| 1 | ///////////////////////////////////////////////////////////////////////////// |
| 2 | // Name: src/common/stringimpl.cpp |
| 3 | // Purpose: wxString class |
| 4 | // Author: Vadim Zeitlin, Ryan Norton |
| 5 | // Modified by: |
| 6 | // Created: 29/01/98 |
| 7 | // RCS-ID: $Id$ |
| 8 | // Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr> |
| 9 | // (c) 2004 Ryan Norton <wxprojects@comcast.net> |
| 10 | // Licence: wxWindows licence |
| 11 | ///////////////////////////////////////////////////////////////////////////// |
| 12 | |
| 13 | /* |
| 14 | * About ref counting: |
| 15 | * 1) all empty strings use g_strEmpty, nRefs = -1 (set in Init()) |
| 16 | * 2) AllocBuffer() sets nRefs to 1, Lock() increments it by one |
| 17 | * 3) Unlock() decrements nRefs and frees memory if it goes to 0 |
| 18 | */ |
| 19 | |
| 20 | // =========================================================================== |
| 21 | // headers, declarations, constants |
| 22 | // =========================================================================== |
| 23 | |
| 24 | // For compilers that support precompilation, includes "wx.h". |
| 25 | #include "wx/wxprec.h" |
| 26 | |
| 27 | #ifdef __BORLANDC__ |
| 28 | #pragma hdrstop |
| 29 | #endif |
| 30 | |
| 31 | #ifndef WX_PRECOMP |
| 32 | #include "wx/stringimpl.h" |
| 33 | #include "wx/wxcrt.h" |
| 34 | #endif |
| 35 | |
| 36 | #include <ctype.h> |
| 37 | |
| 38 | #ifndef __WXWINCE__ |
| 39 | #include <errno.h> |
| 40 | #endif |
| 41 | |
| 42 | #include <string.h> |
| 43 | #include <stdlib.h> |
| 44 | |
| 45 | // allocating extra space for each string consumes more memory but speeds up |
| 46 | // the concatenation operations (nLen is the current string's length) |
| 47 | // NB: EXTRA_ALLOC must be >= 0! |
| 48 | #define EXTRA_ALLOC (19 - nLen % 16) |
| 49 | |
| 50 | |
| 51 | // string handling functions used by wxString: |
| 52 | #if wxUSE_UNICODE_UTF8 |
| 53 | #define wxStringMemcpy memcpy |
| 54 | #define wxStringMemcmp memcmp |
| 55 | #define wxStringMemchr memchr |
| 56 | #else |
| 57 | #define wxStringMemcpy wxTmemcpy |
| 58 | #define wxStringMemcmp wxTmemcmp |
| 59 | #define wxStringMemchr wxTmemchr |
| 60 | #endif |
| 61 | |
| 62 | |
| 63 | // --------------------------------------------------------------------------- |
| 64 | // static class variables definition |
| 65 | // --------------------------------------------------------------------------- |
| 66 | |
| 67 | #if !wxUSE_STL_BASED_WXSTRING |
| 68 | //According to STL _must_ be a -1 size_t |
| 69 | const size_t wxStringImpl::npos = (size_t) -1; |
| 70 | #endif |
| 71 | |
| 72 | // ---------------------------------------------------------------------------- |
| 73 | // static data |
| 74 | // ---------------------------------------------------------------------------- |
| 75 | |
| 76 | #if wxUSE_STL_BASED_WXSTRING |
| 77 | |
| 78 | // FIXME-UTF8: get rid of this, have only one wxEmptyString |
| 79 | #if wxUSE_UNICODE_UTF8 |
| 80 | extern const wxStringCharType WXDLLIMPEXP_BASE *wxEmptyStringImpl = ""; |
| 81 | #endif |
| 82 | extern const wxChar WXDLLIMPEXP_BASE *wxEmptyString = _T(""); |
| 83 | |
| 84 | #else |
| 85 | |
| 86 | // for an empty string, GetStringData() will return this address: this |
| 87 | // structure has the same layout as wxStringData and it's data() method will |
| 88 | // return the empty string (dummy pointer) |
| 89 | static const struct |
| 90 | { |
