3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
36 static const char S_strtab_error[]
37 = "Cannot modify shared string table in hv_%s";
43 HE* he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
44 HE * const heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
46 PL_body_roots[HE_SVSLOT] = he;
48 HeNEXT(he) = (HE*)(he + 1);
56 #define new_HE() (HE*)safemalloc(sizeof(HE))
57 #define del_HE(p) safefree((char*)p)
66 void ** const root = &PL_body_roots[HE_SVSLOT];
76 #define new_HE() new_he()
79 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
80 PL_body_roots[HE_SVSLOT] = p; \
88 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
90 const int flags_masked = flags & HVhek_MASK;
94 Newx(k, HEK_BASESIZE + len + 2, char);
96 Copy(str, HEK_KEY(hek), len, char);
97 HEK_KEY(hek)[len] = 0;
100 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
102 if (flags & HVhek_FREEKEY)
107 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
111 Perl_free_tied_hv_pool(pTHX)
114 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
121 PL_hv_fetch_ent_mh = NULL;
124 #if defined(USE_ITHREADS)
126 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
128 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 PERL_UNUSED_ARG(param);
133 /* We already shared this hash key. */
134 (void)share_hek_hek(shared);
138 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
139 HEK_HASH(source), HEK_FLAGS(source));
140 ptr_table_store(PL_ptr_table, source, shared);
146 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
152 /* look for it in the table first */
153 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
157 /* create anew and remember what it is */
159 ptr_table_store(PL_ptr_table, e, ret);
161 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
162 if (HeKLEN(e) == HEf_SVKEY) {
164 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
165 HeKEY_hek(ret) = (HEK*)k;
166 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
169 /* This is hek_dup inlined, which seems to be important for speed
171 HEK * const source = HeKEY_hek(e);
172 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
175 /* We already shared this hash key. */
176 (void)share_hek_hek(shared);
180 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
181 HEK_HASH(source), HEK_FLAGS(source));
182 ptr_table_store(PL_ptr_table, source, shared);
184 HeKEY_hek(ret) = shared;
187 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
189 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
192 #endif /* USE_ITHREADS */
195 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
198 SV * const sv = sv_newmortal();
199 if (!(flags & HVhek_FREEKEY)) {
200 sv_setpvn(sv, key, klen);
203 /* Need to free saved eventually assign to mortal SV */
204 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
205 sv_usepvn(sv, (char *) key, klen);
207 if (flags & HVhek_UTF8) {
210 Perl_croak(aTHX_ msg, SVfARG(sv));
213 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
219 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
220 the length of the key. The C<hash> parameter is the precomputed hash
221 value; if it is zero then Perl will compute it. The return value will be
222 NULL if the operation failed or if the value did not need to be actually
223 stored within the hash (as in the case of tied hashes). Otherwise it can
224 be dereferenced to get the original C<SV*>. Note that the caller is
225 responsible for suitably incrementing the reference count of C<val> before
226 the call, and decrementing it if the function returned NULL. Effectively
227 a successful hv_store takes ownership of one reference to C<val>. This is
228 usually what you want; a newly created SV has a reference count of one, so
229 if all your code does is create SVs then store them in a hash, hv_store
230 will own the only reference to the new SV, and your code doesn't need to do
231 anything further to tidy up. hv_store is not implemented as a call to
232 hv_store_ent, and does not create a temporary SV for the key, so if your
233 key data is not already in SV form then use hv_store in preference to
236 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
237 information on how to use this function on tied hashes.
243 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
256 hek = hv_fetch_common (hv, NULL, key, klen, flags,
257 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
258 return hek ? &HeVAL(hek) : NULL;
261 /* XXX This looks like an ideal candidate to inline */
263 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
264 register U32 hash, int flags)
266 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
267 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
268 return hek ? &HeVAL(hek) : NULL;
272 =for apidoc hv_store_ent
274 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
275 parameter is the precomputed hash value; if it is zero then Perl will
276 compute it. The return value is the new hash entry so created. It will be
277 NULL if the operation failed or if the value did not need to be actually
278 stored within the hash (as in the case of tied hashes). Otherwise the
279 contents of the return value can be accessed using the C<He?> macros
280 described here. Note that the caller is responsible for suitably
281 incrementing the reference count of C<val> before the call, and
282 decrementing it if the function returned NULL. Effectively a successful
283 hv_store_ent takes ownership of one reference to C<val>. This is
284 usually what you want; a newly created SV has a reference count of one, so
285 if all your code does is create SVs then store them in a hash, hv_store
286 will own the only reference to the new SV, and your code doesn't need to do
287 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
288 unlike C<val> it does not take ownership of it, so maintaining the correct
289 reference count on C<key> is entirely the caller's responsibility. hv_store
290 is not implemented as a call to hv_store_ent, and does not create a temporary
291 SV for the key, so if your key data is not already in SV form then use
292 hv_store in preference to hv_store_ent.
294 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
295 information on how to use this function on tied hashes.
300 /* XXX This looks like an ideal candidate to inline */
302 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
304 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
308 =for apidoc hv_exists
310 Returns a boolean indicating whether the specified hash key exists. The
311 C<klen> is the length of the key.
317 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
329 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
336 Returns the SV which corresponds to the specified key in the hash. The
337 C<klen> is the length of the key. If C<lval> is set then the fetch will be
338 part of a store. Check that the return value is non-null before
339 dereferencing it to an C<SV*>.
341 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
342 information on how to use this function on tied hashes.
348 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
361 hek = hv_fetch_common (hv, NULL, key, klen, flags,
362 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
364 return hek ? &HeVAL(hek) : NULL;
368 =for apidoc hv_exists_ent
370 Returns a boolean indicating whether the specified hash key exists. C<hash>
371 can be a valid precomputed hash value, or 0 to ask for it to be
377 /* XXX This looks like an ideal candidate to inline */
379 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
381 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
385 /* returns an HE * structure with the all fields set */
386 /* note that hent_val will be a mortal sv for MAGICAL hashes */
388 =for apidoc hv_fetch_ent
390 Returns the hash entry which corresponds to the specified key in the hash.
391 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
392 if you want the function to compute it. IF C<lval> is set then the fetch
393 will be part of a store. Make sure the return value is non-null before
394 accessing it. The return value when C<tb> is a tied hash is a pointer to a
395 static location, so be sure to make a copy of the structure if you need to
398 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
399 information on how to use this function on tied hashes.
405 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
407 return hv_fetch_common(hv, keysv, NULL, 0, 0,
408 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
412 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
413 int flags, int action, SV *val, register U32 hash)
426 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
427 keysv = hv_magic_uvar_xkey(hv, keysv, key, klen, flags, action);
428 /* If a fetch-as-store fails on the fetch, then the action is to
429 recurse once into "hv_store". If we didn't do this, then that
430 recursive call would call the key conversion routine again.
431 However, as we replace the original key with the converted
432 key, this would result in a double conversion, which would show
433 up as a bug if the conversion routine is not idempotent. */
437 if (flags & HVhek_FREEKEY)
439 key = SvPV_const(keysv, klen);
441 is_utf8 = (SvUTF8(keysv) != 0);
443 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
446 xhv = (XPVHV*)SvANY(hv);
448 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
449 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
451 /* XXX should be able to skimp on the HE/HEK here when
452 HV_FETCH_JUST_SV is true. */
454 keysv = newSVpvn(key, klen);
459 keysv = newSVsv(keysv);
462 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
464 /* grab a fake HE/HEK pair from the pool or make a new one */
465 entry = PL_hv_fetch_ent_mh;
467 PL_hv_fetch_ent_mh = HeNEXT(entry);
471 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
472 HeKEY_hek(entry) = (HEK*)k;
474 HeNEXT(entry) = NULL;
475 HeSVKEY_set(entry, keysv);
477 sv_upgrade(sv, SVt_PVLV);
479 /* so we can free entry when freeing sv */
480 LvTARG(sv) = (SV*)entry;
482 /* XXX remove at some point? */
483 if (flags & HVhek_FREEKEY)
488 #ifdef ENV_IS_CASELESS
489 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
491 for (i = 0; i < klen; ++i)
492 if (isLOWER(key[i])) {
493 /* Would be nice if we had a routine to do the
494 copy and upercase in a single pass through. */
495 const char * const nkey = strupr(savepvn(key,klen));
496 /* Note that this fetch is for nkey (the uppercased
497 key) whereas the store is for key (the original) */
498 entry = hv_fetch_common(hv, NULL, nkey, klen,
499 HVhek_FREEKEY, /* free nkey */
500 0 /* non-LVAL fetch */
501 | HV_DISABLE_UVAR_XKEY,
503 0 /* compute hash */);
504 if (!entry && (action & HV_FETCH_LVALUE)) {
505 /* This call will free key if necessary.
506 Do it this way to encourage compiler to tail
508 entry = hv_fetch_common(hv, keysv, key, klen,
511 | HV_DISABLE_UVAR_XKEY,
514 if (flags & HVhek_FREEKEY)
522 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
523 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
524 /* I don't understand why hv_exists_ent has svret and sv,
525 whereas hv_exists only had one. */
526 SV * const svret = sv_newmortal();
529 if (keysv || is_utf8) {
531 keysv = newSVpvn(key, klen);
534 keysv = newSVsv(keysv);
536 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
538 mg_copy((SV*)hv, sv, key, klen);
540 if (flags & HVhek_FREEKEY)
542 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
543 /* This cast somewhat evil, but I'm merely using NULL/
544 not NULL to return the boolean exists.
545 And I know hv is not NULL. */
546 return SvTRUE(svret) ? (HE *)hv : NULL;
548 #ifdef ENV_IS_CASELESS
549 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
550 /* XXX This code isn't UTF8 clean. */
551 char * const keysave = (char * const)key;
552 /* Will need to free this, so set FREEKEY flag. */
553 key = savepvn(key,klen);
554 key = (const char*)strupr((char*)key);
559 if (flags & HVhek_FREEKEY) {
562 flags |= HVhek_FREEKEY;
566 else if (action & HV_FETCH_ISSTORE) {
569 hv_magic_check (hv, &needs_copy, &needs_store);
571 const bool save_taint = PL_tainted;
572 if (keysv || is_utf8) {
574 keysv = newSVpvn(key, klen);
578 PL_tainted = SvTAINTED(keysv);
579 keysv = sv_2mortal(newSVsv(keysv));
580 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
582 mg_copy((SV*)hv, val, key, klen);
585 TAINT_IF(save_taint);
587 if (flags & HVhek_FREEKEY)
591 #ifdef ENV_IS_CASELESS
592 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
593 /* XXX This code isn't UTF8 clean. */
594 const char *keysave = key;
595 /* Will need to free this, so set FREEKEY flag. */
596 key = savepvn(key,klen);
597 key = (const char*)strupr((char*)key);
602 if (flags & HVhek_FREEKEY) {
605 flags |= HVhek_FREEKEY;
613 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
614 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
615 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
620 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
622 HvARRAY(hv) = (HE**)array;
624 #ifdef DYNAMIC_ENV_FETCH
625 else if (action & HV_FETCH_ISEXISTS) {
626 /* for an %ENV exists, if we do an insert it's by a recursive
627 store call, so avoid creating HvARRAY(hv) right now. */
631 /* XXX remove at some point? */
632 if (flags & HVhek_FREEKEY)
640 char * const keysave = (char *)key;
641 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
645 flags &= ~HVhek_UTF8;
646 if (key != keysave) {
647 if (flags & HVhek_FREEKEY)
649 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
654 PERL_HASH_INTERNAL(hash, key, klen);
655 /* We don't have a pointer to the hv, so we have to replicate the
656 flag into every HEK, so that hv_iterkeysv can see it. */
657 /* And yes, you do need this even though you are not "storing" because
658 you can flip the flags below if doing an lval lookup. (And that
659 was put in to give the semantics Andreas was expecting.) */
660 flags |= HVhek_REHASH;
662 if (keysv && (SvIsCOW_shared_hash(keysv))) {
663 hash = SvSHARED_HASH(keysv);
665 PERL_HASH(hash, key, klen);
669 masked_flags = (flags & HVhek_MASK);
671 #ifdef DYNAMIC_ENV_FETCH
672 if (!HvARRAY(hv)) entry = NULL;
676 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
678 for (; entry; entry = HeNEXT(entry)) {
679 if (HeHASH(entry) != hash) /* strings can't be equal */
681 if (HeKLEN(entry) != (I32)klen)
683 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
685 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
688 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
689 if (HeKFLAGS(entry) != masked_flags) {
690 /* We match if HVhek_UTF8 bit in our flags and hash key's
691 match. But if entry was set previously with HVhek_WASUTF8
692 and key now doesn't (or vice versa) then we should change
693 the key's flag, as this is assignment. */
694 if (HvSHAREKEYS(hv)) {
695 /* Need to swap the key we have for a key with the flags we
696 need. As keys are shared we can't just write to the
697 flag, so we share the new one, unshare the old one. */
698 HEK * const new_hek = share_hek_flags(key, klen, hash,
700 unshare_hek (HeKEY_hek(entry));
701 HeKEY_hek(entry) = new_hek;
703 else if (hv == PL_strtab) {
704 /* PL_strtab is usually the only hash without HvSHAREKEYS,
705 so putting this test here is cheap */
706 if (flags & HVhek_FREEKEY)
708 Perl_croak(aTHX_ S_strtab_error,
709 action & HV_FETCH_LVALUE ? "fetch" : "store");
712 HeKFLAGS(entry) = masked_flags;
713 if (masked_flags & HVhek_ENABLEHVKFLAGS)
716 if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* yes, can store into placeholder slot */
718 if (action & HV_FETCH_LVALUE) {
720 /* This preserves behaviour with the old hv_fetch
721 implementation which at this point would bail out
722 with a break; (at "if we find a placeholder, we
723 pretend we haven't found anything")
725 That break mean that if a placeholder were found, it
726 caused a call into hv_store, which in turn would
727 check magic, and if there is no magic end up pretty
728 much back at this point (in hv_store's code). */
731 /* LVAL fetch which actaully needs a store. */
733 HvPLACEHOLDERS(hv)--;
736 if (val != &PL_sv_placeholder)
737 HvPLACEHOLDERS(hv)--;
740 } else if (action & HV_FETCH_ISSTORE) {
741 SvREFCNT_dec(HeVAL(entry));
744 } else if (HeVAL(entry) == &PL_sv_placeholder) {
745 /* if we find a placeholder, we pretend we haven't found
749 if (flags & HVhek_FREEKEY)
753 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
754 if (!(action & HV_FETCH_ISSTORE)
755 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
757 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
759 sv = newSVpvn(env,len);
761 return hv_fetch_common(hv, keysv, key, klen, flags,
762 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, sv,
768 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
769 hv_notallowed(flags, key, klen,
770 "Attempt to access disallowed key '%"SVf"' in"
771 " a restricted hash");
773 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
774 /* Not doing some form of store, so return failure. */
775 if (flags & HVhek_FREEKEY)
779 if (action & HV_FETCH_LVALUE) {
782 /* At this point the old hv_fetch code would call to hv_store,
783 which in turn might do some tied magic. So we need to make that
784 magic check happen. */
785 /* gonna assign to this, so it better be there */
786 return hv_fetch_common(hv, keysv, key, klen, flags,
787 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, val,
789 /* XXX Surely that could leak if the fetch-was-store fails?
790 Just like the hv_fetch. */
794 /* Welcome to hv_store... */
797 /* Not sure if we can get here. I think the only case of oentry being
798 NULL is for %ENV with dynamic env fetch. But that should disappear
799 with magic in the previous code. */
802 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
804 HvARRAY(hv) = (HE**)array;
807 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
810 /* share_hek_flags will do the free for us. This might be considered
813 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
814 else if (hv == PL_strtab) {
815 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
816 this test here is cheap */
817 if (flags & HVhek_FREEKEY)
819 Perl_croak(aTHX_ S_strtab_error,
820 action & HV_FETCH_LVALUE ? "fetch" : "store");
822 else /* gotta do the real thing */
823 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
825 HeNEXT(entry) = *oentry;
828 if (val == &PL_sv_placeholder)
829 HvPLACEHOLDERS(hv)++;
830 if (masked_flags & HVhek_ENABLEHVKFLAGS)
834 const HE *counter = HeNEXT(entry);
836 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
837 if (!counter) { /* initial entry? */
838 xhv->xhv_fill++; /* HvFILL(hv)++ */
839 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
841 } else if(!HvREHASH(hv)) {
844 while ((counter = HeNEXT(counter)))
847 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
848 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
849 bucket splits on a rehashed hash, as we're not going to
850 split it again, and if someone is lucky (evil) enough to
851 get all the keys in one list they could exhaust our memory
852 as we repeatedly double the number of buckets on every
853 entry. Linear search feels a less worse thing to do. */
863 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
865 const MAGIC *mg = SvMAGIC(hv);
869 if (isUPPER(mg->mg_type)) {
871 if (mg->mg_type == PERL_MAGIC_tied) {
872 *needs_store = FALSE;
873 return; /* We've set all there is to set. */
876 mg = mg->mg_moremagic;
881 =for apidoc hv_scalar
883 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
889 Perl_hv_scalar(pTHX_ HV *hv)
893 if (SvRMAGICAL(hv)) {
894 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
896 return magic_scalarpack(hv, mg);
901 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
902 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
910 =for apidoc hv_delete
912 Deletes a key/value pair in the hash. The value SV is removed from the
913 hash and returned to the caller. The C<klen> is the length of the key.
914 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
921 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
928 k_flags = HVhek_UTF8;
933 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
937 =for apidoc hv_delete_ent
939 Deletes a key/value pair in the hash. The value SV is removed from the
940 hash and returned to the caller. The C<flags> value will normally be zero;
941 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
942 precomputed hash value, or 0 to ask for it to be computed.
947 /* XXX This looks like an ideal candidate to inline */
949 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
951 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
955 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
956 int k_flags, I32 d_flags, U32 hash)
961 register HE **oentry;
962 HE *const *first_entry;
969 if (SvSMAGICAL(hv) && SvGMAGICAL(hv)
970 && !(d_flags & HV_DISABLE_UVAR_XKEY)) {
971 keysv = hv_magic_uvar_xkey(hv, keysv, key, klen, k_flags, HV_DELETE);
975 if (k_flags & HVhek_FREEKEY)
977 key = SvPV_const(keysv, klen);
979 is_utf8 = (SvUTF8(keysv) != 0);
981 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
984 if (SvRMAGICAL(hv)) {
987 hv_magic_check (hv, &needs_copy, &needs_store);
991 entry = hv_fetch_common(hv, keysv, key, klen,
992 k_flags & ~HVhek_FREEKEY,
993 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
995 sv = entry ? HeVAL(entry) : NULL;
1001 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1002 /* No longer an element */
1003 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1006 return NULL; /* element cannot be deleted */
1008 #ifdef ENV_IS_CASELESS
1009 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1010 /* XXX This code isn't UTF8 clean. */
1011 keysv = sv_2mortal(newSVpvn(key,klen));
1012 if (k_flags & HVhek_FREEKEY) {
1015 key = strupr(SvPVX(keysv));
1024 xhv = (XPVHV*)SvANY(hv);
1029 const char * const keysave = key;
1030 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1033 k_flags |= HVhek_UTF8;
1035 k_flags &= ~HVhek_UTF8;
1036 if (key != keysave) {
1037 if (k_flags & HVhek_FREEKEY) {
1038 /* This shouldn't happen if our caller does what we expect,
1039 but strictly the API allows it. */
1042 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1044 HvHASKFLAGS_on((SV*)hv);
1048 PERL_HASH_INTERNAL(hash, key, klen);
1050 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1051 hash = SvSHARED_HASH(keysv);
1053 PERL_HASH(hash, key, klen);
1057 masked_flags = (k_flags & HVhek_MASK);
1059 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1061 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1063 if (HeHASH(entry) != hash) /* strings can't be equal */
1065 if (HeKLEN(entry) != (I32)klen)
1067 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1069 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1072 if (hv == PL_strtab) {
1073 if (k_flags & HVhek_FREEKEY)
1075 Perl_croak(aTHX_ S_strtab_error, "delete");
1078 /* if placeholder is here, it's already been deleted.... */
1079 if (HeVAL(entry) == &PL_sv_placeholder) {
1080 if (k_flags & HVhek_FREEKEY)
1084 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1085 hv_notallowed(k_flags, key, klen,
1086 "Attempt to delete readonly key '%"SVf"' from"
1087 " a restricted hash");
1089 if (k_flags & HVhek_FREEKEY)
1092 if (d_flags & G_DISCARD)
1095 sv = sv_2mortal(HeVAL(entry));
1096 HeVAL(entry) = &PL_sv_placeholder;
1100 * If a restricted hash, rather than really deleting the entry, put
1101 * a placeholder there. This marks the key as being "approved", so
1102 * we can still access via not-really-existing key without raising
1105 if (SvREADONLY(hv)) {
1106 SvREFCNT_dec(HeVAL(entry));
1107 HeVAL(entry) = &PL_sv_placeholder;
1108 /* We'll be saving this slot, so the number of allocated keys
1109 * doesn't go down, but the number placeholders goes up */
1110 HvPLACEHOLDERS(hv)++;
1112 *oentry = HeNEXT(entry);
1114 xhv->xhv_fill--; /* HvFILL(hv)-- */
1116 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1119 hv_free_ent(hv, entry);
1120 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1121 if (xhv->xhv_keys == 0)
1122 HvHASKFLAGS_off(hv);
1126 if (SvREADONLY(hv)) {
1127 hv_notallowed(k_flags, key, klen,
1128 "Attempt to delete disallowed key '%"SVf"' from"
1129 " a restricted hash");
1132 if (k_flags & HVhek_FREEKEY)
1138 S_hsplit(pTHX_ HV *hv)
1141 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1142 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1143 register I32 newsize = oldsize * 2;
1145 char *a = (char*) HvARRAY(hv);
1147 register HE **oentry;
1148 int longest_chain = 0;
1151 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1152 (void*)hv, (int) oldsize);*/
1154 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1155 /* Can make this clear any placeholders first for non-restricted hashes,
1156 even though Storable rebuilds restricted hashes by putting in all the
1157 placeholders (first) before turning on the readonly flag, because
1158 Storable always pre-splits the hash. */
1159 hv_clear_placeholders(hv);
1163 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1164 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1165 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1171 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1174 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1175 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1180 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1182 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1184 if (oldsize >= 64) {
1185 offer_nice_chunk(HvARRAY(hv),
1186 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1187 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1190 Safefree(HvARRAY(hv));
1194 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1195 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1196 HvARRAY(hv) = (HE**) a;
1199 for (i=0; i<oldsize; i++,aep++) {
1200 int left_length = 0;
1201 int right_length = 0;
1205 if (!*aep) /* non-existent */
1208 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1209 if ((HeHASH(entry) & newsize) != (U32)i) {
1210 *oentry = HeNEXT(entry);
1211 HeNEXT(entry) = *bep;
1213 xhv->xhv_fill++; /* HvFILL(hv)++ */
1219 oentry = &HeNEXT(entry);
1223 if (!*aep) /* everything moved */
1224 xhv->xhv_fill--; /* HvFILL(hv)-- */
1225 /* I think we don't actually need to keep track of the longest length,
1226 merely flag if anything is too long. But for the moment while
1227 developing this code I'll track it. */
1228 if (left_length > longest_chain)
1229 longest_chain = left_length;
1230 if (right_length > longest_chain)
1231 longest_chain = right_length;
1235 /* Pick your policy for "hashing isn't working" here: */
1236 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1241 if (hv == PL_strtab) {
1242 /* Urg. Someone is doing something nasty to the string table.
1247 /* Awooga. Awooga. Pathological data. */
1248 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1249 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1252 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1253 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1255 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1258 was_shared = HvSHAREKEYS(hv);
1261 HvSHAREKEYS_off(hv);
1266 for (i=0; i<newsize; i++,aep++) {
1267 register HE *entry = *aep;
1269 /* We're going to trash this HE's next pointer when we chain it
1270 into the new hash below, so store where we go next. */
1271 HE * const next = HeNEXT(entry);
1276 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1281 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1282 hash, HeKFLAGS(entry));
1283 unshare_hek (HeKEY_hek(entry));
1284 HeKEY_hek(entry) = new_hek;
1286 /* Not shared, so simply write the new hash in. */
1287 HeHASH(entry) = hash;
1289 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1290 HEK_REHASH_on(HeKEY_hek(entry));
1291 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1293 /* Copy oentry to the correct new chain. */
1294 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1296 xhv->xhv_fill++; /* HvFILL(hv)++ */
1297 HeNEXT(entry) = *bep;
1303 Safefree (HvARRAY(hv));
1304 HvARRAY(hv) = (HE **)a;
1308 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1311 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1312 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1313 register I32 newsize;
1318 register HE **oentry;
1320 newsize = (I32) newmax; /* possible truncation here */
1321 if (newsize != newmax || newmax <= oldsize)
1323 while ((newsize & (1 + ~newsize)) != newsize) {
1324 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1326 if (newsize < newmax)
1328 if (newsize < newmax)
1329 return; /* overflow detection */
1331 a = (char *) HvARRAY(hv);
1334 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1335 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1336 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1342 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1345 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1346 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1351 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1353 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1355 if (oldsize >= 64) {
1356 offer_nice_chunk(HvARRAY(hv),
1357 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1358 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1361 Safefree(HvARRAY(hv));
1364 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1367 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1369 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1370 HvARRAY(hv) = (HE **) a;
1371 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1375 for (i=0; i<oldsize; i++,aep++) {
1376 if (!*aep) /* non-existent */
1378 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1379 register I32 j = (HeHASH(entry) & newsize);
1383 *oentry = HeNEXT(entry);
1384 if (!(HeNEXT(entry) = aep[j]))
1385 xhv->xhv_fill++; /* HvFILL(hv)++ */
1390 oentry = &HeNEXT(entry);
1392 if (!*aep) /* everything moved */
1393 xhv->xhv_fill--; /* HvFILL(hv)-- */
1400 Creates a new HV. The reference count is set to 1.
1408 register XPVHV* xhv;
1409 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1410 xhv = (XPVHV*)SvANY(hv);
1412 #ifndef NODEFAULT_SHAREKEYS
1413 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1416 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1417 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1422 Perl_newHVhv(pTHX_ HV *ohv)
1424 HV * const hv = newHV();
1425 STRLEN hv_max, hv_fill;
1427 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1429 hv_max = HvMAX(ohv);
1431 if (!SvMAGICAL((SV *)ohv)) {
1432 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1434 const bool shared = !!HvSHAREKEYS(ohv);
1435 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1437 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1440 /* In each bucket... */
1441 for (i = 0; i <= hv_max; i++) {
1443 HE *oent = oents[i];
1450 /* Copy the linked list of entries. */
1451 for (; oent; oent = HeNEXT(oent)) {
1452 const U32 hash = HeHASH(oent);
1453 const char * const key = HeKEY(oent);
1454 const STRLEN len = HeKLEN(oent);
1455 const int flags = HeKFLAGS(oent);
1456 HE * const ent = new_HE();
1458 HeVAL(ent) = newSVsv(HeVAL(oent));
1460 = shared ? share_hek_flags(key, len, hash, flags)
1461 : save_hek_flags(key, len, hash, flags);
1472 HvFILL(hv) = hv_fill;
1473 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1477 /* Iterate over ohv, copying keys and values one at a time. */
1479 const I32 riter = HvRITER_get(ohv);
1480 HE * const eiter = HvEITER_get(ohv);
1482 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1483 while (hv_max && hv_max + 1 >= hv_fill * 2)
1484 hv_max = hv_max / 2;
1488 while ((entry = hv_iternext_flags(ohv, 0))) {
1489 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1490 newSVsv(HeVAL(entry)), HeHASH(entry),
1493 HvRITER_set(ohv, riter);
1494 HvEITER_set(ohv, eiter);
1500 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1501 magic stays on it. */
1503 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1505 HV * const hv = newHV();
1508 if (ohv && (hv_fill = HvFILL(ohv))) {
1509 STRLEN hv_max = HvMAX(ohv);
1511 const I32 riter = HvRITER_get(ohv);
1512 HE * const eiter = HvEITER_get(ohv);
1514 while (hv_max && hv_max + 1 >= hv_fill * 2)
1515 hv_max = hv_max / 2;
1519 while ((entry = hv_iternext_flags(ohv, 0))) {
1520 SV *const sv = newSVsv(HeVAL(entry));
1521 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1522 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1523 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1524 sv, HeHASH(entry), HeKFLAGS(entry));
1526 HvRITER_set(ohv, riter);
1527 HvEITER_set(ohv, eiter);
1529 hv_magic(hv, NULL, PERL_MAGIC_hints);
1534 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1542 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1543 mro_method_changed_in(hv); /* deletion of method from stash */
1545 if (HeKLEN(entry) == HEf_SVKEY) {
1546 SvREFCNT_dec(HeKEY_sv(entry));
1547 Safefree(HeKEY_hek(entry));
1549 else if (HvSHAREKEYS(hv))
1550 unshare_hek(HeKEY_hek(entry));
1552 Safefree(HeKEY_hek(entry));
1557 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1562 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1563 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1564 if (HeKLEN(entry) == HEf_SVKEY) {
1565 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1567 hv_free_ent(hv, entry);
1571 =for apidoc hv_clear
1573 Clears a hash, making it empty.
1579 Perl_hv_clear(pTHX_ HV *hv)
1582 register XPVHV* xhv;
1586 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1588 xhv = (XPVHV*)SvANY(hv);
1590 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1591 /* restricted hash: convert all keys to placeholders */
1593 for (i = 0; i <= xhv->xhv_max; i++) {
1594 HE *entry = (HvARRAY(hv))[i];
1595 for (; entry; entry = HeNEXT(entry)) {
1596 /* not already placeholder */
1597 if (HeVAL(entry) != &PL_sv_placeholder) {
1598 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1599 SV* const keysv = hv_iterkeysv(entry);
1601 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1604 SvREFCNT_dec(HeVAL(entry));
1605 HeVAL(entry) = &PL_sv_placeholder;
1606 HvPLACEHOLDERS(hv)++;
1614 HvPLACEHOLDERS_set(hv, 0);
1616 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1621 HvHASKFLAGS_off(hv);
1626 mro_isa_changed_in(hv);
1627 HvEITER_set(hv, NULL);
1632 =for apidoc hv_clear_placeholders
1634 Clears any placeholders from a hash. If a restricted hash has any of its keys
1635 marked as readonly and the key is subsequently deleted, the key is not actually
1636 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1637 it so it will be ignored by future operations such as iterating over the hash,
1638 but will still allow the hash to have a value reassigned to the key at some
1639 future point. This function clears any such placeholder keys from the hash.
1640 See Hash::Util::lock_keys() for an example of its use.
1646 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1649 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1652 clear_placeholders(hv, items);
1656 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1666 /* Loop down the linked list heads */
1668 HE **oentry = &(HvARRAY(hv))[i];
1671 while ((entry = *oentry)) {
1672 if (HeVAL(entry) == &PL_sv_placeholder) {
1673 *oentry = HeNEXT(entry);
1674 if (first && !*oentry)
1675 HvFILL(hv)--; /* This linked list is now empty. */
1676 if (entry == HvEITER_get(hv))
1679 hv_free_ent(hv, entry);
1683 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1684 if (HvKEYS(hv) == 0)
1685 HvHASKFLAGS_off(hv);
1686 HvPLACEHOLDERS_set(hv, 0);
1690 oentry = &HeNEXT(entry);
1695 /* You can't get here, hence assertion should always fail. */
1696 assert (items == 0);
1701 S_hfreeentries(pTHX_ HV *hv)
1703 /* This is the array that we're going to restore */
1704 HE **const orig_array = HvARRAY(hv);
1712 /* If the hash is actually a symbol table with a name, look after the
1714 struct xpvhv_aux *iter = HvAUX(hv);
1716 name = iter->xhv_name;
1717 iter->xhv_name = NULL;
1722 /* orig_array remains unchanged throughout the loop. If after freeing all
1723 the entries it turns out that one of the little blighters has triggered
1724 an action that has caused HvARRAY to be re-allocated, then we set
1725 array to the new HvARRAY, and try again. */
1728 /* This is the one we're going to try to empty. First time round
1729 it's the original array. (Hopefully there will only be 1 time
1731 HE ** const array = HvARRAY(hv);
1734 /* Because we have taken xhv_name out, the only allocated pointer
1735 in the aux structure that might exist is the backreference array.
1740 struct mro_meta *meta;
1741 struct xpvhv_aux *iter = HvAUX(hv);
1742 /* If there are weak references to this HV, we need to avoid
1743 freeing them up here. In particular we need to keep the AV
1744 visible as what we're deleting might well have weak references
1745 back to this HV, so the for loop below may well trigger
1746 the removal of backreferences from this array. */
1748 if (iter->xhv_backreferences) {
1749 /* So donate them to regular backref magic to keep them safe.
1750 The sv_magic will increase the reference count of the AV,
1751 so we need to drop it first. */
1752 SvREFCNT_dec(iter->xhv_backreferences);
1753 if (AvFILLp(iter->xhv_backreferences) == -1) {
1754 /* Turns out that the array is empty. Just free it. */
1755 SvREFCNT_dec(iter->xhv_backreferences);
1758 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1759 PERL_MAGIC_backref, NULL, 0);
1761 iter->xhv_backreferences = NULL;
1764 entry = iter->xhv_eiter; /* HvEITER(hv) */
1765 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1767 hv_free_ent(hv, entry);
1769 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1770 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1772 if((meta = iter->xhv_mro_meta)) {
1773 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1774 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1775 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1777 iter->xhv_mro_meta = NULL;
1780 /* There are now no allocated pointers in the aux structure. */
1782 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1783 /* What aux structure? */
1786 /* make everyone else think the array is empty, so that the destructors
1787 * called for freed entries can't recusively mess with us */
1790 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1794 /* Loop down the linked list heads */
1795 HE *entry = array[i];
1798 register HE * const oentry = entry;
1799 entry = HeNEXT(entry);
1800 hv_free_ent(hv, oentry);
1804 /* As there are no allocated pointers in the aux structure, it's now
1805 safe to free the array we just cleaned up, if it's not the one we're
1806 going to put back. */
1807 if (array != orig_array) {
1812 /* Good. No-one added anything this time round. */
1817 /* Someone attempted to iterate or set the hash name while we had
1818 the array set to 0. We'll catch backferences on the next time
1819 round the while loop. */
1820 assert(HvARRAY(hv));
1822 if (HvAUX(hv)->xhv_name) {
1823 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1827 if (--attempts == 0) {
1828 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1832 HvARRAY(hv) = orig_array;
1834 /* If the hash was actually a symbol table, put the name back. */
1836 /* We have restored the original array. If name is non-NULL, then
1837 the original array had an aux structure at the end. So this is
1839 SvFLAGS(hv) |= SVf_OOK;
1840 HvAUX(hv)->xhv_name = name;
1845 =for apidoc hv_undef
1853 Perl_hv_undef(pTHX_ HV *hv)
1856 register XPVHV* xhv;
1861 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1862 xhv = (XPVHV*)SvANY(hv);
1864 if ((name = HvNAME_get(hv)) && !PL_dirty)
1865 mro_isa_changed_in(hv);
1870 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1871 hv_name_set(hv, NULL, 0, 0);
1873 SvFLAGS(hv) &= ~SVf_OOK;
1874 Safefree(HvARRAY(hv));
1875 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1877 HvPLACEHOLDERS_set(hv, 0);
1883 static struct xpvhv_aux*
1884 S_hv_auxinit(HV *hv) {
1885 struct xpvhv_aux *iter;
1889 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1890 + sizeof(struct xpvhv_aux), char);
1892 array = (char *) HvARRAY(hv);
1893 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1894 + sizeof(struct xpvhv_aux), char);
1896 HvARRAY(hv) = (HE**) array;
1897 /* SvOOK_on(hv) attacks the IV flags. */
1898 SvFLAGS(hv) |= SVf_OOK;
1901 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1902 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1904 iter->xhv_backreferences = 0;
1905 iter->xhv_mro_meta = NULL;
1910 =for apidoc hv_iterinit
1912 Prepares a starting point to traverse a hash table. Returns the number of
1913 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1914 currently only meaningful for hashes without tie magic.
1916 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1917 hash buckets that happen to be in use. If you still need that esoteric
1918 value, you can get it through the macro C<HvFILL(tb)>.
1925 Perl_hv_iterinit(pTHX_ HV *hv)
1928 Perl_croak(aTHX_ "Bad hash");
1931 struct xpvhv_aux * const iter = HvAUX(hv);
1932 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1933 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1935 hv_free_ent(hv, entry);
1937 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1938 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1943 /* used to be xhv->xhv_fill before 5.004_65 */
1944 return HvTOTALKEYS(hv);
1948 Perl_hv_riter_p(pTHX_ HV *hv) {
1949 struct xpvhv_aux *iter;
1952 Perl_croak(aTHX_ "Bad hash");
1954 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1955 return &(iter->xhv_riter);
1959 Perl_hv_eiter_p(pTHX_ HV *hv) {
1960 struct xpvhv_aux *iter;
1963 Perl_croak(aTHX_ "Bad hash");
1965 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1966 return &(iter->xhv_eiter);
1970 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1971 struct xpvhv_aux *iter;
1974 Perl_croak(aTHX_ "Bad hash");
1982 iter = hv_auxinit(hv);
1984 iter->xhv_riter = riter;
1988 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1989 struct xpvhv_aux *iter;
1992 Perl_croak(aTHX_ "Bad hash");
1997 /* 0 is the default so don't go malloc()ing a new structure just to
2002 iter = hv_auxinit(hv);
2004 iter->xhv_eiter = eiter;
2008 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2011 struct xpvhv_aux *iter;
2014 PERL_UNUSED_ARG(flags);
2017 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2021 if (iter->xhv_name) {
2022 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2028 iter = hv_auxinit(hv);
2030 PERL_HASH(hash, name, len);
2031 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2035 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2036 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2037 PERL_UNUSED_CONTEXT;
2038 return &(iter->xhv_backreferences);
2042 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2048 av = HvAUX(hv)->xhv_backreferences;
2051 HvAUX(hv)->xhv_backreferences = 0;
2052 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2057 hv_iternext is implemented as a macro in hv.h
2059 =for apidoc hv_iternext
2061 Returns entries from a hash iterator. See C<hv_iterinit>.
2063 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2064 iterator currently points to, without losing your place or invalidating your
2065 iterator. Note that in this case the current entry is deleted from the hash
2066 with your iterator holding the last reference to it. Your iterator is flagged
2067 to free the entry on the next call to C<hv_iternext>, so you must not discard
2068 your iterator immediately else the entry will leak - call C<hv_iternext> to
2069 trigger the resource deallocation.
2071 =for apidoc hv_iternext_flags
2073 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2074 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2075 set the placeholders keys (for restricted hashes) will be returned in addition
2076 to normal keys. By default placeholders are automatically skipped over.
2077 Currently a placeholder is implemented with a value that is
2078 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2079 restricted hashes may change, and the implementation currently is
2080 insufficiently abstracted for any change to be tidy.
2086 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2089 register XPVHV* xhv;
2093 struct xpvhv_aux *iter;
2096 Perl_croak(aTHX_ "Bad hash");
2098 xhv = (XPVHV*)SvANY(hv);
2101 /* Too many things (well, pp_each at least) merrily assume that you can
2102 call iv_iternext without calling hv_iterinit, so we'll have to deal
2108 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2109 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2110 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2111 SV * const key = sv_newmortal();
2113 sv_setsv(key, HeSVKEY_force(entry));
2114 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2120 /* one HE per MAGICAL hash */
2121 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2123 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2125 HeKEY_hek(entry) = hek;
2126 HeKLEN(entry) = HEf_SVKEY;
2128 magic_nextpack((SV*) hv,mg,key);
2130 /* force key to stay around until next time */
2131 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2132 return entry; /* beware, hent_val is not set */
2135 SvREFCNT_dec(HeVAL(entry));
2136 Safefree(HeKEY_hek(entry));
2138 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2142 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2143 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2146 /* The prime_env_iter() on VMS just loaded up new hash values
2147 * so the iteration count needs to be reset back to the beginning
2151 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2156 /* hv_iterint now ensures this. */
2157 assert (HvARRAY(hv));
2159 /* At start of hash, entry is NULL. */
2162 entry = HeNEXT(entry);
2163 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2165 * Skip past any placeholders -- don't want to include them in
2168 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2169 entry = HeNEXT(entry);
2174 /* OK. Come to the end of the current list. Grab the next one. */
2176 iter->xhv_riter++; /* HvRITER(hv)++ */
2177 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2178 /* There is no next one. End of the hash. */
2179 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2182 entry = (HvARRAY(hv))[iter->xhv_riter];
2184 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2185 /* If we have an entry, but it's a placeholder, don't count it.
2187 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2188 entry = HeNEXT(entry);
2190 /* Will loop again if this linked list starts NULL
2191 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2192 or if we run through it and find only placeholders. */
2195 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2197 hv_free_ent(hv, oldentry);
2200 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2201 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2203 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2208 =for apidoc hv_iterkey
2210 Returns the key from the current position of the hash iterator. See
2217 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2219 if (HeKLEN(entry) == HEf_SVKEY) {
2221 char * const p = SvPV(HeKEY_sv(entry), len);
2226 *retlen = HeKLEN(entry);
2227 return HeKEY(entry);
2231 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2233 =for apidoc hv_iterkeysv
2235 Returns the key as an C<SV*> from the current position of the hash
2236 iterator. The return value will always be a mortal copy of the key. Also
2243 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2245 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2249 =for apidoc hv_iterval
2251 Returns the value from the current position of the hash iterator. See
2258 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2260 if (SvRMAGICAL(hv)) {
2261 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2262 SV* const sv = sv_newmortal();
2263 if (HeKLEN(entry) == HEf_SVKEY)
2264 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2266 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2270 return HeVAL(entry);
2274 =for apidoc hv_iternextsv
2276 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2283 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2285 HE * const he = hv_iternext_flags(hv, 0);
2289 *key = hv_iterkey(he, retlen);
2290 return hv_iterval(hv, he);
2297 =for apidoc hv_magic
2299 Adds magic to a hash. See C<sv_magic>.
2304 /* possibly free a shared string if no one has access to it
2305 * len and hash must both be valid for str.
2308 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2310 unshare_hek_or_pvn (NULL, str, len, hash);
2315 Perl_unshare_hek(pTHX_ HEK *hek)
2318 unshare_hek_or_pvn(hek, NULL, 0, 0);
2321 /* possibly free a shared string if no one has access to it
2322 hek if non-NULL takes priority over the other 3, else str, len and hash
2323 are used. If so, len and hash must both be valid for str.
2326 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2329 register XPVHV* xhv;
2331 register HE **oentry;
2333 bool is_utf8 = FALSE;
2335 const char * const save = str;
2336 struct shared_he *he = NULL;
2339 /* Find the shared he which is just before us in memory. */
2340 he = (struct shared_he *)(((char *)hek)
2341 - STRUCT_OFFSET(struct shared_he,
2344 /* Assert that the caller passed us a genuine (or at least consistent)
2346 assert (he->shared_he_he.hent_hek == hek);
2349 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2350 --he->shared_he_he.he_valu.hent_refcount;
2351 UNLOCK_STRTAB_MUTEX;
2354 UNLOCK_STRTAB_MUTEX;
2356 hash = HEK_HASH(hek);
2357 } else if (len < 0) {
2358 STRLEN tmplen = -len;
2360 /* See the note in hv_fetch(). --jhi */
2361 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2364 k_flags = HVhek_UTF8;
2366 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2369 /* what follows was the moral equivalent of:
2370 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2372 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2374 xhv = (XPVHV*)SvANY(PL_strtab);
2375 /* assert(xhv_array != 0) */
2377 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2379 const HE *const he_he = &(he->shared_he_he);
2380 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2385 const int flags_masked = k_flags & HVhek_MASK;
2386 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2387 if (HeHASH(entry) != hash) /* strings can't be equal */
2389 if (HeKLEN(entry) != len)
2391 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2393 if (HeKFLAGS(entry) != flags_masked)
2400 if (--entry->he_valu.hent_refcount == 0) {
2401 *oentry = HeNEXT(entry);
2403 /* There are now no entries in our slot. */
2404 xhv->xhv_fill--; /* HvFILL(hv)-- */
2407 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2411 UNLOCK_STRTAB_MUTEX;
2412 if (!entry && ckWARN_d(WARN_INTERNAL))
2413 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2414 "Attempt to free non-existent shared string '%s'%s"
2416 hek ? HEK_KEY(hek) : str,
2417 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2418 if (k_flags & HVhek_FREEKEY)
2422 /* get a (constant) string ptr from the global string table
2423 * string will get added if it is not already there.
2424 * len and hash must both be valid for str.
2427 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2429 bool is_utf8 = FALSE;
2431 const char * const save = str;
2434 STRLEN tmplen = -len;
2436 /* See the note in hv_fetch(). --jhi */
2437 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2439 /* If we were able to downgrade here, then than means that we were passed
2440 in a key which only had chars 0-255, but was utf8 encoded. */
2443 /* If we found we were able to downgrade the string to bytes, then
2444 we should flag that it needs upgrading on keys or each. Also flag
2445 that we need share_hek_flags to free the string. */
2447 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2450 return share_hek_flags (str, len, hash, flags);
2454 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2458 const int flags_masked = flags & HVhek_MASK;
2459 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2461 /* what follows is the moral equivalent of:
2463 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2464 hv_store(PL_strtab, str, len, NULL, hash);
2466 Can't rehash the shared string table, so not sure if it's worth
2467 counting the number of entries in the linked list
2469 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2470 /* assert(xhv_array != 0) */
2472 entry = (HvARRAY(PL_strtab))[hindex];
2473 for (;entry; entry = HeNEXT(entry)) {
2474 if (HeHASH(entry) != hash) /* strings can't be equal */
2476 if (HeKLEN(entry) != len)
2478 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2480 if (HeKFLAGS(entry) != flags_masked)
2486 /* What used to be head of the list.
2487 If this is NULL, then we're the first entry for this slot, which
2488 means we need to increate fill. */
2489 struct shared_he *new_entry;
2492 HE **const head = &HvARRAY(PL_strtab)[hindex];
2493 HE *const next = *head;
2495 /* We don't actually store a HE from the arena and a regular HEK.
2496 Instead we allocate one chunk of memory big enough for both,
2497 and put the HEK straight after the HE. This way we can find the
2498 HEK directly from the HE.
2501 Newx(k, STRUCT_OFFSET(struct shared_he,
2502 shared_he_hek.hek_key[0]) + len + 2, char);
2503 new_entry = (struct shared_he *)k;
2504 entry = &(new_entry->shared_he_he);
2505 hek = &(new_entry->shared_he_hek);
2507 Copy(str, HEK_KEY(hek), len, char);
2508 HEK_KEY(hek)[len] = 0;
2510 HEK_HASH(hek) = hash;
2511 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2513 /* Still "point" to the HEK, so that other code need not know what
2515 HeKEY_hek(entry) = hek;
2516 entry->he_valu.hent_refcount = 0;
2517 HeNEXT(entry) = next;
2520 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2521 if (!next) { /* initial entry? */
2522 xhv->xhv_fill++; /* HvFILL(hv)++ */
2523 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2528 ++entry->he_valu.hent_refcount;
2529 UNLOCK_STRTAB_MUTEX;
2531 if (flags & HVhek_FREEKEY)
2534 return HeKEY_hek(entry);
2538 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, const char *const key,
2539 const STRLEN klen, const int k_flags, int action)
2542 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2543 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2544 if (uf->uf_set == NULL) {
2545 SV* obj = mg->mg_obj;
2548 keysv = sv_2mortal(newSVpvn(key, klen));
2549 if (k_flags & HVhek_UTF8)
2553 mg->mg_obj = keysv; /* pass key */
2554 uf->uf_index = action; /* pass action */
2555 magic_getuvar((SV*)hv, mg);
2556 keysv = mg->mg_obj; /* may have changed */
2564 Perl_hv_placeholders_p(pTHX_ HV *hv)
2567 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2570 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2573 Perl_die(aTHX_ "panic: hv_placeholders_p");
2576 return &(mg->mg_len);
2581 Perl_hv_placeholders_get(pTHX_ HV *hv)
2584 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2586 return mg ? mg->mg_len : 0;
2590 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2593 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2598 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2599 Perl_die(aTHX_ "panic: hv_placeholders_set");
2601 /* else we don't need to add magic to record 0 placeholders. */
2605 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2609 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2614 value = &PL_sv_placeholder;
2617 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2620 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2623 case HVrhek_PV_UTF8:
2624 /* Create a string SV that directly points to the bytes in our
2626 value = newSV_type(SVt_PV);
2627 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2628 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2629 /* This stops anything trying to free it */
2630 SvLEN_set(value, 0);
2632 SvREADONLY_on(value);
2633 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2637 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2638 he->refcounted_he_data[0]);
2644 =for apidoc refcounted_he_chain_2hv
2646 Generates and returns a C<HV *> by walking up the tree starting at the passed
2647 in C<struct refcounted_he *>.
2652 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2656 U32 placeholders = 0;
2657 /* We could chase the chain once to get an idea of the number of keys,
2658 and call ksplit. But for now we'll make a potentially inefficient
2659 hash with only 8 entries in its array. */
2660 const U32 max = HvMAX(hv);
2664 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2665 HvARRAY(hv) = (HE**)array;
2670 U32 hash = chain->refcounted_he_hash;
2672 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2674 HE **oentry = &((HvARRAY(hv))[hash & max]);
2675 HE *entry = *oentry;
2678 for (; entry; entry = HeNEXT(entry)) {
2679 if (HeHASH(entry) == hash) {
2680 /* We might have a duplicate key here. If so, entry is older
2681 than the key we've already put in the hash, so if they are
2682 the same, skip adding entry. */
2684 const STRLEN klen = HeKLEN(entry);
2685 const char *const key = HeKEY(entry);
2686 if (klen == chain->refcounted_he_keylen
2687 && (!!HeKUTF8(entry)
2688 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2689 && memEQ(key, REF_HE_KEY(chain), klen))
2692 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2694 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2695 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2696 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2707 = share_hek_flags(REF_HE_KEY(chain),
2708 chain->refcounted_he_keylen,
2709 chain->refcounted_he_hash,
2710 (chain->refcounted_he_data[0]
2711 & (HVhek_UTF8|HVhek_WASUTF8)));
2713 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2715 value = refcounted_he_value(chain);
2716 if (value == &PL_sv_placeholder)
2718 HeVAL(entry) = value;
2720 /* Link it into the chain. */
2721 HeNEXT(entry) = *oentry;
2722 if (!HeNEXT(entry)) {
2723 /* initial entry. */
2731 chain = chain->refcounted_he_next;
2735 clear_placeholders(hv, placeholders);
2736 HvTOTALKEYS(hv) -= placeholders;
2739 /* We could check in the loop to see if we encounter any keys with key
2740 flags, but it's probably not worth it, as this per-hash flag is only
2741 really meant as an optimisation for things like Storable. */
2743 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2749 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2750 const char *key, STRLEN klen, int flags, U32 hash)
2753 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2754 of your key has to exactly match that which is stored. */
2755 SV *value = &PL_sv_placeholder;
2759 if (flags & HVhek_FREEKEY)
2761 key = SvPV_const(keysv, klen);
2763 is_utf8 = (SvUTF8(keysv) != 0);
2765 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2769 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2770 hash = SvSHARED_HASH(keysv);
2772 PERL_HASH(hash, key, klen);
2776 for (; chain; chain = chain->refcounted_he_next) {
2778 if (hash != chain->refcounted_he_hash)
2780 if (klen != chain->refcounted_he_keylen)
2782 if (memNE(REF_HE_KEY(chain),key,klen))
2784 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2787 if (hash != HEK_HASH(chain->refcounted_he_hek))
2789 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2791 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2793 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2797 value = sv_2mortal(refcounted_he_value(chain));
2801 if (flags & HVhek_FREEKEY)
2808 =for apidoc refcounted_he_new
2810 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2811 stored in a compact form, all references remain the property of the caller.
2812 The C<struct refcounted_he> is returned with a reference count of 1.
2817 struct refcounted_he *
2818 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2819 SV *const key, SV *const value) {
2821 struct refcounted_he *he;
2823 const char *key_p = SvPV_const(key, key_len);
2824 STRLEN value_len = 0;
2825 const char *value_p = NULL;
2830 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2833 value_type = HVrhek_PV;
2834 } else if (SvIOK(value)) {
2835 value_type = HVrhek_IV;
2836 } else if (value == &PL_sv_placeholder) {
2837 value_type = HVrhek_delete;
2838 } else if (!SvOK(value)) {
2839 value_type = HVrhek_undef;
2841 value_type = HVrhek_PV;
2844 if (value_type == HVrhek_PV) {
2845 value_p = SvPV_const(value, value_len);
2846 key_offset = value_len + 2;
2853 he = (struct refcounted_he*)
2854 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2858 he = (struct refcounted_he*)
2859 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2864 he->refcounted_he_next = parent;
2866 if (value_type == HVrhek_PV) {
2867 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2868 he->refcounted_he_val.refcounted_he_u_len = value_len;
2869 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2870 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2872 value_type = HVrhek_PV_UTF8;
2873 } else if (value_type == HVrhek_IV) {
2875 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2876 value_type = HVrhek_UV;
2878 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2884 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2885 As we're going to be building hash keys from this value in future,
2886 normalise it now. */
2887 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2888 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2890 PERL_HASH(hash, key_p, key_len);
2893 he->refcounted_he_hash = hash;
2894 he->refcounted_he_keylen = key_len;
2895 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2897 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2900 if (flags & HVhek_WASUTF8) {
2901 /* If it was downgraded from UTF-8, then the pointer returned from
2902 bytes_from_utf8 is an allocated pointer that we must free. */
2906 he->refcounted_he_data[0] = flags;
2907 he->refcounted_he_refcnt = 1;
2913 =for apidoc refcounted_he_free
2915 Decrements the reference count of the passed in C<struct refcounted_he *>
2916 by one. If the reference count reaches zero the structure's memory is freed,
2917 and C<refcounted_he_free> iterates onto the parent node.
2923 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2925 PERL_UNUSED_CONTEXT;
2928 struct refcounted_he *copy;
2932 new_count = --he->refcounted_he_refcnt;
2933 HINTS_REFCNT_UNLOCK;
2939 #ifndef USE_ITHREADS
2940 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2943 he = he->refcounted_he_next;
2944 PerlMemShared_free(copy);
2949 =for apidoc hv_assert
2951 Check that a hash is in an internally consistent state.
2959 Perl_hv_assert(pTHX_ HV *hv)
2964 int placeholders = 0;
2967 const I32 riter = HvRITER_get(hv);
2968 HE *eiter = HvEITER_get(hv);
2970 (void)hv_iterinit(hv);
2972 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2973 /* sanity check the values */
2974 if (HeVAL(entry) == &PL_sv_placeholder)
2978 /* sanity check the keys */
2979 if (HeSVKEY(entry)) {
2980 NOOP; /* Don't know what to check on SV keys. */
2981 } else if (HeKUTF8(entry)) {
2983 if (HeKWASUTF8(entry)) {
2984 PerlIO_printf(Perl_debug_log,
2985 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2986 (int) HeKLEN(entry), HeKEY(entry));
2989 } else if (HeKWASUTF8(entry))
2992 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2993 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2994 const int nhashkeys = HvUSEDKEYS(hv);
2995 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2997 if (nhashkeys != real) {
2998 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3001 if (nhashplaceholders != placeholders) {
3002 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3006 if (withflags && ! HvHASKFLAGS(hv)) {
3007 PerlIO_printf(Perl_debug_log,
3008 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3015 HvRITER_set(hv, riter); /* Restore hash iterator state */
3016 HvEITER_set(hv, eiter);
3023 * c-indentation-style: bsd
3025 * indent-tabs-mode: t
3028 * ex: set ts=8 sts=4 sw=4 noet: