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 /* XXX This looks like an ideal candidate to inline */
263 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
264 register U32 hash, int flags)
266 HE * const hek = hv_common(hv, NULL, key, klen, flags,
267 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
268 return hek ? &HeVAL(hek) : NULL;
272 =for apidoc hv_store_ent
274 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
275 parameter is the precomputed hash value; if it is zero then Perl will
276 compute it. The return value is the new hash entry so created. It will be
277 NULL if the operation failed or if the value did not need to be actually
278 stored within the hash (as in the case of tied hashes). Otherwise the
279 contents of the return value can be accessed using the C<He?> macros
280 described here. Note that the caller is responsible for suitably
281 incrementing the reference count of C<val> before the call, and
282 decrementing it if the function returned NULL. Effectively a successful
283 hv_store_ent takes ownership of one reference to C<val>. This is
284 usually what you want; a newly created SV has a reference count of one, so
285 if all your code does is create SVs then store them in a hash, hv_store
286 will own the only reference to the new SV, and your code doesn't need to do
287 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
288 unlike C<val> it does not take ownership of it, so maintaining the correct
289 reference count on C<key> is entirely the caller's responsibility. hv_store
290 is not implemented as a call to hv_store_ent, and does not create a temporary
291 SV for the key, so if your key data is not already in SV form then use
292 hv_store in preference to hv_store_ent.
294 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
295 information on how to use this function on tied hashes.
300 /* XXX This looks like an ideal candidate to inline */
302 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
304 return hv_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
308 =for apidoc hv_exists
310 Returns a boolean indicating whether the specified hash key exists. The
311 C<klen> is the length of the key.
317 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
329 return hv_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
336 Returns the SV which corresponds to the specified key in the hash. The
337 C<klen> is the length of the key. If C<lval> is set then the fetch will be
338 part of a store. Check that the return value is non-null before
339 dereferencing it to an C<SV*>.
341 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
342 information on how to use this function on tied hashes.
348 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
361 hek = hv_common(hv, NULL, key, klen, flags, lval
362 ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
364 return hek ? &HeVAL(hek) : NULL;
368 =for apidoc hv_exists_ent
370 Returns a boolean indicating whether the specified hash key exists. C<hash>
371 can be a valid precomputed hash value, or 0 to ask for it to be
377 /* XXX This looks like an ideal candidate to inline */
379 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
381 return hv_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
385 /* returns an HE * structure with the all fields set */
386 /* note that hent_val will be a mortal sv for MAGICAL hashes */
388 =for apidoc hv_fetch_ent
390 Returns the hash entry which corresponds to the specified key in the hash.
391 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
392 if you want the function to compute it. IF C<lval> is set then the fetch
393 will be part of a store. Make sure the return value is non-null before
394 accessing it. The return value when C<tb> is a tied hash is a pointer to a
395 static location, so be sure to make a copy of the structure if you need to
398 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
399 information on how to use this function on tied hashes.
