No changes, just spelling corrections in the comments.
[wxWidgets.git] / src / common / stream.cpp
1 /////////////////////////////////////////////////////////////////////////////
2 // Name: src/common/stream.cpp
3 // Purpose: wxStream base classes
4 // Author: Guilhem Lavaux
5 // Modified by: VZ (23.11.00) to fix realloc()ing new[]ed memory,
6 // general code review
7 // Created: 11/07/98
8 // RCS-ID: $Id$
9 // Copyright: (c) Guilhem Lavaux
10 // Licence: wxWindows licence
11 /////////////////////////////////////////////////////////////////////////////
12
13 // ============================================================================
14 // declarations
15 // ============================================================================
16
17 // ----------------------------------------------------------------------------
18 // headers
19 // ----------------------------------------------------------------------------
20
21 // For compilers that support precompilation, includes "wx.h".
22 #include "wx/wxprec.h"
23
24 #ifdef __BORLANDC__
25 #pragma hdrstop
26 #endif
27
28 #if wxUSE_STREAMS
29
30 #include "wx/stream.h"
31
32 #ifndef WX_PRECOMP
33 #include "wx/log.h"
34 #endif
35
36 #include <ctype.h>
37 #include "wx/datstrm.h"
38 #include "wx/textfile.h"
39 #include "wx/scopeguard.h"
40
41 // ----------------------------------------------------------------------------
42 // constants
43 // ----------------------------------------------------------------------------
44
45 // the temporary buffer size used when copying from stream to stream
46 #define BUF_TEMP_SIZE 4096
47
48 // ============================================================================
49 // implementation
50 // ============================================================================
51
52 // ----------------------------------------------------------------------------
53 // wxStreamBuffer
54 // ----------------------------------------------------------------------------
55
56 void wxStreamBuffer::SetError(wxStreamError err)
57 {
58 if ( m_stream && m_stream->m_lasterror == wxSTREAM_NO_ERROR )
59 m_stream->m_lasterror = err;
60 }
61
62 void wxStreamBuffer::InitBuffer()
63 {
64 m_buffer_start =
65 m_buffer_end =
66 m_buffer_pos = NULL;
67
68 // if we are going to allocate the buffer, we should free it later as well
69 m_destroybuf = true;
70 }
71
72 void wxStreamBuffer::Init()
73 {
74 InitBuffer();
75
76 m_fixed = true;
77 }
78
79 void wxStreamBuffer::InitWithStream(wxStreamBase& stream, BufMode mode)
80 {
81 Init();
82
83 m_stream = &stream;
84 m_mode = mode;
85
86 m_flushable = true;
87 }
88
89 wxStreamBuffer::wxStreamBuffer(BufMode mode)
90 {
91 Init();
92
93 m_stream = NULL;
94 m_mode = mode;
95
96 m_flushable = false;
97 }
98
99 wxStreamBuffer::wxStreamBuffer(const wxStreamBuffer& buffer)
100 {
101 // doing this has big chances to lead to a crash when the source buffer is
102 // destroyed (otherwise assume the caller knows what he does)
103 wxASSERT_MSG( !buffer.m_destroybuf,
104 wxT("it's a bad idea to copy this buffer") );
105
106 m_buffer_start = buffer.m_buffer_start;
107 m_buffer_end = buffer.m_buffer_end;
108 m_buffer_pos = buffer.m_buffer_pos;
109 m_fixed = buffer.m_fixed;
110 m_flushable = buffer.m_flushable;
111 m_stream = buffer.m_stream;
112 m_mode = buffer.m_mode;
113 m_destroybuf = false;
114 }
115
116 void wxStreamBuffer::FreeBuffer()
117 {
118 if ( m_destroybuf )
119 {
120 free(m_buffer_start);
121 m_buffer_start = NULL;
122 }
123 }
124
125 wxStreamBuffer::~wxStreamBuffer()
126 {
127 FreeBuffer();
128 }
129
130 wxInputStream *wxStreamBuffer::GetInputStream() const
131 {
132 return m_mode == write ? NULL : (wxInputStream *)m_stream;
133 }
134
135 wxOutputStream *wxStreamBuffer::GetOutputStream() const
136 {
137 return m_mode == read ? NULL : (wxOutputStream *)m_stream;
138 }
139
140 void wxStreamBuffer::SetBufferIO(void *buffer_start,
141 void *buffer_end,
142 bool takeOwnership)
143 {
144 SetBufferIO(buffer_start, (char *)buffer_end - (char *)buffer_start,
145 takeOwnership);
146 }
147
148 void wxStreamBuffer::SetBufferIO(void *start,
149 size_t len,
150 bool takeOwnership)
151 {
152 // start by freeing the old buffer
153 FreeBuffer();
154
155 m_buffer_start = (char *)start;
156 m_buffer_end = m_buffer_start + len;
157
158 // if we own it, we free it
159 m_destroybuf = takeOwnership;
160
161 ResetBuffer();
162 }
163
164 void wxStreamBuffer::SetBufferIO(size_t bufsize)
165 {
166 if ( bufsize )
167 {
168 // this will free the old buffer and allocate the new one
169 SetBufferIO(malloc(bufsize), bufsize, true /* take ownership */);
170 }
171 else // no buffer size => no buffer
172 {
173 // still free the old one
174 FreeBuffer();
175 InitBuffer();
176 }
177 }
178
179 void wxStreamBuffer::ResetBuffer()
180 {
181 if ( m_stream )
182 {
183 m_stream->Reset();
184 m_stream->m_lastcount = 0;
185 }
186
