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 = (HE *) 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 = (HE *) hv_common(hv, NULL, key, klen, flags,
267 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val,
269 return hek ? &HeVAL(hek) : NULL;
273 =for apidoc hv_store_ent
275 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
276 parameter is the precomputed hash value; if it is zero then Perl will
277 compute it. The return value is the new hash entry so created. It will be
278 NULL if the operation failed or if the value did not need to be actually
279 stored within the hash (as in the case of tied hashes). Otherwise the
280 contents of the return value can be accessed using the C<He?> macros
281 described here. Note that the caller is responsible for suitably
282 incrementing the reference count of C<val> before the call, and
283 decrementing it if the function returned NULL. Effectively a successful
284 hv_store_ent takes ownership of one reference to C<val>. This is
285 usually what you want; a newly created SV has a reference count of one, so
286 if all your code does is create SVs then store them in a hash, hv_store
287 will own the only reference to the new SV, and your code doesn't need to do
288 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
289 unlike C<val> it does not take ownership of it, so maintaining the correct
290 reference count on C<key> is entirely the caller's responsibility. hv_store
291 is not implemented as a call to hv_store_ent, and does not create a temporary
292 SV for the key, so if your key data is not already in SV form then use
293 hv_store in preference to hv_store_ent.
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
302 =for apidoc hv_exists
304 Returns a boolean indicating whether the specified hash key exists. The
305 C<klen> is the length of the key.
311 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
323 return hv_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
330 Returns the SV which corresponds to the specified key in the hash. The
331 C<klen> is the length of the key. If C<lval> is set then the fetch will be
332 part of a store. Check that the return value is non-null before
333 dereferencing it to an C<SV*>.
335 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
336 information on how to use this function on tied hashes.
342 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
355 hek = (HE *) hv_common(hv, NULL, key, klen, flags,
356 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE)
357 : HV_FETCH_JUST_SV, NULL, 0);
358 return hek ? &HeVAL(hek) : NULL;
362 =for apidoc hv_exists_ent
364 Returns a boolean indicating whether the specified hash key exists. C<hash>
365 can be a valid precomputed hash value, or 0 to ask for it to be
371 /* returns an HE * structure with the all fields set */
372 /* note that hent_val will be a mortal sv for MAGICAL hashes */
374 =for apidoc hv_fetch_ent
376 Returns the hash entry which corresponds to the specified key in the hash.
377 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
378 if you want the function to compute it. IF C<lval> is set then the fetch
379 will be part of a store. Make sure the return value is non-null before
380 accessing it. The return value when C<tb> is a tied hash is a pointer to a
381 static location, so be sure to make a copy of the structure if you need to
384 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
385 information on how to use this function on tied hashes.
391 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
392 int flags, int action, SV *val, register U32 hash)
404 if (SvTYPE(hv) == SVTYPEMASK)
407 assert(SvTYPE(hv) == SVt_PVHV);
409 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
411 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
412 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
413 if (uf->uf_set == NULL) {
414 SV* obj = mg->mg_obj;
417 keysv = sv_2mortal(newSVpvn(key, klen));
418 if (flags & HVhek_UTF8)
422 mg->mg_obj = keysv; /* pass key */
423 uf->uf_index = action; /* pass action */
424 magic_getuvar((SV*)hv, mg);
425 keysv = mg->mg_obj; /* may have changed */
428 /* If the key may have changed, then we need to invalidate
429 any passed-in computed hash value. */
435 if (flags & HVhek_FREEKEY)
437 key = SvPV_const(keysv, klen);
439 is_utf8 = (SvUTF8(keysv) != 0);
441 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
444 if (action & HV_DELETE) {
445 return (HE *) hv_delete_common(hv, keysv, key, klen,
446 flags | (is_utf8 ? HVhek_UTF8 : 0),
450 xhv = (XPVHV*)SvANY(hv);
452 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
453 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
455 /* XXX should be able to skimp on the HE/HEK here when
456 HV_FETCH_JUST_SV is true. */
458 keysv = newSVpvn(key, klen);
463 keysv = newSVsv(keysv);
466 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
468 /* grab a fake HE/HEK pair from the pool or make a new one */
469 entry = PL_hv_fetch_ent_mh;
471 PL_hv_fetch_ent_mh = HeNEXT(entry);
475 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
476 HeKEY_hek(entry) = (HEK*)k;
478 HeNEXT(entry) = NULL;
479 HeSVKEY_set(entry, keysv);
481 sv_upgrade(sv, SVt_PVLV);
483 /* so we can free entry when freeing sv */
484 LvTARG(sv) = (SV*)entry;
486 /* XXX remove at some point? */
487 if (flags & HVhek_FREEKEY)
492 #ifdef ENV_IS_CASELESS
493 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
495 for (i = 0; i < klen; ++i)
496 if (isLOWER(key[i])) {
497 /* Would be nice if we had a routine to do the
498 copy and upercase in a single pass through. */
499 const char * const nkey = strupr(savepvn(key,klen));
500 /* Note that this fetch is for nkey (the uppercased
501 key) whereas the store is for key (the original) */
502 void *result = hv_common(hv, NULL, nkey, klen,
503 HVhek_FREEKEY, /* free nkey */
504 0 /* non-LVAL fetch */
505 | HV_DISABLE_UVAR_XKEY,
507 0 /* compute hash */);
508 if (!entry && (action & HV_FETCH_LVALUE)) {
509 /* This call will free key if necessary.
