Bug fix in wxBufferedInputStream::SeekI
[wxWidgets.git] / src / common / stream.cpp
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: stream.cpp
3 // Purpose: wxStream base classes
4 // Author: Guilhem Lavaux
5 // Modified by:
6 // Created: 11/07/98
7 // RCS-ID: $Id$
8 // Copyright: (c) Guilhem Lavaux
9 // Licence: wxWindows license
10 /////////////////////////////////////////////////////////////////////////////
11
12 #ifdef __GNUG__
13 #pragma implementation "stream.h"
14 #endif
15
16 // For compilers that support precompilation, includes "wx.h".
17 #include "wx/wxprec.h"
18
19 #ifdef __BORLANDC__
20 #pragma hdrstop
21 #endif
22
23 #ifndef WX_PRECOMP
24 #include "wx/defs.h"
25 #endif
26
27 #if wxUSE_STREAMS
28
29 #include <ctype.h>
30 #include <wx/stream.h>
31 #include <wx/datstrm.h>
32 #include <wx/objstrm.h>
33
34 #define BUF_TEMP_SIZE 10000
35
36 // ----------------------------------------------------------------------------
37 // wxStreamBuffer
38 // ----------------------------------------------------------------------------
39
40 #define CHECK_ERROR(err) \
41 if (m_stream->m_lasterror == wxStream_NOERROR) \
42 m_stream->m_lasterror = err
43
44 wxStreamBuffer::wxStreamBuffer(wxStreamBase& stream, BufMode mode)
45 : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
46 m_buffer_size(0), m_fixed(TRUE), m_flushable(TRUE), m_stream(&stream),
47 m_mode(mode), m_destroybuf(FALSE), m_destroystream(FALSE)
48 {
49 }
50
51 wxStreamBuffer::wxStreamBuffer(BufMode mode)
52 : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
53 m_buffer_size(0), m_fixed(TRUE), m_flushable(FALSE), m_stream(NULL),
54 m_mode(mode), m_destroybuf(FALSE), m_destroystream(TRUE)
55 {
56 m_stream = new wxStreamBase();
57 }
58
59 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
60 {
61 m_buffer_start = buffer.m_buffer_start;
62 m_buffer_end = buffer.m_buffer_end;
63 m_buffer_pos = buffer.m_buffer_pos;
64 m_buffer_size = buffer.m_buffer_size;
65 m_fixed = buffer.m_fixed;
66 m_flushable = buffer.m_flushable;
67 m_stream = buffer.m_stream;
68 m_mode = buffer.m_mode;
69 m_destroybuf = FALSE;
70 m_destroystream = FALSE;
71 }
72
73 wxStreamBuffer::~wxStreamBuffer()
74 {
75 if (m_destroybuf)
76 wxDELETEA(m_buffer_start);
77 if (m_destroystream)
78 delete m_stream;
79 }
80
81 void wxStreamBuffer::SetBufferIO(char *buffer_start, char *buffer_end)
82 {
83 if (m_destroybuf)
84 wxDELETEA(m_buffer_start);
85 m_buffer_start = buffer_start;
86 m_buffer_end = buffer_end;
87
88 m_buffer_size = m_buffer_end-m_buffer_start;
89 m_destroybuf = FALSE;
90 ResetBuffer();
91 }
92
93 void wxStreamBuffer::SetBufferIO(size_t bufsize)
94 {
95 char *b_start;
96
97 if (m_destroybuf)
98 wxDELETEA(m_buffer_start);
99
100 if (!bufsize) {
101 m_buffer_start = NULL;
102 m_buffer_end = NULL;
103 m_buffer_pos = NULL;
104 m_buffer_size = 0;
105 return;
106 }
107
108 b_start = new char[bufsize];
109 SetBufferIO(b_start, b_start + bufsize);
110 m_destroybuf = TRUE;
111 }
112
113 void wxStreamBuffer::ResetBuffer()
114 {
