xpcom/string/src/nsReadableUtils.cpp@6474c204b198
xpcom/string/src/nsReadableUtils.cpp
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6 #include "nsReadableUtils.h"
8 #include "nsMemory.h"
9 #include "nsString.h"
10 #include "nsTArray.h"
11 #include "nsUTF8Utils.h"
13 void
14 LossyCopyUTF16toASCII( const nsAString& aSource, nsACString& aDest )
15 {
16 aDest.Truncate();
17 LossyAppendUTF16toASCII(aSource, aDest);
18 }
20 void
21 CopyASCIItoUTF16( const nsACString& aSource, nsAString& aDest )
22 {
23 aDest.Truncate();
24 AppendASCIItoUTF16(aSource, aDest);
25 }
27 void
28 LossyCopyUTF16toASCII( const char16_t* aSource, nsACString& aDest )
29 {
30 aDest.Truncate();
31 if (aSource) {
32 LossyAppendUTF16toASCII(nsDependentString(aSource), aDest);
33 }
34 }
36 void
37 CopyASCIItoUTF16( const char* aSource, nsAString& aDest )
38 {
39 aDest.Truncate();
40 if (aSource) {
41 AppendASCIItoUTF16(nsDependentCString(aSource), aDest);
42 }
43 }
45 void
46 CopyUTF16toUTF8( const nsAString& aSource, nsACString& aDest )
47 {
48 aDest.Truncate();
49 AppendUTF16toUTF8(aSource, aDest);
50 }
52 void
53 CopyUTF8toUTF16( const nsACString& aSource, nsAString& aDest )
54 {
55 aDest.Truncate();
56 AppendUTF8toUTF16(aSource, aDest);
57 }
59 void
60 CopyUTF16toUTF8( const char16_t* aSource, nsACString& aDest )
61 {
62 aDest.Truncate();
63 AppendUTF16toUTF8(aSource, aDest);
64 }
66 void
67 CopyUTF8toUTF16( const char* aSource, nsAString& aDest )
68 {
69 aDest.Truncate();
70 AppendUTF8toUTF16(aSource, aDest);
71 }
73 void
74 LossyAppendUTF16toASCII( const nsAString& aSource, nsACString& aDest )
75 {
76 uint32_t old_dest_length = aDest.Length();
77 aDest.SetLength(old_dest_length + aSource.Length());
79 nsAString::const_iterator fromBegin, fromEnd;
81 nsACString::iterator dest;
82 aDest.BeginWriting(dest);
84 dest.advance(old_dest_length);
86 // right now, this won't work on multi-fragment destinations
87 LossyConvertEncoding16to8 converter(dest.get());
89 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter);
90 }
92 void
93 AppendASCIItoUTF16( const nsACString& aSource, nsAString& aDest )
94 {
95 if (!AppendASCIItoUTF16(aSource, aDest, mozilla::fallible_t())) {
96 NS_ABORT_OOM(aDest.Length() + aSource.Length());
97 }
98 }
100 bool
101 AppendASCIItoUTF16( const nsACString& aSource, nsAString& aDest,
102 const mozilla::fallible_t& )
103 {
104 uint32_t old_dest_length = aDest.Length();
105 if (!aDest.SetLength(old_dest_length + aSource.Length(), mozilla::fallible_t())) {
106 return false;
107 }
109 nsACString::const_iterator fromBegin, fromEnd;
111 nsAString::iterator dest;
112 aDest.BeginWriting(dest);
114 dest.advance(old_dest_length);
116 // right now, this won't work on multi-fragment destinations
117 LossyConvertEncoding8to16 converter(dest.get());
119 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter);
120 return true;
121 }
123 void
124 LossyAppendUTF16toASCII( const char16_t* aSource, nsACString& aDest )
125 {
126 if (aSource) {
127 LossyAppendUTF16toASCII(nsDependentString(aSource), aDest);
128 }
129 }
131 void
132 AppendASCIItoUTF16( const char* aSource, nsAString& aDest )
133 {
134 if (aSource) {
135 AppendASCIItoUTF16(nsDependentCString(aSource), aDest);
136 }
137 }
139 void
140 AppendUTF16toUTF8( const nsAString& aSource, nsACString& aDest )
141 {
142 if (!AppendUTF16toUTF8(aSource, aDest, mozilla::fallible_t())) {
143 NS_ABORT_OOM(aDest.Length() + aSource.Length());
144 }
145 }
147 bool
148 AppendUTF16toUTF8( const nsAString& aSource, nsACString& aDest,
149 const mozilla::fallible_t& )
150 {
151 nsAString::const_iterator source_start, source_end;
152 CalculateUTF8Size calculator;
153 copy_string(aSource.BeginReading(source_start),
154 aSource.EndReading(source_end), calculator);
156 uint32_t count = calculator.Size();
158 if (count)
159 {
160 uint32_t old_dest_length = aDest.Length();
162 // Grow the buffer if we need to.
