteBuf[1] & 0xff) << 8) | ((byteBuf[0] & 0xff) << 0)); |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | public int readUnsignedShort() throws IOException { |
| 242 | return ((int)readShort()) & 0xffff; |
| 243 | } |
| 244 | |
| 245 | public char readChar() throws IOException { |
| 246 | return (char)readShort(); |
| 247 | } |
| 248 | |
| 249 | public int readInt() throws IOException { |
| 250 | if (read(byteBuf, 0, 4) < 0) { |
| 251 | throw new EOFException(); |
| 252 | } |
| 253 | |
| 254 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 255 | return |
| 256 | (((byteBuf[0] & 0xff) << 24) | ((byteBuf[1] & 0xff) << 16) | |
| 257 | ((byteBuf[2] & 0xff) << 8) | ((byteBuf[3] & 0xff) << 0)); |
| 258 | } else { |
| 259 | return |
| 260 | (((byteBuf[3] & 0xff) << 24) | ((byteBuf[2] & 0xff) << 16) | |
| 261 | ((byteBuf[1] & 0xff) << 8) | ((byteBuf[0] & 0xff) << 0)); |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | public long readUnsignedInt() throws IOException { |
| 266 | return ((long)readInt()) & 0xffffffffL; |
| 267 | } |
| 268 | |
| 269 | public long readLong() throws IOException { |
| 270 | // REMIND: Once 6277756 is fixed, we should do a bulk read of all 8 |
| 271 | // bytes here as we do in readShort() and readInt() for even better |
| 272 | // performance (see 6347575 for details). |
| 273 | int i1 = readInt(); |
| 274 | int i2 = readInt(); |
| 275 | |
| 276 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 277 | return ((long)i1 << 32) + (i2 & 0xFFFFFFFFL); |
| 278 | } else { |
| 279 | return ((long)i2 << 32) + (i1 & 0xFFFFFFFFL); |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | public float readFloat() throws IOException { |
| 284 | return Float.intBitsToFloat(readInt()); |
| 285 | } |
| 286 | |
| 287 | public double readDouble() throws IOException { |
| 288 | return Double.longBitsToDouble(readLong()); |
| 289 | } |
| 290 | |
| 291 | public String readLine() throws IOException { |
| 292 | StringBuffer input = new StringBuffer(); |
| 293 | int c = -1; |
| 294 | boolean eol = false; |
| 295 | |
| 296 | while (!eol) { |
| 297 | switch (c = read()) { |
| 298 | case -1: |
| 299 | case '\n': |
| 300 | eol = true; |
| 301 | break; |
| 302 | case '\r': |
| 303 | eol = true; |
| 304 | long cur = getStreamPosition(); |
| 305 | if ((read()) != '\n') { |
| 306 | seek(cur); |
| 307 | } |
| 308 | break; |
| 309 | default: |
| 310 | input.append((char)c); |
| 311 | break; |
| 312 | } |
| 313 | } |
| 314 | |
| 315 | if ((c == -1) && (input.length() == 0)) { |
| 316 | return null; |
| 317 | } |
| 318 | return input.toString(); |
| 319 | } |
| 320 | |
| 321 | public String readUTF() throws IOException { |
| 322 | this.bitOffset = 0; |
| 323 | |
| 324 | // Fix 4494369: method ImageInputStreamImpl.readUTF() |
| 325 | // does not work as specified (it should always assume |
| 326 | // network byte order). |
| 327 | ByteOrder oldByteOrder = getByteOrder(); |
| 328 | setByteOrder(ByteOrder.BIG_ENDIAN); |
| 329 | |
| 330 | String ret; |
| 331 | try { |
| 332 | ret = DataInputStream.readUTF(this); |
| 333 | } catch (IOException e) { |
| 334 | // Restore the old byte order even if an exception occurs |
| 335 | setByteOrder(oldByteOrder); |
| 336 | throw e; |
| 337 | } |
| 338 | |
| 339 | setByteOrder(oldByteOrder); |
| 340 | return ret; |
| 341 | } |
| 342 | |
| 343 | public void readFully(byte[] b, int off, int len) throws IOException { |
| 344 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 345 | if (off < 0 || len < 0 || off + len > b.length || off + len < 0) { |
| 346 | throw new IndexOutOfBoundsException |