510 Do it this way to encourage compiler to tail
512 result = hv_common(hv, keysv, key, klen, flags,
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 = (HE *) hv_common(hv, keysv, key, klen,
975 k_flags & ~HVhek_FREEKEY,
976 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
978 sv = entry ? HeVAL(entry) : NULL;
984 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
985 /* No longer an element */
986 sv_unmagic(sv, PERL_MAGIC_tiedelem);
989 return NULL; /* element cannot be deleted */
991 #ifdef ENV_IS_CASELESS
992 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
993 /* XXX This code isn't UTF8 clean. */
994 keysv = sv_2mortal(newSVpvn(key,klen));
995 if (k_flags & HVhek_FREEKEY) {
998 key = strupr(SvPVX(keysv));
1007 xhv = (XPVHV*)SvANY(hv);
1012 const char * const keysave = key;
1013 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1016 k_flags |= HVhek_UTF8;
1018 k_flags &= ~HVhek_UTF8;
1019 if (key != keysave) {
1020 if (k_flags & HVhek_FREEKEY) {
1021 /* This shouldn't happen if our caller does what we expect,
1022 but strictly the API allows it. */
1025 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1027 HvHASKFLAGS_on((SV*)hv);
1031 PERL_HASH_INTERNAL(hash, key, klen);
1033 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1034 hash = SvSHARED_HASH(keysv);
1036 PERL_HASH(hash, key, klen);
1040 masked_flags = (k_flags & HVhek_MASK);
1042 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1044 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1046 if (HeHASH(entry) != hash) /* strings can't be equal */
1048 if (HeKLEN(entry) != (I32)klen)
1050 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1052 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1055 if (hv == PL_strtab) {
1056 if (k_flags & HVhek_FREEKEY)
1058 Perl_croak(aTHX_ S_strtab_error, "delete");
1061 /* if placeholder is here, it's already been deleted.... */
1062 if (HeVAL(entry) == &PL_sv_placeholder) {
1063 if (k_flags & HVhek_FREEKEY)
1067 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1068 hv_notallowed(k_flags, key, klen,
1069 "Attempt to delete readonly key '%"SVf"' from"
1070 " a restricted hash");
1072 if (k_flags & HVhek_FREEKEY)
1075 if (d_flags & G_DISCARD)
1078 sv = sv_2mortal(HeVAL(entry));
1079 HeVAL(entry) = &PL_sv_placeholder;
1083 * If a restricted hash, rather than really deleting the entry, put
1084 * a placeholder there. This marks the key as being "approved", so
1085 * we can still access via not-really-existing key without raising
1088 if (SvREADONLY(hv)) {
1089 SvREFCNT_dec(HeVAL(entry));
1090 HeVAL(entry) = &PL_sv_placeholder;
1091 /* We'll be saving this slot, so the number of allocated keys
1092 * doesn't go down, but the number placeholders goes up */
1093 HvPLACEHOLDERS(hv)++;
1095 *oentry = HeNEXT(entry);
1097 xhv->xhv_fill--; /* HvFILL(hv)-- */
1099 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1102 hv_free_ent(hv, entry);
1103 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1104 if (xhv->xhv_keys == 0)
1105 HvHASKFLAGS_off(hv);
1109 if (SvREADONLY(hv)) {
1110 hv_notallowed(k_flags, key, klen,
1111 "Attempt to delete disallowed key '%"SVf"' from"
1112 " a restricted hash");
1115 if (k_flags & HVhek_FREEKEY)
1121 S_hsplit(pTHX_ HV *hv)
1124 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1125 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1126 register I32 newsize = oldsize * 2;
1128 char *a = (char*) HvARRAY(hv);
1130 register HE **oentry;
1131 int longest_chain = 0;
1134 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1135 (void*)hv, (int) oldsize);*/
1137 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1138 /* Can make this clear any placeholders first for non-restricted hashes,
1139 even though Storable rebuilds restricted hashes by putting in all the
1140 placeholders (first) before turning on the readonly flag, because
1141 Storable always pre-splits the hash. */
1142 hv_clear_placeholders(hv);
1146 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1147 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1148 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1154 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1157 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1158 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1163 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1165 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1167 if (oldsize >= 64) {
1168 offer_nice_chunk(HvARRAY(hv),
1169 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1170 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1173 Safefree(HvARRAY(hv));
1177 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1178 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1179 HvARRAY(hv) = (HE**) a;
1182 for (i=0; i<oldsize; i++,aep++) {
1183 int left_length = 0;
1184 int right_length = 0;
1188 if (!*aep) /* non-existent */
1191 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1192 if ((HeHASH(entry) & newsize) != (U32)i) {
1193 *oentry = HeNEXT(entry);
1194 HeNEXT(entry) = *bep;
1196 xhv->xhv_fill++; /* HvFILL(hv)++ */
1202 oentry = &HeNEXT(entry);
1206 if (!*aep) /* everything moved */
1207 xhv->xhv_fill--; /* HvFILL(hv)-- */
1208 /* I think we don't actually need to keep track of the longest length,
1209 merely flag if anything is too long. But for the moment while
1210 developing this code I'll track it. */
1211 if (left_length > longest_chain)
1212 longest_chain = left_length;
1213 if (right_length > longest_chain)
1214 longest_chain = right_length;
1218 /* Pick your policy for "hashing isn't working" here: */
1219 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1224 if (hv == PL_strtab) {
1225 /* Urg. Someone is doing something nasty to the string table.
