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1 | /////////////////////////////////////////////////////////////////////////////// | |
2 | // Name: wx/buffer.h | |
3 | // Purpose: auto buffer classes: buffers which automatically free memory | |
4 | // Author: Vadim Zeitlin | |
5 | // Modified by: | |
6 | // Created: 12.04.99 | |
7 | // RCS-ID: $Id$ | |
8 | // Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr> | |
9 | // Licence: wxWindows licence | |
10 | /////////////////////////////////////////////////////////////////////////////// | |
11 | ||
12 | #ifndef _WX_BUFFER_H | |
13 | #define _WX_BUFFER_H | |
14 | ||
15 | #include "wx/chartype.h" | |
16 | #include "wx/wxcrtbase.h" | |
17 | ||
18 | #ifndef __WXPALMOS5__ | |
19 | #include <stdlib.h> // malloc() and free() | |
20 | #endif // ! __WXPALMOS5__ | |
21 | ||
22 | class WXDLLIMPEXP_FWD_BASE wxCStrData; | |
23 | ||
24 | // ---------------------------------------------------------------------------- | |
25 | // Special classes for (wide) character strings: they use malloc/free instead | |
26 | // of new/delete | |
27 | // ---------------------------------------------------------------------------- | |
28 | ||
29 | // helpers used by wxCharTypeBuffer | |
30 | namespace wxPrivate | |
31 | { | |
32 | ||
33 | struct UntypedBufferData | |
34 | { | |
35 | enum Kind | |
36 | { | |
37 | Owned, | |
38 | NonOwned | |
39 | }; | |
40 | ||
41 | UntypedBufferData(void *str, size_t len, Kind kind = Owned) | |
42 | : m_str(str), m_length(len), m_ref(1), m_owned(kind == Owned) {} | |
43 | ||
44 | ~UntypedBufferData() | |
45 | { | |
46 | if ( m_owned ) | |
47 | free(m_str); | |
48 | } | |
49 | ||
50 | void *m_str; | |
51 | size_t m_length; | |
52 | ||
53 | // "short" to have sizeof(Data)=12 on 32bit archs | |
54 | unsigned short m_ref; | |
55 | ||
56 | bool m_owned; | |
57 | }; | |
58 | ||
59 | // NB: this is defined in string.cpp and not the (non-existent) buffer.cpp | |
60 | WXDLLIMPEXP_BASE UntypedBufferData * GetUntypedNullData(); | |
61 | ||
62 | } // namespace wxPrivate | |
63 | ||
64 | ||
65 | // Reference-counted character buffer for storing string data. The buffer | |
66 | // is only valid for as long as the "parent" object that provided the data | |
67 | // is valid; see wxCharTypeBuffer<T> for persistent variant. | |
68 | template <typename T> | |
69 | class wxScopedCharTypeBuffer | |
70 | { | |
71 | public: | |
72 | typedef T CharType; | |
73 | ||
74 | wxScopedCharTypeBuffer() | |
75 | { | |
76 | m_data = GetNullData(); | |
77 | } | |
78 | ||
79 | // Creates "non-owned" buffer, i.e. 'str' is not owned by the buffer | |
80 | // and doesn't get freed by dtor. Used e.g. to point to wxString's internal | |
81 | // storage. | |
82 | static | |
83 | const wxScopedCharTypeBuffer CreateNonOwned(const CharType *str, | |
84 | size_t len = wxNO_LEN) | |
85 | { | |
86 | if ( len == wxNO_LEN ) | |
87 | len = wxStrlen(str); | |
88 | ||
89 | wxScopedCharTypeBuffer buf; | |
90 | if ( str ) | |
91 | buf.m_data = new Data(const_cast<CharType*>(str), len, Data::NonOwned); | |
92 | return buf; | |
93 | } | |
94 | ||
95 | // Creates "owned" buffer, i.e. takes over ownership of 'str' and frees it | |
96 | // in dtor (if ref.count reaches 0). | |
97 | static | |