| 347 | ("off < 0 || len < 0 || off + len > b.length!"); |
| 348 | } |
| 349 | |
| 350 | while (len > 0) { |
| 351 | int nbytes = read(b, off, len); |
| 352 | if (nbytes == -1) { |
| 353 | throw new EOFException(); |
| 354 | } |
| 355 | off += nbytes; |
| 356 | len -= nbytes; |
| 357 | } |
| 358 | } |
| 359 | |
| 360 | public void readFully(byte[] b) throws IOException { |
| 361 | readFully(b, 0, b.length); |
| 362 | } |
| 363 | |
| 364 | public void readFully(short[] s, int off, int len) throws IOException { |
| 365 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 366 | if (off < 0 || len < 0 || off + len > s.length || off + len < 0) { |
| 367 | throw new IndexOutOfBoundsException |
| 368 | ("off < 0 || len < 0 || off + len > s.length!"); |
| 369 | } |
| 370 | |
| 371 | while (len > 0) { |
| 372 | int nelts = Math.min(len, byteBuf.length/2); |
| 373 | readFully(byteBuf, 0, nelts*2); |
| 374 | toShorts(byteBuf, s, off, nelts); |
| 375 | off += nelts; |
| 376 | len -= nelts; |
| 377 | } |
| 378 | } |
| 379 | |
| 380 | public void readFully(char[] c, int off, int len) throws IOException { |
| 381 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 382 | if (off < 0 || len < 0 || off + len > c.length || off + len < 0) { |
| 383 | throw new IndexOutOfBoundsException |
| 384 | ("off < 0 || len < 0 || off + len > c.length!"); |
| 385 | } |
| 386 | |
| 387 | while (len > 0) { |
| 388 | int nelts = Math.min(len, byteBuf.length/2); |
| 389 | readFully(byteBuf, 0, nelts*2); |
| 390 | toChars(byteBuf, c, off, nelts); |
| 391 | off += nelts; |
| 392 | len -= nelts; |
| 393 | } |
| 394 | } |
| 395 | |
| 396 | public void readFully(int[] i, int off, int len) throws IOException { |
| 397 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 398 | if (off < 0 || len < 0 || off + len > i.length || off + len < 0) { |
| 399 | throw new IndexOutOfBoundsException |
| 400 | ("off < 0 || len < 0 || off + len > i.length!"); |
| 401 | } |
| 402 | |
| 403 | while (len > 0) { |
| 404 | int nelts = Math.min(len, byteBuf.length/4); |
| 405 | readFully(byteBuf, 0, nelts*4); |
| 406 | toInts(byteBuf, i, off, nelts); |
| 407 | off += nelts; |
| 408 | len -= nelts; |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | public void readFully(long[] l, int off, int len) throws IOException { |
| 413 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 414 | if (off < 0 || len < 0 || off + len > l.length || off + len < 0) { |
| 415 | throw new IndexOutOfBoundsException |
| 416 | ("off < 0 || len < 0 || off + len > l.length!"); |
| 417 | } |
| 418 | |
| 419 | while (len > 0) { |
| 420 | int nelts = Math.min(len, byteBuf.length/8); |
| 421 | readFully(byteBuf, 0, nelts*8); |
| 422 | toLongs(byteBuf, l, off, nelts); |
| 423 | off += nelts; |
| 424 | len -= nelts; |
| 425 | } |
| 426 | } |
| 427 | |
| 428 | public void readFully(float[] f, int off, int len) throws IOException { |
| 429 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 430 | if (off < 0 || len < 0 || off + len > f.length || off + len < 0) { |
| 431 | throw new IndexOutOfBoundsException |
| 432 | ("off < 0 || len < 0 || off + len > f.length!"); |
| 433 | } |
| 434 | |
| 435 | while (len > 0) { |
| 436 | int nelts = Math.min(len, byteBuf.length/4); |
| 437 | readFully(byteBuf, 0, nelts*4); |
| 438 | toFloats(byteBuf, f, off, nelts); |
| 439 | off += nelts; |
| 440 | len -= nelts; |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | public void readFully(double[] d, int off, int len) throws IOException { |
| 445 | // Fix 4430357 - if off + len < 0, overflow occurred |
