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( _T("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(), _T("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, _T("should be at start of file") );
 128
 129         char *dst = buf.data();
 130         for ( ;; )
 131         {
 132             ssize_t nRead = m_file.Read(dst, BLOCK_SIZE);
 133
 134             if ( nRead == wxInvalidOffset )
 135             {
 136                 // read error (error message already given in wxFile::Read)
 137                 return false;
 138             }
 139
 140             if ( nRead == 0 )
 141             {
 142                 // this file can't be empty because we checked for this above
 143                 break;
 144             }
 145
 146             dst += nRead;
 147         }
 148
 149         wxASSERT_MSG( dst - buf.data() == (wxFileOffset)bufSize,
 150                       _T("logic error") );
 151     }
 152     else // file is not seekable
 153     {
 154         char block[BLOCK_SIZE];
 155         for ( ;; )
 156         {
 157             ssize_t nRead = m_file.Read(block, WXSIZEOF(block));
 158
 159             if ( nRead == wxInvalidOffset )
 160             {
 161                 // read error (error message already given in wxFile::Read)
 162                 return false;
 163             }
 164
 165             if ( nRead == 0 )
 166             {
 167                 // if no bytes have been read, presumably this is a
 168                 // valid-but-empty file
 169                 if ( bufSize == 0 )
 170                     return true;
 171
 172                 // otherwise we've finished reading the file
 173                 break;
 174             }
 175
 176             // extend the buffer for new data
 177             if ( !buf.extend(bufSize + nRead) )
 178                 return false;
 179
 180             // and append it to the buffer
 181             memcpy(buf.data() + bufSize, block, nRead);
 182             bufSize += nRead;
 183         }
 184     }
 185
 186     const wxString str(buf, conv, bufSize);
 187
 188     // there's no risk of this happening in ANSI build
 189 #if wxUSE_UNICODE
 190     if ( bufSize > 4 && str.empty() )
 191     {
 192         wxLogError(_("Failed to convert file \"%s\" to Unicode."), GetName());
 193         return false;
 194     }
 195 #endif // wxUSE_UNICODE
 196
 197     // we don't need this memory any more
 198     buf.reset();
 199
 200
 201     // now break the buffer in lines
 202
 203     // last processed character, we need to know if it was a CR or not
 204     wxChar chLast = '\0';
 205
 206     // the beginning of the current line, changes inside the loop
 207     wxString::const_iterator lineStart = str.begin();
 208     const wxString::const_iterator end = str.end();
 209     for ( wxString::const_iterator p = lineStart; p != end; p++ )
 210     {
 211         const wxChar ch = *p;
 212         switch ( ch )
 213         {
 214             case '\n':
 215                 // could be a DOS or Unix EOL
 216                 if ( chLast == '\r' )
 217                 {
 218                     if ( p - 1 >= lineStart )
 219                     {
 220                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Dos);
 221                     }
 222                     else
 223                     {
 224                         // there were two line endings, so add an empty line:
 225                         AddLine(wxEmptyString, wxTextFileType_Dos);
 226                     }
 227                 }
 228                 else // bare '\n', Unix style
 229                 {
 230                     AddLine(wxString(lineStart, p), wxTextFileType_Unix);
 231                 }
 232
 233                 lineStart = p + 1;
 234                 break;
 235
 236             case '\r':
 237                 if ( chLast == '\r' )
 238                 {
 239                     // Mac empty line
 240                     AddLine(wxEmptyString, wxTextFileType_Mac);
 241                     lineStart = p + 1;
 242                 }
 243                 //else: we don't know what this is yet -- could be a Mac EOL or
 244                 //      start of DOS EOL so wait for next char
 245                 break;
 246
 247             default:
 248                 if ( chLast == '\r' )
 249                 {
 250                     // Mac line termination
 251                     if ( p - 1 >= lineStart )
 252                     {
 253                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Mac);
 254                     }
 255                     else
 256                     {
 257                         // there were two line endings, so add an empty line:
 258                         AddLine(wxEmptyString, wxTextFileType_Mac);
 259                     }
 260                     lineStart = p;
 261                 }
 262         }
 263
 264         chLast = ch;
 265     }
 266
 267     // anything in the last line?
 268     if ( lineStart != end )
 269     {
 270         // add unterminated last line
 271         AddLine(wxString(lineStart, end), wxTextFileType_None);
 272     }
 273
 274     return true;
 275 }
 276
 277
 278 bool wxTextFile::OnWrite(wxTextFileType typeNew, const wxMBConv& conv)
 279 {
 280     wxFileName fn = m_strBufferName;
 281
 282     // We do NOT want wxPATH_NORM_CASE here, or the case will not
 283     // be preserved.
 284     if ( !fn.IsAbsolute() )
 285         fn.Normalize(wxPATH_NORM_ENV_VARS | wxPATH_NORM_DOTS | wxPATH_NORM_TILDE |
 286                      wxPATH_NORM_ABSOLUTE | wxPATH_NORM_LONG);
 287
 288     wxTempFile fileTmp(fn.GetFullPath());
 289
 290     if ( !fileTmp.IsOpened() ) {
 291         wxLogError(_("can't write buffer '%s' to disk."), m_strBufferName.c_str());
 292         return false;
 293     }
 294
 295     size_t nCount = GetLineCount();
 296     for ( size_t n = 0; n < nCount; n++ ) {
 297         fileTmp.Write(GetLine(n) +
 298                       GetEOL(typeNew == wxTextFileType_None ? GetLineType(n)
 299                                                             : typeNew),
 300                       conv);
 301     }
 302
 303     // replace the old file with this one
 304     return fileTmp.Commit();
 305 }
 306
 307 #endif // wxUSE_TEXTFILE