405 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
407 return hv_common(hv, keysv, NULL, 0, 0,
408 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
412 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
413 int flags, int action, SV *val, register U32 hash)
426 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
428 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
429 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
430 if (uf->uf_set == NULL) {
431 SV* obj = mg->mg_obj;
434 keysv = sv_2mortal(newSVpvn(key, klen));
435 if (flags & HVhek_UTF8)
439 mg->mg_obj = keysv; /* pass key */
440 uf->uf_index = action; /* pass action */
441 magic_getuvar((SV*)hv, mg);
442 keysv = mg->mg_obj; /* may have changed */
445 /* If the key may have changed, then we need to invalidate
446 any passed-in computed hash value. */
452 if (flags & HVhek_FREEKEY)
454 key = SvPV_const(keysv, klen);
456 is_utf8 = (SvUTF8(keysv) != 0);
458 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
461 if (action & HV_DELETE) {
462 return (HE *) hv_delete_common(hv, keysv, key, klen,
463 flags | (is_utf8 ? HVhek_UTF8 : 0),
467 xhv = (XPVHV*)SvANY(hv);
469 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
470 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
472 /* XXX should be able to skimp on the HE/HEK here when
473 HV_FETCH_JUST_SV is true. */
475 keysv = newSVpvn(key, klen);
480 keysv = newSVsv(keysv);
483 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
485 /* grab a fake HE/HEK pair from the pool or make a new one */
486 entry = PL_hv_fetch_ent_mh;
488 PL_hv_fetch_ent_mh = HeNEXT(entry);
492 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
493 HeKEY_hek(entry) = (HEK*)k;
495 HeNEXT(entry) = NULL;
496 HeSVKEY_set(entry, keysv);
498 sv_upgrade(sv, SVt_PVLV);
500 /* so we can free entry when freeing sv */
501 LvTARG(sv) = (SV*)entry;
503 /* XXX remove at some point? */
504 if (flags & HVhek_FREEKEY)
509 #ifdef ENV_IS_CASELESS
510 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
512 for (i = 0; i < klen; ++i)
513 if (isLOWER(key[i])) {
514 /* Would be nice if we had a routine to do the
515 copy and upercase in a single pass through. */
516 const char * const nkey = strupr(savepvn(key,klen));
517 /* Note that this fetch is for nkey (the uppercased
518 key) whereas the store is for key (the original) */
519 entry = hv_common(hv, NULL, nkey, klen,
520 HVhek_FREEKEY, /* free nkey */
521 0 /* non-LVAL fetch */
522 | HV_DISABLE_UVAR_XKEY,
524 0 /* compute hash */);
525 if (!entry && (action & HV_FETCH_LVALUE)) {
526 /* This call will free key if necessary.
527 Do it this way to encourage compiler to tail
529 entry = hv_common(hv, keysv, key, klen,
532 | HV_DISABLE_UVAR_XKEY,
535 if (flags & HVhek_FREEKEY)
543 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
544 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
545 /* I don't understand why hv_exists_ent has svret and sv,
546 whereas hv_exists only had one. */
547 SV * const svret = sv_newmortal();
550 if (keysv || is_utf8) {
552 keysv = newSVpvn(key, klen);
555 keysv = newSVsv(keysv);
557 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
559 mg_copy((SV*)hv, sv, key, klen);
561 if (flags & HVhek_FREEKEY)
563 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
564 /* This cast somewhat evil, but I'm merely using NULL/
565 not NULL to return the boolean exists.
566 And I know hv is not NULL. */
567 return SvTRUE(svret) ? (HE *)hv : NULL;
569 #ifdef ENV_IS_CASELESS
570 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
571 /* XXX This code isn't UTF8 clean. */
572 char * const keysave = (char * const)key;
573 /* Will need to free this, so set FREEKEY flag. */
574 key = savepvn(key,klen);
575 key = (const char*)strupr((char*)key);
580 if (flags & HVhek_FREEKEY) {
583 flags |= HVhek_FREEKEY;
587 else if (action & HV_FETCH_ISSTORE) {
590 hv_magic_check (hv, &needs_copy, &needs_store);
592 const bool save_taint = PL_tainted;
593 if (keysv || is_utf8) {
595 keysv = newSVpvn(key, klen);
599 PL_tainted = SvTAINTED(keysv);
600 keysv = sv_2mortal(newSVsv(keysv));
601 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
603 mg_copy((SV*)hv, val, key, klen);
606 TAINT_IF(save_taint);
608 if (flags & HVhek_FREEKEY)
612 #ifdef ENV_IS_CASELESS
613 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
614 /* XXX This code isn't UTF8 clean. */
615 const char *keysave = key;
616 /* Will need to free this, so set FREEKEY flag. */
617 key = savepvn(key,klen);
618 key = (const char*)strupr((char*)key);
623 if (flags & HVhek_FREEKEY) {
626 flags |= HVhek_FREEKEY;
634 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