| 446 | if (off < 0 || len < 0 || off + len > d.length || off + len < 0) { |
| 447 | throw new IndexOutOfBoundsException |
| 448 | ("off < 0 || len < 0 || off + len > d.length!"); |
| 449 | } |
| 450 | |
| 451 | while (len > 0) { |
| 452 | int nelts = Math.min(len, byteBuf.length/8); |
| 453 | readFully(byteBuf, 0, nelts*8); |
| 454 | toDoubles(byteBuf, d, off, nelts); |
| 455 | off += nelts; |
| 456 | len -= nelts; |
| 457 | } |
| 458 | } |
| 459 | |
| 460 | private void toShorts(byte[] b, short[] s, int off, int len) { |
| 461 | int boff = 0; |
| 462 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 463 | for (int j = 0; j < len; j++) { |
| 464 | int b0 = b[boff]; |
| 465 | int b1 = b[boff + 1] & 0xff; |
| 466 | s[off + j] = (short)((b0 << 8) | b1); |
| 467 | boff += 2; |
| 468 | } |
| 469 | } else { |
| 470 | for (int j = 0; j < len; j++) { |
| 471 | int b0 = b[boff + 1]; |
| 472 | int b1 = b[boff] & 0xff; |
| 473 | s[off + j] = (short)((b0 << 8) | b1); |
| 474 | boff += 2; |
| 475 | } |
| 476 | } |
| 477 | } |
| 478 | |
| 479 | private void toChars(byte[] b, char[] c, int off, int len) { |
| 480 | int boff = 0; |
| 481 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 482 | for (int j = 0; j < len; j++) { |
| 483 | int b0 = b[boff]; |
| 484 | int b1 = b[boff + 1] & 0xff; |
| 485 | c[off + j] = (char)((b0 << 8) | b1); |
| 486 | boff += 2; |
| 487 | } |
| 488 | } else { |
| 489 | for (int j = 0; j < len; j++) { |
| 490 | int b0 = b[boff + 1]; |
| 491 | int b1 = b[boff] & 0xff; |
| 492 | c[off + j] = (char)((b0 << 8) | b1); |
| 493 | boff += 2; |
| 494 | } |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | private void toInts(byte[] b, int[] i, int off, int len) { |
| 499 | int boff = 0; |
| 500 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 501 | for (int j = 0; j < len; j++) { |
| 502 | int b0 = b[boff]; |
| 503 | int b1 = b[boff + 1] & 0xff; |
| 504 | int b2 = b[boff + 2] & 0xff; |
| 505 | int b3 = b[boff + 3] & 0xff; |
| 506 | i[off + j] = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 507 | boff += 4; |
| 508 | } |
| 509 | } else { |
| 510 | for (int j = 0; j < len; j++) { |
| 511 | int b0 = b[boff + 3]; |
| 512 | int b1 = b[boff + 2] & 0xff; |
| 513 | int b2 = b[boff + 1] & 0xff; |
| 514 | int b3 = b[boff] & 0xff; |
| 515 | i[off + j] = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 516 | boff += 4; |
| 517 | } |
| 518 | } |
| 519 | } |
| 520 | |
| 521 | private void toLongs(byte[] b, long[] l, int off, int len) { |
| 522 | int boff = 0; |
| 523 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 524 | for (int j = 0; j < len; j++) { |
| 525 | int b0 = b[boff]; |
| 526 | int b1 = b[boff + 1] & 0xff; |
| 527 | int b2 = b[boff + 2] & 0xff; |
| 528 | int b3 = b[boff + 3] & 0xff; |
| 529 | int b4 = b[boff + 4]; |
| 530 | int b5 = b[boff + 5] & 0xff; |
| 531 | int b6 = b[boff + 6] & 0xff; |
| 532 | int b7 = b[boff + 7] & 0xff; |
| 533 | |
| 534 | int i0 = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 535 | int i1 = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7; |
| 536 | |
| 537 | l[off + j] = ((long)i0 << 32) | (i1 & 0xffffffffL); |
| 538 | boff += 8; |
| 539 | } |
| 540 | } else { |
| 541 | for (int j = 0; j < len; j++) { |
| 542 | int b0 = b[boff + 7]; |
| 543 | int b1 = b[boff + 6] & 0xff; |
| 544 | int b2 = b[boff + 5] & 0xff; |
| 545 | int b3 = b[boff + 4] & 0xff; |
| 546 | int b4 = b[boff + 3]; |
| 547 | int b5 = b[boff + 2] & 0xff; |
| 548 | int b6 = b[boff + 1] & 0xff; |
| 549 | int b7 = b[boff] & 0xff; |
| 550 | |