163 if (!aDest.SetLength(old_dest_length + count, mozilla::fallible_t())) {
164 return false;
165 }
167 // All ready? Time to convert
169 ConvertUTF16toUTF8 converter(aDest.BeginWriting() + old_dest_length);
170 copy_string(aSource.BeginReading(source_start),
171 aSource.EndReading(source_end), converter);
173 NS_ASSERTION(converter.Size() == count,
174 "Unexpected disparity between CalculateUTF8Size and "
175 "ConvertUTF16toUTF8");
176 }
178 return true;
179 }
181 void
182 AppendUTF8toUTF16( const nsACString& aSource, nsAString& aDest )
183 {
184 if (!AppendUTF8toUTF16(aSource, aDest, mozilla::fallible_t())) {
185 NS_ABORT_OOM(aDest.Length() + aSource.Length());
186 }
187 }
189 bool
190 AppendUTF8toUTF16( const nsACString& aSource, nsAString& aDest,
191 const mozilla::fallible_t& )
192 {
193 nsACString::const_iterator source_start, source_end;
194 CalculateUTF8Length calculator;
195 copy_string(aSource.BeginReading(source_start),
196 aSource.EndReading(source_end), calculator);
198 uint32_t count = calculator.Length();
200 // Avoid making the string mutable if we're appending an empty string
201 if (count)
202 {
203 uint32_t old_dest_length = aDest.Length();
205 // Grow the buffer if we need to.
206 if (!aDest.SetLength(old_dest_length + count, mozilla::fallible_t())) {
207 return false;
208 }
210 // All ready? Time to convert
212 ConvertUTF8toUTF16 converter(aDest.BeginWriting() + old_dest_length);
213 copy_string(aSource.BeginReading(source_start),
214 aSource.EndReading(source_end), converter);
216 NS_ASSERTION(converter.ErrorEncountered() ||
217 converter.Length() == count,
218 "CalculateUTF8Length produced the wrong length");
220 if (converter.ErrorEncountered())
221 {
222 NS_ERROR("Input wasn't UTF8 or incorrect length was calculated");
223 aDest.SetLength(old_dest_length);
224 }
225 }
227 return true;
228 }
230 void
231 AppendUTF16toUTF8( const char16_t* aSource, nsACString& aDest )
232 {
233 if (aSource) {
234 AppendUTF16toUTF8(nsDependentString(aSource), aDest);
235 }
236 }
238 void
239 AppendUTF8toUTF16( const char* aSource, nsAString& aDest )
240 {
241 if (aSource) {
242 AppendUTF8toUTF16(nsDependentCString(aSource), aDest);
243 }
244 }
247 /**
248 * A helper function that allocates a buffer of the desired character type big enough to hold a copy of the supplied string (plus a zero terminator).
249 *
250 * @param aSource an string you will eventually be making a copy of
251 * @return a new buffer (of the type specified by the second parameter) which you must free with |nsMemory::Free|.
