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40 | |
41 | #include "qbitarray.h" |
42 | #include <qalgorithms.h> |
43 | #include <qdatastream.h> |
44 | #include <qdebug.h> |
45 | #include <qendian.h> |
46 | #include <string.h> |
47 | |
48 | QT_BEGIN_NAMESPACE |
49 | |
50 | /*! |
51 | \class QBitArray |
52 | \inmodule QtCore |
53 | \brief The QBitArray class provides an array of bits. |
54 | |
55 | \ingroup tools |
56 | \ingroup shared |
57 | \reentrant |
58 | |
59 | A QBitArray is an array that gives access to individual bits and |
60 | provides operators (\l{operator&()}{AND}, \l{operator|()}{OR}, |
61 | \l{operator^()}{XOR}, and \l{operator~()}{NOT}) that work on |
62 | entire arrays of bits. It uses \l{implicit sharing} (copy-on-write) |
63 | to reduce memory usage and to avoid the needless copying of data. |
64 | |
65 | The following code constructs a QBitArray containing 200 bits |
66 | initialized to false (0): |
67 | |
68 | \snippet code/src_corelib_tools_qbitarray.cpp 0 |
69 | |
70 | To initialize the bits to true, either pass \c true as second |
71 | argument to the constructor, or call fill() later on. |
72 | |
73 | QBitArray uses 0-based indexes, just like C++ arrays. To access |
74 | the bit at a particular index position, you can use operator[](). |
75 | On non-const bit arrays, operator[]() returns a reference to a |
76 | bit that can be used on the left side of an assignment. For |
77 | example: |
78 | |
79 | \snippet code/src_corelib_tools_qbitarray.cpp 1 |
80 | |
81 | For technical reasons, it is more efficient to use testBit() and |
82 | setBit() to access bits in the array than operator[](). For |
83 | example: |
84 | |
85 | \snippet code/src_corelib_tools_qbitarray.cpp 2 |
86 | |
87 | QBitArray supports \c{&} (\l{operator&()}{AND}), \c{|} |
88 | (\l{operator|()}{OR}), \c{^} (\l{operator^()}{XOR}), |
89 | \c{~} (\l{operator~()}{NOT}), as well as |
90 | \c{&=}, \c{|=}, and \c{^=}. These operators work in the same way |
91 | as the built-in C++ bitwise operators of the same name. For |
92 | example: |
93 | |
94 | \snippet code/src_corelib_tools_qbitarray.cpp 3 |
95 | |
96 | For historical reasons, QBitArray distinguishes between a null |
97 | bit array and an empty bit array. A \e null bit array is a bit |
98 | array that is initialized using QBitArray's default constructor. |
99 | An \e empty bit array is any bit array with size 0. A null bit |
100 | array is always empty, but an empty bit array isn't necessarily |
101 | null: |
102 | |
103 | \snippet code/src_corelib_tools_qbitarray.cpp 4 |
104 | |
105 | All functions except isNull() treat null bit arrays the same as |
106 | empty bit arrays; for example, QBitArray() compares equal to |
107 | QBitArray(0). We recommend that you always use isEmpty() and |
108 | avoid isNull(). |
109 | |
110 | \sa QByteArray, QVector |
111 | */ |
112 | |
113 | /*! |
114 | \fn QBitArray::QBitArray(QBitArray &&other) |
115 | |
116 | Move-constructs a QBitArray instance, making it point at the same |
117 | object that \a other was pointing to. |
118 | |
119 | \since 5.2 |
120 | */ |
121 | |
122 | /*! \fn QBitArray::QBitArray() |
123 | |
124 | Constructs an empty bit array. |
125 | |
126 | \sa isEmpty() |
127 | */ |
128 | |
129 | /* |
130 | * QBitArray construction note: |
131 | * |
132 | * We overallocate the byte array by 1 byte. The first user bit is at |
133 | * d.data()[1]. On the extra first byte, we store the difference between the |
134 | * number of bits in the byte array (including this byte) and the number of |