98 | const wxScopedCharTypeBuffer CreateOwned(CharType *str, | |
99 | size_t len = wxNO_LEN ) | |
100 | { | |
101 | if ( len == wxNO_LEN ) | |
102 | len = wxStrlen(str); | |
103 | ||
104 | wxScopedCharTypeBuffer buf; | |
105 | if ( str ) | |
106 | buf.m_data = new Data(str, len); | |
107 | return buf; | |
108 | } | |
109 | ||
110 | wxScopedCharTypeBuffer(const wxScopedCharTypeBuffer& src) | |
111 | { | |
112 | m_data = src.m_data; | |
113 | IncRef(); | |
114 | } | |
115 | ||
116 | wxScopedCharTypeBuffer& operator=(const wxScopedCharTypeBuffer& src) | |
117 | { | |
118 | if ( &src == this ) | |
119 | return *this; | |
120 | ||
121 | DecRef(); | |
122 | m_data = src.m_data; | |
123 | IncRef(); | |
124 | ||
125 | return *this; | |
126 | } | |
127 | ||
128 | ~wxScopedCharTypeBuffer() | |
129 | { | |
130 | DecRef(); | |
131 | } | |
132 | ||
133 | // NB: this method is only const for backward compatibility. It used to | |
134 | // be needed for auto_ptr-like semantics of the copy ctor, but now | |
135 | // that ref-counting is used, it's not really needed. | |
136 | CharType *release() const | |
137 | { | |
138 | if ( m_data == GetNullData() ) | |
139 | return NULL; | |
140 | ||
141 | wxASSERT_MSG( m_data->m_owned, wxT("can't release non-owned buffer") ); | |
142 | wxASSERT_MSG( m_data->m_ref == 1, wxT("can't release shared buffer") ); | |
143 | ||
144 | CharType * const p = m_data->Get(); | |
145 | ||
146 | wxScopedCharTypeBuffer *self = const_cast<wxScopedCharTypeBuffer*>(this); | |
147 | self->m_data->Set(NULL, 0); | |
148 | self->DecRef(); | |
149 | ||
150 | return p; | |
151 | } | |
152 | ||
153 | void reset() | |
154 | { | |
155 | DecRef(); | |
156 | } | |
157 | ||
158 | CharType *data() { return m_data->Get(); } | |
159 | const CharType *data() const { return m_data->Get(); } | |
160 | operator const CharType *() const { return data(); } | |
161 | CharType operator[](size_t n) const { return data()[n]; } | |
162 | ||
163 | size_t length() const { return m_data->m_length; } | |
164 | ||
165 | protected: | |
166 | // reference-counted data | |
167 | struct Data : public wxPrivate::UntypedBufferData | |
168 | { | |
169 | Data(CharType *str, size_t len, Kind kind = Owned) | |
170 | : wxPrivate::UntypedBufferData(str, len, kind) | |
171 | { | |
172 | } | |
173 | ||
174 | CharType *Get() const { return static_cast<CharType *>(m_str); } | |
175 | void Set(CharType *str, size_t len) | |
176 | { | |
177 | m_str = str; | |
178 | m_length = len; | |
179 | } | |
180 | }; | |
181 | ||
182 | // placeholder for NULL string, to simplify this code | |
183 | static Data *GetNullData() | |
184 | { | |
185 | return static_cast<Data *>(wxPrivate::GetUntypedNullData()); | |
186 | } | |
187 | ||
188 | void IncRef() | |
189 | { | |
190 | if ( m_data == GetNullData() ) // exception, not ref-counted | |
191 | return; | |
192 | m_data->m_ref++; | |
193 | } | |
194 | ||
195 | void DecRef() | |
196 | { | |
197 | if ( m_data == GetNullData() ) // exception, not ref-counted | |
198 | return; | |
199 | if ( --m_data->m_ref == 0 ) | |
200 | delete m_data; | |
201 | m_data = GetNullData(); | |
202 | } | |
203 | ||
204 | // sets this object to a be copy of 'other'; if 'src' is non-owned, | |