252 *
253 */
254 template <class FromStringT, class ToCharT>
255 inline
256 ToCharT*
257 AllocateStringCopy( const FromStringT& aSource, ToCharT* )
258 {
259 return static_cast<ToCharT*>(nsMemory::Alloc((aSource.Length()+1) * sizeof(ToCharT)));
260 }
263 char*
264 ToNewCString( const nsAString& aSource )
265 {
266 char* result = AllocateStringCopy(aSource, (char*)0);
267 if (!result)
268 return nullptr;
270 nsAString::const_iterator fromBegin, fromEnd;
271 LossyConvertEncoding16to8 converter(result);
272 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter).write_terminator();
273 return result;
274 }
276 char*
277 ToNewUTF8String( const nsAString& aSource, uint32_t *aUTF8Count )
278 {
279 nsAString::const_iterator start, end;
280 CalculateUTF8Size calculator;
281 copy_string(aSource.BeginReading(start), aSource.EndReading(end),
282 calculator);
284 if (aUTF8Count)
285 *aUTF8Count = calculator.Size();
287 char *result = static_cast<char*>
288 (nsMemory::Alloc(calculator.Size() + 1));
289 if (!result)
290 return nullptr;
292 ConvertUTF16toUTF8 converter(result);
293 copy_string(aSource.BeginReading(start), aSource.EndReading(end),
294 converter).write_terminator();
295 NS_ASSERTION(calculator.Size() == converter.Size(), "length mismatch");
297 return result;
298 }
300 char*
301 ToNewCString( const nsACString& aSource )
302 {
303 // no conversion needed, just allocate a buffer of the correct length and copy into it
305 char* result = AllocateStringCopy(aSource, (char*)0);
306 if (!result)
307 return nullptr;
309 nsACString::const_iterator fromBegin, fromEnd;
310 char* toBegin = result;
311 *copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), toBegin) = char(0);
312 return result;
313 }
315 char16_t*
316 ToNewUnicode( const nsAString& aSource )
317 {
318 // no conversion needed, just allocate a buffer of the correct length and copy into it
320 char16_t* result = AllocateStringCopy(aSource, (char16_t*)0);
321 if (!result)
322 return nullptr;
324 nsAString::const_iterator fromBegin, fromEnd;
325 char16_t* toBegin = result;
326 *copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), toBegin) = char16_t(0);
327 return result;
328 }
330 char16_t*
331 ToNewUnicode( const nsACString& aSource )
332 {
333 char16_t* result = AllocateStringCopy(aSource, (char16_t*)0);
334 if (!result)
335 return nullptr;
337 nsACString::const_iterator fromBegin, fromEnd;
338 LossyConvertEncoding8to16 converter(result);
339 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter).write_terminator();
340 return result;
341 }
343 uint32_t
344 CalcUTF8ToUnicodeLength( const nsACString& aSource)
345 {
346 nsACString::const_iterator start, end;
347 CalculateUTF8Length calculator;
348 copy_string(aSource.BeginReading(start), aSource.EndReading(end),
349 calculator);
350 return calculator.Length();
351 }
353 char16_t*
354 UTF8ToUnicodeBuffer( const nsACString& aSource, char16_t* aBuffer, uint32_t *aUTF16Count )
355 {
356 nsACString::const_iterator start, end;
357 ConvertUTF8toUTF16 converter(aBuffer);
358 copy_string(aSource.BeginReading(start),
359 aSource.EndReading(end),
360 converter).write_terminator();
361 if (aUTF16Count)
362 *aUTF16Count = converter.Length();
363 return aBuffer;
364 }
366 char16_t*
367 UTF8ToNewUnicode( const nsACString& aSource, uint32_t *aUTF16Count )
368 {
369 const uint32_t length = CalcUTF8ToUnicodeLength(aSource);
370 const size_t buffer_size = (length + 1) * sizeof(char16_t);
371 char16_t *buffer = static_cast<char16_t*>(nsMemory::Alloc(buffer_size));
372 if (!buffer)
373 return nullptr;
375 uint32_t copied;
376 UTF8ToUnicodeBuffer(aSource, buffer, &copied);
377 NS_ASSERTION(length == copied, "length mismatch");
379 if (aUTF16Count)
380 *aUTF16Count = copied;
381 return buffer;
382 }
384 char16_t*
385 CopyUnicodeTo( const nsAString& aSource, uint32_t aSrcOffset, char16_t* aDest, uint32_t aLength )
386 {
387 nsAString::const_iterator fromBegin, fromEnd;
388 char16_t* toBegin = aDest;
389 copy_string(aSource.BeginReading(fromBegin).advance( int32_t(aSrcOffset) ), aSource.BeginReading(fromEnd).advance( int32_t(aSrcOffset+aLength) ), toBegin);
390 return aDest;
