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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 | ||
f357bcd4 | 16 | package org.eclipse.tracecompass.ctf.core.event.io; |
486efb2e | 17 | |
5db5a3a4 AM |
18 | import static org.eclipse.tracecompass.common.core.NonNullUtils.checkNotNull; |
19 | ||
231c4e1f | 20 | import java.nio.BufferUnderflowException; |
486efb2e AM |
21 | import java.nio.ByteBuffer; |
22 | import java.nio.ByteOrder; | |
23 | ||
231c4e1f | 24 | import org.eclipse.jdt.annotation.NonNull; |
453a59f0 | 25 | import org.eclipse.tracecompass.ctf.core.CTFReaderException; |
db8e8f7d | 26 | |
486efb2e AM |
27 | /** |
28 | * <b><u>BitBuffer</u></b> | |
29 | * <p> | |
30 | * A bitwise buffer capable of accessing fields with bit offsets. | |
486efb2e | 31 | */ |
0594c61c | 32 | public final class BitBuffer { |
486efb2e AM |
33 | |
34 | // ------------------------------------------------------------------------ | |
35 | // Constants | |
36 | // ------------------------------------------------------------------------ | |
37 | ||
38 | /* default bit width */ | |
f068c622 MK |
39 | private static final int BIT_CHAR = Byte.SIZE; // yum |
40 | private static final int BYTE_MASK = (1 << BIT_CHAR) - 1; | |
41 | private static final int BIT_SHORT = Short.SIZE; | |
42 | private static final int SHORT_MASK = (1 << BIT_SHORT) - 1; | |
43 | private static final int BIT_INT = Integer.SIZE; | |
44 | private static final long INT_MASK = (1L << BIT_INT) - 1; | |
45 | private static final int BIT_LONG = Long.SIZE; | |
486efb2e AM |
46 | |
47 | // ------------------------------------------------------------------------ | |
48 | // Attributes | |
49 | // ------------------------------------------------------------------------ | |
50 | ||
91052124 MK |
51 | private final @NonNull ByteBuffer fBuffer; |
52 | private final long fBitCapacity; | |
231c4e1f MK |
53 | |
54 | /** | |
55 | * Bit-buffer's position, maximum value = Integer.MAX_VALUE * 8 | |
56 | */ | |
4c67e724 MK |
57 | private long fPosition; |
58 | private ByteOrder fByteOrder; | |
486efb2e AM |
59 | |
60 | // ------------------------------------------------------------------------ | |
61 | // Constructors | |
62 | // ------------------------------------------------------------------------ | |
63 | /** | |
74e4b6b9 | 64 | * Default constructor, makes a big-endian buffer |
486efb2e AM |
65 | */ |
66 | public BitBuffer() { | |
5db5a3a4 | 67 | this(checkNotNull(ByteBuffer.allocateDirect(0)), ByteOrder.BIG_ENDIAN); |
486efb2e AM |
68 | } |
69 | ||
70 | /** | |
74e4b6b9 | 71 | * Constructor, makes a big-endian buffer |
486efb2e AM |
72 | * |
73 | * @param buf | |
74 | * the bytebuffer to read | |
75 | */ | |
aefc5c83 | 76 | public BitBuffer(@NonNull ByteBuffer buf) { |
486efb2e AM |
77 | this(buf, ByteOrder.BIG_ENDIAN); |
78 | } | |
79 | ||
80 | /** | |
74e4b6b9 | 81 | * Constructor that is fully parameterizable |
486efb2e AM |
82 | * |
83 | * @param buf | |
84 | * the buffer to read | |
85 | * @param order | |
74e4b6b9 | 86 | * the byte order (big-endian, little-endian, network?) |
486efb2e | 87 | */ |
aefc5c83 | 88 | public BitBuffer(@NonNull ByteBuffer buf, ByteOrder order) { |
733c614c | 89 | fBuffer = buf; |
486efb2e | 90 | setByteOrder(order); |
4c67e724 | 91 | resetPosition(); |
b6dfd62a | 92 | fBitCapacity = (long) fBuffer.capacity() * BIT_CHAR; |
4c67e724 MK |
93 | } |
94 | ||
95 | private void resetPosition() { | |
96 | fPosition = 0; | |
486efb2e AM |
97 | } |
98 | ||
99 | // ------------------------------------------------------------------------ | |
100 | // 'Get' operations on buffer | |
101 | // ------------------------------------------------------------------------ | |
102 | ||
103 | /** | |
104 | * Relative <i>get</i> method for reading 32-bit integer. | |
105 | * | |
106 | * Reads next four bytes from the current bit position according to current | |
107 | * byte order. | |
108 | * | |
2b50c5ac | 109 | * @return The int value (signed) read from the buffer |
db8e8f7d | 110 | * @throws CTFReaderException |
2b50c5ac MK |
111 | * An error occurred reading the long. This exception can be |
112 | * raised if the buffer tries to read out of bounds | |
486efb2e | 113 | */ |
db8e8f7d | 114 | public int getInt() throws CTFReaderException { |
0594c61c | 115 | return getInt(BIT_INT, true); |
486efb2e AM |
116 | } |
117 | ||
2b50c5ac MK |
118 | /** |
119 | * Relative <i>get</i> method for reading 64-bit integer. | |
120 | * | |
121 | * Reads next eight bytes from the current bit position according to current | |
122 | * byte order. | |
123 | * | |
124 | * @return The long value (signed) read from the buffer | |
125 | * @throws CTFReaderException | |
126 | * An error occurred reading the long. This exception can be | |
127 | * raised if the buffer tries to read out of bounds | |
128 | */ | |
129 | public long getLong() throws CTFReaderException { | |
130 | return get(BIT_LONG, true); | |
131 | } | |
132 | ||
133 | /** | |
134 | * Relative <i>get</i> method for reading long of <i>length</i> bits. | |
135 | * | |
136 | * Reads <i>length</i> bits starting at the current position. The result is | |
137 | * signed extended if <i>signed</i> is true. The current position is | |
138 | * increased of <i>length</i> bits. | |
139 | * | |
140 | * @param length | |
141 | * The length in bits of this integer | |
142 | * @param signed | |
143 | * The sign extended flag | |
144 | * @return The long value read from the buffer | |
145 | * @throws CTFReaderException | |
146 | * An error occurred reading the data. If more than 64 bits at a | |
147 | * time are read, or the buffer is read beyond its end, this | |
148 | * exception will be raised. | |
149 | */ | |
150 | public long get(int length, boolean signed) throws CTFReaderException { | |
151 | if (length > BIT_LONG) { | |
152 | throw new CTFReaderException("Cannot read a long longer than 64 bits. Rquested: " + length); //$NON-NLS-1$ | |
153 | } | |
154 | if (length > BIT_INT) { | |
155 | final int highShift = length - BIT_INT; | |
156 | long a = getInt(); | |
157 | long b = getInt(highShift, false); | |
158 | long retVal; | |
159 | /* Cast the signed-extended int into a unsigned int. */ | |
f068c622 | 160 | a &= INT_MASK; |
2b50c5ac MK |
161 | b &= (1L << highShift) - 1L; |
162 | ||
4c67e724 | 163 | retVal = (fByteOrder == ByteOrder.BIG_ENDIAN) ? ((a << highShift) | b) : ((b << BIT_INT) | a); |
2b50c5ac MK |
164 | /* sign extend */ |