| 91 | wxStringData data; |
| 92 | wxStringCharType dummy; |
| 93 | } g_strEmpty = { {-1, 0, 0}, wxT('\0') }; |
| 94 | |
| 95 | // empty C style string: points to 'string data' byte of g_strEmpty |
| 96 | #if wxUSE_UNICODE_UTF8 |
| 97 | // FIXME-UTF8: get rid of this, have only one wxEmptyString |
| 98 | extern const wxStringCharType WXDLLIMPEXP_BASE *wxEmptyStringImpl = &g_strEmpty.dummy; |
| 99 | extern const wxChar WXDLLIMPEXP_BASE *wxEmptyString = _T(""); |
| 100 | #else |
| 101 | extern const wxStringCharType WXDLLIMPEXP_BASE *wxEmptyString = &g_strEmpty.dummy; |
| 102 | #endif |
| 103 | |
| 104 | #endif |
| 105 | |
| 106 | |
| 107 | #if !wxUSE_STL_BASED_WXSTRING |
| 108 | |
| 109 | // ---------------------------------------------------------------------------- |
| 110 | // private classes |
| 111 | // ---------------------------------------------------------------------------- |
| 112 | |
| 113 | // this small class is used to gather statistics for performance tuning |
| 114 | |
| 115 | // uncomment this to enable gathering of some statistics about wxString |
| 116 | // efficiency |
| 117 | //#define WXSTRING_STATISTICS |
| 118 | |
| 119 | #ifdef WXSTRING_STATISTICS |
| 120 | class Averager |
| 121 | { |
| 122 | public: |
| 123 | Averager(const wxStringCharType *sz) { m_sz = sz; m_nTotal = m_nCount = 0; } |
| 124 | ~Averager() |
| 125 | { |
| 126 | wxPrintf("wxString %s: total = %lu, average = %f\n", |
| 127 | m_sz, m_nTotal, ((float)m_nTotal)/m_nCount); |
| 128 | } |
| 129 | |
| 130 | void Add(size_t n) { m_nTotal += n; m_nCount++; } |
| 131 | |
| 132 | private: |
| 133 | unsigned long m_nCount, m_nTotal; |
| 134 | const wxStringCharType *m_sz; |
| 135 | } g_averageLength("allocation size"), |
| 136 | g_averageSummandLength("summand length"), |
| 137 | g_averageConcatHit("hit probability in concat"), |
| 138 | g_averageInitialLength("initial string length"); |
| 139 | |
| 140 | #define STATISTICS_ADD(av, val) g_average##av.Add(val) |
| 141 | #else |
| 142 | #define STATISTICS_ADD(av, val) |
| 143 | #endif // WXSTRING_STATISTICS |
| 144 | |
| 145 | // =========================================================================== |
| 146 | // wxStringData class deallocation |
| 147 | // =========================================================================== |
| 148 | |
| 149 | #if defined(__VISUALC__) && defined(_MT) && !defined(_DLL) |
| 150 | # pragma message (__FILE__ ": building with Multithreaded non DLL runtime has a performance impact on wxString!") |
| 151 | void wxStringData::Free() |
| 152 | { |
| 153 | free(this); |
| 154 | } |
| 155 | #endif |
| 156 | |
| 157 | // =========================================================================== |
| 158 | // wxStringImpl |
| 159 | // =========================================================================== |
| 160 | |
| 161 | // takes nLength elements of psz starting at nPos |
| 162 | void wxStringImpl::InitWith(const wxStringCharType *psz, |
| 163 | size_t nPos, size_t nLength) |
| 164 | { |
| 165 | Init(); |
| 166 | |
| 167 | // if the length is not given, assume the string to be NUL terminated |
| 168 | if ( nLength == npos ) { |
| 169 | wxASSERT_MSG( nPos <= wxStrlen(psz), _T("index out of bounds") ); |
| 170 | |
| 171 | nLength = wxStrlen(psz + nPos); |
| 172 | } |
| 173 | |
| 174 | STATISTICS_ADD(InitialLength, nLength); |
| 175 | |
| 176 | if ( nLength > 0 ) { |
| 177 | // trailing '\0' is written in AllocBuffer() |
