5 /* support for Hash::Util::FieldHash, prefix HUF_ */
7 /* The object registry, a package variable */
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
14 /* For global cache of object registry */
15 #define MY_CXT_KEY "Hash::Util::FieldHash::_guts" XS_VERSION
17 HV* ob_reg; /* Cache object registry */
21 /* Deal with global context */
26 void HUF_global(I32 how) {
27 if (how == HUF_INIT) {
29 MY_CXT.ob_reg = get_hv(HUF_OB_REG, 1);
30 } else if (how == HUF_CLONE) {
32 MY_CXT.ob_reg = get_hv(HUF_OB_REG, 0);
33 } else if (how == HUF_RESET) {
35 MY_CXT.ob_reg = get_hv(HUF_OB_REG, 0);
39 /* the id as an SV, optionally marked in the nv (unused feature) */
40 SV* HUF_id(SV* ref, NV cookie) {
41 SV* id = sv_newmortal();
43 SvUPGRADE(id, SVt_PVIV);
45 SvUPGRADE(id, SVt_PVNV);
49 SvIV_set(id, PTR2UV(SvRV(ref)));
54 /* plain id, only used for field hash entries in field lists */
55 SV* HUF_field_id(SV* obj) {
56 return HUF_id(obj, 0.0);
59 /* object id (may be different in future) */
60 SV* HUF_obj_id(SV* obj) {
61 return HUF_id(obj, 0.0);
64 /* set up uvar magic for any sv */
65 void HUF_add_uvar_magic(
66 SV* sv, /* the sv to enchant, visible to * get/set */
67 I32(* val)(pTHX_ IV, SV*), /* "get" function */
68 I32(* set)(pTHX_ IV, SV*), /* "set" function */
69 I32 index, /* get/set will see this */
70 SV* thing /* any associated info */
76 sv_magic(sv, thing, PERL_MAGIC_uvar, (char*)&uf, sizeof(uf));
79 /* Fetch the data container of a trigger */
80 AV* HUF_get_trigger_content(SV* trigger) {
82 if (trigger && (mg = mg_find(trigger, PERL_MAGIC_uvar)))
83 return (AV*)mg->mg_obj;
87 /* Delete an object from all field hashes it may occur in. Also delete
88 * the object's entry from the object registry. This function goes in
89 * the uf_set field of the uvar magic of a trigger.
91 I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) {
92 /* Do nothing if the weakref wasn't undef'd. Also don't bother
93 * during global destruction. (MY_CXT.ob_reg is sometimes funny there) */
94 if (!SvROK(trigger) && (!PL_in_clean_all)) {
96 AV* cont = HUF_get_trigger_content(trigger);
97 SV* ob_id = *av_fetch(cont, 0, 0);
98 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
100 hv_iterinit(field_tab);
101 while (ent = hv_iternext(field_tab)) {
102 SV* field_ref = HeVAL(ent);
103 SV* field = SvRV(field_ref);
104 hv_delete_ent((HV*)field, ob_id, G_DISCARD, 0);
106 /* make it safe in case we must run in global clenaup, after all */
108 HUF_global(HUF_RESET);
109 hv_delete_ent(MY_CXT.ob_reg, ob_id, G_DISCARD, 0);
114 /* Create a trigger for an object. The trigger is a magical weak ref
115 * that fires when the weak ref expires. it holds the original id of
116 * the object, and a list of field hashes from which the object may
117 * have to be deleted. The trigger is stored in the object registry
118 * and also deleted when the object expires.
120 SV* HUF_new_trigger(SV* obj, SV* ob_id) {
122 SV* trigger = sv_rvweaken(newRV_inc(SvRV(obj)));
124 sv_2mortal((SV*)cont);
125 av_store(cont, 0, SvREFCNT_inc(ob_id));
126 av_store(cont, 1, (SV*)newHV());
127 HUF_add_uvar_magic(trigger, NULL, &HUF_destroy_obj, 0, (SV*)cont);
128 hv_store_ent(MY_CXT.ob_reg, ob_id, trigger, 0);
132 /* retrieve a trigger for obj if one exists, return NULL otherwise */
133 SV* HUF_ask_trigger(SV* ob_id) {
136 if (ent = hv_fetch_ent(MY_CXT.ob_reg, ob_id, 0, 0))
141 /* get the trigger for an object, creating it if necessary */
142 SV* HUF_get_trigger(SV* obj, SV* ob_id) {
144 if (!(trigger = HUF_ask_trigger(ob_id)))
145 trigger = HUF_new_trigger(obj, ob_id);
149 /* mark an object (trigger) as having been used with a field */
150 void HUF_mark_field(SV* trigger, SV* field) {
151 AV* cont = HUF_get_trigger_content(trigger);
152 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
153 SV* field_ref = newRV_inc(field);
154 SV* field_id = HUF_field_id(field_ref);
155 hv_store_ent(field_tab, field_id, field_ref, 0);
158 #define HV_FETCH_ISSTORE 0x01
159 #define HV_FETCH_ISEXISTS 0x02
160 #define HV_FETCH_LVALUE 0x04
161 #define HV_FETCH_JUST_SV 0x08
163 #define HUF_WOULD_CREATE_KEY(x) ((x) != -1 && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE)))
165 /* The key exchange function. It communicates with S_hv_magic_uvar_xkey
167 I32 HUF_watch_key(pTHX_ IV action, SV* field) {
168 MAGIC* mg = mg_find(field, PERL_MAGIC_uvar);
169 SV* keysv = mg->mg_obj;
170 if (keysv && SvROK(keysv)) {
171 SV* ob_id = HUF_obj_id(keysv);
172 mg->mg_obj = ob_id; /* key replacement */
173 if (HUF_WOULD_CREATE_KEY(action)) {
174 SV* trigger = HUF_get_trigger(keysv, ob_id);
175 HUF_mark_field(trigger, field);
181 /* see if something is a field hash */
182 int HUF_get_status(HV* hash) {
184 if (hash && (SvTYPE(hash) == SVt_PVHV)) {
187 ans = (mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) &&
188 (uf = (struct ufuncs *)mg->mg_ptr) &&
189 (uf->uf_val == &HUF_watch_key) &&
190 (uf->uf_set == NULL);
195 /* Thread support. These routines are called by CLONE (and nothing else) */
197 /* Fix entries for one object in all field hashes */
198 void HUF_fix_trigger(SV* trigger, SV* new_id) {
199 AV* cont = HUF_get_trigger_content(trigger);
200 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
201 HV* new_tab = newHV();
203 SV* old_id = *av_fetch(cont, 0, 0);
204 hv_iterinit(field_tab);
205 while (ent = hv_iternext(field_tab)) {
206 SV* field_ref = HeVAL(ent);
207 SV* field_id = HUF_field_id(field_ref);
208 HV* field = (HV*)SvRV(field_ref);
210 /* recreate field tab entry */
211 hv_store_ent(new_tab, field_id, SvREFCNT_inc(field_ref), 0);
212 /* recreate field entry, if any */
213 if (val = hv_delete_ent(field, old_id, 0, 0))
214 hv_store_ent(field, new_id, SvREFCNT_inc(val), 0);
216 /* update the trigger */
217 av_store(cont, 0, SvREFCNT_inc(new_id));
218 av_store(cont, 1, (SV*)new_tab);
221 /* Go over object registry and fix all objects. Also fix the object
224 void HUF_fix_objects(void) {
228 AV* oblist = (AV*)sv_2mortal((SV*)newAV());
229 hv_iterinit(MY_CXT.ob_reg);
230 while(ent = hv_iternext(MY_CXT.ob_reg))
231 av_push(oblist, SvREFCNT_inc(hv_iterkeysv(ent)));
232 len = av_len(oblist);
233 for (i = 0; i <= len; ++i) {
234 SV* old_id = *av_fetch(oblist, i, 0);
235 SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0);
236 SV* new_id = HUF_obj_id(trigger);
237 HUF_fix_trigger(trigger, new_id);
238 hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0);
242 /* test support (not needed for functionality) */
245 I32 HUF_inc_var(pTHX_ IV index, SV* which) {
246 sv_setiv(counter, 1 + SvIV(counter));
250 MODULE = Hash::Util::FieldHash PACKAGE = Hash::Util::FieldHash
254 HUF_global(HUF_INIT); /* create variables */
258 _fieldhash(SV* href, int mode)
264 href && SvROK(href) &&
265 (field = (HV*)SvRV(href)) &&
266 SvTYPE(field) == SVt_PVHV
275 RETVAL = HUF_get_status(field);
283 if (0 == strcmp(class, "Hash::Util::FieldHash")) {
284 HUF_global(HUF_CLONE);
293 RETVAL = HUF_obj_id(obj);
298 _active_fields(SV* obj)
301 SV* ob_id = HUF_obj_id(obj);
302 SV* trigger = HUF_ask_trigger(ob_id);
304 AV* cont = HUF_get_trigger_content(trigger);
305 HV* field_tab = (HV*) *av_fetch(cont, 1, 0);
307 hv_iterinit(field_tab);
308 while (ent = hv_iternext(field_tab)) {
309 HV* field = (HV*)SvRV(HeVAL(ent));
310 if (hv_exists_ent(field, ob_id, 0))
311 XPUSHs(sv_2mortal(newRV_inc((SV*)field)));
317 _test_uvar_get(SV* svref, SV* countref)
319 if (SvROK(svref) && SvROK(countref)) {
320 counter = SvRV(countref);
321 sv_setiv(counter, 0);
332 _test_uvar_set(SV* svref, SV* countref)
334 if (SvROK(svref) && SvROK(countref)) {
335 counter = SvRV(countref);
336 sv_setiv(counter, 0);
337 counter = SvRV(countref);
348 _test_uvar_same(SV* svref, SV* countref)
350 if (SvROK(svref) && SvROK(countref)) {
351 counter = SvRV(countref);
352 sv_setiv(counter, 0);