| 551 | int i0 = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 552 | int i1 = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7; |
| 553 | |
| 554 | l[off + j] = ((long)i0 << 32) | (i1 & 0xffffffffL); |
| 555 | boff += 8; |
| 556 | } |
| 557 | } |
| 558 | } |
| 559 | |
| 560 | private void toFloats(byte[] b, float[] f, int off, int len) { |
| 561 | int boff = 0; |
| 562 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 563 | for (int j = 0; j < len; j++) { |
| 564 | int b0 = b[boff]; |
| 565 | int b1 = b[boff + 1] & 0xff; |
| 566 | int b2 = b[boff + 2] & 0xff; |
| 567 | int b3 = b[boff + 3] & 0xff; |
| 568 | int i = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 569 | f[off + j] = Float.intBitsToFloat(i); |
| 570 | boff += 4; |
| 571 | } |
| 572 | } else { |
| 573 | for (int j = 0; j < len; j++) { |
| 574 | int b0 = b[boff + 3]; |
| 575 | int b1 = b[boff + 2] & 0xff; |
| 576 | int b2 = b[boff + 1] & 0xff; |
| 577 | int b3 = b[boff + 0] & 0xff; |
| 578 | int i = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 579 | f[off + j] = Float.intBitsToFloat(i); |
| 580 | boff += 4; |
| 581 | } |
| 582 | } |
| 583 | } |
| 584 | |
| 585 | private void toDoubles(byte[] b, double[] d, int off, int len) { |
| 586 | int boff = 0; |
| 587 | if (byteOrder == ByteOrder.BIG_ENDIAN) { |
| 588 | for (int j = 0; j < len; j++) { |
| 589 | int b0 = b[boff]; |
| 590 | int b1 = b[boff + 1] & 0xff; |
| 591 | int b2 = b[boff + 2] & 0xff; |
| 592 | int b3 = b[boff + 3] & 0xff; |
| 593 | int b4 = b[boff + 4]; |
| 594 | int b5 = b[boff + 5] & 0xff; |
| 595 | int b6 = b[boff + 6] & 0xff; |
| 596 | int b7 = b[boff + 7] & 0xff; |
| 597 | |
| 598 | int i0 = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 599 | int i1 = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7; |
| 600 | long l = ((long)i0 << 32) | (i1 & 0xffffffffL); |
| 601 | |
| 602 | d[off + j] = Double.longBitsToDouble(l); |
| 603 | boff += 8; |
| 604 | } |
| 605 | } else { |
| 606 | for (int j = 0; j < len; j++) { |
| 607 | int b0 = b[boff + 7]; |
| 608 | int b1 = b[boff + 6] & 0xff; |
| 609 | int b2 = b[boff + 5] & 0xff; |
| 610 | int b3 = b[boff + 4] & 0xff; |
| 611 | int b4 = b[boff + 3]; |
| 612 | int b5 = b[boff + 2] & 0xff; |
| 613 | int b6 = b[boff + 1] & 0xff; |
| 614 | int b7 = b[boff] & 0xff; |
| 615 | |
| 616 | int i0 = (b0 << 24) | (b1 << 16) | (b2 << 8) | b3; |
| 617 | int i1 = (b4 << 24) | (b5 << 16) | (b6 << 8) | b7; |
| 618 | long l = ((long)i0 << 32) | (i1 & 0xffffffffL); |
| 619 | |
| 620 | d[off + j] = Double.longBitsToDouble(l); |
| 621 | boff += 8; |
| 622 | } |
| 623 | } |
| 624 | } |
| 625 | |
| 626 | public long getStreamPosition() throws IOException { |
| 627 | checkClosed(); |
| 628 | return streamPos; |
| 629 | } |
| 630 | |
| 631 | public int getBitOffset() throws IOException { |
| 632 | checkClosed(); |
| 633 | return bitOffset; |
| 634 | } |
| 635 | |
| 636 | public void setBitOffset(int bitOffset) throws IOException { |
| 637 | checkClosed(); |
| 638 | if (bitOffset < 0 || bitOffset > 7) { |
| 639 | throw new IllegalArgumentException("bitOffset must be betwwen 0 and 7!"); |
| 640 | } |
| 641 | this.bitOffset = bitOffset; |
| 642 | } |
| 643 | |
| 644 | public int readBit() throws IOException { |
| 645 | checkClosed(); |
| 646 | |
| 647 | // Compute final bit offset before we call read() and seek() |
| 648 | int newBitOffset = (this.bitOffset + 1) & 0x7; |
| 649 | |
| 650 | int val = read(); |
| 651 | if (val == -1) { |
| 652 | throw new EOFException(); |
| 653 | } |
| 654 | |
| 655 | if (newBitOffset != 0) { |
| 656 | // Move byte position back if in the middle of a byte |