205 | // a deep copy is made and 'this' will contain new instance of the data | |
206 | void MakeOwnedCopyOf(const wxScopedCharTypeBuffer& src) | |
207 | { | |
208 | this->DecRef(); | |
209 | ||
210 | if ( src.m_data == this->GetNullData() ) | |
211 | { | |
212 | this->m_data = this->GetNullData(); | |
213 | } | |
214 | else if ( src.m_data->m_owned ) | |
215 | { | |
216 | this->m_data = src.m_data; | |
217 | this->IncRef(); | |
218 | } | |
219 | else | |
220 | { | |
221 | // if the scoped buffer had non-owned data, we have to make | |
222 | // a copy here, because src.m_data->m_str is valid only for as long | |
223 | // as 'src' exists | |
224 | this->m_data = new Data | |
225 | ( | |
226 | StrCopy(src.data(), src.length()), | |
227 | src.length() | |
228 | ); | |
229 | } | |
230 | } | |
231 | ||
232 | static CharType *StrCopy(const CharType *src, size_t len) | |
233 | { | |
234 | CharType *dst = (CharType*)malloc(sizeof(CharType) * (len + 1)); | |
235 | memcpy(dst, src, sizeof(CharType) * (len + 1)); | |
236 | return dst; | |
237 | } | |
238 | ||
239 | protected: | |
240 | Data *m_data; | |
241 | }; | |
242 | ||
243 | typedef wxScopedCharTypeBuffer<char> wxScopedCharBuffer; | |
244 | typedef wxScopedCharTypeBuffer<wchar_t> wxScopedWCharBuffer; | |
245 | ||
246 | ||
247 | // this buffer class always stores data in "owned" (persistent) manner | |
248 | template <typename T> | |
249 | class wxCharTypeBuffer : public wxScopedCharTypeBuffer<T> | |
250 | { | |
251 | protected: | |
252 | typedef typename wxScopedCharTypeBuffer<T>::Data Data; | |
253 | ||
254 | public: | |
255 | typedef T CharType; | |
256 | ||
257 | wxCharTypeBuffer(const CharType *str = NULL, size_t len = wxNO_LEN) | |
258 | { | |
259 | if ( str ) | |
260 | { | |
261 | if ( len == wxNO_LEN ) | |
262 | len = wxStrlen(str); | |
263 | this->m_data = new Data(StrCopy(str, len), len); | |
264 | } | |
265 | else | |
266 | { | |
267 | this->m_data = this->GetNullData(); | |
268 | } | |
269 | } | |
270 | ||
271 | wxCharTypeBuffer(size_t len) | |
272 | { | |
273 | this->m_data = | |
274 | new Data((CharType *)malloc((len + 1)*sizeof(CharType)), len); | |
275 | this->m_data->Get()[len] = (CharType)0; | |
276 | } | |
277 | ||
278 | wxCharTypeBuffer(const wxCharTypeBuffer& src) | |
279 | : wxScopedCharTypeBuffer<T>(src) {} | |
280 | ||
281 | wxCharTypeBuffer& operator=(const CharType *str) | |
282 | { | |
283 | this->DecRef(); | |
284 | ||
285 | if ( str ) | |
286 | this->m_data = new Data(wxStrdup(str), wxStrlen(str)); | |
287 | return *this; | |
288 | } | |
289 | ||
290 | wxCharTypeBuffer& operator=(const wxCharTypeBuffer& src) | |
291 | { | |
292 | wxScopedCharTypeBuffer<T>::operator=(src); | |
293 | return *this; | |
294 | } | |
295 | ||
296 | wxCharTypeBuffer(const wxScopedCharTypeBuffer<T>& src) | |
297 | { | |
298 | MakeOwnedCopyOf(src); | |
299 | } | |
300 | ||
301 | wxCharTypeBuffer& operator=(const wxScopedCharTypeBuffer<T>& src) | |
302 | { | |
303 | MakeOwnedCopyOf(src); | |
304 | return *this; | |
305 | } | |
306 | ||
307 | bool extend(size_t len) | |
308 | { | |
309 | wxASSERT_MSG( this->m_data->m_owned, "cannot extend non-owned buffer" ); | |
310 | wxASSERT_MSG( this->m_data->m_ref == 1, "can't extend shared buffer" ); | |
311 | ||
312 | CharType *str = | |