635 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
636 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
641 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
643 HvARRAY(hv) = (HE**)array;
645 #ifdef DYNAMIC_ENV_FETCH
646 else if (action & HV_FETCH_ISEXISTS) {
647 /* for an %ENV exists, if we do an insert it's by a recursive
648 store call, so avoid creating HvARRAY(hv) right now. */
652 /* XXX remove at some point? */
653 if (flags & HVhek_FREEKEY)
661 char * const keysave = (char *)key;
662 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
666 flags &= ~HVhek_UTF8;
667 if (key != keysave) {
668 if (flags & HVhek_FREEKEY)
670 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
675 PERL_HASH_INTERNAL(hash, key, klen);
676 /* We don't have a pointer to the hv, so we have to replicate the
677 flag into every HEK, so that hv_iterkeysv can see it. */
678 /* And yes, you do need this even though you are not "storing" because
679 you can flip the flags below if doing an lval lookup. (And that
680 was put in to give the semantics Andreas was expecting.) */
681 flags |= HVhek_REHASH;
683 if (keysv && (SvIsCOW_shared_hash(keysv))) {
684 hash = SvSHARED_HASH(keysv);
686 PERL_HASH(hash, key, klen);
690 masked_flags = (flags & HVhek_MASK);
692 #ifdef DYNAMIC_ENV_FETCH
693 if (!HvARRAY(hv)) entry = NULL;
697 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
699 for (; entry; entry = HeNEXT(entry)) {
700 if (HeHASH(entry) != hash) /* strings can't be equal */
702 if (HeKLEN(entry) != (I32)klen)
704 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
706 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
709 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
710 if (HeKFLAGS(entry) != masked_flags) {
711 /* We match if HVhek_UTF8 bit in our flags and hash key's
712 match. But if entry was set previously with HVhek_WASUTF8
713 and key now doesn't (or vice versa) then we should change
714 the key's flag, as this is assignment. */
715 if (HvSHAREKEYS(hv)) {
716 /* Need to swap the key we have for a key with the flags we
717 need. As keys are shared we can't just write to the
718 flag, so we share the new one, unshare the old one. */
719 HEK * const new_hek = share_hek_flags(key, klen, hash,
721 unshare_hek (HeKEY_hek(entry));
722 HeKEY_hek(entry) = new_hek;
724 else if (hv == PL_strtab) {
725 /* PL_strtab is usually the only hash without HvSHAREKEYS,
726 so putting this test here is cheap */
727 if (flags & HVhek_FREEKEY)
729 Perl_croak(aTHX_ S_strtab_error,
730 action & HV_FETCH_LVALUE ? "fetch" : "store");
733 HeKFLAGS(entry) = masked_flags;
734 if (masked_flags & HVhek_ENABLEHVKFLAGS)
737 if (HeVAL(entry) == &PL_sv_placeholder) {
738 /* yes, can store into placeholder slot */
739 if (action & HV_FETCH_LVALUE) {
741 /* This preserves behaviour with the old hv_fetch
742 implementation which at this point would bail out
743 with a break; (at "if we find a placeholder, we
744 pretend we haven't found anything")
746 That break mean that if a placeholder were found, it
747 caused a call into hv_store, which in turn would
748 check magic, and if there is no magic end up pretty
749 much back at this point (in hv_store's code). */
752 /* LVAL fetch which actaully needs a store. */
754 HvPLACEHOLDERS(hv)--;
757 if (val != &PL_sv_placeholder)
758 HvPLACEHOLDERS(hv)--;
761 } else if (action & HV_FETCH_ISSTORE) {
762 SvREFCNT_dec(HeVAL(entry));
765 } else if (HeVAL(entry) == &PL_sv_placeholder) {
766 /* if we find a placeholder, we pretend we haven't found
770 if (flags & HVhek_FREEKEY)
774 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
775 if (!(action & HV_FETCH_ISSTORE)
776 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
778 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
780 sv = newSVpvn(env,len);
782 return hv_common(hv, keysv, key, klen, flags,
783 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, sv, hash);
788 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
789 hv_notallowed(flags, key, klen,
790 "Attempt to access disallowed key '%"SVf"' in"
791 " a restricted hash");
793 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
794 /* Not doing some form of store, so return failure. */
795 if (flags & HVhek_FREEKEY)
799 if (action & HV_FETCH_LVALUE) {
802 /* At this point the old hv_fetch code would call to hv_store,
803 which in turn might do some tied magic. So we need to make that
804 magic check happen. */
805 /* gonna assign to this, so it better be there */
806 /* If a fetch-as-store fails on the fetch, then the action is to
807 recurse once into "hv_store". If we didn't do this, then that
808 recursive call would call the key conversion routine again.
809 However, as we replace the original key with the converted
810 key, this would result in a double conversion, which would show
811 up as a bug if the conversion routine is not idempotent. */
812 return hv_common(hv, keysv, key, klen, flags,
813 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, val, hash);
814 /* XXX Surely that could leak if the fetch-was-store fails?
815 Just like the hv_fetch. */
819 /* Welcome to hv_store... */
822 /* Not sure if we can get here. I think the only case of oentry being
823 NULL is for %ENV with dynamic env fetch. But that should disappear
824 with magic in the previous code. */
827 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
829 HvARRAY(hv) = (HE**)array;
832 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
835 /* share_hek_flags will do the free for us. This might be considered
838 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
839 else if (hv == PL_strtab) {
840 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
841 this test here is cheap */
842 if (flags & HVhek_FREEKEY)
844 Perl_croak(aTHX_ S_strtab_error,
845 action & HV_FETCH_LVALUE ? "fetch" : "store");
847 else /* gotta do the real thing */
848 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
850 HeNEXT(entry) = *oentry;
853 if (val == &PL_sv_placeholder)
854 HvPLACEHOLDERS(hv)++;
855 if (masked_flags & HVhek_ENABLEHVKFLAGS)
859 const HE *counter = HeNEXT(entry);
861 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
862 if (!counter) { /* initial entry? */
863 xhv->xhv_fill++; /* HvFILL(hv)++ */
864 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
866 } else if(!HvREHASH(hv)) {
869 while ((counter = HeNEXT(counter)))
872 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
873 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
874 bucket splits on a rehashed hash, as we're not going to
875 split it again, and if someone is lucky (evil) enough to
876 get all the keys in one list they could exhaust our memory
877 as we repeatedly double the number of buckets on every
878 entry. Linear search feels a less worse thing to do. */
888 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
890 const MAGIC *mg = SvMAGIC(hv);
894 if (isUPPER(mg->mg_type)) {
896 if (mg->mg_type == PERL_MAGIC_tied) {
897 *needs_store = FALSE;
898 return; /* We've set all there is to set. */
901 mg = mg->mg_moremagic;
906 =for apidoc hv_scalar
908 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
914 Perl_hv_scalar(pTHX_ HV *hv)
918 if (SvRMAGICAL(hv)) {
919 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
921 return magic_scalarpack(hv, mg);
926 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
927 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
935 =for apidoc hv_delete
937 Deletes a key/value pair in the hash. The value SV is removed from the
938 hash and returned to the caller. The C<klen> is the length of the key.
939 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
946 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
953 k_flags = HVhek_UTF8;
958 return (SV *) hv_common(hv, NULL, key, klen, k_flags, flags | HV_DELETE,
963 =for apidoc hv_delete_ent
965 Deletes a key/value pair in the hash. The value SV is removed from the
966 hash and returned to the caller. The C<flags> value will normally be zero;
967 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
968 precomputed hash value, or 0 to ask for it to be computed.
973 /* XXX This looks like an ideal candidate to inline */
975 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
977 return (SV *) hv_common(hv, keysv, NULL, 0, 0, flags | HV_DELETE, NULL,
982 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
983 int k_flags, I32 d_flags, U32 hash)
988 register HE **oentry;
989 HE *const *first_entry;
990 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
993 if (SvRMAGICAL(hv)) {
996 hv_magic_check (hv, &needs_copy, &needs_store);
1000 entry = hv_common(hv, keysv, key, klen, k_flags & ~HVhek_FREEKEY,
1001 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY, NULL,
1003 sv = entry ? HeVAL(entry) : NULL;
1005 if (SvMAGICAL(sv)) {
1009 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1010 /* No longer an element */
1011 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1014 return NULL; /* element cannot be deleted */
1016 #ifdef ENV_IS_CASELESS
1017 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1018 /* XXX This code isn't UTF8 clean. */
1019 keysv = sv_2mortal(newSVpvn(key,klen));
1020 if (k_flags & HVhek_FREEKEY) {
1023 key = strupr(SvPVX(keysv));
1032 xhv = (XPVHV*)SvANY(hv);
1037 const char * const keysave = key;
1038 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1041 k_flags |= HVhek_UTF8;
1043 k_flags &= ~HVhek_UTF8;
1044 if (key != keysave) {
1045 if (k_flags & HVhek_FREEKEY) {
1046 /* This shouldn't happen if our caller does what we expect,
1047 but strictly the API allows it. */
1050 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1052 HvHASKFLAGS_on((SV*)hv);
1056 PERL_HASH_INTERNAL(hash, key, klen);
1058 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1059 hash = SvSHARED_HASH(keysv);
1061 PERL_HASH(hash, key, klen);
1065 masked_flags = (k_flags & HVhek_MASK);
1067 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1069 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1071 if (HeHASH(entry) != hash) /* strings can't be equal */
1073 if (HeKLEN(entry) != (I32)klen)
1075 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1077 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1080 if (hv == PL_strtab) {
1081 if (k_flags & HVhek_FREEKEY)
1083 Perl_croak(aTHX_ S_strtab_error, "delete");
1086 /* if placeholder is here, it's already been deleted.... */
1087 if (HeVAL(entry) == &PL_sv_placeholder) {
1088 if (k_flags & HVhek_FREEKEY)
1092 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1093 hv_notallowed(k_flags, key, klen,
1094 "Attempt to delete readonly key '%"SVf"' from"
1095 " a restricted hash");
1097 if (k_flags & HVhek_FREEKEY)
1100 if (d_flags & G_DISCARD)
1103 sv = sv_2mortal(HeVAL(entry));
1104 HeVAL(entry) = &PL_sv_placeholder;
1108 * If a restricted hash, rather than really deleting the entry, put
1109 * a placeholder there. This marks the key as being "approved", so
1110 * we can still access via not-really-existing key without raising
1113 if (SvREADONLY(hv)) {
1114 SvREFCNT_dec(HeVAL(entry));
1115 HeVAL(entry) = &PL_sv_placeholder;
1116 /* We'll be saving this slot, so the number of allocated keys
1117 * doesn't go down, but the number placeholders goes up */
1118 HvPLACEHOLDERS(hv)++;
1120 *oentry = HeNEXT(entry);
1122 xhv->xhv_fill--; /* HvFILL(hv)-- */
1124 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1127 hv_free_ent(hv, entry);
1128 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1129 if (xhv->xhv_keys == 0)
1130 HvHASKFLAGS_off(hv);
1134 if (SvREADONLY(hv)) {
1135 hv_notallowed(k_flags, key, klen,
1136 "Attempt to delete disallowed key '%"SVf"' from"
1137 " a restricted hash");
1140 if (k_flags & HVhek_FREEKEY)
1146 S_hsplit(pTHX_ HV *hv)
1149 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1150 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1151 register I32 newsize = oldsize * 2;
1153 char *a = (char*) HvARRAY(hv);
1155 register HE **oentry;
1156 int longest_chain = 0;
1159 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1160 (void*)hv, (int) oldsize);*/
1162 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1163 /* Can make this clear any placeholders first for non-restricted hashes,
1164 even though Storable rebuilds restricted hashes by putting in all the
1165 placeholders (first) before turning on the readonly flag, because
1166 Storable always pre-splits the hash. */
1167 hv_clear_placeholders(hv);
1171 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1172 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1173 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1179 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1182 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1183 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1188 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1190 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1192 if (oldsize >= 64) {
1193 offer_nice_chunk(HvARRAY(hv),
1194 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1195 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1198 Safefree(HvARRAY(hv));
1202 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1203 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1204 HvARRAY(hv) = (HE**) a;
1207 for (i=0; i<oldsize; i++,aep++) {
1208 int left_length = 0;
1209 int right_length = 0;
1213 if (!*aep) /* non-existent */
1216 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1217 if ((HeHASH(entry) & newsize) != (U32)i) {
1218 *oentry = HeNEXT(entry);
1219 HeNEXT(entry) = *bep;
1221 xhv->xhv_fill++; /* HvFILL(hv)++ */
1227 oentry = &HeNEXT(entry);
1231 if (!*aep) /* everything moved */
1232 xhv->xhv_fill--; /* HvFILL(hv)-- */
1233 /* I think we don't actually need to keep track of the longest length,
1234 merely flag if anything is too long. But for the moment while
1235 developing this code I'll track it. */
1236 if (left_length > longest_chain)
1237 longest_chain = left_length;
1238 if (right_length > longest_chain)
1239 longest_chain = right_length;
1243 /* Pick your policy for "hashing isn't working" here: */
1244 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1249 if (hv == PL_strtab) {
1250 /* Urg. Someone is doing something nasty to the string table.
1255 /* Awooga. Awooga. Pathological data. */
1256 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1257 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1260 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1261 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1263 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1266 was_shared = HvSHAREKEYS(hv);
1269 HvSHAREKEYS_off(hv);
1274 for (i=0; i<newsize; i++,aep++) {
1275 register HE *entry = *aep;
1277 /* We're going to trash this HE's next pointer when we chain it
1278 into the new hash below, so store where we go next. */
1279 HE * const next = HeNEXT(entry);
1284 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1289 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1290 hash, HeKFLAGS(entry));
1291 unshare_hek (HeKEY_hek(entry));
1292 HeKEY_hek(entry) = new_hek;
1294 /* Not shared, so simply write the new hash in. */
1295 HeHASH(entry) = hash;
1297 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1298 HEK_REHASH_on(HeKEY_hek(entry));
1299 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1301 /* Copy oentry to the correct new chain. */
1302 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1304 xhv->xhv_fill++; /* HvFILL(hv)++ */
1305 HeNEXT(entry) = *bep;
1311 Safefree (HvARRAY(hv));
1312 HvARRAY(hv) = (HE **)a;
1316 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1319 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1320 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1321 register I32 newsize;
1326 register HE **oentry;
1328 newsize = (I32) newmax; /* possible truncation here */
1329 if (newsize != newmax || newmax <= oldsize)
1331 while ((newsize & (1 + ~newsize)) != newsize) {
1332 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1334 if (newsize < newmax)
1336 if (newsize < newmax)
1337 return; /* overflow detection */
1339 a = (char *) HvARRAY(hv);
1342 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1343 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1344 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1350 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1353 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1354 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1359 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1361 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1363 if (oldsize >= 64) {
1364 offer_nice_chunk(HvARRAY(hv),
1365 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1366 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1369 Safefree(HvARRAY(hv));
1372 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1375 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1377 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1378 HvARRAY(hv) = (HE **) a;
1379 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1383 for (i=0; i<oldsize; i++,aep++) {
1384 if (!*aep) /* non-existent */
1386 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1387 register I32 j = (HeHASH(entry) & newsize);
1391 *oentry = HeNEXT(entry);
1392 if (!(HeNEXT(entry) = aep[j]))
1393 xhv->xhv_fill++; /* HvFILL(hv)++ */
1398 oentry = &HeNEXT(entry);
1400 if (!*aep) /* everything moved */
1401 xhv->xhv_fill--; /* HvFILL(hv)-- */
1408 Creates a new HV. The reference count is set to 1.
1416 register XPVHV* xhv;
1417 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1418 xhv = (XPVHV*)SvANY(hv);
1420 #ifndef NODEFAULT_SHAREKEYS
1421 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1424 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1425 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1430 Perl_newHVhv(pTHX_ HV *ohv)
1432 HV * const hv = newHV();
1433 STRLEN hv_max, hv_fill;
1435 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1437 hv_max = HvMAX(ohv);
1439 if (!SvMAGICAL((SV *)ohv)) {
1440 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1442 const bool shared = !!HvSHAREKEYS(ohv);
1443 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1445 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1448 /* In each bucket... */
1449 for (i = 0; i <= hv_max; i++) {
1451 HE *oent = oents[i];
1458 /* Copy the linked list of entries. */
1459 for (; oent; oent = HeNEXT(oent)) {
1460 const U32 hash = HeHASH(oent);
1461 const char * const key = HeKEY(oent);
1462 const STRLEN len = HeKLEN(oent);
1463 const int flags = HeKFLAGS(oent);
1464 HE * const ent = new_HE();
1466 HeVAL(ent) = newSVsv(HeVAL(oent));
1468 = shared ? share_hek_flags(key, len, hash, flags)
1469 : save_hek_flags(key, len, hash, flags);
1480 HvFILL(hv) = hv_fill;
1481 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1485 /* Iterate over ohv, copying keys and values one at a time. */
1487 const I32 riter = HvRITER_get(ohv);
1488 HE * const eiter = HvEITER_get(ohv);
1490 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1491 while (hv_max && hv_max + 1 >= hv_fill * 2)
1492 hv_max = hv_max / 2;
1496 while ((entry = hv_iternext_flags(ohv, 0))) {
1497 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1498 newSVsv(HeVAL(entry)), HeHASH(entry),
1501 HvRITER_set(ohv, riter);
1502 HvEITER_set(ohv, eiter);
1508 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1509 magic stays on it. */
1511 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1513 HV * const hv = newHV();
1516 if (ohv && (hv_fill = HvFILL(ohv))) {
1517 STRLEN hv_max = HvMAX(ohv);
1519 const I32 riter = HvRITER_get(ohv);
1520 HE * const eiter = HvEITER_get(ohv);
1522 while (hv_max && hv_max + 1 >= hv_fill * 2)
1523 hv_max = hv_max / 2;
1527 while ((entry = hv_iternext_flags(ohv, 0))) {
1528 SV *const sv = newSVsv(HeVAL(entry));
1529 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1530 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1531 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1532 sv, HeHASH(entry), HeKFLAGS(entry));
1534 HvRITER_set(ohv, riter);
1535 HvEITER_set(ohv, eiter);
1537 hv_magic(hv, NULL, PERL_MAGIC_hints);
1542 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1550 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1551 mro_method_changed_in(hv); /* deletion of method from stash */
1553 if (HeKLEN(entry) == HEf_SVKEY) {
1554 SvREFCNT_dec(HeKEY_sv(entry));
1555 Safefree(HeKEY_hek(entry));
1557 else if (HvSHAREKEYS(hv))
1558 unshare_hek(HeKEY_hek(entry));
1560 Safefree(HeKEY_hek(entry));
1565 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1570 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1571 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1572 if (HeKLEN(entry) == HEf_SVKEY) {
1573 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1575 hv_free_ent(hv, entry);