135 | * bits in the bit array. Therefore, for a non-empty QBitArray, it's always a |
136 | * number between 8 and 15. For the empty one, d is the an empty QByteArray and |
137 | * *d.constData() is the QByteArray's terminating NUL (0) byte. |
138 | * |
139 | * This allows for fast calculation of the bit array size: |
140 | * inline int size() const { return (d.size() << 3) - *d.constData(); } |
141 | */ |
142 | |
143 | /*! |
144 | Constructs a bit array containing \a size bits. The bits are |
145 | initialized with \a value, which defaults to false (0). |
146 | */ |
147 | QBitArray::QBitArray(int size, bool value) |
148 | : d(size <= 0 ? 0 : 1 + (size + 7)/8, Qt::Uninitialized) |
149 | { |
150 | Q_ASSERT_X(size >= 0, "QBitArray::QBitArray" , "Size must be greater than or equal to 0." ); |
151 | if (size <= 0) |
152 | return; |
153 | |
154 | uchar* c = reinterpret_cast<uchar*>(d.data()); |
155 | memset(s: c + 1, c: value ? 0xff : 0, n: d.size() - 1); |
156 | *c = d.size()*8 - size; |
157 | if (value && size && size & 7) |
158 | *(c+1+size/8) &= (1 << (size & 7)) - 1; |
159 | } |
160 | |
161 | /*! \fn int QBitArray::size() const |
162 | |
163 | Returns the number of bits stored in the bit array. |
164 | |
165 | \sa resize() |
166 | */ |
167 | |
168 | /*! \fn int QBitArray::count() const |
169 | |
170 | Same as size(). |
171 | */ |
172 | |
173 | /*! |
174 | If \a on is true, this function returns the number of |
175 | 1-bits stored in the bit array; otherwise the number |
176 | of 0-bits is returned. |
177 | */ |
178 | int QBitArray::count(bool on) const |
179 | { |
180 | int numBits = 0; |
181 | const quint8 *bits = reinterpret_cast<const quint8 *>(d.data()) + 1; |
182 | |
183 | // the loops below will try to read from *end |
184 | // it's the QByteArray implicit NUL, so it will not change the bit count |
185 | const quint8 *const end = reinterpret_cast<const quint8 *>(d.end()); |
186 | |
187 | while (bits + 7 <= end) { |
188 | quint64 v = qFromUnaligned<quint64>(src: bits); |
189 | bits += 8; |
190 | numBits += int(qPopulationCount(v)); |
191 | } |
192 | if (bits + 3 <= end) { |
193 | quint32 v = qFromUnaligned<quint32>(src: bits); |
194 | bits += 4; |
195 | numBits += int(qPopulationCount(v)); |
196 | } |
197 | if (bits + 1 < end) { |
198 | quint16 v = qFromUnaligned<quint16>(src: bits); |
199 | bits += 2; |
200 | numBits += int(qPopulationCount(v)); |
201 | } |
202 | if (bits < end) |
203 | numBits += int(qPopulationCount(v: bits[0])); |
204 | |
205 | return on ? numBits : size() - numBits; |
206 | } |
207 | |
208 | /*! |
209 | Resizes the bit array to \a size bits. |
210 | |
211 | If \a size is greater than the current size, the bit array is |
212 | extended to make it \a size bits with the extra bits added to the |
213 | end. The new bits are initialized to false (0). |
214 | |
215 | If \a size is less than the current size, bits are removed from |
216 | the end. |
217 | |
218 | \sa size() |
219 | */ |
220 | void QBitArray::resize(int size) |
221 | { |
222 | if (!size) { |
223 | d.resize(size: 0); |
224 | } else { |
225 | int s = d.size(); |
226 | d.resize(size: 1 + (size+7)/8); |
227 | uchar* c = reinterpret_cast<uchar*>(d.data()); |
228 | if (size > (s << 3)) |
229 | memset(s: c + s, c: 0, n: d.size() - s); |
230 | else if (size & 7) |
231 | *(c+1+size/8) &= (1 << (size & 7)) - 1; |
232 | *c = d.size()*8 - size; |
233 | } |
234 | } |
235 | |
236 | /*! \fn bool QBitArray::isEmpty() const |
237 | |
238 | Returns \c true if this bit array has size 0; otherwise returns |
239 | false. |
240 | |