1230 /* Awooga. Awooga. Pathological data. */
1231 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1232 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1235 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1236 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1238 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1241 was_shared = HvSHAREKEYS(hv);
1244 HvSHAREKEYS_off(hv);
1249 for (i=0; i<newsize; i++,aep++) {
1250 register HE *entry = *aep;
1252 /* We're going to trash this HE's next pointer when we chain it
1253 into the new hash below, so store where we go next. */
1254 HE * const next = HeNEXT(entry);
1259 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1264 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1265 hash, HeKFLAGS(entry));
1266 unshare_hek (HeKEY_hek(entry));
1267 HeKEY_hek(entry) = new_hek;
1269 /* Not shared, so simply write the new hash in. */
1270 HeHASH(entry) = hash;
1272 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1273 HEK_REHASH_on(HeKEY_hek(entry));
1274 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1276 /* Copy oentry to the correct new chain. */
1277 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1279 xhv->xhv_fill++; /* HvFILL(hv)++ */
1280 HeNEXT(entry) = *bep;
1286 Safefree (HvARRAY(hv));
1287 HvARRAY(hv) = (HE **)a;
1291 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1294 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1295 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1296 register I32 newsize;
1301 register HE **oentry;
1303 newsize = (I32) newmax; /* possible truncation here */
1304 if (newsize != newmax || newmax <= oldsize)
1306 while ((newsize & (1 + ~newsize)) != newsize) {
1307 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1309 if (newsize < newmax)
1311 if (newsize < newmax)
1312 return; /* overflow detection */
1314 a = (char *) HvARRAY(hv);
1317 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1318 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1319 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1325 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1328 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1329 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1334 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1336 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1338 if (oldsize >= 64) {
1339 offer_nice_chunk(HvARRAY(hv),
1340 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1341 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1344 Safefree(HvARRAY(hv));
1347 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1350 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1352 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1353 HvARRAY(hv) = (HE **) a;
1354 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1358 for (i=0; i<oldsize; i++,aep++) {
1359 if (!*aep) /* non-existent */
1361 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1362 register I32 j = (HeHASH(entry) & newsize);
1366 *oentry = HeNEXT(entry);
1367 if (!(HeNEXT(entry) = aep[j]))
1368 xhv->xhv_fill++; /* HvFILL(hv)++ */
1373 oentry = &HeNEXT(entry);
1375 if (!*aep) /* everything moved */
1376 xhv->xhv_fill--; /* HvFILL(hv)-- */
1383 Creates a new HV. The reference count is set to 1.
1391 register XPVHV* xhv;
1392 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1393 xhv = (XPVHV*)SvANY(hv);
1395 #ifndef NODEFAULT_SHAREKEYS
1396 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1399 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1400 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1405 Perl_newHVhv(pTHX_ HV *ohv)
1407 HV * const hv = newHV();
1408 STRLEN hv_max, hv_fill;
1410 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1412 hv_max = HvMAX(ohv);
1414 if (!SvMAGICAL((SV *)ohv)) {
1415 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1417 const bool shared = !!HvSHAREKEYS(ohv);
1418 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1420 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1423 /* In each bucket... */
1424 for (i = 0; i <= hv_max; i++) {
1426 HE *oent = oents[i];
1433 /* Copy the linked list of entries. */
1434 for (; oent; oent = HeNEXT(oent)) {
1435 const U32 hash = HeHASH(oent);
1436 const char * const key = HeKEY(oent);
1437 const STRLEN len = HeKLEN(oent);
1438 const int flags = HeKFLAGS(oent);
1439 HE * const ent = new_HE();
1441 HeVAL(ent) = newSVsv(HeVAL(oent));
1443 = shared ? share_hek_flags(key, len, hash, flags)
1444 : save_hek_flags(key, len, hash, flags);
1455 HvFILL(hv) = hv_fill;
1456 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1460 /* Iterate over ohv, copying keys and values one at a time. */
1462 const I32 riter = HvRITER_get(ohv);
1463 HE * const eiter = HvEITER_get(ohv);
1465 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1466 while (hv_max && hv_max + 1 >= hv_fill * 2)
1467 hv_max = hv_max / 2;
1471 while ((entry = hv_iternext_flags(ohv, 0))) {
1472 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1473 newSVsv(HeVAL(entry)), HeHASH(entry),
1476 HvRITER_set(ohv, riter);
1477 HvEITER_set(ohv, eiter);
1483 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1484 magic stays on it. */
1486 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1488 HV * const hv = newHV();
1491 if (ohv && (hv_fill = HvFILL(ohv))) {
1492 STRLEN hv_max = HvMAX(ohv);
1494 const I32 riter = HvRITER_get(ohv);
1495 HE * const eiter = HvEITER_get(ohv);
1497 while (hv_max && hv_max + 1 >= hv_fill * 2)
1498 hv_max = hv_max / 2;
1502 while ((entry = hv_iternext_flags(ohv, 0))) {
1503 SV *const sv = newSVsv(HeVAL(entry));
1504 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1505 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1506 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1507 sv, HeHASH(entry), HeKFLAGS(entry));
1509 HvRITER_set(ohv, riter);
1510 HvEITER_set(ohv, eiter);
1512 hv_magic(hv, NULL, PERL_MAGIC_hints);
1517 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1525 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1526 mro_method_changed_in(hv); /* deletion of method from stash */
1528 if (HeKLEN(entry) == HEf_SVKEY) {
1529 SvREFCNT_dec(HeKEY_sv(entry));
1530 Safefree(HeKEY_hek(entry));
1532 else if (HvSHAREKEYS(hv))
1533 unshare_hek(HeKEY_hek(entry));
1535 Safefree(HeKEY_hek(entry));
1540 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1545 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1546 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1547 if (HeKLEN(entry) == HEf_SVKEY) {
1548 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1550 hv_free_ent(hv, entry);