187 m_buffer_pos = m_mode == read && m_flushable
188 ? m_buffer_end
189 : m_buffer_start;
190 }
191
192 void wxStreamBuffer::Truncate()
193 {
194 size_t new_size = m_buffer_pos - m_buffer_start;
195 if ( m_buffer_pos == m_buffer_end )
196 return;
197
198 if ( !new_size )
199 {
200 FreeBuffer();
201 InitBuffer();
202 return;
203 }
204
205 char *new_start = (char *)realloc(m_buffer_start, new_size);
206 wxCHECK_RET( new_size, wxT("shrinking buffer shouldn't fail") );
207
208 m_buffer_start = new_start;
209 m_buffer_end = m_buffer_start + new_size;
210 m_buffer_pos = m_buffer_end;
211 }
212
213 // fill the buffer with as much data as possible (only for read buffers)
214 bool wxStreamBuffer::FillBuffer()
215 {
216 wxInputStream *inStream = GetInputStream();
217
218 // It's legal to have no stream, so we don't complain about it just return false
219 if ( !inStream )
220 return false;
221
222 size_t count = inStream->OnSysRead(GetBufferStart(), GetBufferSize());
223 if ( !count )
224 return false;
225
226 m_buffer_end = m_buffer_start + count;
227 m_buffer_pos = m_buffer_start;
228
229 return true;
230 }
231
232 // write the buffer contents to the stream (only for write buffers)
233 bool wxStreamBuffer::FlushBuffer()
234 {
235 wxCHECK_MSG( m_flushable, false, wxT("can't flush this buffer") );
236
237 // FIXME: what is this check for? (VZ)
238 if ( m_buffer_pos == m_buffer_start )
239 return false;
240
241 wxOutputStream *outStream = GetOutputStream();
242
243 wxCHECK_MSG( outStream, false, wxT("should have a stream in wxStreamBuffer") );
244
245 size_t current = m_buffer_pos - m_buffer_start;
246 size_t count = outStream->OnSysWrite(m_buffer_start, current);
247 if ( count != current )
248 return false;
249
250 m_buffer_pos = m_buffer_start;
251
252 return true;
253 }
254
255 size_t wxStreamBuffer::GetDataLeft()
256 {
257 /* Why is this done? RR. */
258 if ( m_buffer_pos == m_buffer_end && m_flushable)
259 FillBuffer();
260
261 return GetBytesLeft();
262 }
263
264 // copy up to size bytes from our buffer into the provided one
265 void wxStreamBuffer::GetFromBuffer(void *buffer, size_t size)
266 {
267 // don't get more bytes than left in the buffer
268 size_t left = GetBytesLeft();
269
270 if ( size > left )
271 size = left;
272
273 memcpy(buffer, m_buffer_pos, size);
274 m_buffer_pos += size;
275 }
276
277 // copy the contents of the provided buffer into this one
278 void wxStreamBuffer::PutToBuffer(const void *buffer, size_t size)
279 {
280 size_t left = GetBytesLeft();
281
282 if ( size > left )
283 {
284 if ( m_fixed )
285 {
286 // we can't realloc the buffer, so just copy what we can
287 size = left;
288 }
289 else // !m_fixed
290 {
291 // realloc the buffer to have enough space for the data
292 if ( m_buffer_pos + size > m_buffer_end )
293 {
294 size_t delta = m_buffer_pos - m_buffer_start;
295 size_t new_size = delta + size;
296
297 char *startOld = m_buffer_start;
298 m_buffer_start = (char *)realloc(m_buffer_start, new_size);
299 if ( !m_buffer_start )
300 {
301 // don't leak memory if realloc() failed
302 m_buffer_start = startOld;
303
304 // what else can we do?
305 return;
306 }
307
308 // adjust the pointers invalidated by realloc()
309 m_buffer_pos = m_buffer_start + delta;
310 m_buffer_end = m_buffer_start + new_size;
311 } // else: the buffer is big enough
312 }
313 }
314
315 memcpy(m_buffer_pos, buffer, size);
316 m_buffer_pos += size;
317 }
318
319 void wxStreamBuffer::PutChar(char c)
320 {
321 wxOutputStream *outStream = GetOutputStream();
322
323 wxCHECK_RET( outStream, wxT("should have a stream in wxStreamBuffer") );
324
325 // if we don't have buffer at all, just forward this call to the stream,
326 if ( !HasBuffer() )
327 {
328 outStream->OnSysWrite(&c, sizeof(c));
329 }
330 else
331 {
332 // otherwise check we have enough space left
333 if ( !GetDataLeft() && !FlushBuffer() )
334 {
335 // we don't
336 SetError(wxSTREAM_WRITE_ERROR);
337 }
338 else
339 {
340 PutToBuffer(&c, sizeof(c));
341 m_stream->m_lastcount = 1;
342 }
343 }
344 }
345
346 char wxStreamBuffer::Peek()
347 {
348 wxCHECK_MSG( m_stream && HasBuffer(), 0,
349 wxT("should have the stream and the buffer in wxStreamBuffer") );
350
351 if ( !GetDataLeft() )
352 {
353 SetError(wxSTREAM_READ_ERROR);
354 return 0;
355 }
356
357 char c;
358 GetFromBuffer(&c, sizeof(c));
359 m_buffer_pos--;
360
361 return c;
362 }
363
364 char wxStreamBuffer::GetChar()
365 {
366 wxInputStream *inStream = GetInputStream();
367
368 wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );
369
370 char c;
371 if ( !HasBuffer() )
372 {
373 inStream->OnSysRead(&c, sizeof(c));
374 }
375 else
376 {
377 if ( !GetDataLeft() )
378 {
379 SetError(wxSTREAM_READ_ERROR);
380 c = 0;
381 }
382 else
383 {
384 GetFromBuffer(&c, sizeof(c));
385 m_stream->m_lastcount = 1;
386 }
387 }
388
389 return c;
390 }
391
392 size_t wxStreamBuffer::Read(void *buffer, size_t size)