165 | if (signed) { | |
166 | int signExtendBits = BIT_LONG - length; | |
167 | retVal = (retVal << signExtendBits) >> signExtendBits; | |
168 | } | |
169 | return retVal; | |
170 | } | |
171 | long retVal = getInt(length, signed); | |
f068c622 | 172 | return (signed ? retVal : (retVal & INT_MASK)); |
2b50c5ac MK |
173 | } |
174 | ||
231c4e1f MK |
175 | /** |
176 | * Relative bulk <i>get</i> method. | |
177 | * | |
178 | * <p> | |
179 | * This method transfers <strong>bytes</strong> from this buffer into the | |
180 | * given destination array. This method currently only supports reads | |
181 | * aligned to 8 bytes. It is up to the developer to shift the bits in | |
182 | * post-processing to do unaligned reads. | |
183 | * | |
184 | * @param dst | |
185 | * the bytes to write to | |
186 | * @throws BufferUnderflowException | |
187 | * - If there are fewer than length bytes remaining in this | |
188 | * buffer | |
231c4e1f MK |
189 | */ |
190 | public void get(@NonNull byte[] dst) { | |
f068c622 | 191 | fBuffer.position((int) (fPosition / BIT_CHAR)); |
231c4e1f | 192 | fBuffer.get(dst); |
f068c622 | 193 | fPosition += dst.length * BIT_CHAR; |
231c4e1f MK |
194 | } |
195 | ||
486efb2e AM |
196 | /** |
197 | * Relative <i>get</i> method for reading integer of <i>length</i> bits. | |
198 | * | |
199 | * Reads <i>length</i> bits starting at the current position. The result is | |
200 | * signed extended if <i>signed</i> is true. The current position is | |
201 | * increased of <i>length</i> bits. | |
202 | * | |
203 | * @param length | |
204 | * The length in bits of this integer | |
205 | * @param signed | |
206 | * The sign extended flag | |
207 | * @return The int value read from the buffer | |
db8e8f7d AM |
208 | * @throws CTFReaderException |
209 | * An error occurred reading the data. When the buffer is read | |
210 | * beyond its end, this exception will be raised. | |
486efb2e | 211 | */ |
2b50c5ac | 212 | private int getInt(int length, boolean signed) throws CTFReaderException { |
74e4b6b9 EB |
213 | |
214 | /* Nothing to read. */ | |
486efb2e AM |
215 | if (length == 0) { |
216 | return 0; | |
217 | } | |
74e4b6b9 EB |
218 | |
219 | /* Validate that the buffer has enough bits. */ | |
220 | if (!canRead(length)) { | |
db8e8f7d AM |
221 | throw new CTFReaderException("Cannot read the integer, " + //$NON-NLS-1$ |
222 | "the buffer does not have enough remaining space. " + //$NON-NLS-1$ | |
223 | "Requested:" + length); //$NON-NLS-1$ | |
74e4b6b9 EB |
224 | } |
225 | ||
226 | /* Get the value from the byte buffer. */ | |
227 | int val = 0; | |
486efb2e AM |
228 | boolean gotIt = false; |
229 | ||
2b50c5ac MK |
230 | /* |
231 | * Try a fast read when the position is byte-aligned by using | |
232 | * java.nio.ByteBuffer's native methods | |
233 | */ | |
234 | /* | |
235 | * A faster alignment detection as the compiler cannot guaranty that pos | |
236 | * is always positive. | |
237 | */ | |
4c67e724 | 238 | if ((fPosition & (BitBuffer.BIT_CHAR - 1)) == 0) { |
486efb2e AM |
239 | switch (length) { |
240 | case BitBuffer.BIT_CHAR: | |
241 | // Byte | |
f068c622 | 242 | val = fBuffer.get((int) (fPosition / BIT_CHAR)); |
74e4b6b9 | 243 | if (!signed) { |