1554 =for apidoc hv_clear
1556 Clears a hash, making it empty.
1562 Perl_hv_clear(pTHX_ HV *hv)
1565 register XPVHV* xhv;
1569 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1571 xhv = (XPVHV*)SvANY(hv);
1573 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1574 /* restricted hash: convert all keys to placeholders */
1576 for (i = 0; i <= xhv->xhv_max; i++) {
1577 HE *entry = (HvARRAY(hv))[i];
1578 for (; entry; entry = HeNEXT(entry)) {
1579 /* not already placeholder */
1580 if (HeVAL(entry) != &PL_sv_placeholder) {
1581 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1582 SV* const keysv = hv_iterkeysv(entry);
1584 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1587 SvREFCNT_dec(HeVAL(entry));
1588 HeVAL(entry) = &PL_sv_placeholder;
1589 HvPLACEHOLDERS(hv)++;
1597 HvPLACEHOLDERS_set(hv, 0);
1599 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1604 HvHASKFLAGS_off(hv);
1609 mro_isa_changed_in(hv);
1610 HvEITER_set(hv, NULL);
1615 =for apidoc hv_clear_placeholders
1617 Clears any placeholders from a hash. If a restricted hash has any of its keys
1618 marked as readonly and the key is subsequently deleted, the key is not actually
1619 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1620 it so it will be ignored by future operations such as iterating over the hash,
1621 but will still allow the hash to have a value reassigned to the key at some
1622 future point. This function clears any such placeholder keys from the hash.
1623 See Hash::Util::lock_keys() for an example of its use.
1629 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1632 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1635 clear_placeholders(hv, items);
1639 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1649 /* Loop down the linked list heads */
1651 HE **oentry = &(HvARRAY(hv))[i];
1654 while ((entry = *oentry)) {
1655 if (HeVAL(entry) == &PL_sv_placeholder) {
1656 *oentry = HeNEXT(entry);
1657 if (first && !*oentry)
1658 HvFILL(hv)--; /* This linked list is now empty. */
1659 if (entry == HvEITER_get(hv))
1662 hv_free_ent(hv, entry);
1666 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1667 if (HvKEYS(hv) == 0)
1668 HvHASKFLAGS_off(hv);
1669 HvPLACEHOLDERS_set(hv, 0);
1673 oentry = &HeNEXT(entry);
1678 /* You can't get here, hence assertion should always fail. */
1679 assert (items == 0);
1684 S_hfreeentries(pTHX_ HV *hv)
1686 /* This is the array that we're going to restore */
1687 HE **const orig_array = HvARRAY(hv);
1695 /* If the hash is actually a symbol table with a name, look after the
1697 struct xpvhv_aux *iter = HvAUX(hv);
1699 name = iter->xhv_name;
1700 iter->xhv_name = NULL;
1705 /* orig_array remains unchanged throughout the loop. If after freeing all
1706 the entries it turns out that one of the little blighters has triggered
1707 an action that has caused HvARRAY to be re-allocated, then we set
1708 array to the new HvARRAY, and try again. */
1711 /* This is the one we're going to try to empty. First time round
1712 it's the original array. (Hopefully there will only be 1 time
1714 HE ** const array = HvARRAY(hv);
1717 /* Because we have taken xhv_name out, the only allocated pointer
1718 in the aux structure that might exist is the backreference array.
1723 struct mro_meta *meta;
1724 struct xpvhv_aux *iter = HvAUX(hv);
1725 /* If there are weak references to this HV, we need to avoid
1726 freeing them up here. In particular we need to keep the AV
1727 visible as what we're deleting might well have weak references
1728 back to this HV, so the for loop below may well trigger
1729 the removal of backreferences from this array. */
1731 if (iter->xhv_backreferences) {
1732 /* So donate them to regular backref magic to keep them safe.
