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1 | #include "EXTERN.h" |
2 | #include "perl.h" |
3 | #include "XSUB.h" |
4 | |
5 | /* support for Hash::Util::FieldHash, prefix HUF_ */ |
6 | |
6ff38c27 |
7 | /* A Perl sub that returns a hashref to the object registry */ |
8 | #define HUF_OB_REG "Hash::Util::FieldHash::_ob_reg" |
1e73acc8 |
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 | |
1e73acc8 |
13 | /* For global cache of object registry */ |
14 | #define MY_CXT_KEY "Hash::Util::FieldHash::_guts" XS_VERSION |
15 | typedef struct { |
16 | HV* ob_reg; /* Cache object registry */ |
17 | } my_cxt_t; |
18 | START_MY_CXT |
19 | |
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20 | /* Inquire the object registry (a lexical hash) from perl */ |
21 | HV* HUF_get_ob_reg(void) { |
22 | dSP; |
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23 | HV* ob_reg = NULL; |
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24 | I32 items; |
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25 | ENTER; |
26 | SAVETMPS; |
27 | |
28 | PUSHMARK(SP); |
0dbc1c87 |
29 | items = call_pv(HUF_OB_REG, G_SCALAR|G_NOARGS); |
6ff38c27 |
30 | SPAGAIN; |
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31 | |
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32 | if (items == 1 && TOPs && SvROK(TOPs) && SvTYPE(SvRV(TOPs)) == SVt_PVHV) |
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33 | ob_reg = (HV*)SvRV(POPs); |
91dba0be |
34 | PUTBACK; |
35 | FREETMPS; |
36 | LEAVE; |
37 | |
45552c86 |
38 | if (!ob_reg) |
39 | Perl_die(aTHX_ "Can't get object registry hash"); |
40 | return ob_reg; |
6ff38c27 |
41 | } |
42 | |
1e73acc8 |
43 | /* Deal with global context */ |
44 | #define HUF_INIT 1 |
45 | #define HUF_CLONE 0 |
46 | #define HUF_RESET -1 |
47 | |
48 | void HUF_global(I32 how) { |
49 | if (how == HUF_INIT) { |
50 | MY_CXT_INIT; |
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51 | MY_CXT.ob_reg = HUF_get_ob_reg(); |
1e73acc8 |
52 | } else if (how == HUF_CLONE) { |
53 | MY_CXT_CLONE; |
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54 | MY_CXT.ob_reg = HUF_get_ob_reg(); |
1e73acc8 |
55 | } else if (how == HUF_RESET) { |
56 | dMY_CXT; |
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57 | MY_CXT.ob_reg = HUF_get_ob_reg(); |
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58 | } |
59 | } |
60 | |
61 | /* the id as an SV, optionally marked in the nv (unused feature) */ |
62 | SV* HUF_id(SV* ref, NV cookie) { |
63 | SV* id = sv_newmortal(); |
64 | if (cookie == 0 ) { |
65 | SvUPGRADE(id, SVt_PVIV); |
66 | } else { |
67 | SvUPGRADE(id, SVt_PVNV); |
68 | SvNV_set(id, cookie); |
69 | SvNOK_on(id); |
70 | } |
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71 | SvIV_set(id, PTR2UV(SvRV(ref))); |
1e73acc8 |
72 | SvIOK_on(id); |
73 | return id; |
74 | } |
75 | |
76 | /* plain id, only used for field hash entries in field lists */ |
77 | SV* HUF_field_id(SV* obj) { |
78 | return HUF_id(obj, 0.0); |
79 | } |
80 | |
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81 | /* object id (same as plain, may be different in future) */ |
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82 | SV* HUF_obj_id(SV* obj) { |
83 | return HUF_id(obj, 0.0); |
84 | } |
85 | |
86 | /* set up uvar magic for any sv */ |
87 | void HUF_add_uvar_magic( |
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88 | SV* sv, /* the sv to enchant, visible to get/set */ |
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89 | I32(* val)(pTHX_ IV, SV*), /* "get" function */ |
90 | I32(* set)(pTHX_ IV, SV*), /* "set" function */ |
91 | I32 index, /* get/set will see this */ |
92 | SV* thing /* any associated info */ |
93 | ) { |
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94 | struct ufuncs uf; |
95 | uf.uf_val = val; |
96 | uf.uf_set = set; |
97 | uf.uf_index = index; |
98 | sv_magic(sv, thing, PERL_MAGIC_uvar, (char*)&uf, sizeof(uf)); |
99 | } |
100 | |
101 | /* Fetch the data container of a trigger */ |
102 | AV* HUF_get_trigger_content(SV* trigger) { |
103 | MAGIC* mg; |
104 | if (trigger && (mg = mg_find(trigger, PERL_MAGIC_uvar))) |
105 | return (AV*)mg->mg_obj; |
106 | return NULL; |
107 | } |
108 | |
109 | /* Delete an object from all field hashes it may occur in. Also delete |
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110 | * the object's entry from the object registry. This function goes in |
111 | * the uf_set field of the uvar magic of a trigger. |
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112 | */ |
113 | I32 HUF_destroy_obj(pTHX_ IV index, SV* trigger) { |
114 | /* Do nothing if the weakref wasn't undef'd. Also don't bother |
115 | * during global destruction. (MY_CXT.ob_reg is sometimes funny there) */ |
116 | if (!SvROK(trigger) && (!PL_in_clean_all)) { |
117 | dMY_CXT; |
118 | AV* cont = HUF_get_trigger_content(trigger); |
119 | SV* ob_id = *av_fetch(cont, 0, 0); |
120 | HV* field_tab = (HV*) *av_fetch(cont, 1, 0); |
121 | HE* ent; |
122 | hv_iterinit(field_tab); |
123 | while (ent = hv_iternext(field_tab)) { |
124 | SV* field_ref = HeVAL(ent); |
125 | SV* field = SvRV(field_ref); |
126 | hv_delete_ent((HV*)field, ob_id, G_DISCARD, 0); |
127 | } |
128 | /* make it safe in case we must run in global clenaup, after all */ |
129 | if (PL_in_clean_all) |
130 | HUF_global(HUF_RESET); |
131 | hv_delete_ent(MY_CXT.ob_reg, ob_id, G_DISCARD, 0); |
132 | } |
133 | return 0; |
134 | } |
135 | |
136 | /* Create a trigger for an object. The trigger is a magical weak ref |
137 | * that fires when the weak ref expires. it holds the original id of |
138 | * the object, and a list of field hashes from which the object may |
139 | * have to be deleted. The trigger is stored in the object registry |
140 | * and also deleted when the object expires. |
141 | */ |
142 | SV* HUF_new_trigger(SV* obj, SV* ob_id) { |
143 | dMY_CXT; |
144 | SV* trigger = sv_rvweaken(newRV_inc(SvRV(obj))); |
145 | AV* cont = newAV(); |
146 | sv_2mortal((SV*)cont); |
147 | av_store(cont, 0, SvREFCNT_inc(ob_id)); |
148 | av_store(cont, 1, (SV*)newHV()); |
149 | HUF_add_uvar_magic(trigger, NULL, &HUF_destroy_obj, 0, (SV*)cont); |
150 | hv_store_ent(MY_CXT.ob_reg, ob_id, trigger, 0); |
151 | return trigger; |
152 | } |
153 | |
154 | /* retrieve a trigger for obj if one exists, return NULL otherwise */ |
155 | SV* HUF_ask_trigger(SV* ob_id) { |
156 | dMY_CXT; |
157 | HE* ent; |
158 | if (ent = hv_fetch_ent(MY_CXT.ob_reg, ob_id, 0, 0)) |
159 | return HeVAL(ent); |
160 | return NULL; |
161 | } |
162 | |
163 | /* get the trigger for an object, creating it if necessary */ |
164 | SV* HUF_get_trigger(SV* obj, SV* ob_id) { |
165 | SV* trigger; |
166 | if (!(trigger = HUF_ask_trigger(ob_id))) |
167 | trigger = HUF_new_trigger(obj, ob_id); |
168 | return trigger; |
169 | } |
170 | |
171 | /* mark an object (trigger) as having been used with a field */ |
172 | void HUF_mark_field(SV* trigger, SV* field) { |
173 | AV* cont = HUF_get_trigger_content(trigger); |
174 | HV* field_tab = (HV*) *av_fetch(cont, 1, 0); |
175 | SV* field_ref = newRV_inc(field); |
176 | SV* field_id = HUF_field_id(field_ref); |
177 | hv_store_ent(field_tab, field_id, field_ref, 0); |
178 | } |
179 | |
6ff38c27 |
180 | /* These constants are not in the API. If they ever change in hv.c this code |
181 | * must be updated */ |
a607227a |
182 | #define HV_FETCH_ISSTORE 0x01 |
183 | #define HV_FETCH_ISEXISTS 0x02 |
184 | #define HV_FETCH_LVALUE 0x04 |
185 | #define HV_FETCH_JUST_SV 0x08 |
186 | |
187 | #define HUF_WOULD_CREATE_KEY(x) ((x) != -1 && ((x) & (HV_FETCH_ISSTORE | HV_FETCH_LVALUE))) |
188 | |
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189 | /* The key exchange function. It communicates with S_hv_magic_uvar_xkey |
190 | * in hv.c */ |
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191 | I32 HUF_watch_key(pTHX_ IV action, SV* field) { |
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192 | MAGIC* mg = mg_find(field, PERL_MAGIC_uvar); |
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193 | SV* keysv; |
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194 | if (mg) { |
195 | keysv = mg->mg_obj; |
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196 | if (keysv && !SvROK(keysv)) { /* is string an object-id? */ |
197 | SV* obj = HUF_ask_trigger(keysv); |
198 | if (obj) |
199 | keysv = obj; /* use the object instead, so registry happens */ |
200 | } |
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201 | if (keysv && SvROK(keysv)) { |
202 | SV* ob_id = HUF_obj_id(keysv); |
203 | mg->mg_obj = ob_id; /* key replacement */ |
204 | if (HUF_WOULD_CREATE_KEY(action)) { |
205 | SV* trigger = HUF_get_trigger(keysv, ob_id); |
206 | HUF_mark_field(trigger, field); |
207 | } |
a607227a |
208 | } |
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209 | } else { |
210 | Perl_die(aTHX_ "Rogue call of 'HUF_watch_key'"); |
1e73acc8 |
211 | } |
212 | return 0; |
213 | } |
214 | |
215 | /* see if something is a field hash */ |
216 | int HUF_get_status(HV* hash) { |
217 | int ans = 0; |
218 | if (hash && (SvTYPE(hash) == SVt_PVHV)) { |
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219 | MAGIC* mg; |
220 | struct ufuncs* uf; |
221 | ans = (mg = mg_find((SV*)hash, PERL_MAGIC_uvar)) && |
222 | (uf = (struct ufuncs *)mg->mg_ptr) && |
223 | (uf->uf_val == &HUF_watch_key) && |
224 | (uf->uf_set == NULL); |
225 | } |
226 | return ans; |
227 | } |
228 | |
229 | /* Thread support. These routines are called by CLONE (and nothing else) */ |
230 | |
231 | /* Fix entries for one object in all field hashes */ |
232 | void HUF_fix_trigger(SV* trigger, SV* new_id) { |
233 | AV* cont = HUF_get_trigger_content(trigger); |
234 | HV* field_tab = (HV*) *av_fetch(cont, 1, 0); |
235 | HV* new_tab = newHV(); |
236 | HE* ent; |
237 | SV* old_id = *av_fetch(cont, 0, 0); |
238 | hv_iterinit(field_tab); |
239 | while (ent = hv_iternext(field_tab)) { |
240 | SV* field_ref = HeVAL(ent); |
241 | SV* field_id = HUF_field_id(field_ref); |
242 | HV* field = (HV*)SvRV(field_ref); |
243 | SV* val; |
244 | /* recreate field tab entry */ |
245 | hv_store_ent(new_tab, field_id, SvREFCNT_inc(field_ref), 0); |
246 | /* recreate field entry, if any */ |
247 | if (val = hv_delete_ent(field, old_id, 0, 0)) |
248 | hv_store_ent(field, new_id, SvREFCNT_inc(val), 0); |
249 | } |
250 | /* update the trigger */ |
251 | av_store(cont, 0, SvREFCNT_inc(new_id)); |
252 | av_store(cont, 1, (SV*)new_tab); |
253 | } |
254 | |
255 | /* Go over object registry and fix all objects. Also fix the object |
256 | * registry. |
257 | */ |
