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_common(hv, NULL, key, klen, flags,
257 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
258 return hek ? &HeVAL(hek) : NULL;
261 /* Tricky to inlike this because it needs a temporary variable */
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_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.
301 =for apidoc hv_exists
303 Returns a boolean indicating whether the specified hash key exists. The
304 C<klen> is the length of the key.
310 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
322 return hv_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
329 Returns the SV which corresponds to the specified key in the hash. The
330 C<klen> is the length of the key. If C<lval> is set then the fetch will be
331 part of a store. Check that the return value is non-null before
332 dereferencing it to an C<SV*>.
334 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
335 information on how to use this function on tied hashes.
341 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
354 hek = hv_common(hv, NULL, key, klen, flags, lval
355 ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
357 return hek ? &HeVAL(hek) : NULL;
361 =for apidoc hv_exists_ent
363 Returns a boolean indicating whether the specified hash key exists. C<hash>
364 can be a valid precomputed hash value, or 0 to ask for it to be
370 /* returns an HE * structure with the all fields set */
371 /* note that hent_val will be a mortal sv for MAGICAL hashes */
373 =for apidoc hv_fetch_ent
375 Returns the hash entry which corresponds to the specified key in the hash.
376 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
377 if you want the function to compute it. IF C<lval> is set then the fetch
378 will be part of a store. Make sure the return value is non-null before
379 accessing it. The return value when C<tb> is a tied hash is a pointer to a
380 static location, so be sure to make a copy of the structure if you need to
383 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
384 information on how to use this function on tied hashes.
390 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
391 int flags, int action, SV *val, register U32 hash)
403 if (SvTYPE(hv) == SVTYPEMASK)
406 assert(SvTYPE(hv) == SVt_PVHV);
408 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
410 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
411 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
412 if (uf->uf_set == NULL) {
413 SV* obj = mg->mg_obj;
416 keysv = sv_2mortal(newSVpvn(key, klen));
417 if (flags & HVhek_UTF8)
421 mg->mg_obj = keysv; /* pass key */
422 uf->uf_index = action; /* pass action */
423 magic_getuvar((SV*)hv, mg);
424 keysv = mg->mg_obj; /* may have changed */
427 /* If the key may have changed, then we need to invalidate
428 any passed-in computed hash value. */
434 if (flags & HVhek_FREEKEY)
436 key = SvPV_const(keysv, klen);
438 is_utf8 = (SvUTF8(keysv) != 0);
440 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
443 if (action & HV_DELETE) {
444 return (HE *) hv_delete_common(hv, keysv, key, klen,
445 flags | (is_utf8 ? HVhek_UTF8 : 0),
449 xhv = (XPVHV*)SvANY(hv);
451 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
452 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
454 /* XXX should be able to skimp on the HE/HEK here when
455 HV_FETCH_JUST_SV is true. */
457 keysv = newSVpvn(key, klen);
462 keysv = newSVsv(keysv);
465 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
467 /* grab a fake HE/HEK pair from the pool or make a new one */
468 entry = PL_hv_fetch_ent_mh;
470 PL_hv_fetch_ent_mh = HeNEXT(entry);
474 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
475 HeKEY_hek(entry) = (HEK*)k;
477 HeNEXT(entry) = NULL;
478 HeSVKEY_set(entry, keysv);
480 sv_upgrade(sv, SVt_PVLV);
482 /* so we can free entry when freeing sv */
483 LvTARG(sv) = (SV*)entry;
485 /* XXX remove at some point? */
486 if (flags & HVhek_FREEKEY)
491 #ifdef ENV_IS_CASELESS
492 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
494 for (i = 0; i < klen; ++i)
495 if (isLOWER(key[i])) {
496 /* Would be nice if we had a routine to do the
497 copy and upercase in a single pass through. */
498 const char * const nkey = strupr(savepvn(key,klen));
499 /* Note that this fetch is for nkey (the uppercased
500 key) whereas the store is for key (the original) */
501 entry = hv_common(hv, NULL, nkey, klen,
502 HVhek_FREEKEY, /* free nkey */
503 0 /* non-LVAL fetch */
504 | HV_DISABLE_UVAR_XKEY,
506 0 /* compute hash */);
507 if (!entry && (action & HV_FETCH_LVALUE)) {
508 /* This call will free key if necessary.
509 Do it this way to encourage compiler to tail
511 entry = hv_common(hv, keysv, key, klen,
514 | HV_DISABLE_UVAR_XKEY,
517 if (flags & HVhek_FREEKEY)
525 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
526 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
527 /* I don't understand why hv_exists_ent has svret and sv,
528 whereas hv_exists only had one. */
529 SV * const svret = sv_newmortal();
532 if (keysv || is_utf8) {
534 keysv = newSVpvn(key, klen);
537 keysv = newSVsv(keysv);
539 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
541 mg_copy((SV*)hv, sv, key, klen);
543 if (flags & HVhek_FREEKEY)
545 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
546 /* This cast somewhat evil, but I'm merely using NULL/
547 not NULL to return the boolean exists.
548 And I know hv is not NULL. */
549 return SvTRUE(svret) ? (HE *)hv : NULL;
551 #ifdef ENV_IS_CASELESS
552 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
553 /* XXX This code isn't UTF8 clean. */
554 char * const keysave = (char * const)key;
555 /* Will need to free this, so set FREEKEY flag. */
556 key = savepvn(key,klen);
557 key = (const char*)strupr((char*)key);
562 if (flags & HVhek_FREEKEY) {
565 flags |= HVhek_FREEKEY;
569 else if (action & HV_FETCH_ISSTORE) {
572 hv_magic_check (hv, &needs_copy, &needs_store);
574 const bool save_taint = PL_tainted;
575 if (keysv || is_utf8) {
577 keysv = newSVpvn(key, klen);
581 PL_tainted = SvTAINTED(keysv);
582 keysv = sv_2mortal(newSVsv(keysv));
583 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
585 mg_copy((SV*)hv, val, key, klen);
588 TAINT_IF(save_taint);
590 if (flags & HVhek_FREEKEY)
594 #ifdef ENV_IS_CASELESS
595 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
596 /* XXX This code isn't UTF8 clean. */
597 const char *keysave = key;
598 /* Will need to free this, so set FREEKEY flag. */
599 key = savepvn(key,klen);
600 key = (const char*)strupr((char*)key);
605 if (flags & HVhek_FREEKEY) {
608 flags |= HVhek_FREEKEY;
616 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
617 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
618 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
623 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
625 HvARRAY(hv) = (HE**)array;
627 #ifdef DYNAMIC_ENV_FETCH
628 else if (action & HV_FETCH_ISEXISTS) {
629 /* for an %ENV exists, if we do an insert it's by a recursive
630 store call, so avoid creating HvARRAY(hv) right now. */
634 /* XXX remove at some point? */
635 if (flags & HVhek_FREEKEY)
643 char * const keysave = (char *)key;
644 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
648 flags &= ~HVhek_UTF8;
649 if (key != keysave) {
650 if (flags & HVhek_FREEKEY)
652 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
657 PERL_HASH_INTERNAL(hash, key, klen);
658 /* We don't have a pointer to the hv, so we have to replicate the
659 flag into every HEK, so that hv_iterkeysv can see it. */
660 /* And yes, you do need this even though you are not "storing" because
661 you can flip the flags below if doing an lval lookup. (And that
662 was put in to give the semantics Andreas was expecting.) */
663 flags |= HVhek_REHASH;
665 if (keysv && (SvIsCOW_shared_hash(keysv))) {
666 hash = SvSHARED_HASH(keysv);
668 PERL_HASH(hash, key, klen);
672 masked_flags = (flags & HVhek_MASK);
674 #ifdef DYNAMIC_ENV_FETCH
675 if (!HvARRAY(hv)) entry = NULL;
679 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
681 for (; entry; entry = HeNEXT(entry)) {
682 if (HeHASH(entry) != hash) /* strings can't be equal */
684 if (HeKLEN(entry) != (I32)klen)
686 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
688 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
691 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
692 if (HeKFLAGS(entry) != masked_flags) {
693 /* We match if HVhek_UTF8 bit in our flags and hash key's
694 match. But if entry was set previously with HVhek_WASUTF8
695 and key now doesn't (or vice versa) then we should change
696 the key's flag, as this is assignment. */
697 if (HvSHAREKEYS(hv)) {
698 /* Need to swap the key we have for a key with the flags we
699 need. As keys are shared we can't just write to the
700 flag, so we share the new one, unshare the old one. */
701 HEK * const new_hek = share_hek_flags(key, klen, hash,
703 unshare_hek (HeKEY_hek(entry));
704 HeKEY_hek(entry) = new_hek;
706 else if (hv == PL_strtab) {
707 /* PL_strtab is usually the only hash without HvSHAREKEYS,
708 so putting this test here is cheap */
709 if (flags & HVhek_FREEKEY)
711 Perl_croak(aTHX_ S_strtab_error,
712 action & HV_FETCH_LVALUE ? "fetch" : "store");
715 HeKFLAGS(entry) = masked_flags;
716 if (masked_flags & HVhek_ENABLEHVKFLAGS)
719 if (HeVAL(entry) == &PL_sv_placeholder) {
720 /* yes, can store into placeholder slot */
721 if (action & HV_FETCH_LVALUE) {
723 /* This preserves behaviour with the old hv_fetch
724 implementation which at this point would bail out
725 with a break; (at "if we find a placeholder, we
726 pretend we haven't found anything")
728 That break mean that if a placeholder were found, it
729 caused a call into hv_store, which in turn would
730 check magic, and if there is no magic end up pretty
731 much back at this point (in hv_store's code). */
734 /* LVAL fetch which actaully needs a store. */
736 HvPLACEHOLDERS(hv)--;
739 if (val != &PL_sv_placeholder)
740 HvPLACEHOLDERS(hv)--;
743 } else if (action & HV_FETCH_ISSTORE) {
744 SvREFCNT_dec(HeVAL(entry));
747 } else if (HeVAL(entry) == &PL_sv_placeholder) {
748 /* if we find a placeholder, we pretend we haven't found
752 if (flags & HVhek_FREEKEY)
756 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
757 if (!(action & HV_FETCH_ISSTORE)
758 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
760 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
762 sv = newSVpvn(env,len);
764 return hv_common(hv, keysv, key, klen, flags,
765 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, sv, hash);
770 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
771 hv_notallowed(flags, key, klen,
772 "Attempt to access disallowed key '%"SVf"' in"
773 " a restricted hash");
775 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
776 /* Not doing some form of store, so return failure. */
777 if (flags & HVhek_FREEKEY)
781 if (action & HV_FETCH_LVALUE) {
784 /* At this point the old hv_fetch code would call to hv_store,
785 which in turn might do some tied magic. So we need to make that
786 magic check happen. */
787 /* gonna assign to this, so it better be there */
788 /* If a fetch-as-store fails on the fetch, then the action is to
789 recurse once into "hv_store". If we didn't do this, then that
790 recursive call would call the key conversion routine again.
791 However, as we replace the original key with the converted
792 key, this would result in a double conversion, which would show
793 up as a bug if the conversion routine is not idempotent. */
794 return hv_common(hv, keysv, key, klen, flags,
795 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, val, hash);
796 /* XXX Surely that could leak if the fetch-was-store fails?
797 Just like the hv_fetch. */
801 /* Welcome to hv_store... */
804 /* Not sure if we can get here. I think the only case of oentry being
805 NULL is for %ENV with dynamic env fetch. But that should disappear
806 with magic in the previous code. */
809 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
811 HvARRAY(hv) = (HE**)array;
814 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
817 /* share_hek_flags will do the free for us. This might be considered
820 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
821 else if (hv == PL_strtab) {
822 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
823 this test here is cheap */
824 if (flags & HVhek_FREEKEY)
826 Perl_croak(aTHX_ S_strtab_error,
827 action & HV_FETCH_LVALUE ? "fetch" : "store");
829 else /* gotta do the real thing */
830 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
832 HeNEXT(entry) = *oentry;
835 if (val == &PL_sv_placeholder)
836 HvPLACEHOLDERS(hv)++;
837 if (masked_flags & HVhek_ENABLEHVKFLAGS)
841 const HE *counter = HeNEXT(entry);
843 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
844 if (!counter) { /* initial entry? */
845 xhv->xhv_fill++; /* HvFILL(hv)++ */
846 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
848 } else if(!HvREHASH(hv)) {
851 while ((counter = HeNEXT(counter)))
854 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
855 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
856 bucket splits on a rehashed hash, as we're not going to
857 split it again, and if someone is lucky (evil) enough to
858 get all the keys in one list they could exhaust our memory
859 as we repeatedly double the number of buckets on every
860 entry. Linear search feels a less worse thing to do. */
870 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
872 const MAGIC *mg = SvMAGIC(hv);
876 if (isUPPER(mg->mg_type)) {
878 if (mg->mg_type == PERL_MAGIC_tied) {
879 *needs_store = FALSE;
880 return; /* We've set all there is to set. */
883 mg = mg->mg_moremagic;
888 =for apidoc hv_scalar
890 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
896 Perl_hv_scalar(pTHX_ HV *hv)
900 if (SvRMAGICAL(hv)) {
901 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
903 return magic_scalarpack(hv, mg);
908 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
909 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
917 =for apidoc hv_delete
919 Deletes a key/value pair in the hash. The value SV is removed from the
920 hash and returned to the caller. The C<klen> is the length of the key.
921 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
928 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
935 k_flags = HVhek_UTF8;
940 return (SV *) hv_common(hv, NULL, key, klen, k_flags, flags | HV_DELETE,
945 =for apidoc hv_delete_ent
947 Deletes a key/value pair in the hash. The value SV is removed from the
948 hash and returned to the caller. The C<flags> value will normally be zero;
949 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
950 precomputed hash value, or 0 to ask for it to be computed.
956 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
957 int k_flags, I32 d_flags, U32 hash)
962 register HE **oentry;
963 HE *const *first_entry;
964 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
967 if (SvRMAGICAL(hv)) {
970 hv_magic_check (hv, &needs_copy, &needs_store);
974 entry = hv_common(hv, keysv, key, klen, k_flags & ~HVhek_FREEKEY,
975 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY, NULL,
977 sv = entry ? HeVAL(entry) : NULL;
983 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
984 /* No longer an element */
985 sv_unmagic(sv, PERL_MAGIC_tiedelem);
988 return NULL; /* element cannot be deleted */
990 #ifdef ENV_IS_CASELESS
991 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
992 /* XXX This code isn't UTF8 clean. */
993 keysv = sv_2mortal(newSVpvn(key,klen));
994 if (k_flags & HVhek_FREEKEY) {
997 key = strupr(SvPVX(keysv));
1006 xhv = (XPVHV*)SvANY(hv);
1011 const char * const keysave = key;
1012 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1015 k_flags |= HVhek_UTF8;
1017 k_flags &= ~HVhek_UTF8;
1018 if (key != keysave) {
1019 if (k_flags & HVhek_FREEKEY) {
1020 /* This shouldn't happen if our caller does what we expect,
1021 but strictly the API allows it. */
1024 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1026 HvHASKFLAGS_on((SV*)hv);
1030 PERL_HASH_INTERNAL(hash, key, klen);
1032 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1033 hash = SvSHARED_HASH(keysv);
1035 PERL_HASH(hash, key, klen);
1039 masked_flags = (k_flags & HVhek_MASK);
1041 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1043 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1045 if (HeHASH(entry) != hash) /* strings can't be equal */
1047 if (HeKLEN(entry) != (I32)klen)
1049 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1051 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1054 if (hv == PL_strtab) {
1055 if (k_flags & HVhek_FREEKEY)
1057 Perl_croak(aTHX_ S_strtab_error, "delete");
1060 /* if placeholder is here, it's already been deleted.... */
1061 if (HeVAL(entry) == &PL_sv_placeholder) {
1062 if (k_flags & HVhek_FREEKEY)
1066 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1067 hv_notallowed(k_flags, key, klen,
1068 "Attempt to delete readonly key '%"SVf"' from"
1069 " a restricted hash");
1071 if (k_flags & HVhek_FREEKEY)
1074 if (d_flags & G_DISCARD)
1077 sv = sv_2mortal(HeVAL(entry));
1078 HeVAL(entry) = &PL_sv_placeholder;
1082 * If a restricted hash, rather than really deleting the entry, put
1083 * a placeholder there. This marks the key as being "approved", so
1084 * we can still access via not-really-existing key without raising
1087 if (SvREADONLY(hv)) {
1088 SvREFCNT_dec(HeVAL(entry));
1089 HeVAL(entry) = &PL_sv_placeholder;
1090 /* We'll be saving this slot, so the number of allocated keys
1091 * doesn't go down, but the number placeholders goes up */
1092 HvPLACEHOLDERS(hv)++;
1094 *oentry = HeNEXT(entry);
1096 xhv->xhv_fill--; /* HvFILL(hv)-- */
1098 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1101 hv_free_ent(hv, entry);
1102 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1103 if (xhv->xhv_keys == 0)
1104 HvHASKFLAGS_off(hv);
1108 if (SvREADONLY(hv)) {
1109 hv_notallowed(k_flags, key, klen,
1110 "Attempt to delete disallowed key '%"SVf"' from"
1111 " a restricted hash");
1114 if (k_flags & HVhek_FREEKEY)
1120 S_hsplit(pTHX_ HV *hv)
1123 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1124 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1125 register I32 newsize = oldsize * 2;
1127 char *a = (char*) HvARRAY(hv);
1129 register HE **oentry;
1130 int longest_chain = 0;
1133 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1134 (void*)hv, (int) oldsize);*/
1136 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1137 /* Can make this clear any placeholders first for non-restricted hashes,
1138 even though Storable rebuilds restricted hashes by putting in all the
1139 placeholders (first) before turning on the readonly flag, because
1140 Storable always pre-splits the hash. */
1141 hv_clear_placeholders(hv);
1145 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1146 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1147 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1153 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1156 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1157 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1162 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1164 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1166 if (oldsize >= 64) {
1167 offer_nice_chunk(HvARRAY(hv),
1168 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1169 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1172 Safefree(HvARRAY(hv));
1176 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1177 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1178 HvARRAY(hv) = (HE**) a;
1181 for (i=0; i<oldsize; i++,aep++) {
1182 int left_length = 0;
1183 int right_length = 0;
1187 if (!*aep) /* non-existent */
1190 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1191 if ((HeHASH(entry) & newsize) != (U32)i) {
1192 *oentry = HeNEXT(entry);
1193 HeNEXT(entry) = *bep;
1195 xhv->xhv_fill++; /* HvFILL(hv)++ */
1201 oentry = &HeNEXT(entry);
1205 if (!*aep) /* everything moved */
1206 xhv->xhv_fill--; /* HvFILL(hv)-- */
1207 /* I think we don't actually need to keep track of the longest length,
1208 merely flag if anything is too long. But for the moment while
1209 developing this code I'll track it. */
1210 if (left_length > longest_chain)
1211 longest_chain = left_length;
1212 if (right_length > longest_chain)
1213 longest_chain = right_length;
1217 /* Pick your policy for "hashing isn't working" here: */
1218 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1223 if (hv == PL_strtab) {
1224 /* Urg. Someone is doing something nasty to the string table.