115 m_stream->m_lasterror = wxStream_NOERROR;
116 m_stream->m_lastcount = 0;
117 if (m_mode == read)
118 m_buffer_pos = m_buffer_end;
119 else
120 m_buffer_pos = m_buffer_start;
121 }
122
123 bool wxStreamBuffer::FillBuffer()
124 {
125 size_t count;
126
127 count = m_stream->OnSysRead(m_buffer_start, m_buffer_size);
128 m_buffer_end = m_buffer_start+count;
129 m_buffer_pos = m_buffer_start;
130
131 if (count == 0)
132 return FALSE;
133 return TRUE;
134 }
135
136 bool wxStreamBuffer::FlushBuffer()
137 {
138 size_t count, current;
139
140 if (m_buffer_pos == m_buffer_start || !m_flushable)
141 return FALSE;
142
143 current = m_buffer_pos-m_buffer_start;
144 count = m_stream->OnSysWrite(m_buffer_start, current);
145 if (count != current)
146 return FALSE;
147 m_buffer_pos = m_buffer_start;
148
149 return TRUE;
150 }
151
152 void wxStreamBuffer::GetFromBuffer(void *buffer, size_t size)
153 {
154 size_t s_toget = m_buffer_end-m_buffer_pos;
155
156 if (size < s_toget)
157 s_toget = size;
158
159 memcpy(buffer, m_buffer_pos, s_toget);
160 m_buffer_pos += s_toget;
161 }
162
163 void wxStreamBuffer::PutToBuffer(const void *buffer, size_t size)
164 {
165 size_t s_toput = m_buffer_end-m_buffer_pos;
166
167 if (s_toput < size && !m_fixed) {
168 m_buffer_start = (char *)realloc(m_buffer_start, m_buffer_size+size);
169 // I round a bit
170 m_buffer_size += size;
171 m_buffer_end = m_buffer_start+m_buffer_size;
172 s_toput = size;
173 }
174 if (s_toput > size)
175 s_toput = size;
176 memcpy(m_buffer_pos, buffer, s_toput);
177 m_buffer_pos += s_toput;
178 }
179
180 void wxStreamBuffer::PutChar(char c)
181 {
182 wxASSERT(m_stream != NULL);
183
184 if (!m_buffer_size) {
185 m_stream->OnSysWrite(&c, 1);
186 return;
187 }
188
189 if (GetDataLeft() == 0 && !FlushBuffer()) {
190 CHECK_ERROR(wxStream_WRITE_ERR);
191 return;
192 }
193
194 PutToBuffer(&c, 1);
195 m_stream->m_lastcount = 1;
196 }
197
198 char wxStreamBuffer::GetChar()
199 {
200 char c;
201
202 wxASSERT(m_stream != NULL);
203
204 if (!m_buffer_size) {
205 m_stream->OnSysRead(&c, 1);
206 return c;
207 }
208
209 if (!GetDataLeft()) {
210 CHECK_ERROR(wxStream_READ_ERR);
211 return 0;
212 }
213
214 GetFromBuffer(&c, 1);
215
216 m_stream->m_lastcount = 1;
217 return c;
218 }
219
220 size_t wxStreamBuffer::Read(void *buffer, size_t size)
221 {
222 wxASSERT(m_stream != NULL);
223
224 if (m_mode == write)
225 return 0;
226
227 // ------------------
228 // Buffering disabled
229 // ------------------
230
231 m_stream->m_lasterror = wxStream_NOERROR;
232 if (!m_buffer_size)
233 return (m_stream->m_lastcount += m_stream->OnSysRead(buffer, size));
234
235 // -----------------
236 // Buffering enabled
237 // -----------------
238 size_t buf_left, orig_size = size;
239
240 while (size > 0) {
241 buf_left = GetDataLeft();
242
243 // First case: the requested buffer is larger than the stream buffer,
244 // we split it.
245 if (size > buf_left) {
246 GetFromBuffer(buffer, buf_left);
247 size -= buf_left;
248 buffer = (char *)buffer + buf_left; // ANSI C++ violation.