313 | (CharType *)realloc(this->data(), (len + 1) * sizeof(CharType)); | |
314 | if ( !str ) | |
315 | return false; | |
316 | ||
317 | if ( this->m_data == this->GetNullData() ) | |
318 | { | |
319 | this->m_data = new Data(str, len); | |
320 | } | |
321 | else | |
322 | { | |
323 | this->m_data->Set(str, len); | |
324 | this->m_data->m_owned = true; | |
325 | } | |
326 | ||
327 | return true; | |
328 | } | |
329 | ||
330 | void shrink(size_t len) | |
331 | { | |
332 | wxASSERT_MSG( this->m_data->m_owned, "cannot shrink non-owned buffer" ); | |
333 | wxASSERT_MSG( this->m_data->m_ref == 1, "can't shrink shared buffer" ); | |
334 | ||
335 | wxASSERT( len <= this->length() ); | |
336 | ||
337 | this->m_data->m_length = len; | |
338 | this->data()[len] = 0; | |
339 | } | |
340 | }; | |
341 | ||
342 | WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxScopedCharTypeBuffer<char> ) | |
343 | WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxCharTypeBuffer<char> ) | |
344 | ||
345 | class wxCharBuffer : public wxCharTypeBuffer<char> | |
346 | { | |
347 | public: | |
348 | typedef wxCharTypeBuffer<char> wxCharTypeBufferBase; | |
349 | typedef wxScopedCharTypeBuffer<char> wxScopedCharTypeBufferBase; | |
350 | ||
351 | wxCharBuffer(const wxCharTypeBufferBase& buf) | |
352 | : wxCharTypeBufferBase(buf) {} | |
353 | wxCharBuffer(const wxScopedCharTypeBufferBase& buf) | |
354 | : wxCharTypeBufferBase(buf) {} | |
355 | ||
356 | wxCharBuffer(const CharType *str = NULL) : wxCharTypeBufferBase(str) {} | |
357 | wxCharBuffer(size_t len) : wxCharTypeBufferBase(len) {} | |
358 | ||
359 | wxCharBuffer(const wxCStrData& cstr); | |
360 | }; | |
361 | ||
362 | WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxScopedCharTypeBuffer<wchar_t> ) | |
363 | WXDLLIMPEXP_TEMPLATE_INSTANCE_BASE( wxCharTypeBuffer<wchar_t> ) | |
364 | ||
365 | class wxWCharBuffer : public wxCharTypeBuffer<wchar_t> | |
366 | { | |
367 | public: | |
368 | typedef wxCharTypeBuffer<wchar_t> wxCharTypeBufferBase; | |
369 | typedef wxScopedCharTypeBuffer<wchar_t> wxScopedCharTypeBufferBase; | |
370 | ||
371 | wxWCharBuffer(const wxCharTypeBufferBase& buf) | |
372 | : wxCharTypeBufferBase(buf) {} | |
373 | wxWCharBuffer(const wxScopedCharTypeBufferBase& buf) | |
374 | : wxCharTypeBufferBase(buf) {} | |
375 | ||
376 | wxWCharBuffer(const CharType *str = NULL) : wxCharTypeBufferBase(str) {} | |
377 | wxWCharBuffer(size_t len) : wxCharTypeBufferBase(len) {} | |
378 | ||
379 | wxWCharBuffer(const wxCStrData& cstr); | |
380 | }; | |
381 | ||
382 | // wxCharTypeBuffer<T> implicitly convertible to T* | |
383 | template <typename T> | |
384 | class wxWritableCharTypeBuffer : public wxCharTypeBuffer<T> | |
385 | { | |
386 | public: | |
387 | typedef typename wxScopedCharTypeBuffer<T>::CharType CharType; | |
388 | ||
389 | wxWritableCharTypeBuffer(const wxScopedCharTypeBuffer<T>& src) | |
390 | : wxCharTypeBuffer<T>(src) {} | |
391 | // FIXME-UTF8: this won't be needed after converting mb_str()/wc_str() to | |
392 | // always return a buffer | |
393 | // + we should derive this class from wxScopedCharTypeBuffer | |
394 | // then | |
395 | wxWritableCharTypeBuffer(const CharType *str = NULL) | |
396 | : wxCharTypeBuffer<T>(str) {} | |
397 | ||