1229 /* Awooga. Awooga. Pathological data. */
1230 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1231 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1234 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1235 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1237 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1240 was_shared = HvSHAREKEYS(hv);
1243 HvSHAREKEYS_off(hv);
1248 for (i=0; i<newsize; i++,aep++) {
1249 register HE *entry = *aep;
1251 /* We're going to trash this HE's next pointer when we chain it
1252 into the new hash below, so store where we go next. */
1253 HE * const next = HeNEXT(entry);
1258 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1263 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1264 hash, HeKFLAGS(entry));
1265 unshare_hek (HeKEY_hek(entry));
1266 HeKEY_hek(entry) = new_hek;
1268 /* Not shared, so simply write the new hash in. */
1269 HeHASH(entry) = hash;
1271 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1272 HEK_REHASH_on(HeKEY_hek(entry));
1273 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1275 /* Copy oentry to the correct new chain. */
1276 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1278 xhv->xhv_fill++; /* HvFILL(hv)++ */
1279 HeNEXT(entry) = *bep;
1285 Safefree (HvARRAY(hv));
1286 HvARRAY(hv) = (HE **)a;
1290 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1293 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1294 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1295 register I32 newsize;
1300 register HE **oentry;
1302 newsize = (I32) newmax; /* possible truncation here */
1303 if (newsize != newmax || newmax <= oldsize)
1305 while ((newsize & (1 + ~newsize)) != newsize) {
1306 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1308 if (newsize < newmax)
1310 if (newsize < newmax)
1311 return; /* overflow detection */
1313 a = (char *) HvARRAY(hv);
1316 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1317 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1318 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1324 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1327 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1328 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1333 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1335 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1337 if (oldsize >= 64) {
1338 offer_nice_chunk(HvARRAY(hv),
1339 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1340 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1343 Safefree(HvARRAY(hv));
1346 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1349 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1351 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1352 HvARRAY(hv) = (HE **) a;
1353 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1357 for (i=0; i<oldsize; i++,aep++) {
1358 if (!*aep) /* non-existent */
1360 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1361 register I32 j = (HeHASH(entry) & newsize);
1365 *oentry = HeNEXT(entry);
1366 if (!(HeNEXT(entry) = aep[j]))
1367 xhv->xhv_fill++; /* HvFILL(hv)++ */
1372 oentry = &HeNEXT(entry);
1374 if (!*aep) /* everything moved */
1375 xhv->xhv_fill--; /* HvFILL(hv)-- */
1382 Creates a new HV. The reference count is set to 1.
1390 register XPVHV* xhv;
1391 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1392 xhv = (XPVHV*)SvANY(hv);
1394 #ifndef NODEFAULT_SHAREKEYS
1395 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1398 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1399 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1404 Perl_newHVhv(pTHX_ HV *ohv)
1406 HV * const hv = newHV();
1407 STRLEN hv_max, hv_fill;
1409 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1411 hv_max = HvMAX(ohv);
1413 if (!SvMAGICAL((SV *)ohv)) {
1414 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1416 const bool shared = !!HvSHAREKEYS(ohv);
1417 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1419 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1422 /* In each bucket... */
1423 for (i = 0; i <= hv_max; i++) {
1425 HE *oent = oents[i];
1432 /* Copy the linked list of entries. */
1433 for (; oent; oent = HeNEXT(oent)) {
1434 const U32 hash = HeHASH(oent);
1435 const char * const key = HeKEY(oent);
1436 const STRLEN len = HeKLEN(oent);
1437 const int flags = HeKFLAGS(oent);
1438 HE * const ent = new_HE();
1440 HeVAL(ent) = newSVsv(HeVAL(oent));
1442 = shared ? share_hek_flags(key, len, hash, flags)
1443 : save_hek_flags(key, len, hash, flags);
1454 HvFILL(hv) = hv_fill;
1455 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1459 /* Iterate over ohv, copying keys and values one at a time. */
1461 const I32 riter = HvRITER_get(ohv);
1462 HE * const eiter = HvEITER_get(ohv);
1464 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1465 while (hv_max && hv_max + 1 >= hv_fill * 2)
1466 hv_max = hv_max / 2;
1470 while ((entry = hv_iternext_flags(ohv, 0))) {
1471 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1472 newSVsv(HeVAL(entry)), HeHASH(entry),
1475 HvRITER_set(ohv, riter);
1476 HvEITER_set(ohv, eiter);
1482 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1483 magic stays on it. */
1485 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1487 HV * const hv = newHV();
1490 if (ohv && (hv_fill = HvFILL(ohv))) {
1491 STRLEN hv_max = HvMAX(ohv);
1493 const I32 riter = HvRITER_get(ohv);
1494 HE * const eiter = HvEITER_get(ohv);
1496 while (hv_max && hv_max + 1 >= hv_fill * 2)
1497 hv_max = hv_max / 2;
1501 while ((entry = hv_iternext_flags(ohv, 0))) {
1502 SV *const sv = newSVsv(HeVAL(entry));
1503 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1504 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1505 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1506 sv, HeHASH(entry), HeKFLAGS(entry));
1508 HvRITER_set(ohv, riter);
1509 HvEITER_set(ohv, eiter);
1511 hv_magic(hv, NULL, PERL_MAGIC_hints);
1516 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1524 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1525 mro_method_changed_in(hv); /* deletion of method from stash */
1527 if (HeKLEN(entry) == HEf_SVKEY) {
1528 SvREFCNT_dec(HeKEY_sv(entry));
1529 Safefree(HeKEY_hek(entry));
1531 else if (HvSHAREKEYS(hv))
1532 unshare_hek(HeKEY_hek(entry));
1534 Safefree(HeKEY_hek(entry));
1539 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1544 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1545 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1546 if (HeKLEN(entry) == HEf_SVKEY) {
1547 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1549 hv_free_ent(hv, entry);
1553 =for apidoc hv_clear
1555 Clears a hash, making it empty.
1561 Perl_hv_clear(pTHX_ HV *hv)
1564 register XPVHV* xhv;
1568 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1570 xhv = (XPVHV*)SvANY(hv);
1572 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1573 /* restricted hash: convert all keys to placeholders */
1575 for (i = 0; i <= xhv->xhv_max; i++) {
1576 HE *entry = (HvARRAY(hv))[i];
1577 for (; entry; entry = HeNEXT(entry)) {
1578 /* not already placeholder */
1579 if (HeVAL(entry) != &PL_sv_placeholder) {
1580 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1581 SV* const keysv = hv_iterkeysv(entry);
1583 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1586 SvREFCNT_dec(HeVAL(entry));
1587 HeVAL(entry) = &PL_sv_placeholder;
1588 HvPLACEHOLDERS(hv)++;
1596 HvPLACEHOLDERS_set(hv, 0);
1598 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1603 HvHASKFLAGS_off(hv);
1608 mro_isa_changed_in(hv);
1609 HvEITER_set(hv, NULL);
1614 =for apidoc hv_clear_placeholders
1616 Clears any placeholders from a hash. If a restricted hash has any of its keys
1617 marked as readonly and the key is subsequently deleted, the key is not actually
1618 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1619 it so it will be ignored by future operations such as iterating over the hash,
1620 but will still allow the hash to have a value reassigned to the key at some
1621 future point. This function clears any such placeholder keys from the hash.
1622 See Hash::Util::lock_keys() for an example of its use.
1628 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1631 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1634 clear_placeholders(hv, items);
1638 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1648 /* Loop down the linked list heads */
1650 HE **oentry = &(HvARRAY(hv))[i];
1653 while ((entry = *oentry)) {
1654 if (HeVAL(entry) == &PL_sv_placeholder) {
1655 *oentry = HeNEXT(entry);
1656 if (first && !*oentry)
1657 HvFILL(hv)--; /* This linked list is now empty. */
1658 if (entry == HvEITER_get(hv))
1661 hv_free_ent(hv, entry);
1665 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1666 if (HvKEYS(hv) == 0)
1667 HvHASKFLAGS_off(hv);
1668 HvPLACEHOLDERS_set(hv, 0);
1672 oentry = &HeNEXT(entry);
1677 /* You can't get here, hence assertion should always fail. */
1678 assert (items == 0);
1683 S_hfreeentries(pTHX_ HV *hv)
1685 /* This is the array that we're going to restore */
1686 HE **const orig_array = HvARRAY(hv);
1694 /* If the hash is actually a symbol table with a name, look after the
1696 struct xpvhv_aux *iter = HvAUX(hv);
1698 name = iter->xhv_name;
1699 iter->xhv_name = NULL;
1704 /* orig_array remains unchanged throughout the loop. If after freeing all
1705 the entries it turns out that one of the little blighters has triggered
1706 an action that has caused HvARRAY to be re-allocated, then we set
1707 array to the new HvARRAY, and try again. */
1710 /* This is the one we're going to try to empty. First time round
1711 it's the original array. (Hopefully there will only be 1 time
1713 HE ** const array = HvARRAY(hv);
1716 /* Because we have taken xhv_name out, the only allocated pointer
1717 in the aux structure that might exist is the backreference array.
1722 struct mro_meta *meta;
1723 struct xpvhv_aux *iter = HvAUX(hv);
1724 /* If there are weak references to this HV, we need to avoid
1725 freeing them up here. In particular we need to keep the AV
1726 visible as what we're deleting might well have weak references
1727 back to this HV, so the for loop below may well trigger
1728 the removal of backreferences from this array. */
1730 if (iter->xhv_backreferences) {
1731 /* So donate them to regular backref magic to keep them safe.
1732 The sv_magic will increase the reference count of the AV,
1733 so we need to drop it first. */
1734 SvREFCNT_dec(iter->xhv_backreferences);
1735 if (AvFILLp(iter->xhv_backreferences) == -1) {
1736 /* Turns out that the array is empty. Just free it. */
1737 SvREFCNT_dec(iter->xhv_backreferences);
1740 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1741 PERL_MAGIC_backref, NULL, 0);
1743 iter->xhv_backreferences = NULL;
1746 entry = iter->xhv_eiter; /* HvEITER(hv) */
1747 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1749 hv_free_ent(hv, entry);
1751 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1752 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1754 if((meta = iter->xhv_mro_meta)) {
1755 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1756 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1757 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1759 iter->xhv_mro_meta = NULL;
1762 /* There are now no allocated pointers in the aux structure. */
1764 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1765 /* What aux structure? */
1768 /* make everyone else think the array is empty, so that the destructors
1769 * called for freed entries can't recusively mess with us */
1772 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1776 /* Loop down the linked list heads */
1777 HE *entry = array[i];
1780 register HE * const oentry = entry;
1781 entry = HeNEXT(entry);
1782 hv_free_ent(hv, oentry);
1786 /* As there are no allocated pointers in the aux structure, it's now
1787 safe to free the array we just cleaned up, if it's not the one we're
1788 going to put back. */
1789 if (array != orig_array) {
1794 /* Good. No-one added anything this time round. */
1799 /* Someone attempted to iterate or set the hash name while we had
1800 the array set to 0. We'll catch backferences on the next time
1801 round the while loop. */
1802 assert(HvARRAY(hv));
1804 if (HvAUX(hv)->xhv_name) {
1805 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1809 if (--attempts == 0) {
1810 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1814 HvARRAY(hv) = orig_array;
1816 /* If the hash was actually a symbol table, put the name back. */
1818 /* We have restored the original array. If name is non-NULL, then
1819 the original array had an aux structure at the end. So this is
1821 SvFLAGS(hv) |= SVf_OOK;
1822 HvAUX(hv)->xhv_name = name;
1827 =for apidoc hv_undef
1835 Perl_hv_undef(pTHX_ HV *hv)
1838 register XPVHV* xhv;
1843 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1844 xhv = (XPVHV*)SvANY(hv);
1846 if ((name = HvNAME_get(hv)) && !PL_dirty)
1847 mro_isa_changed_in(hv);
1852 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1853 hv_name_set(hv, NULL, 0, 0);
1855 SvFLAGS(hv) &= ~SVf_OOK;
1856 Safefree(HvARRAY(hv));
1857 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1859 HvPLACEHOLDERS_set(hv, 0);
1865 static struct xpvhv_aux*
1866 S_hv_auxinit(HV *hv) {
1867 struct xpvhv_aux *iter;
1871 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1872 + sizeof(struct xpvhv_aux), char);
1874 array = (char *) HvARRAY(hv);
1875 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1876 + sizeof(struct xpvhv_aux), char);
1878 HvARRAY(hv) = (HE**) array;
1879 /* SvOOK_on(hv) attacks the IV flags. */
1880 SvFLAGS(hv) |= SVf_OOK;
1883 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1884 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1886 iter->xhv_backreferences = 0;
1887 iter->xhv_mro_meta = NULL;
1892 =for apidoc hv_iterinit
1894 Prepares a starting point to traverse a hash table. Returns the number of
1895 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1896 currently only meaningful for hashes without tie magic.
1898 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1899 hash buckets that happen to be in use. If you still need that esoteric
1900 value, you can get it through the macro C<HvFILL(tb)>.
1907 Perl_hv_iterinit(pTHX_ HV *hv)
1910 Perl_croak(aTHX_ "Bad hash");
1913 struct xpvhv_aux * const iter = HvAUX(hv);
1914 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1915 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1917 hv_free_ent(hv, entry);
1919 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1920 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1925 /* used to be xhv->xhv_fill before 5.004_65 */
1926 return HvTOTALKEYS(hv);
1930 Perl_hv_riter_p(pTHX_ HV *hv) {
1931 struct xpvhv_aux *iter;
1934 Perl_croak(aTHX_ "Bad hash");
1936 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1937 return &(iter->xhv_riter);
1941 Perl_hv_eiter_p(pTHX_ HV *hv) {
1942 struct xpvhv_aux *iter;
1945 Perl_croak(aTHX_ "Bad hash");
1947 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1948 return &(iter->xhv_eiter);
1952 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1953 struct xpvhv_aux *iter;
1956 Perl_croak(aTHX_ "Bad hash");
1964 iter = hv_auxinit(hv);
1966 iter->xhv_riter = riter;
1970 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1971 struct xpvhv_aux *iter;
1974 Perl_croak(aTHX_ "Bad hash");
1979 /* 0 is the default so don't go malloc()ing a new structure just to
1984 iter = hv_auxinit(hv);
1986 iter->xhv_eiter = eiter;
1990 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1993 struct xpvhv_aux *iter;
1996 PERL_UNUSED_ARG(flags);
1999 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2003 if (iter->xhv_name) {
2004 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2010 iter = hv_auxinit(hv);
2012 PERL_HASH(hash, name, len);
2013 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2017 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2018 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2019 PERL_UNUSED_CONTEXT;
2020 return &(iter->xhv_backreferences);
2024 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2030 av = HvAUX(hv)->xhv_backreferences;
2033 HvAUX(hv)->xhv_backreferences = 0;
2034 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2039 hv_iternext is implemented as a macro in hv.h
2041 =for apidoc hv_iternext
2043 Returns entries from a hash iterator. See C<hv_iterinit>.
2045 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2046 iterator currently points to, without losing your place or invalidating your
2047 iterator. Note that in this case the current entry is deleted from the hash
2048 with your iterator holding the last reference to it. Your iterator is flagged
2049 to free the entry on the next call to C<hv_iternext>, so you must not discard
2050 your iterator immediately else the entry will leak - call C<hv_iternext> to
2051 trigger the resource deallocation.
2053 =for apidoc hv_iternext_flags
2055 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2056 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2057 set the placeholders keys (for restricted hashes) will be returned in addition
2058 to normal keys. By default placeholders are automatically skipped over.
2059 Currently a placeholder is implemented with a value that is
2060 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2061 restricted hashes may change, and the implementation currently is
2062 insufficiently abstracted for any change to be tidy.
2068 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2071 register XPVHV* xhv;
2075 struct xpvhv_aux *iter;
2078 Perl_croak(aTHX_ "Bad hash");
2080 xhv = (XPVHV*)SvANY(hv);
2083 /* Too many things (well, pp_each at least) merrily assume that you can
2084 call iv_iternext without calling hv_iterinit, so we'll have to deal
2090 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2091 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2092 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2093 SV * const key = sv_newmortal();
2095 sv_setsv(key, HeSVKEY_force(entry));
2096 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2102 /* one HE per MAGICAL hash */
2103 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2105 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2107 HeKEY_hek(entry) = hek;
2108 HeKLEN(entry) = HEf_SVKEY;
2110 magic_nextpack((SV*) hv,mg,key);
2112 /* force key to stay around until next time */
2113 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2114 return entry; /* beware, hent_val is not set */
2117 SvREFCNT_dec(HeVAL(entry));
2118 Safefree(HeKEY_hek(entry));
2120 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2124 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2125 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2128 /* The prime_env_iter() on VMS just loaded up new hash values
2129 * so the iteration count needs to be reset back to the beginning
2133 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2138 /* hv_iterint now ensures this. */
2139 assert (HvARRAY(hv));
2141 /* At start of hash, entry is NULL. */
2144 entry = HeNEXT(entry);
2145 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2147 * Skip past any placeholders -- don't want to include them in
2150 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2151 entry = HeNEXT(entry);
2156 /* OK. Come to the end of the current list. Grab the next one. */
2158 iter->xhv_riter++; /* HvRITER(hv)++ */
2159 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2160 /* There is no next one. End of the hash. */
2161 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2164 entry = (HvARRAY(hv))[iter->xhv_riter];
2166 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2167 /* If we have an entry, but it's a placeholder, don't count it.
2169 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2170 entry = HeNEXT(entry);
2172 /* Will loop again if this linked list starts NULL
2173 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2174 or if we run through it and find only placeholders. */
2177 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2179 hv_free_ent(hv, oldentry);
2182 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2183 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2185 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2190 =for apidoc hv_iterkey
2192 Returns the key from the current position of the hash iterator. See
2199 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2201 if (HeKLEN(entry) == HEf_SVKEY) {
2203 char * const p = SvPV(HeKEY_sv(entry), len);
2208 *retlen = HeKLEN(entry);
2209 return HeKEY(entry);
2213 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2215 =for apidoc hv_iterkeysv
2217 Returns the key as an C<SV*> from the current position of the hash
2218 iterator. The return value will always be a mortal copy of the key. Also
2225 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2227 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2231 =for apidoc hv_iterval
2233 Returns the value from the current position of the hash iterator. See
2240 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2242 if (SvRMAGICAL(hv)) {
2243 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2244 SV* const sv = sv_newmortal();
2245 if (HeKLEN(entry) == HEf_SVKEY)
2246 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2248 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2252 return HeVAL(entry);
2256 =for apidoc hv_iternextsv
2258 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2265 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2267 HE * const he = hv_iternext_flags(hv, 0);
2271 *key = hv_iterkey(he, retlen);
2272 return hv_iterval(hv, he);
2279 =for apidoc hv_magic
2281 Adds magic to a hash. See C<sv_magic>.
2286 /* possibly free a shared string if no one has access to it
2287 * len and hash must both be valid for str.
2290 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2292 unshare_hek_or_pvn (NULL, str, len, hash);
2297 Perl_unshare_hek(pTHX_ HEK *hek)
2300 unshare_hek_or_pvn(hek, NULL, 0, 0);
2303 /* possibly free a shared string if no one has access to it
2304 hek if non-NULL takes priority over the other 3, else str, len and hash
2305 are used. If so, len and hash must both be valid for str.
2308 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2311 register XPVHV* xhv;
2313 register HE **oentry;
2315 bool is_utf8 = FALSE;
2317 const char * const save = str;
2318 struct shared_he *he = NULL;
2321 /* Find the shared he which is just before us in memory. */
2322 he = (struct shared_he *)(((char *)hek)
2323 - STRUCT_OFFSET(struct shared_he,
2326 /* Assert that the caller passed us a genuine (or at least consistent)
2328 assert (he->shared_he_he.hent_hek == hek);
2331 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2332 --he->shared_he_he.he_valu.hent_refcount;
2333 UNLOCK_STRTAB_MUTEX;
2336 UNLOCK_STRTAB_MUTEX;
2338 hash = HEK_HASH(hek);
2339 } else if (len < 0) {
2340 STRLEN tmplen = -len;
2342 /* See the note in hv_fetch(). --jhi */
2343 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2346 k_flags = HVhek_UTF8;
2348 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2351 /* what follows was the moral equivalent of:
2352 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2354 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2356 xhv = (XPVHV*)SvANY(PL_strtab);
2357 /* assert(xhv_array != 0) */
2359 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2361 const HE *const he_he = &(he->shared_he_he);
2362 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2367 const int flags_masked = k_flags & HVhek_MASK;
2368 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2369 if (HeHASH(entry) != hash) /* strings can't be equal */
2371 if (HeKLEN(entry) != len)
2373 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2375 if (HeKFLAGS(entry) != flags_masked)
2382 if (--entry->he_valu.hent_refcount == 0) {
2383 *oentry = HeNEXT(entry);
2385 /* There are now no entries in our slot. */
2386 xhv->xhv_fill--; /* HvFILL(hv)-- */
2389 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2393 UNLOCK_STRTAB_MUTEX;
2394 if (!entry && ckWARN_d(WARN_INTERNAL))
2395 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2396 "Attempt to free non-existent shared string '%s'%s"
2398 hek ? HEK_KEY(hek) : str,
2399 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2400 if (k_flags & HVhek_FREEKEY)
2404 /* get a (constant) string ptr from the global string table
2405 * string will get added if it is not already there.
2406 * len and hash must both be valid for str.
2409 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2411 bool is_utf8 = FALSE;
2413 const char * const save = str;
2416 STRLEN tmplen = -len;
2418 /* See the note in hv_fetch(). --jhi */
2419 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2421 /* If we were able to downgrade here, then than means that we were passed
2422 in a key which only had chars 0-255, but was utf8 encoded. */
2425 /* If we found we were able to downgrade the string to bytes, then
2426 we should flag that it needs upgrading on keys or each. Also flag
2427 that we need share_hek_flags to free the string. */
2429 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2432 return share_hek_flags (str, len, hash, flags);
2436 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2440 const int flags_masked = flags & HVhek_MASK;
2441 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2443 /* what follows is the moral equivalent of:
2445 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2446 hv_store(PL_strtab, str, len, NULL, hash);
2448 Can't rehash the shared string table, so not sure if it's worth
2449 counting the number of entries in the linked list
2451 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2452 /* assert(xhv_array != 0) */
2454 entry = (HvARRAY(PL_strtab))[hindex];
2455 for (;entry; entry = HeNEXT(entry)) {
2456 if (HeHASH(entry) != hash) /* strings can't be equal */
2458 if (HeKLEN(entry) != len)
2460 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2462 if (HeKFLAGS(entry) != flags_masked)
2468 /* What used to be head of the list.
2469 If this is NULL, then we're the first entry for this slot, which
2470 means we need to increate fill. */
2471 struct shared_he *new_entry;
2474 HE **const head = &HvARRAY(PL_strtab)[hindex];
2475 HE *const next = *head;
2477 /* We don't actually store a HE from the arena and a regular HEK.
2478 Instead we allocate one chunk of memory big enough for both,
2479 and put the HEK straight after the HE. This way we can find the
2480 HEK directly from the HE.
2483 Newx(k, STRUCT_OFFSET(struct shared_he,
2484 shared_he_hek.hek_key[0]) + len + 2, char);
2485 new_entry = (struct shared_he *)k;
2486 entry = &(new_entry->shared_he_he);
2487 hek = &(new_entry->shared_he_hek);
2489 Copy(str, HEK_KEY(hek), len, char);
2490 HEK_KEY(hek)[len] = 0;
2492 HEK_HASH(hek) = hash;
2493 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2495 /* Still "point" to the HEK, so that other code need not know what
2497 HeKEY_hek(entry) = hek;
2498 entry->he_valu.hent_refcount = 0;
2499 HeNEXT(entry) = next;
2502 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2503 if (!next) { /* initial entry? */
2504 xhv->xhv_fill++; /* HvFILL(hv)++ */
2505 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2510 ++entry->he_valu.hent_refcount;
2511 UNLOCK_STRTAB_MUTEX;
2513 if (flags & HVhek_FREEKEY)
2516 return HeKEY_hek(entry);
2520 Perl_hv_placeholders_p(pTHX_ HV *hv)
2523 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2526 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2529 Perl_die(aTHX_ "panic: hv_placeholders_p");
2532 return &(mg->mg_len);
2537 Perl_hv_placeholders_get(pTHX_ HV *hv)
2540 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2542 return mg ? mg->mg_len : 0;
2546 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2549 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2554 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2555 Perl_die(aTHX_ "panic: hv_placeholders_set");
2557 /* else we don't need to add magic to record 0 placeholders. */
2561 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2565 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2570 value = &PL_sv_placeholder;
2573 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2576 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2579 case HVrhek_PV_UTF8:
2580 /* Create a string SV that directly points to the bytes in our
2582 value = newSV_type(SVt_PV);
2583 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2584 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2585 /* This stops anything trying to free it */
2586 SvLEN_set(value, 0);
2588 SvREADONLY_on(value);
2589 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2593 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2594 he->refcounted_he_data[0]);
2600 =for apidoc refcounted_he_chain_2hv
2602 Generates and returns a C<HV *> by walking up the tree starting at the passed
2603 in C<struct refcounted_he *>.
