michael@0: /*
michael@0:  * Copyright (c) 1999
michael@0:  * Silicon Graphics Computer Systems, Inc.
michael@0:  *
michael@0:  * Copyright (c) 1999
michael@0:  * Boris Fomitchev
michael@0:  *
michael@0:  * This material is provided "as is", with absolutely no warranty expressed
michael@0:  * or implied. Any use is at your own risk.
michael@0:  *
michael@0:  * Permission to use or copy this software for any purpose is hereby granted
michael@0:  * without fee, provided the above notices are retained on all copies.
michael@0:  * Permission to modify the code and to distribute modified code is granted,
michael@0:  * provided the above notices are retained, and a notice that the code was
michael@0:  * modified is included with the above copyright notice.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: #include <fstream>
michael@0: 
michael@0: #if !defined (_STLP_WCE)
michael@0: #  ifdef __BORLANDC__
michael@0: #    include <cfcntl.h>           // For _O_RDONLY, etc
michael@0: #  else
michael@0: #    include <io.h>               // For _get_osfhandle
michael@0: #    include <fcntl.h>            // For _O_RDONLY, etc
michael@0: #  endif
michael@0: #  include <sys/stat.h>         // For _fstat
michael@0: #endif
michael@0: 
michael@0: #define _TEXTBUF_SIZE 0x1000
michael@0: 
michael@0: const _STLP_fd INVALID_STLP_FD = INVALID_HANDLE_VALUE;
michael@0: 
michael@0: #if !defined (INVALID_SET_FILE_POINTER)
michael@0: #  define INVALID_SET_FILE_POINTER 0xffffffff
michael@0: #endif
michael@0: 
michael@0: #ifndef O_ACCMODE
michael@0: #  define O_ACCMODE (O_RDONLY|O_WRONLY|O_RDWR)
michael@0: #endif
michael@0: 
michael@0: _STLP_BEGIN_NAMESPACE
michael@0: 
michael@0: #if !defined(__MSL__) && !defined(_STLP_WCE)
michael@0: static ios_base::openmode flag_to_openmode(int mode) {
michael@0:   ios_base::openmode ret = ios_base::__default_mode;
michael@0: 
michael@0:   switch (mode & O_ACCMODE) {
michael@0:   case O_RDONLY:
michael@0:     ret = ios_base::in; break;
michael@0:   case O_WRONLY:
michael@0:     ret = ios_base::out; break;
michael@0:   case O_RDWR:
michael@0:     ret = ios_base::in | ios_base::out; break;
michael@0:   }
michael@0: 
michael@0:   if (mode & O_APPEND)
michael@0:     ret |= ios_base::app;
michael@0: 
michael@0:   if (mode & O_BINARY)
michael@0:     ret |= ios_base::binary;
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: #endif
michael@0: 
michael@0: _STLP_MOVE_TO_PRIV_NAMESPACE
michael@0: 
michael@0: // Helper functions for _Filebuf_base.
michael@0: 
michael@0: static bool __is_regular_file(_STLP_fd fd) {
michael@0:   BY_HANDLE_FILE_INFORMATION info;
michael@0: 
michael@0:   // Return true if the file handle isn't a directory.
michael@0:   return GetFileInformationByHandle(fd, &info) && 
michael@0:          ((info.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY) == 0);
michael@0: }
michael@0: 
michael@0: // Number of characters in the file.