393 {
394 wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be used") );
395
396 /* Clear buffer first */
397 memset(buffer, 0x00, size);
398
399 // lasterror is reset before all new IO calls
400 if ( m_stream )
401 m_stream->Reset();
402
403 size_t readBytes;
404 if ( !HasBuffer() )
405 {
406 wxInputStream *inStream = GetInputStream();
407
408 wxCHECK_MSG( inStream, 0, wxT("should have a stream in wxStreamBuffer") );
409
410 readBytes = inStream->OnSysRead(buffer, size);
411 }
412 else // we have a buffer, use it
413 {
414 size_t orig_size = size;
415
416 while ( size > 0 )
417 {
418 size_t left = GetDataLeft();
419
420 // if the requested number of bytes if greater than the buffer
421 // size, read data in chunks
422 if ( size > left )
423 {
424 GetFromBuffer(buffer, left);
425 size -= left;
426 buffer = (char *)buffer + left;
427
428 if ( !FillBuffer() )
429 {
430 SetError(wxSTREAM_EOF);
431 break;
432 }
433 }
434 else // otherwise just do it in one gulp
435 {
436 GetFromBuffer(buffer, size);
437 size = 0;
438 }
439 }
440
441 readBytes = orig_size - size;
442 }
443
444 if ( m_stream )
445 m_stream->m_lastcount = readBytes;
446
447 return readBytes;
448 }
449
450 // this should really be called "Copy()"
451 size_t wxStreamBuffer::Read(wxStreamBuffer *dbuf)
452 {
453 wxCHECK_MSG( m_mode != write, 0, wxT("can't read from this buffer") );
454
455 char buf[BUF_TEMP_SIZE];
456 size_t nRead,
457 total = 0;
458
459 do
460 {
461 nRead = Read(buf, WXSIZEOF(buf));
462 if ( nRead )
463 {
464 nRead = dbuf->Write(buf, nRead);
465 total += nRead;
466 }
467 }
468 while ( nRead );
469
470 return total;
471 }
472
473 size_t wxStreamBuffer::Write(const void *buffer, size_t size)
474 {
475 wxASSERT_MSG( buffer, wxT("Warning: Null pointer is about to be send") );
476
477 if (m_stream)
478 {
479 // lasterror is reset before all new IO calls
480 m_stream->Reset();
481 }
482
483 size_t ret;
484
485 if ( !HasBuffer() && m_fixed )
486 {
487 wxOutputStream *outStream = GetOutputStream();
488
489 wxCHECK_MSG( outStream, 0, wxT("should have a stream in wxStreamBuffer") );
490
491 // no buffer, just forward the call to the stream
492 ret = outStream->OnSysWrite(buffer, size);
493 }
494 else // we [may] have a buffer, use it
495 {
496 size_t orig_size = size;
497
498 while ( size > 0 )
499 {
500 size_t left = GetBytesLeft();
501
502 // if the buffer is too large to fit in the stream buffer, split
503 // it in smaller parts
504 //
505 // NB: If stream buffer isn't fixed (as for wxMemoryOutputStream),
506 // we always go to the second case.
507 //
508 // FIXME: fine, but if it fails we should (re)try writing it by
509 // chunks as this will (hopefully) always work (VZ)
510
511 if ( size > left && m_fixed )
512 {
513 PutToBuffer(buffer, left);
514 size -= left;
515 buffer = (char *)buffer + left;
516
517 if ( !FlushBuffer() )
518 {
519 SetError(wxSTREAM_WRITE_ERROR);
520
521 break;
522 }
523
524 m_buffer_pos = m_buffer_start;
525 }
526 else // we can do it in one gulp
527 {
528 PutToBuffer(buffer, size);
529 size = 0;
530 }
531 }
532
533 ret = orig_size - size;
534 }
535
536 if (m_stream)
537 {
538 // i am not entirely sure what we do this for
539 m_stream->m_lastcount = ret;
540 }
541
542 return ret;
543 }
544
545 size_t wxStreamBuffer::Write(wxStreamBuffer *sbuf)
546 {
547 wxCHECK_MSG( m_mode != read, 0, wxT("can't write to this buffer") );
548 wxCHECK_MSG( sbuf->m_mode != write, 0, wxT("can't read from that buffer") );
549
550 char buf[BUF_TEMP_SIZE];
551 size_t nWrite,
552 total = 0;
553
554 do
555 {
556 size_t nRead = sbuf->Read(buf, WXSIZEOF(buf));
557 if ( nRead )
558 {
559 nWrite = Write(buf, nRead);
560 if ( nWrite < nRead )
561 {
562 // put back data we couldn't copy
563 wxInputStream *in_stream = (wxInputStream *)sbuf->GetStream();
564
565 in_stream->Ungetch(buf + nWrite, nRead - nWrite);
566 }
567
568 total += nWrite;
569 }
570 else
571 {
572 nWrite = 0;
573 }
574 }
575 while ( nWrite == WXSIZEOF(buf) );
576
577 return total;
578 }
579
580 wxFileOffset wxStreamBuffer::Seek(wxFileOffset pos, wxSeekMode mode)
581 {
582 wxFileOffset ret_off, diff;
583
584 wxFileOffset last_access = GetLastAccess();
585
586 if ( !m_flushable )
587 {
588 switch (mode)
589 {
590 case wxFromStart:
591 diff = pos;
592 break;
593
594 case wxFromCurrent:
595 diff = pos + GetIntPosition();
596 break;
597
598 case wxFromEnd:
599 diff = pos + last_access;
600 break;
601
602 default:
603 wxFAIL_MSG( wxT("invalid seek mode") );
604
605 return wxInvalidOffset;
606 }
607 if (diff < 0 || diff > last_access)
608 return wxInvalidOffset;
609 size_t int_diff = wx_truncate_cast(size_t, diff);
610 wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
611 SetIntPosition(int_diff);
612 return diff;
613 }
614
615 switch ( mode )
616 {
617 case wxFromStart:
618 // We'll try to compute an internal position later ...
