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 /* Identifier for PERL_MAGIC_ext magic */
10 #define HUF_IDCACHE 0x4944
12 /* For global cache of object registry */
13 #define MY_CXT_KEY "Hash::Util::FieldHash::_guts" XS_VERSION
15 HV* ob_reg; /* Cache object registry */
19 /* Inquire the object registry (a lexical hash) from perl */
20 HV* HUF_get_ob_reg(void) {
28 items = call_pv(HUF_OB_REG, G_SCALAR|G_NOARGS);
31 if (items == 1 && TOPs && SvROK(TOPs) && SvTYPE(SvRV(TOPs)) == SVt_PVHV)
32 ob_reg = (HV*)SvRV(POPs);
38 Perl_die(aTHX_ "Can't get object registry hash");
42 /* Deal with global context */
47 void HUF_global(I32 how) {
48 if (how == HUF_INIT) {
50 MY_CXT.ob_reg = HUF_get_ob_reg();
51 } else if (how == HUF_CLONE) {
53 MY_CXT.ob_reg = HUF_get_ob_reg();
54 } else if (how == HUF_RESET) {
56 MY_CXT.ob_reg = HUF_get_ob_reg();
62 /* definition of id transformation */
63 #define HUF_OBJ_ID(x) newSVuv(PTR2UV(x))
65 SV* HUF_obj_id(SV* obj) {
70 /* Get cached object ID, if it exists */
71 if (SvTYPE(item) >= SVt_PVMG) {
72 for ( mg = SvMAGIC(item); mg; mg = mg->mg_moremagic ) {
73 if ((mg->mg_type == PERL_MAGIC_ext) &&
74 (mg->mg_private == HUF_IDCACHE)
81 /* Create an object ID, cache it */
82 id = HUF_OBJ_ID(item);
83 mg = sv_magicext(item, id, PERL_MAGIC_ext, NULL, NULL, 0);
84 mg->mg_private = HUF_IDCACHE;
85 SvREFCNT_dec(id); /* refcnt++ in sv_magicext() */
87 /* Return the object ID */
91 /* set up uvar magic for any sv */
92 void HUF_add_uvar_magic(
93 SV* sv, /* the sv to enchant, visible to get/set */
94 I32(* val)(pTHX_ IV, SV*), /* "get" function */
95 I32(* set)(pTHX_ IV, SV*), /* "set" function */
96 I32 index, /* get/set will see this */
97 SV* thing /* any associated info */
103 sv_magic(sv, thing, PERL_MAGIC_uvar, (char*)&uf, sizeof(uf));
106 /* Fetch the data container of a trigger */
107 AV* HUF_get_trigger_content(SV* trigger) {
109 if (trigger && (mg = mg_find(trigger, PERL_MAGIC_uvar)))
110 return (AV*)mg->mg_obj;
114 /* Delete an object from all field hashes it may occur in. Also delete
115 * the object's entry from the object registry. This function goes in
116 * the uf_set field of the uvar magic of a trigger.
118 I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
119 /* Do nothing if the weakref wasn't undef'd. Also don't bother
120 * during global destruction. (MY_CXT.ob_reg is sometimes funny there) */
121 if (!SvROK(trigger) && (!PL_in_clean_all)) {
123 AV* cont = HUF_get_trigger_content(trigger);
124 SV* ob_id = *av_fetch(cont, 0, 0);
125 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
127 hv_iterinit(field_tab);
128 while (ent = hv_iternext(field_tab)) {
129 SV* field_ref = HeVAL(ent);
130 SV* field = SvRV(field_ref);
131 hv_delete_ent((HV*)field, ob_id, 0, 0);
133 /* make it safe in case we must run in global clenaup, after all */
135 HUF_global(HUF_RESET); /* shoudn't be needed */
136 hv_delete_ent(MY_CXT.ob_reg, ob_id, 0, 0);
141 /* Create a trigger for an object. The trigger is a magical SV
142 * that holds a weak ref to the object. The magic fires when the object
143 * expires and takes care of garbage collection in registred hashes.
144 * For that purpose, the magic structure holds the original id of
145 * the object, and a list (a hash, really) of hashes from which the
146 * object may * have to be deleted. The trigger is stored in the
147 * object registry and is also deleted when the object expires.