391 }
393 void
394 CopyUnicodeTo( const nsAString::const_iterator& aSrcStart,
395 const nsAString::const_iterator& aSrcEnd,
396 nsAString& aDest )
397 {
398 nsAString::iterator writer;
399 aDest.SetLength(Distance(aSrcStart, aSrcEnd));
401 aDest.BeginWriting(writer);
402 nsAString::const_iterator fromBegin(aSrcStart);
404 copy_string(fromBegin, aSrcEnd, writer);
405 }
407 void
408 AppendUnicodeTo( const nsAString::const_iterator& aSrcStart,
409 const nsAString::const_iterator& aSrcEnd,
410 nsAString& aDest )
411 {
412 nsAString::iterator writer;
413 uint32_t oldLength = aDest.Length();
414 aDest.SetLength(oldLength + Distance(aSrcStart, aSrcEnd));
416 aDest.BeginWriting(writer).advance(oldLength);
417 nsAString::const_iterator fromBegin(aSrcStart);
419 copy_string(fromBegin, aSrcEnd, writer);
420 }
422 bool
423 IsASCII( const nsAString& aString )
424 {
425 static const char16_t NOT_ASCII = char16_t(~0x007F);
428 // Don't want to use |copy_string| for this task, since we can stop at the first non-ASCII character
430 nsAString::const_iterator iter, done_reading;
431 aString.BeginReading(iter);
432 aString.EndReading(done_reading);
434 const char16_t* c = iter.get();
435 const char16_t* end = done_reading.get();
437 while ( c < end )
438 {
439 if ( *c++ & NOT_ASCII )
440 return false;
441 }
443 return true;
444 }
446 bool
447 IsASCII( const nsACString& aString )
448 {
449 static const char NOT_ASCII = char(~0x7F);
452 // Don't want to use |copy_string| for this task, since we can stop at the first non-ASCII character
454 nsACString::const_iterator iter, done_reading;
455 aString.BeginReading(iter);
456 aString.EndReading(done_reading);
458 const char* c = iter.get();
459 const char* end = done_reading.get();
461 while ( c < end )
462 {
463 if ( *c++ & NOT_ASCII )
464 return false;
465 }
467 return true;
468 }
470 bool
471 IsUTF8( const nsACString& aString, bool aRejectNonChar )
472 {
473 nsReadingIterator<char> done_reading;
474 aString.EndReading(done_reading);
476 int32_t state = 0;
477 bool overlong = false;
478 bool surrogate = false;
479 bool nonchar = false;
480 uint16_t olupper = 0; // overlong byte upper bound.
481 uint16_t slower = 0; // surrogate byte lower bound.
483 nsReadingIterator<char> iter;
484 aString.BeginReading(iter);
486 const char* ptr = iter.get();
487 const char* end = done_reading.get();
488 while ( ptr < end )
489 {
490 uint8_t c;
492 if (0 == state)
493 {
494 c = *ptr++;
496 if ( UTF8traits::isASCII(c) )
497 continue;
499 if ( c <= 0xC1 ) // [80-BF] where not expected, [C0-C1] for overlong.
500 return false;
501 else if ( UTF8traits::is2byte(c) )
502 state = 1;
503 else if ( UTF8traits::is3byte(c) )
504 {
505 state = 2;
506 if ( c == 0xE0 ) // to exclude E0[80-9F][80-BF]
507 {
508 overlong = true;
509 olupper = 0x9F;
510 }
511 else if ( c == 0xED ) // ED[A0-BF][80-BF] : surrogate codepoint
512 {
513 surrogate = true;
514 slower = 0xA0;
515 }
516 else if ( c == 0xEF ) // EF BF [BE-BF] : non-character
517 nonchar = true;
518 }
519 else if ( c <= 0xF4 ) // XXX replace /w UTF8traits::is4byte when it's updated to exclude [F5-F7].(bug 199090)
520 {
521 state = 3;
522 nonchar = true;
523 if ( c == 0xF0 ) // to exclude F0[80-8F][80-BF]{2}
524 {
525 overlong = true;
526 olupper = 0x8F;
527 }
528 else if ( c == 0xF4 ) // to exclude F4[90-BF][80-BF]
529 {
530 // actually not surrogates but codepoints beyond 0x10FFFF
531 surrogate = true;
532 slower = 0x90;
533 }
534 }
535 else
536 return false; // Not UTF-8 string
537 }
539 if (nonchar && !aRejectNonChar)
540 nonchar = false;
542 while ( ptr < end && state )
543 {
544 c = *ptr++;
545 --state;
547 // non-character : EF BF [BE-BF] or F[0-7] [89AB]F BF [BE-BF]
548 if ( nonchar &&
549 ( ( !state && c < 0xBE ) ||
550 ( state == 1 && c != 0xBF ) ||
551 ( state == 2 && 0x0F != (0x0F & c) )))
552 nonchar = false;
554 if ( !UTF8traits::isInSeq(c) || ( overlong && c <= olupper ) ||
555 ( surrogate && slower <= c ) || ( nonchar && !state ))
556 return false; // Not UTF-8 string
558 overlong = surrogate = false;
559 }
560 }
561 return !state; // state != 0 at the end indicates an invalid UTF-8 seq.