619 ret_off = m_stream->OnSysSeek(pos, wxFromStart);
620 ResetBuffer();
621 return ret_off;
622
623 case wxFromCurrent:
624 diff = pos + GetIntPosition();
625
626 if ( (diff > last_access) || (diff < 0) )
627 {
628 // We must take into account the fact that we have read
629 // something previously.
630 ret_off = m_stream->OnSysSeek(diff-last_access, wxFromCurrent);
631 ResetBuffer();
632 return ret_off;
633 }
634 else
635 {
636 size_t int_diff = wx_truncate_cast(size_t, diff);
637 wxCHECK_MSG( (wxFileOffset)int_diff == diff, wxInvalidOffset, wxT("huge file not supported") );
638 SetIntPosition(int_diff);
639 return diff;
640 }
641
642 case wxFromEnd:
643 // Hard to compute: always seek to the requested position.
644 ret_off = m_stream->OnSysSeek(pos, wxFromEnd);
645 ResetBuffer();
646 return ret_off;
647 }
648
649 return wxInvalidOffset;
650 }
651
652 wxFileOffset wxStreamBuffer::Tell() const
653 {
654 wxFileOffset pos;
655
656 // ask the stream for position if we have a real one
657 if ( m_stream )
658 {
659 pos = m_stream->OnSysTell();
660 if ( pos == wxInvalidOffset )
661 return wxInvalidOffset;
662 }
663 else // no associated stream
664 {
665 pos = 0;
666 }
667
668 pos += GetIntPosition();
669
670 if ( m_mode == read && m_flushable )
671 pos -= GetLastAccess();
672
673 return pos;
674 }
675
676 // ----------------------------------------------------------------------------
677 // wxStreamBase
678 // ----------------------------------------------------------------------------
679
680 IMPLEMENT_ABSTRACT_CLASS(wxStreamBase, wxObject)
681
682 wxStreamBase::wxStreamBase()
683 {
684 m_lasterror = wxSTREAM_NO_ERROR;
685 m_lastcount = 0;
686 }
687
688 wxStreamBase::~wxStreamBase()
689 {
690 }
691
692 size_t wxStreamBase::GetSize() const
693 {
694 wxFileOffset length = GetLength();
695 if ( length == (wxFileOffset)wxInvalidOffset )
696 return 0;
697
698 const size_t len = wx_truncate_cast(size_t, length);
699 wxASSERT_MSG( len == length + size_t(0), wxT("large files not supported") );
700
701 return len;
702 }
703
704 wxFileOffset wxStreamBase::OnSysSeek(wxFileOffset WXUNUSED(seek), wxSeekMode WXUNUSED(mode))
705 {
706 return wxInvalidOffset;
707 }
708
709 wxFileOffset wxStreamBase::OnSysTell() const
710 {
711 return wxInvalidOffset;
712 }
713
714 // ----------------------------------------------------------------------------
715 // wxInputStream
716 // ----------------------------------------------------------------------------
717
718 IMPLEMENT_ABSTRACT_CLASS(wxInputStream, wxStreamBase)
719
720 wxInputStream::wxInputStream()
721 {
722 m_wback = NULL;
723 m_wbacksize =
724 m_wbackcur = 0;
725 }
726
727 wxInputStream::~wxInputStream()
728 {
729 free(m_wback);
730 }
731
732 bool wxInputStream::CanRead() const
733 {
734 // we don't know if there is anything to read or not and by default we
735 // prefer to be optimistic and try to read data unless we know for sure
736 // there is no more of it
737 return m_lasterror != wxSTREAM_EOF;
738 }
739
740 bool wxInputStream::Eof() const
741 {
742 // the only way the base class can know we're at EOF is when we'd already
743 // tried to read beyond it in which case last error is set accordingly
744 return GetLastError() == wxSTREAM_EOF;
745 }
746
747 char *wxInputStream::AllocSpaceWBack(size_t needed_size)
748 {
749 // get number of bytes left from previous wback buffer
750 size_t toget = m_wbacksize - m_wbackcur;
751
752 // allocate a buffer large enough to hold prev + new data
753 char *temp_b = (char *)malloc(needed_size + toget);
754
755 if (!temp_b)
756 return NULL;
757
758 // copy previous data (and free old buffer) if needed
759 if (m_wback)
760 {
761 memmove(temp_b + needed_size, m_wback + m_wbackcur, toget);
762 free(m_wback);
763 }
764
765 // done
766 m_wback = temp_b;
767 m_wbackcur = 0;
768 m_wbacksize = needed_size + toget;
769
770 return m_wback;
771 }
772
773 size_t wxInputStream::GetWBack(void *buf, size_t size)
774 {
775 wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used") );
776
777 /* Clear buffer first */
778 memset(buf, 0x00, size);
779
780 if (!m_wback)
781 return 0;
782
783 // how many bytes do we have in the buffer?
784 size_t toget = m_wbacksize - m_wbackcur;
785
786 if ( size < toget )
787 {
788 // we won't read everything
789 toget = size;
790 }
791
792 // copy the data from the cache
793 memcpy(buf, m_wback + m_wbackcur, toget);
794
795 m_wbackcur += toget;
796 if ( m_wbackcur == m_wbacksize )
797 {
798 // TODO: should we really free it here all the time? maybe keep it?
799 free(m_wback);
800 m_wback = NULL;
801 m_wbacksize = 0;
802 m_wbackcur = 0;
803 }
804
805 // return the number of bytes copied
806 return toget;
807 }
808
809 size_t wxInputStream::Ungetch(const void *buf, size_t bufsize)
810 {
811 wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be used in Ungetch()") );
812
813 if ( m_lasterror != wxSTREAM_NO_ERROR && m_lasterror != wxSTREAM_EOF )
814 {
815 // can't operate on this stream until the error is cleared
816 return 0;
817 }
818
819 char *ptrback = AllocSpaceWBack(bufsize);
820 if (!ptrback)
821 return 0;
822
823 // Eof() shouldn't return true any longer
824 if ( m_lasterror == wxSTREAM_EOF )
825 m_lasterror = wxSTREAM_NO_ERROR;
826
827 memcpy(ptrback, buf, bufsize);
828 return bufsize;
829 }
830
831 bool wxInputStream::Ungetch(char c)
832 {
833 return Ungetch(&c, sizeof(c)) != 0;
834 }
835
836 int wxInputStream::GetC()
837 {
838 unsigned char c;
839 Read(&c, sizeof(c));
840 return LastRead() ? c : wxEOF;
841 }
842
843 wxInputStream& wxInputStream::Read(void *buf, size_t size)
844 {
845 wxASSERT_MSG( buf, wxT("Warning: Null pointer is about to be read") );
846
847 char *p = (char *)buf;
848 m_lastcount = 0;
849
850 size_t read = GetWBack(buf, size);
851 for ( ;; )
852 {
853 size -= read;
854 m_lastcount += read;
855 p += read;
856
857 if ( !size )
858 {
859 // we read the requested amount of data
860 break;
861 }
862
863 if ( p != buf && !CanRead() )
864 {
865 // we have already read something and we would block in OnSysRead()
866 // now: don't do it but return immediately
867 break;
868 }
869
870 read = OnSysRead(p, size);
871 if ( !read )
872 {
873 // no more data available
874 break;
875 }
876 }
877
878 return *this;
879 }
880
881 char wxInputStream::Peek()
882 {
883 char c;
884 Read(&c, sizeof(c));
885 if (m_lasterror == wxSTREAM_NO_ERROR)
886 {
887 Ungetch(c);
888 return c;
889 }
890
891 return 0;
892 }
893
894 wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
895 {
896 size_t lastcount = 0;
897 char buf[BUF_TEMP_SIZE];
898
899 for ( ;; )
900 {
901 size_t bytes_read = Read(buf, WXSIZEOF(buf)).LastRead();
902 if ( !bytes_read )
903 break;
904
905 if ( stream_out.Write(buf, bytes_read).LastWrite() != bytes_read )
906 break;
907
908 lastcount += bytes_read;
909 }
910
911 m_lastcount = lastcount;
912
913 return *this;
914 }
915
916 wxFileOffset wxInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)
917 {
918 // RR: This code is duplicated in wxBufferedInputStream. This is
919 // not really a good design, but buffered stream are different
920 // from all others in that they handle two stream-related objects:
921 // the stream buffer and parent stream.
922
923 // I don't know whether it should be put as well in wxFileInputStream::OnSysSeek
924 if (m_lasterror==wxSTREAM_EOF)
925 m_lasterror=wxSTREAM_NO_ERROR;
926
927 // avoid unnecessary seek operations (optimization)
928 wxFileOffset currentPos = TellI(), size = GetLength();
929 if ((mode == wxFromStart && currentPos == pos) ||
930 (mode == wxFromCurrent && pos == 0) ||
931 (mode == wxFromEnd && size != wxInvalidOffset && currentPos == size-pos))
932 return currentPos;
933
934 if (!IsSeekable() && mode == wxFromCurrent && pos > 0)
935 {
936 // rather than seeking, we can just read data and discard it;
937 // this allows to forward-seek also non-seekable streams!
938 char buf[BUF_TEMP_SIZE];
939 size_t bytes_read;
940
941 // read chunks of BUF_TEMP_SIZE bytes until we reach the new position
942 for ( ; pos >= BUF_TEMP_SIZE; pos -= bytes_read)
943 {
944 bytes_read = Read(buf, WXSIZEOF(buf)).LastRead();
945 if ( m_lasterror != wxSTREAM_NO_ERROR )
946 return wxInvalidOffset;
947
948 wxASSERT(bytes_read == WXSIZEOF(buf));
949 }
950
951 // read the last 'pos' bytes
952 bytes_read = Read(buf, (size_t)pos).LastRead();
953 if ( m_lasterror != wxSTREAM_NO_ERROR )
954 return wxInvalidOffset;
955
956 wxASSERT(bytes_read == (size_t)pos);
957
958 // we should now have sought to the right position...
959 return TellI();
960 }
961
962 /* RR: A call to SeekI() will automatically invalidate any previous
963 call to Ungetch(), otherwise it would be possible to SeekI() to
964 one position, unread some bytes there, SeekI() to another position
965 and the data would be corrupted.