| 178 | if ( !AllocBuffer(nLength) ) { |
| 179 | wxFAIL_MSG( _T("out of memory in wxStringImpl::InitWith") ); |
| 180 | return; |
| 181 | } |
| 182 | wxStringMemcpy(m_pchData, psz + nPos, nLength); |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | wxStringImpl::wxStringImpl(const_iterator first, const_iterator last) |
| 187 | { |
| 188 | if ( last >= first ) |
| 189 | { |
| 190 | InitWith(first.GetPtr(), 0, last - first); |
| 191 | } |
| 192 | else |
| 193 | { |
| 194 | wxFAIL_MSG( _T("first must be before last") ); |
| 195 | Init(); |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | wxStringImpl::wxStringImpl(size_type n, wxStringCharType ch) |
| 200 | { |
| 201 | Init(); |
| 202 | append(n, ch); |
| 203 | } |
| 204 | |
| 205 | // --------------------------------------------------------------------------- |
| 206 | // memory allocation |
| 207 | // --------------------------------------------------------------------------- |
| 208 | |
| 209 | // allocates memory needed to store a C string of length nLen |
| 210 | bool wxStringImpl::AllocBuffer(size_t nLen) |
| 211 | { |
| 212 | // allocating 0 sized buffer doesn't make sense, all empty strings should |
| 213 | // reuse g_strEmpty |
| 214 | wxASSERT( nLen > 0 ); |
| 215 | |
| 216 | // make sure that we don't overflow |
| 217 | wxCHECK( nLen < (INT_MAX / sizeof(wxStringCharType)) - |
| 218 | (sizeof(wxStringData) + EXTRA_ALLOC + 1), false ); |
| 219 | |
| 220 | STATISTICS_ADD(Length, nLen); |
| 221 | |
| 222 | // allocate memory: |
| 223 | // 1) one extra character for '\0' termination |
| 224 | // 2) sizeof(wxStringData) for housekeeping info |
| 225 | wxStringData* pData = (wxStringData*) |
| 226 | malloc(sizeof(wxStringData) + (nLen + EXTRA_ALLOC + 1)*sizeof(wxStringCharType)); |
| 227 | |
| 228 | if ( pData == NULL ) { |
| 229 | // allocation failures are handled by the caller |
| 230 | return false; |
| 231 | } |
| 232 | |
| 233 | pData->nRefs = 1; |
| 234 | pData->nDataLength = nLen; |
| 235 | pData->nAllocLength = nLen + EXTRA_ALLOC; |
| 236 | m_pchData = pData->data(); // data starts after wxStringData |
| 237 | m_pchData[nLen] = wxT('\0'); |
| 238 | return true; |
| 239 | } |
| 240 | |
| 241 | // must be called before changing this string |
| 242 | bool wxStringImpl::CopyBeforeWrite() |
| 243 | { |
| 244 | wxStringData* pData = GetStringData(); |
| 245 | |
| 246 | if ( pData->IsShared() ) { |
| 247 | pData->Unlock(); // memory not freed because shared |
| 248 | size_t nLen = pData->nDataLength; |
| 249 | if ( !AllocBuffer(nLen) ) { |
| 250 | // allocation failures are handled by the caller |
| 251 | return false; |
| 252 | } |
| 253 | wxStringMemcpy(m_pchData, pData->data(), nLen); |
| 254 | } |
| 255 | |
| 256 | wxASSERT( !GetStringData()->IsShared() ); // we must be the only owner |
| 257 | |
| 258 | return true; |
| 259 | } |
| 260 | |
| 261 | // must be called before replacing contents of this string |
| 262 | bool wxStringImpl::AllocBeforeWrite(size_t nLen) |
| 263 | { |
| 264 | wxASSERT( nLen != 0 ); // doesn't make any sense |
| 265 | |
| 266 | // must not share string and must have enough space |
| 267 | wxStringData* pData = GetStringData(); |
| 268 | if ( pData->IsShared() || pData->IsEmpty() ) { |
| 269 | // can't work with old buffer, get new one |
| 270 | pData->Unlock(); |
| 271 | if ( !AllocBuffer(nLen) ) { |
| 272 | // allocation failures are handled by the caller |
