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486efb2e | 1 | /*******************************************************************************. |
733c614c | 2 | * Copyright (c) 2011, 2014 Ericsson, Ecole Polytechnique de Montreal and others |
486efb2e AM |
3 | * |
4 | * All rights reserved. This program and the accompanying materials are made | |
5 | * available under the terms of the Eclipse Public License v1.0 which | |
6 | * accompanies this distribution, and is available at | |
7 | * http://www.eclipse.org/legal/epl-v10.html | |
8 | * | |
2b50c5ac MK |
9 | * Contributors: |
10 | * Matthew Khouzam - Initial Design and implementation + overhaul | |
11 | * Francis Giraldeau - Initial API and implementation | |
12 | * Philippe Proulx - Some refinement and optimization | |
13 | * Etienne Bergeron <Etienne.Bergeron@gmail.com> - fix zero size read + cleanup | |
486efb2e AM |
14 | *******************************************************************************/ |
15 | ||
16 | package org.eclipse.linuxtools.ctf.core.event.io; | |
17 | ||
231c4e1f | 18 | import java.nio.BufferUnderflowException; |
486efb2e AM |
19 | import java.nio.ByteBuffer; |
20 | import java.nio.ByteOrder; | |
21 | ||
231c4e1f | 22 | import org.eclipse.jdt.annotation.NonNull; |
db8e8f7d AM |
23 | import org.eclipse.linuxtools.ctf.core.trace.CTFReaderException; |
24 | ||
486efb2e AM |
25 | /** |
26 | * <b><u>BitBuffer</u></b> | |
27 | * <p> | |
28 | * A bitwise buffer capable of accessing fields with bit offsets. | |
2b50c5ac | 29 | * |
486efb2e AM |
30 | * @since 2.0 |
31 | */ | |
0594c61c | 32 | public final class BitBuffer { |
486efb2e AM |
33 | |
34 | // ------------------------------------------------------------------------ | |
35 | // Constants | |
36 | // ------------------------------------------------------------------------ | |
37 | ||
38 | /* default bit width */ | |
39 | /** 8 bits to a char */ | |
40 | public static final int BIT_CHAR = 8; | |
41 | /** 16 bits to a short */ | |
42 | public static final int BIT_SHORT = 16; | |
43 | /** 32 bits to an int */ | |
44 | public static final int BIT_INT = 32; | |
45 | /** 32 bits to a float */ | |
46 | public static final int BIT_FLOAT = 32; | |
47 | /** 64 bits to a long */ | |
48 | public static final int BIT_LONG = 64; | |
49 | ||
50 | // ------------------------------------------------------------------------ | |
51 | // Attributes | |
52 | // ------------------------------------------------------------------------ | |
53 | ||
91052124 MK |
54 | private final @NonNull ByteBuffer fBuffer; |
55 | private final long fBitCapacity; | |
231c4e1f MK |
56 | |
57 | /** | |
58 | * Bit-buffer's position, maximum value = Integer.MAX_VALUE * 8 | |
59 | */ | |
4c67e724 MK |
60 | private long fPosition; |
61 | private ByteOrder fByteOrder; | |
486efb2e AM |
62 | |
63 | // ------------------------------------------------------------------------ | |
64 | // Constructors | |
65 | // ------------------------------------------------------------------------ | |
66 | /** | |
74e4b6b9 | 67 | * Default constructor, makes a big-endian buffer |
486efb2e | 68 | */ |
aefc5c83 | 69 | @SuppressWarnings("null") |
486efb2e | 70 | public BitBuffer() { |
aefc5c83 | 71 | this(ByteBuffer.allocateDirect(0), ByteOrder.BIG_ENDIAN); |
486efb2e AM |
72 | } |