249
250 if (!FillBuffer()) {
251 CHECK_ERROR(wxStream_READ_ERR);
252 return (m_stream->m_lastcount = orig_size-size);
253 }
254 } else {
255
256 // Second case: we just copy from the stream buffer.
257 GetFromBuffer(buffer, size);
258 break;
259 }
260 }
261 return (m_stream->m_lastcount += orig_size);
262 }
263
264 size_t wxStreamBuffer::Read(wxStreamBuffer *s_buf)
265 {
266 char buf[BUF_TEMP_SIZE];
267 size_t s = 0, bytes_read = BUF_TEMP_SIZE;
268
269 if (m_mode == write)
270 return 0;
271
272 while (bytes_read != 0) {
273 bytes_read = Read(buf, bytes_read);
274 bytes_read = s_buf->Write(buf, bytes_read);
275 s += bytes_read;
276 }
277 return s;
278 }
279
280 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
281 {
282 wxASSERT(m_stream != NULL);
283
284 if (m_mode == read)
285 return 0;
286
287 // ------------------
288 // Buffering disabled
289 // ------------------
290
291 m_stream->m_lasterror = wxStream_NOERROR;
292 if (!m_buffer_size)
293 return (m_stream->m_lastcount = m_stream->OnSysWrite(buffer, size));
294
295 // ------------------
296 // Buffering enabled
297 // ------------------
298
299 size_t buf_left, orig_size = size;
300
301 while (size > 0) {
302 buf_left = m_buffer_end - m_buffer_pos;
303
304 // First case: the buffer to write is larger than the stream buffer,
305 // we split it
306 if (size > buf_left) {
307 PutToBuffer(buffer, buf_left);
308 size -= buf_left;
309 buffer = (char *)buffer + buf_left; // ANSI C++ violation.
310
311 if (!FlushBuffer()) {
312 CHECK_ERROR(wxStream_WRITE_ERR);
313 return (m_stream->m_lastcount = orig_size-size);
314 }
315
316 m_buffer_pos = m_buffer_start;
317
318 } else {
319
320 // Second case: just copy it in the stream buffer.
321 PutToBuffer(buffer, size);
322 break;
323 }
324 }
325 return (m_stream->m_lastcount = orig_size);
326 }
327
328 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
329 {
330 char buf[BUF_TEMP_SIZE];
331 size_t s = 0, bytes_count = BUF_TEMP_SIZE, b_count2;
332 wxInputStream *in_stream;
333
334 if (m_mode == read)
335 return 0;
336
337 in_stream = (wxInputStream *)sbuf->Stream();
338
339 while (bytes_count == BUF_TEMP_SIZE) {
340 b_count2 = sbuf->Read(buf, bytes_count);
341 bytes_count = Write(buf, b_count2);
342 if (b_count2 > bytes_count)
343 in_stream->Ungetch(buf+bytes_count, b_count2-bytes_count);
344 s += bytes_count;
345 }
346 return s;
347 }
348
349 off_t wxStreamBuffer::Seek(off_t pos, wxSeekMode mode)
350 {
351 off_t ret_off, diff, last_access;
352
353 last_access = GetLastAccess();
354
355 if (!m_flushable) {
356 diff = pos + GetIntPosition();
357 if (diff < 0 || diff > last_access)
358 return wxInvalidOffset;
359 SetIntPosition(diff);
360 return diff;
361 }
362
363 switch (mode) {
364 case wxFromStart: {
365 // We'll try to compute an internal position later ...
366 ret_off = m_stream->OnSysSeek(pos, wxFromStart);
367 ResetBuffer();
368 return ret_off;
369 }
370 case wxFromCurrent: {
371 diff = pos + GetIntPosition();
372
373 if ( (diff > last_access) || (diff < 0) ) {
374 // We must take into account the fact that we have read something
375 // previously.
376 if (diff < 0)
377 ret_off = m_stream->OnSysSeek(-(last_access-diff), wxFromCurrent);
378 // lastaccess + abs(diff) = lastaccess - diff here
379 else
380 ret_off = m_stream->OnSysSeek(diff-last_access, wxFromCurrent);
381 ResetBuffer();
382 return ret_off;
383 } else {
384 SetIntPosition(diff);
385 return pos;
386 }
387 }
388 case wxFromEnd:
389 // Hard to compute: always seek to the requested position.
390 ret_off = m_stream->OnSysSeek(pos, wxFromEnd);
391 ResetBuffer();
392 return ret_off;
393 }
394 return wxInvalidOffset;
395 }
396
397 off_t wxStreamBuffer::Tell() const
398 {
399 off_t pos;
400
401 if (m_flushable) {
402 pos = m_stream->OnSysTell();
403 if (pos == wxInvalidOffset)
404 return wxInvalidOffset;
405 return pos - GetLastAccess() + GetIntPosition();
406 } else
407 return GetIntPosition();
408 }
409
410 size_t wxStreamBuffer::GetDataLeft()
411 {
412 if (m_buffer_end == m_buffer_pos && m_flushable)
413 FillBuffer();
414 return m_buffer_end-m_buffer_pos;
415 }
416
417 // ----------------------------------------------------------------------------
418 // wxStreamBase
419 // ----------------------------------------------------------------------------
420
421 wxStreamBase::wxStreamBase()
422 {
423 m_lasterror = wxStream_NOERROR;
424 m_lastcount = 0;
425 }
426
427 wxStreamBase::~wxStreamBase()
428 {
429 }
430
431 size_t wxStreamBase::OnSysRead(void *WXUNUSED(buffer), size_t WXUNUSED(size))
432 {
433 return 0;
434 }
435
436 size_t wxStreamBase::OnSysWrite(const void *WXUNUSED(buffer), size_t WXUNUSED(bufsize))
437 {
438 return 0;
439 }
440
441 off_t wxStreamBase::OnSysSeek(off_t WXUNUSED(seek), wxSeekMode WXUNUSED(mode))
442 {
443 return wxInvalidOffset;
444 }
445
446 off_t wxStreamBase::OnSysTell() const
447 {
448 return wxInvalidOffset;
449 }
450
451 // ----------------------------------------------------------------------------
452 // wxInputStream
453 // ----------------------------------------------------------------------------
454
455 wxInputStream::wxInputStream()
456 : wxStreamBase(),
457 m_wback(NULL), m_wbacksize(0), m_wbackcur(0)
458 {
459 }
460
461 wxInputStream::~wxInputStream()
462 {
463 if (m_wback)
464 free(m_wback);
465 }
466
467 char *wxInputStream::AllocSpaceWBack(size_t needed_size)
468 {
469 char *temp_b;
470
471 m_wbacksize += needed_size;
472
473 if (!m_wback)
474 temp_b = (char *)malloc(m_wbacksize);
475 else
476 temp_b = (char *)realloc(m_wback, m_wbacksize);
477
478 if (!temp_b)
479 return NULL;
480 m_wback = temp_b;
481
482 return (char *)(m_wback+(m_wbacksize-needed_size));
483 }
484
485 size_t wxInputStream::GetWBack(char *buf, size_t bsize)
486 {
487 size_t s_toget = m_wbacksize-m_wbackcur;
488
489 if (!m_wback)
490 return 0;
491
492 if (bsize < s_toget)
493 s_toget = bsize;
494
495 memcpy(buf, (m_wback+m_wbackcur), s_toget);
496
497 m_wbackcur += s_toget;
498 if (m_wbackcur == m_wbacksize) {
499 free(m_wback);
500 m_wback = (char *)NULL;
501 m_wbacksize = 0;
502 m_wbackcur = 0;
503 }
504
505 return s_toget;
506 }
507
508 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
509 {
510 char *ptrback;
511
512 ptrback = AllocSpaceWBack(bufsize);
513 if (!ptrback)
514 return 0;
515
516 memcpy(ptrback, buf, bufsize);
517 return bufsize;
518 }
519
520 bool wxInputStream::Ungetch(char c)
521 {
522 char *ptrback;
523
524 ptrback = AllocSpaceWBack(1);
525 if (!ptrback)
526 return FALSE;
527
528 *ptrback = c;
529 return TRUE;
530 }
531
