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 #ifdef __WINDOWS__
  35 #include "wx/msw/mslu.h"
  36 #endif
  37
  38 #include "wx/ffile.h"
  39
  40 // ============================================================================
  41 // implementation
  42 // ============================================================================
  43
  44 // ----------------------------------------------------------------------------
  45 // seek and tell with large file support if available
  46 // ----------------------------------------------------------------------------
  47
  48 #ifdef HAVE_FSEEKO
  49 #   define wxFseek fseeko
  50 #   define wxFtell ftello
  51 #else
  52 #   define wxFseek fseek
  53 #   define wxFtell ftell
  54 #endif
  55
  56 // ----------------------------------------------------------------------------
  57 // opening the file
  58 // ----------------------------------------------------------------------------
  59
  60 wxFFile::wxFFile(const wxChar *filename, const wxChar *mode)
  61 {
  62     Detach();
  63
  64     (void)Open(filename, mode);
  65 }
  66
  67 bool wxFFile::Open(const wxChar *filename, const wxChar *mode)
  68 {
  69     wxASSERT_MSG( !m_fp, wxT("should close or detach the old file first") );
  70
  71     m_fp = wxFopen(filename, mode);
  72
  73     if ( !m_fp )
  74     {
  75         wxLogSysError(_("can't open file '%s'"), filename);
  76
  77         return false;
  78     }
  79
  80     m_name = filename;
  81
  82     return true;
  83 }
  84
  85 bool wxFFile::Close()
  86 {
  87     if ( IsOpened() )
  88     {
  89         if ( fclose(m_fp) != 0 )
  90         {
  91             wxLogSysError(_("can't close file '%s'"), m_name.c_str());
  92
  93             return false;
  94         }
  95
  96         Detach();
  97     }
  98
  99     return true;
 100 }
 101
 102 // ----------------------------------------------------------------------------
 103 // read/write
 104 // ----------------------------------------------------------------------------
 105
 106 bool wxFFile::ReadAll(wxString *str, wxMBConv& conv)
 107 {
 108     wxCHECK_MSG( str, false, wxT("invalid parameter") );
 109     wxCHECK_MSG( IsOpened(), false, wxT("can't read from closed file") );
 110     wxCHECK_MSG( Length() >= 0, false, wxT("invalid length") );
 111     size_t length = wx_truncate_cast(size_t, Length());
 112     wxCHECK_MSG( (wxFileOffset)length == Length(), false, wxT("huge file not supported") );
 113
 114     clearerr(m_fp);
 115
 116     wxCharBuffer buf(length + 1);
 117
 118     // note that real length may be less than file length for text files with DOS EOLs
 119     // ('\r's get dropped by CRT when reading which means that we have
 120     // realLen = fileLen - numOfLinesInTheFile)
 121     length = fread(buf.data(), sizeof(char), length, m_fp);
 122
 123     if ( Error() )
 124     {
 125         wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
 126
 127         return false;
 128     }
 129
 130     buf.data()[length] = 0;
 131     *str = wxString(buf, conv);
 132
 133     return true;
 134 }
 135
 136 size_t wxFFile::Read(void *pBuf, size_t nCount)
 137 {
 138     wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
 139     wxCHECK_MSG( IsOpened(), 0, wxT("can't read from closed file") );
 140
 141     size_t nRead = fread(pBuf, 1, nCount, m_fp);
 142     if ( (nRead < nCount) && Error() )
 143     {
 144         wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
 145     }
 146
 147     return nRead;
 148 }
 149
 150 size_t wxFFile::Write(const void *pBuf, size_t nCount)
 151 {
 152     wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
 153     wxCHECK_MSG( IsOpened(), 0, wxT("can't write to closed file") );
 154
 155     size_t nWritten = fwrite(pBuf, 1, nCount, m_fp);
 156     if ( nWritten < nCount )
 157     {
 158         wxLogSysError(_("Write error on file '%s'"), m_name.c_str());
 159     }
 160
 161     return nWritten;
 162 }
 163
 164 bool wxFFile::Flush()
 165 {
 166     if ( IsOpened() )
 167     {
 168         // fflush returns non-zero on error
 169         //
 170         if ( fflush(m_fp) )
 171         {
 172             wxLogSysError(_("failed to flush the file '%s'"), m_name.c_str());
 173
 174             return false;
 175         }
 176     }
 177
 178     return true;
 179 }
 180
 181 // ----------------------------------------------------------------------------
 182 // seeking
 183 // ----------------------------------------------------------------------------
 184
 185 bool wxFFile::Seek(wxFileOffset ofs, wxSeekMode mode)
 186 {
 187     wxCHECK_MSG( IsOpened(), false, wxT("can't seek on closed file") );
 188
 189     int origin;
 190     switch ( mode )
 191     {
 192         default:
 193             wxFAIL_MSG(wxT("unknown seek mode"));
 194             // still fall through
 195
 196         case wxFromStart:
 197             origin = SEEK_SET;
 198             break;
 199
 200         case wxFromCurrent:
 201             origin = SEEK_CUR;
 202             break;
 203
 204         case wxFromEnd:
 205             origin = SEEK_END;
 206             break;
 207     }
 208
 209 #ifndef HAVE_FSEEKO
 210     if ((long)ofs != ofs)
 211     {
 212         wxLogError(_("Seek error on file '%s' (large files not supported by stdio)"), m_name.c_str());
 213
 214         return false;
 215     }
 216
 217     if ( wxFseek(m_fp, (long)ofs, origin) != 0 )
 218 #else
 219     if ( wxFseek(m_fp, ofs, origin) != 0 )
 220 #endif
 221     {
 222         wxLogSysError(_("Seek error on file '%s'"), m_name.c_str());
 223
 224         return false;
 225     }
 226
 227     return true;
 228 }
 229
 230 wxFileOffset wxFFile::Tell() const
 231 {
 232     wxCHECK_MSG( IsOpened(), wxInvalidOffset,
 233                  _T("wxFFile::Tell(): file is closed!") );
 234
 235     wxFileOffset rc = wxFtell(m_fp);
 236     if ( rc == wxInvalidOffset )
 237     {
 238         wxLogSysError(_("Can't find current position in file '%s'"),
 239                       m_name.c_str());
 240     }
 241
 242     return rc;
 243 }
 244
 245 wxFileOffset wxFFile::Length() const
 246 {
 247     wxCHECK_MSG( IsOpened(), wxInvalidOffset,
 248                  _T("wxFFile::Length(): file is closed!") );
 249
 250     wxFFile& self = *(wxFFile *)this;   // const_cast
 251
 252     wxFileOffset posOld = Tell();
 253     if ( posOld != wxInvalidOffset )
 254     {
 255         if ( self.SeekEnd() )
 256         {
 257             wxFileOffset len = Tell();
 258
 259             (void)self.Seek(posOld);
 260
 261             return len;
 262         }
 263     }
 264
 265     return wxInvalidOffset;
 266 }
 267
 268 #endif // wxUSE_FFILE