966
967 GRG: Could add code here to try to navigate within the wback
968 buffer if possible, but is it really needed? It would only work
969 when seeking in wxFromCurrent mode, else it would invalidate
970 anyway... */
971
972 if (m_wback)
973 {
974 wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
975
976 free(m_wback);
977 m_wback = NULL;
978 m_wbacksize = 0;
979 m_wbackcur = 0;
980 }
981
982 return OnSysSeek(pos, mode);
983 }
984
985 wxFileOffset wxInputStream::TellI() const
986 {
987 wxFileOffset pos = OnSysTell();
988
989 if (pos != wxInvalidOffset)
990 pos -= (m_wbacksize - m_wbackcur);
991
992 return pos;
993 }
994
995
996 // ----------------------------------------------------------------------------
997 // wxOutputStream
998 // ----------------------------------------------------------------------------
999
1000 IMPLEMENT_ABSTRACT_CLASS(wxOutputStream, wxStreamBase)
1001
1002 wxOutputStream::wxOutputStream()
1003 {
1004 }
1005
1006 wxOutputStream::~wxOutputStream()
1007 {
1008 }
1009
1010 size_t wxOutputStream::OnSysWrite(const void * WXUNUSED(buffer),
1011 size_t WXUNUSED(bufsize))
1012 {
1013 return 0;
1014 }
1015
1016 void wxOutputStream::PutC(char c)
1017 {
1018 Write(&c, sizeof(c));
1019 }
1020
1021 wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)
1022 {
1023 m_lastcount = OnSysWrite(buffer, size);
1024 return *this;
1025 }
1026
1027 wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
1028 {
1029 stream_in.Read(*this);
1030 return *this;
1031 }
1032
1033 wxFileOffset wxOutputStream::TellO() const
1034 {
1035 return OnSysTell();
1036 }
1037
1038 wxFileOffset wxOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)
1039 {
1040 return OnSysSeek(pos, mode);
1041 }
1042
1043 void wxOutputStream::Sync()
1044 {
1045 }
1046
1047
1048 // ----------------------------------------------------------------------------
1049 // wxCountingOutputStream
1050 // ----------------------------------------------------------------------------
1051
1052 IMPLEMENT_DYNAMIC_CLASS(wxCountingOutputStream, wxOutputStream)
1053
1054 wxCountingOutputStream::wxCountingOutputStream ()
1055 {
1056 m_currentPos = 0;
1057 }
1058
1059 wxFileOffset wxCountingOutputStream::GetLength() const
1060 {
1061 return m_lastcount;
1062 }
1063
1064 size_t wxCountingOutputStream::OnSysWrite(const void *WXUNUSED(buffer),
1065 size_t size)
1066 {
1067 m_currentPos += size;
1068 if (m_currentPos > m_lastcount)
1069 m_lastcount = m_currentPos;
1070
1071 return m_currentPos;
1072 }
1073
1074 wxFileOffset wxCountingOutputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
1075 {
1076 ssize_t new_pos = wx_truncate_cast(ssize_t, pos);
1077
1078 switch ( mode )
1079 {
1080 case wxFromStart:
1081 wxCHECK_MSG( (wxFileOffset)new_pos == pos, wxInvalidOffset, wxT("huge position not supported") );
1082 break;
1083
1084 case wxFromEnd:
1085 new_pos = m_lastcount + new_pos;
1086 wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_lastcount + pos), wxInvalidOffset, wxT("huge position not supported") );
1087 break;
1088
1089 case wxFromCurrent:
1090 new_pos = m_currentPos + new_pos;
1091 wxCHECK_MSG( (wxFileOffset)new_pos == (wxFileOffset)(m_currentPos + pos), wxInvalidOffset, wxT("huge position not supported") );
1092 break;
1093
1094 default:
1095 wxFAIL_MSG( wxT("invalid seek mode") );
1096 return wxInvalidOffset;
1097 }
1098
1099 m_currentPos = new_pos;
1100
1101 if (m_currentPos > m_lastcount)
1102 m_lastcount = m_currentPos;
1103
1104 return m_currentPos;
1105 }
1106
1107 wxFileOffset wxCountingOutputStream::OnSysTell() const
1108 {
1109 return m_currentPos;
1110 }
1111
1112 // ----------------------------------------------------------------------------
1113 // wxFilterInputStream
1114 // ----------------------------------------------------------------------------
1115
1116 IMPLEMENT_ABSTRACT_CLASS(wxFilterInputStream, wxInputStream)
1117
1118 wxFilterInputStream::wxFilterInputStream()
1119 : m_parent_i_stream(NULL),
1120 m_owns(false)
1121 {
1122 }
1123
1124 wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
1125 : m_parent_i_stream(&stream),
1126 m_owns(false)
1127 {
1128 }
1129
1130 wxFilterInputStream::wxFilterInputStream(wxInputStream *stream)
1131 : m_parent_i_stream(stream),
1132 m_owns(true)
1133 {
1134 }
1135
1136 wxFilterInputStream::~wxFilterInputStream()
1137 {
1138 if (m_owns)
1139 delete m_parent_i_stream;
1140 }
1141
1142 // ----------------------------------------------------------------------------
1143 // wxFilterOutputStream
1144 // ----------------------------------------------------------------------------
1145
1146 IMPLEMENT_ABSTRACT_CLASS(wxFilterOutputStream, wxOutputStream)
1147
1148 wxFilterOutputStream::wxFilterOutputStream()
1149 : m_parent_o_stream(NULL),
1150 m_owns(false)
1151 {
1152 }
1153
1154 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
1155 : m_parent_o_stream(&stream),
1156 m_owns(false)
1157 {
1158 }
1159
1160 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream *stream)
1161 : m_parent_o_stream(stream),
1162 m_owns(true)
1163 {
1164 }
1165
1166 bool wxFilterOutputStream::Close()
1167 {
1168 if (m_parent_o_stream && m_owns)
1169 return m_parent_o_stream->Close();
1170 else
1171 return true;
1172 }
1173
1174 wxFilterOutputStream::~wxFilterOutputStream()
1175 {
1176 if (m_owns)