562 }
564 /**
565 * A character sink for in-place case conversion.
566 */
567 class ConvertToUpperCase
568 {
569 public:
570 typedef char value_type;
572 uint32_t
573 write( const char* aSource, uint32_t aSourceLength )
574 {
575 char* cp = const_cast<char*>(aSource);
576 const char* end = aSource + aSourceLength;
577 while (cp != end) {
578 char ch = *cp;
579 if ((ch >= 'a') && (ch <= 'z'))
580 *cp = ch - ('a' - 'A');
581 ++cp;
582 }
583 return aSourceLength;
584 }
585 };
587 void
588 ToUpperCase( nsCSubstring& aCString )
589 {
590 ConvertToUpperCase converter;
591 char* start;
592 converter.write(aCString.BeginWriting(start), aCString.Length());
593 }
595 /**
596 * A character sink for copying with case conversion.
597 */
598 class CopyToUpperCase
599 {
600 public:
601 typedef char value_type;
603 CopyToUpperCase( nsACString::iterator& aDestIter )
604 : mIter(aDestIter)
605 {
606 }
608 uint32_t
609 write( const char* aSource, uint32_t aSourceLength )
610 {
611 uint32_t len = XPCOM_MIN(uint32_t(mIter.size_forward()), aSourceLength);
612 char* cp = mIter.get();
613 const char* end = aSource + len;
614 while (aSource != end) {
615 char ch = *aSource;
616 if ((ch >= 'a') && (ch <= 'z'))
617 *cp = ch - ('a' - 'A');
618 else
619 *cp = ch;
620 ++aSource;
621 ++cp;
622 }
623 mIter.advance(len);
624 return len;
625 }
627 protected:
628 nsACString::iterator& mIter;
629 };
631 void
632 ToUpperCase( const nsACString& aSource, nsACString& aDest )
633 {
634 nsACString::const_iterator fromBegin, fromEnd;
635 nsACString::iterator toBegin;
636 aDest.SetLength(aSource.Length());
638 CopyToUpperCase converter(aDest.BeginWriting(toBegin));
639 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter);
640 }
642 /**
643 * A character sink for case conversion.
644 */
645 class ConvertToLowerCase
646 {
647 public:
648 typedef char value_type;
650 uint32_t
651 write( const char* aSource, uint32_t aSourceLength )
652 {
653 char* cp = const_cast<char*>(aSource);
654 const char* end = aSource + aSourceLength;
655 while (cp != end) {
656 char ch = *cp;
657 if ((ch >= 'A') && (ch <= 'Z'))
658 *cp = ch + ('a' - 'A');
659 ++cp;
660 }
661 return aSourceLength;
662 }
663 };
665 void
666 ToLowerCase( nsCSubstring& aCString )
667 {
668 ConvertToLowerCase converter;
669 char* start;
670 converter.write(aCString.BeginWriting(start), aCString.Length());
671 }
673 /**
674 * A character sink for copying with case conversion.
675 */
676 class CopyToLowerCase
677 {
678 public:
679 typedef char value_type;
681 CopyToLowerCase( nsACString::iterator& aDestIter )
682 : mIter(aDestIter)
683 {
684 }
686 uint32_t
687 write( const char* aSource, uint32_t aSourceLength )
688 {
689 uint32_t len = XPCOM_MIN(uint32_t(mIter.size_forward()), aSourceLength);
690 char* cp = mIter.get();
691 const char* end = aSource + len;
692 while (aSource != end) {
693 char ch = *aSource;
694 if ((ch >= 'A') && (ch <= 'Z'))
695 *cp = ch + ('a' - 'A');
696 else
697 *cp = ch;
698 ++aSource;
699 ++cp;
700 }
701 mIter.advance(len);
702 return len;
703 }
705 protected:
706 nsACString::iterator& mIter;
707 };
709 void
710 ToLowerCase( const nsACString& aSource, nsACString& aDest )
711 {
712 nsACString::const_iterator fromBegin, fromEnd;
713 nsACString::iterator toBegin;
714 aDest.SetLength(aSource.Length());
716 CopyToLowerCase converter(aDest.BeginWriting(toBegin));
717 copy_string(aSource.BeginReading(fromBegin), aSource.EndReading(fromEnd), converter);
718 }
720 bool
721 ParseString(const nsACString& aSource, char aDelimiter,
722 nsTArray<nsCString>& aArray)
723 {
724 nsACString::const_iterator start, end;
725 aSource.BeginReading(start);
726 aSource.EndReading(end);
728 uint32_t oldLength = aArray.Length();
730 for (;;)
731 {
732 nsACString::const_iterator delimiter = start;
733 FindCharInReadable(aDelimiter, delimiter, end);
735 if (delimiter != start)
736 {
737 if (!aArray.AppendElement(Substring(start, delimiter)))
738 {
739 aArray.RemoveElementsAt(oldLength, aArray.Length() - oldLength);
740 return false;
741 }
742 }
744 if (delimiter == end)
745 break;
746 start = ++delimiter;
747 if (start == end)
748 break;
749 }
751 return true;
752 }
754 template <class StringT, class IteratorT, class Comparator>
755 bool
756 FindInReadable_Impl( const StringT& aPattern, IteratorT& aSearchStart, IteratorT& aSearchEnd, const Comparator& compare )
757 {
758 bool found_it = false;
760 // only bother searching at all if we're given a non-empty range to search
761 if ( aSearchStart != aSearchEnd )
762 {
763 IteratorT aPatternStart, aPatternEnd;
764 aPattern.BeginReading(aPatternStart);
765 aPattern.EndReading(aPatternEnd);
767 // outer loop keeps searching till we find it or run out of string to search
768 while ( !found_it )
769 {
770 // fast inner loop (that's what it's called, not what it is) looks for a potential match
771 while ( aSearchStart != aSearchEnd &&
772 compare(aPatternStart.get(), aSearchStart.get(), 1, 1) )
773 ++aSearchStart;
775 // if we broke out of the `fast' loop because we're out of string ... we're done: no match
776 if ( aSearchStart == aSearchEnd )
777 break;
779 // otherwise, we're at a potential match, let's see if we really hit one
780 IteratorT testPattern(aPatternStart);
781 IteratorT testSearch(aSearchStart);
783 // slow inner loop verifies the potential match (found by the `fast' loop) at the current position
784 for(;;)
785 {
786 // we already compared the first character in the outer loop,
787 // so we'll advance before the next comparison
788 ++testPattern;
789 ++testSearch;
791 // if we verified all the way to the end of the pattern, then we found it!
792 if ( testPattern == aPatternEnd )
793 {
794 found_it = true;
795 aSearchEnd = testSearch; // return the exact found range through the parameters
796 break;
797 }
799 // if we got to end of the string we're searching before we hit the end of the
800 // pattern, we'll never find what we're looking for
801 if ( testSearch == aSearchEnd )
802 {
803 aSearchStart = aSearchEnd;
804 break;
805 }
807 // else if we mismatched ... it's time to advance to the next search position
808 // and get back into the `fast' loop
809 if ( compare(testPattern.get(), testSearch.get(), 1, 1) )
810 {
811 ++aSearchStart;
812 break;
813 }
814 }
815 }
816 }
818 return found_it;
819 }
821 /**
822 * This searches the entire string from right to left, and returns the first match found, if any.
823 */
824 template <class StringT, class IteratorT, class Comparator>
825 bool
826 RFindInReadable_Impl( const StringT& aPattern, IteratorT& aSearchStart, IteratorT& aSearchEnd, const Comparator& compare )
827 {
828 IteratorT patternStart, patternEnd, searchEnd = aSearchEnd;
829 aPattern.BeginReading(patternStart);
830 aPattern.EndReading(patternEnd);
832 // Point to the last character in the pattern
833 --patternEnd;
834 // outer loop keeps searching till we run out of string to search
835 while ( aSearchStart != searchEnd )
836 {
837 // Point to the end position of the next possible match
838 --searchEnd;
840 // Check last character, if a match, explore further from here
841 if ( compare(patternEnd.get(), searchEnd.get(), 1, 1) == 0 )
842 {
843 // We're at a potential match, let's see if we really hit one
844 IteratorT testPattern(patternEnd);
845 IteratorT testSearch(searchEnd);
847 // inner loop verifies the potential match at the current position
848 do
849 {
850 // if we verified all the way to the end of the pattern, then we found it!
