granicus.if.org Git - postgresql/blob - src/port/open.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * open.c
   4  *         Win32 open() replacement
   5  *
   6  *
   7  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
   8  *
   9  * $PostgreSQL: pgsql/src/port/open.c,v 1.6 2004/11/17 08:30:11 neilc Exp $
  10  *
  11  *-------------------------------------------------------------------------
  12  */
  13
  14 #ifdef WIN32
  15
  16 #include <windows.h>
  17 #include <fcntl.h>
  18 #include <errno.h>
  19 #include <assert.h>
  20
  21 int win32_open(const char *fileName, int fileFlags, ...);
  22
  23 static int
  24 openFlagsToCreateFileFlags(int openFlags)
  25 {
  26         switch (openFlags & (O_CREAT | O_TRUNC | O_EXCL))
  27         {
  28                 case 0:
  29                 case O_EXCL:
  30                         return OPEN_EXISTING;
  31
  32                 case O_CREAT:
  33                         return OPEN_ALWAYS;
  34
  35                 case O_TRUNC:
  36                 case O_TRUNC | O_EXCL:
  37                         return TRUNCATE_EXISTING;
  38
  39                 case O_CREAT | O_TRUNC:
  40                         return CREATE_ALWAYS;
  41
  42                 case O_CREAT | O_EXCL:
  43                 case O_CREAT | O_TRUNC | O_EXCL:
  44                         return CREATE_NEW;
  45         }
  46
  47         /* will never get here */
  48         return 0;
  49 }
  50
  51 /*
  52  *       - file attribute setting, based on fileMode?
  53  *       - handle other flags? (eg FILE_FLAG_NO_BUFFERING/FILE_FLAG_WRITE_THROUGH)
  54  */
  55 int
  56 win32_open(const char *fileName, int fileFlags,...)
  57 {
  58         int                     fd;
  59         HANDLE          h;
  60         SECURITY_ATTRIBUTES sa;
  61
  62         /* Check that we can handle the request */
  63         assert((fileFlags & ((O_RDONLY | O_WRONLY | O_RDWR) | O_APPEND |
  64                                                  (O_RANDOM | O_SEQUENTIAL | O_TEMPORARY) |
  65                                                  _O_SHORT_LIVED |
  66           (O_CREAT | O_TRUNC | O_EXCL) | (O_TEXT | O_BINARY))) == fileFlags);
  67
  68         sa.nLength = sizeof(sa);
  69         sa.bInheritHandle = TRUE;
  70         sa.lpSecurityDescriptor = NULL;
  71
  72         if ((h = CreateFile(fileName,
  73         /* cannot use O_RDONLY, as it == 0 */
  74                                   (fileFlags & O_RDWR) ? (GENERIC_WRITE | GENERIC_READ) :
  75                                  ((fileFlags & O_WRONLY) ? GENERIC_WRITE : GENERIC_READ),
  76                                 /* These flags allow concurrent rename/unlink */
  77                                 (FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE),
  78                                                 &sa,
  79                                                 openFlagsToCreateFileFlags(fileFlags),
  80                                                 FILE_ATTRIBUTE_NORMAL |
  81                                  ((fileFlags & O_RANDOM) ? FILE_FLAG_RANDOM_ACCESS : 0) |
  82                    ((fileFlags & O_SEQUENTIAL) ? FILE_FLAG_SEQUENTIAL_SCAN : 0) |
  83                   ((fileFlags & _O_SHORT_LIVED) ? FILE_ATTRIBUTE_TEMPORARY : 0) |
  84                          ((fileFlags & O_TEMPORARY) ? FILE_FLAG_DELETE_ON_CLOSE : 0),
  85                                                 NULL)) == INVALID_HANDLE_VALUE)
  86         {
  87                 switch (GetLastError())
  88                 {
  89                                 /* EMFILE, ENFILE should not occur from CreateFile. */
  90                         case ERROR_PATH_NOT_FOUND:
  91                         case ERROR_FILE_NOT_FOUND:
  92                                 errno = ENOENT;
  93                                 break;
  94                         case ERROR_FILE_EXISTS:
  95                                 errno = EEXIST;
  96                                 break;
  97                         case ERROR_ACCESS_DENIED:
  98                                 errno = EACCES;
  99                                 break;
 100                         default:
 101                                 errno = EINVAL;
 102                 }
 103                 return -1;
 104         }
 105
 106         /* _open_osfhandle will, on error, set errno accordingly */
 107         if ((fd = _open_osfhandle((long) h, fileFlags & O_APPEND)) < 0 ||
 108                 (fileFlags & (O_TEXT | O_BINARY) && (_setmode(fd, fileFlags & (O_TEXT | O_BINARY)) < 0)))
 109                 CloseHandle(h);                 /* will not affect errno */
 110         return fd;
 111 }
 112
 113 #endif