149 SV* HUF_new_trigger(SV* obj, SV* ob_id) {
151 SV* trigger = sv_rvweaken(newRV_inc(SvRV(obj)));
153 sv_2mortal((SV*)cont);
154 av_store(cont, 0, SvREFCNT_inc(ob_id));
155 av_store(cont, 1, (SV*)newHV());
156 HUF_add_uvar_magic(trigger, NULL, &HUF_destroy_obj, 0, (SV*)cont);
157 hv_store_ent(MY_CXT.ob_reg, ob_id, trigger, 0);
161 /* retrieve a trigger for obj if one exists, return NULL otherwise */
162 SV* HUF_ask_trigger(SV* ob_id) {
165 if (ent = hv_fetch_ent(MY_CXT.ob_reg, ob_id, 0, 0))
170 /* get the trigger for an object, creating it if necessary */
171 SV* HUF_get_trigger0(SV* obj, SV* ob_id) {
173 if (!(trigger = HUF_ask_trigger(ob_id)))
174 trigger = HUF_new_trigger(obj, ob_id);
178 SV* HUF_get_trigger(SV* obj, SV* ob_id) {
179 SV* trigger = HUF_ask_trigger(ob_id);
181 trigger = HUF_new_trigger(obj, ob_id);
185 /* mark an object (trigger) as having been used with a field
188 void HUF_mark_field(SV* trigger, SV* field) {
189 AV* cont = HUF_get_trigger_content(trigger);
190 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
191 SV* field_ref = newRV_inc(field);
192 UV field_addr = PTR2UV(field);
193 hv_store(field_tab, (char *)&field_addr, sizeof(field_addr), field_ref, 0);
196 /* Determine, from the value of action, whether this call may create a new
198 #define HUF_WOULD_CREATE_KEY(x) ((x) != HV_DELETE && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
200 /* The key exchange functions. They communicate with S_hv_magic_uvar_xkey
202 I32 HUF_watch_key_safe(pTHX_ IV action, SV* field) {
203 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
205 if (mg && (keysv = mg->mg_obj)) {
206 if (SvROK(keysv)) { /* ref key */
207 SV* ob_id = HUF_obj_id(keysv);
208 mg->mg_obj = ob_id; /* key replacement */
209 if (HUF_WOULD_CREATE_KEY(action)) {
210 SV* trigger = HUF_get_trigger(keysv, ob_id);
211 HUF_mark_field(trigger, field);
213 } else if (HUF_WOULD_CREATE_KEY(action)) { /* string key */
214 /* registered as object id? */
216 if ( trigger = HUF_ask_trigger(keysv))
217 HUF_mark_field( trigger, field);
220 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_safe'");
225 I32 HUF_watch_key_id(pTHX_ IV action, SV* field) {
226 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
228 if (mg && (keysv = mg->mg_obj)) {
229 if (SvROK(keysv)) /* ref key */
230 mg->mg_obj = HUF_obj_id(keysv); /* key replacement */
232 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_id'");
237 int HUF_func_2mode( I32(* val)(pTHX_ IV, SV*)) {
239 if (val == &HUF_watch_key_id)
241 if (val == &HUF_watch_key_safe)
246 I32(* HUF_mode_2func( int mode))(pTHX_ IV, SV*) {
247 I32(* ans)(pTHX_ IV, SV*) = NULL;
250 ans = &HUF_watch_key_id;
253 ans = &HUF_watch_key_safe;
259 /* see if something is a field hash */
260 int HUF_get_status(HV* hash) {
262 if (hash && (SvTYPE(hash) == SVt_PVHV)) {
265 if ((mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
266 (uf = (struct ufuncs *)mg->mg_ptr) &&
269 ans = HUF_func_2mode(uf->uf_val);
275 /* Thread support. These routines are called by CLONE (and nothing else) */
277 /* Fix entries for one object in all field hashes */
278 void HUF_fix_trigger(SV* trigger, SV* new_id) {
279 AV* cont = HUF_get_trigger_content(trigger);
280 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
281 HV* new_tab = newHV();