73 | ||
74 | /** | |
74e4b6b9 | 75 | * Constructor, makes a big-endian buffer |
486efb2e AM |
76 | * |
77 | * @param buf | |
78 | * the bytebuffer to read | |
79 | */ | |
aefc5c83 | 80 | public BitBuffer(@NonNull ByteBuffer buf) { |
486efb2e AM |
81 | this(buf, ByteOrder.BIG_ENDIAN); |
82 | } | |
83 | ||
84 | /** | |
74e4b6b9 | 85 | * Constructor that is fully parameterizable |
486efb2e AM |
86 | * |
87 | * @param buf | |
88 | * the buffer to read | |
89 | * @param order | |
74e4b6b9 | 90 | * the byte order (big-endian, little-endian, network?) |
486efb2e | 91 | */ |
aefc5c83 | 92 | public BitBuffer(@NonNull ByteBuffer buf, ByteOrder order) { |
733c614c | 93 | fBuffer = buf; |
486efb2e | 94 | setByteOrder(order); |
4c67e724 | 95 | resetPosition(); |
91052124 | 96 | fBitCapacity = fBuffer.capacity() * BIT_CHAR; |
4c67e724 MK |
97 | } |
98 | ||
99 | private void resetPosition() { | |
100 | fPosition = 0; | |
486efb2e AM |
101 | } |
102 | ||
103 | // ------------------------------------------------------------------------ | |
104 | // 'Get' operations on buffer | |
105 | // ------------------------------------------------------------------------ | |
106 | ||
107 | /** | |
108 | * Relative <i>get</i> method for reading 32-bit integer. | |
109 | * | |
110 | * Reads next four bytes from the current bit position according to current | |
111 | * byte order. | |
112 | * | |
2b50c5ac | 113 | * @return The int value (signed) read from the buffer |
db8e8f7d | 114 | * @throws CTFReaderException |
2b50c5ac MK |
115 | * An error occurred reading the long. This exception can be |
116 | * raised if the buffer tries to read out of bounds | |
486efb2e | 117 | */ |
db8e8f7d | 118 | public int getInt() throws CTFReaderException { |
0594c61c | 119 | return getInt(BIT_INT, true); |
486efb2e AM |
120 | } |
121 | ||
2b50c5ac MK |
122 | /** |
123 | * Relative <i>get</i> method for reading 64-bit integer. | |
124 | * | |
125 | * Reads next eight bytes from the current bit position according to current | |
126 | * byte order. | |
127 | * | |
128 | * @return The long value (signed) read from the buffer | |
129 | * @throws CTFReaderException | |
130 | * An error occurred reading the long. This exception can be | |
131 | * raised if the buffer tries to read out of bounds | |
c4767854 | 132 | * @since 3.0 |
2b50c5ac MK |
133 | */ |
134 | public long getLong() throws CTFReaderException { | |
135 | return get(BIT_LONG, true); | |
136 | } | |
137 | ||
138 | /** | |
139 | * Relative <i>get</i> method for reading long of <i>length</i> bits. | |
140 | * | |
141 | * Reads <i>length</i> bits starting at the current position. The result is | |
142 | * signed extended if <i>signed</i> is true. The current position is | |
143 | * increased of <i>length</i> bits. | |
144 | * | |
145 | * @param length | |
146 | * The length in bits of this integer | |
147 | * @param signed | |
148 | * The sign extended flag | |
149 | * @return The long value read from the buffer | |
150 | * @throws CTFReaderException | |
151 | * An error occurred reading the data. If more than 64 bits at a | |
152 | * time are read, or the buffer is read beyond its end, this | |
153 | * exception will be raised. | |
c4767854 | 154 | * @since 3.0 |
2b50c5ac MK |
155 | */ |
156 | public long get(int length, boolean signed) throws CTFReaderException { | |