| 273 | return false; |
| 274 | } |
| 275 | } |
| 276 | else { |
| 277 | if ( nLen > pData->nAllocLength ) { |
| 278 | // realloc the buffer instead of calling malloc() again, this is more |
| 279 | // efficient |
| 280 | STATISTICS_ADD(Length, nLen); |
| 281 | |
| 282 | nLen += EXTRA_ALLOC; |
| 283 | |
| 284 | pData = (wxStringData*) |
| 285 | realloc(pData, |
| 286 | sizeof(wxStringData) + (nLen + 1)*sizeof(wxStringCharType)); |
| 287 | |
| 288 | if ( pData == NULL ) { |
| 289 | // allocation failures are handled by the caller |
| 290 | // keep previous data since reallocation failed |
| 291 | return false; |
| 292 | } |
| 293 | |
| 294 | pData->nAllocLength = nLen; |
| 295 | m_pchData = pData->data(); |
| 296 | } |
| 297 | } |
| 298 | |
| 299 | wxASSERT( !GetStringData()->IsShared() ); // we must be the only owner |
| 300 | |
| 301 | // it doesn't really matter what the string length is as it's going to be |
| 302 | // overwritten later but, for extra safety, set it to 0 for now as we may |
| 303 | // have some junk in m_pchData |
| 304 | GetStringData()->nDataLength = 0; |
| 305 | |
| 306 | return true; |
| 307 | } |
| 308 | |
| 309 | wxStringImpl& wxStringImpl::append(size_t n, wxStringCharType ch) |
| 310 | { |
| 311 | size_type len = length(); |
| 312 | |
| 313 | if ( !Alloc(len + n) || !CopyBeforeWrite() ) { |
| 314 | wxFAIL_MSG( _T("out of memory in wxStringImpl::append") ); |
| 315 | return *this; |
| 316 | } |
| 317 | GetStringData()->nDataLength = len + n; |
| 318 | m_pchData[len + n] = '\0'; |
| 319 | for ( size_t i = 0; i < n; ++i ) |
| 320 | m_pchData[len + i] = ch; |
| 321 | return *this; |
| 322 | } |
| 323 | |
| 324 | void wxStringImpl::resize(size_t nSize, wxStringCharType ch) |
| 325 | { |
| 326 | size_t len = length(); |
| 327 | |
| 328 | if ( nSize < len ) |
| 329 | { |
| 330 | erase(begin() + nSize, end()); |
| 331 | } |
| 332 | else if ( nSize > len ) |
| 333 | { |
| 334 | append(nSize - len, ch); |
| 335 | } |
| 336 | //else: we have exactly the specified length, nothing to do |
| 337 | } |
| 338 | |
| 339 | // allocate enough memory for nLen characters |
| 340 | bool wxStringImpl::Alloc(size_t nLen) |
| 341 | { |
| 342 | wxStringData *pData = GetStringData(); |
| 343 | if ( pData->nAllocLength <= nLen ) { |
| 344 | if ( pData->IsEmpty() ) { |
| 345 | STATISTICS_ADD(Length, nLen); |
| 346 | |
| 347 | nLen += EXTRA_ALLOC; |
| 348 | |
| 349 | pData = (wxStringData *) |
| 350 | malloc(sizeof(wxStringData) + (nLen + 1)*sizeof(wxStringCharType)); |
| 351 | |
| 352 | if ( pData == NULL ) { |
| 353 | // allocation failure handled by caller |
| 354 | return false; |
| 355 | } |
| 356 | |
| 357 | pData->nRefs = 1; |
| 358 | pData->nDataLength = 0; |
| 359 | pData->nAllocLength = nLen; |
| 360 | m_pchData = pData->data(); // data starts after wxStringData |
| 361 | m_pchData[0u] = wxT('\0'); |
| 362 | } |
| 363 | else if ( pData->IsShared() ) { |
| 364 | pData->Unlock(); // memory not freed because shared |
| 365 | size_t nOldLen = pData->nDataLength; |
| 366 | if ( !AllocBuffer(nLen) ) { |
| 367 | // allocation failure handled by caller |
| 368 | return false; |
| 369 | } |
| 370 | // +1 to copy the terminator, too |
| 371 | memcpy(m_pchData, pData->data(), (nOldLen+1)*sizeof(wxStringCharType)); |
| 372 | GetStringData()->nDataLength = nOldLen; |
| 373 | } |
| 374 | else { |
| 375 | nLen += EXTRA_ALLOC; |
| 376 | |
| 377 | pData = (wxStringData *) |
