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wxWidgets/src/common/ffile.cpp

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/////////////////////////////////////////////////////////////////////////////
// Name: src/common/ffile.cpp
// Purpose: wxFFile encapsulates "FILE *" IO stream
// Author: Vadim Zeitlin
// Modified by:
// Created: 14.07.99
// Copyright: (c) 1998 Vadim Zeitlin <zeitlin@dptmaths.ens-cachan.fr>
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
// ============================================================================
// declarations
// ============================================================================
// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#if wxUSE_FFILE
#ifndef WX_PRECOMP
#include "wx/intl.h"
#include "wx/log.h"
#include "wx/crt.h"
#endif
#include "wx/filename.h"
#include "wx/ffile.h"
// ============================================================================
// implementation of wxFFile
// ============================================================================
// ----------------------------------------------------------------------------
// opening the file
// ----------------------------------------------------------------------------
wxFFile::wxFFile(const wxString& filename, const wxString& mode)
{
m_fp = NULL;
(void)Open(filename, mode);
}
bool wxFFile::Open(const wxString& filename, const wxString& mode)
{
wxASSERT_MSG( !m_fp, wxT("should close or detach the old file first") );
FILE* const fp = wxFopen(filename, mode);
if ( !fp )
{
wxLogSysError(_("can't open file '%s'"), filename);
return false;
}
Attach(fp, filename);
return true;
}
bool wxFFile::Close()
{
if ( IsOpened() )
{
if ( fclose(m_fp) != 0 )
{
wxLogSysError(_("can't close file '%s'"), m_name.c_str());
return false;
}
m_fp = NULL;
}
return true;
}
// ----------------------------------------------------------------------------
// read/write
// ----------------------------------------------------------------------------
bool wxFFile::ReadAll(wxString *str, const wxMBConv& conv)
{
wxCHECK_MSG( str, false, wxT("invalid parameter") );
wxCHECK_MSG( IsOpened(), false, wxT("can't read from closed file") );
wxCHECK_MSG( Length() >= 0, false, wxT("invalid length") );
size_t length = wx_truncate_cast(size_t, Length());
wxCHECK_MSG( (wxFileOffset)length == Length(), false, wxT("huge file not supported") );
clearerr(m_fp);
wxCharBuffer buf(length);
// note that real length may be less than file length for text files with DOS EOLs
// ('\r's get dropped by CRT when reading which means that we have
// realLen = fileLen - numOfLinesInTheFile)
length = fread(buf.data(), 1, length, m_fp);
if ( Error() )
{
wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
return false;
}
// shrink the buffer to possibly shorter data as explained above:
buf.shrink(length);
wxString strTmp(buf, conv);
str->swap(strTmp);
return true;
}
size_t wxFFile::Read(void *pBuf, size_t nCount)
{
if ( !nCount )
return 0;
wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
wxCHECK_MSG( IsOpened(), 0, wxT("can't read from closed file") );
size_t nRead = fread(pBuf, 1, nCount, m_fp);
if ( (nRead < nCount) && Error() )
{
wxLogSysError(_("Read error on file '%s'"), m_name.c_str());
}
return nRead;
}
size_t wxFFile::Write(const void *pBuf, size_t nCount)
{
if ( !nCount )
return 0;
wxCHECK_MSG( pBuf, 0, wxT("invalid parameter") );
wxCHECK_MSG( IsOpened(), 0, wxT("can't write to closed file") );
size_t nWritten = fwrite(pBuf, 1, nCount, m_fp);
if ( nWritten < nCount )
{
wxLogSysError(_("Write error on file '%s'"), m_name.c_str());
}
return nWritten;
}
bool wxFFile::Write(const wxString& s, const wxMBConv& conv)
{
// Writing nothing always succeeds -- and simplifies the check for
// conversion failure below.
if ( s.empty() )
return true;
const wxWX2MBbuf buf = s.mb_str(conv);
#if wxUSE_UNICODE
const size_t size = buf.length();
if ( !size )
{
// This means that the conversion failed as the original string wasn't
// empty (we explicitly checked for this above) and in this case we
// must fail too to indicate that we can't save the data.
return false;
}
#else
const size_t size = s.length();
#endif
return Write(buf, size) == size;
}
bool wxFFile::Flush()
{
if ( IsOpened() )
{
if ( fflush(m_fp) != 0 )
{
wxLogSysError(_("failed to flush the file '%s'"), m_name.c_str());
return false;
}
}
return true;
}
// ----------------------------------------------------------------------------
// seeking
// ----------------------------------------------------------------------------
bool wxFFile::Seek(wxFileOffset ofs, wxSeekMode mode)
{
wxCHECK_MSG( IsOpened(), false, wxT("can't seek on closed file") );
int origin;
switch ( mode )
{
default:
wxFAIL_MSG(wxT("unknown seek mode"));
wxFALLTHROUGH;
case wxFromStart:
origin = SEEK_SET;
break;
case wxFromCurrent:
origin = SEEK_CUR;
break;
case wxFromEnd:
origin = SEEK_END;
break;
}
#ifndef wxHAS_LARGE_FFILES
if ((long)ofs != ofs)
{
wxLogError(_("Seek error on file '%s' (large files not supported by stdio)"), m_name.c_str());
return false;
}
if ( wxFseek(m_fp, (long)ofs, origin) != 0 )
#else
if ( wxFseek(m_fp, ofs, origin) != 0 )
#endif
{
wxLogSysError(_("Seek error on file '%s'"), m_name.c_str());
return false;
}
return true;
}
wxFileOffset wxFFile::Tell() const
{
wxCHECK_MSG( IsOpened(), wxInvalidOffset,
wxT("wxFFile::Tell(): file is closed!") );
wxFileOffset rc = wxFtell(m_fp);
if ( rc == wxInvalidOffset )
{
wxLogSysError(_("Can't find current position in file '%s'"),
m_name.c_str());
}
return rc;
}
wxFileOffset wxFFile::Length() const
{
wxCHECK_MSG( IsOpened(), wxInvalidOffset,
wxT("wxFFile::Length(): file is closed!") );
wxFileOffset posOld = Tell();
if ( posOld != wxInvalidOffset )
{
wxFFile& self = *const_cast<wxFFile*>(this);
if ( self.SeekEnd() )
{
wxFileOffset len = Tell();
(void)self.Seek(posOld);
return len;
}
}
return wxInvalidOffset;
}
bool wxFFile::Eof() const
{
wxCHECK_MSG( IsOpened(), false,
wxT("wxFFile::Eof(): file is closed!") );
return feof(m_fp) != 0;
}
bool wxFFile::Error() const
{
wxCHECK_MSG( IsOpened(), false,
wxT("wxFFile::Error(): file is closed!") );
return ferror(m_fp) != 0;
}
// ============================================================================
// implementation of wxTempFFile
// ============================================================================
// ----------------------------------------------------------------------------
// construction
// ----------------------------------------------------------------------------
wxTempFFile::wxTempFFile(const wxString& strName)
{
Open(strName);
}
bool wxTempFFile::Open(const wxString& strName)
{
// we must have an absolute filename because otherwise CreateTempFileName()
// would create the temp file in $TMP (i.e. the system standard location
// for the temp files) which might be on another volume/drive/mount and
// wxRename()ing it later to m_strName from Commit() would then fail
//
// with the absolute filename, the temp file is created in the same
// directory as this one which ensures that wxRename() may work later
wxFileName fn(strName);
if ( !fn.IsAbsolute() )
{
fn.Normalize(wxPATH_NORM_ABSOLUTE);
}
m_strName = fn.GetFullPath();
m_strTemp = wxFileName::CreateTempFileName(m_strName, &m_file);
if ( m_strTemp.empty() )
{
// CreateTempFileName() failed
return false;
}
#ifdef __UNIX__
// the temp file should have the same permissions as the original one
mode_t mode;
wxStructStat st;
if ( stat( (const char*) m_strName.fn_str(), &st) == 0 )
{
mode = st.st_mode;
}
else
{
// file probably didn't exist, just give it the default mode _using_
// user's umask (new files creation should respect umask)
mode_t mask = umask(0777);
mode = 0666 & ~mask;
umask(mask);
}
if ( chmod( (const char*) m_strTemp.fn_str(), mode) == -1 )
{
wxLogSysError(_("Failed to set temporary file permissions"));
}
#endif // Unix
return true;
}
// ----------------------------------------------------------------------------
// destruction
// ----------------------------------------------------------------------------
wxTempFFile::~wxTempFFile()
{
if ( IsOpened() )
Discard();
}
bool wxTempFFile::Commit()
{
m_file.Close();
if ( wxFile::Exists(m_strName) && wxRemove(m_strName) != 0 ) {
wxLogSysError(_("can't remove file '%s'"), m_strName.c_str());
return false;
}
if ( !wxRenameFile(m_strTemp, m_strName) ) {
wxLogSysError(_("can't commit changes to file '%s'"), m_strName.c_str());
return false;
}
return true;
}
void wxTempFFile::Discard()
{
m_file.Close();
if ( wxRemove(m_strTemp) != 0 )
{
wxLogSysError(_("can't remove temporary file '%s'"), m_strTemp.c_str());
}
}
#endif // wxUSE_FFILE