rom/oop/obtainattrbase.c

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: OOP function OOP_ObtainAttrBase
   6     Lang: english
   7 */
   8
   9 #include "intern.h"
  10 #include "hash.h"
  11 /*****************************************************************************
  12
  13     NAME */
  14 #include <string.h>
  15
  16 #include <proto/exec.h>
  17 #include <exec/memory.h>
  18 #include <aros/libcall.h>
  19
  20 #include <aros/debug.h>
  21
  22         AROS_LH1(OOP_AttrBase, OOP_ObtainAttrBase,
  23
  24 /*  SYNOPSIS */
  25         AROS_LHA(STRPTR         , interfaceID, A0),
  26
  27 /*  LOCATION */
  28         struct Library *, OOPBase, 6, OOP)
  29
  30 /*  FUNCTION
  31         Maps a globally unique string interface ID into
  32         a numeric AttrBase ID that is unique on
  33         pr. machine basis. The AttrBase can be combiner
  34         with attribute offsets to generate attribute IDs.
  35
  36
  37
  38     INPUTS
  39         interfaceID     - globally unique interface identifier.
  40                           for which to obtain an attrbase.
  41
  42     RESULT
  43         Numeric AttrBase that is unique for this machine.
  44         A return value of 0 means that the call failed.
  45
  46     NOTES
  47         Obtained attrbases should be released with ReleasAttrBase().
  48
  49     EXAMPLE
  50         #define aTimer_CurrentTime    (__AB_Timer + aoTime_CurrentTime)
  51
  52         ..
  53         __AB_Timer = OOP_ObtainAttrBase(IID_Timer);
  54
  55         SetAttrs(timer, aTimer_CurrentTime, "10:37:00");
  56
  57
  58     BUGS
  59
  60     SEE ALSO
  61
  62     INTERNALS
  63
  64     HISTORY
  65
  66 ******************************************************************************/
  67 {
  68     AROS_LIBFUNC_INIT
  69     AROS_LIBBASE_EXT_DECL(struct Library*,OOPBase)
  70
  71     /* Look up ID */
  72     struct iid_bucket *idb;
  73     struct HashTable *iidtable = GetOBase(OOPBase)->ob_IIDTable;
  74     ULONG base = -1UL;
  75
  76     EnterFunc(bug("OOP_ObtainAttrBase(interfaceID=%s)\n", interfaceID));
  77
  78     ObtainSemaphore(&GetOBase(OOPBase)->ob_IIDTableLock);
  79
  80
  81     /* Has ID allready been mapped to a numeric ID ? */
  82     idb = (struct iid_bucket *)iidtable->Lookup(iidtable, (IPTR)interfaceID, GetOBase(OOPBase));
  83     if (idb)
  84     {
  85
  86         /* If so, it has been stored in the hashtable, and we have
  87         ** to return the same numeric ID now.
  88         */
  89         if (idb->attrbase == -1UL)
  90         {
  91             idb->attrbase = GetOBase(OOPBase)->ob_CurrentAttrBase ++;
  92         }
  93
  94         base = idb->attrbase;
  95         base <<= NUM_METHOD_BITS;
  96
  97         D(bug("Bucket found: id=%ld\n", base));
  98     }
  99     else
 100     {
 101
 102         D(bug("No existing bucket\n"));
 103
 104
 105         /* If not, then map it and create a new bucket in the
 106         ** hashtable to store it
 107         */
 108         idb = AllocMem(sizeof (struct iid_bucket), MEMF_ANY|MEMF_CLEAR);
 109         if (idb)
 110         {
 111             idb->interface_id = AllocVec(strlen(interfaceID) + 1, MEMF_ANY);
 112             if (idb->interface_id)
 113             {
 114                 D(bug("Allocated bucket\n"));
 115                 strcpy(idb->interface_id, interfaceID);
 116
 117                 /* Get next free ID, and increase the free ID count to mark it as used */
 118                 base = idb->attrbase = ++ GetOBase(OOPBase)->ob_CurrentAttrBase;
 119
 120                 base <<= NUM_METHOD_BITS;
 121
 122                 /* Methodbase not inited yet */
 123                 idb->methodbase = -1UL;
 124
 125                 /* Insert bucket into hash table */
 126                 InsertBucket(iidtable, (struct Bucket *)idb, GetOBase(OOPBase));
 127             }
 128             else
 129             {
 130                 FreeMem(idb, sizeof (struct iid_bucket));
 131
 132 /* Throw exception here ? */
 133                 base = 0UL;
 134             }
 135         }
 136     }
 137
 138     if (base)
 139     {
 140         /* Increase refcount of bucket */
 141         idb->refcount ++;
 142     }
 143
 144     ReleaseSemaphore(&GetOBase(OOPBase)->ob_IIDTableLock);
 145
 146     ReturnInt ("OOP_ObtainAttrBase", AttrBase, base);
 147
 148     AROS_LIBFUNC_EXIT
 149
 150 } /* OOP_ObtainAttrBase  */
 151