532 char wxInputStream::GetC()
533 {
534 char c;
535 Read(&c, 1);
536 return c;
537 }
538
539 wxInputStream& wxInputStream::Read(void *buffer, size_t size)
540 {
541 size_t retsize;
542 char *buf = (char *)buffer;
543
544 retsize = GetWBack(buf, size);
545 if (retsize == size) {
546 m_lastcount = size;
547 m_lasterror = wxStream_NOERROR;
548 return *this;
549 }
550 size -= retsize;
551 buf += retsize;
552
553 m_lastcount = OnSysRead(buf, size);
554 return *this;
555 }
556
557 char wxInputStream::Peek()
558 {
559 char c;
560
561 Read(&c, 1);
562 if (m_lasterror == wxStream_NOERROR) {
563 Ungetch(c);
564 return c;
565 }
566 return 0;
567 }
568
569 wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
570 {
571 char buf[BUF_TEMP_SIZE];
572 size_t bytes_read = BUF_TEMP_SIZE;
573
574 while (bytes_read == BUF_TEMP_SIZE) {
575 bytes_read = Read(buf, bytes_read).LastRead();
576 bytes_read = stream_out.Write(buf, bytes_read).LastWrite();
577 }
578 return *this;
579 }
580
581 off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
582 {
583 return OnSysSeek(pos, mode);
584 }
585
586 off_t wxInputStream::TellI() const
587 {
588 return OnSysTell();
589 }
590
591 // --------------------
592 // Overloaded operators
593 // --------------------
594
595 #if wxUSE_SERIAL
596 wxInputStream& wxInputStream::operator>>(wxObject *& obj)
597 {
598 wxObjectInputStream obj_s(*this);
599 obj = obj_s.LoadObject();
600 return *this;
601 }
602 #endif
603
604
605 // ----------------------------------------------------------------------------
606 // wxOutputStream
607 // ----------------------------------------------------------------------------
608 wxOutputStream::wxOutputStream()
609 : wxStreamBase()
610 {
611 }
612
613 wxOutputStream::~wxOutputStream()
614 {
615 }
616
617 wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)
618 {
619 m_lastcount = OnSysWrite(buffer, size);
620 return *this;
621 }
622
623 wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
624 {
625 stream_in.Read(*this);
626 return *this;
627 }
628
629 off_t wxOutputStream::TellO() const
630 {
631 return OnSysTell();
632 }
633
634 off_t wxOutputStream::SeekO(off_t pos, wxSeekMode mode)
635 {
636 return OnSysSeek(pos, mode);
637 }
638
639 void wxOutputStream::Sync()
640 {
641 }
642
643 #if wxUSE_SERIAL
644 wxOutputStream& wxOutputStream::operator<<(wxObject& obj)
645 {
646 wxObjectOutputStream obj_s(*this);
647 obj_s.SaveObject(obj);
648 return *this;
649 }
650 #endif
651
652 // ----------------------------------------------------------------------------
653 // wxFilterInputStream
654 // ----------------------------------------------------------------------------
655 wxFilterInputStream::wxFilterInputStream()
656 : wxInputStream()
657 {
658 }
659
660 wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
661 : wxInputStream()
662 {
663 m_parent_i_stream = &stream;
664 }
665
666 wxFilterInputStream::~wxFilterInputStream()
667 {
668 }
669
670 // ----------------------------------------------------------------------------
671 // wxFilterOutputStream
672 // ----------------------------------------------------------------------------
673 wxFilterOutputStream::wxFilterOutputStream()
674 : wxOutputStream()
675 {
676 }
677
678 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
679 : wxOutputStream()
680 {
681 m_parent_o_stream = &stream;
682 }
683
684 wxFilterOutputStream::~wxFilterOutputStream()
685 {
686 }
687