1733 The sv_magic will increase the reference count of the AV,
1734 so we need to drop it first. */
1735 SvREFCNT_dec(iter->xhv_backreferences);
1736 if (AvFILLp(iter->xhv_backreferences) == -1) {
1737 /* Turns out that the array is empty. Just free it. */
1738 SvREFCNT_dec(iter->xhv_backreferences);
1741 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1742 PERL_MAGIC_backref, NULL, 0);
1744 iter->xhv_backreferences = NULL;
1747 entry = iter->xhv_eiter; /* HvEITER(hv) */
1748 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1750 hv_free_ent(hv, entry);
1752 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1753 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1755 if((meta = iter->xhv_mro_meta)) {
1756 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1757 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1758 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1760 iter->xhv_mro_meta = NULL;
1763 /* There are now no allocated pointers in the aux structure. */
1765 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1766 /* What aux structure? */
1769 /* make everyone else think the array is empty, so that the destructors
1770 * called for freed entries can't recusively mess with us */
1773 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1777 /* Loop down the linked list heads */
1778 HE *entry = array[i];
1781 register HE * const oentry = entry;
1782 entry = HeNEXT(entry);
1783 hv_free_ent(hv, oentry);
1787 /* As there are no allocated pointers in the aux structure, it's now
1788 safe to free the array we just cleaned up, if it's not the one we're
1789 going to put back. */
1790 if (array != orig_array) {
1795 /* Good. No-one added anything this time round. */
1800 /* Someone attempted to iterate or set the hash name while we had
1801 the array set to 0. We'll catch backferences on the next time
1802 round the while loop. */
1803 assert(HvARRAY(hv));
1805 if (HvAUX(hv)->xhv_name) {
1806 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1810 if (--attempts == 0) {
1811 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1815 HvARRAY(hv) = orig_array;
1817 /* If the hash was actually a symbol table, put the name back. */
1819 /* We have restored the original array. If name is non-NULL, then
1820 the original array had an aux structure at the end. So this is
1822 SvFLAGS(hv) |= SVf_OOK;
1823 HvAUX(hv)->xhv_name = name;
1828 =for apidoc hv_undef
1836 Perl_hv_undef(pTHX_ HV *hv)
1839 register XPVHV* xhv;
1844 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1845 xhv = (XPVHV*)SvANY(hv);
1847 if ((name = HvNAME_get(hv)) && !PL_dirty)
1848 mro_isa_changed_in(hv);
1853 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1854 hv_name_set(hv, NULL, 0, 0);
1856 SvFLAGS(hv) &= ~SVf_OOK;
1857 Safefree(HvARRAY(hv));
1858 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1860 HvPLACEHOLDERS_set(hv, 0);
1866 static struct xpvhv_aux*
1867 S_hv_auxinit(HV *hv) {
1868 struct xpvhv_aux *iter;
1872 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1873 + sizeof(struct xpvhv_aux), char);
1875 array = (char *) HvARRAY(hv);
1876 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1877 + sizeof(struct xpvhv_aux), char);
1879 HvARRAY(hv) = (HE**) array;
1880 /* SvOOK_on(hv) attacks the IV flags. */
1881 SvFLAGS(hv) |= SVf_OOK;
1884 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1885 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1887 iter->xhv_backreferences = 0;
1888 iter->xhv_mro_meta = NULL;
1893 =for apidoc hv_iterinit
1895 Prepares a starting point to traverse a hash table. Returns the number of
1896 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1897 currently only meaningful for hashes without tie magic.
1899 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1900 hash buckets that happen to be in use. If you still need that esoteric
1901 value, you can get it through the macro C<HvFILL(tb)>.
1908 Perl_hv_iterinit(pTHX_ HV *hv)
1911 Perl_croak(aTHX_ "Bad hash");
1914 struct xpvhv_aux * const iter = HvAUX(hv);
1915 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1916 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1918 hv_free_ent(hv, entry);
1920 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1921 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1926 /* used to be xhv->xhv_fill before 5.004_65 */
1927 return HvTOTALKEYS(hv);
1931 Perl_hv_riter_p(pTHX_ HV *hv) {
1932 struct xpvhv_aux *iter;
1935 Perl_croak(aTHX_ "Bad hash");
1937 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1938 return &(iter->xhv_riter);
1942 Perl_hv_eiter_p(pTHX_ HV *hv) {
1943 struct xpvhv_aux *iter;
1946 Perl_croak(aTHX_ "Bad hash");
1948 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1949 return &(iter->xhv_eiter);
1953 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1954 struct xpvhv_aux *iter;
1957 Perl_croak(aTHX_ "Bad hash");
1965 iter = hv_auxinit(hv);
1967 iter->xhv_riter = riter;
1971 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1972 struct xpvhv_aux *iter;
1975 Perl_croak(aTHX_ "Bad hash");
1980 /* 0 is the default so don't go malloc()ing a new structure just to
1985 iter = hv_auxinit(hv);
1987 iter->xhv_eiter = eiter;
1991 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1994 struct xpvhv_aux *iter;
1997 PERL_UNUSED_ARG(flags);
2000 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2004 if (iter->xhv_name) {
2005 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2011 iter = hv_auxinit(hv);
2013 PERL_HASH(hash, name, len);
2014 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2018 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2019 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2020 PERL_UNUSED_CONTEXT;
2021 return &(iter->xhv_backreferences);
2025 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2031 av = HvAUX(hv)->xhv_backreferences;
2034 HvAUX(hv)->xhv_backreferences = 0;
2035 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2040 hv_iternext is implemented as a macro in hv.h
2042 =for apidoc hv_iternext
2044 Returns entries from a hash iterator. See C<hv_iterinit>.
2046 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2047 iterator currently points to, without losing your place or invalidating your
2048 iterator. Note that in this case the current entry is deleted from the hash
2049 with your iterator holding the last reference to it. Your iterator is flagged
2050 to free the entry on the next call to C<hv_iternext>, so you must not discard
2051 your iterator immediately else the entry will leak - call C<hv_iternext> to
2052 trigger the resource deallocation.
2054 =for apidoc hv_iternext_flags
2056 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2057 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2058 set the placeholders keys (for restricted hashes) will be returned in addition
2059 to normal keys. By default placeholders are automatically skipped over.
2060 Currently a placeholder is implemented with a value that is
2061 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2062 restricted hashes may change, and the implementation currently is
2063 insufficiently abstracted for any change to be tidy.
2069 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2072 register XPVHV* xhv;
2076 struct xpvhv_aux *iter;
2079 Perl_croak(aTHX_ "Bad hash");
2081 xhv = (XPVHV*)SvANY(hv);
2084 /* Too many things (well, pp_each at least) merrily assume that you can
2085 call iv_iternext without calling hv_iterinit, so we'll have to deal
2091 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2092 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2093 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2094 SV * const key = sv_newmortal();
2096 sv_setsv(key, HeSVKEY_force(entry));
2097 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2103 /* one HE per MAGICAL hash */
2104 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2106 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2108 HeKEY_hek(entry) = hek;
2109 HeKLEN(entry) = HEf_SVKEY;
2111 magic_nextpack((SV*) hv,mg,key);
2113 /* force key to stay around until next time */
2114 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2115 return entry; /* beware, hent_val is not set */
2118 SvREFCNT_dec(HeVAL(entry));
2119 Safefree(HeKEY_hek(entry));
2121 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2125 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2126 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2129 /* The prime_env_iter() on VMS just loaded up new hash values
2130 * so the iteration count needs to be reset back to the beginning
2134 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2139 /* hv_iterint now ensures this. */
2140 assert (HvARRAY(hv));
2142 /* At start of hash, entry is NULL. */
2145 entry = HeNEXT(entry);
2146 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2148 * Skip past any placeholders -- don't want to include them in
2151 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2152 entry = HeNEXT(entry);
2157 /* OK. Come to the end of the current list. Grab the next one. */
2159 iter->xhv_riter++; /* HvRITER(hv)++ */
2160 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2161 /* There is no next one. End of the hash. */
2162 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2165 entry = (HvARRAY(hv))[iter->xhv_riter];
2167 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2168 /* If we have an entry, but it's a placeholder, don't count it.
2170 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2171 entry = HeNEXT(entry);
2173 /* Will loop again if this linked list starts NULL
2174 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2175 or if we run through it and find only placeholders. */
2178 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2180 hv_free_ent(hv, oldentry);
2183 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2184 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2186 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2191 =for apidoc hv_iterkey
2193 Returns the key from the current position of the hash iterator. See
2200 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2202 if (HeKLEN(entry) == HEf_SVKEY) {
2204 char * const p = SvPV(HeKEY_sv(entry), len);
2209 *retlen = HeKLEN(entry);
2210 return HeKEY(entry);
2214 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2216 =for apidoc hv_iterkeysv
2218 Returns the key as an C<SV*> from the current position of the hash
2219 iterator. The return value will always be a mortal copy of the key. Also
2226 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2228 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2232 =for apidoc hv_iterval
2234 Returns the value from the current position of the hash iterator. See
2241 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2243 if (SvRMAGICAL(hv)) {
2244 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2245 SV* const sv = sv_newmortal();
2246 if (HeKLEN(entry) == HEf_SVKEY)
2247 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2249 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2253 return HeVAL(entry);
2257 =for apidoc hv_iternextsv
2259 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2266 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2268 HE * const he = hv_iternext_flags(hv, 0);
2272 *key = hv_iterkey(he, retlen);
2273 return hv_iterval(hv, he);
2280 =for apidoc hv_magic
2282 Adds magic to a hash. See C<sv_magic>.
2287 /* possibly free a shared string if no one has access to it
2288 * len and hash must both be valid for str.
2291 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2293 unshare_hek_or_pvn (NULL, str, len, hash);
2298 Perl_unshare_hek(pTHX_ HEK *hek)
2301 unshare_hek_or_pvn(hek, NULL, 0, 0);
2304 /* possibly free a shared string if no one has access to it
2305 hek if non-NULL takes priority over the other 3, else str, len and hash
2306 are used. If so, len and hash must both be valid for str.
2309 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2312 register XPVHV* xhv;
2314 register HE **oentry;
2316 bool is_utf8 = FALSE;
2318 const char * const save = str;
2319 struct shared_he *he = NULL;
2322 /* Find the shared he which is just before us in memory. */
2323 he = (struct shared_he *)(((char *)hek)
2324 - STRUCT_OFFSET(struct shared_he,
2327 /* Assert that the caller passed us a genuine (or at least consistent)
2329 assert (he->shared_he_he.hent_hek == hek);
2332 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2333 --he->shared_he_he.he_valu.hent_refcount;
2334 UNLOCK_STRTAB_MUTEX;
2337 UNLOCK_STRTAB_MUTEX;
2339 hash = HEK_HASH(hek);
2340 } else if (len < 0) {
2341 STRLEN tmplen = -len;
2343 /* See the note in hv_fetch(). --jhi */
2344 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2347 k_flags = HVhek_UTF8;
2349 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2352 /* what follows was the moral equivalent of:
2353 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2355 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2357 xhv = (XPVHV*)SvANY(PL_strtab);
2358 /* assert(xhv_array != 0) */
2360 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2362 const HE *const he_he = &(he->shared_he_he);
2363 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2368 const int flags_masked = k_flags & HVhek_MASK;
2369 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2370 if (HeHASH(entry) != hash) /* strings can't be equal */
2372 if (HeKLEN(entry) != len)
2374 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2376 if (HeKFLAGS(entry) != flags_masked)
2383 if (--entry->he_valu.hent_refcount == 0) {
2384 *oentry = HeNEXT(entry);
2386 /* There are now no entries in our slot. */
2387 xhv->xhv_fill--; /* HvFILL(hv)-- */
2390 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2394 UNLOCK_STRTAB_MUTEX;
2395 if (!entry && ckWARN_d(WARN_INTERNAL))
2396 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2397 "Attempt to free non-existent shared string '%s'%s"
2399 hek ? HEK_KEY(hek) : str,
2400 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2401 if (k_flags & HVhek_FREEKEY)
2405 /* get a (constant) string ptr from the global string table
2406 * string will get added if it is not already there.
2407 * len and hash must both be valid for str.
2410 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2412 bool is_utf8 = FALSE;
2414 const char * const save = str;
2417 STRLEN tmplen = -len;
2419 /* See the note in hv_fetch(). --jhi */
2420 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2422 /* If we were able to downgrade here, then than means that we were passed
2423 in a key which only had chars 0-255, but was utf8 encoded. */
2426 /* If we found we were able to downgrade the string to bytes, then
2427 we should flag that it needs upgrading on keys or each. Also flag
2428 that we need share_hek_flags to free the string. */
2430 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2433 return share_hek_flags (str, len, hash, flags);
2437 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2441 const int flags_masked = flags & HVhek_MASK;
2442 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2444 /* what follows is the moral equivalent of:
2446 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2447 hv_store(PL_strtab, str, len, NULL, hash);
2449 Can't rehash the shared string table, so not sure if it's worth
2450 counting the number of entries in the linked list
2452 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2453 /* assert(xhv_array != 0) */
2455 entry = (HvARRAY(PL_strtab))[hindex];
2456 for (;entry; entry = HeNEXT(entry)) {
2457 if (HeHASH(entry) != hash) /* strings can't be equal */
2459 if (HeKLEN(entry) != len)
2461 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2463 if (HeKFLAGS(entry) != flags_masked)
2469 /* What used to be head of the list.
2470 If this is NULL, then we're the first entry for this slot, which
2471 means we need to increate fill. */
2472 struct shared_he *new_entry;
2475 HE **const head = &HvARRAY(PL_strtab)[hindex];
2476 HE *const next = *head;
2478 /* We don't actually store a HE from the arena and a regular HEK.
2479 Instead we allocate one chunk of memory big enough for both,
2480 and put the HEK straight after the HE. This way we can find the
2481 HEK directly from the HE.
2484 Newx(k, STRUCT_OFFSET(struct shared_he,
2485 shared_he_hek.hek_key[0]) + len + 2, char);
2486 new_entry = (struct shared_he *)k;
2487 entry = &(new_entry->shared_he_he);
2488 hek = &(new_entry->shared_he_hek);
2490 Copy(str, HEK_KEY(hek), len, char);
2491 HEK_KEY(hek)[len] = 0;
2493 HEK_HASH(hek) = hash;
2494 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2496 /* Still "point" to the HEK, so that other code need not know what
2498 HeKEY_hek(entry) = hek;
2499 entry->he_valu.hent_refcount = 0;
2500 HeNEXT(entry) = next;
2503 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2504 if (!next) { /* initial entry? */
2505 xhv->xhv_fill++; /* HvFILL(hv)++ */
2506 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2511 ++entry->he_valu.hent_refcount;
2512 UNLOCK_STRTAB_MUTEX;
2514 if (flags & HVhek_FREEKEY)
2517 return HeKEY_hek(entry);
2521 Perl_hv_placeholders_p(pTHX_ HV *hv)
2524 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2527 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2530 Perl_die(aTHX_ "panic: hv_placeholders_p");
2533 return &(mg->mg_len);
2538 Perl_hv_placeholders_get(pTHX_ HV *hv)
2541 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2543 return mg ? mg->mg_len : 0;
2547 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2550 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2555 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2556 Perl_die(aTHX_ "panic: hv_placeholders_set");
2558 /* else we don't need to add magic to record 0 placeholders. */
2562 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2566 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2571 value = &PL_sv_placeholder;
2574 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2577 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2580 case HVrhek_PV_UTF8:
2581 /* Create a string SV that directly points to the bytes in our
2583 value = newSV_type(SVt_PV);
2584 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2585 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2586 /* This stops anything trying to free it */
2587 SvLEN_set(value, 0);
2589 SvREADONLY_on(value);
2590 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2594 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2595 he->refcounted_he_data[0]);
2601 =for apidoc refcounted_he_chain_2hv
2603 Generates and returns a C<HV *> by walking up the tree starting at the passed
2604 in C<struct refcounted_he *>.
2609 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2613 U32 placeholders = 0;
2614 /* We could chase the chain once to get an idea of the number of keys,
2615 and call ksplit. But for now we'll make a potentially inefficient
2616 hash with only 8 entries in its array. */
2617 const U32 max = HvMAX(hv);
2621 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2622 HvARRAY(hv) = (HE**)array;
2627 U32 hash = chain->refcounted_he_hash;
2629 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2631 HE **oentry = &((HvARRAY(hv))[hash & max]);
2632 HE *entry = *oentry;
2635 for (; entry; entry = HeNEXT(entry)) {
2636 if (HeHASH(entry) == hash) {
2637 /* We might have a duplicate key here. If so, entry is older
2638 than the key we've already put in the hash, so if they are
2639 the same, skip adding entry. */
2641 const STRLEN klen = HeKLEN(entry);
2642 const char *const key = HeKEY(entry);
2643 if (klen == chain->refcounted_he_keylen
2644 && (!!HeKUTF8(entry)
2645 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2646 && memEQ(key, REF_HE_KEY(chain), klen))
2649 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2651 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2652 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2653 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2664 = share_hek_flags(REF_HE_KEY(chain),
2665 chain->refcounted_he_keylen,
2666 chain->refcounted_he_hash,
2667 (chain->refcounted_he_data[0]
2668 & (HVhek_UTF8|HVhek_WASUTF8)));
2670 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2672 value = refcounted_he_value(chain);
2673 if (value == &PL_sv_placeholder)
2675 HeVAL(entry) = value;
2677 /* Link it into the chain. */
2678 HeNEXT(entry) = *oentry;
2679 if (!HeNEXT(entry)) {
2680 /* initial entry. */
2688 chain = chain->refcounted_he_next;
2692 clear_placeholders(hv, placeholders);
2693 HvTOTALKEYS(hv) -= placeholders;
2696 /* We could check in the loop to see if we encounter any keys with key
2697 flags, but it's probably not worth it, as this per-hash flag is only
2698 really meant as an optimisation for things like Storable. */
2700 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2706 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2707 const char *key, STRLEN klen, int flags, U32 hash)
2710 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2711 of your key has to exactly match that which is stored. */
2712 SV *value = &PL_sv_placeholder;
2716 if (flags & HVhek_FREEKEY)
2718 key = SvPV_const(keysv, klen);
2720 is_utf8 = (SvUTF8(keysv) != 0);
2722 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2726 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2727 hash = SvSHARED_HASH(keysv);
2729 PERL_HASH(hash, key, klen);
2733 for (; chain; chain = chain->refcounted_he_next) {
2735 if (hash != chain->refcounted_he_hash)
2737 if (klen != chain->refcounted_he_keylen)
2739 if (memNE(REF_HE_KEY(chain),key,klen))
2741 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2744 if (hash != HEK_HASH(chain->refcounted_he_hek))
2746 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2748 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2750 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2754 value = sv_2mortal(refcounted_he_value(chain));
2758 if (flags & HVhek_FREEKEY)
2765 =for apidoc refcounted_he_new
2767 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2768 stored in a compact form, all references remain the property of the caller.
