workbench/libs/nonvolatile/nvdisk/readnvddata.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc:
   6     Lang: English
   7 */
   8
   9 /*****************************************************************************
  10
  11     NAME */
  12
  13 #include "nvdisk_intern.h"
  14 #include <dos/dos.h>
  15 #include <dos/dosextens.h>
  16 #include <proto/dos.h>
  17 #include <proto/exec.h>
  18 #include <exec/memory.h>
  19
  20
  21 AROS_LH2(APTR, ReadNVDData,
  22
  23 /*  SYNOPSIS */
  24
  25         AROS_LHA(STRPTR, appName,  A0),
  26         AROS_LHA(STRPTR, itemName, A1),
  27
  28 /*  LOCATION */
  29
  30         struct Library *, nvdBase, 5, NVDisk)
  31
  32 /*  FUNCTION
  33
  34     Read the nv data corresponding to appname, itemname.
  35
  36     INPUTS
  37
  38     appname   --  the name of the application owning the data
  39     itemname  --  the name of the data to retrieve
  40
  41     RESULT
  42
  43     A pointer to the data read. If something went wrong NULL is returned.
  44
  45     NOTES
  46
  47     EXAMPLE
  48
  49     BUGS
  50
  51     SEE ALSO
  52
  53     INTERNALS
  54
  55     HISTORY
  56
  57     November 2000,  SDuvan  --  implemented
  58
  59 ******************************************************************************/
  60
  61 {
  62     AROS_LIBFUNC_INIT
  63
  64     APTR  mem = NULL;
  65     BPTR  lock, lock2;
  66     BPTR  oldCDir;
  67
  68     /* Allocate a FileInfoBlock to be able to determine the size of the
  69        file containing the data. */
  70     struct FileInfoBlock *fib = AllocDosObject(DOS_FIB, NULL);
  71
  72     if(fib != NULL)
  73     {
  74         oldCDir = CurrentDir(GPB(nvdBase)->nvd_location);
  75         lock = Lock(appName, SHARED_LOCK);
  76
  77         if(lock)
  78         {
  79             CurrentDir(lock);
  80
  81             lock2 = Lock(itemName, SHARED_LOCK);
  82
  83             if(lock2 != BNULL)
  84             {
  85                 // We have now found the file -- check how big it is
  86                 Examine(lock2, fib);
  87
  88                 mem = AllocVec(fib->fib_Size, MEMF_ANY);
  89
  90                 if(mem != NULL)
  91                 {
  92                     if(Read(lock2, mem, fib->fib_Size) != fib->fib_Size)
  93                     {
  94                         FreeVec(mem);
  95                         mem = NULL;
  96                     }
  97
  98                 } /* if(mem) */
  99
 100                 UnLock(lock2);
 101
 102             } /* if(lock2) */
 103
 104             CurrentDir(oldCDir);
 105             UnLock(lock);
 106
 107         } /* if(lock) */
 108
 109         CurrentDir(oldCDir);
 110         FreeDosObject(DOS_FIB, fib);
 111
 112     } /* if(fib) */
 113
 114     return mem;
 115
 116     AROS_LIBFUNC_EXIT
 117 } /* ReadData */