f068c622 | 244 | val = val & BYTE_MASK; |
486efb2e AM |
245 | } |
246 | gotIt = true; | |
247 | break; | |
248 | ||
249 | case BitBuffer.BIT_SHORT: | |
250 | // Word | |
f068c622 | 251 | val = fBuffer.getShort((int) (fPosition / BIT_CHAR)); |
74e4b6b9 | 252 | if (!signed) { |
f068c622 | 253 | val = val & SHORT_MASK; |
486efb2e AM |
254 | } |
255 | gotIt = true; | |
256 | break; | |
257 | ||
258 | case BitBuffer.BIT_INT: | |
259 | // Double word | |
f068c622 | 260 | val = fBuffer.getInt((int) (fPosition / BIT_CHAR)); |
486efb2e AM |
261 | gotIt = true; |
262 | break; | |
263 | ||
264 | default: | |
265 | break; | |
266 | } | |
267 | } | |
74e4b6b9 EB |
268 | |
269 | /* When not byte-aligned, fall-back to a general decoder. */ | |
486efb2e AM |
270 | if (!gotIt) { |
271 | // Nothing read yet: use longer methods | |
4c67e724 MK |
272 | if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { |
273 | val = getIntLE(fPosition, length, signed); | |
486efb2e | 274 | } else { |
4c67e724 | 275 | val = getIntBE(fPosition, length, signed); |
486efb2e AM |
276 | } |
277 | } | |
4c67e724 | 278 | fPosition += length; |
486efb2e AM |
279 | |
280 | return val; | |
281 | } | |
282 | ||
47ca6c05 | 283 | private int getIntBE(long index, int length, boolean signed) { |
c3ffbd61 MK |
284 | if ((length <= 0) || (length > BIT_INT)) { |
285 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
286 | } | |
47ca6c05 SM |
287 | long end = index + length; |
288 | int startByte = (int) (index / BIT_CHAR); | |
289 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
290 | int currByte, lshift, cshift, mask, cmask, cache; |
291 | int value = 0; | |
292 | ||
293 | currByte = startByte; | |
f068c622 | 294 | cache = fBuffer.get(currByte) & BYTE_MASK; |
486efb2e AM |
295 | boolean isNeg = (cache & (1 << (BIT_CHAR - (index % BIT_CHAR) - 1))) != 0; |
296 | if (signed && isNeg) { | |
297 | value = ~0; | |
298 | } | |
299 | if (startByte == (endByte - 1)) { | |
300 | cmask = cache >>> ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); | |
301 | if (((length) % BIT_CHAR) > 0) { | |
302 | mask = ~((~0) << length); | |
303 | cmask &= mask; | |
304 | } | |
305 | value <<= length; | |
306 | value |= cmask; | |
307 | return value; | |
308 | } | |
47ca6c05 | 309 | cshift = (int) (index % BIT_CHAR); |
486efb2e AM |
310 | if (cshift > 0) { |
311 | mask = ~((~0) << (BIT_CHAR - cshift)); | |
312 | cmask = cache & mask; | |
313 | lshift = BIT_CHAR - cshift; | |
314 | value <<= lshift; | |
315 | value |= cmask; | |
486efb2e AM |
316 | currByte++; |
317 | } | |
318 | for (; currByte < (endByte - 1); currByte++) { | |
319 | value <<= BIT_CHAR; | |
f068c622 | 320 | value |= fBuffer.get(currByte) & BYTE_MASK; |
486efb2e | 321 | } |
47ca6c05 | 322 | lshift = (int) (end % BIT_CHAR); |
486efb2e AM |
323 | if (lshift > 0) { |
324 | mask = ~((~0) << lshift); | |
f068c622 | 325 | cmask = fBuffer.get(currByte) & BYTE_MASK; |
486efb2e AM |
326 | cmask >>>= BIT_CHAR - lshift; |
327 | cmask &= mask; | |
328 | value <<= lshift; | |
329 | value |= cmask; | |
330 | } else { | |
331 | value <<= BIT_CHAR; | |
f068c622 | 332 | value |= fBuffer.get(currByte) & BYTE_MASK; |
486efb2e AM |
333 | } |
334 | return value; | |
335 | } | |
336 | ||
47ca6c05 | 337 | private int getIntLE(long index, int length, boolean signed) { |
c3ffbd61 MK |
338 | if ((length <= 0) || (length > BIT_INT)) { |
339 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
340 | } | |
47ca6c05 SM |
341 | long end = index + length; |
342 | int startByte = (int) (index / BIT_CHAR); | |
343 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
344 | int currByte, lshift, cshift, mask, cmask, cache, mod; |
345 | int value = 0; | |
346 | ||
347 | currByte = endByte - 1; | |
f068c622 | 348 | cache = fBuffer.get(currByte) & BYTE_MASK; |
47ca6c05 | 349 | mod = (int) (end % BIT_CHAR); |
486efb2e AM |
350 | lshift = (mod > 0) ? mod : BIT_CHAR; |
351 | boolean isNeg = (cache & (1 << (lshift - 1))) != 0; | |
352 | if (signed && isNeg) { | |
353 | value = ~0; | |
354 | } | |
355 | if (startByte == (endByte - 1)) { | |
356 | cmask = cache >>> (index % BIT_CHAR); | |
357 | if (((length) % BIT_CHAR) > 0) { | |
358 | mask = ~((~0) << length); | |
359 | cmask &= mask; | |
360 | } | |
361 | value <<= length; | |
362 | value |= cmask; | |
363 | return value; | |
364 | } | |
47ca6c05 | 365 | cshift = (int) (end % BIT_CHAR); |
486efb2e AM |
366 | if (cshift > 0) { |
367 | mask = ~((~0) << cshift); | |
368 | cmask = cache & mask; | |
369 | value <<= cshift; | |
370 | value |= cmask; | |
486efb2e AM |
371 | currByte--; |
372 | } | |
373 | for (; currByte >= (startByte + 1); currByte--) { | |
374 | value <<= BIT_CHAR; | |
f068c622 | 375 | value |= fBuffer.get(currByte) & BYTE_MASK; |
486efb2e | 376 | } |
47ca6c05 | 377 | lshift = (int) (index % BIT_CHAR); |
486efb2e AM |
378 | if (lshift > 0) { |
379 | mask = ~((~0) << (BIT_CHAR - lshift)); | |
f068c622 | 380 | cmask = fBuffer.get(currByte) & BYTE_MASK; |
486efb2e AM |
381 | cmask >>>= lshift; |
382 | cmask &= mask; | |
383 | value <<= (BIT_CHAR - lshift); | |
384 | value |= cmask; | |
385 | } else { | |
386 | value <<= BIT_CHAR; | |
f068c622 | 387 | value |= fBuffer.get(currByte) & BYTE_MASK; |
486efb2e AM |
388 | } |
389 | return value; | |
390 | } | |
391 | ||
392 | // ------------------------------------------------------------------------ | |
393 | // 'Put' operations on buffer | |
394 | // ------------------------------------------------------------------------ | |
395 | ||
396 | /** | |
397 | * Relative <i>put</i> method to write signed 32-bit integer. | |
398 | * | |
399 | * Write four bytes starting from current bit position in the buffer | |
400 | * according to the current byte order. The current position is increased of | |
401 | * <i>length</i> bits. | |
402 | * | |
403 | * @param value | |
404 | * The int value to write | |
db8e8f7d AM |
405 | * @throws CTFReaderException |
406 | * An error occurred writing the data. If the buffer is written | |
407 | * beyond its end, this exception will be raised. | |
486efb2e | 408 | */ |
db8e8f7d | 409 | public void putInt(int value) throws CTFReaderException { |
486efb2e AM |
410 | putInt(BIT_INT, value); |
411 | } | |
412 | ||
413 | /** | |
414 | * Relative <i>put</i> method to write <i>length</i> bits integer. | |
415 | * | |
416 | * Writes <i>length</i> lower-order bits from the provided <i>value</i>, | |
417 | * starting from current bit position in the buffer. Sequential bytes are | |
418 | * written according to the current byte order. The sign bit is carried to | |
419 | * the MSB if signed is true. The sign bit is included in <i>length</i>. The | |
420 | * current position is increased of <i>length</i>. | |
421 | * | |
422 | * @param length | |
423 | * The number of bits to write | |
424 | * @param value | |
425 | * The value to write | |
db8e8f7d AM |
426 | * @throws CTFReaderException |
427 | * An error occurred writing the data. If the buffer is written | |
428 | * beyond its end, this exception will be raised. | |
486efb2e | 429 | */ |
db8e8f7d | 430 | public void putInt(int length, int value) throws CTFReaderException { |
4c67e724 | 431 | final long curPos = fPosition; |
486efb2e AM |
432 | |
433 | if (!canRead(length)) { | |
db8e8f7d AM |
434 | throw new CTFReaderException("Cannot write to bitbuffer, " //$NON-NLS-1$ |
435 | + "insufficient space. Requested: " + length); //$NON-NLS-1$ | |
486efb2e AM |
436 | } |
437 | if (length == 0) { | |
438 | return; | |
439 | } | |
4c67e724 | 440 | if (fByteOrder == ByteOrder.LITTLE_ENDIAN) { |
486efb2e AM |
441 | putIntLE(curPos, length, value); |
442 | } else { | |
443 | putIntBE(curPos, length, value); | |
444 | } | |
4c67e724 | 445 | fPosition += length; |
486efb2e AM |
446 | } |
447 | ||
47ca6c05 | 448 | private void putIntBE(long index, int length, int value) { |
c3ffbd61 MK |
449 | if ((length <= 0) || (length > BIT_INT)) { |
450 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
451 | } | |
47ca6c05 SM |
452 | long end = index + length; |
453 | int startByte = (int) (index / BIT_CHAR); | |
454 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
455 | int currByte, lshift, cshift, mask, cmask; |
456 | int correctedValue = value; | |
457 | ||
458 | /* | |
459 | * mask v high bits. Works for unsigned and two complement signed | |
460 | * numbers which value do not overflow on length bits. | |
461 | */ | |
462 | ||
463 | if (length < BIT_INT) { | |
464 | correctedValue &= ~(~0 << length); | |
465 | } | |
466 | ||
467 | /* sub byte */ | |
468 | if (startByte == (endByte - 1)) { | |
47ca6c05 | 469 | lshift = (int) ((BIT_CHAR - (end % BIT_CHAR)) % BIT_CHAR); |
486efb2e AM |
470 | mask = ~((~0) << lshift); |
471 | if ((index % BIT_CHAR) > 0) { | |
472 | mask |= (~(0)) << (BIT_CHAR - (index % BIT_CHAR)); | |
473 | } | |
474 | cmask = correctedValue << lshift; | |
475 | /* | |
74e4b6b9 EB |
476 | * low bits are cleared because of left-shift and high bits are |
477 | * already cleared | |
486efb2e AM |
478 | */ |
479 | cmask &= ~mask; | |
f068c622 | 480 | int b = fBuffer.get(startByte) & BYTE_MASK; |
4c67e724 | 481 | fBuffer.put(startByte, (byte) ((b & mask) | cmask)); |
486efb2e AM |
482 | return; |
483 | } | |
484 | ||
485 | /* head byte contains MSB */ | |
486 | currByte = endByte - 1; | |
47ca6c05 | 487 | cshift = (int) (end % BIT_CHAR); |
486efb2e AM |
488 | if (cshift > 0) { |
489 | lshift = BIT_CHAR - cshift; | |
490 | mask = ~((~0) << lshift); | |
491 | cmask = correctedValue << lshift; | |
492 | cmask &= ~mask; | |
f068c622 | 493 | int b = fBuffer.get(currByte) & BYTE_MASK; |
4c67e724 | 494 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); |
486efb2e | 495 | correctedValue >>>= cshift; |
486efb2e AM |
496 | currByte--; |
497 | } | |
498 | ||
499 | /* middle byte(s) */ | |
500 | for (; currByte >= (startByte + 1); currByte--) { | |
4c67e724 | 501 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
502 | correctedValue >>>= BIT_CHAR; |
503 | } | |
504 | /* end byte contains LSB */ | |
505 | if ((index % BIT_CHAR) > 0) { | |
506 | mask = (~0) << (BIT_CHAR - (index % BIT_CHAR)); | |
507 | cmask = correctedValue & ~mask; | |
f068c622 | 508 | int b = fBuffer.get(currByte) & BYTE_MASK; |
4c67e724 | 509 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); |
486efb2e | 510 | } else { |
4c67e724 | 511 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
512 | } |
513 | } | |
514 | ||
47ca6c05 | 515 | private void putIntLE(long index, int length, int value) { |
c3ffbd61 MK |
516 | if ((length <= 0) || (length > BIT_INT)) { |
517 | throw new IllegalArgumentException("Length must be between 1-32 bits"); //$NON-NLS-1$ | |
518 | } | |
47ca6c05 SM |
519 | long end = index + length; |
520 | int startByte = (int) (index / BIT_CHAR); | |
521 | int endByte = (int) ((end + (BIT_CHAR - 1)) / BIT_CHAR); | |
486efb2e AM |
522 | int currByte, lshift, cshift, mask, cmask; |
523 | int correctedValue = value; | |
524 | ||
525 | /* | |
526 | * mask v high bits. Works for unsigned and two complement signed | |
527 | * numbers which value do not overflow on length bits. | |
528 | */ | |
529 | ||
530 | if (length < BIT_INT) { | |
531 | correctedValue &= ~(~0 << length); | |
532 | } | |
533 | ||
534 | /* sub byte */ | |
535 | if (startByte == (endByte - 1)) { | |
47ca6c05 | 536 | lshift = (int) (index % BIT_CHAR); |
486efb2e AM |
537 | mask = ~((~0) << lshift); |
538 | if ((end % BIT_CHAR) > 0) { | |
539 | mask |= (~(0)) << (end % BIT_CHAR); | |
540 | } | |
541 | cmask = correctedValue << lshift; | |
542 | /* | |
74e4b6b9 EB |
543 | * low bits are cleared because of left-shift and high bits are |
544 | * already cleared | |
486efb2e AM |
545 | */ |
546 | cmask &= ~mask; | |
f068c622 | 547 | int b = fBuffer.get(startByte) & BYTE_MASK; |
4c67e724 | 548 | fBuffer.put(startByte, (byte) ((b & mask) | cmask)); |
486efb2e AM |
549 | return; |
550 | } | |
551 | ||
552 | /* head byte */ | |
553 | currByte = startByte; | |
47ca6c05 | 554 | cshift = (int) (index % BIT_CHAR); |
486efb2e AM |
555 | if (cshift > 0) { |
556 | mask = ~((~0) << cshift); | |
557 | cmask = correctedValue << cshift; | |
558 | cmask &= ~mask; | |
f068c622 | 559 | int b = fBuffer.get(currByte) & BYTE_MASK; |
4c67e724 | 560 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); |
486efb2e | 561 | correctedValue >>>= BIT_CHAR - cshift; |
486efb2e AM |
562 | currByte++; |
563 | } | |
564 | ||
565 | /* middle byte(s) */ | |
566 | for (; currByte < (endByte - 1); currByte++) { | |
4c67e724 | 567 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
568 | correctedValue >>>= BIT_CHAR; |
569 | } | |
570 | /* end byte */ | |
571 | if ((end % BIT_CHAR) > 0) { | |
572 | mask = (~0) << (end % BIT_CHAR); | |
573 | cmask = correctedValue & ~mask; | |
f068c622 | 574 | int b = fBuffer.get(currByte) & BYTE_MASK; |
4c67e724 | 575 | fBuffer.put(currByte, (byte) ((b & mask) | cmask)); |
486efb2e | 576 | } else { |