| 378 | realloc(pData, sizeof(wxStringData) + (nLen + 1)*sizeof(wxStringCharType)); |
| 379 | |
| 380 | if ( pData == NULL ) { |
| 381 | // allocation failure handled by caller |
| 382 | // keep previous data since reallocation failed |
| 383 | return false; |
| 384 | } |
| 385 | |
| 386 | // it's not important if the pointer changed or not (the check for this |
| 387 | // is not faster than assigning to m_pchData in all cases) |
| 388 | pData->nAllocLength = nLen; |
| 389 | m_pchData = pData->data(); |
| 390 | } |
| 391 | } |
| 392 | //else: we've already got enough |
| 393 | return true; |
| 394 | } |
| 395 | |
| 396 | wxStringImpl::iterator wxStringImpl::begin() |
| 397 | { |
| 398 | if (length() > 0) |
| 399 | CopyBeforeWrite(); |
| 400 | return m_pchData; |
| 401 | } |
| 402 | |
| 403 | wxStringImpl::iterator wxStringImpl::end() |
| 404 | { |
| 405 | if (length() > 0) |
| 406 | CopyBeforeWrite(); |
| 407 | return m_pchData + length(); |
| 408 | } |
| 409 | |
| 410 | wxStringImpl::iterator wxStringImpl::erase(iterator it) |
| 411 | { |
| 412 | size_type idx = it - begin(); |
| 413 | erase(idx, 1); |
| 414 | return begin() + idx; |
| 415 | } |
| 416 | |
| 417 | wxStringImpl& wxStringImpl::erase(size_t nStart, size_t nLen) |
| 418 | { |
| 419 | wxASSERT(nStart <= length()); |
| 420 | size_t strLen = length() - nStart; |
| 421 | // delete nLen or up to the end of the string characters |
| 422 | nLen = strLen < nLen ? strLen : nLen; |
| 423 | wxStringImpl strTmp(c_str(), nStart); |
| 424 | strTmp.append(c_str() + nStart + nLen, length() - nStart - nLen); |
| 425 | |
| 426 | swap(strTmp); |
| 427 | return *this; |
| 428 | } |
| 429 | |
| 430 | wxStringImpl& wxStringImpl::insert(size_t nPos, |
| 431 | const wxStringCharType *sz, size_t n) |
| 432 | { |
| 433 | wxASSERT( nPos <= length() ); |
| 434 | |
| 435 | if ( n == npos ) n = wxStrlen(sz); |
| 436 | if ( n == 0 ) return *this; |
| 437 | |
| 438 | if ( !Alloc(length() + n) || !CopyBeforeWrite() ) { |
| 439 | wxFAIL_MSG( _T("out of memory in wxStringImpl::insert") ); |
| 440 | return *this; |
| 441 | } |
| 442 | |
| 443 | memmove(m_pchData + nPos + n, m_pchData + nPos, |
| 444 | (length() - nPos) * sizeof(wxStringCharType)); |
| 445 | memcpy(m_pchData + nPos, sz, n * sizeof(wxStringCharType)); |
| 446 | GetStringData()->nDataLength = length() + n; |
| 447 | m_pchData[length()] = '\0'; |
| 448 | |
| 449 | return *this; |
| 450 | } |
| 451 | |
| 452 | void wxStringImpl::swap(wxStringImpl& str) |
| 453 | { |
| 454 | wxStringCharType* tmp = str.m_pchData; |
| 455 | str.m_pchData = m_pchData; |
| 456 | m_pchData = tmp; |
| 457 | } |
| 458 | |
| 459 | size_t wxStringImpl::find(const wxStringImpl& str, size_t nStart) const |
| 460 | { |
| 461 | // deal with the special case of empty string first |
| 462 | const size_t nLen = length(); |
| 463 | const size_t nLenOther = str.length(); |
| 464 | |
| 465 | if ( !nLenOther ) |
| 466 | { |
| 467 | // empty string is a substring of anything |
| 468 | return 0; |
| 469 | } |
| 470 | |
| 471 | if ( !nLen ) |
| 472 | { |
| 473 | // the other string is non empty so can't be our substring |
| 474 | return npos; |
| 475 | } |
| 476 | |
| 477 | wxASSERT( str.GetStringData()->IsValid() ); |
| 478 | wxASSERT( nStart <= nLen ); |
| 479 | |
| 480 | const wxStringCharType * const other = str.c_str(); |
| 481 | |
| 482 | // anchor |
| 483 | const wxStringCharType* p = |