241 | \sa size() |
242 | */ |
243 | |
244 | /*! \fn bool QBitArray::isNull() const |
245 | |
246 | Returns \c true if this bit array is null; otherwise returns \c false. |
247 | |
248 | Example: |
249 | \snippet code/src_corelib_tools_qbitarray.cpp 5 |
250 | |
251 | Qt makes a distinction between null bit arrays and empty bit |
252 | arrays for historical reasons. For most applications, what |
253 | matters is whether or not a bit array contains any data, |
254 | and this can be determined using isEmpty(). |
255 | |
256 | \sa isEmpty() |
257 | */ |
258 | |
259 | /*! \fn bool QBitArray::fill(bool value, int size = -1) |
260 | |
261 | Sets every bit in the bit array to \a value, returning true if successful; |
262 | otherwise returns \c false. If \a size is different from -1 (the default), |
263 | the bit array is resized to \a size beforehand. |
264 | |
265 | Example: |
266 | \snippet code/src_corelib_tools_qbitarray.cpp 6 |
267 | |
268 | \sa resize() |
269 | */ |
270 | |
271 | /*! |
272 | \overload |
273 | |
274 | Sets bits at index positions \a begin up to (but not including) \a end |
275 | to \a value. |
276 | |
277 | \a begin must be a valid index position in the bit array |
278 | (0 <= \a begin < size()). |
279 | |
280 | \a end must be either a valid index position or equal to size(), in |
281 | which case the fill operation runs until the end of the array |
282 | (0 <= \a end <= size()). |
283 | |
284 | Example: |
285 | \snippet code/src_corelib_tools_qbitarray.cpp 15 |
286 | */ |
287 | |
288 | void QBitArray::fill(bool value, int begin, int end) |
289 | { |
290 | while (begin < end && begin & 0x7) |
291 | setBit(i: begin++, val: value); |
292 | int len = end - begin; |
293 | if (len <= 0) |
294 | return; |
295 | int s = len & ~0x7; |
296 | uchar *c = reinterpret_cast<uchar*>(d.data()); |
297 | memset(s: c + (begin >> 3) + 1, c: value ? 0xff : 0, n: s >> 3); |
298 | begin += s; |
299 | while (begin < end) |
300 | setBit(i: begin++, val: value); |
301 | } |
302 | |
303 | /*! |
304 | \fn const char *QBitArray::bits() const |
305 | \since 5.11 |
306 | |
307 | Returns a pointer to a dense bit array for this QBitArray. Bits are counted |
308 | upwards from the least significant bit in each byte. The number of bits |
309 | relevant in the last byte is given by \c{size() % 8}. |
310 | |
311 | \sa fromBits(), size() |
312 | */ |
313 | |
314 | /*! |
315 | \since 5.11 |
316 | |
317 | Creates a QBitArray with the dense bit array located at \a data, with \a |
318 | size bits. The byte array at \a data must be at least \a size / 8 (rounded up) |
319 | bytes long. |
320 | |
321 | If \a size is not a multiple of 8, this function will include the lowest |
322 | \a size % 8 bits from the last byte in \a data. |
323 | |
324 | \sa bits() |
325 | */ |
326 | QBitArray QBitArray::fromBits(const char *data, qsizetype size) |
327 | { |
328 | QBitArray result; |
329 | if (size == 0) |
330 | return result; |
331 | qsizetype nbytes = (size + 7) / 8; |
332 | |
333 | result.d = QByteArray(nbytes + 1, Qt::Uninitialized); |
334 | char *bits = result.d.data(); |
335 | memcpy(dest: bits + 1, src: data, n: nbytes); |
336 | |
337 | // clear any unused bits from the last byte |
338 | if (size & 7) |
339 | bits[nbytes] &= 0xffU >> (8 - (size & 7)); |
340 | |
341 | *bits = result.d.size() * 8 - size; |
342 | return result; |
343 | } |
344 | |
345 | /*! \fn bool QBitArray::isDetached() const |
346 | |
347 | \internal |
348 | */ |
349 | |
350 | /*! \fn void QBitArray::detach() |
351 | |
352 | \internal |
353 | */ |
354 | |