398 | operator CharType*() { return this->data(); } | |
399 | }; | |
400 | ||
401 | typedef wxWritableCharTypeBuffer<char> wxWritableCharBuffer; | |
402 | typedef wxWritableCharTypeBuffer<wchar_t> wxWritableWCharBuffer; | |
403 | ||
404 | ||
405 | #if wxUSE_UNICODE | |
406 | #define wxWxCharBuffer wxWCharBuffer | |
407 | ||
408 | #define wxMB2WXbuf wxWCharBuffer | |
409 | #define wxWX2MBbuf wxCharBuffer | |
410 | #if wxUSE_UNICODE_WCHAR | |
411 | #define wxWC2WXbuf wxChar* | |
412 | #define wxWX2WCbuf wxChar* | |
413 | #elif wxUSE_UNICODE_UTF8 | |
414 | #define wxWC2WXbuf wxWCharBuffer | |
415 | #define wxWX2WCbuf wxWCharBuffer | |
416 | #endif | |
417 | #else // ANSI | |
418 | #define wxWxCharBuffer wxCharBuffer | |
419 | ||
420 | #define wxMB2WXbuf wxChar* | |
421 | #define wxWX2MBbuf wxChar* | |
422 | #define wxWC2WXbuf wxCharBuffer | |
423 | #define wxWX2WCbuf wxWCharBuffer | |
424 | #endif // Unicode/ANSI | |
425 | ||
426 | // ---------------------------------------------------------------------------- | |
427 | // A class for holding growable data buffers (not necessarily strings) | |
428 | // ---------------------------------------------------------------------------- | |
429 | ||
430 | // This class manages the actual data buffer pointer and is ref-counted. | |
431 | class wxMemoryBufferData | |
432 | { | |
433 | public: | |
434 | // the initial size and also the size added by ResizeIfNeeded() | |
435 | enum { DefBufSize = 1024 }; | |
436 | ||
437 | friend class wxMemoryBuffer; | |
438 | ||
439 | // everyting is private as it can only be used by wxMemoryBuffer | |
440 | private: | |
441 | wxMemoryBufferData(size_t size = wxMemoryBufferData::DefBufSize) | |
442 | : m_data(size ? malloc(size) : NULL), m_size(size), m_len(0), m_ref(0) | |
443 | { | |
444 | } | |
445 | ~wxMemoryBufferData() { free(m_data); } | |
446 | ||
447 | ||
448 | void ResizeIfNeeded(size_t newSize) | |
449 | { | |
450 | if (newSize > m_size) | |
451 | { | |
452 | void *dataOld = m_data; | |
453 | m_data = realloc(m_data, newSize + wxMemoryBufferData::DefBufSize); | |
454 | if ( !m_data ) | |
455 | { | |
456 | free(dataOld); | |
457 | } | |
458 | ||
459 | m_size = newSize + wxMemoryBufferData::DefBufSize; | |
460 | } | |
461 | } | |
462 | ||
463 | void IncRef() { m_ref += 1; } | |
464 | void DecRef() | |
465 | { | |
466 | m_ref -= 1; | |
467 | if (m_ref == 0) // are there no more references? | |
468 | delete this; | |
469 | } | |
470 | ||
471 | void *release() | |
472 | { | |
473 | if ( m_data == NULL ) | |
474 | return NULL; | |
475 | ||
476 | wxASSERT_MSG( m_ref == 1, "can't release shared buffer" ); | |
477 | ||
478 | void *p = m_data; | |
479 | m_data = NULL; | |
480 | m_len = | |
481 | m_size = 0; | |
482 | ||
483 | return p; | |
484 | } | |
485 | ||
486 | ||
487 | // the buffer containing the data | |
488 | void *m_data; | |
489 | ||
490 | // the size of the buffer | |
491 | size_t m_size; | |
492 | ||
493 | // the amount of data currently in the buffer | |
494 | size_t m_len; | |
495 | ||
496 | // the reference count | |
497 | size_t m_ref; | |
498 | ||
499 | wxDECLARE_NO_COPY_CLASS(wxMemoryBufferData); | |
500 | }; | |
501 | ||
502 | ||
503 | class wxMemoryBuffer | |
504 | { | |
505 | public: | |
