src/common/ffile.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        ffile.cpp
   3 // Purpose:     wxFFile encapsulates "FILE *" IO stream
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     14.07.99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 // For compilers that support precompilation, includes "wx.h".
  21 #include "wx/wxprec.h"
  22
  23 #ifdef __BORLANDC__
  24   #pragma hdrstop
  25 #endif
  26
  27 #if wxUSE_FFILE
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/intl.h"
  31     #include "wx/log.h"
  32 #endif
  33
  34 #include "wx/ffile.h"
  35
  36 // ============================================================================
  37 // implementation
  38 // ============================================================================
  39
  40 // ----------------------------------------------------------------------------
  41 // seek and tell with large file support if available
  42 // ----------------------------------------------------------------------------
  43
  44 #ifdef HAVE_FSEEKO
  45 #   define wxFseek fseeko
  46 #   define wxFtell ftello
  47 #else
  48 #   define wxFseek fseek
  49 #   define wxFtell ftell
  50 #endif
  51
  52 // ----------------------------------------------------------------------------
  53 // opening the file
  54 // ----------------------------------------------------------------------------
  55
  56 wxFFile::wxFFile(const wxChar *filename, const wxChar *mode)
  57 {
  58     Detach();
  59
  60     (void)Open(filename, mode);
  61 }
  62
  63 bool wxFFile::Open(const wxChar *filename, const wxChar *mode)
  64 {
  65     wxASSERT_MSG( !m_fp, wxT("should close or detach the old file first") );
  66
  67     m_fp = wxFopen(filename, mode);
  68
  69     if ( !m_fp )
  70     {
  71         wxLogSysError(_("can't open file '%s'"), filename);
  72
  73         return false;
  74     }
  75
  76     m_name = filename;
  77
  78     return true;
  79 }
  80
  81 bool wxFFile::Close()
  82 {
  83     if ( IsOpened() )
  84     {
  85         if ( fclose(m_fp) != 0 )
  86         {
  87             wxLogSysError(_("can't close file '%s'"), m_name.c_str());
  88
  89             return false;
  90         }
  91
  92         Detach();
  93     }
  94
  95     return true;
  96 }
  97
  98 // ----------------------------------------------------------------------------
  99 // read/write
 100 // ----------------------------------------------------------------------------
 101
 102 bool wxFFile::ReadAll(wxString *str, wxMBConv& conv)
 103 {
 104     wxCHECK_MSG( str, false, wxT("invalid parameter") );
 105     wxCHECK_MSG( IsOpened(), false, wxT("can't read from closed file") );
 106     wxCHECK_MSG( Length() >= 0, false, wxT("invalid length") );
 107     size_t length = wx_truncate_cast(size_t, Length());
 108     wxCHECK_MSG( (wxFileOffset)length == Length(), false, wxT("huge file not supported") );
 109
 110     clearerr(m_fp);
 111
 112     wxCharBuffer buf(length + 1);
 113
 114     // note that real length may be less than file length for text files with DOS EOLs
 115     // ('\r's get dropped by CRT when reading which means that we have
 116     // realLen = fileLen - numOfLinesInTheFile)
 117     length = fread(buf.data(), sizeof(char), length, m_fp);
 118
 119     if ( Error() )
 120     {
 121         wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
 122
 123         return false;
 124     }
 125
 126     buf.data()[length] = 0;
 127     *str = wxString(buf, conv);
 128
 129     return true;
 130 }
 131
 132 size_t wxFFile::Read(void *pBuf, size_t nCount)
 133 {
 134     wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
 135     wxCHECK_MSG( IsOpened(), 0, wxT("can't read from closed file") );
 136
 137     size_t nRead = fread(pBuf, 1, nCount, m_fp);
 138     if ( (nRead < nCount) && Error() )
 139     {
 140         wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
 141     }
 142
 143     return nRead;
 144 }
 145
 146 size_t wxFFile::Write(const void *pBuf, size_t nCount)
 147 {
 148     wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
 149     wxCHECK_MSG( IsOpened(), 0, wxT("can't write to closed file") );
 150
 151     size_t nWritten = fwrite(pBuf, 1, nCount, m_fp);
 152     if ( nWritten < nCount )
 153     {
 154         wxLogSysError(_("Write error on file '%s'"), m_name.c_str());
 155     }
 156
 157     return nWritten;
 158 }
 159
 160 bool wxFFile::Flush()
 161 {
 162     if ( IsOpened() )
 163     {
 164         // fflush returns non-zero on error
 165         //
 166         if ( fflush(m_fp) )
 167         {
 168             wxLogSysError(_("failed to flush the file '%s'"), m_name.c_str());
 169
 170             return false;
 171         }
 172     }
 173
 174     return true;
 175 }
 176
 177 // ----------------------------------------------------------------------------
 178 // seeking
 179 // ----------------------------------------------------------------------------
 180
 181 bool wxFFile::Seek(wxFileOffset ofs, wxSeekMode mode)
 182 {
 183     wxCHECK_MSG( IsOpened(), false, wxT("can't seek on closed file") );
 184
 185     int origin;
 186     switch ( mode )
 187     {
 188         default:
 189             wxFAIL_MSG(wxT("unknown seek mode"));
 190             // still fall through
 191
 192         case wxFromStart:
 193             origin = SEEK_SET;
 194             break;
 195
 196         case wxFromCurrent:
 197             origin = SEEK_CUR;
 198             break;
 199
 200         case wxFromEnd:
 201             origin = SEEK_END;
 202             break;
 203     }
 204
 205 #ifndef HAVE_FSEEKO
 206     if ((long)ofs != ofs)
 207     {
 208         wxLogError(_("Seek error on file '%s' (large files not supported by stdio)"), m_name.c_str());
 209
 210         return false;
 211     }
 212
 213     if ( wxFseek(m_fp, (long)ofs, origin) != 0 )
 214 #else
 215     if ( wxFseek(m_fp, ofs, origin) != 0 )
 216 #endif
 217     {
 218         wxLogSysError(_("Seek error on file '%s'"), m_name.c_str());
 219
 220         return false;
 221     }
 222
 223     return true;
 224 }
 225
 226 wxFileOffset wxFFile::Tell() const
 227 {
 228     wxCHECK_MSG( IsOpened(), wxInvalidOffset,
 229                  _T("wxFFile::Tell(): file is closed!") );
 230
 231     wxFileOffset rc = wxFtell(m_fp);
 232     if ( rc == wxInvalidOffset )
 233     {
 234         wxLogSysError(_("Can't find current position in file '%s'"),
 235                       m_name.c_str());
 236     }
 237
 238     return rc;
 239 }
 240
 241 wxFileOffset wxFFile::Length() const
 242 {
 243     wxCHECK_MSG( IsOpened(), wxInvalidOffset,
 244                  _T("wxFFile::Length(): file is closed!") );
 245
 246     wxFFile& self = *(wxFFile *)this;   // const_cast
 247
 248     wxFileOffset posOld = Tell();
 249     if ( posOld != wxInvalidOffset )
 250     {
 251         if ( self.SeekEnd() )
 252         {
 253             wxFileOffset len = Tell();
 254
 255             (void)self.Seek(posOld);
 256
 257             return len;
 258         }
 259     }
 260
 261     return wxInvalidOffset;
 262 }
 263
 264 #endif // wxUSE_FFILE