355 | /*! \fn void QBitArray::clear() |
356 | |
357 | Clears the contents of the bit array and makes it empty. |
358 | |
359 | \sa resize(), isEmpty() |
360 | */ |
361 | |
362 | /*! \fn void QBitArray::truncate(int pos) |
363 | |
364 | Truncates the bit array at index position \a pos. |
365 | |
366 | If \a pos is beyond the end of the array, nothing happens. |
367 | |
368 | \sa resize() |
369 | */ |
370 | |
371 | /*! \fn bool QBitArray::toggleBit(int i) |
372 | |
373 | Inverts the value of the bit at index position \a i, returning the |
374 | previous value of that bit as either true (if it was set) or false (if |
375 | it was unset). |
376 | |
377 | If the previous value was 0, the new value will be 1. If the |
378 | previous value was 1, the new value will be 0. |
379 | |
380 | \a i must be a valid index position in the bit array (i.e., 0 <= |
381 | \a i < size()). |
382 | |
383 | \sa setBit(), clearBit() |
384 | */ |
385 | |
386 | /*! \fn bool QBitArray::testBit(int i) const |
387 | |
388 | Returns \c true if the bit at index position \a i is 1; otherwise |
389 | returns \c false. |
390 | |
391 | \a i must be a valid index position in the bit array (i.e., 0 <= |
392 | \a i < size()). |
393 | |
394 | \sa setBit(), clearBit() |
395 | */ |
396 | |
397 | /*! \fn bool QBitArray::setBit(int i) |
398 | |
399 | Sets the bit at index position \a i to 1. |
400 | |
401 | \a i must be a valid index position in the bit array (i.e., 0 <= |
402 | \a i < size()). |
403 | |
404 | \sa clearBit(), toggleBit() |
405 | */ |
406 | |
407 | /*! \fn void QBitArray::setBit(int i, bool value) |
408 | |
409 | \overload |
410 | |
411 | Sets the bit at index position \a i to \a value. |
412 | */ |
413 | |
414 | /*! \fn void QBitArray::clearBit(int i) |
415 | |
416 | Sets the bit at index position \a i to 0. |
417 | |
418 | \a i must be a valid index position in the bit array (i.e., 0 <= |
419 | \a i < size()). |
420 | |
421 | \sa setBit(), toggleBit() |
422 | */ |
423 | |
424 | /*! \fn bool QBitArray::at(int i) const |
425 | |
426 | Returns the value of the bit at index position \a i. |
427 | |
428 | \a i must be a valid index position in the bit array (i.e., 0 <= |
429 | \a i < size()). |
430 | |
431 | \sa operator[]() |
432 | */ |
433 | |
434 | /*! \fn QBitRef QBitArray::operator[](int i) |
435 | |
436 | Returns the bit at index position \a i as a modifiable reference. |
437 | |
438 | \a i must be a valid index position in the bit array (i.e., 0 <= |
439 | \a i < size()). |
440 | |
441 | Example: |
442 | \snippet code/src_corelib_tools_qbitarray.cpp 7 |
443 | |
444 | The return value is of type QBitRef, a helper class for QBitArray. |
445 | When you get an object of type QBitRef, you can assign to |
446 | it, and the assignment will apply to the bit in the QBitArray |
447 | from which you got the reference. |
448 | |
449 | The functions testBit(), setBit(), and clearBit() are slightly |
450 | faster. |
451 | |
452 | \sa at(), testBit(), setBit(), clearBit() |
453 | */ |
454 | |
455 | /*! \fn bool QBitArray::operator[](int i) const |
456 | |
457 | \overload |
458 | */ |
459 | |
460 | /*! \fn QBitRef QBitArray::operator[](uint i) |
461 | |
462 | \overload |
463 | */ |
464 | |
465 | /*! \fn bool QBitArray::operator[](uint i) const |
466 | |
467 | \overload |
468 | */ |
469 | |
470 | /*! \fn QBitArray::QBitArray(const QBitArray &other) |
471 | |
472 | Constructs a copy of \a other. |
473 | |
474 | This operation takes \l{constant time}, because QBitArray is |
475 | \l{implicitly shared}. This makes returning a QBitArray from a |
476 | function very fast. If a shared instance is modified, it will be |
477 | copied (copy-on-write), and that takes \l{linear time}. |
478 | |
479 | \sa operator=() |
480 | */ |
481 | |
482 | /*! \fn QBitArray &QBitArray::operator=(const QBitArray &other) |
483 | |
484 | Assigns \a other to this bit array and returns a reference to |
485 | this bit array. |
486 | */ |
487 | |
488 | /*! \fn QBitArray &QBitArray::operator=(QBitArray &&other) |
489 | \since 5.2 |
490 | |
491 | Moves \a other to this bit array and returns a reference to |
492 | this bit array. |
493 | */ |
494 | |
495 | /*! \fn void QBitArray::swap(QBitArray &other) |
496 | \since 4.8 |
497 | |
498 | Swaps bit array \a other with this bit array. This operation is very |
499 | fast and never fails. |
500 | */ |
501 | |
502 | /*! \fn bool QBitArray::operator==(const QBitArray &other) const |
503 | |
504 | Returns \c true if \a other is equal to this bit array; otherwise |
505 | returns \c false. |
506 | |
507 | \sa operator!=() |
508 | */ |
509 | |
510 | /*! \fn bool QBitArray::operator!=(const QBitArray &other) const |
511 | |
512 | Returns \c true if \a other is not equal to this bit array; |
513 | otherwise returns \c false. |
514 | |
515 | \sa operator==() |
516 | */ |
517 | |
518 | /*! |
519 | Performs the AND operation between all bits in this bit array and |
520 | \a other. Assigns the result to this bit array, and returns a |
521 | reference to it. |
522 | |
523 | The result has the length of the longest of the two bit arrays, |
524 | with any missing bits (if one array is shorter than the other) |
525 | taken to be 0. |
526 | |
527 | Example: |
528 | \snippet code/src_corelib_tools_qbitarray.cpp 8 |
529 | |
530 | \sa operator&(), operator|=(), operator^=(), operator~() |
531 | */ |
532 | |
533 | QBitArray &QBitArray::operator&=(const QBitArray &other) |
534 | { |
535 | resize(size: qMax(a: size(), b: other.size())); |
536 | uchar *a1 = reinterpret_cast<uchar*>(d.data()) + 1; |
537 | const uchar *a2 = reinterpret_cast<const uchar*>(other.d.constData()) + 1; |
538 | int n = other.d.size() -1 ; |
539 | int p = d.size() - 1 - n; |
540 | while (n-- > 0) |
541 | *a1++ &= *a2++; |
542 | while (p-- > 0) |
543 | *a1++ = 0; |
544 | return *this; |
545 | } |
546 | |
547 | /*! |
548 | Performs the OR operation between all bits in this bit array and |
549 | \a other. Assigns the result to this bit array, and returns a |
550 | reference to it. |
551 | |
552 | The result has the length of the longest of the two bit arrays, |
553 | with any missing bits (if one array is shorter than the other) |
554 | taken to be 0. |
555 | |
556 | Example: |
557 | \snippet code/src_corelib_tools_qbitarray.cpp 9 |
558 | |
559 | \sa operator|(), operator&=(), operator^=(), operator~() |
560 | */ |
561 | |
562 | QBitArray &QBitArray::operator|=(const QBitArray &other) |
563 | { |
564 | resize(size: qMax(a: size(), b: other.size())); |
565 | uchar *a1 = reinterpret_cast<uchar*>(d.data()) + 1; |
566 | const uchar *a2 = reinterpret_cast<const uchar *>(other.d.constData()) + 1; |
567 | int n = other.d.size() - 1; |
568 | while (n-- > 0) |
569 | *a1++ |= *a2++; |
570 | return *this; |
571 | } |
572 | |
573 | /*! |
574 | Performs the XOR operation between all bits in this bit array and |
575 | \a other. Assigns the result to this bit array, and returns a |
576 | reference to it. |
577 | |
578 | The result has the length of the longest of the two bit arrays, |
579 | with any missing bits (if one array is shorter than the other) |
580 | taken to be 0. |
581 | |
582 | Example: |
583 | \snippet code/src_corelib_tools_qbitarray.cpp 10 |
584 | |
585 | \sa operator^(), operator&=(), operator|=(), operator~() |
586 | */ |
587 | |
588 | QBitArray &QBitArray::operator^=(const QBitArray &other) |
589 | { |
590 | resize(size: qMax(a: size(), b: other.size())); |
591 | uchar *a1 = reinterpret_cast<uchar*>(d.data()) + 1; |
592 | const uchar *a2 = reinterpret_cast<const uchar *>(other.d.constData()) + 1; |
593 | int n = other.d.size() - 1; |
594 | while (n-- > 0) |
595 | *a1++ ^= *a2++; |
596 | return *this; |
597 | } |
598 | |
599 | /*! |
600 | Returns a bit array that contains the inverted bits of this bit |
601 | array. |
602 | |
603 | Example: |
604 | \snippet code/src_corelib_tools_qbitarray.cpp 11 |
605 | |
606 | \sa operator&(), operator|(), operator^() |
607 | */ |
608 | |
609 | QBitArray QBitArray::operator~() const |
610 | { |
611 | int sz = size(); |
612 | QBitArray a(sz); |
613 | const uchar *a1 = reinterpret_cast<const uchar *>(d.constData()) + 1; |
614 | uchar *a2 = reinterpret_cast<uchar*>(a.d.data()) + 1; |
615 | int n = d.size() - 1; |
616 | |
617 | while (n-- > 0) |
618 | *a2++ = ~*a1++; |
619 | |
620 | if (sz && sz%8) |
621 | *(a2-1) &= (1 << (sz%8)) - 1; |
622 | return a; |
623 | } |
624 | |
625 | /*! |
626 | \relates QBitArray |
627 | |
628 | Returns a bit array that is the AND of the bit arrays \a a1 and \a |
629 | a2. |
630 | |
631 | The result has the length of the longest of the two bit arrays, |
632 | with any missing bits (if one array is shorter than the other) |
633 | taken to be 0. |
634 | |
635 | Example: |
636 | \snippet code/src_corelib_tools_qbitarray.cpp 12 |
637 | |
638 | \sa {QBitArray::}{operator&=()}, {QBitArray::}{operator|()}, {QBitArray::}{operator^()} |
639 | */ |
640 | |
641 | QBitArray operator&(const QBitArray &a1, const QBitArray &a2) |
642 | { |
643 | QBitArray tmp = a1; |
644 | tmp &= a2; |
645 | return tmp; |
646 | } |
647 | |
648 | /*! |
649 | \relates QBitArray |
650 | |
651 | Returns a bit array that is the OR of the bit arrays \a a1 and \a |
652 | a2. |
653 | |
654 | The result has the length of the longest of the two bit arrays, |
655 | with any missing bits (if one array is shorter than the other) |
656 | taken to be 0. |
657 | |
658 | Example: |
659 | \snippet code/src_corelib_tools_qbitarray.cpp 13 |
660 | |
661 | \sa QBitArray::operator|=(), operator&(), operator^() |
662 | */ |
663 | |
664 | QBitArray operator|(const QBitArray &a1, const QBitArray &a2) |
665 | { |
666 | QBitArray tmp = a1; |
667 | tmp |= a2; |
668 | return tmp; |
669 | } |
670 | |
671 | /*! |
672 | \relates QBitArray |
673 | |
674 | Returns a bit array that is the XOR of the bit arrays \a a1 and \a |
675 | a2. |
676 | |
677 | The result has the length of the longest of the two bit arrays, |
678 | with any missing bits (if one array is shorter than the other) |
679 | taken to be 0. |
680 | |
681 | Example: |
682 | \snippet code/src_corelib_tools_qbitarray.cpp 14 |
683 | |
684 | \sa {QBitArray}{operator^=()}, {QBitArray}{operator&()}, {QBitArray}{operator|()} |
685 | */ |
686 | |
687 | QBitArray operator^(const QBitArray &a1, const QBitArray &a2) |
688 | { |
689 | QBitArray tmp = a1; |
690 | tmp ^= a2; |
691 | return tmp; |
692 | } |
693 | |
694 | /*! |
695 | \class QBitRef |
696 | \inmodule QtCore |
697 | \reentrant |
698 | \brief The QBitRef class is an internal class, used with QBitArray. |
699 | |
700 | \internal |
701 | |
702 | The QBitRef is required by the indexing [] operator on bit arrays. |
703 | It is not for use in any other context. |