157 | if (length > BIT_LONG) { | |
158 | throw new CTFReaderException("Cannot read a long longer than 64 bits. Rquested: " + length); //$NON-NLS-1$ | |
159 | } | |
160 | if (length > BIT_INT) { | |
161 | final int highShift = length - BIT_INT; | |
162 | long a = getInt(); | |
163 | long b = getInt(highShift, false); | |
164 | long retVal; | |
165 | /* Cast the signed-extended int into a unsigned int. */ | |
166 | a &= 0xFFFFFFFFL; | |
167 | b &= (1L << highShift) - 1L; | |
168 | ||
4c67e724 | 169 | retVal = (fByteOrder == ByteOrder.BIG_ENDIAN) ? ((a << highShift) | b) : ((b << BIT_INT) | a); |
2b50c5ac MK |
170 | /* sign extend */ |
171 | if (signed) { | |
172 | int signExtendBits = BIT_LONG - length; | |
173 | retVal = (retVal << signExtendBits) >> signExtendBits; | |
174 | } | |
175 | return retVal; | |
176 | } | |
177 | long retVal = getInt(length, signed); | |
178 | return (signed ? retVal : (retVal & 0xFFFFFFFFL)); | |
179 | } | |
180 | ||
231c4e1f MK |
181 | /** |
182 | * Relative bulk <i>get</i> method. | |
183 | * | |
184 | * <p> | |
185 | * This method transfers <strong>bytes</strong> from this buffer into the | |
186 | * given destination array. This method currently only supports reads | |
187 | * aligned to 8 bytes. It is up to the developer to shift the bits in | |
188 | * post-processing to do unaligned reads. | |
189 | * | |
190 | * @param dst | |
191 | * the bytes to write to | |
192 | * @throws BufferUnderflowException | |
193 | * - If there are fewer than length bytes remaining in this | |
194 | * buffer | |
195 | * @since 3.1 | |
196 | */ | |
197 | public void get(@NonNull byte[] dst) { | |
198 | fBuffer.position((int) (fPosition / 8)); | |
199 | fBuffer.get(dst); | |
200 | fPosition += dst.length * 8; | |
201 | } | |
202 | ||
486efb2e AM |
203 | /** |
204 | * Relative <i>get</i> method for reading integer of <i>length</i> bits. | |
205 | * | |
206 | * Reads <i>length</i> bits starting at the current position. The result is | |
207 | * signed extended if <i>signed</i> is true. The current position is | |
208 | * increased of <i>length</i> bits. | |
209 | * | |
210 | * @param length | |
211 | * The length in bits of this integer | |
212 | * @param signed | |
213 | * The sign extended flag | |
214 | * @return The int value read from the buffer | |
db8e8f7d AM |
215 | * @throws CTFReaderException |
216 | * An error occurred reading the data. When the buffer is read | |
217 | * beyond its end, this exception will be raised. | |
486efb2e | 218 | */ |
2b50c5ac | 219 | private int getInt(int length, boolean signed) throws CTFReaderException { |
74e4b6b9 EB |
220 | |
221 | /* Nothing to read. */ | |
486efb2e AM |
222 | if (length == 0) { |
223 | return 0; | |
224 | } | |
74e4b6b9 EB |
225 | |
226 | /* Validate that the buffer has enough bits. */ | |
227 | if (!canRead(length)) { | |
db8e8f7d AM |
228 | throw new CTFReaderException("Cannot read the integer, " + //$NON-NLS-1$ |
229 | "the buffer does not have enough remaining space. " + //$NON-NLS-1$ | |
230 | "Requested:" + length); //$NON-NLS-1$ | |
74e4b6b9 EB |
231 | } |
232 | ||
233 | /* Get the value from the byte buffer. */ | |
234 | int val = 0; | |
486efb2e AM |
235 | boolean gotIt = false; |
236 | ||
2b50c5ac MK |
237 | /* |
