Anybody can help?

Comments

• dwccgc

  October 2003

  [b][red]This message was edited by dwccgc at 2003-10-13 6:5:2[/red][/b][hr]
  [b][red]This message was edited by dwccgc at 2003-10-13 6:4:8[/red][/b][hr]
  CStdioFile in not designed for speed.
  If you look at the CStdioFileEx::ReadString(CString& rString) method you will see
  ..
  ..
  ..
  CString sTemp;
  
  This variable sTemp is created and destroyed, about 10,000 times for your program, everytime you read a line.
  
  Try using iostream.
  
  
  
  
  : [b][red]This message was edited by peachieboy at 2003-10-13 4:40:58[/red][/b][hr]
  : Hi guys, could anybody please share with me if they have ever enounter this situation.
  :
  : I have this software which opens a file in windows environment(MFC). i'm using the CStdio class. But the funny thing is it takes a very long time to read a file. I'm doing it line by line. For example to open a file consisting of arond 10,000 lines. (its a large file) it takes about 40 over secs.
  :
  : But the amazing thing is that under DOS c programming environment, it barely takes more than 2 secs....anybody can advise?
  :
  : ############################################################
  : ### this is the code from my program
  : #############################################################
  : if (fileEx.Open(m_sFilePath, CFile::modeRead | CFile::typeText))
  : {
  : FileTitle=fileEx.GetFileTitle();
  :
  :
  : while(fileEx.ReadString(sLine))
  : {
  : m_pgDemo.StepIt();
  :
  : sText += sLine + sNEWLINE;
  :
  : }
  : // Set lines in edit
  : m_editText.SetWindowText(sText);
  : m_pgDemo.SetPos(10000);
  : m_pgDemo.SetPos(0);
  :
  : fileEx.Close();
  : }
  :
  : ###########################################################
  : #this is the ReadString function
  : #############################################################
  :
  : BOOL CStdioFileEx::ReadString(CString& rString)
  : {
  : const int nMAX_LINE_CHARS = 4096;
  : BOOL bReadData;
  : LPTSTR lpsz;
  : int nLen = 0; //, nMultiByteBufferLength = 0, nChars = 0;
  : CString sTemp;
  : wchar_t* pszUnicodeString = NULL;
  : char * pszMultiByteString= NULL;
  :
  : // If at position 0, discard byte-order mark before reading
  : if (!m_pStream || (GetPosition() == 0 && m_bIsUnicodeText))
  : {
  : wchar_t cDummy;
  : // Read(&cDummy, sizeof(_TCHAR));
  : Read(&cDummy, sizeof(wchar_t));
  : }
  :
  : // If compiled for Unicode
  : #ifdef _UNICODE
  : // Do standard stuff -- both ANSI and Unicode cases seem to work OK
  : bReadData = CStdioFile::ReadString(rString);
  : #else
  :
  : if (!m_bIsUnicodeText)
  : {
  : // Do standard stuff -- read ANSI in ANSI
  : bReadData = CStdioFile::ReadString(rString);
  : }
  : else
  : {
  : pszUnicodeString = new wchar_t[nMAX_LINE_CHARS];
  : pszMultiByteString= new char[nMAX_LINE_CHARS];
  :
  : // Read as Unicode, convert to ANSI
  : fgetws(pszUnicodeString, nMAX_LINE_CHARS, m_pStream);
  : if (GetMultiByteStringFromUnicodeString(pszUnicodeString, pszMultiByteString, nMAX_LINE_CHARS))
  : {
  : rString = (CString)pszMultiByteString;
  : }
  :
  : if (pszUnicodeString)
  : {
  : delete pszUnicodeString;
  : }
  :
  : if (pszMultiByteString)
  : {
  : delete pszMultiByteString;
  : }
  : }
  : #endif
  :
  : // Then remove end-of-line character if in Unicode text mode
  : if (bReadData)
  : {
  : // Copied from FileTxt.cpp but adapted to Unicode and then adapted for end-of-line being just '
  '.
  : nLen = rString.GetLength();
  : if (nLen > 1 && rString.Mid(nLen-2) == sNEWLINE)
  : {
  : rString.GetBufferSetLength(nLen-2);
  : }
  : else
  : {
  : lpsz = rString.GetBuffer(0);
  : if (nLen != 0 && (lpsz[nLen-1] == _T('
  ') || lpsz[nLen-1] == _T('
  ')))
  : {
  : rString.GetBufferSetLength(nLen-1);
  : }
  : }
  : }
  :
  : return bReadData;
  : }
  :
  :
  :