| 484 | (const wxStringCharType*)wxStringMemchr(c_str() + nStart, |
| 485 | *other, |
| 486 | nLen - nStart); |
| 487 | |
| 488 | if ( !p ) |
| 489 | return npos; |
| 490 | |
| 491 | while ( p - c_str() + nLenOther <= nLen && |
| 492 | wxStringMemcmp(p, other, nLenOther) ) |
| 493 | { |
| 494 | p++; |
| 495 | |
| 496 | // anchor again |
| 497 | p = (const wxStringCharType*) |
| 498 | wxStringMemchr(p, *other, nLen - (p - c_str())); |
| 499 | |
| 500 | if ( !p ) |
| 501 | return npos; |
| 502 | } |
| 503 | |
| 504 | return p - c_str() + nLenOther <= nLen ? p - c_str() : npos; |
| 505 | } |
| 506 | |
| 507 | size_t wxStringImpl::find(const wxStringCharType* sz, |
| 508 | size_t nStart, size_t n) const |
| 509 | { |
| 510 | return find(wxStringImpl(sz, n), nStart); |
| 511 | } |
| 512 | |
| 513 | size_t wxStringImpl::find(wxStringCharType ch, size_t nStart) const |
| 514 | { |
| 515 | wxASSERT( nStart <= length() ); |
| 516 | |
| 517 | const wxStringCharType *p = (const wxStringCharType*) |
| 518 | wxStringMemchr(c_str() + nStart, ch, length() - nStart); |
| 519 | |
| 520 | return p == NULL ? npos : p - c_str(); |
| 521 | } |
| 522 | |
| 523 | size_t wxStringImpl::rfind(const wxStringImpl& str, size_t nStart) const |
| 524 | { |
| 525 | wxASSERT( str.GetStringData()->IsValid() ); |
| 526 | wxASSERT( nStart == npos || nStart <= length() ); |
| 527 | |
| 528 | if ( length() >= str.length() ) |
| 529 | { |
| 530 | // avoids a corner case later |
| 531 | if ( length() == 0 && str.length() == 0 ) |
| 532 | return 0; |
| 533 | |
| 534 | // "top" is the point where search starts from |
| 535 | size_t top = length() - str.length(); |
| 536 | |
| 537 | if ( nStart == npos ) |
| 538 | nStart = length() - 1; |
| 539 | if ( nStart < top ) |
| 540 | top = nStart; |
| 541 | |
| 542 | const wxStringCharType *cursor = c_str() + top; |
| 543 | do |
| 544 | { |
| 545 | if ( wxStringMemcmp(cursor, str.c_str(), str.length()) == 0 ) |
| 546 | { |
| 547 | return cursor - c_str(); |
| 548 | } |
| 549 | } while ( cursor-- > c_str() ); |
| 550 | } |
| 551 | |
| 552 | return npos; |
| 553 | } |
| 554 | |
| 555 | size_t wxStringImpl::rfind(const wxStringCharType* sz, |
| 556 | size_t nStart, size_t n) const |
| 557 | { |
| 558 | return rfind(wxStringImpl(sz, n), nStart); |
| 559 | } |
| 560 | |
| 561 | size_t wxStringImpl::rfind(wxStringCharType ch, size_t nStart) const |
| 562 | { |
| 563 | if ( nStart == npos ) |
| 564 | { |
| 565 | nStart = length(); |
| 566 | } |
| 567 | else |
| 568 | { |
| 569 | wxASSERT( nStart <= length() ); |
| 570 | } |
| 571 | |
| 572 | const wxStringCharType *actual; |
| 573 | for ( actual = c_str() + ( nStart == npos ? length() : nStart + 1 ); |
| 574 | actual > c_str(); --actual ) |
| 575 | { |
| 576 | if ( *(actual - 1) == ch ) |
| 577 | return (actual - 1) - c_str(); |
| 578 | } |
| 579 | |
| 580 | return npos; |
| 581 | } |
| 582 | |
| 583 | wxStringImpl& wxStringImpl::replace(size_t nStart, size_t nLen, |
| 584 | const wxStringCharType *sz, size_t nCount) |
| 585 | { |
| 586 | // check and adjust parameters |
| 587 | const size_t lenOld = length(); |
| 588 | |
| 589 | wxASSERT_MSG( nStart <= lenOld, |
| 590 | _T("index out of bounds in wxStringImpl::replace") ); |
| 591 | size_t nEnd = nStart + nLen; |
| 592 | if ( nLen > lenOld - nStart ) |
| 593 | { |
| 594 | // nLen may be out of range, as it can be npos, just clump it down |
| 595 | nLen = lenOld - nStart; |
| 596 | nEnd = lenOld; |
| 597 | } |