michael@0: static streamoff __file_size(_STLP_fd fd) {
michael@0:   streamoff ret = 0;
michael@0: 
michael@0:  LARGE_INTEGER li;
michael@0:  li.LowPart = GetFileSize(fd, (unsigned long*) &li.HighPart);
michael@0:  if (li.LowPart != INVALID_FILE_SIZE || GetLastError() == NO_ERROR)
michael@0:    ret = li.QuadPart;
michael@0: 
michael@0:   return ret;
michael@0: }
michael@0: 
michael@0: _STLP_MOVE_TO_STD_NAMESPACE
michael@0: 
michael@0: // Visual C++ and Intel use this, but not Metrowerks
michael@0: // Also MinGW, msvcrt.dll (but not crtdll.dll) dependent version
michael@0: #if (defined (_STLP_MSVC_LIB) && !defined (_STLP_WCE)) || \
michael@0:     (defined (__MINGW32__) && defined (__MSVCRT__))
michael@0: 
michael@0: // fcntl(fileno, F_GETFL) for Microsoft library
michael@0: // 'semi-documented' defines:
michael@0: #  define IOINFO_L2E          5
michael@0: #  define IOINFO_ARRAY_ELTS   (1 << IOINFO_L2E)
michael@0: #  define _pioinfo(i) ( __pioinfo[(i) >> IOINFO_L2E] + \
michael@0:               ((i) & (IOINFO_ARRAY_ELTS - 1)) )
michael@0: #  define FAPPEND         0x20    // O_APPEND flag
michael@0: #  define FTEXT           0x80    // O_TEXT flag
michael@0: // end of 'semi-documented' defines
michael@0: 
michael@0: // 'semi-documented' internal structure
michael@0: extern "C" {
michael@0:   struct ioinfo {
michael@0:     long osfhnd;    // the real os HANDLE
michael@0:     char osfile;    // file handle flags
michael@0:     char pipech;    // pipe buffer
michael@0: #  if defined (_MT)
michael@0:     // multi-threaded locking
michael@0:     int lockinitflag;
michael@0:     CRITICAL_SECTION lock;
michael@0: #  endif
michael@0:   };
michael@0: #  if defined (__MINGW32__)
michael@0:  __MINGW_IMPORT ioinfo * __pioinfo[];
michael@0: #  else
michael@0:   extern _CRTIMP ioinfo * __pioinfo[];
michael@0: #  endif
michael@0: } // extern "C"
michael@0: // end of 'semi-documented' declarations
michael@0: 
michael@0: static ios_base::openmode _get_osfflags(int fd, HANDLE oshandle) {
michael@0:   char dosflags = 0;
michael@0:   if (fd >= 0)
michael@0:     dosflags = _pioinfo(fd)->osfile;
michael@0:   //else
michael@0:     //the file will be considered as open in binary mode with no append attribute
michael@0:   // end of 'semi-documented' stuff
michael@0: 
michael@0:   int mode = 0;
michael@0:   if (dosflags & FAPPEND)
michael@0:     mode |= O_APPEND;
michael@0: 
michael@0:   if (dosflags & FTEXT)
michael@0:     mode |= O_TEXT;
michael@0:   else
michael@0:     mode |= O_BINARY;
michael@0: 
michael@0:   // For Read/Write access we have to guess
michael@0:   DWORD dummy, dummy2;
michael@0:   BOOL writeOk = WriteFile(oshandle, &dummy2, 0, &dummy, 0);
michael@0:   BOOL readOk = ReadFile(oshandle, &dummy2, 0, &dummy, NULL);
michael@0:   if (writeOk && readOk)
michael@0:     mode |= O_RDWR;
michael@0:   else if (readOk)
michael@0:     mode |= O_RDONLY;
michael@0:   else
michael@0:     mode |= O_WRONLY;
michael@0: 
michael@0:   return flag_to_openmode(mode);
michael@0: }
michael@0: 
michael@0: #elif defined (__DMC__)
michael@0: 
michael@0: #  define FHND_APPEND 0x04
michael@0: #  define FHND_DEVICE 0x08
michael@0: #  define FHND_TEXT   0x10
michael@0: 
michael@0: extern "C" unsigned char __fhnd_info[_NFILE];
michael@0: 
michael@0: static ios_base::openmode _get_osfflags(int fd, HANDLE oshandle) {
michael@0:   int mode = 0;
michael@0: 
michael@0:   if (__fhnd_info[fd] & FHND_APPEND)
michael@0:     mode |= O_APPEND;
michael@0: 
michael@0:   if (__fhnd_info[fd] & FHND_TEXT == 0)
michael@0:     mode |= O_BINARY;
michael@0: 
michael@0:   for (FILE *fp = &_iob[0]; fp < &_iob[_NFILE]; fp++) {
michael@0:     if ((fileno(fp) == fd) && (fp->_flag & (_IOREAD | _IOWRT | _IORW))) {
michael@0:       const int osflags = fp->_flag;
michael@0: 
michael@0:       if ((osflags & _IOREAD) && !(osflags & _IOWRT) && !(osflags & _IORW))
michael@0:         mode |= O_RDONLY;
michael@0:       else if ((osflags & _IOWRT) && !(osflags & _IOREAD) && !(osflags & _IORW))
michael@0:         mode |= O_WRONLY;
michael@0:       else
michael@0:         mode |= O_RDWR;
michael@0:       break;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   return flag_to_openmode(mode);
michael@0: }
michael@0: #endif
michael@0: 
michael@0: size_t _Filebuf_base::_M_page_size = 4096;
michael@0: 
michael@0: _Filebuf_base::_Filebuf_base()
michael@0:   : _M_file_id(INVALID_STLP_FD),
michael@0:     _M_openmode(0),
michael@0:     _M_is_open(false),
michael@0:     _M_should_close(false),
michael@0:     _M_view_id(0)
michael@0: {}
michael@0: 
michael@0: void _Filebuf_base::_S_initialize() {
michael@0:   SYSTEM_INFO SystemInfo;
michael@0:   GetSystemInfo(&SystemInfo);
michael@0:   _M_page_size = SystemInfo.dwPageSize;
michael@0:   // might be .dwAllocationGranularity
michael@0: }
michael@0: 
michael@0: // Return the size of the file.  This is a wrapper for stat.