4c67e724 | 577 | fBuffer.put(currByte, (byte) correctedValue); |
486efb2e AM |
578 | } |
579 | } | |
580 | ||
581 | // ------------------------------------------------------------------------ | |
582 | // Buffer attributes handling | |
583 | // ------------------------------------------------------------------------ | |
584 | ||
585 | /** | |
586 | * Can this buffer be read for thus amount of bits? | |
587 | * | |
588 | * @param length | |
589 | * the length in bits to read | |
590 | * @return does the buffer have enough room to read the next "length" | |
591 | */ | |
592 | public boolean canRead(int length) { | |
91052124 | 593 | return ((fPosition + length) <= fBitCapacity); |
486efb2e AM |
594 | } |
595 | ||
596 | /** | |
597 | * Sets the order of the buffer. | |
598 | * | |
599 | * @param order | |
600 | * The order of the buffer. | |
601 | */ | |
602 | public void setByteOrder(ByteOrder order) { | |
4c67e724 | 603 | fByteOrder = order; |
91052124 | 604 | fBuffer.order(order); |
486efb2e AM |
605 | } |
606 | ||
607 | /** | |
608 | * Sets the order of the buffer. | |
609 | * | |
610 | * @return The order of the buffer. | |
611 | */ | |
612 | public ByteOrder getByteOrder() { | |
4c67e724 | 613 | return fByteOrder; |
486efb2e AM |
614 | } |
615 | ||
616 | /** | |
617 | * Sets the position in the buffer. | |
618 | * | |
619 | * @param newPosition | |
620 | * The new position of the buffer. | |
4c67e724 MK |
621 | * @throws CTFReaderException |
622 | * Thrown on out of bounds exceptions | |
486efb2e | 623 | */ |
4c67e724 MK |
624 | public void position(long newPosition) throws CTFReaderException { |
625 | ||
91052124 | 626 | if (newPosition > fBitCapacity) { |
4c67e724 MK |
627 | throw new CTFReaderException("Out of bounds exception on a position move, attempting to access position: " + newPosition); //$NON-NLS-1$ |
628 | } | |
629 | fPosition = newPosition; | |
486efb2e AM |
630 | } |
631 | ||
632 | /** | |
633 | * | |
634 | * Sets the position in the buffer. | |
635 | * | |
636 | * @return order The position of the buffer. | |
637 | */ | |
47ca6c05 | 638 | public long position() { |
4c67e724 | 639 | return fPosition; |
486efb2e AM |
640 | } |
641 | ||
642 | /** | |
643 | * Sets the byte buffer | |
644 | * | |
645 | * @param buf | |
646 | * the byte buffer | |
647 | */ | |
733c614c | 648 | @Deprecated |
486efb2e | 649 | public void setByteBuffer(ByteBuffer buf) { |
733c614c MK |
650 | /* |
651 | * to avoid "The method setByteBuffer(ByteBuffer) from the type | |
652 | * BitBuffer can be declared as static" | |
653 | */ | |
654 | long data = fPosition; | |
655 | fPosition = data; | |
656 | throw new UnsupportedOperationException("Bytebuffers are now final"); //$NON-NLS-1$ | |
657 | ||
486efb2e AM |
658 | } |
659 | ||
660 | /** | |
661 | * Gets the byte buffer | |
662 | * | |
663 | * @return The byte buffer | |
664 | */ | |
665 | public ByteBuffer getByteBuffer() { | |
4c67e724 | 666 | return fBuffer; |
486efb2e AM |
667 | } |
668 | ||
669 | /** | |
74e4b6b9 | 670 | * Resets the bitbuffer. |
486efb2e AM |
671 | */ |
672 | public void clear() { | |
4c67e724 | 673 | resetPosition(); |
4c67e724 | 674 | fBuffer.clear(); |
486efb2e AM |
675 | } |
676 | ||
677 | } |