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;
86 /* Return the object ID */
90 /* set up uvar magic for any sv */
91 void HUF_add_uvar_magic(
92 SV* sv, /* the sv to enchant, visible to get/set */
93 I32(* val)(pTHX_ IV, SV*), /* "get" function */
94 I32(* set)(pTHX_ IV, SV*), /* "set" function */
95 I32 index, /* get/set will see this */
96 SV* thing /* any associated info */
102 sv_magic(sv, thing, PERL_MAGIC_uvar, (char*)&uf, sizeof(uf));
105 /* Fetch the data container of a trigger */
106 AV* HUF_get_trigger_content(SV* trigger) {
108 if (trigger && (mg = mg_find(trigger, PERL_MAGIC_uvar)))
109 return (AV*)mg->mg_obj;
113 /* Delete an object from all field hashes it may occur in. Also delete
114 * the object's entry from the object registry. This function goes in
115 * the uf_set field of the uvar magic of a trigger.
117 I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
118 /* Do nothing if the weakref wasn't undef'd. Also don't bother
119 * during global destruction. (MY_CXT.ob_reg is sometimes funny there) */
120 if (!SvROK(trigger) && (!PL_in_clean_all)) {
122 AV* cont = HUF_get_trigger_content(trigger);
123 SV* ob_id = *av_fetch(cont, 0, 0);
124 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
126 hv_iterinit(field_tab);
127 while (ent = hv_iternext(field_tab)) {
128 SV* field_ref = HeVAL(ent);
129 SV* field = SvRV(field_ref);
130 hv_delete_ent((HV*)field, ob_id, 0, 0);
132 /* make it safe in case we must run in global clenaup, after all */
134 HUF_global(HUF_RESET); /* shoudn't be needed */
135 hv_delete_ent(MY_CXT.ob_reg, ob_id, 0, 0);
140 /* Create a trigger for an object. The trigger is a magical SV
141 * that holds a weak ref to the object. The magic fires when the object
142 * expires and takes care of garbage collection in registred hashes.
143 * For that purpose, the magic structure holds the original id of
144 * the object, and a list (a hash, really) of hashes from which the
145 * object may * have to be deleted. The trigger is stored in the
146 * object registry and is also deleted when the object expires.
148 SV* HUF_new_trigger(SV* obj, SV* ob_id) {
150 SV* trigger = sv_rvweaken(newRV_inc(SvRV(obj)));
152 sv_2mortal((SV*)cont);
153 av_store(cont, 0, SvREFCNT_inc(ob_id));
154 av_store(cont, 1, (SV*)newHV());
155 HUF_add_uvar_magic(trigger, NULL, &HUF_destroy_obj, 0, (SV*)cont);
156 hv_store_ent(MY_CXT.ob_reg, ob_id, trigger, 0);
160 /* retrieve a trigger for obj if one exists, return NULL otherwise */
161 SV* HUF_ask_trigger(SV* ob_id) {
164 if (ent = hv_fetch_ent(MY_CXT.ob_reg, ob_id, 0, 0))
169 /* get the trigger for an object, creating it if necessary */
170 SV* HUF_get_trigger0(SV* obj, SV* ob_id) {
172 if (!(trigger = HUF_ask_trigger(ob_id)))
173 trigger = HUF_new_trigger(obj, ob_id);
177 SV* HUF_get_trigger(SV* obj, SV* ob_id) {
178 SV* trigger = HUF_ask_trigger(ob_id);
180 trigger = HUF_new_trigger(obj, ob_id);
184 /* mark an object (trigger) as having been used with a field
187 void HUF_mark_field(SV* trigger, SV* field) {
188 AV* cont = HUF_get_trigger_content(trigger);
189 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
190 SV* field_ref = newRV_inc(field);
191 UV field_addr = PTR2UV(field);
192 hv_store(field_tab, (char *)&field_addr, sizeof(field_addr), field_ref, 0);
195 /* Determine, from the value of action, whether this call may create a new
197 #define HUF_WOULD_CREATE_KEY(x) ((x) != HV_DELETE && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
199 /* The key exchange functions. They communicate with S_hv_magic_uvar_xkey
201 I32 HUF_watch_key_safe(pTHX_ IV action, SV* field) {
202 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
204 if (mg && (keysv = mg->mg_obj)) {
205 if (SvROK(keysv)) { /* ref key */
206 SV* ob_id = HUF_obj_id(keysv);
207 mg->mg_obj = ob_id; /* key replacement */
208 if (HUF_WOULD_CREATE_KEY(action)) {
209 SV* trigger = HUF_get_trigger(keysv, ob_id);
210 HUF_mark_field(trigger, field);
212 } else if (HUF_WOULD_CREATE_KEY(action)) { /* string key */
213 /* registered as object id? */
215 if ( trigger = HUF_ask_trigger(keysv))
216 HUF_mark_field( trigger, field);
219 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_safe'");
224 I32 HUF_watch_key_id(pTHX_ IV action, SV* field) {
225 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
227 if (mg && (keysv = mg->mg_obj)) {
228 if (SvROK(keysv)) /* ref key */
229 mg->mg_obj = HUF_obj_id(keysv); /* key replacement */
231 Perl_die(aTHX_ "Rogue call of 'HUF_watch_key_id'");
236 int HUF_func_2mode( I32(* val)(pTHX_ IV, SV*)) {
238 if (val == &HUF_watch_key_id)
240 if (val == &HUF_watch_key_safe)
245 I32(* HUF_mode_2func( int mode))(pTHX_ IV, SV*) {
246 I32(* ans)(pTHX_ IV, SV*) = NULL;
249 ans = &HUF_watch_key_id;
252 ans = &HUF_watch_key_safe;
258 /* see if something is a field hash */
259 int HUF_get_status(HV* hash) {
261 if (hash && (SvTYPE(hash) == SVt_PVHV)) {
264 if ((mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
265 (uf = (struct ufuncs *)mg->mg_ptr) &&
268 ans = HUF_func_2mode(uf->uf_val);
274 /* Thread support. These routines are called by CLONE (and nothing else) */
276 /* Fix entries for one object in all field hashes */
277 void HUF_fix_trigger(SV* trigger, SV* new_id) {
278 AV* cont = HUF_get_trigger_content(trigger);
279 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
280 HV* new_tab = newHV();
282 SV* old_id = *av_fetch(cont, 0, 0);
283 hv_iterinit(field_tab);
284 while (ent = hv_iternext(field_tab)) {
285 SV* field_ref = HeVAL(ent);
286 HV* field = (HV*)SvRV(field_ref);
287 UV field_addr = PTR2UV(field);
289 /* recreate field tab entry */
290 hv_store(new_tab, (char *)&field_addr, sizeof(field_addr), SvREFCNT_inc(field_ref), 0);
291 /* recreate field entry, if any */
292 if (val = hv_delete_ent(field, old_id, 0, 0))
293 hv_store_ent(field, new_id, SvREFCNT_inc(val), 0);
295 /* update the trigger */
296 av_store(cont, 0, SvREFCNT_inc(new_id));
297 av_store(cont, 1, (SV*)new_tab);
300 /* Go over object registry and fix all objects. Also fix the object
303 void HUF_fix_objects(void) {
307 AV* oblist = (AV*)sv_2mortal((SV*)newAV());
308 hv_iterinit(MY_CXT.ob_reg);
309 while(ent = hv_iternext(MY_CXT.ob_reg))
310 av_push(oblist, SvREFCNT_inc(hv_iterkeysv(ent)));
311 len = av_len(oblist);
312 for (i = 0; i <= len; ++i) {
313 SV* old_id = *av_fetch(oblist, i, 0);
314 SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0);
315 SV* obj = SvRV(trigger);
318 SV* new_id = HUF_OBJ_ID(obj);
320 /* Replace cached object ID with this new one */
321 for (mg = SvMAGIC(obj); mg; mg = mg->mg_moremagic) {
322 if ((mg->mg_type == PERL_MAGIC_ext) &&
323 (mg->mg_private == HUF_IDCACHE)
329 HUF_fix_trigger(trigger, new_id);
330 hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0);
334 /* test support (not needed for functionality) */
337 I32 HUF_inc_var(pTHX_ IV index, SV* which) {
338 sv_setiv(counter, 1 + SvIV(counter));
342 MODULE = Hash::Util::FieldHash PACKAGE = Hash::Util::FieldHash
346 HUF_global(HUF_INIT); /* create variables */
350 _fieldhash(SV* href, int mode)
356 href && SvROK(href) &&
357 (field = (HV*)SvRV(href)) &&
358 SvTYPE(field) == SVt_PVHV
363 HUF_mode_2func( mode),
368 RETVAL = HUF_get_status(field);
378 XPUSHs(HUF_obj_id(ref));
387 SV* obj = HUF_ask_trigger(id);
389 RETVAL = newRV_inc(SvRV(obj));
391 RETVAL = &PL_sv_undef;
397 register(SV* obj, ...)
404 Perl_die(aTHX_ "Attempt to register a non-ref");
406 RETVAL = newRV_inc(SvRV(obj));
408 trigger = HUF_get_trigger(obj, HUF_obj_id(obj));
409 for (i = 1; i < items; ++ i) {
410 SV* field_ref = POPs;
411 if (SvROK(field_ref) && (SvTYPE(SvRV(field_ref)) == SVt_PVHV)) {
412 HUF_mark_field(trigger, SvRV(field_ref));
419 CLONE(char* classname)
421 if (0 == strcmp(classname, "Hash::Util::FieldHash")) {
422 HUF_global(HUF_CLONE);
427 _active_fields(SV* obj)
430 SV* ob_id = HUF_obj_id(obj);
431 SV* trigger = HUF_ask_trigger(ob_id);
433 AV* cont = HUF_get_trigger_content(trigger);
434 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
436 hv_iterinit(field_tab);
437 while (ent = hv_iternext(field_tab)) {
438 HV* field = (HV*)SvRV(HeVAL(ent));
439 if (hv_exists_ent(field, ob_id, 0))
440 XPUSHs(sv_2mortal(newRV_inc((SV*)field)));
446 _test_uvar_get(SV* svref, SV* countref)
448 if (SvROK(svref) && SvROK(countref)) {
449 counter = SvRV(countref);
450 sv_setiv(counter, 0);
461 _test_uvar_set(SV* svref, SV* countref)
463 if (SvROK(svref) && SvROK(countref)) {
464 counter = SvRV(countref);
465 sv_setiv(counter, 0);
466 counter = SvRV(countref);
477 _test_uvar_same(SV* svref, SV* countref)
479 if (SvROK(svref) && SvROK(countref)) {
480 counter = SvRV(countref);
481 sv_setiv(counter, 0);