704 | */ |
705 | |
706 | /*! \fn QBitRef::QBitRef (QBitArray& a, int i) |
707 | |
708 | Constructs a reference to element \a i in the QBitArray \a a. |
709 | This is what QBitArray::operator[] constructs its return value |
710 | with. |
711 | */ |
712 | |
713 | /*! \fn QBitRef::operator bool() const |
714 | |
715 | Returns the value referenced by the QBitRef. |
716 | */ |
717 | |
718 | /*! \fn bool QBitRef::operator!() const |
719 | |
720 | \internal |
721 | */ |
722 | |
723 | /*! \fn QBitRef& QBitRef::operator= (const QBitRef& v) |
724 | |
725 | Sets the value referenced by the QBitRef to that referenced by |
726 | QBitRef \a v. |
727 | */ |
728 | |
729 | /*! \fn QBitRef& QBitRef::operator= (bool v) |
730 | \overload |
731 | |
732 | Sets the value referenced by the QBitRef to \a v. |
733 | */ |
734 | |
735 | |
736 | /***************************************************************************** |
737 | QBitArray stream functions |
738 | *****************************************************************************/ |
739 | |
740 | #ifndef QT_NO_DATASTREAM |
741 | /*! |
742 | \relates QBitArray |
743 | |
744 | Writes bit array \a ba to stream \a out. |
745 | |
746 | \sa {Serializing Qt Data Types}{Format of the QDataStream operators} |
747 | */ |
748 | |
749 | QDataStream &operator<<(QDataStream &out, const QBitArray &ba) |
750 | { |
751 | quint32 len = ba.size(); |
752 | out << len; |
753 | if (len > 0) |
754 | out.writeRawData(ba.d.constData() + 1, len: ba.d.size() - 1); |
755 | return out; |
756 | } |
757 | |
758 | /*! |
759 | \relates QBitArray |
760 | |
761 | Reads a bit array into \a ba from stream \a in. |
762 | |
763 | \sa {Serializing Qt Data Types}{Format of the QDataStream operators} |
764 | */ |
765 | |
766 | QDataStream &operator>>(QDataStream &in, QBitArray &ba) |
767 | { |
768 | ba.clear(); |
769 | quint32 len; |
770 | in >> len; |
771 | if (len == 0) { |
772 | ba.clear(); |
773 | return in; |
774 | } |
775 | |
776 | const quint32 Step = 8 * 1024 * 1024; |
777 | quint32 totalBytes = (len + 7) / 8; |
778 | quint32 allocated = 0; |
779 | |
780 | while (allocated < totalBytes) { |
781 | int blockSize = qMin(a: Step, b: totalBytes - allocated); |
782 | ba.d.resize(size: allocated + blockSize + 1); |
783 | if (in.readRawData(ba.d.data() + 1 + allocated, len: blockSize) != blockSize) { |
784 | ba.clear(); |
785 | in.setStatus(QDataStream::ReadPastEnd); |
786 | return in; |
787 | } |
788 | allocated += blockSize; |
789 | } |
790 | |
791 | int paddingMask = ~((0x1 << (len & 0x7)) - 1); |
792 | if (paddingMask != ~0x0 && (ba.d.constData()[ba.d.size() - 1] & paddingMask)) { |
793 | ba.clear(); |
794 | in.setStatus(QDataStream::ReadCorruptData); |
795 | return in; |
796 | } |
797 | |
798 | *ba.d.data() = ba.d.size() * 8 - len; |
799 | return in; |
800 | } |
801 | #endif // QT_NO_DATASTREAM |
802 | |
803 | #ifndef QT_NO_DEBUG_STREAM |
804 | QDebug operator<<(QDebug dbg, const QBitArray &array) |
805 | { |
806 | QDebugStateSaver saver(dbg); |
807 | dbg.nospace() << "QBitArray(" ; |
808 | for (int i = 0; i < array.size();) { |
809 | if (array.testBit(i)) |
810 | dbg << '1'; |
811 | else |
812 | dbg << '0'; |
813 | i += 1; |
814 | if (!(i % 4) && (i < array.size())) |
815 | dbg << ' '; |
816 | } |
817 | dbg << ')'; |
818 | return dbg; |
819 | } |
820 | #endif |
821 | |
822 | /*! |
823 | \fn DataPtr &QBitArray::data_ptr() |
824 | \internal |
825 | */ |
826 | |
827 | /*! |
828 | \typedef QBitArray::DataPtr |
829 | \internal |
830 | */ |
831 | |
832 | QT_END_NAMESPACE |
833 | |