michael@0: // Returns zero if the size cannot be determined or is ill-defined.
michael@0: streamoff _Filebuf_base::_M_file_size() {
michael@0:   return _STLP_PRIV __file_size(_M_file_id);
michael@0: }
michael@0: 
michael@0: bool _Filebuf_base::_M_open(const char* name, ios_base::openmode openmode,
michael@0:                             long permission) {
michael@0:   _STLP_fd file_no;
michael@0: 
michael@0:   if (_M_is_open)
michael@0:     return false;
michael@0: 
michael@0:   DWORD dwDesiredAccess, dwCreationDisposition;
michael@0:   bool doTruncate = false;
michael@0: 
michael@0:   switch (openmode & (~ios_base::ate & ~ios_base::binary)) {
michael@0:   case ios_base::out:
michael@0:   case ios_base::out | ios_base::trunc:
michael@0:     dwDesiredAccess = GENERIC_WRITE;
michael@0:     dwCreationDisposition = OPEN_ALWAYS;
michael@0:     // boris : even though it is very non-intuitive, standard
michael@0:     // requires them both to behave same.
michael@0:     doTruncate = true;
michael@0:     break;
michael@0:   case ios_base::out | ios_base::app:
michael@0:     dwDesiredAccess = GENERIC_WRITE;
michael@0:     dwCreationDisposition = OPEN_ALWAYS;
michael@0:     break;
michael@0:   case ios_base::in:
michael@0:     dwDesiredAccess = GENERIC_READ;
michael@0:     dwCreationDisposition = OPEN_EXISTING;
michael@0:     permission = 0;             // Irrelevant unless we're writing.
michael@0:     break;
michael@0:   case ios_base::in | ios_base::out:
michael@0:     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
michael@0:     dwCreationDisposition = OPEN_EXISTING;
michael@0:     break;
michael@0:   case ios_base::in | ios_base::out | ios_base::trunc:
michael@0:     dwDesiredAccess = GENERIC_READ | GENERIC_WRITE;
michael@0:     dwCreationDisposition = OPEN_ALWAYS;
michael@0:     doTruncate = true;
michael@0:     break;
michael@0:   default:                      // The above are the only combinations of
michael@0:     return false;               // flags allowed by the C++ standard.
michael@0:   }
michael@0: 
michael@0:   DWORD dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
michael@0: 
michael@0: #if defined(_STLP_USE_WIDE_INTERFACE)
michael@0:     file_no = CreateFile (_STLP_PRIV __ASCIIToWide(name).c_str(),
michael@0: #else
michael@0:     file_no = CreateFileA(name,
michael@0: #endif
michael@0:                           dwDesiredAccess, dwShareMode, 0,
michael@0:                           dwCreationDisposition, permission, 0);
michael@0: 
michael@0:   if (file_no == INVALID_STLP_FD)
michael@0:     return false;
michael@0: 
michael@0:   if (
michael@0: #if !defined (_STLP_WCE)
michael@0:       GetFileType(file_no) == FILE_TYPE_DISK &&
michael@0: #endif
michael@0:       ((doTruncate && SetEndOfFile(file_no) == 0) ||
michael@0:        (((openmode & ios_base::ate) != 0) &&
michael@0:         (SetFilePointer(file_no, 0, NULL, FILE_END) == INVALID_SET_FILE_POINTER)))) {
michael@0:     CloseHandle(file_no);
michael@0:     return false;
michael@0:   }
michael@0: 
michael@0:   _M_is_open = true;
michael@0:   _M_file_id = file_no;
michael@0:   _M_should_close = _M_is_open;
michael@0:   _M_openmode = openmode;
michael@0: 
michael@0:   if (_M_is_open)
michael@0:     _M_regular_file = _STLP_PRIV __is_regular_file(_M_file_id);
michael@0: 
michael@0:   return (_M_is_open != 0);
michael@0: }
michael@0: 
michael@0: bool _Filebuf_base::_M_open(const char* name, ios_base::openmode openmode) {
michael@0:   // This doesn't really grant everyone in the world read/write
michael@0:   // access.  On Unix, file-creation system calls always clear
michael@0:   // bits that are set in the umask from the permissions flag.
michael@0:   return this->_M_open(name, openmode, FILE_ATTRIBUTE_NORMAL);
michael@0: }
michael@0: 
michael@0: bool _Filebuf_base::_M_open(_STLP_fd __id, ios_base::openmode init_mode) {
michael@0: #if (defined (_STLP_MSVC_LIB) && !defined (_STLP_WCE)) || \
michael@0:     (defined (__MINGW32__) && defined (__MSVCRT__)) || defined (__DMC__)
michael@0: 
michael@0:   if (_M_is_open || __id == INVALID_STLP_FD)
michael@0:     return false;
michael@0: 
michael@0:   if (init_mode != ios_base::__default_mode)
michael@0:     _M_openmode = init_mode;
michael@0:   else
michael@0:     _M_openmode = _get_osfflags(-1, __id);
michael@0: 
michael@0:   _M_is_open = true;
michael@0:   _M_file_id = __id;
michael@0:   _M_should_close = false;
michael@0:   _M_regular_file = _STLP_PRIV __is_regular_file(_M_file_id);
michael@0: 
michael@0:   return true;
michael@0: #else
michael@0:   (void)__id;
michael@0:   (void)init_mode;    // dwa 4/27/00 - suppress unused parameter warning
michael@0: 
michael@0:   // not available for the API
michael@0:   return false;
michael@0: 
michael@0: #endif
michael@0: }
michael@0: 
michael@0: // Associated the filebuf with a file descriptor pointing to an already-
michael@0: // open file.  Mode is set to be consistent with the way that the file
michael@0: // was opened.
michael@0: bool _Filebuf_base::_M_open(int file_no, ios_base::openmode init_mode) {
michael@0:   if (_M_is_open || file_no < 0)
michael@0:     return false;
michael@0: 
michael@0: #if (defined (_STLP_MSVC_LIB) && !defined (_STLP_WCE)) || \
michael@0:     (defined (__MINGW32__) && defined (__MSVCRT__)) || defined (__DMC__)
michael@0: 
michael@0:   HANDLE oshandle = (HANDLE)_get_osfhandle(file_no);
michael@0:   if (oshandle == INVALID_STLP_FD)
michael@0:     return false;
michael@0: 
michael@0:   if (init_mode != ios_base::__default_mode)
michael@0:     _M_openmode = init_mode;
michael@0:   else
michael@0:     _M_openmode = _get_osfflags(file_no, oshandle);
michael@0: 
michael@0:   _M_file_id = oshandle;
michael@0:   _M_is_open = true;
michael@0:   _M_should_close = false;
michael@0:   _M_regular_file = _STLP_PRIV __is_regular_file(_M_file_id);
michael@0:   return true;
michael@0: #else
michael@0:   _STLP_MARK_PARAMETER_AS_UNUSED(&init_mode)
michael@0:   // not available for the API
michael@0:   return false;
michael@0: #endif
michael@0: }
michael@0: 
michael@0: bool _Filebuf_base::_M_close() {
michael@0:   if (!_M_is_open)
michael@0:     return false;
michael@0: 
michael@0:   bool ok;
michael@0: 
michael@0:   if (!_M_should_close)
michael@0:     ok = true;
michael@0:   else {
michael@0:     if (_M_file_id != INVALID_STLP_FD) {
michael@0:       ok = (CloseHandle(_M_file_id) != 0);
michael@0:     }
michael@0:     else {
michael@0:       ok = false;
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   _M_is_open = _M_should_close = false;
michael@0:   _M_openmode = 0;
michael@0:   return ok;
michael@0: }
michael@0: 
michael@0: 
michael@0: #define _STLP_LF 10
michael@0: #define _STLP_CR 13
michael@0: #define _STLP_CTRLZ 26
michael@0: 
michael@0: // Read up to n characters into a buffer.  Return value is number of
michael@0: // characters read.
michael@0: ptrdiff_t _Filebuf_base::_M_read(char* buf, ptrdiff_t n) {
michael@0:   ptrdiff_t readen = 0;
michael@0:   //Here cast to size_t is safe as n cannot be negative.
michael@0:   size_t chunkSize = (min)(size_t(0xffffffff), __STATIC_CAST(size_t, n));
michael@0:   // The following, while validating that we are still able to extract chunkSize
michael@0:   // charaters to the buffer, avoids extraction of too small chunk of datas
michael@0:   // which would be counter performant.
michael@0:   while (__STATIC_CAST(size_t, (n - readen)) >= chunkSize) {
michael@0:     DWORD numberOfBytesRead;
michael@0:     ReadFile(_M_file_id, buf + readen, __STATIC_CAST(DWORD, chunkSize), &numberOfBytesRead, 0);
michael@0: 
michael@0:     if (numberOfBytesRead == 0)
michael@0:       break;
michael@0: 
michael@0:     if (!(_M_openmode & ios_base::binary)) {
michael@0:       // translate CR-LFs to LFs in the buffer
michael@0:       char *to = buf + readen;
michael@0:       char *from = to;
michael@0:       char *last = from + numberOfBytesRead - 1;
michael@0:       for (; from <= last && *from != _STLP_CTRLZ; ++from) {
michael@0:         if (*from != _STLP_CR)
michael@0:           *to++ = *from;
michael@0:         else { // found CR
michael@0:           if (from < last) { // not at buffer end
michael@0:             if (*(from + 1) != _STLP_LF)
michael@0:               *to++ = _STLP_CR;
michael@0:           }
michael@0:           else { // last char is CR, peek for LF
michael@0:             char peek = ' ';
michael@0:             DWORD NumberOfBytesPeeked;
michael@0:             ReadFile(_M_file_id, (LPVOID)&peek, 1, &NumberOfBytesPeeked, 0);
michael@0:             if (NumberOfBytesPeeked != 0) {
michael@0:               if (peek != _STLP_LF) { //not a <CR><LF> combination
michael@0:                 *to++ = _STLP_CR;
michael@0:                 if ((to < buf + n) && (peek != _STLP_CR))
michael@0:                   //We have enough place to store peek and it is no a special
michael@0:                   //_STLP_CR character, we can store it.
michael@0:                   *to++ = peek;
michael@0:                 else
michael@0:                   SetFilePointer(_M_file_id, (LONG)-1, 0, FILE_CURRENT);
michael@0:               }
michael@0:               else {
michael@0:                 // A <CR><LF> combination, we keep the <LF>:
michael@0:                 *to++ = _STLP_LF;
michael@0:               }
michael@0:             }
michael@0:             else {
michael@0:               /* This case is tedious, we could
michael@0:                *  - put peek back in the file but this would then generate an infinite loop
michael@0:                *  - report an error as we don't know if in a future call to ReadFile we won't then
michael@0:                *    get a <LF>. Doing so would make all files with a <CR> last an invalid file
michael@0:                *    for STLport, a hard solution for STLport clients.
michael@0:                *  - store the <CR> in the returned buffer, the chosen solution, even if in this
michael@0:                *    case we could miss a <CR><LF> combination.
michael@0:                */
michael@0:               *to++ = _STLP_CR;
michael@0:             }
michael@0:           }
michael@0:         } // found CR
michael@0:       } // for
michael@0:       readen = to - buf;
michael@0:       // seek back to TEXT end of file if hit CTRL-Z
michael@0:       if (from <= last) { // terminated due to CTRLZ
michael@0:         SetFilePointer(_M_file_id, -(LONG)((last + 1) - from), 0, FILE_CURRENT);
michael@0:         break;
michael@0:       }
michael@0:     }
michael@0:     else
michael@0:       readen += numberOfBytesRead;
michael@0:   }
michael@0:   return readen;
michael@0: }
michael@0: 
michael@0: // Write n characters from a buffer.  Return value: true if we managed
michael@0: // to write the entire buffer, false if we didn't.
michael@0: bool _Filebuf_base::_M_write(char* buf, ptrdiff_t n) {
michael@0:   for (;;) {
michael@0:     ptrdiff_t written;
michael@0: 
michael@0:     //In the following implementation we are going to cast most of the ptrdiff_t
michael@0:     //values in size_t to work with coherent unsigned values. Doing so make code
michael@0:     //more simple especially in the min function call.
michael@0: 
michael@0:     // In append mode, every write does an implicit seek to the end
michael@0:     // of the file.
michael@0:     if (_M_openmode & ios_base::app)
michael@0:       _M_seek(0, ios_base::end);
michael@0: 
michael@0:     if (_M_openmode & ios_base::binary) {
michael@0:       // binary mode
michael@0:       size_t bytes_to_write = (size_t)n;
michael@0:       DWORD NumberOfBytesWritten;
michael@0:       written = 0;
michael@0:       for (; bytes_to_write != 0;) {
michael@0:         WriteFile(_M_file_id, buf + written,
michael@0:                   __STATIC_CAST(DWORD, (min)(size_t(0xffffffff), bytes_to_write)),
michael@0:                   &NumberOfBytesWritten, 0);
michael@0:         if (NumberOfBytesWritten == 0)
michael@0:           return false;
michael@0:         bytes_to_write -= NumberOfBytesWritten;
michael@0:         written += NumberOfBytesWritten;
michael@0:       }
michael@0:     }
michael@0:     else {
michael@0:       char textbuf[_TEXTBUF_SIZE + 1]; // extra 1 in case LF at end
michael@0:       char * nextblock = buf, * ptrtextbuf = textbuf;
michael@0:       char * endtextbuf = textbuf + _TEXTBUF_SIZE;
michael@0:       char * endblock = buf + n;
michael@0:       ptrdiff_t nextblocksize = (min) (n, (ptrdiff_t)_TEXTBUF_SIZE);
michael@0:       char * nextlf;
michael@0: 
michael@0:       while ( (nextblocksize > 0) &&
michael@0:               (nextlf = (char *)memchr(nextblock, _STLP_LF, nextblocksize)) != 0) {
michael@0:         ptrdiff_t linelength = nextlf - nextblock;
michael@0:         memcpy(ptrtextbuf, nextblock, linelength);
michael@0:         ptrtextbuf += linelength;
michael@0:         nextblock += (linelength + 1);
michael@0:         * ptrtextbuf ++ = _STLP_CR;
michael@0:         * ptrtextbuf ++ = _STLP_LF;
michael@0:         nextblocksize = (min) (ptrdiff_t(endblock - nextblock),
michael@0:                                (max) (ptrdiff_t(0), ptrdiff_t(endtextbuf - ptrtextbuf)));
michael@0:       }
michael@0:       // write out what's left, > condition is here since for LF at the end ,
michael@0:       // endtextbuf may get < ptrtextbuf ...
michael@0:       if (nextblocksize > 0) {
michael@0:         memcpy(ptrtextbuf, nextblock, nextblocksize);
michael@0:         ptrtextbuf += nextblocksize;
michael@0:         nextblock += nextblocksize;
michael@0:       }
michael@0:       // now write out the translated buffer
michael@0:       char * writetextbuf = textbuf;
michael@0:       for (size_t NumberOfBytesToWrite = (size_t)(ptrtextbuf - textbuf);
michael@0:            NumberOfBytesToWrite;) {
michael@0:         DWORD NumberOfBytesWritten;
michael@0:         WriteFile((HANDLE)_M_file_id, writetextbuf,
michael@0:                   __STATIC_CAST(DWORD, (min)(size_t(0xffffffff), NumberOfBytesToWrite)),
michael@0:                   &NumberOfBytesWritten, 0);
michael@0:         if (!NumberOfBytesWritten) // write shortfall
michael@0:           return false;
michael@0:         writetextbuf += NumberOfBytesWritten;
michael@0:         NumberOfBytesToWrite -= NumberOfBytesWritten;
michael@0:       }
michael@0:       // count non-translated characters
michael@0:       written = (nextblock - buf);
michael@0:     }
michael@0: 
michael@0:     if (n == written)
michael@0:       return true;
michael@0:     else if (written > 0 && written < n) {
michael@0:       n -= written;
michael@0:       buf += written;
michael@0:     }
michael@0:     else
michael@0:       return false;
michael@0:   }
michael@0: }
michael@0: 
michael@0: // Wrapper for lseek or the like.
michael@0: streamoff _Filebuf_base::_M_seek(streamoff offset, ios_base::seekdir dir) {
michael@0:   streamoff result = -1;
michael@0:   int whence;
michael@0: 
michael@0:   switch(dir) {
michael@0:   case ios_base::beg:
michael@0:     if (offset < 0 /* || offset > _M_file_size() */ )
michael@0:       return streamoff(-1);
michael@0:     whence = FILE_BEGIN;
michael@0:     break;
michael@0:   case ios_base::cur:
michael@0:     whence = FILE_CURRENT;
michael@0:     break;
michael@0:   case ios_base::end:
michael@0:     if (/* offset > 0 || */  -offset > _M_file_size() )
michael@0:       return streamoff(-1);
michael@0:     whence = FILE_END;
michael@0:     break;
michael@0:   default:
michael@0:     return streamoff(-1);
michael@0:   }
michael@0: 
michael@0:   LARGE_INTEGER li;
michael@0:   li.QuadPart = offset;
michael@0:   li.LowPart = SetFilePointer(_M_file_id, li.LowPart, &li.HighPart, whence);
michael@0:   if (li.LowPart != INVALID_SET_FILE_POINTER || GetLastError() == NO_ERROR)
michael@0:     result = li.QuadPart;
michael@0: 
michael@0:   return result;
michael@0: }
michael@0: 
michael@0: 
michael@0: // Attempts to memory-map len bytes of the current file, starting
michael@0: // at position offset.  Precondition: offset is a multiple of the
michael@0: // page size.  Postcondition: return value is a null pointer if the
michael@0: // memory mapping failed.  Otherwise the return value is a pointer to
michael@0: // the memory-mapped file and the file position is set to offset.
michael@0: void* _Filebuf_base::_M_mmap(streamoff offset, streamoff len) {
michael@0:   void* base;
michael@0:   _M_view_id = CreateFileMapping(_M_file_id, (PSECURITY_ATTRIBUTES)0 ,
michael@0:                                  PAGE_READONLY, 0 /* len >> 32 */ ,
michael@0:                                  0 /* len & 0xFFFFFFFF */ , // low-order DWORD of size
michael@0:                                  0);
michael@0: 
michael@0:   if (_M_view_id) {
michael@0: #if 0
michael@0: /*
michael@0:     printf("view %x created from file %x, error = %d, size = %d, map_offset = %d map_len = %d\n",
michael@0:      _M_view_id, _M_file_id, GetLastError(),
michael@0:      (int)cur_filesize, ULL(offset) & 0xffffffff, len);
michael@0: */
michael@0: #endif
michael@0:     LARGE_INTEGER li;
michael@0:     li.QuadPart = offset;
michael@0:     base = MapViewOfFile(_M_view_id, FILE_MAP_READ, li.HighPart, li.LowPart,
michael@0: #if !defined (__DMC__)
michael@0:                          __STATIC_CAST(SIZE_T, len));
michael@0: #else
michael@0:                          __STATIC_CAST(DWORD, len));
michael@0: #endif
michael@0:     // check if mapping succeded and is usable
michael@0:     if (base == 0  || _M_seek(offset + len, ios_base::beg) < 0) {
michael@0:       this->_M_unmap(base, len);
michael@0:       base = 0;
michael@0:     }
michael@0:   } else
michael@0:     base = 0;
michael@0: 
michael@0:   return base;
michael@0: }
michael@0: 
michael@0: void _Filebuf_base::_M_unmap(void* base, streamoff len) {
michael@0:   // precondition : there is a valid mapping at the moment
michael@0:   if (base != NULL)
michael@0:     UnmapViewOfFile(base);
michael@0:   // destroy view handle as well
michael@0:   if (_M_view_id != NULL)
michael@0:     CloseHandle(_M_view_id);
michael@0:   _M_view_id = NULL;
michael@0:   (void)len; //unused variable
michael@0: }
michael@0: 
michael@0: _STLP_END_NAMESPACE