1 | // © 2016 and later: Unicode, Inc. and others. |
2 | // License & terms of use: http://www.unicode.org/copyright.html |
3 | /* |
4 | ******************************************************************************* |
5 | * |
6 | * Copyright (C) 2005-2016, International Business Machines |
7 | * Corporation and others. All Rights Reserved. |
8 | * |
9 | ******************************************************************************* |
10 | * file name: utext.cpp |
11 | * encoding: UTF-8 |
12 | * tab size: 8 (not used) |
13 | * indentation:4 |
14 | * |
15 | * created on: 2005apr12 |
16 | * created by: Markus W. Scherer |
17 | */ |
18 | |
19 | #include "unicode/utypes.h" |
20 | #include "unicode/ustring.h" |
21 | #include "unicode/unistr.h" |
22 | #include "unicode/chariter.h" |
23 | #include "unicode/utext.h" |
24 | #include "unicode/utf.h" |
25 | #include "unicode/utf8.h" |
26 | #include "unicode/utf16.h" |
27 | #include "ustr_imp.h" |
28 | #include "cmemory.h" |
29 | #include "cstring.h" |
30 | #include "uassert.h" |
31 | #include "putilimp.h" |
32 | |
33 | U_NAMESPACE_USE |
34 | |
35 | #define I32_FLAG(bitIndex) ((int32_t)1<<(bitIndex)) |
36 | |
37 | |
38 | static UBool |
39 | utext_access(UText *ut, int64_t index, UBool forward) { |
40 | return ut->pFuncs->access(ut, index, forward); |
41 | } |
42 | |
43 | |
44 | |
45 | U_CAPI UBool U_EXPORT2 |
46 | utext_moveIndex32(UText *ut, int32_t delta) { |
47 | UChar32 c; |
48 | if (delta > 0) { |
49 | do { |
50 | if(ut->chunkOffset>=ut->chunkLength && !utext_access(ut, ut->chunkNativeLimit, TRUE)) { |
51 | return FALSE; |
52 | } |
53 | c = ut->chunkContents[ut->chunkOffset]; |
54 | if (U16_IS_SURROGATE(c)) { |
55 | c = utext_next32(ut); |
56 | if (c == U_SENTINEL) { |
57 | return FALSE; |
58 | } |
59 | } else { |
60 | ut->chunkOffset++; |
61 | } |
62 | } while(--delta>0); |
63 | |
64 | } else if (delta<0) { |
65 | do { |
66 | if(ut->chunkOffset<=0 && !utext_access(ut, ut->chunkNativeStart, FALSE)) { |
67 | return FALSE; |
68 | } |
69 | c = ut->chunkContents[ut->chunkOffset-1]; |
70 | if (U16_IS_SURROGATE(c)) { |
71 | c = utext_previous32(ut); |
72 | if (c == U_SENTINEL) { |
73 | return FALSE; |
74 | } |
75 | } else { |
76 | ut->chunkOffset--; |
77 | } |
78 | } while(++delta<0); |
79 | } |
80 | |
81 | return TRUE; |
82 | } |
83 | |
84 | |
85 | U_CAPI int64_t U_EXPORT2 |
86 | utext_nativeLength(UText *ut) { |
87 | return ut->pFuncs->nativeLength(ut); |
88 | } |
89 | |
90 | |
91 | U_CAPI UBool U_EXPORT2 |
92 | utext_isLengthExpensive(const UText *ut) { |
93 | UBool r = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE)) != 0; |
94 | return r; |
95 | } |
96 | |
97 | |
98 | U_CAPI int64_t U_EXPORT2 |
99 | utext_getNativeIndex(const UText *ut) { |
100 | if(ut->chunkOffset <= ut->nativeIndexingLimit) { |
101 | return ut->chunkNativeStart+ut->chunkOffset; |
102 | } else { |
103 | return ut->pFuncs->mapOffsetToNative(ut); |
104 | } |
105 | } |
106 | |
107 | |
108 | U_CAPI void U_EXPORT2 |
109 | utext_setNativeIndex(UText *ut, int64_t index) { |
110 | if(index<ut->chunkNativeStart || index>=ut->chunkNativeLimit) { |
111 | // The desired position is outside of the current chunk. |
112 | // Access the new position. Assume a forward iteration from here, |
113 | // which will also be optimimum for a single random access. |
114 | // Reverse iterations may suffer slightly. |
115 | ut->pFuncs->access(ut, index, TRUE); |
116 | } else if((int32_t)(index - ut->chunkNativeStart) <= ut->nativeIndexingLimit) { |
117 | // utf-16 indexing. |
118 | ut->chunkOffset=(int32_t)(index-ut->chunkNativeStart); |
119 | } else { |
120 | ut->chunkOffset=ut->pFuncs->mapNativeIndexToUTF16(ut, index); |
121 | } |
122 | // The convention is that the index must always be on a code point boundary. |
123 | // Adjust the index position if it is in the middle of a surrogate pair. |
124 | if (ut->chunkOffset<ut->chunkLength) { |
125 | UChar c= ut->chunkContents[ut->chunkOffset]; |
126 | if (U16_IS_TRAIL(c)) { |
127 | if (ut->chunkOffset==0) { |
128 | ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE); |
129 | } |
130 | if (ut->chunkOffset>0) { |
131 | UChar lead = ut->chunkContents[ut->chunkOffset-1]; |
132 | if (U16_IS_LEAD(lead)) { |
133 | ut->chunkOffset--; |
134 | } |
135 | } |
136 | } |
137 | } |
138 | } |
139 | |
140 | |
141 | |
142 | U_CAPI int64_t U_EXPORT2 |
143 | utext_getPreviousNativeIndex(UText *ut) { |
144 | // |
145 | // Fast-path the common case. |
146 | // Common means current position is not at the beginning of a chunk |
147 | // and the preceding character is not supplementary. |
148 | // |
149 | int32_t i = ut->chunkOffset - 1; |
150 | int64_t result; |
151 | if (i >= 0) { |
152 | UChar c = ut->chunkContents[i]; |
153 | if (U16_IS_TRAIL(c) == FALSE) { |
154 | if (i <= ut->nativeIndexingLimit) { |
155 | result = ut->chunkNativeStart + i; |
156 | } else { |
157 | ut->chunkOffset = i; |
158 | result = ut->pFuncs->mapOffsetToNative(ut); |
159 | ut->chunkOffset++; |
160 | } |
161 | return result; |
162 | } |
163 | } |
164 | |
165 | // If at the start of text, simply return 0. |
166 | if (ut->chunkOffset==0 && ut->chunkNativeStart==0) { |
167 | return 0; |
168 | } |
169 | |
170 | // Harder, less common cases. We are at a chunk boundary, or on a surrogate. |
171 | // Keep it simple, use other functions to handle the edges. |
172 | // |
173 | utext_previous32(ut); |
174 | result = UTEXT_GETNATIVEINDEX(ut); |
175 | utext_next32(ut); |
176 | return result; |
177 | } |
178 | |
179 | |
180 | // |
181 | // utext_current32. Get the UChar32 at the current position. |
182 | // UText iteration position is always on a code point boundary, |
183 | // never on the trail half of a surrogate pair. |
184 | // |
185 | U_CAPI UChar32 U_EXPORT2 |
186 | utext_current32(UText *ut) { |
187 | UChar32 c; |
188 | if (ut->chunkOffset==ut->chunkLength) { |
189 | // Current position is just off the end of the chunk. |
190 | if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) { |
191 | // Off the end of the text. |
192 | return U_SENTINEL; |
193 | } |
194 | } |
195 | |
196 | c = ut->chunkContents[ut->chunkOffset]; |
197 | if (U16_IS_LEAD(c) == FALSE) { |
198 | // Normal, non-supplementary case. |
199 | return c; |
200 | } |
201 | |
202 | // |
203 | // Possible supplementary char. |
204 | // |
205 | UChar32 trail = 0; |
206 | UChar32 supplementaryC = c; |
207 | if ((ut->chunkOffset+1) < ut->chunkLength) { |
208 | // The trail surrogate is in the same chunk. |
209 | trail = ut->chunkContents[ut->chunkOffset+1]; |
210 | } else { |
211 | // The trail surrogate is in a different chunk. |
212 | // Because we must maintain the iteration position, we need to switch forward |
213 | // into the new chunk, get the trail surrogate, then revert the chunk back to the |
214 | // original one. |
215 | // An edge case to be careful of: the entire text may end with an unpaired |
216 | // leading surrogate. The attempt to access the trail will fail, but |
217 | // the original position before the unpaired lead still needs to be restored. |
218 | int64_t nativePosition = ut->chunkNativeLimit; |
219 | int32_t originalOffset = ut->chunkOffset; |
220 | if (ut->pFuncs->access(ut, nativePosition, TRUE)) { |
221 | trail = ut->chunkContents[ut->chunkOffset]; |
222 | } |
223 | UBool r = ut->pFuncs->access(ut, nativePosition, FALSE); // reverse iteration flag loads preceding chunk |
224 | U_ASSERT(r==TRUE); |
225 | ut->chunkOffset = originalOffset; |
226 | if(!r) { |
227 | return U_SENTINEL; |
228 | } |
229 | } |
230 | |
231 | if (U16_IS_TRAIL(trail)) { |
232 | supplementaryC = U16_GET_SUPPLEMENTARY(c, trail); |
233 | } |
234 | return supplementaryC; |
235 | |
236 | } |
237 | |
238 | |
239 | U_CAPI UChar32 U_EXPORT2 |
240 | utext_char32At(UText *ut, int64_t nativeIndex) { |
241 | UChar32 c = U_SENTINEL; |
242 | |
243 | // Fast path the common case. |
244 | if (nativeIndex>=ut->chunkNativeStart && nativeIndex < ut->chunkNativeStart + ut->nativeIndexingLimit) { |
245 | ut->chunkOffset = (int32_t)(nativeIndex - ut->chunkNativeStart); |
246 | c = ut->chunkContents[ut->chunkOffset]; |
247 | if (U16_IS_SURROGATE(c) == FALSE) { |
248 | return c; |
249 | } |
250 | } |
251 | |
252 | |
253 | utext_setNativeIndex(ut, nativeIndex); |
254 | if (nativeIndex>=ut->chunkNativeStart && ut->chunkOffset<ut->chunkLength) { |
255 | c = ut->chunkContents[ut->chunkOffset]; |
256 | if (U16_IS_SURROGATE(c)) { |
257 | // For surrogates, let current32() deal with the complications |
258 | // of supplementaries that may span chunk boundaries. |
259 | c = utext_current32(ut); |
260 | } |
261 | } |
262 | return c; |
263 | } |
264 | |
265 | |
266 | U_CAPI UChar32 U_EXPORT2 |
267 | utext_next32(UText *ut) { |
268 | UChar32 c; |
269 | |
270 | if (ut->chunkOffset >= ut->chunkLength) { |
271 | if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) { |
272 | return U_SENTINEL; |
273 | } |
274 | } |
275 | |
276 | c = ut->chunkContents[ut->chunkOffset++]; |
277 | if (U16_IS_LEAD(c) == FALSE) { |
278 | // Normal case, not supplementary. |
279 | // (A trail surrogate seen here is just returned as is, as a surrogate value. |
280 | // It cannot be part of a pair.) |
281 | return c; |
282 | } |
283 | |
284 | if (ut->chunkOffset >= ut->chunkLength) { |
285 | if (ut->pFuncs->access(ut, ut->chunkNativeLimit, TRUE) == FALSE) { |
286 | // c is an unpaired lead surrogate at the end of the text. |
287 | // return it as it is. |
288 | return c; |
289 | } |
290 | } |
291 | UChar32 trail = ut->chunkContents[ut->chunkOffset]; |
292 | if (U16_IS_TRAIL(trail) == FALSE) { |
293 | // c was an unpaired lead surrogate, not at the end of the text. |
294 | // return it as it is (unpaired). Iteration position is on the |
295 | // following character, possibly in the next chunk, where the |
296 | // trail surrogate would have been if it had existed. |
297 | return c; |
298 | } |
299 | |
300 | UChar32 supplementary = U16_GET_SUPPLEMENTARY(c, trail); |
301 | ut->chunkOffset++; // move iteration position over the trail surrogate. |
302 | return supplementary; |
303 | } |
304 | |
305 | |
306 | U_CAPI UChar32 U_EXPORT2 |
307 | utext_previous32(UText *ut) { |
308 | UChar32 c; |
309 | |
310 | if (ut->chunkOffset <= 0) { |
311 | if (ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE) == FALSE) { |
312 | return U_SENTINEL; |
313 | } |
314 | } |
315 | ut->chunkOffset--; |
316 | c = ut->chunkContents[ut->chunkOffset]; |
317 | if (U16_IS_TRAIL(c) == FALSE) { |
318 | // Normal case, not supplementary. |
319 | // (A lead surrogate seen here is just returned as is, as a surrogate value. |
320 | // It cannot be part of a pair.) |
321 | return c; |
322 | } |
323 | |
324 | if (ut->chunkOffset <= 0) { |
325 | if (ut->pFuncs->access(ut, ut->chunkNativeStart, FALSE) == FALSE) { |
326 | // c is an unpaired trail surrogate at the start of the text. |
327 | // return it as it is. |
328 | return c; |
329 | } |
330 | } |
331 | |
332 | UChar32 lead = ut->chunkContents[ut->chunkOffset-1]; |
333 | if (U16_IS_LEAD(lead) == FALSE) { |
334 | // c was an unpaired trail surrogate, not at the end of the text. |
335 | // return it as it is (unpaired). Iteration position is at c |
336 | return c; |
337 | } |
338 | |
339 | UChar32 supplementary = U16_GET_SUPPLEMENTARY(lead, c); |
340 | ut->chunkOffset--; // move iteration position over the lead surrogate. |
341 | return supplementary; |
342 | } |
343 | |
344 | |
345 | |
346 | U_CAPI UChar32 U_EXPORT2 |
347 | utext_next32From(UText *ut, int64_t index) { |
348 | UChar32 c = U_SENTINEL; |
349 | |
350 | if(index<ut->chunkNativeStart || index>=ut->chunkNativeLimit) { |
351 | // Desired position is outside of the current chunk. |
352 | if(!ut->pFuncs->access(ut, index, TRUE)) { |
353 | // no chunk available here |
354 | return U_SENTINEL; |
355 | } |
356 | } else if (index - ut->chunkNativeStart <= (int64_t)ut->nativeIndexingLimit) { |
357 | // Desired position is in chunk, with direct 1:1 native to UTF16 indexing |
358 | ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart); |
359 | } else { |
360 | // Desired position is in chunk, with non-UTF16 indexing. |
361 | ut->chunkOffset = ut->pFuncs->mapNativeIndexToUTF16(ut, index); |
362 | } |
363 | |
364 | c = ut->chunkContents[ut->chunkOffset++]; |
365 | if (U16_IS_SURROGATE(c)) { |
366 | // Surrogates. Many edge cases. Use other functions that already |
367 | // deal with the problems. |
368 | utext_setNativeIndex(ut, index); |
369 | c = utext_next32(ut); |
370 | } |
371 | return c; |
372 | } |
373 | |
374 | |
375 | U_CAPI UChar32 U_EXPORT2 |
376 | utext_previous32From(UText *ut, int64_t index) { |
377 | // |
378 | // Return the character preceding the specified index. |
379 | // Leave the iteration position at the start of the character that was returned. |
380 | // |
381 | UChar32 cPrev; // The character preceding cCurr, which is what we will return. |
382 | |
383 | // Address the chunk containg the position preceding the incoming index |
384 | // A tricky edge case: |
385 | // We try to test the requested native index against the chunkNativeStart to determine |
386 | // whether the character preceding the one at the index is in the current chunk. |
387 | // BUT, this test can fail with UTF-8 (or any other multibyte encoding), when the |
388 | // requested index is on something other than the first position of the first char. |
389 | // |
390 | if(index<=ut->chunkNativeStart || index>ut->chunkNativeLimit) { |
391 | // Requested native index is outside of the current chunk. |
392 | if(!ut->pFuncs->access(ut, index, FALSE)) { |
393 | // no chunk available here |
394 | return U_SENTINEL; |
395 | } |
396 | } else if(index - ut->chunkNativeStart <= (int64_t)ut->nativeIndexingLimit) { |
397 | // Direct UTF-16 indexing. |
398 | ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart); |
399 | } else { |
400 | ut->chunkOffset=ut->pFuncs->mapNativeIndexToUTF16(ut, index); |
401 | if (ut->chunkOffset==0 && !ut->pFuncs->access(ut, index, FALSE)) { |
402 | // no chunk available here |
403 | return U_SENTINEL; |
404 | } |
405 | } |
406 | |
407 | // |
408 | // Simple case with no surrogates. |
409 | // |
410 | ut->chunkOffset--; |
411 | cPrev = ut->chunkContents[ut->chunkOffset]; |
412 | |
413 | if (U16_IS_SURROGATE(cPrev)) { |
414 | // Possible supplementary. Many edge cases. |
415 | // Let other functions do the heavy lifting. |
416 | utext_setNativeIndex(ut, index); |
417 | cPrev = utext_previous32(ut); |
418 | } |
419 | return cPrev; |
420 | } |
421 | |
422 | |
423 | U_CAPI int32_t U_EXPORT2 |
424 | utext_extract(UText *ut, |
425 | int64_t start, int64_t limit, |
426 | UChar *dest, int32_t destCapacity, |
427 | UErrorCode *status) { |
428 | return ut->pFuncs->extract(ut, start, limit, dest, destCapacity, status); |
429 | } |
430 | |
431 | |
432 | |
433 | U_CAPI UBool U_EXPORT2 |
434 | utext_equals(const UText *a, const UText *b) { |
435 | if (a==NULL || b==NULL || |
436 | a->magic != UTEXT_MAGIC || |
437 | b->magic != UTEXT_MAGIC) { |
438 | // Null or invalid arguments don't compare equal to anything. |
439 | return FALSE; |
440 | } |
441 | |
442 | if (a->pFuncs != b->pFuncs) { |
443 | // Different types of text providers. |
444 | return FALSE; |
445 | } |
446 | |
447 | if (a->context != b->context) { |
448 | // Different sources (different strings) |
449 | return FALSE; |
450 | } |
451 | if (utext_getNativeIndex(a) != utext_getNativeIndex(b)) { |
452 | // Different current position in the string. |
453 | return FALSE; |
454 | } |
455 | |
456 | return TRUE; |
457 | } |
458 | |
459 | U_CAPI UBool U_EXPORT2 |
460 | utext_isWritable(const UText *ut) |
461 | { |
462 | UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) != 0; |
463 | return b; |
464 | } |
465 | |
466 | |
467 | U_CAPI void U_EXPORT2 |
468 | utext_freeze(UText *ut) { |
469 | // Zero out the WRITABLE flag. |
470 | ut->providerProperties &= ~(I32_FLAG(UTEXT_PROVIDER_WRITABLE)); |
471 | } |
472 | |
473 | |
474 | U_CAPI UBool U_EXPORT2 |
475 | utext_hasMetaData(const UText *ut) |
476 | { |
477 | UBool b = (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA)) != 0; |
478 | return b; |
479 | } |
480 | |
481 | |
482 | |
483 | U_CAPI int32_t U_EXPORT2 |
484 | utext_replace(UText *ut, |
485 | int64_t nativeStart, int64_t nativeLimit, |
486 | const UChar *replacementText, int32_t replacementLength, |
487 | UErrorCode *status) |
488 | { |
489 | if (U_FAILURE(*status)) { |
490 | return 0; |
491 | } |
492 | if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) { |
493 | *status = U_NO_WRITE_PERMISSION; |
494 | return 0; |
495 | } |
496 | int32_t i = ut->pFuncs->replace(ut, nativeStart, nativeLimit, replacementText, replacementLength, status); |
497 | return i; |
498 | } |
499 | |
500 | U_CAPI void U_EXPORT2 |
501 | utext_copy(UText *ut, |
502 | int64_t nativeStart, int64_t nativeLimit, |
503 | int64_t destIndex, |
504 | UBool move, |
505 | UErrorCode *status) |
506 | { |
507 | if (U_FAILURE(*status)) { |
508 | return; |
509 | } |
510 | if ((ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_WRITABLE)) == 0) { |
511 | *status = U_NO_WRITE_PERMISSION; |
512 | return; |
513 | } |
514 | ut->pFuncs->copy(ut, nativeStart, nativeLimit, destIndex, move, status); |
515 | } |
516 | |
517 | |
518 | |
519 | U_CAPI UText * U_EXPORT2 |
520 | utext_clone(UText *dest, const UText *src, UBool deep, UBool readOnly, UErrorCode *status) { |
521 | if (U_FAILURE(*status)) { |
522 | return dest; |
523 | } |
524 | UText *result = src->pFuncs->clone(dest, src, deep, status); |
525 | if (U_FAILURE(*status)) { |
526 | return result; |
527 | } |
528 | if (result == NULL) { |
529 | *status = U_MEMORY_ALLOCATION_ERROR; |
530 | return result; |
531 | } |
532 | if (readOnly) { |
533 | utext_freeze(result); |
534 | } |
535 | return result; |
536 | } |
537 | |
538 | |
539 | |
540 | //------------------------------------------------------------------------------ |
541 | // |
542 | // UText common functions implementation |
543 | // |
544 | //------------------------------------------------------------------------------ |
545 | |
546 | // |
547 | // UText.flags bit definitions |
548 | // |
549 | enum { |
550 | UTEXT_HEAP_ALLOCATED = 1, // 1 if ICU has allocated this UText struct on the heap. |
551 | // 0 if caller provided storage for the UText. |
552 | |
553 | = 2, // 1 if ICU has allocated extra storage as a separate |
554 | // heap block. |
555 | // 0 if there is no separate allocation. Either no extra |
556 | // storage was requested, or it is appended to the end |
557 | // of the main UText storage. |
558 | |
559 | UTEXT_OPEN = 4 // 1 if this UText is currently open |
560 | // 0 if this UText is not open. |
561 | }; |
562 | |
563 | |
564 | // |
565 | // Extended form of a UText. The purpose is to aid in computing the total size required |
566 | // when a provider asks for a UText to be allocated with extra storage. |
567 | |
568 | struct ExtendedUText { |
569 | UText ut; |
570 | max_align_t extension; |
571 | }; |
572 | |
573 | static const UText emptyText = UTEXT_INITIALIZER; |
574 | |
575 | U_CAPI UText * U_EXPORT2 |
576 | utext_setup(UText *ut, int32_t , UErrorCode *status) { |
577 | if (U_FAILURE(*status)) { |
578 | return ut; |
579 | } |
580 | |
581 | if (ut == NULL) { |
582 | // We need to heap-allocate storage for the new UText |
583 | int32_t spaceRequired = sizeof(UText); |
584 | if (extraSpace > 0) { |
585 | spaceRequired = sizeof(ExtendedUText) + extraSpace - sizeof(max_align_t); |
586 | } |
587 | ut = (UText *)uprv_malloc(spaceRequired); |
588 | if (ut == NULL) { |
589 | *status = U_MEMORY_ALLOCATION_ERROR; |
590 | return NULL; |
591 | } else { |
592 | *ut = emptyText; |
593 | ut->flags |= UTEXT_HEAP_ALLOCATED; |
594 | if (spaceRequired>0) { |
595 | ut->extraSize = extraSpace; |
596 | ut->pExtra = &((ExtendedUText *)ut)->extension; |
597 | } |
598 | } |
599 | } else { |
600 | // We have been supplied with an already existing UText. |
601 | // Verify that it really appears to be a UText. |
602 | if (ut->magic != UTEXT_MAGIC) { |
603 | *status = U_ILLEGAL_ARGUMENT_ERROR; |
604 | return ut; |
605 | } |
606 | // If the ut is already open and there's a provider supplied close |
607 | // function, call it. |
608 | if ((ut->flags & UTEXT_OPEN) && ut->pFuncs->close != NULL) { |
609 | ut->pFuncs->close(ut); |
610 | } |
611 | ut->flags &= ~UTEXT_OPEN; |
612 | |
613 | // If extra space was requested by our caller, check whether |
614 | // sufficient already exists, and allocate new if needed. |
615 | if (extraSpace > ut->extraSize) { |
616 | // Need more space. If there is existing separately allocated space, |
617 | // delete it first, then allocate new space. |
618 | if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) { |
619 | uprv_free(ut->pExtra); |
620 | ut->extraSize = 0; |
621 | } |
622 | ut->pExtra = uprv_malloc(extraSpace); |
623 | if (ut->pExtra == NULL) { |
624 | *status = U_MEMORY_ALLOCATION_ERROR; |
625 | } else { |
626 | ut->extraSize = extraSpace; |
627 | ut->flags |= UTEXT_EXTRA_HEAP_ALLOCATED; |
628 | } |
629 | } |
630 | } |
631 | if (U_SUCCESS(*status)) { |
632 | ut->flags |= UTEXT_OPEN; |
633 | |
634 | // Initialize all remaining fields of the UText. |
635 | // |
636 | ut->context = NULL; |
637 | ut->chunkContents = NULL; |
638 | ut->p = NULL; |
639 | ut->q = NULL; |
640 | ut->r = NULL; |
641 | ut->a = 0; |
642 | ut->b = 0; |
643 | ut->c = 0; |
644 | ut->chunkOffset = 0; |
645 | ut->chunkLength = 0; |
646 | ut->chunkNativeStart = 0; |
647 | ut->chunkNativeLimit = 0; |
648 | ut->nativeIndexingLimit = 0; |
649 | ut->providerProperties = 0; |
650 | ut->privA = 0; |
651 | ut->privB = 0; |
652 | ut->privC = 0; |
653 | ut->privP = NULL; |
654 | if (ut->pExtra!=NULL && ut->extraSize>0) |
655 | uprv_memset(ut->pExtra, 0, ut->extraSize); |
656 | |
657 | } |
658 | return ut; |
659 | } |
660 | |
661 | |
662 | U_CAPI UText * U_EXPORT2 |
663 | utext_close(UText *ut) { |
664 | if (ut==NULL || |
665 | ut->magic != UTEXT_MAGIC || |
666 | (ut->flags & UTEXT_OPEN) == 0) |
667 | { |
668 | // The supplied ut is not an open UText. |
669 | // Do nothing. |
670 | return ut; |
671 | } |
672 | |
673 | // If the provider gave us a close function, call it now. |
674 | // This will clean up anything allocated specifically by the provider. |
675 | if (ut->pFuncs->close != NULL) { |
676 | ut->pFuncs->close(ut); |
677 | } |
678 | ut->flags &= ~UTEXT_OPEN; |
679 | |
680 | // If we (the framework) allocated the UText or subsidiary storage, |
681 | // delete it. |
682 | if (ut->flags & UTEXT_EXTRA_HEAP_ALLOCATED) { |
683 | uprv_free(ut->pExtra); |
684 | ut->pExtra = NULL; |
685 | ut->flags &= ~UTEXT_EXTRA_HEAP_ALLOCATED; |
686 | ut->extraSize = 0; |
687 | } |
688 | |
689 | // Zero out function table of the closed UText. This is a defensive move, |
690 | // inteded to cause applications that inadvertantly use a closed |
691 | // utext to crash with null pointer errors. |
692 | ut->pFuncs = NULL; |
693 | |
694 | if (ut->flags & UTEXT_HEAP_ALLOCATED) { |
695 | // This UText was allocated by UText setup. We need to free it. |
696 | // Clear magic, so we can detect if the user messes up and immediately |
697 | // tries to reopen another UText using the deleted storage. |
698 | ut->magic = 0; |
699 | uprv_free(ut); |
700 | ut = NULL; |
701 | } |
702 | return ut; |
703 | } |
704 | |
705 | |
706 | |
707 | |
708 | // |
709 | // invalidateChunk Reset a chunk to have no contents, so that the next call |
710 | // to access will cause new data to load. |
711 | // This is needed when copy/move/replace operate directly on the |
712 | // backing text, potentially putting it out of sync with the |
713 | // contents in the chunk. |
714 | // |
715 | static void |
716 | invalidateChunk(UText *ut) { |
717 | ut->chunkLength = 0; |
718 | ut->chunkNativeLimit = 0; |
719 | ut->chunkNativeStart = 0; |
720 | ut->chunkOffset = 0; |
721 | ut->nativeIndexingLimit = 0; |
722 | } |
723 | |
724 | // |
725 | // pinIndex Do range pinning on a native index parameter. |
726 | // 64 bit pinning is done in place. |
727 | // 32 bit truncated result is returned as a convenience for |
728 | // use in providers that don't need 64 bits. |
729 | static int32_t |
730 | pinIndex(int64_t &index, int64_t limit) { |
731 | if (index<0) { |
732 | index = 0; |
733 | } else if (index > limit) { |
734 | index = limit; |
735 | } |
736 | return (int32_t)index; |
737 | } |
738 | |
739 | |
740 | U_CDECL_BEGIN |
741 | |
742 | // |
743 | // Pointer relocation function, |
744 | // a utility used by shallow clone. |
745 | // Adjust a pointer that refers to something within one UText (the source) |
746 | // to refer to the same relative offset within a another UText (the target) |
747 | // |
748 | static void adjustPointer(UText *dest, const void **destPtr, const UText *src) { |
749 | // convert all pointers to (char *) so that byte address arithmetic will work. |
750 | char *dptr = (char *)*destPtr; |
751 | char *dUText = (char *)dest; |
752 | char *sUText = (char *)src; |
753 | |
754 | if (dptr >= (char *)src->pExtra && dptr < ((char*)src->pExtra)+src->extraSize) { |
755 | // target ptr was to something within the src UText's pExtra storage. |
756 | // relocate it into the target UText's pExtra region. |
757 | *destPtr = ((char *)dest->pExtra) + (dptr - (char *)src->pExtra); |
758 | } else if (dptr>=sUText && dptr < sUText+src->sizeOfStruct) { |
759 | // target ptr was pointing to somewhere within the source UText itself. |
760 | // Move it to the same offset within the target UText. |
761 | *destPtr = dUText + (dptr-sUText); |
762 | } |
763 | } |
764 | |
765 | |
766 | // |
767 | // Clone. This is a generic copy-the-utext-by-value clone function that can be |
768 | // used as-is with some utext types, and as a helper by other clones. |
769 | // |
770 | static UText * U_CALLCONV |
771 | shallowTextClone(UText * dest, const UText * src, UErrorCode * status) { |
772 | if (U_FAILURE(*status)) { |
773 | return NULL; |
774 | } |
775 | int32_t = src->extraSize; |
776 | |
777 | // |
778 | // Use the generic text_setup to allocate storage if required. |
779 | // |
780 | dest = utext_setup(dest, srcExtraSize, status); |
781 | if (U_FAILURE(*status)) { |
782 | return dest; |
783 | } |
784 | |
785 | // |
786 | // flags (how the UText was allocated) and the pointer to the |
787 | // extra storage must retain the values in the cloned utext that |
788 | // were set up by utext_setup. Save them separately before |
789 | // copying the whole struct. |
790 | // |
791 | void * = dest->pExtra; |
792 | int32_t flags = dest->flags; |
793 | |
794 | |
795 | // |
796 | // Copy the whole UText struct by value. |
797 | // Any "Extra" storage is copied also. |
798 | // |
799 | int sizeToCopy = src->sizeOfStruct; |
800 | if (sizeToCopy > dest->sizeOfStruct) { |
801 | sizeToCopy = dest->sizeOfStruct; |
802 | } |
803 | uprv_memcpy(dest, src, sizeToCopy); |
804 | dest->pExtra = destExtra; |
805 | dest->flags = flags; |
806 | if (srcExtraSize > 0) { |
807 | uprv_memcpy(dest->pExtra, src->pExtra, srcExtraSize); |
808 | } |
809 | |
810 | // |
811 | // Relocate any pointers in the target that refer to the UText itself |
812 | // to point to the cloned copy rather than the original source. |
813 | // |
814 | adjustPointer(dest, &dest->context, src); |
815 | adjustPointer(dest, &dest->p, src); |
816 | adjustPointer(dest, &dest->q, src); |
817 | adjustPointer(dest, &dest->r, src); |
818 | adjustPointer(dest, (const void **)&dest->chunkContents, src); |
819 | |
820 | // The newly shallow-cloned UText does _not_ own the underlying storage for the text. |
821 | // (The source for the clone may or may not have owned the text.) |
822 | |
823 | dest->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT); |
824 | |
825 | return dest; |
826 | } |
827 | |
828 | |
829 | U_CDECL_END |
830 | |
831 | |
832 | |
833 | //------------------------------------------------------------------------------ |
834 | // |
835 | // UText implementation for UTF-8 char * strings (read-only) |
836 | // Limitation: string length must be <= 0x7fffffff in length. |
837 | // (length must for in an int32_t variable) |
838 | // |
839 | // Use of UText data members: |
840 | // context pointer to UTF-8 string |
841 | // utext.b is the input string length (bytes). |
842 | // utext.c Length scanned so far in string |
843 | // (for optimizing finding length of zero terminated strings.) |
844 | // utext.p pointer to the current buffer |
845 | // utext.q pointer to the other buffer. |
846 | // |
847 | //------------------------------------------------------------------------------ |
848 | |
849 | // Chunk size. |
850 | // Must be less than 85 (256/3), because of byte mapping from UChar indexes to native indexes. |
851 | // Worst case is three native bytes to one UChar. (Supplemenaries are 4 native bytes |
852 | // to two UChars.) |
853 | // The longest illegal byte sequence treated as a single error (and converted to U+FFFD) |
854 | // is a three-byte sequence (truncated four-byte sequence). |
855 | // |
856 | enum { UTF8_TEXT_CHUNK_SIZE=32 }; |
857 | |
858 | // |
859 | // UTF8Buf Two of these structs will be set up in the UText's extra allocated space. |
860 | // Each contains the UChar chunk buffer, the to and from native maps, and |
861 | // header info. |
862 | // |
863 | // because backwards iteration fills the buffers starting at the end and |
864 | // working towards the front, the filled part of the buffers may not begin |
865 | // at the start of the available storage for the buffers. |
866 | // |
867 | // Buffer size is one bigger than the specified UTF8_TEXT_CHUNK_SIZE to allow for |
868 | // the last character added being a supplementary, and thus requiring a surrogate |
869 | // pair. Doing this is simpler than checking for the edge case. |
870 | // |
871 | |
872 | struct UTF8Buf { |
873 | int32_t bufNativeStart; // Native index of first char in UChar buf |
874 | int32_t bufNativeLimit; // Native index following last char in buf. |
875 | int32_t bufStartIdx; // First filled position in buf. |
876 | int32_t bufLimitIdx; // Limit of filled range in buf. |
877 | int32_t bufNILimit; // Limit of native indexing part of buf |
878 | int32_t toUCharsMapStart; // Native index corresponding to |
879 | // mapToUChars[0]. |
880 | // Set to bufNativeStart when filling forwards. |
881 | // Set to computed value when filling backwards. |
882 | |
883 | UChar buf[UTF8_TEXT_CHUNK_SIZE+4]; // The UChar buffer. Requires one extra position beyond the |
884 | // the chunk size, to allow for surrogate at the end. |
885 | // Length must be identical to mapToNative array, below, |
886 | // because of the way indexing works when the array is |
887 | // filled backwards during a reverse iteration. Thus, |
888 | // the additional extra size. |
889 | uint8_t mapToNative[UTF8_TEXT_CHUNK_SIZE+4]; // map UChar index in buf to |
890 | // native offset from bufNativeStart. |
891 | // Requires two extra slots, |
892 | // one for a supplementary starting in the last normal position, |
893 | // and one for an entry for the buffer limit position. |
894 | uint8_t mapToUChars[UTF8_TEXT_CHUNK_SIZE*3+6]; // Map native offset from bufNativeStart to |
895 | // correspoding offset in filled part of buf. |
896 | int32_t align; |
897 | }; |
898 | |
899 | U_CDECL_BEGIN |
900 | |
901 | // |
902 | // utf8TextLength |
903 | // |
904 | // Get the length of the string. If we don't already know it, |
905 | // we'll need to scan for the trailing nul. |
906 | // |
907 | static int64_t U_CALLCONV |
908 | utf8TextLength(UText *ut) { |
909 | if (ut->b < 0) { |
910 | // Zero terminated string, and we haven't scanned to the end yet. |
911 | // Scan it now. |
912 | const char *r = (const char *)ut->context + ut->c; |
913 | while (*r != 0) { |
914 | r++; |
915 | } |
916 | if ((r - (const char *)ut->context) < 0x7fffffff) { |
917 | ut->b = (int32_t)(r - (const char *)ut->context); |
918 | } else { |
919 | // Actual string was bigger (more than 2 gig) than we |
920 | // can handle. Clip it to 2 GB. |
921 | ut->b = 0x7fffffff; |
922 | } |
923 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
924 | } |
925 | return ut->b; |
926 | } |
927 | |
928 | |
929 | |
930 | |
931 | |
932 | |
933 | static UBool U_CALLCONV |
934 | utf8TextAccess(UText *ut, int64_t index, UBool forward) { |
935 | // |
936 | // Apologies to those who are allergic to goto statements. |
937 | // Consider each goto to a labelled block to be the equivalent of |
938 | // call the named block as if it were a function(); |
939 | // return; |
940 | // |
941 | const uint8_t *s8=(const uint8_t *)ut->context; |
942 | UTF8Buf *u8b = NULL; |
943 | int32_t length = ut->b; // Length of original utf-8 |
944 | int32_t ix= (int32_t)index; // Requested index, trimmed to 32 bits. |
945 | int32_t mapIndex = 0; |
946 | if (index<0) { |
947 | ix=0; |
948 | } else if (index > 0x7fffffff) { |
949 | // Strings with 64 bit lengths not supported by this UTF-8 provider. |
950 | ix = 0x7fffffff; |
951 | } |
952 | |
953 | // Pin requested index to the string length. |
954 | if (ix>length) { |
955 | if (length>=0) { |
956 | ix=length; |
957 | } else if (ix>=ut->c) { |
958 | // Zero terminated string, and requested index is beyond |
959 | // the region that has already been scanned. |
960 | // Scan up to either the end of the string or to the |
961 | // requested position, whichever comes first. |
962 | while (ut->c<ix && s8[ut->c]!=0) { |
963 | ut->c++; |
964 | } |
965 | // TODO: support for null terminated string length > 32 bits. |
966 | if (s8[ut->c] == 0) { |
967 | // We just found the actual length of the string. |
968 | // Trim the requested index back to that. |
969 | ix = ut->c; |
970 | ut->b = ut->c; |
971 | length = ut->c; |
972 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
973 | } |
974 | } |
975 | } |
976 | |
977 | // |
978 | // Dispatch to the appropriate action for a forward iteration request. |
979 | // |
980 | if (forward) { |
981 | if (ix==ut->chunkNativeLimit) { |
982 | // Check for normal sequential iteration cases first. |
983 | if (ix==length) { |
984 | // Just reached end of string |
985 | // Don't swap buffers, but do set the |
986 | // current buffer position. |
987 | ut->chunkOffset = ut->chunkLength; |
988 | return FALSE; |
989 | } else { |
990 | // End of current buffer. |
991 | // check whether other buffer already has what we need. |
992 | UTF8Buf *altB = (UTF8Buf *)ut->q; |
993 | if (ix>=altB->bufNativeStart && ix<altB->bufNativeLimit) { |
994 | goto swapBuffers; |
995 | } |
996 | } |
997 | } |
998 | |
999 | // A random access. Desired index could be in either or niether buf. |
1000 | // For optimizing the order of testing, first check for the index |
1001 | // being in the other buffer. This will be the case for uses that |
1002 | // move back and forth over a fairly limited range |
1003 | { |
1004 | u8b = (UTF8Buf *)ut->q; // the alternate buffer |
1005 | if (ix>=u8b->bufNativeStart && ix<u8b->bufNativeLimit) { |
1006 | // Requested index is in the other buffer. |
1007 | goto swapBuffers; |
1008 | } |
1009 | if (ix == length) { |
1010 | // Requested index is end-of-string. |
1011 | // (this is the case of randomly seeking to the end. |
1012 | // The case of iterating off the end is handled earlier.) |
1013 | if (ix == ut->chunkNativeLimit) { |
1014 | // Current buffer extends up to the end of the string. |
1015 | // Leave it as the current buffer. |
1016 | ut->chunkOffset = ut->chunkLength; |
1017 | return FALSE; |
1018 | } |
1019 | if (ix == u8b->bufNativeLimit) { |
1020 | // Alternate buffer extends to the end of string. |
1021 | // Swap it in as the current buffer. |
1022 | goto swapBuffersAndFail; |
1023 | } |
1024 | |
1025 | // Neither existing buffer extends to the end of the string. |
1026 | goto makeStubBuffer; |
1027 | } |
1028 | |
1029 | if (ix<ut->chunkNativeStart || ix>=ut->chunkNativeLimit) { |
1030 | // Requested index is in neither buffer. |
1031 | goto fillForward; |
1032 | } |
1033 | |
1034 | // Requested index is in this buffer. |
1035 | u8b = (UTF8Buf *)ut->p; // the current buffer |
1036 | mapIndex = ix - u8b->toUCharsMapStart; |
1037 | U_ASSERT(mapIndex < (int32_t)sizeof(UTF8Buf::mapToUChars)); |
1038 | ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx; |
1039 | return TRUE; |
1040 | |
1041 | } |
1042 | } |
1043 | |
1044 | |
1045 | // |
1046 | // Dispatch to the appropriate action for a |
1047 | // Backwards Diretion iteration request. |
1048 | // |
1049 | if (ix==ut->chunkNativeStart) { |
1050 | // Check for normal sequential iteration cases first. |
1051 | if (ix==0) { |
1052 | // Just reached the start of string |
1053 | // Don't swap buffers, but do set the |
1054 | // current buffer position. |
1055 | ut->chunkOffset = 0; |
1056 | return FALSE; |
1057 | } else { |
1058 | // Start of current buffer. |
1059 | // check whether other buffer already has what we need. |
1060 | UTF8Buf *altB = (UTF8Buf *)ut->q; |
1061 | if (ix>altB->bufNativeStart && ix<=altB->bufNativeLimit) { |
1062 | goto swapBuffers; |
1063 | } |
1064 | } |
1065 | } |
1066 | |
1067 | // A random access. Desired index could be in either or niether buf. |
1068 | // For optimizing the order of testing, |
1069 | // Most likely case: in the other buffer. |
1070 | // Second most likely: in neither buffer. |
1071 | // Unlikely, but must work: in the current buffer. |
1072 | u8b = (UTF8Buf *)ut->q; // the alternate buffer |
1073 | if (ix>u8b->bufNativeStart && ix<=u8b->bufNativeLimit) { |
1074 | // Requested index is in the other buffer. |
1075 | goto swapBuffers; |
1076 | } |
1077 | // Requested index is start-of-string. |
1078 | // (this is the case of randomly seeking to the start. |
1079 | // The case of iterating off the start is handled earlier.) |
1080 | if (ix==0) { |
1081 | if (u8b->bufNativeStart==0) { |
1082 | // Alternate buffer contains the data for the start string. |
1083 | // Make it be the current buffer. |
1084 | goto swapBuffersAndFail; |
1085 | } else { |
1086 | // Request for data before the start of string, |
1087 | // neither buffer is usable. |
1088 | // set up a zero-length buffer. |
1089 | goto makeStubBuffer; |
1090 | } |
1091 | } |
1092 | |
1093 | if (ix<=ut->chunkNativeStart || ix>ut->chunkNativeLimit) { |
1094 | // Requested index is in neither buffer. |
1095 | goto fillReverse; |
1096 | } |
1097 | |
1098 | // Requested index is in this buffer. |
1099 | // Set the utf16 buffer index. |
1100 | u8b = (UTF8Buf *)ut->p; |
1101 | mapIndex = ix - u8b->toUCharsMapStart; |
1102 | ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx; |
1103 | if (ut->chunkOffset==0) { |
1104 | // This occurs when the first character in the text is |
1105 | // a multi-byte UTF-8 char, and the requested index is to |
1106 | // one of the trailing bytes. Because there is no preceding , |
1107 | // character, this access fails. We can't pick up on the |
1108 | // situation sooner because the requested index is not zero. |
1109 | return FALSE; |
1110 | } else { |
1111 | return TRUE; |
1112 | } |
1113 | |
1114 | |
1115 | |
1116 | swapBuffers: |
1117 | // The alternate buffer (ut->q) has the string data that was requested. |
1118 | // Swap the primary and alternate buffers, and set the |
1119 | // chunk index into the new primary buffer. |
1120 | { |
1121 | u8b = (UTF8Buf *)ut->q; |
1122 | ut->q = ut->p; |
1123 | ut->p = u8b; |
1124 | ut->chunkContents = &u8b->buf[u8b->bufStartIdx]; |
1125 | ut->chunkLength = u8b->bufLimitIdx - u8b->bufStartIdx; |
1126 | ut->chunkNativeStart = u8b->bufNativeStart; |
1127 | ut->chunkNativeLimit = u8b->bufNativeLimit; |
1128 | ut->nativeIndexingLimit = u8b->bufNILimit; |
1129 | |
1130 | // Index into the (now current) chunk |
1131 | // Use the map to set the chunk index. It's more trouble than it's worth |
1132 | // to check whether native indexing can be used. |
1133 | U_ASSERT(ix>=u8b->bufNativeStart); |
1134 | U_ASSERT(ix<=u8b->bufNativeLimit); |
1135 | mapIndex = ix - u8b->toUCharsMapStart; |
1136 | U_ASSERT(mapIndex>=0); |
1137 | U_ASSERT(mapIndex<(int32_t)sizeof(u8b->mapToUChars)); |
1138 | ut->chunkOffset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx; |
1139 | |
1140 | return TRUE; |
1141 | } |
1142 | |
1143 | |
1144 | swapBuffersAndFail: |
1145 | // We got a request for either the start or end of the string, |
1146 | // with iteration continuing in the out-of-bounds direction. |
1147 | // The alternate buffer already contains the data up to the |
1148 | // start/end. |
1149 | // Swap the buffers, then return failure, indicating that we couldn't |
1150 | // make things correct for continuing the iteration in the requested |
1151 | // direction. The position & buffer are correct should the |
1152 | // user decide to iterate in the opposite direction. |
1153 | u8b = (UTF8Buf *)ut->q; |
1154 | ut->q = ut->p; |
1155 | ut->p = u8b; |
1156 | ut->chunkContents = &u8b->buf[u8b->bufStartIdx]; |
1157 | ut->chunkLength = u8b->bufLimitIdx - u8b->bufStartIdx; |
1158 | ut->chunkNativeStart = u8b->bufNativeStart; |
1159 | ut->chunkNativeLimit = u8b->bufNativeLimit; |
1160 | ut->nativeIndexingLimit = u8b->bufNILimit; |
1161 | |
1162 | // Index into the (now current) chunk |
1163 | // For this function (swapBuffersAndFail), the requested index |
1164 | // will always be at either the start or end of the chunk. |
1165 | if (ix==u8b->bufNativeLimit) { |
1166 | ut->chunkOffset = ut->chunkLength; |
1167 | } else { |
1168 | ut->chunkOffset = 0; |
1169 | U_ASSERT(ix == u8b->bufNativeStart); |
1170 | } |
1171 | return FALSE; |
1172 | |
1173 | makeStubBuffer: |
1174 | // The user has done a seek/access past the start or end |
1175 | // of the string. Rather than loading data that is likely |
1176 | // to never be used, just set up a zero-length buffer at |
1177 | // the position. |
1178 | u8b = (UTF8Buf *)ut->q; |
1179 | u8b->bufNativeStart = ix; |
1180 | u8b->bufNativeLimit = ix; |
1181 | u8b->bufStartIdx = 0; |
1182 | u8b->bufLimitIdx = 0; |
1183 | u8b->bufNILimit = 0; |
1184 | u8b->toUCharsMapStart = ix; |
1185 | u8b->mapToNative[0] = 0; |
1186 | u8b->mapToUChars[0] = 0; |
1187 | goto swapBuffersAndFail; |
1188 | |
1189 | |
1190 | |
1191 | fillForward: |
1192 | { |
1193 | // Move the incoming index to a code point boundary. |
1194 | U8_SET_CP_START(s8, 0, ix); |
1195 | |
1196 | // Swap the UText buffers. |
1197 | // We want to fill what was previously the alternate buffer, |
1198 | // and make what was the current buffer be the new alternate. |
1199 | UTF8Buf *u8b_swap = (UTF8Buf *)ut->q; |
1200 | ut->q = ut->p; |
1201 | ut->p = u8b_swap; |
1202 | |
1203 | int32_t strLen = ut->b; |
1204 | UBool nulTerminated = FALSE; |
1205 | if (strLen < 0) { |
1206 | strLen = 0x7fffffff; |
1207 | nulTerminated = TRUE; |
1208 | } |
1209 | |
1210 | UChar *buf = u8b_swap->buf; |
1211 | uint8_t *mapToNative = u8b_swap->mapToNative; |
1212 | uint8_t *mapToUChars = u8b_swap->mapToUChars; |
1213 | int32_t destIx = 0; |
1214 | int32_t srcIx = ix; |
1215 | UBool seenNonAscii = FALSE; |
1216 | UChar32 c = 0; |
1217 | |
1218 | // Fill the chunk buffer and mapping arrays. |
1219 | while (destIx<UTF8_TEXT_CHUNK_SIZE) { |
1220 | c = s8[srcIx]; |
1221 | if (c>0 && c<0x80) { |
1222 | // Special case ASCII range for speed. |
1223 | // zero is excluded to simplify bounds checking. |
1224 | buf[destIx] = (UChar)c; |
1225 | mapToNative[destIx] = (uint8_t)(srcIx - ix); |
1226 | mapToUChars[srcIx-ix] = (uint8_t)destIx; |
1227 | srcIx++; |
1228 | destIx++; |
1229 | } else { |
1230 | // General case, handle everything. |
1231 | if (seenNonAscii == FALSE) { |
1232 | seenNonAscii = TRUE; |
1233 | u8b_swap->bufNILimit = destIx; |
1234 | } |
1235 | |
1236 | int32_t cIx = srcIx; |
1237 | int32_t dIx = destIx; |
1238 | int32_t dIxSaved = destIx; |
1239 | U8_NEXT_OR_FFFD(s8, srcIx, strLen, c); |
1240 | if (c==0 && nulTerminated) { |
1241 | srcIx--; |
1242 | break; |
1243 | } |
1244 | |
1245 | U16_APPEND_UNSAFE(buf, destIx, c); |
1246 | do { |
1247 | mapToNative[dIx++] = (uint8_t)(cIx - ix); |
1248 | } while (dIx < destIx); |
1249 | |
1250 | do { |
1251 | mapToUChars[cIx++ - ix] = (uint8_t)dIxSaved; |
1252 | } while (cIx < srcIx); |
1253 | } |
1254 | if (srcIx>=strLen) { |
1255 | break; |
1256 | } |
1257 | |
1258 | } |
1259 | |
1260 | // store Native <--> Chunk Map entries for the end of the buffer. |
1261 | // There is no actual character here, but the index position is valid. |
1262 | mapToNative[destIx] = (uint8_t)(srcIx - ix); |
1263 | mapToUChars[srcIx - ix] = (uint8_t)destIx; |
1264 | |
1265 | // fill in Buffer descriptor |
1266 | u8b_swap->bufNativeStart = ix; |
1267 | u8b_swap->bufNativeLimit = srcIx; |
1268 | u8b_swap->bufStartIdx = 0; |
1269 | u8b_swap->bufLimitIdx = destIx; |
1270 | if (seenNonAscii == FALSE) { |
1271 | u8b_swap->bufNILimit = destIx; |
1272 | } |
1273 | u8b_swap->toUCharsMapStart = u8b_swap->bufNativeStart; |
1274 | |
1275 | // Set UText chunk to refer to this buffer. |
1276 | ut->chunkContents = buf; |
1277 | ut->chunkOffset = 0; |
1278 | ut->chunkLength = u8b_swap->bufLimitIdx; |
1279 | ut->chunkNativeStart = u8b_swap->bufNativeStart; |
1280 | ut->chunkNativeLimit = u8b_swap->bufNativeLimit; |
1281 | ut->nativeIndexingLimit = u8b_swap->bufNILimit; |
1282 | |
1283 | // For zero terminated strings, keep track of the maximum point |
1284 | // scanned so far. |
1285 | if (nulTerminated && srcIx>ut->c) { |
1286 | ut->c = srcIx; |
1287 | if (c==0) { |
1288 | // We scanned to the end. |
1289 | // Remember the actual length. |
1290 | ut->b = srcIx; |
1291 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
1292 | } |
1293 | } |
1294 | return TRUE; |
1295 | } |
1296 | |
1297 | |
1298 | fillReverse: |
1299 | { |
1300 | // Move the incoming index to a code point boundary. |
1301 | // Can only do this if the incoming index is somewhere in the interior of the string. |
1302 | // If index is at the end, there is no character there to look at. |
1303 | if (ix != ut->b) { |
1304 | // Note: this function will only move the index back if it is on a trail byte |
1305 | // and there is a preceding lead byte and the sequence from the lead |
1306 | // through this trail could be part of a valid UTF-8 sequence |
1307 | // Otherwise the index remains unchanged. |
1308 | U8_SET_CP_START(s8, 0, ix); |
1309 | } |
1310 | |
1311 | // Swap the UText buffers. |
1312 | // We want to fill what was previously the alternate buffer, |
1313 | // and make what was the current buffer be the new alternate. |
1314 | UTF8Buf *u8b_swap = (UTF8Buf *)ut->q; |
1315 | ut->q = ut->p; |
1316 | ut->p = u8b_swap; |
1317 | |
1318 | UChar *buf = u8b_swap->buf; |
1319 | uint8_t *mapToNative = u8b_swap->mapToNative; |
1320 | uint8_t *mapToUChars = u8b_swap->mapToUChars; |
1321 | int32_t toUCharsMapStart = ix - sizeof(UTF8Buf::mapToUChars) + 1; |
1322 | // Note that toUCharsMapStart can be negative. Happens when the remaining |
1323 | // text from current position to the beginning is less than the buffer size. |
1324 | // + 1 because mapToUChars must have a slot at the end for the bufNativeLimit entry. |
1325 | int32_t destIx = UTF8_TEXT_CHUNK_SIZE+2; // Start in the overflow region |
1326 | // at end of buffer to leave room |
1327 | // for a surrogate pair at the |
1328 | // buffer start. |
1329 | int32_t srcIx = ix; |
1330 | int32_t bufNILimit = destIx; |
1331 | UChar32 c; |
1332 | |
1333 | // Map to/from Native Indexes, fill in for the position at the end of |
1334 | // the buffer. |
1335 | // |
1336 | mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart); |
1337 | mapToUChars[srcIx - toUCharsMapStart] = (uint8_t)destIx; |
1338 | |
1339 | // Fill the chunk buffer |
1340 | // Work backwards, filling from the end of the buffer towards the front. |
1341 | // |
1342 | while (destIx>2 && (srcIx - toUCharsMapStart > 5) && (srcIx > 0)) { |
1343 | srcIx--; |
1344 | destIx--; |
1345 | |
1346 | // Get last byte of the UTF-8 character |
1347 | c = s8[srcIx]; |
1348 | if (c<0x80) { |
1349 | // Special case ASCII range for speed. |
1350 | buf[destIx] = (UChar)c; |
1351 | U_ASSERT(toUCharsMapStart <= srcIx); |
1352 | mapToUChars[srcIx - toUCharsMapStart] = (uint8_t)destIx; |
1353 | mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart); |
1354 | } else { |
1355 | // General case, handle everything non-ASCII. |
1356 | |
1357 | int32_t sIx = srcIx; // ix of last byte of multi-byte u8 char |
1358 | |
1359 | // Get the full character from the UTF8 string. |
1360 | // use code derived from tbe macros in utf8.h |
1361 | // Leaves srcIx pointing at the first byte of the UTF-8 char. |
1362 | // |
1363 | c=utf8_prevCharSafeBody(s8, 0, &srcIx, c, -3); |
1364 | // leaves srcIx at first byte of the multi-byte char. |
1365 | |
1366 | // Store the character in UTF-16 buffer. |
1367 | if (c<0x10000) { |
1368 | buf[destIx] = (UChar)c; |
1369 | mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart); |
1370 | } else { |
1371 | buf[destIx] = U16_TRAIL(c); |
1372 | mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart); |
1373 | buf[--destIx] = U16_LEAD(c); |
1374 | mapToNative[destIx] = (uint8_t)(srcIx - toUCharsMapStart); |
1375 | } |
1376 | |
1377 | // Fill in the map from native indexes to UChars buf index. |
1378 | do { |
1379 | mapToUChars[sIx-- - toUCharsMapStart] = (uint8_t)destIx; |
1380 | } while (sIx >= srcIx); |
1381 | U_ASSERT(toUCharsMapStart <= (srcIx+1)); |
1382 | |
1383 | // Set native indexing limit to be the current position. |
1384 | // We are processing a non-ascii, non-native-indexing char now; |
1385 | // the limit will be here if the rest of the chars to be |
1386 | // added to this buffer are ascii. |
1387 | bufNILimit = destIx; |
1388 | } |
1389 | } |
1390 | u8b_swap->bufNativeStart = srcIx; |
1391 | u8b_swap->bufNativeLimit = ix; |
1392 | u8b_swap->bufStartIdx = destIx; |
1393 | u8b_swap->bufLimitIdx = UTF8_TEXT_CHUNK_SIZE+2; |
1394 | u8b_swap->bufNILimit = bufNILimit - u8b_swap->bufStartIdx; |
1395 | u8b_swap->toUCharsMapStart = toUCharsMapStart; |
1396 | |
1397 | ut->chunkContents = &buf[u8b_swap->bufStartIdx]; |
1398 | ut->chunkLength = u8b_swap->bufLimitIdx - u8b_swap->bufStartIdx; |
1399 | ut->chunkOffset = ut->chunkLength; |
1400 | ut->chunkNativeStart = u8b_swap->bufNativeStart; |
1401 | ut->chunkNativeLimit = u8b_swap->bufNativeLimit; |
1402 | ut->nativeIndexingLimit = u8b_swap->bufNILimit; |
1403 | return TRUE; |
1404 | } |
1405 | |
1406 | } |
1407 | |
1408 | |
1409 | |
1410 | // |
1411 | // This is a slightly modified copy of u_strFromUTF8, |
1412 | // Inserts a Replacement Char rather than failing on invalid UTF-8 |
1413 | // Removes unnecessary features. |
1414 | // |
1415 | static UChar* |
1416 | utext_strFromUTF8(UChar *dest, |
1417 | int32_t destCapacity, |
1418 | int32_t *pDestLength, |
1419 | const char* src, |
1420 | int32_t srcLength, // required. NUL terminated not supported. |
1421 | UErrorCode *pErrorCode |
1422 | ) |
1423 | { |
1424 | |
1425 | UChar *pDest = dest; |
1426 | UChar *pDestLimit = (dest!=NULL)?(dest+destCapacity):NULL; |
1427 | UChar32 ch=0; |
1428 | int32_t index = 0; |
1429 | int32_t reqLength = 0; |
1430 | uint8_t* pSrc = (uint8_t*) src; |
1431 | |
1432 | |
1433 | while((index < srcLength)&&(pDest<pDestLimit)){ |
1434 | ch = pSrc[index++]; |
1435 | if(ch <=0x7f){ |
1436 | *pDest++=(UChar)ch; |
1437 | }else{ |
1438 | ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -3); |
1439 | if(U_IS_BMP(ch)){ |
1440 | *(pDest++)=(UChar)ch; |
1441 | }else{ |
1442 | *(pDest++)=U16_LEAD(ch); |
1443 | if(pDest<pDestLimit){ |
1444 | *(pDest++)=U16_TRAIL(ch); |
1445 | }else{ |
1446 | reqLength++; |
1447 | break; |
1448 | } |
1449 | } |
1450 | } |
1451 | } |
1452 | /* donot fill the dest buffer just count the UChars needed */ |
1453 | while(index < srcLength){ |
1454 | ch = pSrc[index++]; |
1455 | if(ch <= 0x7f){ |
1456 | reqLength++; |
1457 | }else{ |
1458 | ch=utf8_nextCharSafeBody(pSrc, &index, srcLength, ch, -3); |
1459 | reqLength+=U16_LENGTH(ch); |
1460 | } |
1461 | } |
1462 | |
1463 | reqLength+=(int32_t)(pDest - dest); |
1464 | |
1465 | if(pDestLength){ |
1466 | *pDestLength = reqLength; |
1467 | } |
1468 | |
1469 | /* Terminate the buffer */ |
1470 | u_terminateUChars(dest,destCapacity,reqLength,pErrorCode); |
1471 | |
1472 | return dest; |
1473 | } |
1474 | |
1475 | |
1476 | |
1477 | static int32_t U_CALLCONV |
1478 | (UText *ut, |
1479 | int64_t start, int64_t limit, |
1480 | UChar *dest, int32_t destCapacity, |
1481 | UErrorCode *pErrorCode) { |
1482 | if(U_FAILURE(*pErrorCode)) { |
1483 | return 0; |
1484 | } |
1485 | if(destCapacity<0 || (dest==NULL && destCapacity>0)) { |
1486 | *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
1487 | return 0; |
1488 | } |
1489 | int32_t length = ut->b; |
1490 | int32_t start32 = pinIndex(start, length); |
1491 | int32_t limit32 = pinIndex(limit, length); |
1492 | |
1493 | if(start32>limit32) { |
1494 | *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
1495 | return 0; |
1496 | } |
1497 | |
1498 | |
1499 | // adjust the incoming indexes to land on code point boundaries if needed. |
1500 | // adjust by no more than three, because that is the largest number of trail bytes |
1501 | // in a well formed UTF8 character. |
1502 | const uint8_t *buf = (const uint8_t *)ut->context; |
1503 | int i; |
1504 | if (start32 < ut->chunkNativeLimit) { |
1505 | for (i=0; i<3; i++) { |
1506 | if (U8_IS_SINGLE(buf[start32]) || U8_IS_LEAD(buf[start32]) || start32==0) { |
1507 | break; |
1508 | } |
1509 | start32--; |
1510 | } |
1511 | } |
1512 | |
1513 | if (limit32 < ut->chunkNativeLimit) { |
1514 | for (i=0; i<3; i++) { |
1515 | if (U8_IS_SINGLE(buf[limit32]) || U8_IS_LEAD(buf[limit32]) || limit32==0) { |
1516 | break; |
1517 | } |
1518 | limit32--; |
1519 | } |
1520 | } |
1521 | |
1522 | // Do the actual extract. |
1523 | int32_t destLength=0; |
1524 | utext_strFromUTF8(dest, destCapacity, &destLength, |
1525 | (const char *)ut->context+start32, limit32-start32, |
1526 | pErrorCode); |
1527 | utf8TextAccess(ut, limit32, TRUE); |
1528 | return destLength; |
1529 | } |
1530 | |
1531 | // |
1532 | // utf8TextMapOffsetToNative |
1533 | // |
1534 | // Map a chunk (UTF-16) offset to a native index. |
1535 | static int64_t U_CALLCONV |
1536 | utf8TextMapOffsetToNative(const UText *ut) { |
1537 | // |
1538 | UTF8Buf *u8b = (UTF8Buf *)ut->p; |
1539 | U_ASSERT(ut->chunkOffset>ut->nativeIndexingLimit && ut->chunkOffset<=ut->chunkLength); |
1540 | int32_t nativeOffset = u8b->mapToNative[ut->chunkOffset + u8b->bufStartIdx] + u8b->toUCharsMapStart; |
1541 | U_ASSERT(nativeOffset >= ut->chunkNativeStart && nativeOffset <= ut->chunkNativeLimit); |
1542 | return nativeOffset; |
1543 | } |
1544 | |
1545 | // |
1546 | // Map a native index to the corrsponding chunk offset |
1547 | // |
1548 | static int32_t U_CALLCONV |
1549 | utf8TextMapIndexToUTF16(const UText *ut, int64_t index64) { |
1550 | U_ASSERT(index64 <= 0x7fffffff); |
1551 | int32_t index = (int32_t)index64; |
1552 | UTF8Buf *u8b = (UTF8Buf *)ut->p; |
1553 | U_ASSERT(index>=ut->chunkNativeStart+ut->nativeIndexingLimit); |
1554 | U_ASSERT(index<=ut->chunkNativeLimit); |
1555 | int32_t mapIndex = index - u8b->toUCharsMapStart; |
1556 | U_ASSERT(mapIndex < (int32_t)sizeof(UTF8Buf::mapToUChars)); |
1557 | int32_t offset = u8b->mapToUChars[mapIndex] - u8b->bufStartIdx; |
1558 | U_ASSERT(offset>=0 && offset<=ut->chunkLength); |
1559 | return offset; |
1560 | } |
1561 | |
1562 | static UText * U_CALLCONV |
1563 | utf8TextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) |
1564 | { |
1565 | // First do a generic shallow clone. Does everything needed for the UText struct itself. |
1566 | dest = shallowTextClone(dest, src, status); |
1567 | |
1568 | // For deep clones, make a copy of the string. |
1569 | // The copied storage is owned by the newly created clone. |
1570 | // |
1571 | // TODO: There is an isssue with using utext_nativeLength(). |
1572 | // That function is non-const in cases where the input was NUL terminated |
1573 | // and the length has not yet been determined. |
1574 | // This function (clone()) is const. |
1575 | // There potentially a thread safety issue lurking here. |
1576 | // |
1577 | if (deep && U_SUCCESS(*status)) { |
1578 | int32_t len = (int32_t)utext_nativeLength((UText *)src); |
1579 | char *copyStr = (char *)uprv_malloc(len+1); |
1580 | if (copyStr == NULL) { |
1581 | *status = U_MEMORY_ALLOCATION_ERROR; |
1582 | } else { |
1583 | uprv_memcpy(copyStr, src->context, len+1); |
1584 | dest->context = copyStr; |
1585 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT); |
1586 | } |
1587 | } |
1588 | return dest; |
1589 | } |
1590 | |
1591 | |
1592 | static void U_CALLCONV |
1593 | utf8TextClose(UText *ut) { |
1594 | // Most of the work of close is done by the generic UText framework close. |
1595 | // All that needs to be done here is to delete the UTF8 string if the UText |
1596 | // owns it. This occurs if the UText was created by cloning. |
1597 | if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) { |
1598 | char *s = (char *)ut->context; |
1599 | uprv_free(s); |
1600 | ut->context = NULL; |
1601 | } |
1602 | } |
1603 | |
1604 | U_CDECL_END |
1605 | |
1606 | |
1607 | static const struct UTextFuncs utf8Funcs = |
1608 | { |
1609 | sizeof(UTextFuncs), |
1610 | 0, 0, 0, // Reserved alignment padding |
1611 | utf8TextClone, |
1612 | utf8TextLength, |
1613 | utf8TextAccess, |
1614 | utf8TextExtract, |
1615 | NULL, /* replace*/ |
1616 | NULL, /* copy */ |
1617 | utf8TextMapOffsetToNative, |
1618 | utf8TextMapIndexToUTF16, |
1619 | utf8TextClose, |
1620 | NULL, // spare 1 |
1621 | NULL, // spare 2 |
1622 | NULL // spare 3 |
1623 | }; |
1624 | |
1625 | |
1626 | static const char gEmptyString[] = {0}; |
1627 | |
1628 | U_CAPI UText * U_EXPORT2 |
1629 | utext_openUTF8(UText *ut, const char *s, int64_t length, UErrorCode *status) { |
1630 | if(U_FAILURE(*status)) { |
1631 | return NULL; |
1632 | } |
1633 | if(s==NULL && length==0) { |
1634 | s = gEmptyString; |
1635 | } |
1636 | |
1637 | if(s==NULL || length<-1 || length>INT32_MAX) { |
1638 | *status=U_ILLEGAL_ARGUMENT_ERROR; |
1639 | return NULL; |
1640 | } |
1641 | |
1642 | ut = utext_setup(ut, sizeof(UTF8Buf) * 2, status); |
1643 | if (U_FAILURE(*status)) { |
1644 | return ut; |
1645 | } |
1646 | |
1647 | ut->pFuncs = &utf8Funcs; |
1648 | ut->context = s; |
1649 | ut->b = (int32_t)length; |
1650 | ut->c = (int32_t)length; |
1651 | if (ut->c < 0) { |
1652 | ut->c = 0; |
1653 | ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
1654 | } |
1655 | ut->p = ut->pExtra; |
1656 | ut->q = (char *)ut->pExtra + sizeof(UTF8Buf); |
1657 | return ut; |
1658 | |
1659 | } |
1660 | |
1661 | |
1662 | |
1663 | |
1664 | |
1665 | |
1666 | |
1667 | |
1668 | //------------------------------------------------------------------------------ |
1669 | // |
1670 | // UText implementation wrapper for Replaceable (read/write) |
1671 | // |
1672 | // Use of UText data members: |
1673 | // context pointer to Replaceable. |
1674 | // p pointer to Replaceable if it is owned by the UText. |
1675 | // |
1676 | //------------------------------------------------------------------------------ |
1677 | |
1678 | |
1679 | |
1680 | // minimum chunk size for this implementation: 3 |
1681 | // to allow for possible trimming for code point boundaries |
1682 | enum { REP_TEXT_CHUNK_SIZE=10 }; |
1683 | |
1684 | struct { |
1685 | /* |
1686 | * Chunk UChars. |
1687 | * +1 to simplify filling with surrogate pair at the end. |
1688 | */ |
1689 | UChar [REP_TEXT_CHUNK_SIZE+1]; |
1690 | }; |
1691 | |
1692 | |
1693 | U_CDECL_BEGIN |
1694 | |
1695 | static UText * U_CALLCONV |
1696 | repTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) { |
1697 | // First do a generic shallow clone. Does everything needed for the UText struct itself. |
1698 | dest = shallowTextClone(dest, src, status); |
1699 | |
1700 | // For deep clones, make a copy of the Replaceable. |
1701 | // The copied Replaceable storage is owned by the newly created UText clone. |
1702 | // A non-NULL pointer in UText.p is the signal to the close() function to delete |
1703 | // it. |
1704 | // |
1705 | if (deep && U_SUCCESS(*status)) { |
1706 | const Replaceable *replSrc = (const Replaceable *)src->context; |
1707 | dest->context = replSrc->clone(); |
1708 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT); |
1709 | |
1710 | // with deep clone, the copy is writable, even when the source is not. |
1711 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_WRITABLE); |
1712 | } |
1713 | return dest; |
1714 | } |
1715 | |
1716 | |
1717 | static void U_CALLCONV |
1718 | repTextClose(UText *ut) { |
1719 | // Most of the work of close is done by the generic UText framework close. |
1720 | // All that needs to be done here is delete the Replaceable if the UText |
1721 | // owns it. This occurs if the UText was created by cloning. |
1722 | if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) { |
1723 | Replaceable *rep = (Replaceable *)ut->context; |
1724 | delete rep; |
1725 | ut->context = NULL; |
1726 | } |
1727 | } |
1728 | |
1729 | |
1730 | static int64_t U_CALLCONV |
1731 | repTextLength(UText *ut) { |
1732 | const Replaceable *replSrc = (const Replaceable *)ut->context; |
1733 | int32_t len = replSrc->length(); |
1734 | return len; |
1735 | } |
1736 | |
1737 | |
1738 | static UBool U_CALLCONV |
1739 | repTextAccess(UText *ut, int64_t index, UBool forward) { |
1740 | const Replaceable *rep=(const Replaceable *)ut->context; |
1741 | int32_t length=rep->length(); // Full length of the input text (bigger than a chunk) |
1742 | |
1743 | // clip the requested index to the limits of the text. |
1744 | int32_t index32 = pinIndex(index, length); |
1745 | U_ASSERT(index<=INT32_MAX); |
1746 | |
1747 | |
1748 | /* |
1749 | * Compute start/limit boundaries around index, for a segment of text |
1750 | * to be extracted. |
1751 | * To allow for the possibility that our user gave an index to the trailing |
1752 | * half of a surrogate pair, we must request one extra preceding UChar when |
1753 | * going in the forward direction. This will ensure that the buffer has the |
1754 | * entire code point at the specified index. |
1755 | */ |
1756 | if(forward) { |
1757 | |
1758 | if (index32>=ut->chunkNativeStart && index32<ut->chunkNativeLimit) { |
1759 | // Buffer already contains the requested position. |
1760 | ut->chunkOffset = (int32_t)(index - ut->chunkNativeStart); |
1761 | return TRUE; |
1762 | } |
1763 | if (index32>=length && ut->chunkNativeLimit==length) { |
1764 | // Request for end of string, and buffer already extends up to it. |
1765 | // Can't get the data, but don't change the buffer. |
1766 | ut->chunkOffset = length - (int32_t)ut->chunkNativeStart; |
1767 | return FALSE; |
1768 | } |
1769 | |
1770 | ut->chunkNativeLimit = index + REP_TEXT_CHUNK_SIZE - 1; |
1771 | // Going forward, so we want to have the buffer with stuff at and beyond |
1772 | // the requested index. The -1 gets us one code point before the |
1773 | // requested index also, to handle the case of the index being on |
1774 | // a trail surrogate of a surrogate pair. |
1775 | if(ut->chunkNativeLimit > length) { |
1776 | ut->chunkNativeLimit = length; |
1777 | } |
1778 | // unless buffer ran off end, start is index-1. |
1779 | ut->chunkNativeStart = ut->chunkNativeLimit - REP_TEXT_CHUNK_SIZE; |
1780 | if(ut->chunkNativeStart < 0) { |
1781 | ut->chunkNativeStart = 0; |
1782 | } |
1783 | } else { |
1784 | // Reverse iteration. Fill buffer with data preceding the requested index. |
1785 | if (index32>ut->chunkNativeStart && index32<=ut->chunkNativeLimit) { |
1786 | // Requested position already in buffer. |
1787 | ut->chunkOffset = index32 - (int32_t)ut->chunkNativeStart; |
1788 | return TRUE; |
1789 | } |
1790 | if (index32==0 && ut->chunkNativeStart==0) { |
1791 | // Request for start, buffer already begins at start. |
1792 | // No data, but keep the buffer as is. |
1793 | ut->chunkOffset = 0; |
1794 | return FALSE; |
1795 | } |
1796 | |
1797 | // Figure out the bounds of the chunk to extract for reverse iteration. |
1798 | // Need to worry about chunk not splitting surrogate pairs, and while still |
1799 | // containing the data we need. |
1800 | // Fix by requesting a chunk that includes an extra UChar at the end. |
1801 | // If this turns out to be a lead surrogate, we can lop it off and still have |
1802 | // the data we wanted. |
1803 | ut->chunkNativeStart = index32 + 1 - REP_TEXT_CHUNK_SIZE; |
1804 | if (ut->chunkNativeStart < 0) { |
1805 | ut->chunkNativeStart = 0; |
1806 | } |
1807 | |
1808 | ut->chunkNativeLimit = index32 + 1; |
1809 | if (ut->chunkNativeLimit > length) { |
1810 | ut->chunkNativeLimit = length; |
1811 | } |
1812 | } |
1813 | |
1814 | // Extract the new chunk of text from the Replaceable source. |
1815 | ReplExtra *ex = (ReplExtra *)ut->pExtra; |
1816 | // UnicodeString with its buffer a writable alias to the chunk buffer |
1817 | UnicodeString buffer(ex->s, 0 /*buffer length*/, REP_TEXT_CHUNK_SIZE /*buffer capacity*/); |
1818 | rep->extractBetween((int32_t)ut->chunkNativeStart, (int32_t)ut->chunkNativeLimit, buffer); |
1819 | |
1820 | ut->chunkContents = ex->s; |
1821 | ut->chunkLength = (int32_t)(ut->chunkNativeLimit - ut->chunkNativeStart); |
1822 | ut->chunkOffset = (int32_t)(index32 - ut->chunkNativeStart); |
1823 | |
1824 | // Surrogate pairs from the input text must not span chunk boundaries. |
1825 | // If end of chunk could be the start of a surrogate, trim it off. |
1826 | if (ut->chunkNativeLimit < length && |
1827 | U16_IS_LEAD(ex->s[ut->chunkLength-1])) { |
1828 | ut->chunkLength--; |
1829 | ut->chunkNativeLimit--; |
1830 | if (ut->chunkOffset > ut->chunkLength) { |
1831 | ut->chunkOffset = ut->chunkLength; |
1832 | } |
1833 | } |
1834 | |
1835 | // if the first UChar in the chunk could be the trailing half of a surrogate pair, |
1836 | // trim it off. |
1837 | if(ut->chunkNativeStart>0 && U16_IS_TRAIL(ex->s[0])) { |
1838 | ++(ut->chunkContents); |
1839 | ++(ut->chunkNativeStart); |
1840 | --(ut->chunkLength); |
1841 | --(ut->chunkOffset); |
1842 | } |
1843 | |
1844 | // adjust the index/chunkOffset to a code point boundary |
1845 | U16_SET_CP_START(ut->chunkContents, 0, ut->chunkOffset); |
1846 | |
1847 | // Use fast indexing for get/setNativeIndex() |
1848 | ut->nativeIndexingLimit = ut->chunkLength; |
1849 | |
1850 | return TRUE; |
1851 | } |
1852 | |
1853 | |
1854 | |
1855 | static int32_t U_CALLCONV |
1856 | (UText *ut, |
1857 | int64_t start, int64_t limit, |
1858 | UChar *dest, int32_t destCapacity, |
1859 | UErrorCode *status) { |
1860 | const Replaceable *rep=(const Replaceable *)ut->context; |
1861 | int32_t length=rep->length(); |
1862 | |
1863 | if(U_FAILURE(*status)) { |
1864 | return 0; |
1865 | } |
1866 | if(destCapacity<0 || (dest==NULL && destCapacity>0)) { |
1867 | *status=U_ILLEGAL_ARGUMENT_ERROR; |
1868 | } |
1869 | if(start>limit) { |
1870 | *status=U_INDEX_OUTOFBOUNDS_ERROR; |
1871 | return 0; |
1872 | } |
1873 | |
1874 | int32_t start32 = pinIndex(start, length); |
1875 | int32_t limit32 = pinIndex(limit, length); |
1876 | |
1877 | // adjust start, limit if they point to trail half of surrogates |
1878 | if (start32<length && U16_IS_TRAIL(rep->charAt(start32)) && |
1879 | U_IS_SUPPLEMENTARY(rep->char32At(start32))){ |
1880 | start32--; |
1881 | } |
1882 | if (limit32<length && U16_IS_TRAIL(rep->charAt(limit32)) && |
1883 | U_IS_SUPPLEMENTARY(rep->char32At(limit32))){ |
1884 | limit32--; |
1885 | } |
1886 | |
1887 | length=limit32-start32; |
1888 | if(length>destCapacity) { |
1889 | limit32 = start32 + destCapacity; |
1890 | } |
1891 | UnicodeString buffer(dest, 0, destCapacity); // writable alias |
1892 | rep->extractBetween(start32, limit32, buffer); |
1893 | repTextAccess(ut, limit32, TRUE); |
1894 | |
1895 | return u_terminateUChars(dest, destCapacity, length, status); |
1896 | } |
1897 | |
1898 | static int32_t U_CALLCONV |
1899 | repTextReplace(UText *ut, |
1900 | int64_t start, int64_t limit, |
1901 | const UChar *src, int32_t length, |
1902 | UErrorCode *status) { |
1903 | Replaceable *rep=(Replaceable *)ut->context; |
1904 | int32_t oldLength; |
1905 | |
1906 | if(U_FAILURE(*status)) { |
1907 | return 0; |
1908 | } |
1909 | if(src==NULL && length!=0) { |
1910 | *status=U_ILLEGAL_ARGUMENT_ERROR; |
1911 | return 0; |
1912 | } |
1913 | oldLength=rep->length(); // will subtract from new length |
1914 | if(start>limit ) { |
1915 | *status=U_INDEX_OUTOFBOUNDS_ERROR; |
1916 | return 0; |
1917 | } |
1918 | |
1919 | int32_t start32 = pinIndex(start, oldLength); |
1920 | int32_t limit32 = pinIndex(limit, oldLength); |
1921 | |
1922 | // Snap start & limit to code point boundaries. |
1923 | if (start32<oldLength && U16_IS_TRAIL(rep->charAt(start32)) && |
1924 | start32>0 && U16_IS_LEAD(rep->charAt(start32-1))) |
1925 | { |
1926 | start32--; |
1927 | } |
1928 | if (limit32<oldLength && U16_IS_LEAD(rep->charAt(limit32-1)) && |
1929 | U16_IS_TRAIL(rep->charAt(limit32))) |
1930 | { |
1931 | limit32++; |
1932 | } |
1933 | |
1934 | // Do the actual replace operation using methods of the Replaceable class |
1935 | UnicodeString replStr((UBool)(length<0), src, length); // read-only alias |
1936 | rep->handleReplaceBetween(start32, limit32, replStr); |
1937 | int32_t newLength = rep->length(); |
1938 | int32_t lengthDelta = newLength - oldLength; |
1939 | |
1940 | // Is the UText chunk buffer OK? |
1941 | if (ut->chunkNativeLimit > start32) { |
1942 | // this replace operation may have impacted the current chunk. |
1943 | // invalidate it, which will force a reload on the next access. |
1944 | invalidateChunk(ut); |
1945 | } |
1946 | |
1947 | // set the iteration position to the end of the newly inserted replacement text. |
1948 | int32_t newIndexPos = limit32 + lengthDelta; |
1949 | repTextAccess(ut, newIndexPos, TRUE); |
1950 | |
1951 | return lengthDelta; |
1952 | } |
1953 | |
1954 | |
1955 | static void U_CALLCONV |
1956 | repTextCopy(UText *ut, |
1957 | int64_t start, int64_t limit, |
1958 | int64_t destIndex, |
1959 | UBool move, |
1960 | UErrorCode *status) |
1961 | { |
1962 | Replaceable *rep=(Replaceable *)ut->context; |
1963 | int32_t length=rep->length(); |
1964 | |
1965 | if(U_FAILURE(*status)) { |
1966 | return; |
1967 | } |
1968 | if (start>limit || (start<destIndex && destIndex<limit)) |
1969 | { |
1970 | *status=U_INDEX_OUTOFBOUNDS_ERROR; |
1971 | return; |
1972 | } |
1973 | |
1974 | int32_t start32 = pinIndex(start, length); |
1975 | int32_t limit32 = pinIndex(limit, length); |
1976 | int32_t destIndex32 = pinIndex(destIndex, length); |
1977 | |
1978 | // TODO: snap input parameters to code point boundaries. |
1979 | |
1980 | if(move) { |
1981 | // move: copy to destIndex, then replace original with nothing |
1982 | int32_t segLength=limit32-start32; |
1983 | rep->copy(start32, limit32, destIndex32); |
1984 | if(destIndex32<start32) { |
1985 | start32+=segLength; |
1986 | limit32+=segLength; |
1987 | } |
1988 | rep->handleReplaceBetween(start32, limit32, UnicodeString()); |
1989 | } else { |
1990 | // copy |
1991 | rep->copy(start32, limit32, destIndex32); |
1992 | } |
1993 | |
1994 | // If the change to the text touched the region in the chunk buffer, |
1995 | // invalidate the buffer. |
1996 | int32_t firstAffectedIndex = destIndex32; |
1997 | if (move && start32<firstAffectedIndex) { |
1998 | firstAffectedIndex = start32; |
1999 | } |
2000 | if (firstAffectedIndex < ut->chunkNativeLimit) { |
2001 | // changes may have affected range covered by the chunk |
2002 | invalidateChunk(ut); |
2003 | } |
2004 | |
2005 | // Put iteration position at the newly inserted (moved) block, |
2006 | int32_t nativeIterIndex = destIndex32 + limit32 - start32; |
2007 | if (move && destIndex32>start32) { |
2008 | // moved a block of text towards the end of the string. |
2009 | nativeIterIndex = destIndex32; |
2010 | } |
2011 | |
2012 | // Set position, reload chunk if needed. |
2013 | repTextAccess(ut, nativeIterIndex, TRUE); |
2014 | } |
2015 | |
2016 | static const struct UTextFuncs repFuncs = |
2017 | { |
2018 | sizeof(UTextFuncs), |
2019 | 0, 0, 0, // Reserved alignment padding |
2020 | repTextClone, |
2021 | repTextLength, |
2022 | repTextAccess, |
2023 | repTextExtract, |
2024 | repTextReplace, |
2025 | repTextCopy, |
2026 | NULL, // MapOffsetToNative, |
2027 | NULL, // MapIndexToUTF16, |
2028 | repTextClose, |
2029 | NULL, // spare 1 |
2030 | NULL, // spare 2 |
2031 | NULL // spare 3 |
2032 | }; |
2033 | |
2034 | |
2035 | U_CAPI UText * U_EXPORT2 |
2036 | utext_openReplaceable(UText *ut, Replaceable *rep, UErrorCode *status) |
2037 | { |
2038 | if(U_FAILURE(*status)) { |
2039 | return NULL; |
2040 | } |
2041 | if(rep==NULL) { |
2042 | *status=U_ILLEGAL_ARGUMENT_ERROR; |
2043 | return NULL; |
2044 | } |
2045 | ut = utext_setup(ut, sizeof(ReplExtra), status); |
2046 | if(U_FAILURE(*status)) { |
2047 | return ut; |
2048 | } |
2049 | |
2050 | ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_WRITABLE); |
2051 | if(rep->hasMetaData()) { |
2052 | ut->providerProperties |=I32_FLAG(UTEXT_PROVIDER_HAS_META_DATA); |
2053 | } |
2054 | |
2055 | ut->pFuncs = &repFuncs; |
2056 | ut->context = rep; |
2057 | return ut; |
2058 | } |
2059 | |
2060 | U_CDECL_END |
2061 | |
2062 | |
2063 | |
2064 | |
2065 | |
2066 | |
2067 | |
2068 | |
2069 | //------------------------------------------------------------------------------ |
2070 | // |
2071 | // UText implementation for UnicodeString (read/write) and |
2072 | // for const UnicodeString (read only) |
2073 | // (same implementation, only the flags are different) |
2074 | // |
2075 | // Use of UText data members: |
2076 | // context pointer to UnicodeString |
2077 | // p pointer to UnicodeString IF this UText owns the string |
2078 | // and it must be deleted on close(). NULL otherwise. |
2079 | // |
2080 | //------------------------------------------------------------------------------ |
2081 | |
2082 | U_CDECL_BEGIN |
2083 | |
2084 | |
2085 | static UText * U_CALLCONV |
2086 | unistrTextClone(UText *dest, const UText *src, UBool deep, UErrorCode *status) { |
2087 | // First do a generic shallow clone. Does everything needed for the UText struct itself. |
2088 | dest = shallowTextClone(dest, src, status); |
2089 | |
2090 | // For deep clones, make a copy of the UnicodeSring. |
2091 | // The copied UnicodeString storage is owned by the newly created UText clone. |
2092 | // A non-NULL pointer in UText.p is the signal to the close() function to delete |
2093 | // the UText. |
2094 | // |
2095 | if (deep && U_SUCCESS(*status)) { |
2096 | const UnicodeString *srcString = (const UnicodeString *)src->context; |
2097 | dest->context = new UnicodeString(*srcString); |
2098 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT); |
2099 | |
2100 | // with deep clone, the copy is writable, even when the source is not. |
2101 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_WRITABLE); |
2102 | } |
2103 | return dest; |
2104 | } |
2105 | |
2106 | static void U_CALLCONV |
2107 | unistrTextClose(UText *ut) { |
2108 | // Most of the work of close is done by the generic UText framework close. |
2109 | // All that needs to be done here is delete the UnicodeString if the UText |
2110 | // owns it. This occurs if the UText was created by cloning. |
2111 | if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) { |
2112 | UnicodeString *str = (UnicodeString *)ut->context; |
2113 | delete str; |
2114 | ut->context = NULL; |
2115 | } |
2116 | } |
2117 | |
2118 | |
2119 | static int64_t U_CALLCONV |
2120 | unistrTextLength(UText *t) { |
2121 | return ((const UnicodeString *)t->context)->length(); |
2122 | } |
2123 | |
2124 | |
2125 | static UBool U_CALLCONV |
2126 | unistrTextAccess(UText *ut, int64_t index, UBool forward) { |
2127 | int32_t length = ut->chunkLength; |
2128 | ut->chunkOffset = pinIndex(index, length); |
2129 | |
2130 | // Check whether request is at the start or end |
2131 | UBool retVal = (forward && index<length) || (!forward && index>0); |
2132 | return retVal; |
2133 | } |
2134 | |
2135 | |
2136 | |
2137 | static int32_t U_CALLCONV |
2138 | (UText *t, |
2139 | int64_t start, int64_t limit, |
2140 | UChar *dest, int32_t destCapacity, |
2141 | UErrorCode *pErrorCode) { |
2142 | const UnicodeString *us=(const UnicodeString *)t->context; |
2143 | int32_t length=us->length(); |
2144 | |
2145 | if(U_FAILURE(*pErrorCode)) { |
2146 | return 0; |
2147 | } |
2148 | if(destCapacity<0 || (dest==NULL && destCapacity>0)) { |
2149 | *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
2150 | } |
2151 | if(start<0 || start>limit) { |
2152 | *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
2153 | return 0; |
2154 | } |
2155 | |
2156 | int32_t start32 = start<length ? us->getChar32Start((int32_t)start) : length; |
2157 | int32_t limit32 = limit<length ? us->getChar32Start((int32_t)limit) : length; |
2158 | |
2159 | length=limit32-start32; |
2160 | if (destCapacity>0 && dest!=NULL) { |
2161 | int32_t trimmedLength = length; |
2162 | if(trimmedLength>destCapacity) { |
2163 | trimmedLength=destCapacity; |
2164 | } |
2165 | us->extract(start32, trimmedLength, dest); |
2166 | t->chunkOffset = start32+trimmedLength; |
2167 | } else { |
2168 | t->chunkOffset = start32; |
2169 | } |
2170 | u_terminateUChars(dest, destCapacity, length, pErrorCode); |
2171 | return length; |
2172 | } |
2173 | |
2174 | static int32_t U_CALLCONV |
2175 | unistrTextReplace(UText *ut, |
2176 | int64_t start, int64_t limit, |
2177 | const UChar *src, int32_t length, |
2178 | UErrorCode *pErrorCode) { |
2179 | UnicodeString *us=(UnicodeString *)ut->context; |
2180 | int32_t oldLength; |
2181 | |
2182 | if(U_FAILURE(*pErrorCode)) { |
2183 | return 0; |
2184 | } |
2185 | if(src==NULL && length!=0) { |
2186 | *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
2187 | } |
2188 | if(start>limit) { |
2189 | *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
2190 | return 0; |
2191 | } |
2192 | oldLength=us->length(); |
2193 | int32_t start32 = pinIndex(start, oldLength); |
2194 | int32_t limit32 = pinIndex(limit, oldLength); |
2195 | if (start32 < oldLength) { |
2196 | start32 = us->getChar32Start(start32); |
2197 | } |
2198 | if (limit32 < oldLength) { |
2199 | limit32 = us->getChar32Start(limit32); |
2200 | } |
2201 | |
2202 | // replace |
2203 | us->replace(start32, limit32-start32, src, length); |
2204 | int32_t newLength = us->length(); |
2205 | |
2206 | // Update the chunk description. |
2207 | ut->chunkContents = us->getBuffer(); |
2208 | ut->chunkLength = newLength; |
2209 | ut->chunkNativeLimit = newLength; |
2210 | ut->nativeIndexingLimit = newLength; |
2211 | |
2212 | // Set iteration position to the point just following the newly inserted text. |
2213 | int32_t lengthDelta = newLength - oldLength; |
2214 | ut->chunkOffset = limit32 + lengthDelta; |
2215 | |
2216 | return lengthDelta; |
2217 | } |
2218 | |
2219 | static void U_CALLCONV |
2220 | unistrTextCopy(UText *ut, |
2221 | int64_t start, int64_t limit, |
2222 | int64_t destIndex, |
2223 | UBool move, |
2224 | UErrorCode *pErrorCode) { |
2225 | UnicodeString *us=(UnicodeString *)ut->context; |
2226 | int32_t length=us->length(); |
2227 | |
2228 | if(U_FAILURE(*pErrorCode)) { |
2229 | return; |
2230 | } |
2231 | int32_t start32 = pinIndex(start, length); |
2232 | int32_t limit32 = pinIndex(limit, length); |
2233 | int32_t destIndex32 = pinIndex(destIndex, length); |
2234 | |
2235 | if( start32>limit32 || (start32<destIndex32 && destIndex32<limit32)) { |
2236 | *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR; |
2237 | return; |
2238 | } |
2239 | |
2240 | if(move) { |
2241 | // move: copy to destIndex, then remove original |
2242 | int32_t segLength=limit32-start32; |
2243 | us->copy(start32, limit32, destIndex32); |
2244 | if(destIndex32<start32) { |
2245 | start32+=segLength; |
2246 | } |
2247 | us->remove(start32, segLength); |
2248 | } else { |
2249 | // copy |
2250 | us->copy(start32, limit32, destIndex32); |
2251 | } |
2252 | |
2253 | // update chunk description, set iteration position. |
2254 | ut->chunkContents = us->getBuffer(); |
2255 | if (move==FALSE) { |
2256 | // copy operation, string length grows |
2257 | ut->chunkLength += limit32-start32; |
2258 | ut->chunkNativeLimit = ut->chunkLength; |
2259 | ut->nativeIndexingLimit = ut->chunkLength; |
2260 | } |
2261 | |
2262 | // Iteration position to end of the newly inserted text. |
2263 | ut->chunkOffset = destIndex32+limit32-start32; |
2264 | if (move && destIndex32>start32) { |
2265 | ut->chunkOffset = destIndex32; |
2266 | } |
2267 | |
2268 | } |
2269 | |
2270 | static const struct UTextFuncs unistrFuncs = |
2271 | { |
2272 | sizeof(UTextFuncs), |
2273 | 0, 0, 0, // Reserved alignment padding |
2274 | unistrTextClone, |
2275 | unistrTextLength, |
2276 | unistrTextAccess, |
2277 | unistrTextExtract, |
2278 | unistrTextReplace, |
2279 | unistrTextCopy, |
2280 | NULL, // MapOffsetToNative, |
2281 | NULL, // MapIndexToUTF16, |
2282 | unistrTextClose, |
2283 | NULL, // spare 1 |
2284 | NULL, // spare 2 |
2285 | NULL // spare 3 |
2286 | }; |
2287 | |
2288 | |
2289 | |
2290 | U_CDECL_END |
2291 | |
2292 | |
2293 | U_CAPI UText * U_EXPORT2 |
2294 | utext_openUnicodeString(UText *ut, UnicodeString *s, UErrorCode *status) { |
2295 | ut = utext_openConstUnicodeString(ut, s, status); |
2296 | if (U_SUCCESS(*status)) { |
2297 | ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_WRITABLE); |
2298 | } |
2299 | return ut; |
2300 | } |
2301 | |
2302 | |
2303 | |
2304 | U_CAPI UText * U_EXPORT2 |
2305 | utext_openConstUnicodeString(UText *ut, const UnicodeString *s, UErrorCode *status) { |
2306 | if (U_SUCCESS(*status) && s->isBogus()) { |
2307 | // The UnicodeString is bogus, but we still need to detach the UText |
2308 | // from whatever it was hooked to before, if anything. |
2309 | utext_openUChars(ut, NULL, 0, status); |
2310 | *status = U_ILLEGAL_ARGUMENT_ERROR; |
2311 | return ut; |
2312 | } |
2313 | ut = utext_setup(ut, 0, status); |
2314 | // note: use the standard (writable) function table for UnicodeString. |
2315 | // The flag settings disable writing, so having the functions in |
2316 | // the table is harmless. |
2317 | if (U_SUCCESS(*status)) { |
2318 | ut->pFuncs = &unistrFuncs; |
2319 | ut->context = s; |
2320 | ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS); |
2321 | ut->chunkContents = s->getBuffer(); |
2322 | ut->chunkLength = s->length(); |
2323 | ut->chunkNativeStart = 0; |
2324 | ut->chunkNativeLimit = ut->chunkLength; |
2325 | ut->nativeIndexingLimit = ut->chunkLength; |
2326 | } |
2327 | return ut; |
2328 | } |
2329 | |
2330 | //------------------------------------------------------------------------------ |
2331 | // |
2332 | // UText implementation for const UChar * strings |
2333 | // |
2334 | // Use of UText data members: |
2335 | // context pointer to UnicodeString |
2336 | // a length. -1 if not yet known. |
2337 | // |
2338 | // TODO: support 64 bit lengths. |
2339 | // |
2340 | //------------------------------------------------------------------------------ |
2341 | |
2342 | U_CDECL_BEGIN |
2343 | |
2344 | |
2345 | static UText * U_CALLCONV |
2346 | ucstrTextClone(UText *dest, const UText * src, UBool deep, UErrorCode * status) { |
2347 | // First do a generic shallow clone. |
2348 | dest = shallowTextClone(dest, src, status); |
2349 | |
2350 | // For deep clones, make a copy of the string. |
2351 | // The copied storage is owned by the newly created clone. |
2352 | // A non-NULL pointer in UText.p is the signal to the close() function to delete |
2353 | // it. |
2354 | // |
2355 | if (deep && U_SUCCESS(*status)) { |
2356 | U_ASSERT(utext_nativeLength(dest) < INT32_MAX); |
2357 | int32_t len = (int32_t)utext_nativeLength(dest); |
2358 | |
2359 | // The cloned string IS going to be NUL terminated, whether or not the original was. |
2360 | const UChar *srcStr = (const UChar *)src->context; |
2361 | UChar *copyStr = (UChar *)uprv_malloc((len+1) * sizeof(UChar)); |
2362 | if (copyStr == NULL) { |
2363 | *status = U_MEMORY_ALLOCATION_ERROR; |
2364 | } else { |
2365 | int64_t i; |
2366 | for (i=0; i<len; i++) { |
2367 | copyStr[i] = srcStr[i]; |
2368 | } |
2369 | copyStr[len] = 0; |
2370 | dest->context = copyStr; |
2371 | dest->providerProperties |= I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT); |
2372 | } |
2373 | } |
2374 | return dest; |
2375 | } |
2376 | |
2377 | |
2378 | static void U_CALLCONV |
2379 | ucstrTextClose(UText *ut) { |
2380 | // Most of the work of close is done by the generic UText framework close. |
2381 | // All that needs to be done here is delete the string if the UText |
2382 | // owns it. This occurs if the UText was created by cloning. |
2383 | if (ut->providerProperties & I32_FLAG(UTEXT_PROVIDER_OWNS_TEXT)) { |
2384 | UChar *s = (UChar *)ut->context; |
2385 | uprv_free(s); |
2386 | ut->context = NULL; |
2387 | } |
2388 | } |
2389 | |
2390 | |
2391 | |
2392 | static int64_t U_CALLCONV |
2393 | ucstrTextLength(UText *ut) { |
2394 | if (ut->a < 0) { |
2395 | // null terminated, we don't yet know the length. Scan for it. |
2396 | // Access is not convenient for doing this |
2397 | // because the current interation postion can't be changed. |
2398 | const UChar *str = (const UChar *)ut->context; |
2399 | for (;;) { |
2400 | if (str[ut->chunkNativeLimit] == 0) { |
2401 | break; |
2402 | } |
2403 | ut->chunkNativeLimit++; |
2404 | } |
2405 | ut->a = ut->chunkNativeLimit; |
2406 | ut->chunkLength = (int32_t)ut->chunkNativeLimit; |
2407 | ut->nativeIndexingLimit = ut->chunkLength; |
2408 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
2409 | } |
2410 | return ut->a; |
2411 | } |
2412 | |
2413 | |
2414 | static UBool U_CALLCONV |
2415 | ucstrTextAccess(UText *ut, int64_t index, UBool forward) { |
2416 | const UChar *str = (const UChar *)ut->context; |
2417 | |
2418 | // pin the requested index to the bounds of the string, |
2419 | // and set current iteration position. |
2420 | if (index<0) { |
2421 | index = 0; |
2422 | } else if (index < ut->chunkNativeLimit) { |
2423 | // The request data is within the chunk as it is known so far. |
2424 | // Put index on a code point boundary. |
2425 | U16_SET_CP_START(str, 0, index); |
2426 | } else if (ut->a >= 0) { |
2427 | // We know the length of this string, and the user is requesting something |
2428 | // at or beyond the length. Pin the requested index to the length. |
2429 | index = ut->a; |
2430 | } else { |
2431 | // Null terminated string, length not yet known, and the requested index |
2432 | // is beyond where we have scanned so far. |
2433 | // Scan to 32 UChars beyond the requested index. The strategy here is |
2434 | // to avoid fully scanning a long string when the caller only wants to |
2435 | // see a few characters at its beginning. |
2436 | int32_t scanLimit = (int32_t)index + 32; |
2437 | if ((index + 32)>INT32_MAX || (index + 32)<0 ) { // note: int64 expression |
2438 | scanLimit = INT32_MAX; |
2439 | } |
2440 | |
2441 | int32_t chunkLimit = (int32_t)ut->chunkNativeLimit; |
2442 | for (; chunkLimit<scanLimit; chunkLimit++) { |
2443 | if (str[chunkLimit] == 0) { |
2444 | // We found the end of the string. Remember it, pin the requested index to it, |
2445 | // and bail out of here. |
2446 | ut->a = chunkLimit; |
2447 | ut->chunkLength = chunkLimit; |
2448 | ut->nativeIndexingLimit = chunkLimit; |
2449 | if (index >= chunkLimit) { |
2450 | index = chunkLimit; |
2451 | } else { |
2452 | U16_SET_CP_START(str, 0, index); |
2453 | } |
2454 | |
2455 | ut->chunkNativeLimit = chunkLimit; |
2456 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
2457 | goto breakout; |
2458 | } |
2459 | } |
2460 | // We scanned through the next batch of UChars without finding the end. |
2461 | U16_SET_CP_START(str, 0, index); |
2462 | if (chunkLimit == INT32_MAX) { |
2463 | // Scanned to the limit of a 32 bit length. |
2464 | // Forceably trim the overlength string back so length fits in int32 |
2465 | // TODO: add support for 64 bit strings. |
2466 | ut->a = chunkLimit; |
2467 | ut->chunkLength = chunkLimit; |
2468 | ut->nativeIndexingLimit = chunkLimit; |
2469 | if (index > chunkLimit) { |
2470 | index = chunkLimit; |
2471 | } |
2472 | ut->chunkNativeLimit = chunkLimit; |
2473 | ut->providerProperties &= ~I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
2474 | } else { |
2475 | // The endpoint of a chunk must not be left in the middle of a surrogate pair. |
2476 | // If the current end is on a lead surrogate, back the end up by one. |
2477 | // It doesn't matter if the end char happens to be an unpaired surrogate, |
2478 | // and it's simpler not to worry about it. |
2479 | if (U16_IS_LEAD(str[chunkLimit-1])) { |
2480 | --chunkLimit; |
2481 | } |
2482 | // Null-terminated chunk with end still unknown. |
2483 | // Update the chunk length to reflect what has been scanned thus far. |
2484 | // That the full length is still unknown is (still) flagged by |
2485 | // ut->a being < 0. |
2486 | ut->chunkNativeLimit = chunkLimit; |
2487 | ut->nativeIndexingLimit = chunkLimit; |
2488 | ut->chunkLength = chunkLimit; |
2489 | } |
2490 | |
2491 | } |
2492 | breakout: |
2493 | U_ASSERT(index<=INT32_MAX); |
2494 | ut->chunkOffset = (int32_t)index; |
2495 | |
2496 | // Check whether request is at the start or end |
2497 | UBool retVal = (forward && index<ut->chunkNativeLimit) || (!forward && index>0); |
2498 | return retVal; |
2499 | } |
2500 | |
2501 | |
2502 | |
2503 | static int32_t U_CALLCONV |
2504 | (UText *ut, |
2505 | int64_t start, int64_t limit, |
2506 | UChar *dest, int32_t destCapacity, |
2507 | UErrorCode *pErrorCode) |
2508 | { |
2509 | if(U_FAILURE(*pErrorCode)) { |
2510 | return 0; |
2511 | } |
2512 | if(destCapacity<0 || (dest==NULL && destCapacity>0) || start>limit) { |
2513 | *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR; |
2514 | return 0; |
2515 | } |
2516 | |
2517 | //const UChar *s=(const UChar *)ut->context; |
2518 | int32_t si, di; |
2519 | |
2520 | int32_t start32; |
2521 | int32_t limit32; |
2522 | |
2523 | // Access the start. Does two things we need: |
2524 | // Pins 'start' to the length of the string, if it came in out-of-bounds. |
2525 | // Snaps 'start' to the beginning of a code point. |
2526 | ucstrTextAccess(ut, start, TRUE); |
2527 | const UChar *s=ut->chunkContents; |
2528 | start32 = ut->chunkOffset; |
2529 | |
2530 | int32_t strLength=(int32_t)ut->a; |
2531 | if (strLength >= 0) { |
2532 | limit32 = pinIndex(limit, strLength); |
2533 | } else { |
2534 | limit32 = pinIndex(limit, INT32_MAX); |
2535 | } |
2536 | di = 0; |
2537 | for (si=start32; si<limit32; si++) { |
2538 | if (strLength<0 && s[si]==0) { |
2539 | // Just hit the end of a null-terminated string. |
2540 | ut->a = si; // set string length for this UText |
2541 | ut->chunkNativeLimit = si; |
2542 | ut->chunkLength = si; |
2543 | ut->nativeIndexingLimit = si; |
2544 | strLength = si; |
2545 | limit32 = si; |
2546 | break; |
2547 | } |
2548 | U_ASSERT(di>=0); /* to ensure di never exceeds INT32_MAX, which must not happen logically */ |
2549 | if (di<destCapacity) { |
2550 | // only store if there is space. |
2551 | dest[di] = s[si]; |
2552 | } else { |
2553 | if (strLength>=0) { |
2554 | // We have filled the destination buffer, and the string length is known. |
2555 | // Cut the loop short. There is no need to scan string termination. |
2556 | di = limit32 - start32; |
2557 | si = limit32; |
2558 | break; |
2559 | } |
2560 | } |
2561 | di++; |
2562 | } |
2563 | |
2564 | // If the limit index points to a lead surrogate of a pair, |
2565 | // add the corresponding trail surrogate to the destination. |
2566 | if (si>0 && U16_IS_LEAD(s[si-1]) && |
2567 | ((si<strLength || strLength<0) && U16_IS_TRAIL(s[si]))) |
2568 | { |
2569 | if (di<destCapacity) { |
2570 | // store only if there is space in the output buffer. |
2571 | dest[di++] = s[si]; |
2572 | } |
2573 | si++; |
2574 | } |
2575 | |
2576 | // Put iteration position at the point just following the extracted text |
2577 | if (si <= ut->chunkNativeLimit) { |
2578 | ut->chunkOffset = si; |
2579 | } else { |
2580 | ucstrTextAccess(ut, si, TRUE); |
2581 | } |
2582 | |
2583 | // Add a terminating NUL if space in the buffer permits, |
2584 | // and set the error status as required. |
2585 | u_terminateUChars(dest, destCapacity, di, pErrorCode); |
2586 | return di; |
2587 | } |
2588 | |
2589 | static const struct UTextFuncs ucstrFuncs = |
2590 | { |
2591 | sizeof(UTextFuncs), |
2592 | 0, 0, 0, // Reserved alignment padding |
2593 | ucstrTextClone, |
2594 | ucstrTextLength, |
2595 | ucstrTextAccess, |
2596 | ucstrTextExtract, |
2597 | NULL, // Replace |
2598 | NULL, // Copy |
2599 | NULL, // MapOffsetToNative, |
2600 | NULL, // MapIndexToUTF16, |
2601 | ucstrTextClose, |
2602 | NULL, // spare 1 |
2603 | NULL, // spare 2 |
2604 | NULL, // spare 3 |
2605 | }; |
2606 | |
2607 | U_CDECL_END |
2608 | |
2609 | static const UChar gEmptyUString[] = {0}; |
2610 | |
2611 | U_CAPI UText * U_EXPORT2 |
2612 | utext_openUChars(UText *ut, const UChar *s, int64_t length, UErrorCode *status) { |
2613 | if (U_FAILURE(*status)) { |
2614 | return NULL; |
2615 | } |
2616 | if(s==NULL && length==0) { |
2617 | s = gEmptyUString; |
2618 | } |
2619 | if (s==NULL || length < -1 || length>INT32_MAX) { |
2620 | *status = U_ILLEGAL_ARGUMENT_ERROR; |
2621 | return NULL; |
2622 | } |
2623 | ut = utext_setup(ut, 0, status); |
2624 | if (U_SUCCESS(*status)) { |
2625 | ut->pFuncs = &ucstrFuncs; |
2626 | ut->context = s; |
2627 | ut->providerProperties = I32_FLAG(UTEXT_PROVIDER_STABLE_CHUNKS); |
2628 | if (length==-1) { |
2629 | ut->providerProperties |= I32_FLAG(UTEXT_PROVIDER_LENGTH_IS_EXPENSIVE); |
2630 | } |
2631 | ut->a = length; |
2632 | ut->chunkContents = s; |
2633 | ut->chunkNativeStart = 0; |
2634 | ut->chunkNativeLimit = length>=0? length : 0; |
2635 | ut->chunkLength = (int32_t)ut->chunkNativeLimit; |
2636 | ut->chunkOffset = 0; |
2637 | ut->nativeIndexingLimit = ut->chunkLength; |
2638 | } |
2639 | return ut; |
2640 | } |
2641 | |
2642 | |
2643 | //------------------------------------------------------------------------------ |
2644 | // |
2645 | // UText implementation for text from ICU CharacterIterators |
2646 | // |
2647 | // Use of UText data members: |
2648 | // context pointer to the CharacterIterator |
2649 | // a length of the full text. |
2650 | // p pointer to buffer 1 |
2651 | // b start index of local buffer 1 contents |
2652 | // q pointer to buffer 2 |
2653 | // c start index of local buffer 2 contents |
2654 | // r pointer to the character iterator if the UText owns it. |
2655 | // Null otherwise. |
2656 | // |
2657 | //------------------------------------------------------------------------------ |
2658 | #define CIBufSize 16 |
2659 | |
2660 | U_CDECL_BEGIN |
2661 | static void U_CALLCONV |
2662 | charIterTextClose(UText *ut) { |
2663 | // Most of the work of close is done by the generic UText framework close. |
2664 | // All that needs to be done here is delete the CharacterIterator if the UText |
2665 | // owns it. This occurs if the UText was created by cloning. |
2666 | CharacterIterator *ci = (CharacterIterator *)ut->r; |
2667 | delete ci; |
2668 | ut->r = NULL; |
2669 | } |
2670 | |
2671 | static int64_t U_CALLCONV |
2672 | charIterTextLength(UText *ut) { |
2673 | return (int32_t)ut->a; |
2674 | } |
2675 | |
2676 | static UBool U_CALLCONV |
2677 | charIterTextAccess(UText *ut, int64_t index, UBool forward) { |
2678 | CharacterIterator *ci = (CharacterIterator *)ut->context; |
2679 | |
2680 | int32_t clippedIndex = (int32_t)index; |
2681 | if (clippedIndex<0) { |
2682 | clippedIndex=0; |
2683 | } else if (clippedIndex>=ut->a) { |
2684 | clippedIndex=(int32_t)ut->a; |
2685 | } |
2686 | int32_t neededIndex = clippedIndex; |
2687 | if (!forward && neededIndex>0) { |
2688 | // reverse iteration, want the position just before what was asked for. |
2689 | neededIndex--; |
2690 | } else if (forward && neededIndex==ut->a && neededIndex>0) { |
2691 | // Forward iteration, don't ask for something past the end of the text. |
2692 | neededIndex--; |
2693 | } |
2694 | |
2695 | // Find the native index of the start of the buffer containing what we want. |
2696 | neededIndex -= neededIndex % CIBufSize; |
2697 | |
2698 | UChar *buf = NULL; |
2699 | UBool needChunkSetup = TRUE; |
2700 | int i; |
2701 | if (ut->chunkNativeStart == neededIndex) { |
2702 | // The buffer we want is already the current chunk. |
2703 | needChunkSetup = FALSE; |
2704 | } else if (ut->b == neededIndex) { |
2705 | // The first buffer (buffer p) has what we need. |
2706 | buf = (UChar *)ut->p; |
2707 | } else if (ut->c == neededIndex) { |
2708 | // The second buffer (buffer q) has what we need. |
2709 | buf = (UChar *)ut->q; |
2710 | } else { |
2711 | // Neither buffer already has what we need. |
2712 | // Load new data from the character iterator. |
2713 | // Use the buf that is not the current buffer. |
2714 | buf = (UChar *)ut->p; |
2715 | if (ut->p == ut->chunkContents) { |
2716 | buf = (UChar *)ut->q; |
2717 | } |
2718 | ci->setIndex(neededIndex); |
2719 | for (i=0; i<CIBufSize; i++) { |
2720 | buf[i] = ci->nextPostInc(); |
2721 | if (i+neededIndex > ut->a) { |
2722 | break; |
2723 | } |
2724 | } |
2725 | } |
2726 | |
2727 | // We have a buffer with the data we need. |
2728 | // Set it up as the current chunk, if it wasn't already. |
2729 | if (needChunkSetup) { |
2730 | ut->chunkContents = buf; |
2731 | ut->chunkLength = CIBufSize; |
2732 | ut->chunkNativeStart = neededIndex; |
2733 | ut->chunkNativeLimit = neededIndex + CIBufSize; |
2734 | if (ut->chunkNativeLimit > ut->a) { |
2735 | ut->chunkNativeLimit = ut->a; |
2736 | ut->chunkLength = (int32_t)(ut->chunkNativeLimit)-(int32_t)(ut->chunkNativeStart); |
2737 | } |
2738 | ut->nativeIndexingLimit = ut->chunkLength; |
2739 | U_ASSERT(ut->chunkOffset>=0 && ut->chunkOffset<=CIBufSize); |
2740 | } |
2741 | ut->chunkOffset = clippedIndex - (int32_t)ut->chunkNativeStart; |
2742 | UBool success = (forward? ut->chunkOffset<ut->chunkLength : ut->chunkOffset>0); |
2743 | return success; |
2744 | } |
2745 | |
2746 | static UText * U_CALLCONV |
2747 | charIterTextClone(UText *dest, const UText *src, UBool deep, UErrorCode * status) { |
2748 | if (U_FAILURE(*status)) { |
2749 | return NULL; |
2750 | } |
2751 | |
2752 | if (deep) { |
2753 | // There is no CharacterIterator API for cloning the underlying text storage. |
2754 | *status = U_UNSUPPORTED_ERROR; |
2755 | return NULL; |
2756 | } else { |
2757 | CharacterIterator *srcCI =(CharacterIterator *)src->context; |
2758 | srcCI = srcCI->clone(); |
2759 | dest = utext_openCharacterIterator(dest, srcCI, status); |
2760 | if (U_FAILURE(*status)) { |
2761 | return dest; |
2762 | } |
2763 | // cast off const on getNativeIndex. |
2764 | // For CharacterIterator based UTexts, this is safe, the operation is const. |
2765 | int64_t ix = utext_getNativeIndex((UText *)src); |
2766 | utext_setNativeIndex(dest, ix); |
2767 | dest->r = srcCI; // flags that this UText owns the CharacterIterator |
2768 | } |
2769 | return dest; |
2770 | } |
2771 | |
2772 | static int32_t U_CALLCONV |
2773 | (UText *ut, |
2774 | int64_t start, int64_t limit, |
2775 | UChar *dest, int32_t destCapacity, |
2776 | UErrorCode *status) |
2777 | { |
2778 | if(U_FAILURE(*status)) { |
2779 | return 0; |
2780 | } |
2781 | if(destCapacity<0 || (dest==NULL && destCapacity>0) || start>limit) { |
2782 | *status=U_ILLEGAL_ARGUMENT_ERROR; |
2783 | return 0; |
2784 | } |
2785 | int32_t length = (int32_t)ut->a; |
2786 | int32_t start32 = pinIndex(start, length); |
2787 | int32_t limit32 = pinIndex(limit, length); |
2788 | int32_t desti = 0; |
2789 | int32_t srci; |
2790 | int32_t copyLimit; |
2791 | |
2792 | CharacterIterator *ci = (CharacterIterator *)ut->context; |
2793 | ci->setIndex32(start32); // Moves ix to lead of surrogate pair, if needed. |
2794 | srci = ci->getIndex(); |
2795 | copyLimit = srci; |
2796 | while (srci<limit32) { |
2797 | UChar32 c = ci->next32PostInc(); |
2798 | int32_t len = U16_LENGTH(c); |
2799 | U_ASSERT(desti+len>0); /* to ensure desti+len never exceeds MAX_INT32, which must not happen logically */ |
2800 | if (desti+len <= destCapacity) { |
2801 | U16_APPEND_UNSAFE(dest, desti, c); |
2802 | copyLimit = srci+len; |
2803 | } else { |
2804 | desti += len; |
2805 | *status = U_BUFFER_OVERFLOW_ERROR; |
2806 | } |
2807 | srci += len; |
2808 | } |
2809 | |
2810 | charIterTextAccess(ut, copyLimit, TRUE); |
2811 | |
2812 | u_terminateUChars(dest, destCapacity, desti, status); |
2813 | return desti; |
2814 | } |
2815 | |
2816 | static const struct UTextFuncs charIterFuncs = |
2817 | { |
2818 | sizeof(UTextFuncs), |
2819 | 0, 0, 0, // Reserved alignment padding |
2820 | charIterTextClone, |
2821 | charIterTextLength, |
2822 | charIterTextAccess, |
2823 | charIterTextExtract, |
2824 | NULL, // Replace |
2825 | NULL, // Copy |
2826 | NULL, // MapOffsetToNative, |
2827 | NULL, // MapIndexToUTF16, |
2828 | charIterTextClose, |
2829 | NULL, // spare 1 |
2830 | NULL, // spare 2 |
2831 | NULL // spare 3 |
2832 | }; |
2833 | U_CDECL_END |
2834 | |
2835 | |
2836 | U_CAPI UText * U_EXPORT2 |
2837 | utext_openCharacterIterator(UText *ut, CharacterIterator *ci, UErrorCode *status) { |
2838 | if (U_FAILURE(*status)) { |
2839 | return NULL; |
2840 | } |
2841 | |
2842 | if (ci->startIndex() > 0) { |
2843 | // No support for CharacterIterators that do not start indexing from zero. |
2844 | *status = U_UNSUPPORTED_ERROR; |
2845 | return NULL; |
2846 | } |
2847 | |
2848 | // Extra space in UText for 2 buffers of CIBufSize UChars each. |
2849 | int32_t = 2 * CIBufSize * sizeof(UChar); |
2850 | ut = utext_setup(ut, extraSpace, status); |
2851 | if (U_SUCCESS(*status)) { |
2852 | ut->pFuncs = &charIterFuncs; |
2853 | ut->context = ci; |
2854 | ut->providerProperties = 0; |
2855 | ut->a = ci->endIndex(); // Length of text |
2856 | ut->p = ut->pExtra; // First buffer |
2857 | ut->b = -1; // Native index of first buffer contents |
2858 | ut->q = (UChar*)ut->pExtra+CIBufSize; // Second buffer |
2859 | ut->c = -1; // Native index of second buffer contents |
2860 | |
2861 | // Initialize current chunk contents to be empty. |
2862 | // First access will fault something in. |
2863 | // Note: The initial nativeStart and chunkOffset must sum to zero |
2864 | // so that getNativeIndex() will correctly compute to zero |
2865 | // if no call to Access() has ever been made. They can't be both |
2866 | // zero without Access() thinking that the chunk is valid. |
2867 | ut->chunkContents = (UChar *)ut->p; |
2868 | ut->chunkNativeStart = -1; |
2869 | ut->chunkOffset = 1; |
2870 | ut->chunkNativeLimit = 0; |
2871 | ut->chunkLength = 0; |
2872 | ut->nativeIndexingLimit = ut->chunkOffset; // enables native indexing |
2873 | } |
2874 | return ut; |
2875 | } |
2876 | |