2608 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2612 U32 placeholders = 0;
2613 /* We could chase the chain once to get an idea of the number of keys,
2614 and call ksplit. But for now we'll make a potentially inefficient
2615 hash with only 8 entries in its array. */
2616 const U32 max = HvMAX(hv);
2620 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2621 HvARRAY(hv) = (HE**)array;
2626 U32 hash = chain->refcounted_he_hash;
2628 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2630 HE **oentry = &((HvARRAY(hv))[hash & max]);
2631 HE *entry = *oentry;
2634 for (; entry; entry = HeNEXT(entry)) {
2635 if (HeHASH(entry) == hash) {
2636 /* We might have a duplicate key here. If so, entry is older
2637 than the key we've already put in the hash, so if they are
2638 the same, skip adding entry. */
2640 const STRLEN klen = HeKLEN(entry);
2641 const char *const key = HeKEY(entry);
2642 if (klen == chain->refcounted_he_keylen
2643 && (!!HeKUTF8(entry)
2644 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2645 && memEQ(key, REF_HE_KEY(chain), klen))
2648 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2650 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2651 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2652 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2663 = share_hek_flags(REF_HE_KEY(chain),
2664 chain->refcounted_he_keylen,
2665 chain->refcounted_he_hash,
2666 (chain->refcounted_he_data[0]
2667 & (HVhek_UTF8|HVhek_WASUTF8)));
2669 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2671 value = refcounted_he_value(chain);
2672 if (value == &PL_sv_placeholder)
2674 HeVAL(entry) = value;
2676 /* Link it into the chain. */
2677 HeNEXT(entry) = *oentry;
2678 if (!HeNEXT(entry)) {
2679 /* initial entry. */
2687 chain = chain->refcounted_he_next;
2691 clear_placeholders(hv, placeholders);
2692 HvTOTALKEYS(hv) -= placeholders;
2695 /* We could check in the loop to see if we encounter any keys with key
2696 flags, but it's probably not worth it, as this per-hash flag is only
2697 really meant as an optimisation for things like Storable. */
2699 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2705 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2706 const char *key, STRLEN klen, int flags, U32 hash)
2709 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2710 of your key has to exactly match that which is stored. */
2711 SV *value = &PL_sv_placeholder;
2715 if (flags & HVhek_FREEKEY)
2717 key = SvPV_const(keysv, klen);
2719 is_utf8 = (SvUTF8(keysv) != 0);
2721 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2725 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2726 hash = SvSHARED_HASH(keysv);
2728 PERL_HASH(hash, key, klen);
2732 for (; chain; chain = chain->refcounted_he_next) {
2734 if (hash != chain->refcounted_he_hash)
2736 if (klen != chain->refcounted_he_keylen)
2738 if (memNE(REF_HE_KEY(chain),key,klen))
2740 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2743 if (hash != HEK_HASH(chain->refcounted_he_hek))
2745 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2747 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2749 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2753 value = sv_2mortal(refcounted_he_value(chain));
2757 if (flags & HVhek_FREEKEY)
2764 =for apidoc refcounted_he_new
2766 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2767 stored in a compact form, all references remain the property of the caller.
2768 The C<struct refcounted_he> is returned with a reference count of 1.
2773 struct refcounted_he *
2774 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2775 SV *const key, SV *const value) {
2777 struct refcounted_he *he;
2779 const char *key_p = SvPV_const(key, key_len);
2780 STRLEN value_len = 0;
2781 const char *value_p = NULL;
2786 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2789 value_type = HVrhek_PV;
2790 } else if (SvIOK(value)) {
2791 value_type = HVrhek_IV;
2792 } else if (value == &PL_sv_placeholder) {
2793 value_type = HVrhek_delete;
2794 } else if (!SvOK(value)) {
2795 value_type = HVrhek_undef;
2797 value_type = HVrhek_PV;
2800 if (value_type == HVrhek_PV) {
2801 value_p = SvPV_const(value, value_len);
2802 key_offset = value_len + 2;
2809 he = (struct refcounted_he*)
2810 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2814 he = (struct refcounted_he*)
2815 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2820 he->refcounted_he_next = parent;
2822 if (value_type == HVrhek_PV) {
2823 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2824 he->refcounted_he_val.refcounted_he_u_len = value_len;
2825 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2826 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2828 value_type = HVrhek_PV_UTF8;
2829 } else if (value_type == HVrhek_IV) {
2831 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2832 value_type = HVrhek_UV;
2834 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2840 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2841 As we're going to be building hash keys from this value in future,
2842 normalise it now. */
2843 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2844 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2846 PERL_HASH(hash, key_p, key_len);
2849 he->refcounted_he_hash = hash;
2850 he->refcounted_he_keylen = key_len;
2851 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2853 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2856 if (flags & HVhek_WASUTF8) {
2857 /* If it was downgraded from UTF-8, then the pointer returned from
2858 bytes_from_utf8 is an allocated pointer that we must free. */
2862 he->refcounted_he_data[0] = flags;
2863 he->refcounted_he_refcnt = 1;
2869 =for apidoc refcounted_he_free
2871 Decrements the reference count of the passed in C<struct refcounted_he *>
2872 by one. If the reference count reaches zero the structure's memory is freed,
2873 and C<refcounted_he_free> iterates onto the parent node.
2879 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2881 PERL_UNUSED_CONTEXT;
2884 struct refcounted_he *copy;
2888 new_count = --he->refcounted_he_refcnt;
2889 HINTS_REFCNT_UNLOCK;
2895 #ifndef USE_ITHREADS
2896 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2899 he = he->refcounted_he_next;
2900 PerlMemShared_free(copy);
2905 =for apidoc hv_assert
2907 Check that a hash is in an internally consistent state.
2915 Perl_hv_assert(pTHX_ HV *hv)
2920 int placeholders = 0;
2923 const I32 riter = HvRITER_get(hv);
2924 HE *eiter = HvEITER_get(hv);
2926 (void)hv_iterinit(hv);
2928 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2929 /* sanity check the values */
2930 if (HeVAL(entry) == &PL_sv_placeholder)
2934 /* sanity check the keys */
2935 if (HeSVKEY(entry)) {
2936 NOOP; /* Don't know what to check on SV keys. */
2937 } else if (HeKUTF8(entry)) {
2939 if (HeKWASUTF8(entry)) {
2940 PerlIO_printf(Perl_debug_log,
2941 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2942 (int) HeKLEN(entry), HeKEY(entry));
2945 } else if (HeKWASUTF8(entry))
2948 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2949 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2950 const int nhashkeys = HvUSEDKEYS(hv);
2951 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2953 if (nhashkeys != real) {
2954 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2957 if (nhashplaceholders != placeholders) {
2958 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2962 if (withflags && ! HvHASKFLAGS(hv)) {
2963 PerlIO_printf(Perl_debug_log,
2964 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2971 HvRITER_set(hv, riter); /* Restore hash iterator state */
2972 HvEITER_set(hv, eiter);
2979 * c-indentation-style: bsd
2981 * indent-tabs-mode: t
2984 * ex: set ts=8 sts=4 sw=4 noet: