5 /* support for Hash::Util::FieldHash, prefix HUF_ */
7 /* A Perl sub that returns a hashref to the object registry */
8 #define HUF_OB_REG "Hash::Util::FieldHash::_ob_reg"
9 /* Magic cookies to recognize object id's. Hi, Eva, David */
10 #define HUF_COOKIE 2805.1980
11 #define HUF_REFADDR_COOKIE 1811.1976
12 /* Identifier for PERL_MAGIC_ext magic */
13 #define HUF_IDCACHE 0x4944
15 /* For global cache of object registry */
16 #define MY_CXT_KEY "Hash::Util::FieldHash::_guts" XS_VERSION
18 HV* ob_reg; /* Cache object registry */
22 /* Inquire the object registry (a lexical hash) from perl */
23 HV* HUF_get_ob_reg(void) {
31 items = call_pv(HUF_OB_REG, G_SCALAR|G_NOARGS);
34 if (items == 1 && TOPs && SvROK(TOPs) && SvTYPE(SvRV(TOPs)) == SVt_PVHV)
35 ob_reg = (HV*)SvRV(POPs);
41 Perl_die(aTHX_ "Can't get object registry hash");
45 /* Deal with global context */
50 void HUF_global(I32 how) {
51 if (how == HUF_INIT) {
53 MY_CXT.ob_reg = HUF_get_ob_reg();
54 } else if (how == HUF_CLONE) {
56 MY_CXT.ob_reg = HUF_get_ob_reg();
57 } else if (how == HUF_RESET) {
59 MY_CXT.ob_reg = HUF_get_ob_reg();
65 /* definition of id transformation */
66 #define HUF_OBJ_ID(x) newSVuv(PTR2UV(x))
68 SV* HUF_obj_id(SV* obj) {
73 /* Get cached object ID, if it exists */
74 if (SvTYPE(item) >= SVt_PVMG) {
75 for ( mg = SvMAGIC(item); mg; mg = mg->mg_moremagic ) {
76 if ((mg->mg_type == PERL_MAGIC_ext) &&
77 (mg->mg_private == HUF_IDCACHE)
84 /* Create an object ID, cache it */
85 id = HUF_OBJ_ID(item);
86 mg = sv_magicext(item, id, PERL_MAGIC_ext, NULL, NULL, 0);
87 mg->mg_private = HUF_IDCACHE;
89 /* Return the object ID */
93 /* set up uvar magic for any sv */
94 void HUF_add_uvar_magic(
95 SV* sv, /* the sv to enchant, visible to get/set */
96 I32(* val)(pTHX_ IV, SV*), /* "get" function */
97 I32(* set)(pTHX_ IV, SV*), /* "set" function */
98 I32 index, /* get/set will see this */
99 SV* thing /* any associated info */
105 sv_magic(sv, thing, PERL_MAGIC_uvar, (char*)&uf, sizeof(uf));
108 /* Fetch the data container of a trigger */
109 AV* HUF_get_trigger_content(SV* trigger) {
111 if (trigger && (mg = mg_find(trigger, PERL_MAGIC_uvar)))
112 return (AV*)mg->mg_obj;
116 /* Delete an object from all field hashes it may occur in. Also delete
117 * the object's entry from the object registry. This function goes in
118 * the uf_set field of the uvar magic of a trigger.
120 I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
121 /* Do nothing if the weakref wasn't undef'd. Also don't bother
122 * during global destruction. (MY_CXT.ob_reg is sometimes funny there) */
123 if (!SvROK(trigger) && (!PL_in_clean_all)) {
125 AV* cont = HUF_get_trigger_content(trigger);
126 SV* ob_id = *av_fetch(cont, 0, 0);
127 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
129 hv_iterinit(field_tab);
130 while (ent = hv_iternext(field_tab)) {
131 SV* field_ref = HeVAL(ent);
132 SV* field = SvRV(field_ref);
133 hv_delete_ent((HV*)field, ob_id, G_DISCARD, 0);
135 /* make it safe in case we must run in global clenaup, after all */
137 HUF_global(HUF_RESET); /* shoudn't be needed */
138 hv_delete_ent(MY_CXT.ob_reg, ob_id, G_DISCARD, 0);
143 /* Create a trigger for an object. The trigger is a magical SV
144 * that holds a weak ref to the object. The magic fires when the object
145 * expires and takes care of garbage collection in registred hashes.
146 * For that purpose, the magic structure holds the original id of
147 * the object, and a list (a hash, really) of hashes from which the
148 * object may * have to be deleted. The trigger is stored in the
149 * object registry and is also deleted when the object expires.
151 SV* HUF_new_trigger(SV* obj, SV* ob_id) {
153 SV* trigger = sv_rvweaken(newRV_inc(SvRV(obj)));
155 sv_2mortal((SV*)cont);
156 av_store(cont, 0, SvREFCNT_inc(ob_id));
157 av_store(cont, 1, (SV*)newHV());
158 HUF_add_uvar_magic(trigger, NULL, &HUF_destroy_obj, 0, (SV*)cont);
159 hv_store_ent(MY_CXT.ob_reg, ob_id, trigger, 0);
163 /* retrieve a trigger for obj if one exists, return NULL otherwise */
164 SV* HUF_ask_trigger(SV* ob_id) {
167 if (ent = hv_fetch_ent(MY_CXT.ob_reg, ob_id, 0, 0))
172 /* get the trigger for an object, creating it if necessary */
173 SV* HUF_get_trigger0(SV* obj, SV* ob_id) {
175 if (!(trigger = HUF_ask_trigger(ob_id)))
176 trigger = HUF_new_trigger(obj, ob_id);
180 SV* HUF_get_trigger(SV* obj, SV* ob_id) {
181 SV* trigger = HUF_ask_trigger(ob_id);
183 trigger = HUF_new_trigger(obj, ob_id);
187 /* mark an object (trigger) as having been used with a field
190 void HUF_mark_field(SV* trigger, SV* field) {
191 AV* cont = HUF_get_trigger_content(trigger);
192 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
193 SV* field_ref = newRV_inc(field);
194 UV field_addr = PTR2UV(field);
195 hv_store(field_tab, (char *)&field_addr, sizeof(field_addr), field_ref, 0);
198 /* Determine, from the value of action, whether this call may create a new
200 #define HUF_WOULD_CREATE_KEY(x) ((x) != HV_DELETE && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
202 /* The key exchange functions. They communicate with S_hv_magic_uvar_xkey
204 I32 HUF_watch_key_safe(pTHX_ IV action, SV* field) {
205 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
207 if (mg && (keysv = mg->mg_obj)) {
208 if (SvROK(keysv)) { /* ref key */
209 SV* ob_id = HUF_obj_id(keysv);
210 mg->mg_obj = ob_id; /* key replacement */
211 if (HUF_WOULD_CREATE_KEY(action)) {
212 SV* trigger = HUF_get_trigger(keysv, ob_id);
213 HUF_mark_field(trigger, field);
215 } else if (HUF_WOULD_CREATE_KEY(action)) { /* string key */
216 /* registered as object id? */
218 if ( trigger = HUF_ask_trigger(keysv))
219 HUF_mark_field( trigger, field);
222 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_safe'");
227 I32 HUF_watch_key_id(pTHX_ IV action, SV* field) {
228 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
230 if (mg && (keysv = mg->mg_obj)) {
231 if (SvROK(keysv)) /* ref key */
232 mg->mg_obj = HUF_obj_id(keysv); /* key replacement */
234 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_id'");
239 int HUF_func_2mode( I32(* val)(pTHX_ IV, SV*)) {
241 if (val == &HUF_watch_key_id)
243 if (val == &HUF_watch_key_safe)
248 I32(* HUF_mode_2func( int mode))(pTHX_ IV, SV*) {
249 I32(* ans)(pTHX_ IV, SV*) = NULL;
252 ans = &HUF_watch_key_id;
255 ans = &HUF_watch_key_safe;
261 /* see if something is a field hash */
262 int HUF_get_status(HV* hash) {
264 if (hash && (SvTYPE(hash) == SVt_PVHV)) {
267 if ((mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
268 (uf = (struct ufuncs *)mg->mg_ptr) &&
271 ans = HUF_func_2mode(uf->uf_val);
277 /* Thread support. These routines are called by CLONE (and nothing else) */
279 /* Fix entries for one object in all field hashes */
280 void HUF_fix_trigger(SV* trigger, SV* new_id) {
281 AV* cont = HUF_get_trigger_content(trigger);
282 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
283 HV* new_tab = newHV();
285 SV* old_id = *av_fetch(cont, 0, 0);
286 hv_iterinit(field_tab);
287 while (ent = hv_iternext(field_tab)) {
288 SV* field_ref = HeVAL(ent);
289 HV* field = (HV*)SvRV(field_ref);
290 UV field_addr = PTR2UV(field);
292 /* recreate field tab entry */
293 hv_store(new_tab, (char *)&field_addr, sizeof(field_addr), SvREFCNT_inc(field_ref), 0);
294 /* recreate field entry, if any */
295 if (val = hv_delete_ent(field, old_id, 0, 0))
296 hv_store_ent(field, new_id, SvREFCNT_inc(val), 0);
298 /* update the trigger */
299 av_store(cont, 0, SvREFCNT_inc(new_id));
300 av_store(cont, 1, (SV*)new_tab);
303 /* Go over object registry and fix all objects. Also fix the object
306 void HUF_fix_objects(void) {
310 AV* oblist = (AV*)sv_2mortal((SV*)newAV());
311 hv_iterinit(MY_CXT.ob_reg);
312 while(ent = hv_iternext(MY_CXT.ob_reg))
313 av_push(oblist, SvREFCNT_inc(hv_iterkeysv(ent)));
314 len = av_len(oblist);
315 for (i = 0; i <= len; ++i) {
316 SV* old_id = *av_fetch(oblist, i, 0);
317 SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0);
318 SV* obj = SvRV(trigger);
321 SV* new_id = HUF_OBJ_ID(obj);
323 /* Replace cached object ID with this new one */
324 for (mg = SvMAGIC(obj); mg; mg = mg->mg_moremagic) {
325 if ((mg->mg_type == PERL_MAGIC_ext) &&
326 (mg->mg_private == HUF_IDCACHE)
332 HUF_fix_trigger(trigger, new_id);
333 hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0);
337 /* test support (not needed for functionality) */
340 I32 HUF_inc_var(pTHX_ IV index, SV* which) {
341 sv_setiv(counter, 1 + SvIV(counter));
345 MODULE = Hash::Util::FieldHash PACKAGE = Hash::Util::FieldHash
349 HUF_global(HUF_INIT); /* create variables */
353 _fieldhash(SV* href, int mode)
359 href && SvROK(href) &&
360 (field = (HV*)SvRV(href)) &&
361 SvTYPE(field) == SVt_PVHV
366 HUF_mode_2func( mode),
371 RETVAL = HUF_get_status(field);
380 XPUSHs(HUF_obj_id(ref));
389 SV* obj = HUF_ask_trigger(id);
391 RETVAL = newRV_inc(SvRV(obj));
393 RETVAL = &PL_sv_undef;
399 register(SV* obj, ...)
406 Perl_die(aTHX_ "Attempt to register a non-ref");
408 RETVAL = newRV_inc(SvRV(obj));
410 trigger = HUF_get_trigger(obj, HUF_obj_id(obj));
411 for (i = 1; i < items; ++ i) {
412 SV* field_ref = POPs;
413 if (SvROK(field_ref) && (SvTYPE(SvRV(field_ref)) == SVt_PVHV)) {
414 HUF_mark_field(trigger, SvRV(field_ref));
421 CLONE(char* classname)
423 if (0 == strcmp(classname, "Hash::Util::FieldHash")) {
424 HUF_global(HUF_CLONE);
429 _active_fields(SV* obj)
432 SV* ob_id = HUF_obj_id(obj);
433 SV* trigger = HUF_ask_trigger(ob_id);
435 AV* cont = HUF_get_trigger_content(trigger);
436 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
438 hv_iterinit(field_tab);
439 while (ent = hv_iternext(field_tab)) {
440 HV* field = (HV*)SvRV(HeVAL(ent));
441 if (hv_exists_ent(field, ob_id, 0))
442 XPUSHs(sv_2mortal(newRV_inc((SV*)field)));
448 _test_uvar_get(SV* svref, SV* countref)
450 if (SvROK(svref) && SvROK(countref)) {
451 counter = SvRV(countref);
452 sv_setiv(counter, 0);
463 _test_uvar_set(SV* svref, SV* countref)
465 if (SvROK(svref) && SvROK(countref)) {
466 counter = SvRV(countref);
467 sv_setiv(counter, 0);
468 counter = SvRV(countref);
479 _test_uvar_same(SV* svref, SV* countref)
481 if (SvROK(svref) && SvROK(countref)) {
482 counter = SvRV(countref);
483 sv_setiv(counter, 0);