2769 The C<struct refcounted_he> is returned with a reference count of 1.
2774 struct refcounted_he *
2775 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2776 SV *const key, SV *const value) {
2778 struct refcounted_he *he;
2780 const char *key_p = SvPV_const(key, key_len);
2781 STRLEN value_len = 0;
2782 const char *value_p = NULL;
2787 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2790 value_type = HVrhek_PV;
2791 } else if (SvIOK(value)) {
2792 value_type = HVrhek_IV;
2793 } else if (value == &PL_sv_placeholder) {
2794 value_type = HVrhek_delete;
2795 } else if (!SvOK(value)) {
2796 value_type = HVrhek_undef;
2798 value_type = HVrhek_PV;
2801 if (value_type == HVrhek_PV) {
2802 value_p = SvPV_const(value, value_len);
2803 key_offset = value_len + 2;
2810 he = (struct refcounted_he*)
2811 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2815 he = (struct refcounted_he*)
2816 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2821 he->refcounted_he_next = parent;
2823 if (value_type == HVrhek_PV) {
2824 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2825 he->refcounted_he_val.refcounted_he_u_len = value_len;
2826 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2827 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2829 value_type = HVrhek_PV_UTF8;
2830 } else if (value_type == HVrhek_IV) {
2832 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2833 value_type = HVrhek_UV;
2835 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2841 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2842 As we're going to be building hash keys from this value in future,
2843 normalise it now. */
2844 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2845 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2847 PERL_HASH(hash, key_p, key_len);
2850 he->refcounted_he_hash = hash;
2851 he->refcounted_he_keylen = key_len;
2852 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2854 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2857 if (flags & HVhek_WASUTF8) {
2858 /* If it was downgraded from UTF-8, then the pointer returned from
2859 bytes_from_utf8 is an allocated pointer that we must free. */
2863 he->refcounted_he_data[0] = flags;
2864 he->refcounted_he_refcnt = 1;
2870 =for apidoc refcounted_he_free
2872 Decrements the reference count of the passed in C<struct refcounted_he *>
2873 by one. If the reference count reaches zero the structure's memory is freed,
2874 and C<refcounted_he_free> iterates onto the parent node.
2880 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2882 PERL_UNUSED_CONTEXT;
2885 struct refcounted_he *copy;
2889 new_count = --he->refcounted_he_refcnt;
2890 HINTS_REFCNT_UNLOCK;
2896 #ifndef USE_ITHREADS
2897 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2900 he = he->refcounted_he_next;
2901 PerlMemShared_free(copy);
2906 =for apidoc hv_assert
2908 Check that a hash is in an internally consistent state.
2916 Perl_hv_assert(pTHX_ HV *hv)
2921 int placeholders = 0;
2924 const I32 riter = HvRITER_get(hv);
2925 HE *eiter = HvEITER_get(hv);
2927 (void)hv_iterinit(hv);
2929 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2930 /* sanity check the values */
2931 if (HeVAL(entry) == &PL_sv_placeholder)
2935 /* sanity check the keys */
2936 if (HeSVKEY(entry)) {
2937 NOOP; /* Don't know what to check on SV keys. */
2938 } else if (HeKUTF8(entry)) {
2940 if (HeKWASUTF8(entry)) {
2941 PerlIO_printf(Perl_debug_log,
2942 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2943 (int) HeKLEN(entry), HeKEY(entry));
2946 } else if (HeKWASUTF8(entry))
2949 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2950 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2951 const int nhashkeys = HvUSEDKEYS(hv);
2952 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2954 if (nhashkeys != real) {
2955 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2958 if (nhashplaceholders != placeholders) {
2959 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2963 if (withflags && ! HvHASKFLAGS(hv)) {
2964 PerlIO_printf(Perl_debug_log,
2965 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2972 HvRITER_set(hv, riter); /* Restore hash iterator state */
2973 HvEITER_set(hv, eiter);
2980 * c-indentation-style: bsd
2982 * indent-tabs-mode: t
2985 * ex: set ts=8 sts=4 sw=4 noet: