rom/oop/metaclass.c

   1 /*
   2     Copyright © 1995-2011, The AROS Development Team. All rights reserved.
   3     $Id$
   4
   5     Desc: OOP metaclass
   6     Lang: english
   7 */
   8
   9 #include <proto/exec.h>
  10 #include <proto/utility.h>
  11 #include <exec/alerts.h>
  12 #include <exec/memory.h>
  13
  14 #include <proto/oop.h>
  15 #include <oop/oop.h>
  16
  17 #include "intern.h"
  18 #include "hash.h"
  19 #include "private.h"
  20
  21 #undef SDEBUG
  22 #undef DEBUG
  23 #define SDEBUG 0
  24 #define DEBUG 0
  25 /* #define DUMP_BUCKET */
  26
  27 #include <aros/debug.h>
  28
  29 #define IFI(cl) ((struct ifmeta_inst *)cl)
  30
  31 /* Allocates and initializes the interface hashtable, and the methodtables */
  32 static BOOL ifmeta_allocdisptabs(OOP_Class *cl, OOP_Object *o, struct P_meta_allocdisptabs *msg);
  33 static VOID ifmeta_freedisptabs(OOP_Class *cl, OOP_Object *o, OOP_Msg msg);
  34
  35 static IPTR Meta_DoMethod(OOP_Object *o, OOP_Msg msg);
  36 static IPTR Meta_CoerceMethod(OOP_Class *cl, OOP_Object *o, OOP_Msg msg);
  37 static IPTR Meta_DoSuperMethod(OOP_Class *cl, OOP_Object *o, OOP_Msg msg);
  38
  39 /* Hooks */
  40 VOID freebucket(struct Bucket *b, struct IntOOPBase *OOPBase);
  41 struct Bucket *copybucket(struct Bucket *old_b, APTR data, struct IntOOPBase *OOPBase);
  42
  43 /* Internal */
  44 static struct IFBucket *createbucket(CONST_STRPTR interface_id, ULONG local_id ,ULONG num_methods);
  45 static BOOL expandbucket(struct IFBucket *b, ULONG num_methods);
  46
  47 static ULONG calc_ht_entries(struct ifmeta_inst *cl ,OOP_Class *super,
  48                              const struct OOP_InterfaceDescr *ifDescr ,struct IntOOPBase *OOPBase);
  49
  50 /*
  51    The metaclass is used to create class. That means,
  52    classes are instances of the meta class.
  53    The meta class is itself both a class (you can
  54    create instances of it), and an object (you can invoke
  55    methods on it.
  56 */
  57
  58
  59 #ifdef DUMP_BUCKET
  60
  61 static void dump_bucket(struct IFBucket *b)
  62 {
  63     ULONG i;
  64
  65     bug("[META] Bucket 0x%p (%s) with %u methods:\n", b, b->GlobalInterfaceID, b->NumMethods);
  66
  67     for (i = 0; i < b->NumMethods; i++)
  68         bug("[META] Method ID 0x%08X function 0x%p\n", i, b->MethodTable[i].MethodFunc);
  69 }
  70
  71 #else
  72
  73 #define dump_bucket(b)
  74
  75 #endif
  76
  77 /********************
  78 **  IFMeta::New()  **
  79 ********************/
  80 static OOP_Object *ifmeta_new(OOP_Class *cl, OOP_Object *o, struct pRoot_New *msg)
  81 {
  82     struct IntOOPBase *OOPBase = (struct IntOOPBase *)cl->OOPBasePtr;
  83     struct Library *UtilityBase = OOPBase->ob_UtilityBase;
  84     IPTR (*domethod)(OOP_Object *, OOP_Msg) = NULL;
  85     IPTR (*coercemethod)(OOP_Class *, OOP_Object *, OOP_Msg)    = NULL;
  86     IPTR (*dosupermethod)(OOP_Class *, OOP_Object *, OOP_Msg)   = NULL;
  87
  88     EnterFunc(bug("IFMeta::New(cl=%s, (0x%p), msg = %p)\n",
  89         cl->ClassNode.ln_Name, cl, msg));
  90
  91     /* Let the BaseMeta class initialize some stuff for us */
  92     o = (OOP_Object *)OOP_DoSuperMethod((OOP_Class *)cl, o, (OOP_Msg)msg);
  93     D(bug("IFMeta: Superclass returned 0x%p\n", o));
  94
  95     if (o)
  96     {
  97
  98         struct ifmeta_inst *inst;
  99
 100         inst = (struct ifmeta_inst *)o;
 101