1177 delete m_parent_o_stream;
1178 }
1179
1180 // ----------------------------------------------------------------------------
1181 // wxFilterClassFactoryBase
1182 // ----------------------------------------------------------------------------
1183
1184 IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactoryBase, wxObject)
1185
1186 wxString wxFilterClassFactoryBase::PopExtension(const wxString& location) const
1187 {
1188 return location.substr(0, FindExtension(location));
1189 }
1190
1191 wxString::size_type wxFilterClassFactoryBase::FindExtension(
1192 const wxString& location) const
1193 {
1194 for (const wxChar *const *p = GetProtocols(wxSTREAM_FILEEXT); *p; p++)
1195 {
1196 if ( location.EndsWith(*p) )
1197 return location.length() - wxStrlen(*p);
1198 }
1199
1200 return wxString::npos;
1201 }
1202
1203 bool wxFilterClassFactoryBase::CanHandle(const wxString& protocol,
1204 wxStreamProtocolType type) const
1205 {
1206 if (type == wxSTREAM_FILEEXT)
1207 return FindExtension(protocol) != wxString::npos;
1208 else
1209 for (const wxChar *const *p = GetProtocols(type); *p; p++)
1210 if (protocol == *p)
1211 return true;
1212
1213 return false;
1214 }
1215
1216 // ----------------------------------------------------------------------------
1217 // wxFilterClassFactory
1218 // ----------------------------------------------------------------------------
1219
1220 IMPLEMENT_ABSTRACT_CLASS(wxFilterClassFactory, wxFilterClassFactoryBase)
1221
1222 wxFilterClassFactory *wxFilterClassFactory::sm_first = NULL;
1223
1224 void wxFilterClassFactory::Remove()
1225 {
1226 if (m_next != this)
1227 {
1228 wxFilterClassFactory **pp = &sm_first;
1229
1230 while (*pp != this)
1231 pp = &(*pp)->m_next;
1232
1233 *pp = m_next;
1234
1235 m_next = this;
1236 }
1237 }
1238
1239 // ----------------------------------------------------------------------------
1240 // wxBufferedInputStream
1241 // ----------------------------------------------------------------------------
1242
1243 namespace
1244 {
1245
1246 // helper function used for initializing the buffer used by
1247 // wxBufferedInput/OutputStream: it simply returns the provided buffer if it's
1248 // not NULL or creates a buffer of the given size otherwise
1249 template <typename T>
1250 wxStreamBuffer *
1251 CreateBufferIfNeeded(T& stream, wxStreamBuffer *buffer, size_t bufsize = 1024)
1252 {
1253 return buffer ? buffer : new wxStreamBuffer(bufsize, stream);
1254 }
1255
1256 } // anonymous namespace
1257
1258 wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
1259 wxStreamBuffer *buffer)
1260 : wxFilterInputStream(stream)
1261 {
1262 m_i_streambuf = CreateBufferIfNeeded(*this, buffer);
1263 }
1264
1265 wxBufferedInputStream::wxBufferedInputStream(wxInputStream& stream,
1266 size_t bufsize)
1267 : wxFilterInputStream(stream)
1268 {
1269 m_i_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);
1270 }
1271
1272 wxBufferedInputStream::~wxBufferedInputStream()
1273 {
1274 m_parent_i_stream->SeekI(-(wxFileOffset)m_i_streambuf->GetBytesLeft(),
1275 wxFromCurrent);
1276
1277 delete m_i_streambuf;
1278 }
1279
1280 char wxBufferedInputStream::Peek()
1281 {
1282 return m_i_streambuf->Peek();
1283 }
1284
1285 wxInputStream& wxBufferedInputStream::Read(void *buf, size_t size)
1286 {
1287 // reset the error flag
1288 Reset();
1289
1290 // first read from the already cached data
1291 m_lastcount = GetWBack(buf, size);
1292
1293 // do we have to read anything more?
1294 if ( m_lastcount < size )
1295 {
1296 size -= m_lastcount;
1297 buf = (char *)buf + m_lastcount;
1298
1299 // the call to wxStreamBuffer::Read() below may reset our m_lastcount
1300 // (but it also may not do it if the buffer is associated to another
1301 // existing stream and wasn't created by us), so save it
1302 size_t countOld = m_lastcount;
1303
1304 // the new count of the bytes read is the count of bytes read this time
1305 m_lastcount = m_i_streambuf->Read(buf, size);
1306
1307 // plus those we had read before
1308 m_lastcount += countOld;
1309 }
1310
1311 return *this;
1312 }
1313
1314 wxFileOffset wxBufferedInputStream::SeekI(wxFileOffset pos, wxSeekMode mode)
1315 {
1316 // RR: Look at wxInputStream for comments.
1317
1318 if (m_lasterror==wxSTREAM_EOF)
1319 Reset();
1320
1321 if (m_wback)
1322 {
1323 wxLogDebug( wxT("Seeking in stream which has data written back to it.") );
1324
1325 free(m_wback);
1326 m_wback = NULL;
1327 m_wbacksize = 0;
1328 m_wbackcur = 0;
1329 }
1330
1331 return m_i_streambuf->Seek(pos, mode);
1332 }
1333
1334 wxFileOffset wxBufferedInputStream::TellI() const
1335 {
1336 wxFileOffset pos = m_i_streambuf->Tell();
1337
1338 if (pos != wxInvalidOffset)
1339 pos -= (m_wbacksize - m_wbackcur);
1340
1341 return pos;
1342 }
1343
1344 size_t wxBufferedInputStream::OnSysRead(void *buffer, size_t bufsize)
1345 {
1346 return m_parent_i_stream->Read(buffer, bufsize).LastRead();
1347 }
1348
1349 wxFileOffset wxBufferedInputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)
1350 {
1351 return m_parent_i_stream->SeekI(seek, mode);
1352 }
1353
1354 wxFileOffset wxBufferedInputStream::OnSysTell() const
1355 {
1356 return m_parent_i_stream->TellI();
1357 }
1358
1359 void wxBufferedInputStream::SetInputStreamBuffer(wxStreamBuffer *buffer)
1360 {
