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 #include <ctype.h>
  19 #include <wx/stream.h>
  20 #include <wx/datstrm.h>
  21 #include <wx/objstrm.h>
  22
  23 #ifdef __BORLANDC__
  24 #pragma hdrstop
  25 #endif
  26
  27 // ----------------------------------------------------------------------------
  28 // wxStreamBuffer
  29 // ----------------------------------------------------------------------------
  30
  31 wxStreamBuffer::wxStreamBuffer(wxInputStream& i_stream)
  32   : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
  33     m_buffer_size(0), m_istream(&i_stream), m_ostream(NULL)
  34 {
  35 }
  36
  37 wxStreamBuffer::wxStreamBuffer(wxOutputStream& o_stream)
  38   : m_buffer_start(NULL), m_buffer_end(NULL), m_buffer_pos(NULL),
  39     m_buffer_size(0), m_istream(NULL), m_ostream(&o_stream)
  40 {
  41 }
  42
  43 wxStreamBuffer::~wxStreamBuffer()
  44 {
  45   wxDELETEA(m_buffer_start);
  46 }
  47
  48 void wxStreamBuffer::WriteBack(char c)
  49 {
  50   if (m_ostream)
  51     return;
  52
  53   // Assume that if we write "back" we have read a few bytes: so we have some
  54   // space.
  55   if (m_buffer_pos == m_buffer_start)
  56     return;
  57
  58   m_buffer_pos--;
  59   *m_buffer_pos = c;
  60 }
  61
  62 void wxStreamBuffer::SetBufferIO(char *buffer_start, char *buffer_end)
  63 {
  64   size_t ret;
  65
  66   m_buffer_start = buffer_start;
  67   m_buffer_end   = buffer_end;
  68
  69   m_buffer_size = m_buffer_end-m_buffer_start;
  70
  71   if (m_istream) {
  72     ret = m_istream->DoRead(m_buffer_start, m_buffer_size);
  73     m_buffer_end = m_buffer_start + ret;
  74   }
  75   m_buffer_pos = m_buffer_start;
  76 }
  77
  78 void wxStreamBuffer::SetBufferIO(size_t bufsize)
  79 {
  80   char *b_start;
  81
  82   wxDELETE(m_buffer_start);
  83
  84   if (!bufsize) {
  85     m_buffer_start = NULL;
  86     m_buffer_end = NULL;
  87     m_buffer_pos = NULL;
  88     m_buffer_size = 0;
  89     return;
  90   }
  91
  92   b_start = new char[bufsize];
  93
  94   SetBufferIO(b_start, b_start + bufsize);
  95 }
  96
  97 void wxStreamBuffer::ResetBuffer()
  98 {
  99   if (m_istream)
 100     m_buffer_pos = m_buffer_end;
 101   else
 102     m_buffer_pos = m_buffer_start;
 103 }
 104
 105 void wxStreamBuffer::Read(void *buffer, size_t size)
 106 {
 107   wxASSERT(m_istream != NULL);
 108
 109   // ------------------
 110   // Buffering disabled
 111   // ------------------
 112
 113   if (!m_buffer_size) {
 114     m_istream->m_lastread = m_istream->DoRead(buffer, size);
 115     return;
 116   }
 117
 118   // -----------------
 119   // Buffering enabled
 120   // -----------------
 121   size_t buf_left, orig_size = size;
 122   size_t read_ret;
 123
 124   while (size > 0) {
 125     buf_left = m_buffer_end - m_buffer_pos;
 126
 127     // First case: the requested buffer is larger than the stream buffer,
 128     //             we split
 129     if (size > buf_left) {
 130       memcpy(buffer, m_buffer_pos, buf_left);
 131       size -= buf_left;
 132       buffer = (char *)buffer + buf_left; // ANSI C++ violation.