 102         domethod        = (IPTR (*)())GetTagData(aMeta_DoMethod,        0, msg->attrList);
 103         coercemethod    = (IPTR (*)())GetTagData(aMeta_CoerceMethod,    0, msg->attrList);
 104         dosupermethod   = (IPTR (*)())GetTagData(aMeta_DoSuperMethod,   0, msg->attrList);
 105
 106
 107         D(bug("Instance allocated %p\n", inst));
 108
 109
 110         if (!domethod)
 111             domethod = Meta_DoMethod;
 112
 113         if (!coercemethod)
 114             coercemethod = Meta_CoerceMethod;
 115
 116         if (!dosupermethod)
 117         {
 118
 119             OOP_Class *superptr = inst->base.public.superclass;
 120             if (superptr)
 121             {
 122                 D(bug("Got superptr: %p\n", superptr));
 123                 /* Use superclass' DoSupermethod call if superclass isn't
 124                     an instance of the HIDDMetaClass
 125                 */
 126                 if (OOP_OCLASS(superptr) != (OOP_Class *)cl)
 127                 {
 128                     D(bug("superptr has different meta\n"));
 129
 130                     dosupermethod = superptr->cl_DoSuperMethod;
 131                 }
 132                 else
 133                 {
 134                     D(bug("superptr has same meta\n"));
 135
 136                     dosupermethod = Meta_DoSuperMethod;
 137                 }
 138
 139             }
 140             else /* if (class has no superclass) */
 141             {
 142                 dosupermethod = NULL;
 143             }
 144
 145         }
 146
 147         inst->base.public.OOPBasePtr    = OOPBase;
 148
 149         inst->base.public.cl_DoMethod   = domethod;
 150         inst->base.public.cl_CoerceMethod       = coercemethod;
 151         inst->base.public.cl_DoSuperMethod      = dosupermethod;
 152
 153         D(bug("Classes' functions set\n"));
 154     }
 155
 156     ReturnPtr ("IFMeta::New", OOP_Object *, o);
 157 }
 158
 159 /******************************
 160 **  IFMeta::allocdisptabs()  **
 161 ******************************/
 162
 163 /* Allocates and initializes the interface hashtable, and the methodtables */
 164 static BOOL ifmeta_allocdisptabs(OOP_Class *cl, OOP_Object *o, struct P_meta_allocdisptabs *msg)
 165 {
 166     struct IntOOPBase *OOPBase = (struct IntOOPBase *)cl->OOPBasePtr;
 167     ULONG num_if;
 168
 169     struct ifmeta_inst *inst = (struct ifmeta_inst *)o;
 170
 171     EnterFunc(bug("IFMeta::allocdisptabs(cl=%p, o=%p,ifDescr=%p)\n",
 172         cl, o, msg->ifdescr));
 173
 174     /* Get number of needed hash entries */
 175     num_if = calc_ht_entries(inst, msg->superclass, msg->ifdescr, OOPBase);
 176
 177     inst->base.numinterfaces = num_if;
 178
 179     D(bug("numinterfaces set to %ld\n", num_if));
 180
 181     /* Create a new integer hashtable, with a reasonable size */
 182     inst->data.iftable = NewHash(num_if, HT_INTEGER, OOPBase);
 183     if (inst->data.iftable)
 184     {
 185         const struct OOP_InterfaceDescr *ifdescr;
 186
 187         D(bug("Got iftable\n"));
 188         /* Save hashmask for use in method lookup */
 189         inst->data.hashmask = HashMask(inst->data.iftable);
 190
 191         if (msg->superclass) /* This test makes it work for initializing root classes */
 192         {
 193
 194             /* Copy parent interfaces into the new class */
 195             struct IFMethod *superif;
 196             struct P_meta_iterateifs ii_msg;
 197             CONST_STRPTR interface_id;