688 // ----------------------------------------------------------------------------
689 // wxBufferedInputStream
690 // ----------------------------------------------------------------------------
691 wxBufferedInputStream::wxBufferedInputStream(wxInputStream& s)
692 : wxFilterInputStream(s)
693 {
694 m_i_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::read);
695 m_i_streambuf->SetBufferIO(1024);
696 }
697
698 wxBufferedInputStream::~wxBufferedInputStream()
699 {
700 delete m_i_streambuf;
701 }
702
703 wxInputStream& wxBufferedInputStream::Read(void *buffer, size_t size)
704 {
705 size_t retsize;
706 char *buf = (char *)buffer;
707
708 retsize = GetWBack(buf, size);
709 m_lastcount = retsize;
710 if (retsize == size) {
711 m_lasterror = wxStream_NOERROR;
712 return *this;
713 }
714 size -= retsize;
715 buf += retsize;
716
717 m_i_streambuf->Read(buf, size);
718
719 return *this;
720 }
721
722 off_t wxBufferedInputStream::SeekI(off_t pos, wxSeekMode mode)
723 {
724 return m_i_streambuf->Seek(pos, mode);
725 }
726
727 off_t wxBufferedInputStream::TellI() const
728 {
729 return m_i_streambuf->Tell();
730 }
731
732 size_t wxBufferedInputStream::OnSysRead(void *buffer, size_t bufsize)
733 {
734 return m_parent_i_stream->Read(buffer, bufsize).LastRead();
735 }
736
737 off_t wxBufferedInputStream::OnSysSeek(off_t seek, wxSeekMode mode)
738 {
739 return m_parent_i_stream->SeekI(seek, mode);
740 }
741
742 off_t wxBufferedInputStream::OnSysTell() const
743 {
744 return m_parent_i_stream->TellI();
745 }
746
747 // ----------------------------------------------------------------------------
748 // wxBufferedOutputStream
749 // ----------------------------------------------------------------------------
750
751 wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& s)
752 : wxFilterOutputStream(s)
753 {
754 m_o_streambuf = new wxStreamBuffer(*this, wxStreamBuffer::write);
755 m_o_streambuf->SetBufferIO(1024);
756 }
757
758 wxBufferedOutputStream::~wxBufferedOutputStream()
759 {
760 delete m_o_streambuf;
761 }
762
763 wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
764 {
765 m_lastcount = 0;
766 m_o_streambuf->Write(buffer, size);
767 return *this;
768 }
769
770 off_t wxBufferedOutputStream::SeekO(off_t pos, wxSeekMode mode)
771 {
772 return m_o_streambuf->Seek(pos, mode);
773 }
774
775 off_t wxBufferedOutputStream::TellO() const
776 {
777 return m_o_streambuf->Tell();
778 }
779
780 void wxBufferedOutputStream::Sync()
781 {
782 m_o_streambuf->FlushBuffer();
783 m_parent_o_stream->Sync();
784 }
785
786 size_t wxBufferedOutputStream::OnSysWrite(const void *buffer, size_t bufsize)
787 {
788 return m_parent_o_stream->Write(buffer, bufsize).LastWrite();
789 }
790
791 off_t wxBufferedOutputStream::OnSysSeek(off_t seek, wxSeekMode mode)
792 {
793 return m_parent_o_stream->SeekO(seek, mode);
794 }
795
796 off_t wxBufferedOutputStream::OnSysTell() const
797 {
798 return m_parent_o_stream->TellO();
799 }
800
801 // ----------------------------------------------------------------------------
802 // Some IOManip function
803 // ----------------------------------------------------------------------------
804
805 wxOutputStream& wxEndL(wxOutputStream& stream)
806 {
807 #ifdef __MSW__
808 return stream.Write("\r\n", 2);
809 #else
810 #ifdef __WXMAC__
811 return stream.Write("\r", 1);
812 #else
813 return stream.Write("\n", 1);
814 #endif
815 #endif
816 }
817
818 #endif
819 // wxUSE_STREAMS