 133
 134       read_ret = m_istream->DoRead(m_buffer_start, m_buffer_size);
 135
 136       // Read failed: EOF
 137       if (read_ret == 0) {
 138         m_istream->m_lastread = orig_size-size;
 139         m_istream->m_eof = TRUE;
 140         m_buffer_pos = m_buffer_end = m_buffer_start;
 141         return;
 142       } else {
 143         m_buffer_end = m_buffer_start+read_ret;
 144         m_buffer_pos = m_buffer_start;
 145       }
 146     } else {
 147
 148       // Second case: we just copy from the stream buffer.
 149       memcpy(buffer, m_buffer_pos, size);
 150       m_buffer_pos += size;
 151       break;
 152     }
 153   }
 154   m_istream->m_lastread = orig_size;
 155 }
 156
 157 void wxStreamBuffer::Write(const void *buffer, size_t size)
 158 {
 159   wxASSERT(m_ostream != NULL);
 160
 161   // ------------------
 162   // Buffering disabled
 163   // ------------------
 164
 165   if (!m_buffer_size) {
 166     m_ostream->m_lastwrite = m_ostream->DoWrite(buffer, size);
 167     return;
 168   }
 169
 170   // ------------------
 171   // Buffering enabled
 172   // ------------------
 173
 174   size_t buf_left, orig_size = size;
 175   size_t write_ret;
 176
 177   while (size > 0) {
 178     buf_left = m_buffer_end - m_buffer_pos;
 179
 180     // First case: the buffer to write is larger than the stream buffer,
 181     //             we split it
 182     if (size > buf_left) {
 183       memcpy(m_buffer_pos, buffer, buf_left);
 184       size -= buf_left;
 185       buffer = (char *)buffer + buf_left; // ANSI C++ violation.
 186
 187       write_ret = m_ostream->DoWrite(m_buffer_start, m_buffer_size);
 188       if (write_ret != m_buffer_size) {
 189         m_ostream->m_bad = TRUE;
 190         m_ostream->m_lastwrite = orig_size-size;
 191         m_buffer_pos = m_buffer_end = m_buffer_start;
 192         return;
 193       }
 194       m_buffer_pos = m_buffer_start;
 195
 196     } else {
 197
 198       // Second case: just copy it in the stream buffer.
 199
 200       memcpy(m_buffer_pos, buffer, size);
 201       m_buffer_pos += size;
 202       break;
 203     }
 204   }
 205   m_ostream->m_lastwrite = orig_size;
 206 }
 207
 208 // ----------------------------------------------------------------------------
 209 // wxInputStream
 210 // ----------------------------------------------------------------------------
 211
 212 wxInputStream::wxInputStream()
 213 {
 214   m_i_destroybuf = TRUE;
 215   m_i_streambuf = new wxStreamBuffer(*this);
 216   m_eof = FALSE;
 217   m_lastread = 0;
 218 }
 219
 220 wxInputStream::wxInputStream(wxStreamBuffer *buffer)
 221 {
 222   m_i_destroybuf = FALSE;
 223   m_i_streambuf = buffer;
 224   m_eof = FALSE;
 225   m_lastread = 0;
 226 }
 227
 228 wxInputStream::~wxInputStream()
 229 {
 230   if (m_i_destroybuf)
 231     delete m_i_streambuf;
 232 }
 233
 234 char wxInputStream::GetC()
 235 {
 236   char c;
 237   m_i_streambuf->Read(&c, 1);
 238   return c;
 239 }
 240
 241 wxInputStream& wxInputStream::Read(void *buffer, size_t size)
 242 {
 243   m_i_streambuf->Read(buffer, size);
 244   // wxStreamBuffer sets all variables for us
 245   return *this;
 246 }
 247
 248 #define BUF_TEMP_SIZE 10000
 249
 250 wxInputStream& wxInputStream::Read(wxOutputStream& stream_out)
 251 {
 252   char buf[BUF_TEMP_SIZE];
 253   size_t bytes_read = BUF_TEMP_SIZE;
 254
 255   while (bytes_read == BUF_TEMP_SIZE && !stream_out.Bad()) {
 256     bytes_read = Read(buf, bytes_read).LastRead();
 257
 258     stream_out.Write(buf, bytes_read);
 259   }
 260   return *this;
 261 }
 262
 263 wxInputStream& wxInputStream::operator>>(wxString& line)
 264 {
 265   wxDataInputStream s(*this);
 266
 267   line = s.ReadLine();
 268   return *this;
 269 }
 270
 271 wxInputStream& wxInputStream::operator>>(char& c)
 272 {
 273   c = GetC();
 274   return *this;
 275 }
 276
 277 wxInputStream& wxInputStream::operator>>(short& i)
 278 {
 279   long l;
 280
 281   *this >> l;
 282   i = (short)l;
 283   return *this;
 284 }
 285
 286 wxInputStream& wxInputStream::operator>>(int& i)
 287 {
 288   long l;
 289
 290   *this >> l;
 291   i = (short)l;
 292   return *this;
 293 }
 294
 295 wxInputStream& wxInputStream::operator>>(long& i)
 296 {
 297   /* I only implemented a simple integer parser */
 298   int c, sign;
 299
 300   while (isspace( c = GetC() ) )
 301      /* Do nothing */ ;
 302
 303   i = 0;
 304   if (! (c == '-' || isdigit(c)) ) {
 305     InputStreamBuffer()->WriteBack(c);
 306     return *this;
 307   }
 308
 309   if (c == '-') {
 310     sign = -1;
 311     c = GetC();
 312   } else
 313     sign = 1;
 314
 315   while (isdigit(c)) {
 316     i = i*10 + c;
 317     c = GetC();
 318   }
 319
 320   i *= sign;
 321
 322   return *this;
 323 }
 324
 325 wxInputStream& wxInputStream::operator>>(float& f)
 326 {
 327   /* I only implemented a simple float parser */
 328   int c, sign;
 329
 330   while (isspace( c = GetC() ) )
 331      /* Do nothing */ ;
 332
 333   f = 0.0;
 334   if (! (c == '-' || isdigit(c)) ) {
 335     InputStreamBuffer()->WriteBack(c);
 336     return *this;
 337   }
 338
 339   if (c == '-') {
 340     sign = -1;
 341     c = GetC();
 342   } else
 343     sign = 1;
 344
 345   while (isdigit(c)) {
 346     f = f*10 + c;
 347     c = GetC();
 348   }
 349
 350   if (c == '.') {
 351     float f_multiplicator = 0.1;
 352     c = GetC();
 353
 354     while (isdigit(c)) {
 355       f += c*f_multiplicator;
 356       f_multiplicator /= 10;
 357       c = GetC();
 358     }
 359   }
 360
 361   f *= sign;
 362
 363   return *this;
 364 }
 365
 366 wxInputStream& wxInputStream::operator>>(wxObject *& obj)
 367 {
 368   wxObjectInputStream obj_s(*this);
 369   obj = obj_s.LoadObject();
 370   return *this;
 371 }
 372
 373 off_t wxInputStream::SeekI(off_t pos, wxSeekMode mode)
 374 {
 375   off_t ret_off, diff, last_access;
 376
 377   last_access = m_i_streambuf->GetLastAccess();
 378
 379   switch (mode) {
 380   case wxFromStart:
 381     diff = DoTellInput() - pos;
 382     if ( diff < 0 || diff > last_access  ) {
 383       ret_off = DoSeekInput(pos, wxFromStart);
 384       m_i_streambuf->ResetBuffer();
 385       return ret_off;
 386     } else {
 387       m_i_streambuf->SetIntPosition(last_access - diff);
 388       return pos;
 389     }
 390   case wxFromCurrent:
 391     diff = pos + m_i_streambuf->GetIntPosition();
 392
 393     if ( (diff > last_access) || (diff < 0) ) {
 394       ret_off = DoSeekInput(pos, wxFromCurrent);
 395       m_i_streambuf->ResetBuffer();
 396       return ret_off;
 397     } else {
 398       m_i_streambuf->SetIntPosition(diff);
 399       return pos;
 400     }
 401   case wxFromEnd:
 402     // Hard to compute: always seek to the requested position.
