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 but there is no good way to avoid it in Unicode build because if we
  96     // 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            bufPos = 0;
 103     char block[1024];
 104     wxCharBuffer buf;
 105
 106     // first determine if the file is seekable or not and so whether we can
 107     // determine its length in advance
 108     wxFileOffset fileLength;
 109     {
 110         wxLogNull logNull;
 111         fileLength = m_file.Length();
 112     }
 113
 114     // some non-seekable files under /proc under Linux pretend that they're
 115     // seekable but always return 0; others do return an error
 116     const bool seekable = fileLength != wxInvalidOffset && fileLength != 0;
 117     if ( seekable )
 118     {
 119         // we know the required length, so set the buffer size in advance
 120         bufSize = fileLength;
 121         if ( !buf.extend(bufSize - 1 /* it adds 1 internally */) )
 122             return false;
 123
 124         // if the file is seekable, also check that we're at its beginning
 125         wxASSERT_MSG( m_file.Tell() == 0, _T("should be at start of file") );
 126     }
 127
 128     for ( ;; )
 129     {
 130         ssize_t nRead = m_file.Read(block, WXSIZEOF(block));
 131
 132         if ( nRead == wxInvalidOffset )
 133         {
 134             // read error (error message already given in wxFile::Read)
 135             return false;
 136         }
 137
 138         if ( nRead == 0 )
 139         {
 140             // if no bytes have been read, presumably this is a valid-but-empty file
 141             if ( bufPos == 0 )
 142                 return true;
 143
 144             // otherwise we've finished reading the file
 145             break;
 146         }
 147
 148         if ( seekable )
 149         {
 150             // this shouldn't happen but don't overwrite the buffer if it does
 151             wxCHECK_MSG( bufPos + nRead <= bufSize, false,
 152                          _T("read more than file length?") );
 153         }
 154         else // !seekable
 155         {
 156             // for non-seekable files we have to allocate more memory on the go
 157             if ( !buf.extend(bufPos + nRead - 1 /* it adds 1 internally */) )
 158                 return false;
 159         }
 160
 161         // append to the buffer
 162         memcpy(buf.data() + bufPos, block, nRead);
 163         bufPos += nRead;
 164     }
 165
 166     if ( !seekable )
 167     {
 168         bufSize = bufPos;
 169     }
 170
 171     const wxString str(buf, conv, bufPos);
 172
 173     // there's no risk of this happening in ANSI build
 174 #if wxUSE_UNICODE
 175     if ( bufSize > 4 && str.empty() )
 176     {
 177         wxLogError(_("Failed to convert file \"%s\" to Unicode."), GetName());
 178         return false;
 179     }
 180 #endif // wxUSE_UNICODE
 181
 182     free(buf.release()); // we don't need this memory any more
 183
 184
 185     // now break the buffer in lines
 186
 187     // last processed character, we need to know if it was a CR or not
 188     wxChar chLast = '\0';
 189
 190     // the beginning of the current line, changes inside the loop
 191     wxString::const_iterator lineStart = str.begin();
 192     const wxString::const_iterator end = str.end();
 193     for ( wxString::const_iterator p = lineStart; p != end; p++ )
 194     {
 195         const wxChar ch = *p;
 196         switch ( ch )
 197         {
 198             case '\n':
 199                 // could be a DOS or Unix EOL
 200                 if ( chLast == '\r' )
 201                 {
 202                     if ( p - 1 >= lineStart )
 203                     {
 204                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Dos);
 205                     }
 206                     else
 207                     {
 208                         // there were two line endings, so add an empty line:
 209                         AddLine(wxEmptyString, wxTextFileType_Dos);
 210                     }
 211                 }
 212                 else // bare '\n', Unix style
 213                 {
 214                     AddLine(wxString(lineStart, p), wxTextFileType_Unix);
 215                 }
 216
 217                 lineStart = p + 1;
 218                 break;
 219
 220             case '\r':
 221                 if ( chLast == '\r' )
 222                 {
 223                     // Mac empty line
 224                     AddLine(wxEmptyString, wxTextFileType_Mac);
 225                     lineStart = p + 1;
 226                 }
 227                 //else: we don't know what this is yet -- could be a Mac EOL or
 228                 //      start of DOS EOL so wait for next char
 229                 break;
 230
 231             default:
 232                 if ( chLast == '\r' )
 233                 {
 234                     // Mac line termination
 235                     if ( p - 1 >= lineStart )
 236                     {
 237                         AddLine(wxString(lineStart, p - 1), wxTextFileType_Mac);
 238                     }
 239                     else
 240                     {
 241                         // there were two line endings, so add an empty line:
 242                         AddLine(wxEmptyString, wxTextFileType_Mac);
 243                     }
 244                     lineStart = p;
 245                 }
 246         }
 247
 248         chLast = ch;
 249     }
 250
 251     // anything in the last line?
 252     if ( lineStart != end )
 253     {
 254         // add unterminated last line
 255         AddLine(wxString(lineStart, end), wxTextFileType_None);
 256     }
 257
 258     return true;
 259 }
 260
 261
 262 bool wxTextFile::OnWrite(wxTextFileType typeNew, const wxMBConv& conv)
 263 {
 264     wxFileName fn = m_strBufferName;
 265
 266     // We do NOT want wxPATH_NORM_CASE here, or the case will not
 267     // be preserved.
 268     if ( !fn.IsAbsolute() )
 269         fn.Normalize(wxPATH_NORM_ENV_VARS | wxPATH_NORM_DOTS | wxPATH_NORM_TILDE |
 270                      wxPATH_NORM_ABSOLUTE | wxPATH_NORM_LONG);
 271
 272     wxTempFile fileTmp(fn.GetFullPath());
 273
 274     if ( !fileTmp.IsOpened() ) {
 275         wxLogError(_("can't write buffer '%s' to disk."), m_strBufferName.c_str());
 276         return false;
 277     }
 278
 279     size_t nCount = GetLineCount();
 280     for ( size_t n = 0; n < nCount; n++ ) {
 281         fileTmp.Write(GetLine(n) +
 282                       GetEOL(typeNew == wxTextFileType_None ? GetLineType(n)
 283                                                             : typeNew),
 284                       conv);
 285     }
 286
 287     // replace the old file with this one
 288     return fileTmp.Commit();
 289 }
 290
 291 #endif // wxUSE_TEXTFILE