libio/iofopncook.c

   1 /*
   2 Copyright (C) 1993, 1995 Free Software Foundation
   3
   4 This file is part of the GNU IO Library.  This library is free
   5 software; you can redistribute it and/or modify it under the
   6 terms of the GNU General Public License as published by the
   7 Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This library is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this library; see the file COPYING.  If not, write to the Free
  17 Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  18
  19 As a special exception, if you link this library with files
  20 compiled with a GNU compiler to produce an executable, this does not cause
  21 the resulting executable to be covered by the GNU General Public License.
  22 This exception does not however invalidate any other reasons why
  23 the executable file might be covered by the GNU General Public License. */
  24
  25 #include <libioP.h>
  26 #include <stdlib.h>
  27
  28 struct _IO_cookie_file {
  29   struct _IO_FILE file;
  30   const void *vtable;
  31   void *cookie;
  32   _IO_cookie_io_functions_t io_functions;
  33 };
  34
  35
  36 static _IO_ssize_t
  37 _IO_cookie_read (fp, buf, size)
  38      register _IO_FILE* fp;
  39      void* buf;
  40      _IO_ssize_t size;
  41 {
  42   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  43
  44   if (cfile->io_functions.read == NULL)
  45     return -1;
  46
  47   return cfile->io_functions.read (cfile->cookie, buf, size);
  48 }
  49
  50 static _IO_ssize_t
  51 _IO_cookie_write (fp, buf, size)
  52      register _IO_FILE* fp;
  53      const void* buf;
  54      _IO_ssize_t size;
  55 {
  56   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  57
  58   if (cfile->io_functions.write == NULL)
  59     return -1;
  60
  61   return cfile->io_functions.write (cfile->cookie, buf, size);
  62 }
  63
  64 static _IO_fpos_t
  65 _IO_cookie_seek (fp, offset, dir)
  66      _IO_FILE *fp;
  67      _IO_off_t offset;
  68      int dir;
  69 {
  70   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  71   _IO_fpos_t pos;
  72
  73   if (cfile->io_functions.seek == NULL)
  74     return _IO_pos_BAD;
  75
  76   pos = _IO_pos_0;
  77   _IO_pos_adjust (pos, offset);
  78
  79   if (cfile->io_functions.seek (cfile->cookie, pos, dir))
  80     return _IO_pos_BAD;
  81
  82   return pos;
  83 }
  84
  85 static int
  86 _IO_cookie_close (fp)
  87      _IO_FILE* fp;
  88 {
  89   struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
  90
  91   if (cfile->io_functions.close == NULL)
  92     return 0;
  93
  94   return cfile->io_functions.close (cfile->cookie);
  95 }
  96
  97
  98 static struct _IO_jump_t _IO_cookie_jumps = {
  99   JUMP_INIT_DUMMY,
 100   JUMP_INIT(finish, _IO_file_finish),
 101   JUMP_INIT(overflow, _IO_file_overflow),
 102   JUMP_INIT(underflow, _IO_file_underflow),
 103   JUMP_INIT(uflow, _IO_default_uflow),
 104   JUMP_INIT(pbackfail, _IO_default_pbackfail),
 105   JUMP_INIT(xsputn, _IO_file_xsputn),
 106   JUMP_INIT(xsgetn, _IO_default_xsgetn),
 107   JUMP_INIT(seekoff, _IO_file_seekoff),
 108   JUMP_INIT(seekpos, _IO_default_seekpos),
 109   JUMP_INIT(setbuf, _IO_file_setbuf),
 110   JUMP_INIT(sync, _IO_file_sync),
 111   JUMP_INIT(doallocate, _IO_file_doallocate),
 112   JUMP_INIT(read, _IO_cookie_read),
 113   JUMP_INIT(write, _IO_cookie_write),
 114   JUMP_INIT(seek, _IO_cookie_seek),
 115   JUMP_INIT(close, _IO_cookie_close),
 116   JUMP_INIT(stat, _IO_default_stat)
 117 };
 118
 119
 120 _IO_FILE *
 121 fopencookie (cookie, mode, io_functions)
 122      void *cookie;
 123      const char *mode;
 124      _IO_cookie_io_functions_t io_functions;
 125 {
 126   int read_write;
 127   struct _IO_cookie_file *cfile;
 128
 129   switch (*mode++)
 130     {
 131     case 'r':
 132       read_write = _IO_NO_WRITES;
 133       break;
 134     case 'w':
 135       read_write = _IO_NO_READS;
 136       break;
 137     case 'a':
 138       read_write = _IO_NO_READS|_IO_IS_APPENDING;
 139       break;
 140     default:
 141       return NULL;
 142   }
 143   if (mode[0] == '+' || (mode[0] == 'b' && mode[1] == '+'))
 144     read_write &= _IO_IS_APPENDING;
 145
 146   cfile  = (struct _IO_cookie_file *) malloc (sizeof (struct _IO_cookie_file));
 147   if (cfile == NULL)
 148     return NULL;
 149
 150   _IO_init (&cfile->file, 0);
 151   _IO_JUMPS (&cfile->file) = &_IO_cookie_jumps;
 152   cfile->cookie = cookie;
 153   cfile->io_functions = io_functions;
 154
 155   _IO_file_init(&cfile->file);
 156
 157   cfile->file._IO_file_flags =
 158     _IO_mask_flags (&cfile->file, read_write,
 159                     _IO_NO_READS+_IO_NO_WRITES+_IO_IS_APPENDING);
 160
 161   return &cfile->file;
 162 }
 163