| 657 | seek(getStreamPosition() - 1); |
| 658 | // Shift the bit to be read to the rightmost position |
| 659 | val >>= 8 - newBitOffset; |
| 660 | } |
| 661 | this.bitOffset = newBitOffset; |
| 662 | |
| 663 | return val & 0x1; |
| 664 | } |
| 665 | |
| 666 | public long readBits(int numBits) throws IOException { |
| 667 | checkClosed(); |
| 668 | |
| 669 | if (numBits < 0 || numBits > 64) { |
| 670 | throw new IllegalArgumentException(); |
| 671 | } |
| 672 | if (numBits == 0) { |
| 673 | return 0L; |
| 674 | } |
| 675 | |
| 676 | // Have to read additional bits on the left equal to the bit offset |
| 677 | int bitsToRead = numBits + bitOffset; |
| 678 | |
| 679 | // Compute final bit offset before we call read() and seek() |
| 680 | int newBitOffset = (this.bitOffset + numBits) & 0x7; |
| 681 | |
| 682 | // Read a byte at a time, accumulate |
| 683 | long accum = 0L; |
| 684 | while (bitsToRead > 0) { |
| 685 | int val = read(); |
| 686 | if (val == -1) { |
| 687 | throw new EOFException(); |
| 688 | } |
| 689 | |
| 690 | accum <<= 8; |
| 691 | accum |= val; |
| 692 | bitsToRead -= 8; |
| 693 | } |
| 694 | |
| 695 | // Move byte position back if in the middle of a byte |
| 696 | if (newBitOffset != 0) { |
| 697 | seek(getStreamPosition() - 1); |
| 698 | } |
| 699 | this.bitOffset = newBitOffset; |
| 700 | |
| 701 | // Shift away unwanted bits on the right. |
| 702 | accum >>>= (-bitsToRead); // Negative of bitsToRead == extra bits read |
| 703 | |
| 704 | // Mask out unwanted bits on the left |
| 705 | accum &= (-1L >>> (64 - numBits)); |
| 706 | |
| 707 | return accum; |
| 708 | } |
| 709 | |
| 710 | /** |
| 711 | * Returns <code>-1L</code> to indicate that the stream has unknown |
| 712 | * length. Subclasses must override this method to provide actual |
| 713 | * length information. |
| 714 | * |
| 715 | * @return -1L to indicate unknown length. |
| 716 | */ |
| 717 | public long length() { |
| 718 | return -1L; |
| 719 | } |
| 720 | |
| 721 | /** |
| 722 | * Advances the current stream position by calling |
| 723 | * <code>seek(getStreamPosition() + n)</code>. |
| 724 | * |
| 725 | * <p> The bit offset is reset to zero. |
| 726 | * |
| 727 | * @param n the number of bytes to seek forward. |
| 728 | * |
| 729 | * @return an <code>int</code> representing the number of bytes |
| 730 | * skipped. |
| 731 | * |
| 732 | * @exception IOException if <code>getStreamPosition</code> |
| 733 | * throws an <code>IOException</code> when computing either |
| 734 | * the starting or ending position. |
| 735 | */ |
| 736 | public int skipBytes(int n) throws IOException { |
| 737 | long pos = getStreamPosition(); |
| 738 | seek(pos + n); |
| 739 | return (int)(getStreamPosition() - pos); |
| 740 | } |
| 741 | |
| 742 | /** |
| 743 | * Advances the current stream position by calling |
| 744 | * <code>seek(getStreamPosition() + n)</code>. |
| 745 | * |
| 746 | * <p> The bit offset is reset to zero. |
| 747 | * |
| 748 | * @param n the number of bytes to seek forward. |
| 749 | * |
| 750 | * @return a <code>long</code> representing the number of bytes |
| 751 | * skipped. |
| 752 | * |
| 753 | * @exception IOException if <code>getStreamPosition</code> |
| 754 | * throws an <code>IOException</code> when computing either |
| 755 | * the starting or ending position. |
| 756 | */ |
| 757 | public long skipBytes(long n) throws IOException { |
| 758 | long pos = getStreamPosition(); |
| 759 | seek(pos + n); |
| 760 | return getStreamPosition() - pos; |
| 761 | } |
| 762 | |
| 763 | public void seek(long pos) throws IOException { |
| 764 | checkClosed(); |
| 765 | |
| 766 | // This test also covers pos < 0 |
| 767 | if (pos < flushedPos) { |
| 768 | throw new IndexOutOfBoundsException("pos < flushedPos!"); |
| 769 | } |
| 770 | |
| 771 | this.streamPos = pos; |
| 772 | this.bitOffset = 0; |
| 773 | } |
| 774 | |
| 775 | /** |
| 776 | * Pushes the current stream position onto a stack of marked |
| 777 | * positions. |
| 778 | */ |
| 779 | public void mark() { |
| 780 | try { |
| 781 | markByteStack.push(new Long(getStreamPosition())); |
| 782 | markBitStack.push(new Integer(getBitOffset())); |
| 783 | } catch (IOException e) { |
| 784 | } |
| 785 | } |
| 786 | |
| 787 | /** |
| 788 | * Resets the current stream byte and bit positions from the stack |
| 789 | * of marked positions. |
| 790 | * |
| 791 | * <p> An <code>IOException</code> will be thrown if the previous |
| 792 | * marked position lies in the discarded portion of the stream. |
| 793 | * |
| 794 | * @exception IOException if an I/O error occurs. |
| 795 | */ |
| 796 | public void reset() throws IOException { |
| 797 | if (markByteStack.empty()) { |
| 798 | return; |
| 799 | } |
| 800 | |
| 801 | long pos = ((Long)markByteStack.pop()).longValue(); |
| 802 | if (pos < flushedPos) { |
| 803 | throw new IIOException |
| 804 | ("Previous marked position has been discarded!"); |
| 805 | } |
| 806 | seek(pos); |
| 807 | |
| 808 | int offset = ((Integer)markBitStack.pop()).intValue(); |
| 809 | setBitOffset(offset); |
| 810 | } |
| 811 | |
| 812 | public void flushBefore(long pos) throws IOException { |
| 813 | checkClosed(); |
| 814 | if (pos < flushedPos) { |
| 815 | throw new IndexOutOfBoundsException("pos < flushedPos!"); |
| 816 | } |
| 817 | if (pos > getStreamPosition()) { |
| 818 | throw new IndexOutOfBoundsException("pos > getStreamPosition()!"); |
| 819 | } |
| 820 | // Invariant: flushedPos >= 0 |
| 821 | flushedPos = pos; |
| 822 | } |
| 823 | |
| 824 | public void flush() throws IOException { |
| 825 | flushBefore(getStreamPosition()); |
| 826 | } |
| 827 | |
| 828 | public long getFlushedPosition() { |
| 829 | return flushedPos; |
| 830 | } |
| 831 | |
| 832 | /** |
| 833 | * Default implementation returns false. Subclasses should |
| 834 | * override this if they cache data. |
| 835 | */ |
| 836 | public boolean isCached() { |
| 837 | return false; |
| 838 | } |
| 839 | |
| 840 | /** |
| 841 | * Default implementation returns false. Subclasses should |
| 842 | * override this if they cache data in main memory. |
| 843 | */ |
| 844 | public boolean isCachedMemory() { |
| 845 | return false; |
| 846 | } |
| 847 | |
| 848 | /** |
| 849 | * Default implementation returns false. Subclasses should |
| 850 | * override this if they cache data in a temporary file. |
| 851 | */ |
| 852 | public boolean isCachedFile() { |
| 853 | return false; |
| 854 | } |
| 855 | |
| 856 | public void close() throws IOException { |
| 857 | checkClosed(); |
| 858 | |
| 859 | isClosed = true; |
| 860 | } |
| 861 | |
| 862 | /** |
| 863 | * Finalizes this object prior to garbage collection. The |
| 864 | * <code>close</code> method is called to close any open input |
| 865 | * source. This method should not be called from application |
| 866 | * code. |
| 867 | * |
| 868 | * @exception Throwable if an error occurs during superclass |
| 869 | * finalization. |
| 870 | */ |
| 871 | protected void finalize() throws Throwable { |
| 872 | if (!isClosed) { |
| 873 | try { |
| 874 | close(); |
| 875 | } catch (IOException e) { |
| 876 | } |
| 877 | } |
| 878 | super.finalize(); |
| 879 | } |
| 880 | } |