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";
46 he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
48 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
49 PL_body_roots[HE_SVSLOT] = he;
51 HeNEXT(he) = (HE*)(he + 1);
59 #define new_HE() (HE*)safemalloc(sizeof(HE))
60 #define del_HE(p) safefree((char*)p)
69 void ** const root = &PL_body_roots[HE_SVSLOT];
79 #define new_HE() new_he()
82 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
83 PL_body_roots[HE_SVSLOT] = p; \
91 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
93 const int flags_masked = flags & HVhek_MASK;
97 Newx(k, HEK_BASESIZE + len + 2, char);
99 Copy(str, HEK_KEY(hek), len, char);
100 HEK_KEY(hek)[len] = 0;
102 HEK_HASH(hek) = hash;
103 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
105 if (flags & HVhek_FREEKEY)
110 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
114 Perl_free_tied_hv_pool(pTHX)
117 HE *he = PL_hv_fetch_ent_mh;
120 Safefree(HeKEY_hek(he));
124 PL_hv_fetch_ent_mh = NULL;
127 #if defined(USE_ITHREADS)
129 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
131 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
133 PERL_UNUSED_ARG(param);
136 /* We already shared this hash key. */
137 (void)share_hek_hek(shared);
141 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
142 HEK_HASH(source), HEK_FLAGS(source));
143 ptr_table_store(PL_ptr_table, source, shared);
149 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
155 /* look for it in the table first */
156 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
160 /* create anew and remember what it is */
162 ptr_table_store(PL_ptr_table, e, ret);
164 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
165 if (HeKLEN(e) == HEf_SVKEY) {
167 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
168 HeKEY_hek(ret) = (HEK*)k;
169 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
172 /* This is hek_dup inlined, which seems to be important for speed
174 HEK * const source = HeKEY_hek(e);
175 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
178 /* We already shared this hash key. */
179 (void)share_hek_hek(shared);
183 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
184 HEK_HASH(source), HEK_FLAGS(source));
185 ptr_table_store(PL_ptr_table, source, shared);
187 HeKEY_hek(ret) = shared;
190 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
192 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
195 #endif /* USE_ITHREADS */
198 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
201 SV * const sv = sv_newmortal();
202 if (!(flags & HVhek_FREEKEY)) {
203 sv_setpvn(sv, key, klen);
206 /* Need to free saved eventually assign to mortal SV */
207 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
208 sv_usepvn(sv, (char *) key, klen);
210 if (flags & HVhek_UTF8) {
213 Perl_croak(aTHX_ msg, SVfARG(sv));
216 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
222 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
223 the length of the key. The C<hash> parameter is the precomputed hash
224 value; if it is zero then Perl will compute it. The return value will be
225 NULL if the operation failed or if the value did not need to be actually
226 stored within the hash (as in the case of tied hashes). Otherwise it can
227 be dereferenced to get the original C<SV*>. Note that the caller is
228 responsible for suitably incrementing the reference count of C<val> before
229 the call, and decrementing it if the function returned NULL. Effectively
230 a successful hv_store takes ownership of one reference to C<val>. This is
231 usually what you want; a newly created SV has a reference count of one, so
232 if all your code does is create SVs then store them in a hash, hv_store
233 will own the only reference to the new SV, and your code doesn't need to do
234 anything further to tidy up. hv_store is not implemented as a call to
235 hv_store_ent, and does not create a temporary SV for the key, so if your
236 key data is not already in SV form then use hv_store in preference to
239 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
240 information on how to use this function on tied hashes.
246 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
259 hek = hv_fetch_common (hv, NULL, key, klen, flags,
260 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
261 return hek ? &HeVAL(hek) : NULL;
264 /* XXX This looks like an ideal candidate to inline */
266 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
267 register U32 hash, int flags)
269 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
270 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
271 return hek ? &HeVAL(hek) : NULL;
275 =for apidoc hv_store_ent
277 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
278 parameter is the precomputed hash value; if it is zero then Perl will
279 compute it. The return value is the new hash entry so created. It will be
280 NULL if the operation failed or if the value did not need to be actually
281 stored within the hash (as in the case of tied hashes). Otherwise the
282 contents of the return value can be accessed using the C<He?> macros
283 described here. Note that the caller is responsible for suitably
284 incrementing the reference count of C<val> before the call, and
285 decrementing it if the function returned NULL. Effectively a successful
286 hv_store_ent takes ownership of one reference to C<val>. This is
287 usually what you want; a newly created SV has a reference count of one, so
288 if all your code does is create SVs then store them in a hash, hv_store
289 will own the only reference to the new SV, and your code doesn't need to do
290 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
291 unlike C<val> it does not take ownership of it, so maintaining the correct
292 reference count on C<key> is entirely the caller's responsibility. hv_store
293 is not implemented as a call to hv_store_ent, and does not create a temporary
294 SV for the key, so if your key data is not already in SV form then use
295 hv_store in preference to hv_store_ent.
297 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
298 information on how to use this function on tied hashes.
303 /* XXX This looks like an ideal candidate to inline */
305 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
307 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
311 =for apidoc hv_exists
313 Returns a boolean indicating whether the specified hash key exists. The
314 C<klen> is the length of the key.
320 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
332 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
339 Returns the SV which corresponds to the specified key in the hash. The
340 C<klen> is the length of the key. If C<lval> is set then the fetch will be
341 part of a store. Check that the return value is non-null before
342 dereferencing it to an C<SV*>.
344 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
345 information on how to use this function on tied hashes.
351 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
364 hek = hv_fetch_common (hv, NULL, key, klen, flags,
365 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
367 return hek ? &HeVAL(hek) : NULL;
371 =for apidoc hv_exists_ent
373 Returns a boolean indicating whether the specified hash key exists. C<hash>
374 can be a valid precomputed hash value, or 0 to ask for it to be
380 /* XXX This looks like an ideal candidate to inline */
382 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
384 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
388 /* returns an HE * structure with the all fields set */
389 /* note that hent_val will be a mortal sv for MAGICAL hashes */
391 =for apidoc hv_fetch_ent
393 Returns the hash entry which corresponds to the specified key in the hash.
394 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
395 if you want the function to compute it. IF C<lval> is set then the fetch
396 will be part of a store. Make sure the return value is non-null before
397 accessing it. The return value when C<tb> is a tied hash is a pointer to a
398 static location, so be sure to make a copy of the structure if you need to
401 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
402 information on how to use this function on tied hashes.
408 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
410 return hv_fetch_common(hv, keysv, NULL, 0, 0,
411 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
415 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
416 int flags, int action, SV *val, register U32 hash)
430 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
431 keysv = hv_magic_uvar_xkey(hv, keysv, action);
432 if (flags & HVhek_FREEKEY)
434 key = SvPV_const(keysv, klen);
436 is_utf8 = (SvUTF8(keysv) != 0);
438 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
441 xhv = (XPVHV*)SvANY(hv);
443 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
444 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
446 /* XXX should be able to skimp on the HE/HEK here when
447 HV_FETCH_JUST_SV is true. */
449 keysv = newSVpvn(key, klen);
454 keysv = newSVsv(keysv);
457 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
459 /* grab a fake HE/HEK pair from the pool or make a new one */
460 entry = PL_hv_fetch_ent_mh;
462 PL_hv_fetch_ent_mh = HeNEXT(entry);
466 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
467 HeKEY_hek(entry) = (HEK*)k;
469 HeNEXT(entry) = NULL;
470 HeSVKEY_set(entry, keysv);
472 sv_upgrade(sv, SVt_PVLV);
474 /* so we can free entry when freeing sv */
475 LvTARG(sv) = (SV*)entry;
477 /* XXX remove at some point? */
478 if (flags & HVhek_FREEKEY)
483 #ifdef ENV_IS_CASELESS
484 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
486 for (i = 0; i < klen; ++i)
487 if (isLOWER(key[i])) {
488 /* Would be nice if we had a routine to do the
489 copy and upercase in a single pass through. */
490 const char * const nkey = strupr(savepvn(key,klen));
491 /* Note that this fetch is for nkey (the uppercased
492 key) whereas the store is for key (the original) */
493 entry = hv_fetch_common(hv, NULL, nkey, klen,
494 HVhek_FREEKEY, /* free nkey */
495 0 /* non-LVAL fetch */,
497 0 /* compute hash */);
498 if (!entry && (action & HV_FETCH_LVALUE)) {
499 /* This call will free key if necessary.
500 Do it this way to encourage compiler to tail
502 entry = hv_fetch_common(hv, keysv, key, klen,
503 flags, HV_FETCH_ISSTORE,
506 if (flags & HVhek_FREEKEY)
514 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
515 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
516 /* I don't understand why hv_exists_ent has svret and sv,
517 whereas hv_exists only had one. */
518 SV * const svret = sv_newmortal();
521 if (keysv || is_utf8) {
523 keysv = newSVpvn(key, klen);
526 keysv = newSVsv(keysv);
528 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
530 mg_copy((SV*)hv, sv, key, klen);
532 if (flags & HVhek_FREEKEY)
534 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
535 /* This cast somewhat evil, but I'm merely using NULL/
536 not NULL to return the boolean exists.
537 And I know hv is not NULL. */
538 return SvTRUE(svret) ? (HE *)hv : NULL;
540 #ifdef ENV_IS_CASELESS
541 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
542 /* XXX This code isn't UTF8 clean. */
543 char * const keysave = (char * const)key;
544 /* Will need to free this, so set FREEKEY flag. */
545 key = savepvn(key,klen);
546 key = (const char*)strupr((char*)key);
551 if (flags & HVhek_FREEKEY) {
554 flags |= HVhek_FREEKEY;
558 else if (action & HV_FETCH_ISSTORE) {
561 hv_magic_check (hv, &needs_copy, &needs_store);
563 const bool save_taint = PL_tainted;
564 if (keysv || is_utf8) {
566 keysv = newSVpvn(key, klen);
570 PL_tainted = SvTAINTED(keysv);
571 keysv = sv_2mortal(newSVsv(keysv));
572 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
574 mg_copy((SV*)hv, val, key, klen);
577 TAINT_IF(save_taint);
579 if (flags & HVhek_FREEKEY)
583 #ifdef ENV_IS_CASELESS
584 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
585 /* XXX This code isn't UTF8 clean. */
586 const char *keysave = key;
587 /* Will need to free this, so set FREEKEY flag. */
588 key = savepvn(key,klen);
589 key = (const char*)strupr((char*)key);
594 if (flags & HVhek_FREEKEY) {
597 flags |= HVhek_FREEKEY;
605 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
606 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
607 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
612 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
614 HvARRAY(hv) = (HE**)array;
616 #ifdef DYNAMIC_ENV_FETCH
617 else if (action & HV_FETCH_ISEXISTS) {
618 /* for an %ENV exists, if we do an insert it's by a recursive
619 store call, so avoid creating HvARRAY(hv) right now. */
623 /* XXX remove at some point? */
624 if (flags & HVhek_FREEKEY)
632 char * const keysave = (char *)key;
633 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
637 flags &= ~HVhek_UTF8;
638 if (key != keysave) {
639 if (flags & HVhek_FREEKEY)
641 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
646 PERL_HASH_INTERNAL(hash, key, klen);
647 /* We don't have a pointer to the hv, so we have to replicate the
648 flag into every HEK, so that hv_iterkeysv can see it. */
649 /* And yes, you do need this even though you are not "storing" because
650 you can flip the flags below if doing an lval lookup. (And that
651 was put in to give the semantics Andreas was expecting.) */
652 flags |= HVhek_REHASH;
654 if (keysv && (SvIsCOW_shared_hash(keysv))) {
655 hash = SvSHARED_HASH(keysv);
657 PERL_HASH(hash, key, klen);
661 masked_flags = (flags & HVhek_MASK);
663 #ifdef DYNAMIC_ENV_FETCH
664 if (!HvARRAY(hv)) entry = NULL;
668 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
670 for (; entry; entry = HeNEXT(entry)) {
671 if (HeHASH(entry) != hash) /* strings can't be equal */
673 if (HeKLEN(entry) != (I32)klen)
675 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
677 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
680 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
681 if (HeKFLAGS(entry) != masked_flags) {
682 /* We match if HVhek_UTF8 bit in our flags and hash key's
683 match. But if entry was set previously with HVhek_WASUTF8
684 and key now doesn't (or vice versa) then we should change
685 the key's flag, as this is assignment. */
686 if (HvSHAREKEYS(hv)) {
687 /* Need to swap the key we have for a key with the flags we
688 need. As keys are shared we can't just write to the
689 flag, so we share the new one, unshare the old one. */
690 HEK * const new_hek = share_hek_flags(key, klen, hash,
692 unshare_hek (HeKEY_hek(entry));
693 HeKEY_hek(entry) = new_hek;
695 else if (hv == PL_strtab) {
696 /* PL_strtab is usually the only hash without HvSHAREKEYS,
697 so putting this test here is cheap */
698 if (flags & HVhek_FREEKEY)
700 Perl_croak(aTHX_ S_strtab_error,
701 action & HV_FETCH_LVALUE ? "fetch" : "store");
704 HeKFLAGS(entry) = masked_flags;
705 if (masked_flags & HVhek_ENABLEHVKFLAGS)
708 if (HeVAL(entry) == &PL_sv_placeholder) {
709 /* yes, can store into placeholder slot */
710 if (action & HV_FETCH_LVALUE) {
712 /* This preserves behaviour with the old hv_fetch
713 implementation which at this point would bail out
714 with a break; (at "if we find a placeholder, we
715 pretend we haven't found anything")
717 That break mean that if a placeholder were found, it
718 caused a call into hv_store, which in turn would
719 check magic, and if there is no magic end up pretty
720 much back at this point (in hv_store's code). */
723 /* LVAL fetch which actaully needs a store. */
725 HvPLACEHOLDERS(hv)--;
728 if (val != &PL_sv_placeholder)
729 HvPLACEHOLDERS(hv)--;
732 } else if (action & HV_FETCH_ISSTORE) {
733 SvREFCNT_dec(HeVAL(entry));
736 } else if (HeVAL(entry) == &PL_sv_placeholder) {
737 /* if we find a placeholder, we pretend we haven't found
741 if (flags & HVhek_FREEKEY)
745 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
746 if (!(action & HV_FETCH_ISSTORE)
747 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
749 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
751 sv = newSVpvn(env,len);
753 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
759 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
760 hv_notallowed(flags, key, klen,
761 "Attempt to access disallowed key '%"SVf"' in"
762 " a restricted hash");
764 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
765 /* Not doing some form of store, so return failure. */
766 if (flags & HVhek_FREEKEY)
770 if (action & HV_FETCH_LVALUE) {
773 /* At this point the old hv_fetch code would call to hv_store,
774 which in turn might do some tied magic. So we need to make that
775 magic check happen. */
776 /* gonna assign to this, so it better be there */
777 return hv_fetch_common(hv, keysv, key, klen, flags,
778 HV_FETCH_ISSTORE, val, hash);
779 /* XXX Surely that could leak if the fetch-was-store fails?
780 Just like the hv_fetch. */
784 /* Welcome to hv_store... */
787 /* Not sure if we can get here. I think the only case of oentry being
788 NULL is for %ENV with dynamic env fetch. But that should disappear
789 with magic in the previous code. */
792 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
794 HvARRAY(hv) = (HE**)array;
797 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
800 /* share_hek_flags will do the free for us. This might be considered
803 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
804 else if (hv == PL_strtab) {
805 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
806 this test here is cheap */
807 if (flags & HVhek_FREEKEY)
809 Perl_croak(aTHX_ S_strtab_error,
810 action & HV_FETCH_LVALUE ? "fetch" : "store");
812 else /* gotta do the real thing */
813 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
815 HeNEXT(entry) = *oentry;
818 if (val == &PL_sv_placeholder)
819 HvPLACEHOLDERS(hv)++;
820 if (masked_flags & HVhek_ENABLEHVKFLAGS)
824 const HE *counter = HeNEXT(entry);
826 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
827 if (!counter) { /* initial entry? */
828 xhv->xhv_fill++; /* HvFILL(hv)++ */
829 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
831 } else if(!HvREHASH(hv)) {
834 while ((counter = HeNEXT(counter)))
837 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
838 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
839 bucket splits on a rehashed hash, as we're not going to
840 split it again, and if someone is lucky (evil) enough to
841 get all the keys in one list they could exhaust our memory
842 as we repeatedly double the number of buckets on every
843 entry. Linear search feels a less worse thing to do. */
853 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
855 const MAGIC *mg = SvMAGIC(hv);
859 if (isUPPER(mg->mg_type)) {
861 if (mg->mg_type == PERL_MAGIC_tied) {
862 *needs_store = FALSE;
863 return; /* We've set all there is to set. */
866 mg = mg->mg_moremagic;
871 =for apidoc hv_scalar
873 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
879 Perl_hv_scalar(pTHX_ HV *hv)
883 if (SvRMAGICAL(hv)) {
884 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
886 return magic_scalarpack(hv, mg);
891 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
892 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
900 =for apidoc hv_delete
902 Deletes a key/value pair in the hash. The value SV is removed from the
903 hash and returned to the caller. The C<klen> is the length of the key.
904 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
911 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
918 k_flags = HVhek_UTF8;
923 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
927 =for apidoc hv_delete_ent
929 Deletes a key/value pair in the hash. The value SV is removed from the
930 hash and returned to the caller. The C<flags> value will normally be zero;
931 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
932 precomputed hash value, or 0 to ask for it to be computed.
937 /* XXX This looks like an ideal candidate to inline */
939 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
941 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
945 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
946 int k_flags, I32 d_flags, U32 hash)
951 register HE **oentry;
952 HE *const *first_entry;
960 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
961 keysv = hv_magic_uvar_xkey(hv, keysv, HV_DELETE);
962 if (k_flags & HVhek_FREEKEY)
964 key = SvPV_const(keysv, klen);
966 is_utf8 = (SvUTF8(keysv) != 0);
968 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
971 if (SvRMAGICAL(hv)) {
974 hv_magic_check (hv, &needs_copy, &needs_store);
978 entry = hv_fetch_common(hv, keysv, key, klen,
979 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
981 sv = entry ? HeVAL(entry) : NULL;
987 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
988 /* No longer an element */
989 sv_unmagic(sv, PERL_MAGIC_tiedelem);
992 return NULL; /* element cannot be deleted */
994 #ifdef ENV_IS_CASELESS
995 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
996 /* XXX This code isn't UTF8 clean. */
997 keysv = sv_2mortal(newSVpvn(key,klen));
998 if (k_flags & HVhek_FREEKEY) {
1001 key = strupr(SvPVX(keysv));
1010 xhv = (XPVHV*)SvANY(hv);
1015 const char * const keysave = key;
1016 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1019 k_flags |= HVhek_UTF8;
1021 k_flags &= ~HVhek_UTF8;
1022 if (key != keysave) {
1023 if (k_flags & HVhek_FREEKEY) {
1024 /* This shouldn't happen if our caller does what we expect,
1025 but strictly the API allows it. */
1028 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1030 HvHASKFLAGS_on((SV*)hv);
1034 PERL_HASH_INTERNAL(hash, key, klen);
1036 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1037 hash = SvSHARED_HASH(keysv);
1039 PERL_HASH(hash, key, klen);
1043 masked_flags = (k_flags & HVhek_MASK);
1045 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1047 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1049 if (HeHASH(entry) != hash) /* strings can't be equal */
1051 if (HeKLEN(entry) != (I32)klen)
1053 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1055 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1058 if (hv == PL_strtab) {
1059 if (k_flags & HVhek_FREEKEY)
1061 Perl_croak(aTHX_ S_strtab_error, "delete");
1064 /* if placeholder is here, it's already been deleted.... */
1065 if (HeVAL(entry) == &PL_sv_placeholder) {
1066 if (k_flags & HVhek_FREEKEY)
1070 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1071 hv_notallowed(k_flags, key, klen,
1072 "Attempt to delete readonly key '%"SVf"' from"
1073 " a restricted hash");
1075 if (k_flags & HVhek_FREEKEY)
1078 if (d_flags & G_DISCARD)
1081 sv = sv_2mortal(HeVAL(entry));
1082 HeVAL(entry) = &PL_sv_placeholder;
1086 * If a restricted hash, rather than really deleting the entry, put
1087 * a placeholder there. This marks the key as being "approved", so
1088 * we can still access via not-really-existing key without raising
1091 if (SvREADONLY(hv)) {
1092 SvREFCNT_dec(HeVAL(entry));
1093 HeVAL(entry) = &PL_sv_placeholder;
1094 /* We'll be saving this slot, so the number of allocated keys
1095 * doesn't go down, but the number placeholders goes up */
1096 HvPLACEHOLDERS(hv)++;
1098 *oentry = HeNEXT(entry);
1100 xhv->xhv_fill--; /* HvFILL(hv)-- */
1102 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1105 hv_free_ent(hv, entry);
1106 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1107 if (xhv->xhv_keys == 0)
1108 HvHASKFLAGS_off(hv);
1112 if (SvREADONLY(hv)) {
1113 hv_notallowed(k_flags, key, klen,
1114 "Attempt to delete disallowed key '%"SVf"' from"
1115 " a restricted hash");
1118 if (k_flags & HVhek_FREEKEY)
1124 S_hsplit(pTHX_ HV *hv)
1127 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1128 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1129 register I32 newsize = oldsize * 2;
1131 char *a = (char*) HvARRAY(hv);
1133 register HE **oentry;
1134 int longest_chain = 0;
1137 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1138 (void*)hv, (int) oldsize);*/
1140 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1141 /* Can make this clear any placeholders first for non-restricted hashes,
1142 even though Storable rebuilds restricted hashes by putting in all the
1143 placeholders (first) before turning on the readonly flag, because
1144 Storable always pre-splits the hash. */
1145 hv_clear_placeholders(hv);
1149 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1150 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1151 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1157 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1160 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1161 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1166 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1168 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1170 if (oldsize >= 64) {
1171 offer_nice_chunk(HvARRAY(hv),
1172 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1173 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1176 Safefree(HvARRAY(hv));
1180 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1181 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1182 HvARRAY(hv) = (HE**) a;
1185 for (i=0; i<oldsize; i++,aep++) {
1186 int left_length = 0;
1187 int right_length = 0;
1191 if (!*aep) /* non-existent */
1194 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1195 if ((HeHASH(entry) & newsize) != (U32)i) {
1196 *oentry = HeNEXT(entry);
1197 HeNEXT(entry) = *bep;
1199 xhv->xhv_fill++; /* HvFILL(hv)++ */
1205 oentry = &HeNEXT(entry);
1209 if (!*aep) /* everything moved */
1210 xhv->xhv_fill--; /* HvFILL(hv)-- */
1211 /* I think we don't actually need to keep track of the longest length,
1212 merely flag if anything is too long. But for the moment while
1213 developing this code I'll track it. */
1214 if (left_length > longest_chain)
1215 longest_chain = left_length;
1216 if (right_length > longest_chain)
1217 longest_chain = right_length;
1221 /* Pick your policy for "hashing isn't working" here: */
1222 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1227 if (hv == PL_strtab) {
1228 /* Urg. Someone is doing something nasty to the string table.
1233 /* Awooga. Awooga. Pathological data. */
1234 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1235 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1238 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1239 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1241 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1244 was_shared = HvSHAREKEYS(hv);
1247 HvSHAREKEYS_off(hv);
1252 for (i=0; i<newsize; i++,aep++) {
1253 register HE *entry = *aep;
1255 /* We're going to trash this HE's next pointer when we chain it
1256 into the new hash below, so store where we go next. */
1257 HE * const next = HeNEXT(entry);
1262 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1267 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1268 hash, HeKFLAGS(entry));
1269 unshare_hek (HeKEY_hek(entry));
1270 HeKEY_hek(entry) = new_hek;
1272 /* Not shared, so simply write the new hash in. */
1273 HeHASH(entry) = hash;
1275 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1276 HEK_REHASH_on(HeKEY_hek(entry));
1277 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1279 /* Copy oentry to the correct new chain. */
1280 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1282 xhv->xhv_fill++; /* HvFILL(hv)++ */
1283 HeNEXT(entry) = *bep;
1289 Safefree (HvARRAY(hv));
1290 HvARRAY(hv) = (HE **)a;
1294 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1297 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1298 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1299 register I32 newsize;
1304 register HE **oentry;
1306 newsize = (I32) newmax; /* possible truncation here */
1307 if (newsize != newmax || newmax <= oldsize)
1309 while ((newsize & (1 + ~newsize)) != newsize) {
1310 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1312 if (newsize < newmax)
1314 if (newsize < newmax)
1315 return; /* overflow detection */
1317 a = (char *) HvARRAY(hv);
1320 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1321 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1322 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1328 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1331 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1332 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1337 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1339 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1341 if (oldsize >= 64) {
1342 offer_nice_chunk(HvARRAY(hv),
1343 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1344 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1347 Safefree(HvARRAY(hv));
1350 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1353 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1355 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1356 HvARRAY(hv) = (HE **) a;
1357 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1361 for (i=0; i<oldsize; i++,aep++) {
1362 if (!*aep) /* non-existent */
1364 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1365 register I32 j = (HeHASH(entry) & newsize);
1369 *oentry = HeNEXT(entry);
1370 if (!(HeNEXT(entry) = aep[j]))
1371 xhv->xhv_fill++; /* HvFILL(hv)++ */
1376 oentry = &HeNEXT(entry);
1378 if (!*aep) /* everything moved */
1379 xhv->xhv_fill--; /* HvFILL(hv)-- */
1386 Creates a new HV. The reference count is set to 1.
1394 register XPVHV* xhv;
1395 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1396 xhv = (XPVHV*)SvANY(hv);
1398 #ifndef NODEFAULT_SHAREKEYS
1399 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1402 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1403 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1408 Perl_newHVhv(pTHX_ HV *ohv)
1410 HV * const hv = newHV();
1411 STRLEN hv_max, hv_fill;
1413 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1415 hv_max = HvMAX(ohv);
1417 if (!SvMAGICAL((SV *)ohv)) {
1418 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1420 const bool shared = !!HvSHAREKEYS(ohv);
1421 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1423 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1426 /* In each bucket... */
1427 for (i = 0; i <= hv_max; i++) {
1429 HE *oent = oents[i];
1436 /* Copy the linked list of entries. */
1437 for (; oent; oent = HeNEXT(oent)) {
1438 const U32 hash = HeHASH(oent);
1439 const char * const key = HeKEY(oent);
1440 const STRLEN len = HeKLEN(oent);
1441 const int flags = HeKFLAGS(oent);
1442 HE * const ent = new_HE();
1444 HeVAL(ent) = newSVsv(HeVAL(oent));
1446 = shared ? share_hek_flags(key, len, hash, flags)
1447 : save_hek_flags(key, len, hash, flags);
1458 HvFILL(hv) = hv_fill;
1459 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1463 /* Iterate over ohv, copying keys and values one at a time. */
1465 const I32 riter = HvRITER_get(ohv);
1466 HE * const eiter = HvEITER_get(ohv);
1468 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1469 while (hv_max && hv_max + 1 >= hv_fill * 2)
1470 hv_max = hv_max / 2;
1474 while ((entry = hv_iternext_flags(ohv, 0))) {
1475 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1476 newSVsv(HeVAL(entry)), HeHASH(entry),
1479 HvRITER_set(ohv, riter);
1480 HvEITER_set(ohv, eiter);
1486 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1487 magic stays on it. */
1489 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1491 HV * const hv = newHV();
1494 if (ohv && (hv_fill = HvFILL(ohv))) {
1495 STRLEN hv_max = HvMAX(ohv);
1497 const I32 riter = HvRITER_get(ohv);
1498 HE * const eiter = HvEITER_get(ohv);
1500 while (hv_max && hv_max + 1 >= hv_fill * 2)
1501 hv_max = hv_max / 2;
1505 while ((entry = hv_iternext_flags(ohv, 0))) {
1506 SV *const sv = newSVsv(HeVAL(entry));
1507 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1508 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1509 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1510 sv, HeHASH(entry), HeKFLAGS(entry));
1512 HvRITER_set(ohv, riter);
1513 HvEITER_set(ohv, eiter);
1515 hv_magic(hv, NULL, PERL_MAGIC_hints);
1520 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1528 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1529 mro_method_changed_in(hv); /* deletion of method from stash */
1531 if (HeKLEN(entry) == HEf_SVKEY) {
1532 SvREFCNT_dec(HeKEY_sv(entry));
1533 Safefree(HeKEY_hek(entry));
1535 else if (HvSHAREKEYS(hv))
1536 unshare_hek(HeKEY_hek(entry));
1538 Safefree(HeKEY_hek(entry));
1543 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1548 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1549 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1550 if (HeKLEN(entry) == HEf_SVKEY) {
1551 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1553 hv_free_ent(hv, entry);
1557 =for apidoc hv_clear
1559 Clears a hash, making it empty.
1565 Perl_hv_clear(pTHX_ HV *hv)
1568 register XPVHV* xhv;
1572 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1574 xhv = (XPVHV*)SvANY(hv);
1576 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1577 /* restricted hash: convert all keys to placeholders */
1579 for (i = 0; i <= xhv->xhv_max; i++) {
1580 HE *entry = (HvARRAY(hv))[i];
1581 for (; entry; entry = HeNEXT(entry)) {
1582 /* not already placeholder */
1583 if (HeVAL(entry) != &PL_sv_placeholder) {
1584 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1585 SV* const keysv = hv_iterkeysv(entry);
1587 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1590 SvREFCNT_dec(HeVAL(entry));
1591 HeVAL(entry) = &PL_sv_placeholder;
1592 HvPLACEHOLDERS(hv)++;
1600 HvPLACEHOLDERS_set(hv, 0);
1602 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1607 HvHASKFLAGS_off(hv);
1611 HvEITER_set(hv, NULL);
1616 =for apidoc hv_clear_placeholders
1618 Clears any placeholders from a hash. If a restricted hash has any of its keys
1619 marked as readonly and the key is subsequently deleted, the key is not actually
1620 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1621 it so it will be ignored by future operations such as iterating over the hash,
1622 but will still allow the hash to have a value reassigned to the key at some
1623 future point. This function clears any such placeholder keys from the hash.
1624 See Hash::Util::lock_keys() for an example of its use.
1630 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1633 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1636 clear_placeholders(hv, items);
1640 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1650 /* Loop down the linked list heads */
1652 HE **oentry = &(HvARRAY(hv))[i];
1655 while ((entry = *oentry)) {
1656 if (HeVAL(entry) == &PL_sv_placeholder) {
1657 *oentry = HeNEXT(entry);
1658 if (first && !*oentry)
1659 HvFILL(hv)--; /* This linked list is now empty. */
1660 if (entry == HvEITER_get(hv))
1663 hv_free_ent(hv, entry);
1667 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1668 if (HvKEYS(hv) == 0)
1669 HvHASKFLAGS_off(hv);
1670 HvPLACEHOLDERS_set(hv, 0);
1674 oentry = &HeNEXT(entry);
1679 /* You can't get here, hence assertion should always fail. */
1680 assert (items == 0);
1685 S_hfreeentries(pTHX_ HV *hv)
1687 /* This is the array that we're going to restore */
1688 HE **const orig_array = HvARRAY(hv);
1696 /* If the hash is actually a symbol table with a name, look after the
1698 struct xpvhv_aux *iter = HvAUX(hv);
1700 name = iter->xhv_name;
1701 iter->xhv_name = NULL;
1706 /* orig_array remains unchanged throughout the loop. If after freeing all
1707 the entries it turns out that one of the little blighters has triggered
1708 an action that has caused HvARRAY to be re-allocated, then we set
1709 array to the new HvARRAY, and try again. */
1712 /* This is the one we're going to try to empty. First time round
1713 it's the original array. (Hopefully there will only be 1 time
1715 HE ** const array = HvARRAY(hv);
1718 /* Because we have taken xhv_name out, the only allocated pointer
1719 in the aux structure that might exist is the backreference array.
1724 struct mro_meta *meta;
1725 struct xpvhv_aux *iter = HvAUX(hv);
1726 /* If there are weak references to this HV, we need to avoid
1727 freeing them up here. In particular we need to keep the AV
1728 visible as what we're deleting might well have weak references
1729 back to this HV, so the for loop below may well trigger
1730 the removal of backreferences from this array. */
1732 if (iter->xhv_backreferences) {
1733 /* So donate them to regular backref magic to keep them safe.
1734 The sv_magic will increase the reference count of the AV,
1735 so we need to drop it first. */
1736 SvREFCNT_dec(iter->xhv_backreferences);
1737 if (AvFILLp(iter->xhv_backreferences) == -1) {
1738 /* Turns out that the array is empty. Just free it. */
1739 SvREFCNT_dec(iter->xhv_backreferences);
1742 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1743 PERL_MAGIC_backref, NULL, 0);
1745 iter->xhv_backreferences = NULL;
1748 entry = iter->xhv_eiter; /* HvEITER(hv) */
1749 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1751 hv_free_ent(hv, entry);
1753 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1754 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1756 if((meta = iter->xhv_mro_meta)) {
1757 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1758 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1759 if(meta->mro_isarev) SvREFCNT_dec(meta->mro_isarev);
1760 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1762 iter->xhv_mro_meta = NULL;
1765 /* There are now no allocated pointers in the aux structure. */
1767 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1768 /* What aux structure? */
1771 /* make everyone else think the array is empty, so that the destructors
1772 * called for freed entries can't recusively mess with us */
1775 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1779 /* Loop down the linked list heads */
1780 HE *entry = array[i];
1783 register HE * const oentry = entry;
1784 entry = HeNEXT(entry);
1785 hv_free_ent(hv, oentry);
1789 /* As there are no allocated pointers in the aux structure, it's now
1790 safe to free the array we just cleaned up, if it's not the one we're
1791 going to put back. */
1792 if (array != orig_array) {
1797 /* Good. No-one added anything this time round. */
1802 /* Someone attempted to iterate or set the hash name while we had
1803 the array set to 0. We'll catch backferences on the next time
1804 round the while loop. */
1805 assert(HvARRAY(hv));
1807 if (HvAUX(hv)->xhv_name) {
1808 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1812 if (--attempts == 0) {
1813 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1817 HvARRAY(hv) = orig_array;
1819 /* If the hash was actually a symbol table, put the name back. */
1821 /* We have restored the original array. If name is non-NULL, then
1822 the original array had an aux structure at the end. So this is
1824 SvFLAGS(hv) |= SVf_OOK;
1825 HvAUX(hv)->xhv_name = name;
1830 =for apidoc hv_undef
1838 Perl_hv_undef(pTHX_ HV *hv)
1841 register XPVHV* xhv;
1846 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1847 xhv = (XPVHV*)SvANY(hv);
1849 if ((name = HvNAME_get(hv))) {
1851 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1852 hv_name_set(hv, NULL, 0, 0);
1854 SvFLAGS(hv) &= ~SVf_OOK;
1855 Safefree(HvARRAY(hv));
1856 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1858 HvPLACEHOLDERS_set(hv, 0);
1864 static struct xpvhv_aux*
1865 S_hv_auxinit(HV *hv) {
1866 struct xpvhv_aux *iter;
1870 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1871 + sizeof(struct xpvhv_aux), char);
1873 array = (char *) HvARRAY(hv);
1874 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1875 + sizeof(struct xpvhv_aux), char);
1877 HvARRAY(hv) = (HE**) array;
1878 /* SvOOK_on(hv) attacks the IV flags. */
1879 SvFLAGS(hv) |= SVf_OOK;
1882 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1883 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1885 iter->xhv_backreferences = 0;
1886 iter->xhv_mro_meta = NULL;
1891 =for apidoc hv_iterinit
1893 Prepares a starting point to traverse a hash table. Returns the number of
1894 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1895 currently only meaningful for hashes without tie magic.
1897 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1898 hash buckets that happen to be in use. If you still need that esoteric
1899 value, you can get it through the macro C<HvFILL(tb)>.
1906 Perl_hv_iterinit(pTHX_ HV *hv)
1909 Perl_croak(aTHX_ "Bad hash");
1912 struct xpvhv_aux * const iter = HvAUX(hv);
1913 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1914 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1916 hv_free_ent(hv, entry);
1918 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1919 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1924 /* used to be xhv->xhv_fill before 5.004_65 */
1925 return HvTOTALKEYS(hv);
1929 Perl_hv_riter_p(pTHX_ HV *hv) {
1930 struct xpvhv_aux *iter;
1933 Perl_croak(aTHX_ "Bad hash");
1935 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1936 return &(iter->xhv_riter);
1940 Perl_hv_eiter_p(pTHX_ HV *hv) {
1941 struct xpvhv_aux *iter;
1944 Perl_croak(aTHX_ "Bad hash");
1946 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1947 return &(iter->xhv_eiter);
1951 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1952 struct xpvhv_aux *iter;
1955 Perl_croak(aTHX_ "Bad hash");
1963 iter = hv_auxinit(hv);
1965 iter->xhv_riter = riter;
1969 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1970 struct xpvhv_aux *iter;
1973 Perl_croak(aTHX_ "Bad hash");
1978 /* 0 is the default so don't go malloc()ing a new structure just to
1983 iter = hv_auxinit(hv);
1985 iter->xhv_eiter = eiter;
1989 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1992 struct xpvhv_aux *iter;
1995 PERL_UNUSED_ARG(flags);
1998 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2002 if (iter->xhv_name) {
2003 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2009 iter = hv_auxinit(hv);
2011 PERL_HASH(hash, name, len);
2012 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2016 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2017 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2018 PERL_UNUSED_CONTEXT;
2019 return &(iter->xhv_backreferences);
2023 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2029 av = HvAUX(hv)->xhv_backreferences;
2032 HvAUX(hv)->xhv_backreferences = 0;
2033 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2038 hv_iternext is implemented as a macro in hv.h
2040 =for apidoc hv_iternext
2042 Returns entries from a hash iterator. See C<hv_iterinit>.
2044 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2045 iterator currently points to, without losing your place or invalidating your
2046 iterator. Note that in this case the current entry is deleted from the hash
2047 with your iterator holding the last reference to it. Your iterator is flagged
2048 to free the entry on the next call to C<hv_iternext>, so you must not discard
2049 your iterator immediately else the entry will leak - call C<hv_iternext> to
2050 trigger the resource deallocation.
2052 =for apidoc hv_iternext_flags
2054 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2055 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2056 set the placeholders keys (for restricted hashes) will be returned in addition
2057 to normal keys. By default placeholders are automatically skipped over.
2058 Currently a placeholder is implemented with a value that is
2059 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2060 restricted hashes may change, and the implementation currently is
2061 insufficiently abstracted for any change to be tidy.
2067 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2070 register XPVHV* xhv;
2074 struct xpvhv_aux *iter;
2077 Perl_croak(aTHX_ "Bad hash");
2079 xhv = (XPVHV*)SvANY(hv);
2082 /* Too many things (well, pp_each at least) merrily assume that you can
2083 call iv_iternext without calling hv_iterinit, so we'll have to deal
2089 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2090 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2091 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2092 SV * const key = sv_newmortal();
2094 sv_setsv(key, HeSVKEY_force(entry));
2095 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2101 /* one HE per MAGICAL hash */
2102 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2104 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2106 HeKEY_hek(entry) = hek;
2107 HeKLEN(entry) = HEf_SVKEY;
2109 magic_nextpack((SV*) hv,mg,key);
2111 /* force key to stay around until next time */
2112 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2113 return entry; /* beware, hent_val is not set */
2116 SvREFCNT_dec(HeVAL(entry));
2117 Safefree(HeKEY_hek(entry));
2119 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2123 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2124 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2127 /* The prime_env_iter() on VMS just loaded up new hash values
2128 * so the iteration count needs to be reset back to the beginning
2132 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2137 /* hv_iterint now ensures this. */
2138 assert (HvARRAY(hv));
2140 /* At start of hash, entry is NULL. */
2143 entry = HeNEXT(entry);
2144 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2146 * Skip past any placeholders -- don't want to include them in
2149 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2150 entry = HeNEXT(entry);
2155 /* OK. Come to the end of the current list. Grab the next one. */
2157 iter->xhv_riter++; /* HvRITER(hv)++ */
2158 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2159 /* There is no next one. End of the hash. */
2160 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2163 entry = (HvARRAY(hv))[iter->xhv_riter];
2165 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2166 /* If we have an entry, but it's a placeholder, don't count it.
2168 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2169 entry = HeNEXT(entry);
2171 /* Will loop again if this linked list starts NULL
2172 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2173 or if we run through it and find only placeholders. */
2176 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2178 hv_free_ent(hv, oldentry);
2181 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2182 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2184 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2189 =for apidoc hv_iterkey
2191 Returns the key from the current position of the hash iterator. See
2198 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2200 if (HeKLEN(entry) == HEf_SVKEY) {
2202 char * const p = SvPV(HeKEY_sv(entry), len);
2207 *retlen = HeKLEN(entry);
2208 return HeKEY(entry);
2212 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2214 =for apidoc hv_iterkeysv
2216 Returns the key as an C<SV*> from the current position of the hash
2217 iterator. The return value will always be a mortal copy of the key. Also
2224 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2226 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2230 =for apidoc hv_iterval
2232 Returns the value from the current position of the hash iterator. See
2239 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2241 if (SvRMAGICAL(hv)) {
2242 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2243 SV* const sv = sv_newmortal();
2244 if (HeKLEN(entry) == HEf_SVKEY)
2245 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2247 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2251 return HeVAL(entry);
2255 =for apidoc hv_iternextsv
2257 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2264 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2266 HE * const he = hv_iternext_flags(hv, 0);
2270 *key = hv_iterkey(he, retlen);
2271 return hv_iterval(hv, he);
2278 =for apidoc hv_magic
2280 Adds magic to a hash. See C<sv_magic>.
2285 /* possibly free a shared string if no one has access to it
2286 * len and hash must both be valid for str.
2289 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2291 unshare_hek_or_pvn (NULL, str, len, hash);
2296 Perl_unshare_hek(pTHX_ HEK *hek)
2299 unshare_hek_or_pvn(hek, NULL, 0, 0);
2302 /* possibly free a shared string if no one has access to it
2303 hek if non-NULL takes priority over the other 3, else str, len and hash
2304 are used. If so, len and hash must both be valid for str.
2307 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2310 register XPVHV* xhv;
2312 register HE **oentry;
2314 bool is_utf8 = FALSE;
2316 const char * const save = str;
2317 struct shared_he *he = NULL;
2320 /* Find the shared he which is just before us in memory. */
2321 he = (struct shared_he *)(((char *)hek)
2322 - STRUCT_OFFSET(struct shared_he,
2325 /* Assert that the caller passed us a genuine (or at least consistent)
2327 assert (he->shared_he_he.hent_hek == hek);
2330 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2331 --he->shared_he_he.he_valu.hent_refcount;
2332 UNLOCK_STRTAB_MUTEX;
2335 UNLOCK_STRTAB_MUTEX;
2337 hash = HEK_HASH(hek);
2338 } else if (len < 0) {
2339 STRLEN tmplen = -len;
2341 /* See the note in hv_fetch(). --jhi */
2342 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2345 k_flags = HVhek_UTF8;
2347 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2350 /* what follows was the moral equivalent of:
2351 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2353 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2355 xhv = (XPVHV*)SvANY(PL_strtab);
2356 /* assert(xhv_array != 0) */
2358 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2360 const HE *const he_he = &(he->shared_he_he);
2361 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2366 const int flags_masked = k_flags & HVhek_MASK;
2367 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2368 if (HeHASH(entry) != hash) /* strings can't be equal */
2370 if (HeKLEN(entry) != len)
2372 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2374 if (HeKFLAGS(entry) != flags_masked)
2381 if (--entry->he_valu.hent_refcount == 0) {
2382 *oentry = HeNEXT(entry);
2384 /* There are now no entries in our slot. */
2385 xhv->xhv_fill--; /* HvFILL(hv)-- */
2388 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2392 UNLOCK_STRTAB_MUTEX;
2393 if (!entry && ckWARN_d(WARN_INTERNAL))
2394 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2395 "Attempt to free non-existent shared string '%s'%s"
2397 hek ? HEK_KEY(hek) : str,
2398 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2399 if (k_flags & HVhek_FREEKEY)
2403 /* get a (constant) string ptr from the global string table
2404 * string will get added if it is not already there.
2405 * len and hash must both be valid for str.
2408 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2410 bool is_utf8 = FALSE;
2412 const char * const save = str;
2415 STRLEN tmplen = -len;
2417 /* See the note in hv_fetch(). --jhi */
2418 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2420 /* If we were able to downgrade here, then than means that we were passed
2421 in a key which only had chars 0-255, but was utf8 encoded. */
2424 /* If we found we were able to downgrade the string to bytes, then
2425 we should flag that it needs upgrading on keys or each. Also flag
2426 that we need share_hek_flags to free the string. */
2428 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2431 return share_hek_flags (str, len, hash, flags);
2435 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2439 const int flags_masked = flags & HVhek_MASK;
2440 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2442 /* what follows is the moral equivalent of:
2444 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2445 hv_store(PL_strtab, str, len, NULL, hash);
2447 Can't rehash the shared string table, so not sure if it's worth
2448 counting the number of entries in the linked list
2450 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2451 /* assert(xhv_array != 0) */
2453 entry = (HvARRAY(PL_strtab))[hindex];
2454 for (;entry; entry = HeNEXT(entry)) {
2455 if (HeHASH(entry) != hash) /* strings can't be equal */
2457 if (HeKLEN(entry) != len)
2459 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2461 if (HeKFLAGS(entry) != flags_masked)
2467 /* What used to be head of the list.
2468 If this is NULL, then we're the first entry for this slot, which
2469 means we need to increate fill. */
2470 struct shared_he *new_entry;
2473 HE **const head = &HvARRAY(PL_strtab)[hindex];
2474 HE *const next = *head;
2476 /* We don't actually store a HE from the arena and a regular HEK.
2477 Instead we allocate one chunk of memory big enough for both,
2478 and put the HEK straight after the HE. This way we can find the
2479 HEK directly from the HE.
2482 Newx(k, STRUCT_OFFSET(struct shared_he,
2483 shared_he_hek.hek_key[0]) + len + 2, char);
2484 new_entry = (struct shared_he *)k;
2485 entry = &(new_entry->shared_he_he);
2486 hek = &(new_entry->shared_he_hek);
2488 Copy(str, HEK_KEY(hek), len, char);
2489 HEK_KEY(hek)[len] = 0;
2491 HEK_HASH(hek) = hash;
2492 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2494 /* Still "point" to the HEK, so that other code need not know what
2496 HeKEY_hek(entry) = hek;
2497 entry->he_valu.hent_refcount = 0;
2498 HeNEXT(entry) = next;
2501 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2502 if (!next) { /* initial entry? */
2503 xhv->xhv_fill++; /* HvFILL(hv)++ */
2504 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2509 ++entry->he_valu.hent_refcount;
2510 UNLOCK_STRTAB_MUTEX;
2512 if (flags & HVhek_FREEKEY)
2515 return HeKEY_hek(entry);
2519 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2522 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2523 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2524 if (uf->uf_set == NULL) {
2525 SV* obj = mg->mg_obj;
2526 mg->mg_obj = keysv; /* pass key */
2527 uf->uf_index = action; /* pass action */
2528 magic_getuvar((SV*)hv, mg);
2529 keysv = mg->mg_obj; /* may have changed */
2537 Perl_hv_placeholders_p(pTHX_ HV *hv)
2540 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2543 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2546 Perl_die(aTHX_ "panic: hv_placeholders_p");
2549 return &(mg->mg_len);
2554 Perl_hv_placeholders_get(pTHX_ HV *hv)
2557 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2559 return mg ? mg->mg_len : 0;
2563 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2566 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2571 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2572 Perl_die(aTHX_ "panic: hv_placeholders_set");
2574 /* else we don't need to add magic to record 0 placeholders. */
2578 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2582 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2587 value = &PL_sv_placeholder;
2590 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2593 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2596 case HVrhek_PV_UTF8:
2597 /* Create a string SV that directly points to the bytes in our
2599 value = newSV_type(SVt_PV);
2600 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2601 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2602 /* This stops anything trying to free it */
2603 SvLEN_set(value, 0);
2605 SvREADONLY_on(value);
2606 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2610 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2611 he->refcounted_he_data[0]);
2617 =for apidoc refcounted_he_chain_2hv
2619 Generates and returns a C<HV *> by walking up the tree starting at the passed
2620 in C<struct refcounted_he *>.
2625 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2629 U32 placeholders = 0;
2630 /* We could chase the chain once to get an idea of the number of keys,
2631 and call ksplit. But for now we'll make a potentially inefficient
2632 hash with only 8 entries in its array. */
2633 const U32 max = HvMAX(hv);
2637 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2638 HvARRAY(hv) = (HE**)array;
2643 U32 hash = chain->refcounted_he_hash;
2645 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2647 HE **oentry = &((HvARRAY(hv))[hash & max]);
2648 HE *entry = *oentry;
2651 for (; entry; entry = HeNEXT(entry)) {
2652 if (HeHASH(entry) == hash) {
2653 /* We might have a duplicate key here. If so, entry is older
2654 than the key we've already put in the hash, so if they are
2655 the same, skip adding entry. */
2657 const STRLEN klen = HeKLEN(entry);
2658 const char *const key = HeKEY(entry);
2659 if (klen == chain->refcounted_he_keylen
2660 && (!!HeKUTF8(entry)
2661 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2662 && memEQ(key, REF_HE_KEY(chain), klen))
2665 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2667 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2668 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2669 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2680 = share_hek_flags(REF_HE_KEY(chain),
2681 chain->refcounted_he_keylen,
2682 chain->refcounted_he_hash,
2683 (chain->refcounted_he_data[0]
2684 & (HVhek_UTF8|HVhek_WASUTF8)));
2686 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2688 value = refcounted_he_value(chain);
2689 if (value == &PL_sv_placeholder)
2691 HeVAL(entry) = value;
2693 /* Link it into the chain. */
2694 HeNEXT(entry) = *oentry;
2695 if (!HeNEXT(entry)) {
2696 /* initial entry. */
2704 chain = chain->refcounted_he_next;
2708 clear_placeholders(hv, placeholders);
2709 HvTOTALKEYS(hv) -= placeholders;
2712 /* We could check in the loop to see if we encounter any keys with key
2713 flags, but it's probably not worth it, as this per-hash flag is only
2714 really meant as an optimisation for things like Storable. */
2716 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2722 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2723 const char *key, STRLEN klen, int flags, U32 hash)
2726 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2727 of your key has to exactly match that which is stored. */
2728 SV *value = &PL_sv_placeholder;
2732 if (flags & HVhek_FREEKEY)
2734 key = SvPV_const(keysv, klen);
2736 is_utf8 = (SvUTF8(keysv) != 0);
2738 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2742 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2743 hash = SvSHARED_HASH(keysv);
2745 PERL_HASH(hash, key, klen);
2749 for (; chain; chain = chain->refcounted_he_next) {
2751 if (hash != chain->refcounted_he_hash)
2753 if (klen != chain->refcounted_he_keylen)
2755 if (memNE(REF_HE_KEY(chain),key,klen))
2757 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2760 if (hash != HEK_HASH(chain->refcounted_he_hek))
2762 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2764 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2766 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2770 value = sv_2mortal(refcounted_he_value(chain));
2774 if (flags & HVhek_FREEKEY)
2781 =for apidoc refcounted_he_new
2783 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2784 stored in a compact form, all references remain the property of the caller.
2785 The C<struct refcounted_he> is returned with a reference count of 1.
2790 struct refcounted_he *
2791 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2792 SV *const key, SV *const value) {
2794 struct refcounted_he *he;
2796 const char *key_p = SvPV_const(key, key_len);
2797 STRLEN value_len = 0;
2798 const char *value_p = NULL;
2803 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2806 value_type = HVrhek_PV;
2807 } else if (SvIOK(value)) {
2808 value_type = HVrhek_IV;
2809 } else if (value == &PL_sv_placeholder) {
2810 value_type = HVrhek_delete;
2811 } else if (!SvOK(value)) {
2812 value_type = HVrhek_undef;
2814 value_type = HVrhek_PV;
2817 if (value_type == HVrhek_PV) {
2818 value_p = SvPV_const(value, value_len);
2819 key_offset = value_len + 2;
2826 he = (struct refcounted_he*)
2827 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2831 he = (struct refcounted_he*)
2832 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2837 he->refcounted_he_next = parent;
2839 if (value_type == HVrhek_PV) {
2840 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2841 he->refcounted_he_val.refcounted_he_u_len = value_len;
2842 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2843 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2845 value_type = HVrhek_PV_UTF8;
2846 } else if (value_type == HVrhek_IV) {
2848 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2849 value_type = HVrhek_UV;
2851 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2857 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2858 As we're going to be building hash keys from this value in future,
2859 normalise it now. */
2860 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2861 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2863 PERL_HASH(hash, key_p, key_len);
2866 he->refcounted_he_hash = hash;
2867 he->refcounted_he_keylen = key_len;
2868 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2870 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2873 if (flags & HVhek_WASUTF8) {
2874 /* If it was downgraded from UTF-8, then the pointer returned from
2875 bytes_from_utf8 is an allocated pointer that we must free. */
2879 he->refcounted_he_data[0] = flags;
2880 he->refcounted_he_refcnt = 1;
2886 =for apidoc refcounted_he_free
2888 Decrements the reference count of the passed in C<struct refcounted_he *>
2889 by one. If the reference count reaches zero the structure's memory is freed,
2890 and C<refcounted_he_free> iterates onto the parent node.
2896 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2898 PERL_UNUSED_CONTEXT;
2901 struct refcounted_he *copy;
2905 new_count = --he->refcounted_he_refcnt;
2906 HINTS_REFCNT_UNLOCK;
2912 #ifndef USE_ITHREADS
2913 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2916 he = he->refcounted_he_next;
2917 PerlMemShared_free(copy);
2922 =for apidoc hv_assert
2924 Check that a hash is in an internally consistent state.
2932 Perl_hv_assert(pTHX_ HV *hv)
2937 int placeholders = 0;
2940 const I32 riter = HvRITER_get(hv);
2941 HE *eiter = HvEITER_get(hv);
2943 (void)hv_iterinit(hv);
2945 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2946 /* sanity check the values */
2947 if (HeVAL(entry) == &PL_sv_placeholder)
2951 /* sanity check the keys */
2952 if (HeSVKEY(entry)) {
2953 NOOP; /* Don't know what to check on SV keys. */
2954 } else if (HeKUTF8(entry)) {
2956 if (HeKWASUTF8(entry)) {
2957 PerlIO_printf(Perl_debug_log,
2958 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2959 (int) HeKLEN(entry), HeKEY(entry));
2962 } else if (HeKWASUTF8(entry))
2965 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2966 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2967 const int nhashkeys = HvUSEDKEYS(hv);
2968 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2970 if (nhashkeys != real) {
2971 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2974 if (nhashplaceholders != placeholders) {
2975 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2979 if (withflags && ! HvHASKFLAGS(hv)) {
2980 PerlIO_printf(Perl_debug_log,
2981 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2988 HvRITER_set(hv, riter); /* Restore hash iterator state */
2989 HvEITER_set(hv, eiter);
2996 * c-indentation-style: bsd
2998 * indent-tabs-mode: t
3001 * ex: set ts=8 sts=4 sw=4 noet: