1 /* This file is part of the Variable::Magic Perl module.
2 * See http://search.cpan.org/dist/Variable-Magic/ */
4 #include <stdio.h> /* sprintf() */
6 #define PERL_NO_GET_CONTEXT
11 #define __PACKAGE__ "Variable::Magic"
13 #define R(S) fprintf(stderr, "R(" #S ") = %d\n", SvREFCNT(S))
15 #define PERL_VERSION_LE(R, V, S) (PERL_REVISION < (R) || (PERL_REVISION == (R) && (PERL_VERSION < (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION <= (S))))))
17 #define PERL_API_VERSION_GE(R, V, S) (PERL_API_REVISION > (R) || (PERL_API_REVISION == (R) && (PERL_API_VERSION > (V) || (PERL_API_VERSION == (V) && (PERL_API_SUBVERSION >= (S))))))
19 /* --- Compatibility ------------------------------------------------------- */
22 # define Newx(v, n, c) New(0, v, n, c)
26 # define SvMAGIC_set(sv, val) (SvMAGIC(sv) = (val))
30 # define MY_CXT vmg_globaldata
32 # define START_MY_CXT STATIC my_cxt_t MY_CXT;
36 #ifndef PERL_MAGIC_ext
37 # define PERL_MAGIC_ext '~'
44 #undef MGf_DUP /* Disable it for now. */
53 #if PERL_API_VERSION_GE(5, 10, 0)
61 /* Bug-free mg_magical - see http://www.xray.mpe.mpg.de/mailing-lists/perl5-porters/2008-01/msg00036.html */
62 STATIC void vmg_mg_magical(pTHX_ SV *sv) {
63 #define vmg_mg_magical(S) vmg_mg_magical(aTHX_ (S))
66 if ((mg = SvMAGIC(sv))) {
69 const MGVTBL* const vtbl = mg->mg_virtual;
71 if (vtbl->svt_get && !(mg->mg_flags & MGf_GSKIP))
78 } while ((mg = mg->mg_moremagic));
79 if (!(SvFLAGS(sv) & (SVs_GMG|SVs_SMG)))
86 /* --- Context-safe global data -------------------------------------------- */
88 #define MY_CXT_KEY __PACKAGE__ "::_guts" XS_VERSION
97 /* --- Signatures ---------------------------------------------------------- */
99 #define SIG_MIN ((U16) (1u << 8))
100 #define SIG_MAX ((U16) (1u << 16 - 1))
101 #define SIG_NBR (SIG_MAX - SIG_MIN + 1)
102 #define SIG_WIZ ((U16) (1u << 8 - 1))
104 /* ... Generate signatures ................................................. */
106 STATIC U16 vmg_gensig(pTHX) {
107 #define vmg_gensig() vmg_gensig(aTHX)
113 sig = SIG_NBR * Drand01() + SIG_MIN;
114 } while (hv_exists(MY_CXT.wizz, buf, sprintf(buf, "%u", sig)));
119 /* --- MGWIZ structure ----------------------------------------------------- */
126 SV *cb_get, *cb_set, *cb_len, *cb_clear, *cb_free;
129 #endif /* MGf_COPY */
135 #endif /* MGf_LOCAL */
137 SV *cb_fetch, *cb_store, *cb_exists, *cb_delete;
138 #endif /* VMG_UVAR */
141 #define MGWIZ2SV(W) (newSVuv(PTR2UV(W)))
142 #define SV2MGWIZ(S) (INT2PTR(MGWIZ*, SvUVX((SV *) (S))))
144 /* ... Construct private data .............................................. */
146 STATIC SV *vmg_data_new(pTHX_ SV *ctor, SV *sv, AV *args) {
147 #define vmg_data_new(C, S, A) vmg_data_new(aTHX_ (C), (S), (A))
157 XPUSHs(sv_2mortal(newRV_inc(sv)));
159 I32 i, alen = av_len(args);
160 for (i = 0; i < alen; ++i) { XPUSHs(*av_fetch(args, i, 0)); }
164 count = call_sv(ctor, G_SCALAR);
168 if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
170 #if PERL_VERSION_LE(5, 8, 2)
171 nsv = sv_newref(nsv); /* Workaround some bug in SvREFCNT_inc() */
173 SvREFCNT_inc(nsv); /* Or it will be destroyed in FREETMPS */
184 STATIC SV *vmg_data_get(SV *sv, U16 sig) {
185 MAGIC *mg, *moremagic;
188 if (SvTYPE(sv) >= SVt_PVMG) {
189 for (mg = SvMAGIC(sv); mg; mg = moremagic) {
190 moremagic = mg->mg_moremagic;
191 if ((mg->mg_type == PERL_MAGIC_ext) && (mg->mg_private == sig)) { break; }
193 if (mg) { return mg->mg_obj; }
199 /* ... Magic cast/dispell .................................................. */
201 STATIC I32 vmg_svt_val(pTHX_ IV, SV *);
203 STATIC void vmg_uvar_del(SV *sv, MAGIC *prevmagic, MAGIC *mg, MAGIC *moremagic) {
205 prevmagic->mg_moremagic = moremagic;
207 SvMAGIC_set(sv, moremagic);
209 mg->mg_moremagic = NULL;
210 Safefree(mg->mg_ptr);
214 STATIC UV vmg_cast(pTHX_ SV *sv, SV *wiz, AV *args) {
215 #define vmg_cast(S, W, A) vmg_cast(aTHX_ (S), (W), (A))
216 MAGIC *mg = NULL, *moremagic = NULL;
222 if (SvTYPE(sv) >= SVt_PVMG) {
223 for (mg = SvMAGIC(sv); mg; mg = moremagic) {
224 moremagic = mg->mg_moremagic;
225 if ((mg->mg_type == PERL_MAGIC_ext) && (mg->mg_private == w->sig)) { break; }
227 if (mg) { return 1; }
230 data = (w->cb_data) ? vmg_data_new(w->cb_data, sv, args) : NULL;
231 mg = sv_magicext(sv, data, PERL_MAGIC_ext, w->vtbl, (const char *) wiz, HEf_SVKEY);
232 mg->mg_private = w->sig;
233 mg->mg_flags = mg->mg_flags
236 #endif /* MGf_COPY */
242 #endif /* MGf_LOCAL */
246 if (w->uvar && SvTYPE(sv) >= SVt_PVHV) {
251 uf[0].uf_val = vmg_svt_val;
258 /* One uvar magic in the chain is enough. */
259 for (prevmagic = NULL, mg = SvMAGIC(sv); mg; prevmagic = mg, mg = moremagic) {
260 moremagic = mg->mg_moremagic;
261 if (mg->mg_type == PERL_MAGIC_uvar) { break; }
264 if (mg) { /* Found another uvar magic. */
265 struct ufuncs *olduf = (struct ufuncs *) mg->mg_ptr;
266 if (olduf->uf_val == vmg_svt_val) {
267 /* It's our uvar magic, nothing to do. */
270 /* It's another uvar magic, backup it and replace it by ours. */
272 vmg_uvar_del(sv, prevmagic, mg, moremagic);
277 sv_magic(sv, NULL, PERL_MAGIC_uvar, (const char *) &uf, sizeof(uf));
282 #endif /* VMG_UVAR */
287 STATIC UV vmg_dispell(pTHX_ SV *sv, U16 sig) {
288 #define vmg_dispell(S, Z) vmg_dispell(aTHX_ (S), (Z))
291 #endif /* VMG_UVAR */
292 MAGIC *mg, *prevmagic, *moremagic = NULL;
294 if (SvTYPE(sv) < SVt_PVMG) { return 0; }
296 for (prevmagic = NULL, mg = SvMAGIC(sv); mg; prevmagic = mg, mg = moremagic) {
297 moremagic = mg->mg_moremagic;
298 if (mg->mg_type == PERL_MAGIC_ext) {
300 MGWIZ *w = SV2MGWIZ(mg->mg_ptr);
301 if (w->uvar) { ++uvars; }
302 #endif /* VMG_UVAR */
303 if (mg->mg_private == sig) {
305 if (!w->uvar) { uvars = 0; } /* Short-circuit uvar deletion. */
306 #endif /* VMG_UVAR */
311 if (!mg) { return 0; }
314 prevmagic->mg_moremagic = moremagic;
316 SvMAGIC_set(sv, moremagic);
318 mg->mg_moremagic = NULL;
320 if (mg->mg_obj != sv) { SvREFCNT_dec(mg->mg_obj); } /* Destroy private data */
321 SvREFCNT_dec((SV *) mg->mg_ptr); /* Unreference the wizard */
325 if (uvars == 1 && SvTYPE(sv) >= SVt_PVHV) {
326 /* mg was the first ext magic in the chain that had uvar */
328 for (mg = moremagic; mg; mg = mg->mg_moremagic) {
329 if ((mg->mg_type == PERL_MAGIC_ext) && SV2MGWIZ(mg->mg_ptr)->uvar) {
337 for (prevmagic = NULL, mg = SvMAGIC(sv); mg; prevmagic = mg, mg = moremagic){
338 moremagic = mg->mg_moremagic;
339 if (mg->mg_type == PERL_MAGIC_uvar) { break; }
342 uf = (struct ufuncs *) mg->mg_ptr;
343 /* assert(uf->uf_val == vmg_svt_val); */
344 if (uf[1].uf_val || uf[1].uf_set) {
345 /* Revert the original uvar magic. */
347 Renew(uf, 1, struct ufuncs);
348 mg->mg_len = sizeof(struct ufuncs);
350 /* Remove the uvar magic. */
351 vmg_uvar_del(sv, prevmagic, mg, moremagic);
355 #endif /* VMG_UVAR */
360 /* ... svt callbacks ....................................................... */
362 STATIC int vmg_cb_call(pTHX_ SV *cb, SV *sv, SV *data) {
363 #define vmg_cb_call(I, S, D) vmg_cb_call(aTHX_ (I), (S), (D))
373 XPUSHs(sv_2mortal(newRV_inc(sv)));
374 if (data) { XPUSHs(data); }
377 count = call_sv(cb, G_SCALAR);
381 if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
392 #if MGf_COPY || VMG_UVAR
393 STATIC int vmg_cb_call2(pTHX_ SV *cb, SV *sv, SV *data, SV *sv2) {
394 #define vmg_cb_call2(I, S, D, S2) vmg_cb_call2(aTHX_ (I), (S), (D), (S2))
404 XPUSHs(sv_2mortal(newRV_inc(sv)));
405 XPUSHs(data ? data : &PL_sv_undef);
406 if (sv2) { XPUSHs(sv2); }
409 count = call_sv(cb, G_SCALAR);
413 if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
423 #endif /* MGf_COPY || VMG_UVAR */
425 STATIC int vmg_svt_get(pTHX_ SV *sv, MAGIC *mg) {
426 return vmg_cb_call(SV2MGWIZ(mg->mg_ptr)->cb_get, sv, mg->mg_obj);
429 STATIC int vmg_svt_set(pTHX_ SV *sv, MAGIC *mg) {
430 return vmg_cb_call(SV2MGWIZ(mg->mg_ptr)->cb_set, sv, mg->mg_obj);
433 STATIC U32 vmg_svt_len(pTHX_ SV *sv, MAGIC *mg) {
443 XPUSHs(sv_2mortal(newRV_inc(sv)));
444 XPUSHs(mg->mg_obj ? mg->mg_obj : &PL_sv_undef);
445 if (SvTYPE(sv) == SVt_PVAV) {
446 XPUSHs(sv_2mortal(newSViv(av_len((AV *) sv) + 1)));
450 count = call_sv(SV2MGWIZ(mg->mg_ptr)->cb_len, G_SCALAR);
454 if (count != 1) { croak("Callback needs to return 1 scalar\n"); }
465 STATIC int vmg_svt_clear(pTHX_ SV *sv, MAGIC *mg) {
466 return vmg_cb_call(SV2MGWIZ(mg->mg_ptr)->cb_clear, sv, mg->mg_obj);
469 STATIC int vmg_svt_free(pTHX_ SV *sv, MAGIC *mg) {
470 /* So that it can survive tmp cleanup in vmg_cb_call */
472 /* Perl_mg_free will get rid of the magic and decrement mg->mg_obj and
473 * mg->mg_ptr reference count */
474 return vmg_cb_call(SV2MGWIZ(mg->mg_ptr)->cb_free, sv, mg->mg_obj);
478 STATIC int vmg_svt_copy(pTHX_ SV *sv, MAGIC *mg, SV *nsv, const char *name, int namelen) {
479 return vmg_cb_call2(SV2MGWIZ(mg->mg_ptr)->cb_copy, sv, mg->mg_obj, nsv);
481 #endif /* MGf_COPY */
484 STATIC int vmg_svt_dup(pTHX_ MAGIC *mg, CLONE_PARAMS *param) {
490 STATIC int vmg_svt_local(pTHX_ SV *nsv, MAGIC *mg) {
491 return vmg_cb_call(SV2MGWIZ(mg->mg_ptr)->cb_local, nsv, mg->mg_obj);
493 #endif /* MGf_LOCAL */
496 STATIC I32 vmg_svt_val(pTHX_ IV action, SV *sv) {
501 mg = mg_find(sv, PERL_MAGIC_uvar);
502 /* mg can't be NULL or we wouldn't be there. */
504 uf = (struct ufuncs *) mg->mg_ptr;
506 if (uf[1].uf_val != NULL) { uf[1].uf_val(aTHX_ action, sv); }
507 if (uf[1].uf_set != NULL) { uf[1].uf_set(aTHX_ action, sv); }
509 action &= HV_FETCH_ISSTORE | HV_FETCH_ISEXISTS | HV_FETCH_LVALUE | HV_DELETE;
510 for (mg = SvMAGIC(sv); mg; mg = mg->mg_moremagic) {
512 if ((mg->mg_type != PERL_MAGIC_ext)
513 || (mg->mg_private < SIG_MIN)
514 || (mg->mg_private > SIG_MAX)) { continue; }
515 w = SV2MGWIZ(mg->mg_ptr);
518 vmg_cb_call2(w->cb_fetch, sv, mg->mg_obj, key);
520 case HV_FETCH_ISSTORE:
521 case HV_FETCH_LVALUE:
522 case (HV_FETCH_ISSTORE|HV_FETCH_LVALUE):
523 vmg_cb_call2(w->cb_store, sv, mg->mg_obj, key);
525 case HV_FETCH_ISEXISTS:
526 vmg_cb_call2(w->cb_exists, sv, mg->mg_obj, key);
529 vmg_cb_call2(w->cb_delete, sv, mg->mg_obj, key);
536 #endif /* VMG_UVAR */
538 /* ... Wizard destructor ................................................... */
540 STATIC int vmg_wizard_free(pTHX_ SV *wiz, MAGIC *mg) {
547 SvREFCNT_inc(wiz); /* Fake survival - it's gonna be deleted anyway */
548 #if PERL_API_VERSION_GE(5, 9, 5)
549 SvREFCNT_inc(wiz); /* One more push */
551 if (hv_delete(MY_CXT.wizz, buf, sprintf(buf, "%u", w->sig), 0)) {
555 if (w->cb_data != NULL) { SvREFCNT_dec(SvRV(w->cb_data)); }
556 if (w->cb_get != NULL) { SvREFCNT_dec(SvRV(w->cb_get)); }
557 if (w->cb_set != NULL) { SvREFCNT_dec(SvRV(w->cb_set)); }
558 if (w->cb_len != NULL) { SvREFCNT_dec(SvRV(w->cb_len)); }
559 if (w->cb_clear != NULL) { SvREFCNT_dec(SvRV(w->cb_clear)); }
560 if (w->cb_free != NULL) { SvREFCNT_dec(SvRV(w->cb_free)); }
562 if (w->cb_copy != NULL) { SvREFCNT_dec(SvRV(w->cb_copy)); }
563 #endif /* MGf_COPY */
565 if (w->cb_dup != NULL) { SvREFCNT_dec(SvRV(w->cb_dup)); }
566 #endif /* MGf_COPY */
568 if (w->cb_local != NULL) { SvREFCNT_dec(SvRV(w->cb_local)); }
569 #endif /* MGf_COPY */
571 if (w->cb_fetch != NULL) { SvREFCNT_dec(SvRV(w->cb_fetch)); }
572 if (w->cb_store != NULL) { SvREFCNT_dec(SvRV(w->cb_store)); }
573 if (w->cb_exists != NULL) { SvREFCNT_dec(SvRV(w->cb_exists)); }
574 if (w->cb_delete != NULL) { SvREFCNT_dec(SvRV(w->cb_delete)); }
575 #endif /* VMG_UVAR */
582 STATIC MGVTBL vmg_wizard_vtbl = {
587 vmg_wizard_free, /* free */
590 #endif /* MGf_COPY */
599 STATIC const char vmg_invalid_wiz[] = "Invalid wizard object";
600 STATIC const char vmg_invalid_sv[] = "Invalid variable";
601 STATIC const char vmg_invalid_sig[] = "Invalid numeric signature";
602 STATIC const char vmg_wrongargnum[] = "Wrong number of arguments";
603 STATIC const char vmg_toomanysigs[] = "Too many magic signatures used";
604 STATIC const char vmg_argstorefailed[] = "Error while storing arguments";
606 STATIC U16 vmg_sv2sig(pTHX_ SV *sv) {
607 #define vmg_sv2sig(S) vmg_sv2sig(aTHX_ (S))
612 } else if (SvNOK(sv)) {
614 } else if ((SvPOK(sv) && grok_number(SvPVX(sv), SvCUR(sv), NULL))) {
617 croak(vmg_invalid_sig);
619 if (sig < SIG_MIN) { sig += SIG_MIN; }
620 if (sig > SIG_MAX) { sig %= SIG_MAX + 1; }
625 #define VMG_SET_CB(S, N) \
627 w->cb_ ## N = (SvOK(cb) && SvROK(cb)) ? newRV_inc(SvRV(cb)) : NULL;
629 #define VMG_SET_SVT_CB(S, N) \
631 if (SvOK(cb) && SvROK(cb)) { \
632 t->svt_ ## N = vmg_svt_ ## N; \
633 w->cb_ ## N = newRV_inc(SvRV(cb)); \
635 t->svt_ ## N = NULL; \
636 w->cb_ ## N = NULL; \
640 /* --- XS ------------------------------------------------------------------ */
642 MODULE = Variable::Magic PACKAGE = Variable::Magic
650 MY_CXT.wizz = newHV();
652 stash = gv_stashpv(__PACKAGE__, 1);
653 newCONSTSUB(stash, "SIG_MIN", newSVuv(SIG_MIN));
654 newCONSTSUB(stash, "SIG_MAX", newSVuv(SIG_MAX));
655 newCONSTSUB(stash, "SIG_NBR", newSVuv(SIG_NBR));
656 newCONSTSUB(stash, "MGf_COPY", newSVuv(MGf_COPY));
657 newCONSTSUB(stash, "MGf_DUP", newSVuv(MGf_DUP));
658 newCONSTSUB(stash, "MGf_LOCAL", newSVuv(MGf_LOCAL));
659 newCONSTSUB(stash, "VMG_UVAR", newSVuv(VMG_UVAR));
680 #endif /* MGf_COPY */
686 #endif /* MGf_LOCAL */
689 #endif /* VMG_UVAR */
690 ) { croak(vmg_wrongargnum); }
695 sig = vmg_sv2sig(svsig);
696 if (old = hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
697 ST(0) = sv_2mortal(newRV_inc(*old));
701 if (MY_CXT.count >= SIG_NBR) { croak(vmg_toomanysigs); }
708 VMG_SET_CB(ST(i++), data);
709 VMG_SET_SVT_CB(ST(i++), get);
710 VMG_SET_SVT_CB(ST(i++), set);
711 VMG_SET_SVT_CB(ST(i++), len);
712 VMG_SET_SVT_CB(ST(i++), clear);
713 VMG_SET_SVT_CB(ST(i++), free);
715 VMG_SET_SVT_CB(ST(i++), copy);
716 #endif /* MGf_COPY */
718 VMG_SET_SVT_CB(ST(i++), dup);
721 VMG_SET_SVT_CB(ST(i++), local);
722 #endif /* MGf_LOCAL */
724 VMG_SET_CB(ST(i++), fetch);
725 VMG_SET_CB(ST(i++), store);
726 VMG_SET_CB(ST(i++), exists);
727 VMG_SET_CB(ST(i++), delete);
728 #endif /* VMG_UVAR */
733 w->uvar = (w->cb_fetch || w->cb_store || w->cb_exists || w->cb_delete);
734 #endif /* VMG_UVAR */
737 mg = sv_magicext(sv, NULL, PERL_MAGIC_ext, &vmg_wizard_vtbl, NULL, -1);
738 mg->mg_private = SIG_WIZ;
740 hv_store(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), sv, 0);
743 RETVAL = newRV_noinc(sv);
751 if (MY_CXT.count >= SIG_NBR) { croak(vmg_toomanysigs); }
752 RETVAL = newSVuv(vmg_gensig());
759 if (!SvROK(wiz)) { croak(vmg_invalid_wiz); }
760 RETVAL = newSVuv(SV2MGWIZ(SvRV(wiz))->sig);
764 SV *cast(SV *sv, SV *wiz, ...)
765 PROTOTYPE: \[$@%&*]$@
773 } else if (SvOK(wiz)) {
776 U16 sig = vmg_sv2sig(wiz);
777 if (old = hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
783 croak(vmg_invalid_sig);
788 av_fill(args, items - 2);
789 for (i = 2; i < items; ++i) {
792 if (av_store(args, i - 2, arg) == NULL) { croak(vmg_argstorefailed); }
795 ret = newSVuv(vmg_cast(SvRV(sv), wiz, args));
801 SV *getdata(SV *sv, SV *wiz)
809 sig = SV2MGWIZ(SvRV(wiz))->sig;
810 } else if (SvOK(wiz)) {
812 sig = vmg_sv2sig(wiz);
813 if (!hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
817 croak(vmg_invalid_wiz);
819 data = vmg_data_get(SvRV(sv), sig);
820 if (!data) { XSRETURN_UNDEF; }
821 ST(0) = newSVsv(data);
824 SV *dispell(SV *sv, SV *wiz)
831 sig = SV2MGWIZ(SvRV(wiz))->sig;
832 } else if (SvOK(wiz)) {
834 sig = vmg_sv2sig(wiz);
835 if (!hv_fetch(MY_CXT.wizz, buf, sprintf(buf, "%u", sig), 0)) {
839 croak(vmg_invalid_wiz);
841 RETVAL = newSVuv(vmg_dispell(SvRV(sv), sig));