Function file_pread_aux

src/hdaccess.c:1417–1531

@ @ requires \valid_read(disk); @ requires valid_disk(disk); @ requires \valid((char *)buf + (0 .. count - 1)); @*/

  @ requires \valid((char *)buf + (0 .. count - 1));
  @*/
static int file_pread_aux(const disk_t *disk, void *buf, const unsigned int count, const uint64_t offset)
{
  long int ret;
  const int fd=((const struct info_file_struct *)disk->data)->handle;
#if defined(__CYGWIN__)
  if(lseek(fd,offset,SEEK_SET) < 0)
  {
    log_error("file_pread(%d,%u,buffer,%lu(%u/%u/%u)) lseek err %s\n",
	fd, (unsigned)(count/disk->sector_size),
	(long unsigned int)(offset/disk->sector_size),
	offset2cylinder(disk,offset),
	offset2head(disk,offset),
	offset2sector(disk,offset),
	strerror(errno));
    return -1;
  }
  {
    /* November 28, 2004, CGR: cygwin read function is about 10 times slower
       because it reads 60k each time, so lets call ReadFile directly */
    DWORD dwByteRead;
    HANDLE handle=(HANDLE)get_osfhandle(fd);
    if(ReadFile(handle, buf,count,&dwByteRead,NULL)==0)
    {
      LPVOID lpMsgBuf;
      DWORD dw = GetLastError(); 
      FormatMessage(
	  FORMAT_MESSAGE_ALLOCATE_BUFFER | 
	  FORMAT_MESSAGE_FROM_SYSTEM,
	  NULL,
	  dw,
	  MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
	  (LPTSTR) &lpMsgBuf,
	  0, NULL );
      log_error("file_pread(%d,%u,buffer,%lu(%u/%u/%u)) ReadFile %s\n",
	fd, (unsigned)(count/disk->sector_size),
	(long unsigned int)(offset/disk->sector_size),
	offset2cylinder(disk, offset),
	offset2head(disk, offset),
	offset2sector(disk, offset),
	(char*)lpMsgBuf);
      LocalFree(lpMsgBuf);
      return -1;
    }
    return dwByteRead;
  }
#elif defined(__MINGW32__)
  if(_lseeki64(fd,offset,SEEK_SET) < 0)
  {
    log_error("file_pread(%d,%u,buffer,%lu(%u/%u/%u)) seek err %s\n",
	fd, (unsigned)(count/disk->sector_size),
	(long unsigned int)(offset/disk->sector_size),
	offset2cylinder(disk, offset),
	offset2head(disk, offset),
	offset2sector(disk, offset),
	strerror(errno));
    return -1;
  }
  ret=read(fd, buf, count);