rom/dos/setvbuf.c

   1 /*
   2     Copyright © 1995-2008, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5 #include <proto/exec.h>
   6
   7 #include "dos_intern.h"
   8
   9 #include <aros/debug.h>
  10
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <dos/stdio.h>
  16 #include <proto/dos.h>
  17
  18         AROS_LH4(LONG, SetVBuf,
  19
  20 /*        SetVBuf -- set buffering modes and size */
  21
  22 /*  SYNOPSIS */
  23         AROS_LHA(BPTR  , file, D1),
  24         AROS_LHA(STRPTR, buff, D2),
  25         AROS_LHA(LONG  , type, D3),
  26         AROS_LHA(LONG  , size, D4),
  27
  28 /*  LOCATION */
  29         struct DosLibrary *, DOSBase, 61, Dos)
  30
  31 /*  FUNCTION
  32         Changes the buffering modes and buffer size for a filehandle.
  33         With buff == NULL, the current buffer will be deallocated and a
  34         new one of (approximately) size will be allocated.  If buffer is
  35         non-NULL, it will be used for buffering and must be at least
  36         max(size,208) bytes long, and MUST be longword aligned.  If size
  37         is -1, then only the buffering mode will be changed.
  38
  39     INPUTS
  40         file - Filehandle
  41         buff - buffer pointer for buffered I/O or NULL.
  42         type - buffering mode (see <dos/stdio.h>)
  43         size - size of buffer for buffered I/O (sizes less than 208 bytes
  44                will be rounded up to 208), or -1.
  45
  46     RESULT
  47         0 if operation succeeded.
  48
  49 *****************************************************************************/
  50 {
  51     AROS_LIBFUNC_INIT
  52
  53     struct FileHandle *fh = (struct FileHandle *)BADDR(file);
  54
  55     ASSERT_VALID_PTR( fh );
  56     ASSERT_VALID_PTR_OR_NULL(buff);
  57
  58     switch (type)
  59     {
  60         case BUF_LINE:
  61             fh->fh_Flags = (fh->fh_Flags & ~FHF_NOBUF) | FHF_LINEBUF;
  62             break;
  63
  64         case BUF_FULL:
  65             fh->fh_Flags = fh->fh_Flags & ~(FHF_NOBUF | FHF_LINEBUF);
  66             break;
  67
  68         case BUF_NONE:
  69             fh->fh_Flags = (fh->fh_Flags | FHF_NOBUF) & ~FHF_LINEBUF;
  70             break;
  71
  72         default:
  73             return EOF;
  74     }
  75
  76     if (size != -1)
  77     {
  78         if (size < 208)
  79         {
  80             size = 208;
  81         }
  82
  83         vbuf_free(fh);
  84
  85         if (NULL != buff)
  86         {
  87             fh->fh_Size = size;
  88             if(fh->fh_Flags & FHF_WRITE)
  89             {
  90                 fh->fh_Pos = fh->fh_Buf = buff;
  91                 fh->fh_End = fh->fh_Buf + fh->fh_Size;
  92             }
  93             else
  94             {
  95                 fh->fh_Pos = fh->fh_Buf = fh->fh_End = buff;
  96             }
  97         }
  98         else
  99         {
 100             if (NULL == vbuf_alloc(fh, size, DOSBase))
 101             {
 102                 return(EOF);
 103             }
 104         }
 105     }
 106
 107     return 0;
 108
 109     AROS_LIBFUNC_EXIT
 110 } /* SetVBuf */
 111
 112
 113 void
 114 vbuf_free(FileHandlePtr fh)
 115 {
 116     /* free buffer allocated by system */
 117     if (fh->fh_Flags & FHF_BUF)
 118     {
 119         FreeMem(fh->fh_Buf, fh->fh_Size);
 120
 121         fh->fh_Buf = fh->fh_Pos = fh->fh_End = NULL;
 122         fh->fh_Size = 0;
 123     }
 124
 125     fh->fh_Flags &= ~FHF_BUF;
 126 }
 127
 128
 129 APTR
 130 vbuf_alloc(FileHandlePtr fh, ULONG size, struct DosLibrary *DOSBase)
 131 {
 132         STRPTR
 133     buf = AllocMem(size, MEMF_ANY);
 134
 135     if (NULL != buf)
 136     {
 137         fh->fh_Size = size;
 138         fh->fh_Flags |= FHF_BUF;
 139
 140         if(fh->fh_Flags & FHF_WRITE)
 141         {
 142             fh->fh_Pos = fh->fh_Buf = buf;
 143             fh->fh_End = fh->fh_Buf + fh->fh_Size;
 144         }
 145         else
 146         {
 147             fh->fh_Pos = fh->fh_Buf = fh->fh_End = buf;
 148         }
 149     }
 150
 151     return(fh->fh_Buf);
 152 }