src/common/textfile.cpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/textfile.cpp
   3 // Purpose:     implementation of wxTextFile class
   4 // Author:      Vadim Zeitlin
   5 // Modified by:
   6 // Created:     03.04.98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // headers
  14 // ============================================================================
  15
  16 #include  "wx/wxprec.h"
  17
  18 #ifdef    __BORLANDC__
  19     #pragma hdrstop
  20 #endif  //__BORLANDC__
  21
  22 #if !wxUSE_FILE || !wxUSE_TEXTBUFFER
  23     #undef wxUSE_TEXTFILE
  24     #define wxUSE_TEXTFILE 0
  25 #endif // wxUSE_FILE
  26
  27 #if wxUSE_TEXTFILE
  28
  29 #ifndef WX_PRECOMP
  30     #include "wx/string.h"
  31     #include "wx/intl.h"
  32     #include "wx/file.h"
  33     #include "wx/log.h"
  34 #endif
  35
  36 #include "wx/textfile.h"
  37 #include "wx/filename.h"
  38 #include "wx/buffer.h"
  39
  40 // ============================================================================
  41 // wxTextFile class implementation
  42 // ============================================================================
  43
  44 wxTextFile::wxTextFile(const wxString& strFileName)
  45           : wxTextBuffer(strFileName)
  46 {
  47 }
  48
  49
  50 // ----------------------------------------------------------------------------
  51 // file operations
  52 // ----------------------------------------------------------------------------
  53
  54 bool wxTextFile::OnExists() const
  55 {
  56     return wxFile::Exists(m_strBufferName);
  57 }
  58
  59
  60 bool wxTextFile::OnOpen(const wxString &strBufferName, wxTextBufferOpenMode OpenMode)
  61 {
  62     wxFile::OpenMode FileOpenMode;
  63
  64     switch ( OpenMode )
  65     {
  66         default:
  67             wxFAIL_MSG( wxT("unknown open mode in wxTextFile::Open") );
  68             // fall through
  69
  70         case ReadAccess :
  71             FileOpenMode = wxFile::read;
  72             break;
  73
  74         case WriteAccess :
  75             FileOpenMode = wxFile::write;
  76             break;
  77     }
  78
  79     return m_file.Open(strBufferName.c_str(), FileOpenMode);
  80 }
  81
  82
  83 bool wxTextFile::OnClose()
  84 {
  85     return m_file.Close();
  86 }
  87
  88
  89 bool wxTextFile::OnRead(const wxMBConv& conv)
  90 {
  91     // file should be opened
  92     wxASSERT_MSG( m_file.IsOpened(), wxT("can't read closed file") );
  93
  94     // read the entire file in memory: this is not the most efficient thing to
  95     // do it but there is no good way to avoid it in Unicode build because if
  96     // we read the file block by block we can't convert each block to Unicode
  97     // separately (the last multibyte char in the block might be only partially
  98     // read and so the conversion would fail) and, as the file contents is kept
  99     // in memory by wxTextFile anyhow, it shouldn't be a big problem to read
 100     // the file entirely
 101     size_t bufSize = 0;
 102
 103     // number of bytes to (try to) read from disk at once
 104     static const size_t BLOCK_SIZE = 4096;
 105
 106     wxCharBuffer buf;
 107
 108     // first determine if the file is seekable or not and so whether we can
 109     // determine its length in advance
 110     wxFileOffset fileLength;
 111     {
 112         wxLogNull logNull;
 113         fileLength = m_file.Length();
 114     }
 115
 116     // some non-seekable files under /proc under Linux pretend that they're
 117     // seekable but always return 0; others do return an error
 118     const bool seekable = fileLength != wxInvalidOffset && fileLength != 0;
 119     if ( seekable )
 120     {
 121         // we know the required length, so set the buffer size in advance
 122         bufSize = fileLength;
 123         if ( !buf.extend(bufSize) )
 124             return false;
 125
 126         // if the file is seekable, also check that we're at its beginning
 127         wxASSERT_MSG( m_file.Tell() == 0, wxT("should be at start of file") );
 128
 129         char *dst = buf.data();
 130         for ( size_t nRemaining = bufSize; nRemaining > 0; )
 131         {
 132             size_t nToRead = BLOCK_SIZE;
 133
 134             // the file size could have changed, avoid overflowing the buffer
 135             // even if it did
 136             if ( nToRead > nRemaining )
 137                 nToRead = nRemaining;
 138
 139             ssize_t nRead = m_file.Read(dst, nToRead);
 140
 141             if ( nRead == wxInvalidOffset )
 142             {
 143                 // read error (error message already given in wxFile::Read)
 144                 return false;
 145             }
 146
 147             if ( nRead == 0 )
 148             {
 149                 // this file can't be empty because we checked for this above
 150                 // so this must be the end of file
 151                 break;
 152             }
 153
 154             dst += nRead;
 155             nRemaining -= nRead;
 156         }
 157
 158         wxASSERT_MSG( dst - buf.data() == (wxFileOffset)bufSize,
 159                       wxT("logic error") );
 160     }
 161     else // file is not seekable
 162     {
 163         char block[BLOCK_SIZE];
 164         for ( ;; )
 165         {
 166             ssize_t nRead = m_file.Read(block, WXSIZEOF(block));
 167
 168             if ( nRead == wxInvalidOffset )
 169             {
 170                 // read error (error message already given in wxFile::Read)
 171                 return false;
 172             }
 173
 174             if ( nRead == 0 )
 175             {
 176                 // if no bytes have been read, presumably this is a
 177                 // valid-but-empty file
 178                 if ( bufSize == 0 )
 179                     return true;
 180
 181                 // otherwise we've finished reading the file
 182                 break;
 183             }
 184
 185             // extend the buffer for new data
 186             if ( !buf.extend(bufSize + nRead) )
 187                 return false;
 188
 189             // and append it to the buffer
 190             memcpy(buf.data() + bufSize, block, nRead);
 191             bufSize += nRead;
 192         }
 193     }
 194
 195     const wxString str(buf, conv, bufSize);
 196
 197     // there's no risk of this happening in ANSI build
 198 #if wxUSE_UNICODE
 199     if ( bufSize > 4 && str.empty() )
 200     {
 201         wxLogError(_("Failed to convert file \"%s\" to Unicode."), GetName());
 202         return false;
 203     }
 204 #endif // wxUSE_UNICODE
 205
 206     // we don't need this memory any more
 207     buf.reset();
 208
 209
 210     // now break the buffer in lines
 211
 212     // last processed character, we need to know if it was a CR or not
 213     wxChar chLast = '\0';
 214
 215     // the beginning of the current line, changes inside the loop
 216     wxString::const_iterator lineStart = str.begin();
 217     const wxString::const_iterator end = str.end();
 218     for ( wxString::const_iterator p = lineStart; p != end; p++ )
 219     {
 220         const wxChar ch = *p;
 221         switch ( ch )
 222         {
 223             case '\n':
 224                 // could be a DOS or Unix EOL
 225                 if ( chLast == '\r' )
 226                 {
 227                     if ( p - 1 >= lineStart )
 228                     {
 229                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Dos);
 230                     }
 231                     else
 232                     {
 233                         // there were two line endings, so add an empty line:
 234                         AddLine(wxEmptyString, wxTextFileType_Dos);
 235                     }
 236                 }
 237                 else // bare '\n', Unix style
 238                 {
 239                     AddLine(wxString(lineStart, p), wxTextFileType_Unix);
 240                 }
 241
 242                 lineStart = p + 1;
 243                 break;
 244
 245             case '\r':
 246                 if ( chLast == '\r' )
 247                 {
 248                     // Mac empty line
 249                     AddLine(wxEmptyString, wxTextFileType_Mac);
 250                     lineStart = p + 1;
 251                 }
 252                 //else: we don't know what this is yet -- could be a Mac EOL or
 253                 //      start of DOS EOL so wait for next char
 254                 break;
 255
 256             default:
 257                 if ( chLast == '\r' )
 258                 {
 259                     // Mac line termination
 260                     if ( p - 1 >= lineStart )
 261                     {
 262                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Mac);
 263                     }
 264                     else
 265                     {
 266                         // there were two line endings, so add an empty line:
 267                         AddLine(wxEmptyString, wxTextFileType_Mac);
 268                     }
 269                     lineStart = p;
 270                 }
 271         }
 272
 273         chLast = ch;
 274     }
 275
 276     // anything in the last line?
 277     if ( lineStart != end )
 278     {
 279         // add unterminated last line
 280         AddLine(wxString(lineStart, end), wxTextFileType_None);
 281     }
 282
 283     return true;
 284 }
 285
 286
 287 bool wxTextFile::OnWrite(wxTextFileType typeNew, const wxMBConv& conv)
 288 {
 289     wxFileName fn = m_strBufferName;
 290
 291     // We do NOT want wxPATH_NORM_CASE here, or the case will not
 292     // be preserved.
 293     if ( !fn.IsAbsolute() )
 294         fn.Normalize(wxPATH_NORM_ENV_VARS | wxPATH_NORM_DOTS | wxPATH_NORM_TILDE |
 295                      wxPATH_NORM_ABSOLUTE | wxPATH_NORM_LONG);
 296
 297     wxTempFile fileTmp(fn.GetFullPath());
 298
 299     if ( !fileTmp.IsOpened() ) {
 300         wxLogError(_("can't write buffer '%s' to disk."), m_strBufferName.c_str());
 301         return false;
 302     }
 303
 304     size_t nCount = GetLineCount();
 305     for ( size_t n = 0; n < nCount; n++ ) {
 306         fileTmp.Write(GetLine(n) +
 307                       GetEOL(typeNew == wxTextFileType_None ? GetLineType(n)
 308                                                             : typeNew),
 309                       conv);
 310     }
 311
 312     // replace the old file with this one
 313     return fileTmp.Commit();
 314 }
 315
 316 #endif // wxUSE_TEXTFILE