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258 | void HUF_fix_objects(void) { |
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259 | dMY_CXT; |
260 | I32 i, len; |
261 | HE* ent; |
262 | AV* oblist = (AV*)sv_2mortal((SV*)newAV()); |
263 | hv_iterinit(MY_CXT.ob_reg); |
264 | while(ent = hv_iternext(MY_CXT.ob_reg)) |
265 | av_push(oblist, SvREFCNT_inc(hv_iterkeysv(ent))); |
266 | len = av_len(oblist); |
267 | for (i = 0; i <= len; ++i) { |
268 | SV* old_id = *av_fetch(oblist, i, 0); |
269 | SV* trigger = hv_delete_ent(MY_CXT.ob_reg, old_id, 0, 0); |
270 | SV* new_id = HUF_obj_id(trigger); |
271 | HUF_fix_trigger(trigger, new_id); |
272 | hv_store_ent(MY_CXT.ob_reg, new_id, SvREFCNT_inc(trigger), 0); |
273 | } |
274 | } |
275 | |
276 | /* test support (not needed for functionality) */ |
277 | |
278 | static SV* counter; |
1748121c |
279 | I32 HUF_inc_var(pTHX_ IV index, SV* which) { |
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280 | sv_setiv(counter, 1 + SvIV(counter)); |
281 | return 0; |
282 | } |
283 | |
284 | MODULE = Hash::Util::FieldHash PACKAGE = Hash::Util::FieldHash |
285 | |
286 | BOOT: |
287 | { |
288 | HUF_global(HUF_INIT); /* create variables */ |
289 | } |
290 | |
291 | int |
292 | _fieldhash(SV* href, int mode) |
293 | PROTOTYPE: $$ |
294 | CODE: |
295 | HV* field; |
296 | RETVAL = 0; |
297 | if (mode && |
298 | href && SvROK(href) && |
299 | (field = (HV*)SvRV(href)) && |
300 | SvTYPE(field) == SVt_PVHV |
301 | ) { |
302 | HUF_add_uvar_magic( |
303 | SvRV(href), |
304 | &HUF_watch_key, |
305 | NULL, |
306 | 0, |
307 | NULL |
308 | ); |
309 | RETVAL = HUF_get_status(field); |
310 | } |
311 | OUTPUT: |
312 | RETVAL |
313 | |
314 | void |
87d46f97 |
315 | CLONE(char* classname) |
1e73acc8 |
316 | CODE: |
87d46f97 |
317 | if (0 == strcmp(classname, "Hash::Util::FieldHash")) { |
1e73acc8 |
318 | HUF_global(HUF_CLONE); |
319 | HUF_fix_objects(); |
320 | } |
321 | |
c418a2d4 |
322 | void |
1e73acc8 |
323 | _active_fields(SV* obj) |
324 | PPCODE: |
325 | if (SvROK(obj)) { |
326 | SV* ob_id = HUF_obj_id(obj); |
327 | SV* trigger = HUF_ask_trigger(ob_id); |
328 | if (trigger) { |
329 | AV* cont = HUF_get_trigger_content(trigger); |
330 | HV* field_tab = (HV*) *av_fetch(cont, 1, 0); |
331 | HE* ent; |
332 | hv_iterinit(field_tab); |
333 | while (ent = hv_iternext(field_tab)) { |
334 | HV* field = (HV*)SvRV(HeVAL(ent)); |
335 | if (hv_exists_ent(field, ob_id, 0)) |
336 | XPUSHs(sv_2mortal(newRV_inc((SV*)field))); |
337 | } |
338 | } |
339 | } |
340 | |
341 | void |
342 | _test_uvar_get(SV* svref, SV* countref) |
343 | CODE: |
344 | if (SvROK(svref) && SvROK(countref)) { |
345 | counter = SvRV(countref); |
346 | sv_setiv(counter, 0); |
347 | HUF_add_uvar_magic( |
348 | SvRV(svref), |
349 | &HUF_inc_var, |
350 | NULL, |
351 | 0, |
352 | SvRV(countref) |
353 | ); |
354 | } |
355 | |
356 | void |
357 | _test_uvar_set(SV* svref, SV* countref) |
358 | CODE: |
359 | if (SvROK(svref) && SvROK(countref)) { |
360 | counter = SvRV(countref); |
361 | sv_setiv(counter, 0); |
362 | counter = SvRV(countref); |
363 | HUF_add_uvar_magic( |
364 | SvRV(svref), |
365 | NULL, |
366 | &HUF_inc_var, |
367 | 0, |
368 | SvRV(countref) |
369 | ); |
370 | } |
371 | |
372 | void |
373 | _test_uvar_same(SV* svref, SV* countref) |
374 | CODE: |
375 | if (SvROK(svref) && SvROK(countref)) { |
376 | counter = SvRV(countref); |
377 | sv_setiv(counter, 0); |
378 | HUF_add_uvar_magic( |
379 | SvRV(svref), |
380 | &HUF_inc_var, |
381 | &HUF_inc_var, |
382 | 0, |
383 | NULL |
384 | ); |
385 | } |
386 | |