 198             ULONG num_methods;
 199
 200             /* must be initialized to zero */
 201             IPTR iterval = 0UL;
 202
 203             D(bug("Adding superclass' methods\n"));
 204
 205             ii_msg.mid = OOP_GetMethodID(IID_Meta, MO_meta_iterateifs);
 206
 207             ii_msg.iterval_ptr          = &iterval;
 208             ii_msg.interface_id_ptr     = &interface_id;
 209             ii_msg.num_methods_ptr      = &num_methods;
 210
 211
 212             for (;;)
 213             {
 214                 struct IFBucket *ifb = NULL;
 215                 ULONG local_id = 0;
 216
 217                 superif = (struct IFMethod *)OOP_CoerceMethod(OOP_OCLASS(msg->superclass)
 218                                                              ,(OOP_Object *)msg->superclass
 219                                                              ,(OOP_Msg)&ii_msg);
 220                 if (!superif)
 221                     break;
 222
 223                 /* Get correct ID for the interface (string ID => interface ID mapping) */
 224                 if (init_mi_methodbase(interface_id, &local_id, OOPBase))
 225                 {
 226                     /* Allocate and insert the interface into the new class */
 227                     ifb = createbucket(interface_id, local_id, num_methods);
 228                 }
 229
 230                 if (!ifb)
 231                     goto failure;
 232
 233                 /* Copy the interface */
 234                 D(bug("[META] Copying from superclass methods for if %s, local ID 0x%08X, basmetaroot %p, superif %p\n",
 235                         ifb->GlobalInterfaceID, ifb->InterfaceID, OOPBase->ob_BaseMetaObject.inst.rootif, superif));
 236
 237                 CopyMem(superif, ifb->MethodTable, sizeof(struct IFMethod) * num_methods);
 238                 InsertBucket(inst->data.iftable, (struct Bucket *)ifb, OOPBase);
 239
 240             } /* for (;;) */
 241
 242         } /* if (we inherit interfaces from some superclass) */
 243
 244         /* Insert our own interfaces */
 245         D(bug("[META] Inserting own methods...\n"));
 246         for ( ifdescr = msg->ifdescr; ifdescr->MethodTable; ifdescr ++)
 247         {
 248             struct IFBucket *ifb;
 249             ULONG i;
 250             ULONG iid;
 251             ULONG num_methods = 0;
 252
 253             /* Get variable interface ID */
 254             D(bug("[META] Getting Local ifID for global ID %s\n", ifdescr->InterfaceID));
 255             if (!init_mi_methodbase(ifdescr->InterfaceID, &iid, OOPBase))
 256                 goto failure;
 257
 258             D(bug("[META] Got local ifID 0x%08X\n", iid));
 259
 260             /*
 261              * Count how many methods we are going to have in our interface.
 262              * Caller-supplied MethodTable in interface descriptor table may
 263              * have skipped entries (noone promised that it will cover the
 264              * whole range from 0 to maximum method offset). However our bucket's
 265              * MethodTable must cover the whole range, since method offset is an
 266              * index into this table (see Meta_CoerceMethod() below).
 267              * So we determine the largest offset and then add 1.
 268              *
 269              * v42.1 : ifdescr->NumMethods is completely ignored. This member is
 270              * actually redundant and not needed.
 271              */
 272             for (i = 0; ifdescr->MethodTable[i].MethodFunc; i++)
 273             {
 274                 if (ifdescr->MethodTable[i].MethodIdx > num_methods)
 275                     num_methods = ifdescr->MethodTable[i].MethodIdx;
 276             }
 277
 278             num_methods++;
 279             D(bug("[META] Interface will have %u methods\n", num_methods));
 280
 281             /* Lookup hashtable to see if interface has been copied from superclass */
 282             ifb = (struct IFBucket *)inst->data.iftable->Lookup(
 283                           inst->data.iftable
 284                         , (IPTR)iid
 285                         , OOPBase);
 286
 287             D(bug("[META] tried to find bucket in hashtable: 0x%p\n", ifb));
 288             if (!ifb)
 289             {
 290                 D(bug("[META] Bucket doesn't exist, creating...\n"));
 291
 292                 /* Bucket doesn't exist, allocate it */
 293                 ifb = createbucket(ifdescr->InterfaceID, iid, num_methods);
 294                 if (!ifb)
 295                     goto failure;
 296                 else
 297                 {
 298                     D(bug("[META] Inserting bucket 0x%p for IF %s\n", ifb, ifdescr->InterfaceID));
 299                     InsertBucket(inst->data.iftable, (struct Bucket *)ifb, OOPBase);
 300                 }
 301             }
 302             else if (ifb->NumMethods < num_methods)
 303             {
 304                 D(bug("[META] Current bucket has %u methods, expanding...\n", ifb->NumMethods));
 305
 306                 if (!expandbucket(ifb, num_methods))
 307                     goto failure;
 308             }
 309
 310             D(bug("[META] overriding methods...\n"));
 311
 312             /* Ovveride the superclass methods with our new ones */
 313             for (i = 0; ifdescr->MethodTable[i].MethodFunc; i ++)
 314             {
 315                 D(bug("[META] Method ID 0x%08X function 0x%p\n", ifdescr->MethodTable[i].MethodIdx, ifdescr->MethodTable[i].MethodFunc));
 316
 317                 ifb->MethodTable[ ifdescr->MethodTable[i].MethodIdx ].MethodFunc = ifdescr->MethodTable[i].MethodFunc;
 318                 ifb->MethodTable[ ifdescr->MethodTable[i].MethodIdx ].mClass     = (OOP_Class *)o;
 319             } /* for (each method in the interface) */
 320
 321         } /* for (each interface to add to class) */
 322
 323         /* For speedup in method lookup */
 324         inst->data.iftab_directptr = (struct IFBucket **)inst->data.iftable->Table;
 325
 326         ReturnBool ("IFMeta::allocdisptabs", TRUE);
 327
 328     } /* if (interface hash table allocated) */
 329
 330 failure:
 331     D(bug("FAILURE\n"));
 332     if (inst->data.iftable)
 333         FreeHash(inst->data.iftable, freebucket, OOPBase);
 334     ReturnBool ("IFMeta::allocdisptabs", FALSE);
 335 }
 336
 337 /*****************************
 338 **  IFMeta::freedisptabs()  **
 339 *****************************/
 340 static VOID ifmeta_freedisptabs(OOP_Class *cl, OOP_Object *o, OOP_Msg msg)
 341
 342 {
 343     struct IntOOPBase *OOPBase = (struct IntOOPBase *)cl->OOPBasePtr;
 344     struct ifmeta_inst *inst = (struct ifmeta_inst *)o;
 345     /* This frees the hashtable + all buckets */
 346
 347     FreeHash(inst->data.iftable, freebucket, OOPBase);
 348
 349     return;
 350 }
 351
 352 /**************************
 353 **  IFMeta::getifinfo()  **
 354 **************************/
 355 static struct IFMethod *ifmeta_getifinfo(OOP_Class *cl, OOP_Object *o, struct P_meta_getifinfo *msg)
 356 {
 357     struct IntOOPBase *OOPBase = (struct IntOOPBase *)cl->OOPBasePtr;
 358     ULONG iid;
 359     struct ifmeta_inst *inst = (struct ifmeta_inst *)o;
 360     struct IFMethod *mtab = NULL;
 361     struct IFBucket *b;
 362
 363     /* Get the ULONG variable interface id */
 364     iid = OOP_GetMethodID(msg->interface_id, 0);
 365
 366     /* Try looking it up in the class' table */
 367     b = (struct IFBucket *)inst->data.iftable->Lookup(inst->data.iftable, (IPTR)iid, OOPBase);
 368     {
 369         *(msg->num_methods_ptr) = b->NumMethods;
 370
 371         mtab = b->MethodTable;
 372     }
 373
 374     return mtab;
 375 }
 376
 377 /***************************
 378 **  IFMeta::iterateifs()  **
 379 ***************************/
 380 static struct IFMethod *ifmeta_iterateifs(OOP_Class *cl, OOP_Object *o, struct P_meta_iterateifs *msg)
 381 {
 382     struct HashTable *ht = ((struct ifmeta_inst *)o)->data.iftable;
 383     struct IFBucket *found_bucket = NULL; /* MUST default to NULL */
 384
 385     struct IFBucket *ifb = NULL; /* keep compiler happy */
 386
 387
 388     struct IFMethod *current_if = NULL;     /* MUST default to NULL */
 389
 390     UWORD last_idx = (*(msg->iterval_ptr)) >> 16;
 391     UWORD last_bucket_no = (*(msg->iterval_ptr)) & 0x0000FFFF;
 392
 393     UWORD idx;
 394
 395     UWORD bucket_no = 0; /* keep compiler happy */
 396     EnterFunc(bug("IFMeta::iterateifs(cl=%s, o=%s)\n",
 397         cl->ClassNode.ln_Name, ((OOP_Class *)o)->ClassNode.ln_Name ));
 398
 399     D(bug("last_idx: %ld, last_bucket_no=%ld\n", last_idx, last_bucket_no));
 400
 401
 402     for (idx = last_idx ;idx < HashSize(ht); idx ++)
 403     {
 404         D(bug("idx=%ld\n", idx));
 405
 406         bucket_no = 0;
 407
 408         for (ifb = (struct IFBucket *)ht->Table[idx]; ifb; )
 409         {
 410             D(bug("ifb=%s, netx=%p, bucket_no=%ld\n",
 411                 ifb->GlobalInterfaceID, ifb->Next, bucket_no));
 412             /* Is this a new bucket in the iteration ? */
 413
 414             if ((idx > last_idx) || (bucket_no >= last_bucket_no))
 415             {
 416                 found_bucket = ifb;
 417
 418                 /* Yes, it's a goto, but it really simplifies things here */
 419                 goto after_loop;
 420             }
 421             else
 422             {
 423                 ifb = ifb->Next;
 424                 bucket_no ++;
 425             }
 426
 427         } /* for (all buckets at each idx) */
 428
 429     } /* for (each entry at east index from last idx) */
 430
 431 after_loop:
 432
 433     /* OK, found a bucket ? */
 434     if (found_bucket)
 435     {
 436         D(bug("bucket found: %s at idx %ld, b_no %ld\n",
 437                 found_bucket->GlobalInterfaceID, idx, bucket_no));
 438         *(msg->iterval_ptr)      = (idx << 16) + bucket_no + 1;
 439         *(msg->interface_id_ptr) = ifb->GlobalInterfaceID;
 440         *(msg->num_methods_ptr)  = ifb->NumMethods;
 441
 442         current_if = ifb->MethodTable;
 443     }
 444
 445     ReturnPtr ("IFMeta::iterateifs", struct IFMethod *, current_if);
 446 }
 447
 448 /***************************
 449 **  IFMeta::findmethod()  **
 450 ***************************/
 451
 452 /* Used for finding a method for method objects */
 453 static struct IFMethod *ifmeta_findmethod(OOP_Class *cl, OOP_Object *o, struct P_meta_findmethod *msg)
 454 {
 455     register struct IFBucket *b;
 456     register ULONG method_offset;
 457     struct ifmeta_inst *inst = (struct ifmeta_inst *)o;
 458
 459     /* Get interfaceID part of methodID */
 460     register ULONG ifid = msg->method_to_find & (~METHOD_MASK);
 461
 462     EnterFunc(bug("IFMeta::findmethod(o=%p, mid=%ld)\n", o, msg->method_to_find));
 463
 464
 465     /* Get method offset part of methdoID */
 466     method_offset =  msg->method_to_find & METHOD_MASK;
 467
 468     /* Look up ID in hashtable and get linked list of buckets,
 469        storing interfaces
 470     */
 471     b = inst->data.iftab_directptr[ifid & inst->data.hashmask];
 472 loop:
 473     if (b)
 474     {
 475         /* Found correct interface ? */
 476         if (b->InterfaceID == ifid)
 477         {
 478             /* Yep. Return method at supplied method offset */
 479             ReturnPtr ("IFMeta::findmethod", struct IFMethod *, &(b->MethodTable[method_offset]));
 480         }
 481
 482         b = b->Next;
 483         goto loop;
 484     }
 485     /* Method not found, return NULL */
 486     ReturnPtr ("IFMeta::findmethod", struct IFMethod *, NULL);
 487
 488 }
 489
 490 /**********
 491   Support
 492 **********/
 493
 494 /*************************
 495 **  init_ifmetaclass()  **
 496 *************************/
 497
 498 #define NUM_META_METHODS 5
 499 #define NUM_ROOT_METHODS 1
 500
 501 static const struct OOP_MethodDescr root_mdescr[NUM_ROOT_METHODS + 1]=
 502 {
 503     { (IPTR (*)())ifmeta_new,   moRoot_New              },
 504     {  NULL, 0UL }
 505 };
 506
 507 static const struct OOP_MethodDescr meta_mdescr[NUM_META_METHODS + 1]=
 508 {
 509     { (IPTR (*)())ifmeta_allocdisptabs, MO_meta_allocdisptabs   },
 510     { (IPTR (*)())ifmeta_freedisptabs,  MO_meta_freedisptabs    },
 511     { (IPTR (*)())ifmeta_getifinfo,     MO_meta_getifinfo       },
 512     { (IPTR (*)())ifmeta_iterateifs,    MO_meta_iterateifs      },
 513     { (IPTR (*)())ifmeta_findmethod,    MO_meta_findmethod      },
 514     {  NULL, 0 }
 515 };
 516
 517 static const struct OOP_InterfaceDescr meta_descr[] =
 518 {
 519     {root_mdescr, IID_Root, NUM_ROOT_METHODS},
 520     {meta_mdescr, IID_Meta, NUM_META_METHODS},
 521     {NULL, NULL, 0UL}
 522 };
 523
 524 BOOL init_ifmetaclass(struct IntOOPBase *OOPBase)
 525 {
 526
 527     struct ifmetaobject *imo = &(OOPBase->ob_IFMetaObject);
 528     struct P_meta_allocdisptabs adt_msg;
 529     OOP_Class *ifmeta_cl;
 530
 531     EnterFunc(bug("init_ifmetaclass()\n"));
 532
 533     ifmeta_cl = &(imo->inst.base.public);
 534
 535     D(bug("Got ifmeta classptr 0x%p\n", ifmeta_cl));
 536
 537     imo->inst.base.public.superclass = BASEMETAPTR;
 538     imo->inst.base.public.OOPBasePtr = OOPBase;
 539
 540     D(bug("Initialized ifmeta superclass 0x%p\n", imo->inst.base.public.superclass));
 541
 542     adt_msg.superclass = imo->inst.base.public.superclass;
 543     adt_msg.ifdescr = meta_descr;
 544
 545     /* allocdisptabs() must know the OOPBase */
 546     imo->inst.base.public.UserData              = (APTR)OOPBase;
 547     /* It must also have a valid DoSuperMethod(), more exatly
 548        the DoSuperMethod() of the BaseMeta class
 549     */
 550     imo->inst.base.public.cl_DoSuperMethod = BASEMETAPTR->cl_DoSuperMethod;
 551
 552     D(bug("Allocating ifmeta disptabs\n"));
 553
 554     if (ifmeta_allocdisptabs(ifmeta_cl, (OOP_Object *)ifmeta_cl, &adt_msg))
 555     {
 556         D(bug("ifmeta disptabs allocated\n"));
 557         /* initialize Class ID */
 558
 559         imo->inst.base.public.ClassNode.ln_Name = CLID_MIMeta;
 560         imo->inst.base.public.InstOffset        = sizeof (struct metadata);
 561
 562         D(bug("IFMeta DoMethod=%p\n", Meta_DoMethod));
 563         imo->inst.base.public.cl_DoMethod               = Meta_DoMethod;
 564         imo->inst.base.public.cl_CoerceMethod   = Meta_CoerceMethod;
 565
 566         imo->inst.base.instsize   = sizeof (struct ifmeta_data);
 567         imo->inst.base.subclasscount    = 0UL;
 568         imo->inst.base.objectcount      = 0UL;
 569
 570         imo->inst.data.numinterfaces    = 2UL;
 571
 572         /* This class' class is itself */
 573         imo->oclass = &(imo->inst.base.public);
 574
 575 /*      {
 576            ULONG i;
 577            D(bug("Trying to call get_if_info on ifmeta many times\n"));
 578            for (i = 0; i < 10; i ++)
 579            {
 580                 ULONG num_methods;
 581                 meta_getifinfo((OOP_Object *)imo->oclass, IID_Meta, &num_methods);
 582
 583                 D(bug("IF has %ld methods\n", num_methods));
 584            }
 585
 586         }
 587 */      /* Make it public */
 588         OOP_AddClass(ifmeta_cl);
 589         ReturnBool ("init_metaclass", TRUE);
 590     }
 591     ReturnBool ("init_ifmetaclass", FALSE);
 592
 593 }
 594
 595
 596 /************************
 597 **  calc_ht_entries()  **
 598 ************************/
 599
 600 /* Calculates the number of interfaces the new class has
 601    ( == number of buckets in the hashtable)
 602 */
 603 static ULONG calc_ht_entries(struct ifmeta_inst *cl ,OOP_Class *super,
 604                              const struct OOP_InterfaceDescr *ifDescr, struct IntOOPBase *OOPBase)
 605 {
 606     ULONG num_if = 0;
 607
 608     EnterFunc(bug("calc_ht_entries(cl=%p, ifDescr=%p, super=%p)\n", cl, ifDescr, super));
 609
 610     if (super)
 611     {
 612         /* Get number of interfaces (method tables) in superclass */
 613
 614         num_if = MD(super)->numinterfaces;
 615
 616         D(bug("Super-interfaces: %ld\n", num_if));
 617
 618         /* Check if there are any new interfaces in this class */
 619
 620         for (; ifDescr->MethodTable; ifDescr ++)
 621         {
 622             struct P_meta_getifinfo gii_msg;
 623             ULONG num_methods;
 624
 625             D(bug("Checking for interface %s\n", ifDescr->InterfaceID));
 626
 627             gii_msg.mid = OOP_GetMethodID(IID_Meta, MO_meta_getifinfo);
 628             gii_msg.interface_id = ifDescr->InterfaceID;
 629             gii_msg.num_methods_ptr = &num_methods;
 630
 631
 632             /* Does super support interface ? */
 633             D(bug("Calling CoerceMethod on class %s\n", OOP_OCLASS(super)->ClassNode.ln_Name));
 634             if (!OOP_CoerceMethod(OOP_OCLASS(super), (OOP_Object *)super, (OOP_Msg)&gii_msg))
 635             {
 636                 D(bug("Found new interface: %s\n", ifDescr->InterfaceID));
 637
 638                 /* If it didn't then we have a new interface for this class */
 639                 num_if ++;
 640             }
 641
 642         } /* for (each interface in the description for the class) */
 643
 644     }
 645     else
 646     {
 647         /* This is a baseclass, count the interfaces */
 648         for (; ifDescr->MethodTable; ifDescr ++)
 649         {
 650             num_if ++;
 651
 652         } /* for (each interface in the description for the class) */
 653     }
 654     ReturnInt ("calc_ht_entries", ULONG, num_if);
 655 }
 656
 657 /*********************
 658 **  createbucket()  **
 659 *********************/
 660 /* Creates a new interface bucket */
 661 static struct IFBucket *createbucket(CONST_STRPTR interface_id, ULONG local_id, ULONG num_methods)
 662 {
 663     /* Allocate bucket */
 664     struct IFBucket *ifb;
 665
 666     ifb = AllocMem(sizeof (struct IFBucket), MEMF_ANY);
 667     if (ifb)
 668     {
 669         /* Allocate method table for this interface */
 670         ifb->MethodTable = AllocVec(sizeof(struct IFMethod) * num_methods, MEMF_CLEAR);
 671         if (ifb->MethodTable)
 672         {
 673             /* Set correct ID for the interface (string ID => interface ID mapping) */
 674             ifb->InterfaceID       = local_id;
 675             ifb->GlobalInterfaceID = interface_id;
 676
 677             /* Save number of methods in the interface */
 678             ifb->NumMethods = num_methods;
 679
 680             D(bug("[META] Created bucket 0x%p for %u methods\n", ifb, num_methods));
 681             return ifb;
 682         }
 683         FreeMem(ifb, sizeof (struct IFBucket));
 684     }
 685     return NULL;
 686 }
 687
 688 /***********************
 689 **  Hash table hooks  **
 690 ***********************/
 691 #define IB(x) ((struct IFBucket *)x)
 692
 693 VOID freebucket(struct Bucket *b, struct IntOOPBase *OOPBase)
 694 {
 695     D(bug("[META] freebucket(0x%p)\n", b));
 696
 697     /* Free methodtable */
 698     FreeVec(IB(b)->MethodTable);
 699
 700     /* Free the bucket itself */
 701     FreeMem(b, sizeof (struct IFBucket));
 702
 703
 704     return;
 705 }
 706
 707 /* Copies a hashtable bucket */
 708 struct Bucket *copyBucket(struct Bucket *old_b, APTR data, struct IntOOPBase *OOPBase)
 709 {
 710     struct IFBucket *new_b;
 711
 712     EnterFunc(bug("CopyBucket(old_b=%p)\n", old_b));
 713
 714     /* Allocate the new interface bucket */
 715     new_b = createbucket(IB(old_b)->GlobalInterfaceID, IB(old_b)->InterfaceID, IB(old_b)->NumMethods);
 716
 717     if (new_b)
 718         /* Copy methodtable to destination */
 719         CopyMem(IB(old_b)->MethodTable, new_b->MethodTable,  sizeof(struct IFMethod) * IB(old_b)->NumMethods);
 720
 721     ReturnPtr ("CopyBucket", struct Bucket *, (struct Bucket *)new_b );
 722 }
 723
 724 /* Expand method table in IFBucket up to num_methods entries */
 725 static BOOL expandbucket(struct IFBucket *b, ULONG num_methods)
 726 {
 727     struct IFMethod *ifm = AllocVec(sizeof(struct IFMethod) * num_methods, MEMF_CLEAR);
 728
 729     if (!ifm)
 730         return FALSE;
 731
 732     CopyMem(b->MethodTable, ifm, sizeof(struct IFMethod) * b->NumMethods);
 733     FreeVec(b->MethodTable);
 734     b->MethodTable = ifm;
 735
 736     return TRUE;
 737 }
 738
 739 /* Default function for calling DoMethod() on a local object */
 740 /*****************
 741 **  DoMethod()  **
 742 *****************/
 743
 744 static IPTR Meta_DoMethod(OOP_Object *object, OOP_Msg msg)
 745 {
 746     D(bug("[META] DoMethod(0x%p), class 0x%p\n", object, OOP_OCLASS(object)));
 747
 748     return Meta_CoerceMethod(OOP_OCLASS(object), object, msg);
 749 }
 750
 751 /*******************
 752 **  CoerceMethod  **
 753 *******************/
 754 static IPTR Meta_CoerceMethod(OOP_Class *cl, OOP_Object *o, OOP_Msg msg)
 755 {
 756     register struct IFBucket *b;
 757     register OOP_MethodID mid = *msg;
 758     register ULONG ifid = mid & (~METHOD_MASK);
 759
 760     mid &= METHOD_MASK;
 761
 762     b = IFI(cl)->data.iftab_directptr[ifid & IFI(cl)->data.hashmask];
 763     while (b)
 764     {
 765         if (b->InterfaceID == ifid)
 766         {
 767             dump_bucket(b);
 768
 769             /* Ensure that method offset fits into the table */
 770             if (mid < b->NumMethods)
 771             {
 772                 register struct IFMethod *method = &b->MethodTable[mid];
 773
 774                 if (method->MethodFunc)
 775                     return method->MethodFunc(method->mClass, o, msg);
 776             }
 777
 778             /*
 779              * TODO: Looks like it would be nice to post alerts with some extra information
 780              * attached.
 781              * Current exec.library API does not allow this. Need to invent something.
 782              */
 783             bug("[OOP metaclass] Unimplemented method 0x%08X called on class 0x%p (%s)\n", mid, cl, cl->ClassNode.ln_Name);
 784             bug("[OOP metaclass] Interface ID %s\n", b->GlobalInterfaceID);
 785             bug("[OOP metaclass] Object 0x%p\n", o);
 786
 787             /*
 788              * Throw an alert. It is recoverable, so won't harm.
 789              * But the developer will be able to examine a stack trace.
 790              */
 791             Alert(AN_OOP);
 792
 793             return 0;
 794         }
 795         b = b->Next;
 796     }
 797
 798     return 0;
 799 }
 800
 801 /********************
 802 **  DoSuperMethod  **
 803 ********************/
 804 static IPTR Meta_DoSuperMethod(OOP_Class *cl, OOP_Object *object, OOP_Msg msg)
 805 {
 806     return Meta_CoerceMethod(IFI(cl)->base.public.superclass, object, msg);
 807 }