rom/oop/parseattrs.c

   1 /*
   2     Copyright © 1995-2007, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: Parse a set of attributes in a single interface
   6     Lang: english
   7 */
   8 #include <exec/lists.h>
   9 #include <proto/exec.h>
  10 #include "intern.h"
  11
  12 /*****************************************************************************
  13
  14     NAME */
  15 #include <proto/oop.h>
  16
  17         AROS_LH5(LONG, OOP_ParseAttrs,
  18
  19 /*  SYNOPSIS */
  20         AROS_LHA(struct TagItem *, tags, A0),
  21         AROS_LHA(IPTR *, storage, A1),
  22         AROS_LHA(ULONG , numattrs, D0),
  23         AROS_LHA(OOP_AttrCheck *, attrcheck, A2),
  24         AROS_LHA(OOP_AttrBase  , attrbase, D1),
  25
  26 /*  LOCATION */
  27         struct Library *, OOPBase, 20, OOP)
  28
  29 /*  FUNCTION
  30         Parse a taglist of attributes and put the result in an array.
  31         It will only parse the attr from a single interface
  32         which is indicated by the 'attrbase' parameter.
  33
  34     INPUTS
  35         tags - tags to be parsed.
  36         storage - array where the tag values will be stored.
  37                   To get the value for a certain tag just use
  38                   ao#? attribute offset as an index into the array.
  39                   The array must be of size 'numattrs', ie. the number
  40                   of attributes in the interface.
  41
  42         numattrs - number of attributes in the interface.
  43         attrcheck - will is a flag that where flags will be set according
  44                     to the attributes' offset. Since this is only 32
  45                     bytes you can only parse interfaces
  46                     with <= 32 attributes with this function.
  47                     If you try with more, you will get a
  48                     ooperr_ParseAttrs_TooManyAttrs error.
  49                     The flags will be set like this if an attr is found:
  50
  51                     attrcheck |= 1L << attribute_offset
  52
  53         attrbase - attrbase for the interface whise attrs we should look for.
  54
  55
  56     RESULT
  57         0 for success, and an error otherwise.
  58         Possible values are:
  59                 ooperr_ParseAttrs_TooManyAttrs.
  60
  61     NOTES
  62
  63     EXAMPLE
  64
  65     BUGS
  66
  67     SEE ALSO
  68
  69     INTERNALS
  70
  71     HISTORY
  72         29-10-95    digulla automatically created from
  73                             intuition_lib.fd and clib/intuition_protos.h
  74
  75 *****************************************************************************/
  76 {
  77     AROS_LIBFUNC_INIT
  78
  79     LONG err = 0;
  80     BOOL done = FALSE;
  81
  82     if (numattrs > 32)
  83         return ooperr_ParseAttrs_TooManyAttrs;
  84
  85     /* Parse the taglist. Since we reimplement NextTagItem() instead
  86        of calling it this should be really fast. */
  87     while (!done) {
  88         register IPTR tag = tags->ti_Tag;
  89
  90         /* Instead of having a default: in switch we have an if test
  91            here because tag > TAG_SKIP is the most-often case.
  92
  93            With the way gcc generates code for switc() when
  94            there are low number of case: (no jumptable,
  95            just "binarysearch" jumping) this is much faster.
  96         */
  97         if (tag > TAG_SKIP) {
  98             /* Get the attribute offset */
  99             /* Look for same attrbase */
 100             if ((tag & (~METHOD_MASK)) == attrbase) {
 101                 register IPTR offset;
 102
 103                 offset = tag & METHOD_MASK;
 104                 if (offset >= numattrs)
 105                     continue;
 106
 107 // bug("---PARSERATTRS: OFFSET %d\n", offset);
 108                 storage[offset] = tags->ti_Data;
 109                 /* Mark it as found */
 110 // bug("--- ADDING %p TO ATTRCHECK\n", 1L << offset);
 111                 *attrcheck |= 1L << offset;
 112             }
 113         } else {
 114             switch (tag) {
 115                 case TAG_DONE:
 116                     return err;
 117
 118                 case TAG_IGNORE:
 119                     break;
 120
 121                 case TAG_MORE:
 122                     tags = (struct TagItem *)tags->ti_Data;
 123                     if (NULL == tags)
 124                         return err;
 125                     continue;
 126
 127                 case TAG_SKIP:
 128                     tags += tags->ti_Data + 1;
 129                     break;
 130             } /* swithc() */
 131         } /* if (tag <= TAG_SKIP) */
 132
 133         tags ++;
 134     }
 135
 136     return err;
 137
 138     AROS_LIBFUNC_EXIT
 139 } /* OOP_ParseAttrs */