1361 wxCHECK_RET( buffer, wxT("wxBufferedInputStream needs buffer") );
1362
1363 delete m_i_streambuf;
1364 m_i_streambuf = buffer;
1365 }
1366
1367 // ----------------------------------------------------------------------------
1368 // wxBufferedOutputStream
1369 // ----------------------------------------------------------------------------
1370
1371 wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
1372 wxStreamBuffer *buffer)
1373 : wxFilterOutputStream(stream)
1374 {
1375 m_o_streambuf = CreateBufferIfNeeded(*this, buffer);
1376 }
1377
1378 wxBufferedOutputStream::wxBufferedOutputStream(wxOutputStream& stream,
1379 size_t bufsize)
1380 : wxFilterOutputStream(stream)
1381 {
1382 m_o_streambuf = CreateBufferIfNeeded(*this, NULL, bufsize);
1383 }
1384
1385 wxBufferedOutputStream::~wxBufferedOutputStream()
1386 {
1387 Sync();
1388 delete m_o_streambuf;
1389 }
1390
1391 bool wxBufferedOutputStream::Close()
1392 {
1393 Sync();
1394 return IsOk();
1395 }
1396
1397
1398 wxOutputStream& wxBufferedOutputStream::Write(const void *buffer, size_t size)
1399 {
1400 m_lastcount = 0;
1401 m_o_streambuf->Write(buffer, size);
1402 return *this;
1403 }
1404
1405 wxFileOffset wxBufferedOutputStream::SeekO(wxFileOffset pos, wxSeekMode mode)
1406 {
1407 Sync();
1408 return m_o_streambuf->Seek(pos, mode);
1409 }
1410
1411 wxFileOffset wxBufferedOutputStream::TellO() const
1412 {
1413 return m_o_streambuf->Tell();
1414 }
1415
1416 void wxBufferedOutputStream::Sync()
1417 {
1418 m_o_streambuf->FlushBuffer();
1419 m_parent_o_stream->Sync();
1420 }
1421
1422 size_t wxBufferedOutputStream::OnSysWrite(const void *buffer, size_t bufsize)
1423 {
1424 return m_parent_o_stream->Write(buffer, bufsize).LastWrite();
1425 }
1426
1427 wxFileOffset wxBufferedOutputStream::OnSysSeek(wxFileOffset seek, wxSeekMode mode)
1428 {
1429 return m_parent_o_stream->SeekO(seek, mode);
1430 }
1431
1432 wxFileOffset wxBufferedOutputStream::OnSysTell() const
1433 {
1434 return m_parent_o_stream->TellO();
1435 }
1436
1437 wxFileOffset wxBufferedOutputStream::GetLength() const
1438 {
1439 return m_parent_o_stream->GetLength() + m_o_streambuf->GetIntPosition();
1440 }
1441
1442 void wxBufferedOutputStream::SetOutputStreamBuffer(wxStreamBuffer *buffer)
1443 {
1444 wxCHECK_RET( buffer, wxT("wxBufferedOutputStream needs buffer") );
1445
1446 delete m_o_streambuf;
1447 m_o_streambuf = buffer;
1448 }
1449
1450 // ---------------------------------------------------------------------------
1451 // wxWrapperInputStream implementation
1452 // ---------------------------------------------------------------------------
1453
1454 wxWrapperInputStream::wxWrapperInputStream()
1455 {
1456 m_lasterror = wxSTREAM_READ_ERROR;
1457 }
1458
1459 wxWrapperInputStream::wxWrapperInputStream(wxInputStream& stream)
1460 : wxFilterInputStream(stream)
1461 {
1462 SynchronizeLastError();
1463 }
1464
1465 wxWrapperInputStream::wxWrapperInputStream(wxInputStream *stream)
1466 : wxFilterInputStream(stream)
1467 {
1468 if ( m_parent_i_stream )
1469 SynchronizeLastError();
1470 else
1471 m_lasterror = wxSTREAM_READ_ERROR;
1472 }
1473
1474 void wxWrapperInputStream::InitParentStream(wxInputStream& stream)
1475 {
1476 wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
1477
1478 m_parent_i_stream = &stream;
1479
1480 SynchronizeLastError();
1481 }
1482
1483 void wxWrapperInputStream::InitParentStream(wxInputStream* stream)
1484 {
1485 wxCHECK_RET( !m_parent_i_stream, "Can't init parent stream twice" );
1486
1487 m_parent_i_stream = stream;
1488
1489 if ( m_parent_i_stream )
1490 {
1491 m_owns = true;
1492
1493 SynchronizeLastError();
1494 }
1495 }
1496
1497 wxFileOffset wxWrapperInputStream::GetLength() const
1498 {
1499 wxCHECK_MSG(m_parent_i_stream, wxInvalidOffset, "Stream not valid");
1500
1501 wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
1502 return m_parent_i_stream->GetLength();
1503 }
1504
1505 bool wxWrapperInputStream::IsSeekable() const
1506 {
1507 wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
1508 return m_parent_i_stream->IsSeekable();
1509 }
1510
1511 size_t wxWrapperInputStream::OnSysRead(void *buffer, size_t size)
1512 {
1513 wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
1514
1515 wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
1516
1517 m_parent_i_stream->Read(buffer, size);
1518 return m_parent_i_stream->LastRead();
1519 }
1520
1521 wxFileOffset wxWrapperInputStream::OnSysSeek(wxFileOffset pos, wxSeekMode mode)
1522 {
1523 wxCHECK_MSG(IsSeekable(), false, "Stream not seekable");
1524
1525 wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
1526 return m_parent_i_stream->SeekI (pos, mode);
1527 }
1528
1529 wxFileOffset wxWrapperInputStream::OnSysTell() const
1530 {
1531 wxCHECK_MSG(m_parent_i_stream, false, "Stream not valid");
1532
1533 wxON_BLOCK_EXIT_THIS0(wxWrapperInputStream::SynchronizeLastError);
1534 return m_parent_i_stream->TellI();
1535 }
1536
1537 // ----------------------------------------------------------------------------
1538 // Some IOManip function
1539 // ----------------------------------------------------------------------------
1540
1541 wxOutputStream& wxEndL(wxOutputStream& stream)
1542 {
1543 static const wxChar *eol = wxTextFile::GetEOL();
1544
1545 return stream.Write(eol, wxStrlen(eol));
1546 }
1547
1548 #endif // wxUSE_STREAMS