851 if ( testPattern == patternStart )
852 {
853 aSearchStart = testSearch; // point to start of match
854 aSearchEnd = ++searchEnd; // point to end of match
855 return true;
856 }
858 // if we got to end of the string we're searching before we hit the end of the
859 // pattern, we'll never find what we're looking for
860 if ( testSearch == aSearchStart )
861 {
862 aSearchStart = aSearchEnd;
863 return false;
864 }
866 // test previous character for a match
867 --testPattern;
868 --testSearch;
869 }
870 while ( compare(testPattern.get(), testSearch.get(), 1, 1) == 0 );
871 }
872 }
874 aSearchStart = aSearchEnd;
875 return false;
876 }
878 bool
879 FindInReadable( const nsAString& aPattern, nsAString::const_iterator& aSearchStart, nsAString::const_iterator& aSearchEnd, const nsStringComparator& aComparator )
880 {
881 return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
882 }
884 bool
885 FindInReadable( const nsACString& aPattern, nsACString::const_iterator& aSearchStart, nsACString::const_iterator& aSearchEnd, const nsCStringComparator& aComparator)
886 {
887 return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
888 }
890 bool
891 CaseInsensitiveFindInReadable( const nsACString& aPattern, nsACString::const_iterator& aSearchStart, nsACString::const_iterator& aSearchEnd )
892 {
893 return FindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, nsCaseInsensitiveCStringComparator());
894 }
896 bool
897 RFindInReadable( const nsAString& aPattern, nsAString::const_iterator& aSearchStart, nsAString::const_iterator& aSearchEnd, const nsStringComparator& aComparator)
898 {
899 return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
900 }
902 bool
903 RFindInReadable( const nsACString& aPattern, nsACString::const_iterator& aSearchStart, nsACString::const_iterator& aSearchEnd, const nsCStringComparator& aComparator)
904 {
905 return RFindInReadable_Impl(aPattern, aSearchStart, aSearchEnd, aComparator);
906 }
908 bool
909 FindCharInReadable( char16_t aChar, nsAString::const_iterator& aSearchStart, const nsAString::const_iterator& aSearchEnd )
910 {
911 int32_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
913 const char16_t* charFoundAt = nsCharTraits<char16_t>::find(aSearchStart.get(), fragmentLength, aChar);
914 if ( charFoundAt ) {
915 aSearchStart.advance( charFoundAt - aSearchStart.get() );
916 return true;
917 }
919 aSearchStart.advance(fragmentLength);
920 return false;
921 }
923 bool
924 FindCharInReadable( char aChar, nsACString::const_iterator& aSearchStart, const nsACString::const_iterator& aSearchEnd )
925 {
926 int32_t fragmentLength = aSearchEnd.get() - aSearchStart.get();
928 const char* charFoundAt = nsCharTraits<char>::find(aSearchStart.get(), fragmentLength, aChar);
929 if ( charFoundAt ) {
930 aSearchStart.advance( charFoundAt - aSearchStart.get() );
931 return true;
932 }
934 aSearchStart.advance(fragmentLength);
935 return false;
936 }
938 uint32_t
939 CountCharInReadable( const nsAString& aStr,
940 char16_t aChar )
941 {
942 uint32_t count = 0;
943 nsAString::const_iterator begin, end;
945 aStr.BeginReading(begin);
946 aStr.EndReading(end);
948 while (begin != end) {
949 if (*begin == aChar) {
950 ++count;
951 }
952 ++begin;
953 }
955 return count;
956 }
958 uint32_t
959 CountCharInReadable( const nsACString& aStr,
960 char aChar )
961 {
962 uint32_t count = 0;
963 nsACString::const_iterator begin, end;
965 aStr.BeginReading(begin);
966 aStr.EndReading(end);
968 while (begin != end) {
969 if (*begin == aChar) {
970 ++count;
971 }
972 ++begin;
973 }
975 return count;
976 }
978 bool
979 StringBeginsWith( const nsAString& aSource, const nsAString& aSubstring,
980 const nsStringComparator& aComparator )
981 {
982 nsAString::size_type src_len = aSource.Length(),
983 sub_len = aSubstring.Length();
984 if (sub_len > src_len)
985 return false;
986 return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
987 }
989 bool
990 StringBeginsWith( const nsACString& aSource, const nsACString& aSubstring,