238 | * Try a fast read when the position is byte-aligned by using | |
239 | * java.nio.ByteBuffer's native methods | |
240 | */ | |
241 | /* | |
242 | * A faster alignment detection as the compiler cannot guaranty that pos | |
243 | * is always positive. | |
244 | */ | |
4c67e724 | 245 | if ((fPosition & (BitBuffer.BIT_CHAR - 1)) == 0) { |
486efb2e AM |
246 | switch (length) { |
247 | case BitBuffer.BIT_CHAR: | |
248 | // Byte | |
4c67e724 | 249 | val = fBuffer.get((int) (fPosition / 8)); |
74e4b6b9 EB |
250 | if (!signed) { |
251 | val = val & 0xff; | |
486efb2e AM |
252 | } |
253 | gotIt = true; | |
254 | break; | |
255 | ||
256 | case BitBuffer.BIT_SHORT: | |
257 | // Word | |
4c67e724 | 258 | val = fBuffer.getShort((int) (fPosition / 8)); |
74e4b6b9 EB |
259 | if (!signed) { |
260 | val = val & 0xffff; | |
486efb2e AM |
261 | } |
262 | gotIt = true; | |
263 | break; | |
264 | ||
265 | case BitBuffer.BIT_INT: | |
266 | // Double word | |
4c67e724 | 267 | val = fBuffer.getInt((int) (fPosition / 8)); |
486efb2e AM |
268 | gotIt = true; |
269 | break; | |
270 | ||
271 | default: | |
272 | break; | |
273 | } | |
274 | } | |
74e4b6b9 EB |
275 | |
276 | /* When not byte-aligned, fall-back to a general decoder. */ | |
486efb2e AM |
277 | if (!gotIt) { |
278 | // Nothing read yet: use longer methods | |
4c67e724 MK |
279 | if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { |
280 | val = getIntLE(fPosition, length, signed); | |
486efb2e | 281 | } else { |
4c67e724 | 282 | val = getIntBE(fPosition, length, signed); |
486efb2e AM |
283 | } |
284 | } | |
4c67e724 | 285 | fPosition += length; |
486efb2e AM |
286 | |
287 | return val; | |
288 | } | |
289 | ||
47ca6c05 | 290 | private int getIntBE(long index, int length, boolean signed) { |
c3ffbd61 MK |
291 | if ((length <= 0) || (length > BIT_INT)) { |
292 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
293 | } | |
47ca6c05 SM |
294 | long end = index + length; |
295 | int startByte = (int) (index / BIT_CHAR); | |
296 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
297 | int currByte, lshift, cshift, mask, cmask, cache; |
298 | int value = 0; | |
299 | ||
300 | currByte = startByte; | |
4c67e724 | 301 | cache = fBuffer.get(currByte) & 0xFF; |
486efb2e AM |
302 | boolean isNeg = (cache & (1 << (BIT_CHAR - (index % BIT_CHAR) - 1))) != 0; |
303 | if (signed && isNeg) { | |
304 | value = ~0; | |
305 | } | |
306 | if (startByte == (endByte - 1)) { | |
307 | cmask = cache >>> ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); | |
308 | if (((length) % BIT_CHAR) > 0) { | |
309 | mask = ~((~0) << length); | |
310 | cmask &= mask; | |
311 | } | |
312 | value <<= length; | |
313 | value |= cmask; | |
314 | return value; | |
315 | } | |
47ca6c05 | 316 | cshift = (int) (index % BIT_CHAR); |
486efb2e AM |
317 | if (cshift > 0) { |
318 | mask = ~((~0) << (BIT_CHAR - cshift)); | |
319 | cmask = cache & mask; | |
320 | lshift = BIT_CHAR - cshift; | |
321 | value <<= lshift; | |
322 | value |= cmask; | |
486efb2e AM |
323 | currByte++; |
324 | } | |
325 | for (; currByte < (endByte - 1); currByte++) { | |
326 | value <<= BIT_CHAR; | |
4c67e724 | 327 | value |= fBuffer.get(currByte) & 0xFF; |
486efb2e | 328 | } |
47ca6c05 | 329 | lshift = (int) (end % BIT_CHAR); |
486efb2e AM |
330 | if (lshift > 0) { |
331 | mask = ~((~0) << lshift); | |
4c67e724 | 332 | cmask = fBuffer.get(currByte) & 0xFF; |
486efb2e AM |
333 | cmask >>>= BIT_CHAR - lshift; |
334 | cmask &= mask; | |
335 | value <<= lshift; | |
336 | value |= cmask; | |
337 | } else { | |
338 | value <<= BIT_CHAR; | |
4c67e724 | 339 | value |= fBuffer.get(currByte) & 0xFF; |
486efb2e AM |
340 | } |
341 | return value; | |
342 | } | |
343 | ||
47ca6c05 | 344 | private int getIntLE(long index, int length, boolean signed) { |
c3ffbd61 MK |
345 | if ((length <= 0) || (length > BIT_INT)) { |
346 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
347 | } | |
47ca6c05 SM |
348 | long end = index + length; |
349 | int startByte = (int) (index / BIT_CHAR); | |
350 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
351 | int currByte, lshift, cshift, mask, cmask, cache, mod; |
352 | int value = 0; | |
353 | ||
354 | currByte = endByte - 1; | |
4c67e724 | 355 | cache = fBuffer.get(currByte) & 0xFF; |
47ca6c05 | 356 | mod = (int) (end % BIT_CHAR); |
486efb2e AM |
357 | lshift = (mod > 0) ? mod : BIT_CHAR; |
358 | boolean isNeg = (cache & (1 << (lshift - 1))) != 0; | |
359 | if (signed && isNeg) { | |
360 | value = ~0; | |
361 | } | |
362 | if (startByte == (endByte - 1)) { | |
363 | cmask = cache >>> (index % BIT_CHAR); | |
364 | if (((length) % BIT_CHAR) > 0) { | |
365 | mask = ~((~0) << length); | |
366 | cmask &= mask; | |
367 | } | |
368 | value <<= length; | |
369 | value |= cmask; | |
370 | return value; | |
371 | } | |
47ca6c05 | 372 | cshift = (int) (end % BIT_CHAR); |
486efb2e AM |
373 | if (cshift > 0) { |
374 | mask = ~((~0) << cshift); | |
375 | cmask = cache & mask; | |
376 | value <<= cshift; | |
377 | value |= cmask; | |
486efb2e AM |
378 | currByte--; |
379 | } | |
380 | for (; currByte >= (startByte + 1); currByte--) { | |
381 | value <<= BIT_CHAR; | |
4c67e724 | 382 | value |= fBuffer.get(currByte) & 0xFF; |
486efb2e | 383 | } |
47ca6c05 | 384 | lshift = (int) (index % BIT_CHAR); |
486efb2e AM |
385 | if (lshift > 0) { |
386 | mask = ~((~0) << (BIT_CHAR - lshift)); | |
4c67e724 | 387 | cmask = fBuffer.get(currByte) & 0xFF; |
486efb2e AM |
388 | cmask >>>= lshift; |
389 | cmask &= mask; | |
390 | value <<= (BIT_CHAR - lshift); | |
391 | value |= cmask; | |
392 | } else { | |
393 | value <<= BIT_CHAR; | |
4c67e724 | 394 | value |= fBuffer.get(currByte) & 0xFF; |
486efb2e AM |
395 | } |
396 | return value; | |
397 | } | |
398 | ||
399 | // ------------------------------------------------------------------------ | |
400 | // 'Put' operations on buffer | |
401 | // ------------------------------------------------------------------------ | |
402 | ||
403 | /** | |
404 | * Relative <i>put</i> method to write signed 32-bit integer. | |
405 | * | |
406 | * Write four bytes starting from current bit position in the buffer | |
407 | * according to the current byte order. The current position is increased of | |
408 | * <i>length</i> bits. | |
409 | * | |
410 | * @param value | |
411 | * The int value to write | |
db8e8f7d AM |
412 | * @throws CTFReaderException |
413 | * An error occurred writing the data. If the buffer is written | |
414 | * beyond its end, this exception will be raised. | |
486efb2e | 415 | */ |
db8e8f7d | 416 | public void putInt(int value) throws CTFReaderException { |
486efb2e AM |
417 | putInt(BIT_INT, value); |
418 | } | |
419 | ||
420 | /** | |
421 | * Relative <i>put</i> method to write <i>length</i> bits integer. | |
422 | * | |
423 | * Writes <i>length</i> lower-order bits from the provided <i>value</i>, | |
424 | * starting from current bit position in the buffer. Sequential bytes are | |
425 | * written according to the current byte order. The sign bit is carried to | |
426 | * the MSB if signed is true. The sign bit is included in <i>length</i>. The | |
427 | * current position is increased of <i>length</i>. | |
428 | * | |
429 | * @param length | |
430 | * The number of bits to write | |
431 | * @param value | |
432 | * The value to write | |
db8e8f7d AM |
433 | * @throws CTFReaderException |
434 | * An error occurred writing the data. If the buffer is written | |
435 | * beyond its end, this exception will be raised. | |
486efb2e | 436 | */ |
db8e8f7d | 437 | public void putInt(int length, int value) throws CTFReaderException { |
4c67e724 | 438 | final long curPos = fPosition; |
486efb2e AM |
439 | |
440 | if (!canRead(length)) { | |
db8e8f7d AM |
441 | throw new CTFReaderException("Cannot write to bitbuffer, " //$NON-NLS-1$ |
442 | + "insufficient space. Requested: " + length); //$NON-NLS-1$ | |
486efb2e AM |
443 | } |
444 | if (length == 0) { | |
445 | return; | |
446 | } | |
4c67e724 | 447 | if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { |
486efb2e AM |
448 | putIntLE(curPos, length, value); |
449 | } else { | |
450 | putIntBE(curPos, length, value); | |
451 | } | |
4c67e724 | 452 | fPosition += length; |
486efb2e AM |
453 | } |
454 | ||
47ca6c05 | 455 | private void putIntBE(long index, int length, int value) { |
c3ffbd61 MK |
456 | if ((length <= 0) || (length > BIT_INT)) { |
457 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
458 | } | |
47ca6c05 SM |
459 | long end = index + length; |
460 | int startByte = (int) (index / BIT_CHAR); | |
461 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
462 | int currByte, lshift, cshift, mask, cmask; |
463 | int correctedValue = value; | |
464 | ||
465 | /* | |
466 | * mask v high bits. Works for unsigned and two complement signed | |
467 | * numbers which value do not overflow on length bits. | |
468 | */ | |
469 | ||
470 | if (length < BIT_INT) { | |
471 | correctedValue &= ~(~0 << length); | |
472 | } | |
473 | ||
474 | /* sub byte */ | |
475 | if (startByte == (endByte - 1)) { | |
47ca6c05 | 476 | lshift = (int) ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); |
486efb2e AM |
477 | mask = ~((~0) << lshift); |
478 | if ((index % BIT_CHAR) > 0) { | |
479 | mask |= (~(0)) << (BIT_CHAR - (index % BIT_CHAR)); | |
480 | } | |
481 | cmask = correctedValue << lshift; | |
482 | /* | |
74e4b6b9 EB |
483 | * low bits are cleared because of left-shift and high bits are |
484 | * already cleared | |
486efb2e AM |
485 | */ |
486 | cmask &= ~mask; | |
4c67e724 MK |
487 | int b = fBuffer.get(startByte) & 0xFF; |
488 | fBuffer.put(startByte, (byte) ((b & mask) | cmask)); | |
486efb2e AM |
489 | return; |
490 | } | |
491 | ||
492 | /* head byte contains MSB */ | |
493 | currByte = endByte - 1; | |
47ca6c05 | 494 | cshift = (int) (end % BIT_CHAR); |
486efb2e AM |
495 | if (cshift > 0) { |
496 | lshift = BIT_CHAR - cshift; | |
497 | mask = ~((~0) << lshift); | |
498 | cmask = correctedValue << lshift; | |
499 | cmask &= ~mask; | |
4c67e724 MK |
500 | int b = fBuffer.get(currByte) & 0xFF; |
501 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); | |
486efb2e | 502 | correctedValue >>>= cshift; |
486efb2e AM |
503 | currByte--; |
504 | } | |
505 | ||
506 | /* middle byte(s) */ | |
507 | for (; currByte >= (startByte + 1); currByte--) { | |
4c67e724 | 508 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
509 | correctedValue >>>= BIT_CHAR; |
510 | } | |
511 | /* end byte contains LSB */ | |
512 | if ((index % BIT_CHAR) > 0) { | |
513 | mask = (~0) << (BIT_CHAR - (index % BIT_CHAR)); | |
514 | cmask = correctedValue & ~mask; | |
4c67e724 MK |
515 | int b = fBuffer.get(currByte) & 0xFF; |
516 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); | |
486efb2e | 517 | } else { |
4c67e724 | 518 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
519 | } |
520 | } | |
521 | ||
47ca6c05 | 522 | private void putIntLE(long index, int length, int value) { |
c3ffbd61 MK |
523 | if ((length <= 0) || (length > BIT_INT)) { |
524 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
525 | } | |
47ca6c05 SM |
526 | long end = index + length; |
527 | int startByte = (int) (index / BIT_CHAR); | |
528 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
529 | int currByte, lshift, cshift, mask, cmask; |
530 | int correctedValue = value; | |
531 | ||
532 | /* | |
533 | * mask v high bits. Works for unsigned and two complement signed | |
534 | * numbers which value do not overflow on length bits. | |
535 | */ | |
536 | ||
537 | if (length < BIT_INT) { | |
538 | correctedValue &= ~(~0 << length); | |
539 | } | |
540 | ||
541 | /* sub byte */ | |
542 | if (startByte == (endByte - 1)) { | |
47ca6c05 | 543 | lshift = (int) (index % BIT_CHAR); |
486efb2e AM |
544 | mask = ~((~0) << lshift); |
545 | if ((end % BIT_CHAR) > 0) { | |
546 | mask |= (~(0)) << (end % BIT_CHAR); | |
547 | } | |
548 | cmask = correctedValue << lshift; | |
549 | /* | |
74e4b6b9 EB |
550 | * low bits are cleared because of left-shift and high bits are |
551 | * already cleared | |
486efb2e AM |
552 | */ |
553 | cmask &= ~mask; | |
4c67e724 MK |
554 | int b = fBuffer.get(startByte) & 0xFF; |
555 | fBuffer.put(startByte, (byte) ((b & mask) | cmask)); | |
486efb2e AM |
556 | return; |
557 | } | |
558 | ||
559 | /* head byte */ | |
560 | currByte = startByte; | |
47ca6c05 | 561 | cshift = (int) (index % BIT_CHAR); |
486efb2e AM |
562 | if (cshift > 0) { |
563 | mask = ~((~0) << cshift); | |
564 | cmask = correctedValue << cshift; | |
565 | cmask &= ~mask; | |
4c67e724 MK |
566 | int b = fBuffer.get(currByte) & 0xFF; |
567 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); | |
486efb2e | 568 | correctedValue >>>= BIT_CHAR - cshift; |
486efb2e AM |
569 | currByte++; |
570 | } | |
571 | ||
572 | /* middle byte(s) */ | |
573 | for (; currByte < (endByte - 1); currByte++) { | |
4c67e724 | 574 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
575 | correctedValue >>>= BIT_CHAR; |
576 | } | |
577 | /* end byte */ | |
578 | if ((end % BIT_CHAR) > 0) { | |
579 | mask = (~0) << (end % BIT_CHAR); | |
580 | cmask = correctedValue & ~mask; | |
4c67e724 MK |
581 | int b = fBuffer.get(currByte) & 0xFF; |
582 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); | |
486efb2e | 583 | } else { |
4c67e724 | 584 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
585 | } |
586 | } | |
587 | ||
588 | // ------------------------------------------------------------------------ | |
589 | // Buffer attributes handling | |
590 | // ------------------------------------------------------------------------ | |
591 | ||
592 | /** | |
593 | * Can this buffer be read for thus amount of bits? | |
594 | * | |
595 | * @param length | |
596 | * the length in bits to read | |
597 | * @return does the buffer have enough room to read the next "length" | |
598 | */ | |
599 | public boolean canRead(int length) { | |
91052124 | 600 | return ((fPosition + length) <= fBitCapacity); |
486efb2e AM |
601 | } |
602 | ||
603 | /** | |
604 | * Sets the order of the buffer. | |
605 | * | |
606 | * @param order | |
607 | * The order of the buffer. | |
608 | */ | |
609 | public void setByteOrder(ByteOrder order) { | |
4c67e724 | 610 | fByteOrder = order; |
91052124 | 611 | fBuffer.order(order); |
486efb2e AM |
612 | } |
613 | ||
614 | /** | |
615 | * Sets the order of the buffer. | |
616 | * | |
617 | * @return The order of the buffer. | |
618 | */ | |
619 | public ByteOrder getByteOrder() { | |
4c67e724 | 620 | return fByteOrder; |
486efb2e AM |
621 | } |
622 | ||
623 | /** | |
624 | * Sets the position in the buffer. | |
625 | * | |
626 | * @param newPosition | |
627 | * The new position of the buffer. | |
4c67e724 MK |
628 | * @throws CTFReaderException |
629 | * Thrown on out of bounds exceptions | |
c4767854 | 630 | * @since 3.0 |
486efb2e | 631 | */ |
4c67e724 MK |
632 | public void position(long newPosition) throws CTFReaderException { |
633 | ||
91052124 MK |
634 | |
635 | if (newPosition > fBitCapacity) { | |
4c67e724 MK |
636 | throw new CTFReaderException("Out of bounds exception on a position move, attempting to access position: " + newPosition); //$NON-NLS-1$ |
637 | } | |
638 | fPosition = newPosition; | |
486efb2e AM |
639 | } |
640 | ||
641 | /** | |
642 | * | |
643 | * Sets the position in the buffer. | |
644 | * | |
645 | * @return order The position of the buffer. | |
c4767854 | 646 | * @since 3.0 |
486efb2e | 647 | */ |
47ca6c05 | 648 | public long position() { |
4c67e724 | 649 | return fPosition; |
486efb2e AM |
650 | } |
651 | ||
652 | /** | |
653 | * Sets the byte buffer | |
654 | * | |
655 | * @param buf | |
656 | * the byte buffer | |
657 | */ | |
733c614c | 658 | @Deprecated |
486efb2e | 659 | public void setByteBuffer(ByteBuffer buf) { |
733c614c MK |
660 | /* |
661 | * to avoid "The method setByteBuffer(ByteBuffer) from the type | |
662 | * BitBuffer can be declared as static" | |
663 | */ | |
664 | long data = fPosition; | |
665 | fPosition = data; | |
666 | throw new UnsupportedOperationException("Bytebuffers are now final"); //$NON-NLS-1$ | |
667 | ||
486efb2e AM |
668 | } |
669 | ||
670 | /** | |
671 | * Gets the byte buffer | |
672 | * | |
673 | * @return The byte buffer | |
674 | */ | |
675 | public ByteBuffer getByteBuffer() { | |
4c67e724 | 676 | return fBuffer; |
486efb2e AM |
677 | } |
678 | ||
679 | /** | |
74e4b6b9 | 680 | * Resets the bitbuffer. |
486efb2e AM |
681 | */ |
682 | public void clear() { | |
4c67e724 | 683 | resetPosition(); |
4c67e724 | 684 | fBuffer.clear(); |
486efb2e AM |
685 | } |
686 | ||
687 | } |