283 SV* old_id = *av_fetch(cont, 0, 0);
284 hv_iterinit(field_tab);
285 while (ent = hv_iternext(field_tab)) {
286 SV* field_ref = HeVAL(ent);
287 HV* field = (HV*)SvRV(field_ref);
288 UV field_addr = PTR2UV(field);
290 /* recreate field tab entry */
291 hv_store(new_tab, (char *)&field_addr, sizeof(field_addr), SvREFCNT_inc(field_ref), 0);
292 /* recreate field entry, if any */
293 if (val = hv_delete_ent(field, old_id, 0, 0))
294 hv_store_ent(field, new_id, SvREFCNT_inc(val), 0);
296 /* update the trigger */
297 av_store(cont, 0, SvREFCNT_inc(new_id));
298 av_store(cont, 1, (SV*)new_tab);
301 /* Go over object registry and fix all objects. Also fix the object
304 void HUF_fix_objects(void) {
308 AV* oblist = (AV*)sv_2mortal((SV*)newAV());
309 hv_iterinit(MY_CXT.ob_reg);
310 while(ent = hv_iternext(MY_CXT.ob_reg))
311 av_push(oblist, SvREFCNT_inc(hv_iterkeysv(ent)));
312 len = av_len(oblist);
313 for (i = 0; i <= len; ++i) {
314 SV* old_id = *av_fetch(oblist, i, 0);
315 SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0);
316 SV* obj = SvRV(trigger);
319 SV* new_id = HUF_OBJ_ID(obj);
321 /* Replace cached object ID with this new one */
322 for (mg = SvMAGIC(obj); mg; mg = mg->mg_moremagic) {
323 if ((mg->mg_type == PERL_MAGIC_ext) &&
324 (mg->mg_private == HUF_IDCACHE)
330 HUF_fix_trigger(trigger, new_id);
331 hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0);
335 /* test support (not needed for functionality) */
338 I32 HUF_inc_var(pTHX_ IV index, SV* which) {
339 sv_setiv(counter, 1 + SvIV(counter));
343 MODULE = Hash::Util::FieldHash PACKAGE = Hash::Util::FieldHash
347 HUF_global(HUF_INIT); /* create variables */
351 _fieldhash(SV* href, int mode)
357 href && SvROK(href) &&
358 (field = (HV*)SvRV(href)) &&
359 SvTYPE(field) == SVt_PVHV
364 HUF_mode_2func( mode),
369 RETVAL = HUF_get_status(field);
379 XPUSHs(HUF_obj_id(ref));
388 SV* obj = HUF_ask_trigger(id);
390 RETVAL = newRV_inc(SvRV(obj));
392 RETVAL = &PL_sv_undef;
398 register(SV* obj, ...)
405 Perl_die(aTHX_ "Attempt to register a non-ref");
407 RETVAL = newRV_inc(SvRV(obj));
409 trigger = HUF_get_trigger(obj, HUF_obj_id(obj));
410 for (i = 1; i < items; ++ i) {
411 SV* field_ref = POPs;
412 if (SvROK(field_ref) && (SvTYPE(SvRV(field_ref)) == SVt_PVHV)) {
413 HUF_mark_field(trigger, SvRV(field_ref));
420 CLONE(char* classname)
422 if (0 == strcmp(classname, "Hash::Util::FieldHash")) {
423 HUF_global(HUF_CLONE);
428 _active_fields(SV* obj)
431 SV* ob_id = HUF_obj_id(obj);
432 SV* trigger = HUF_ask_trigger(ob_id);
434 AV* cont = HUF_get_trigger_content(trigger);
435 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
437 hv_iterinit(field_tab);
438 while (ent = hv_iternext(field_tab)) {
439 HV* field = (HV*)SvRV(HeVAL(ent));
440 if (hv_exists_ent(field, ob_id, 0))
441 XPUSHs(sv_2mortal(newRV_inc((SV*)field)));
447 _test_uvar_get(SV* svref, SV* countref)
449 if (SvROK(svref) && SvROK(countref)) {
450 counter = SvRV(countref);
451 sv_setiv(counter, 0);
462 _test_uvar_set(SV* svref, SV* countref)
464 if (SvROK(svref) && SvROK(countref)) {
465 counter = SvRV(countref);
466 sv_setiv(counter, 0);
467 counter = SvRV(countref);
478 _test_uvar_same(SV* svref, SV* countref)
480 if (SvROK(svref) && SvROK(countref)) {
481 counter = SvRV(countref);
482 sv_setiv(counter, 0);