991 const nsCStringComparator& aComparator )
992 {
993 nsACString::size_type src_len = aSource.Length(),
994 sub_len = aSubstring.Length();
995 if (sub_len > src_len)
996 return false;
997 return Substring(aSource, 0, sub_len).Equals(aSubstring, aComparator);
998 }
1000 bool
1001 StringEndsWith( const nsAString& aSource, const nsAString& aSubstring,
1002 const nsStringComparator& aComparator )
1003 {
1004 nsAString::size_type src_len = aSource.Length(),
1005 sub_len = aSubstring.Length();
1006 if (sub_len > src_len)
1007 return false;
1008 return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring,
1009 aComparator);
1010 }
1012 bool
1013 StringEndsWith( const nsACString& aSource, const nsACString& aSubstring,
1014 const nsCStringComparator& aComparator )
1015 {
1016 nsACString::size_type src_len = aSource.Length(),
1017 sub_len = aSubstring.Length();
1018 if (sub_len > src_len)
1019 return false;
1020 return Substring(aSource, src_len - sub_len, sub_len).Equals(aSubstring,
1021 aComparator);
1022 }
1026 static const char16_t empty_buffer[1] = { '\0' };
1028 const nsAFlatString&
1029 EmptyString()
1030 {
1031 static const nsDependentString sEmpty(empty_buffer);
1033 return sEmpty;
1034 }
1036 const nsAFlatCString&
1037 EmptyCString()
1038 {
1039 static const nsDependentCString sEmpty((const char *)empty_buffer);
1041 return sEmpty;
1042 }
1044 const nsAFlatString&
1045 NullString()
1046 {
1047 static const nsXPIDLString sNull;
1049 return sNull;
1050 }
1052 const nsAFlatCString&
1053 NullCString()
1054 {
1055 static const nsXPIDLCString sNull;
1057 return sNull;
1058 }
1060 int32_t
1061 CompareUTF8toUTF16(const nsASingleFragmentCString& aUTF8String,
1062 const nsASingleFragmentString& aUTF16String)
1063 {
1064 static const uint32_t NOT_ASCII = uint32_t(~0x7F);
1066 const char *u8, *u8end;
1067 aUTF8String.BeginReading(u8);
1068 aUTF8String.EndReading(u8end);
1070 const char16_t *u16, *u16end;
1071 aUTF16String.BeginReading(u16);
1072 aUTF16String.EndReading(u16end);
1074 while (u8 != u8end && u16 != u16end)
1075 {
1076 // Cast away the signedness of *u8 to prevent signextension when
1077 // converting to uint32_t
1078 uint32_t c8_32 = (uint8_t)*u8;
1080 if (c8_32 & NOT_ASCII)
1081 {
1082 bool err;
1083 c8_32 = UTF8CharEnumerator::NextChar(&u8, u8end, &err);
1084 if (err)
1085 return INT32_MIN;
1087 uint32_t c16_32 = UTF16CharEnumerator::NextChar(&u16, u16end);
1088 // The above UTF16CharEnumerator::NextChar() calls can
1089 // fail, but if it does for anything other than no data to
1090 // look at (which can't happen here), it returns the
1091 // Unicode replacement character 0xFFFD for the invalid
1092 // data they were fed. Ignore that error and treat invalid
1093 // UTF16 as 0xFFFD.
1094 //
1095 // This matches what our UTF16 to UTF8 conversion code
1096 // does, and thus a UTF8 string that came from an invalid
1097 // UTF16 string will compare equal to the invalid UTF16
1098 // string it came from. Same is true for any other UTF16
1099 // string differs only in the invalid part of the string.
1101 if (c8_32 != c16_32)
1102 return c8_32 < c16_32 ? -1 : 1;
1103 }
1104 else
1105 {
1106 if (c8_32 != *u16)
1107 return c8_32 > *u16 ? 1 : -1;
1109 ++u8;
1110 ++u16;
1111 }
1112 }
1114 if (u8 != u8end)
1115 {
1116 // We get to the end of the UTF16 string, but no to the end of
1117 // the UTF8 string. The UTF8 string is longer than the UTF16
1118 // string
1120 return 1;
1121 }
1123 if (u16 != u16end)
1124 {
1125 // We get to the end of the UTF8 string, but no to the end of
1126 // the UTF16 string. The UTF16 string is longer than the UTF8
1127 // string
1129 return -1;
1130 }
1132 // The two strings match.
1134 return 0;
1135 }
1137 void
1138 AppendUCS4ToUTF16(const uint32_t aSource, nsAString& aDest)
1139 {
1140 NS_ASSERTION(IS_VALID_CHAR(aSource), "Invalid UCS4 char");
1141 if (IS_IN_BMP(aSource))
1142 {
1143 aDest.Append(char16_t(aSource));
1144 }
1145 else
1146 {
1147 aDest.Append(H_SURROGATE(aSource));
1148 aDest.Append(L_SURROGATE(aSource));
1149 }
1150 }