506 | // ctor and dtor | |
507 | wxMemoryBuffer(size_t size = wxMemoryBufferData::DefBufSize) | |
508 | { | |
509 | m_bufdata = new wxMemoryBufferData(size); | |
510 | m_bufdata->IncRef(); | |
511 | } | |
512 | ||
513 | ~wxMemoryBuffer() { m_bufdata->DecRef(); } | |
514 | ||
515 | ||
516 | // copy and assignment | |
517 | wxMemoryBuffer(const wxMemoryBuffer& src) | |
518 | : m_bufdata(src.m_bufdata) | |
519 | { | |
520 | m_bufdata->IncRef(); | |
521 | } | |
522 | ||
523 | wxMemoryBuffer& operator=(const wxMemoryBuffer& src) | |
524 | { | |
525 | if (&src != this) | |
526 | { | |
527 | m_bufdata->DecRef(); | |
528 | m_bufdata = src.m_bufdata; | |
529 | m_bufdata->IncRef(); | |
530 | } | |
531 | return *this; | |
532 | } | |
533 | ||
534 | ||
535 | // Accessors | |
536 | void *GetData() const { return m_bufdata->m_data; } | |
537 | size_t GetBufSize() const { return m_bufdata->m_size; } | |
538 | size_t GetDataLen() const { return m_bufdata->m_len; } | |
539 | ||
540 | void SetBufSize(size_t size) { m_bufdata->ResizeIfNeeded(size); } | |
541 | void SetDataLen(size_t len) | |
542 | { | |
543 | wxASSERT(len <= m_bufdata->m_size); | |
544 | m_bufdata->m_len = len; | |
545 | } | |
546 | ||
547 | // Ensure the buffer is big enough and return a pointer to it | |
548 | void *GetWriteBuf(size_t sizeNeeded) | |
549 | { | |
550 | m_bufdata->ResizeIfNeeded(sizeNeeded); | |
551 | return m_bufdata->m_data; | |
552 | } | |
553 | ||
554 | // Update the length after the write | |
555 | void UngetWriteBuf(size_t sizeUsed) { SetDataLen(sizeUsed); } | |
556 | ||
557 | // Like the above, but appends to the buffer | |
558 | void *GetAppendBuf(size_t sizeNeeded) | |
559 | { | |
560 | m_bufdata->ResizeIfNeeded(m_bufdata->m_len + sizeNeeded); | |
561 | return (char*)m_bufdata->m_data + m_bufdata->m_len; | |
562 | } | |
563 | ||
564 | // Update the length after the append | |
565 | void UngetAppendBuf(size_t sizeUsed) | |
566 | { | |
567 | SetDataLen(m_bufdata->m_len + sizeUsed); | |
568 | } | |
569 | ||
570 | // Other ways to append to the buffer | |
571 | void AppendByte(char data) | |
572 | { | |
573 | wxCHECK_RET( m_bufdata->m_data, wxT("invalid wxMemoryBuffer") ); | |
574 | ||
575 | m_bufdata->ResizeIfNeeded(m_bufdata->m_len + 1); | |
576 | *(((char*)m_bufdata->m_data) + m_bufdata->m_len) = data; | |
577 | m_bufdata->m_len += 1; | |
578 | } | |
579 | ||
580 | void AppendData(const void *data, size_t len) | |
581 | { | |
582 | memcpy(GetAppendBuf(len), data, len); | |
583 | UngetAppendBuf(len); | |
584 | } | |
585 | ||
586 | operator const char *() const { return (const char*)GetData(); } | |
587 | ||
588 | // gives up ownership of data, returns the pointer; after this call, | |
589 | // data isn't freed by the buffer and its content is resent to empty | |
590 | void *release() | |
591 | { | |
592 | return m_bufdata->release(); | |
593 | } | |
594 | ||
595 | private: | |
596 | wxMemoryBufferData* m_bufdata; | |
597 | }; | |
598 | ||
599 | // ---------------------------------------------------------------------------- | |
600 | // template class for any kind of data | |
601 | // ---------------------------------------------------------------------------- | |
602 | ||
603 | // TODO | |
604 | ||
605 | #endif // _WX_BUFFER_H |