 403     ret_off = DoSeekInput(pos, wxFromEnd);
 404     m_i_streambuf->ResetBuffer();
 405     return ret_off;
 406   }
 407   return wxInvalidOffset;
 408 }
 409
 410 off_t wxInputStream::TellI() const
 411 {
 412   return DoTellInput() - m_i_streambuf->GetLastAccess() +
 413                          m_i_streambuf->GetIntPosition();
 414 }
 415
 416 // ----------------------------------------------------------------------------
 417 // wxOutputStream
 418 // ----------------------------------------------------------------------------
 419 wxOutputStream::wxOutputStream()
 420 {
 421   m_o_destroybuf = TRUE;
 422   m_o_streambuf = new wxStreamBuffer(*this);
 423   m_bad = FALSE;
 424   m_lastwrite = 0;
 425 }
 426
 427 wxOutputStream::wxOutputStream(wxStreamBuffer *buffer)
 428 {
 429   m_o_destroybuf = FALSE;
 430   m_o_streambuf = buffer;
 431   m_bad = FALSE;
 432   m_lastwrite = 0;
 433 }
 434
 435 wxOutputStream::~wxOutputStream()
 436 {
 437   if (m_o_destroybuf)
 438     delete m_o_streambuf;
 439 }
 440
 441 wxOutputStream& wxOutputStream::Write(const void *buffer, size_t size)
 442 {
 443   m_o_streambuf->Write(buffer, size);
 444   return *this;
 445 }
 446
 447 wxOutputStream& wxOutputStream::Write(wxInputStream& stream_in)
 448 {
 449   stream_in.Read(*this);
 450   return *this;
 451 }
 452
 453 off_t wxOutputStream::SeekO(off_t pos, wxSeekMode mode)
 454 {
 455   off_t ret_off;
 456
 457   switch (mode) {
 458   case wxFromStart:
 459     if ( (unsigned)abs (DoTellOutput()-pos) > m_o_streambuf->GetLastAccess()  ) {
 460       ret_off = DoSeekOutput(pos, wxFromStart);
 461       m_o_streambuf->ResetBuffer();
 462       return ret_off;
 463     } else {
 464       m_o_streambuf->SetIntPosition( DoTellOutput() - pos);
 465       return pos;
 466     }
 467   case wxFromCurrent:
 468     if ( ((unsigned)pos > m_o_streambuf->GetLastAccess()) || (pos < 0) ) {
 469       ret_off = DoSeekOutput(pos, wxFromCurrent);
 470       m_o_streambuf->ResetBuffer();
 471       return ret_off;
 472     } else {
 473       m_o_streambuf->SetIntPosition(pos);
 474       return pos;
 475     }
 476   case wxFromEnd:
 477     // Hard to compute: always seek to the requested position.