| 598 | |
| 599 | if ( nCount == npos ) |
| 600 | nCount = wxStrlen(sz); |
| 601 | |
| 602 | // build the new string from 3 pieces: part of this string before nStart, |
| 603 | // the new substring and the part of this string after nStart+nLen |
| 604 | wxStringImpl tmp; |
| 605 | const size_t lenNew = lenOld + nCount - nLen; |
| 606 | if ( lenNew ) |
| 607 | { |
| 608 | tmp.AllocBuffer(lenOld + nCount - nLen); |
| 609 | |
| 610 | wxStringCharType *dst = tmp.m_pchData; |
| 611 | memcpy(dst, m_pchData, nStart*sizeof(wxStringCharType)); |
| 612 | dst += nStart; |
| 613 | |
| 614 | memcpy(dst, sz, nCount*sizeof(wxStringCharType)); |
| 615 | dst += nCount; |
| 616 | |
| 617 | memcpy(dst, m_pchData + nEnd, (lenOld - nEnd)*sizeof(wxStringCharType)); |
| 618 | } |
| 619 | |
| 620 | // and replace this string contents with the new one |
| 621 | swap(tmp); |
| 622 | return *this; |
| 623 | } |
| 624 | |
| 625 | wxStringImpl wxStringImpl::substr(size_t nStart, size_t nLen) const |
| 626 | { |
| 627 | if ( nLen == npos ) |
| 628 | nLen = length() - nStart; |
| 629 | return wxStringImpl(*this, nStart, nLen); |
| 630 | } |
| 631 | |
| 632 | // assigns one string to another |
| 633 | wxStringImpl& wxStringImpl::operator=(const wxStringImpl& stringSrc) |
| 634 | { |
| 635 | wxASSERT( stringSrc.GetStringData()->IsValid() ); |
| 636 | |
| 637 | // don't copy string over itself |
| 638 | if ( m_pchData != stringSrc.m_pchData ) { |
| 639 | if ( stringSrc.GetStringData()->IsEmpty() ) { |
| 640 | Reinit(); |
| 641 | } |
| 642 | else { |
| 643 | // adjust references |
| 644 | GetStringData()->Unlock(); |
| 645 | m_pchData = stringSrc.m_pchData; |
| 646 | GetStringData()->Lock(); |
| 647 | } |
| 648 | } |
| 649 | |
| 650 | return *this; |
| 651 | } |
| 652 | |
| 653 | // assigns a single character |
| 654 | wxStringImpl& wxStringImpl::operator=(wxStringCharType ch) |
| 655 | { |
| 656 | wxStringCharType c(ch); |
| 657 | if ( !AssignCopy(1, &c) ) { |
| 658 | wxFAIL_MSG( _T("out of memory in wxStringImpl::operator=(wxStringCharType)") ); |
| 659 | } |
| 660 | return *this; |
| 661 | } |
| 662 | |
| 663 | // assigns C string |
| 664 | wxStringImpl& wxStringImpl::operator=(const wxStringCharType *psz) |
| 665 | { |
| 666 | if ( !AssignCopy(wxStrlen(psz), psz) ) { |
| 667 | wxFAIL_MSG( _T("out of memory in wxStringImpl::operator=(const wxStringCharType *)") ); |
| 668 | } |
| 669 | return *this; |
| 670 | } |
| 671 | |
| 672 | // helper function: does real copy |
| 673 | bool wxStringImpl::AssignCopy(size_t nSrcLen, |
| 674 | const wxStringCharType *pszSrcData) |
| 675 | { |
| 676 | if ( nSrcLen == 0 ) { |
| 677 | Reinit(); |
| 678 | } |
| 679 | else { |
| 680 | if ( !AllocBeforeWrite(nSrcLen) ) { |
| 681 | // allocation failure handled by caller |
| 682 | return false; |
| 683 | } |
| 684 | memcpy(m_pchData, pszSrcData, nSrcLen*sizeof(wxStringCharType)); |
| 685 | GetStringData()->nDataLength = nSrcLen; |
| 686 | m_pchData[nSrcLen] = wxT('\0'); |
| 687 | } |
| 688 | return true; |
| 689 | } |
| 690 | |
| 691 | // --------------------------------------------------------------------------- |
| 692 | // string concatenation |
| 693 | // --------------------------------------------------------------------------- |
| 694 | |
| 695 | // add something to this string |
| 696 | bool wxStringImpl::ConcatSelf(size_t nSrcLen, |
| 697 | const wxStringCharType *pszSrcData, |
| 698 | size_t nMaxLen) |
| 699 | { |
| 700 | STATISTICS_ADD(SummandLength, nSrcLen); |
| 701 | |
| 702 | nSrcLen = nSrcLen < nMaxLen ? nSrcLen : nMaxLen; |
| 703 | |
| 704 | // concatenating an empty string is a NOP |
| 705 | if ( nSrcLen > 0 ) { |
| 706 | wxStringData *pData = GetStringData(); |
| 707 | size_t nLen = pData->nDataLength; |
| 708 | |
| 709 | // take special care when appending part of this string to itself: the code |
| 710 | // below reallocates our buffer and this invalidates pszSrcData pointer so |
| 711 | // we have to copy it in another temporary string in this case (but avoid |
| 712 | // doing this unnecessarily) |
| 713 | if ( pszSrcData >= m_pchData && pszSrcData < m_pchData + nLen ) |
| 714 | { |
| 715 | wxStringImpl tmp(pszSrcData, nSrcLen); |
| 716 | return ConcatSelf(nSrcLen, tmp.m_pchData, nSrcLen); |
| 717 | } |
| 718 | |
| 719 | size_t nNewLen = nLen + nSrcLen; |
| 720 | |
| 721 | // alloc new buffer if current is too small |
| 722 | if ( pData->IsShared() ) { |
| 723 | STATISTICS_ADD(ConcatHit, 0); |
| 724 | |
| 725 | // we have to allocate another buffer |
| 726 | wxStringData* pOldData = GetStringData(); |
| 727 | if ( !AllocBuffer(nNewLen) ) { |
| 728 | // allocation failure handled by caller |
| 729 | return false; |
| 730 | } |
| 731 | memcpy(m_pchData, pOldData->data(), nLen*sizeof(wxStringCharType)); |
| 732 | pOldData->Unlock(); |
| 733 | } |
| 734 | else if ( nNewLen > pData->nAllocLength ) { |
| 735 | STATISTICS_ADD(ConcatHit, 0); |
| 736 | |
| 737 | reserve(nNewLen); |
| 738 | // we have to grow the buffer |
| 739 | if ( capacity() < nNewLen ) { |
| 740 | // allocation failure handled by caller |
| 741 | return false; |
| 742 | } |
| 743 | } |
| 744 | else { |
| 745 | STATISTICS_ADD(ConcatHit, 1); |
| 746 | |
| 747 | // the buffer is already big enough |
| 748 | } |
| 749 | |
| 750 | // should be enough space |
| 751 | wxASSERT( nNewLen <= GetStringData()->nAllocLength ); |
| 752 | |
| 753 | // fast concatenation - all is done in our buffer |
| 754 | memcpy(m_pchData + nLen, pszSrcData, nSrcLen*sizeof(wxStringCharType)); |
| 755 | |
| 756 | m_pchData[nNewLen] = wxT('\0'); // put terminating '\0' |
| 757 | GetStringData()->nDataLength = nNewLen; // and fix the length |
| 758 | } |
| 759 | //else: the string to append was empty |
| 760 | return true; |
| 761 | } |
| 762 | |
| 763 | // get the pointer to writable buffer of (at least) nLen bytes |
| 764 | wxStringCharType *wxStringImpl::DoGetWriteBuf(size_t nLen) |
| 765 | { |
| 766 | if ( !AllocBeforeWrite(nLen) ) { |
| 767 | // allocation failure handled by caller |
| 768 | return NULL; |
| 769 | } |
| 770 | |
| 771 | wxASSERT( GetStringData()->nRefs == 1 ); |
| 772 | GetStringData()->Validate(false); |
| 773 | |
| 774 | return m_pchData; |
| 775 | } |
| 776 | |
| 777 | // put string back in a reasonable state after GetWriteBuf |
| 778 | void wxStringImpl::DoUngetWriteBuf() |
| 779 | { |
| 780 | DoUngetWriteBuf(wxStrlen(m_pchData)); |
| 781 | } |
| 782 | |
| 783 | void wxStringImpl::DoUngetWriteBuf(size_t nLen) |
| 784 | { |
| 785 | wxStringData * const pData = GetStringData(); |
| 786 | |
| 787 | wxASSERT_MSG( nLen < pData->nAllocLength, _T("buffer overrun") ); |
| 788 | |
| 789 | // the strings we store are always NUL-terminated |
| 790 | pData->data()[nLen] = _T('\0'); |
| 791 | pData->nDataLength = nLen; |
| 792 | pData->Validate(true); |
| 793 | } |
| 794 | |
| 795 | #endif // !wxUSE_STL_BASED_WXSTRING |