 478     ret_off = DoSeekOutput(pos, wxFromEnd);
 479     m_o_streambuf->ResetBuffer();
 480     return ret_off;
 481   }
 482   return wxInvalidOffset;
 483 }
 484
 485 off_t wxOutputStream::TellO() const
 486 {
 487   return DoTellOutput() - m_o_streambuf->GetLastAccess()
 488                         + m_o_streambuf->GetIntPosition();
 489 }
 490
 491 void wxOutputStream::Sync()
 492 {
 493   DoWrite(m_o_streambuf->GetBufferStart(), m_o_streambuf->GetIntPosition());
 494
 495   m_o_streambuf->ResetBuffer();
 496 }
 497
 498 wxOutputStream& wxOutputStream::operator<<(const char *string)
 499 {
 500   return Write(string, strlen(string));
 501 }
 502
 503 wxOutputStream& wxOutputStream::operator<<(wxString& string)
 504 {
 505   return Write(string, string.Len());
 506 }
 507
 508 wxOutputStream& wxOutputStream::operator<<(char c)
 509 {
 510   return Write(&c, 1);
 511 }
 512
 513 wxOutputStream& wxOutputStream::operator<<(short i)
 514 {
 515   wxString strint;
 516
 517   strint.Printf("%i", i);
 518   return Write(strint, strint.Len());
 519 }
 520
 521 wxOutputStream& wxOutputStream::operator<<(int i)
 522 {
 523   wxString strint;
 524
 525   strint.Printf("%i", i);
 526   return Write(strint, strint.Len());
 527 }
 528
 529 wxOutputStream& wxOutputStream::operator<<(long i)
 530 {
 531   wxString strlong;
 532
 533   strlong.Printf("%i", i);
 534   return Write((const char *)strlong, strlong.Len());
 535 }
 536
 537 wxOutputStream& wxOutputStream::operator<<(double f)
 538 {
 539   wxString strfloat;
 540
 541   strfloat.Printf("%f", f);
 542   return Write(strfloat, strfloat.Len());
 543 }
 544
 545 wxOutputStream& wxOutputStream::operator<<(wxObject& obj)
 546 {
 547   wxObjectOutputStream obj_s(*this);
 548   obj_s.SaveObject(obj);
 549   return *this;
 550 }
 551
 552 // ----------------------------------------------------------------------------
 553 // wxFilterInputStream
 554 // ----------------------------------------------------------------------------
 555 wxFilterInputStream::wxFilterInputStream(wxInputStream& stream)
 556   : wxInputStream(NULL)
 557 {
 558   m_parent_i_stream = &stream;
 559   m_i_streambuf = stream.InputStreamBuffer();
 560 }
 561
 562 wxFilterInputStream::~wxFilterInputStream()
 563 {
 564 }
 565
 566 size_t wxFilterInputStream::DoRead(void *buffer, size_t size)
 567 {
 568   return m_parent_i_stream->Read(buffer, size).LastRead();
 569 }
 570
 571 off_t wxFilterInputStream::DoSeekInput(off_t pos, wxSeekMode mode)
 572 {
 573   return m_parent_i_stream->SeekI(pos, mode);
 574 }
 575
 576 off_t wxFilterInputStream::DoTellInput() const
 577 {
 578   return m_parent_i_stream->TellI();
 579 }
 580
 581
 582 // ----------------------------------------------------------------------------
 583 // wxFilterOutputStream
 584 // ----------------------------------------------------------------------------
 585 wxFilterOutputStream::wxFilterOutputStream(wxOutputStream& stream)
 586   : wxOutputStream(NULL)
 587 {
 588   m_parent_o_stream = &stream;
 589   m_o_streambuf = stream.OutputStreamBuffer();
 590 }
 591
 592 wxFilterOutputStream::~wxFilterOutputStream()
 593 {
 594 }
 595
 596 size_t wxFilterOutputStream::DoWrite(const void *buffer, size_t size)
 597 {
 598   return m_parent_o_stream->Write(buffer, size).LastWrite();
 599 }
 600
 601 off_t wxFilterOutputStream::DoSeekOutput(off_t pos, wxSeekMode mode)
 602 {
 603   return m_parent_o_stream->SeekO(pos, mode);
 604 }
 605
 606 off_t wxFilterOutputStream::DoTellOutput() const
 607 {
 608   return m_parent_o_stream->TellO();
 609 }
 610
 611 // ----------------------------------------------------------------------------
 612 // Some IOManip function
 613 // ----------------------------------------------------------------------------
 614
 615 wxOutputStream& wxEndL(wxOutputStream& stream)
 616 {
 617 #ifdef __MSW__
 618   return stream.Write("\r\n", 2);
 619 #else
 620   return stream.Write("\n", 1);
 621 #endif
 622 }