1579 =for apidoc hv_clear
1581 Clears a hash, making it empty.
1587 Perl_hv_clear(pTHX_ HV *hv)
1590 register XPVHV* xhv;
1594 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1596 xhv = (XPVHV*)SvANY(hv);
1598 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1599 /* restricted hash: convert all keys to placeholders */
1601 for (i = 0; i <= xhv->xhv_max; i++) {
1602 HE *entry = (HvARRAY(hv))[i];
1603 for (; entry; entry = HeNEXT(entry)) {
1604 /* not already placeholder */
1605 if (HeVAL(entry) != &PL_sv_placeholder) {
1606 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1607 SV* const keysv = hv_iterkeysv(entry);
1609 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1612 SvREFCNT_dec(HeVAL(entry));
1613 HeVAL(entry) = &PL_sv_placeholder;
1614 HvPLACEHOLDERS(hv)++;
1622 HvPLACEHOLDERS_set(hv, 0);
1624 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1629 HvHASKFLAGS_off(hv);
1634 mro_isa_changed_in(hv);
1635 HvEITER_set(hv, NULL);
1640 =for apidoc hv_clear_placeholders
1642 Clears any placeholders from a hash. If a restricted hash has any of its keys
1643 marked as readonly and the key is subsequently deleted, the key is not actually
1644 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1645 it so it will be ignored by future operations such as iterating over the hash,
1646 but will still allow the hash to have a value reassigned to the key at some
1647 future point. This function clears any such placeholder keys from the hash.
1648 See Hash::Util::lock_keys() for an example of its use.
1654 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1657 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1660 clear_placeholders(hv, items);
1664 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1674 /* Loop down the linked list heads */
1676 HE **oentry = &(HvARRAY(hv))[i];
1679 while ((entry = *oentry)) {
1680 if (HeVAL(entry) == &PL_sv_placeholder) {
1681 *oentry = HeNEXT(entry);
1682 if (first && !*oentry)
1683 HvFILL(hv)--; /* This linked list is now empty. */
1684 if (entry == HvEITER_get(hv))
1687 hv_free_ent(hv, entry);
1691 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1692 if (HvKEYS(hv) == 0)
1693 HvHASKFLAGS_off(hv);
1694 HvPLACEHOLDERS_set(hv, 0);
1698 oentry = &HeNEXT(entry);
1703 /* You can't get here, hence assertion should always fail. */
1704 assert (items == 0);
1709 S_hfreeentries(pTHX_ HV *hv)
1711 /* This is the array that we're going to restore */
1712 HE **const orig_array = HvARRAY(hv);
1720 /* If the hash is actually a symbol table with a name, look after the
1722 struct xpvhv_aux *iter = HvAUX(hv);
1724 name = iter->xhv_name;
1725 iter->xhv_name = NULL;
1730 /* orig_array remains unchanged throughout the loop. If after freeing all
1731 the entries it turns out that one of the little blighters has triggered
1732 an action that has caused HvARRAY to be re-allocated, then we set
1733 array to the new HvARRAY, and try again. */
1736 /* This is the one we're going to try to empty. First time round
1737 it's the original array. (Hopefully there will only be 1 time
1739 HE ** const array = HvARRAY(hv);
1742 /* Because we have taken xhv_name out, the only allocated pointer
1743 in the aux structure that might exist is the backreference array.
1748 struct mro_meta *meta;
1749 struct xpvhv_aux *iter = HvAUX(hv);
1750 /* If there are weak references to this HV, we need to avoid
1751 freeing them up here. In particular we need to keep the AV
1752 visible as what we're deleting might well have weak references
1753 back to this HV, so the for loop below may well trigger
1754 the removal of backreferences from this array. */
1756 if (iter->xhv_backreferences) {
1757 /* So donate them to regular backref magic to keep them safe.
1758 The sv_magic will increase the reference count of the AV,
1759 so we need to drop it first. */
1760 SvREFCNT_dec(iter->xhv_backreferences);
1761 if (AvFILLp(iter->xhv_backreferences) == -1) {
1762 /* Turns out that the array is empty. Just free it. */
1763 SvREFCNT_dec(iter->xhv_backreferences);
1766 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1767 PERL_MAGIC_backref, NULL, 0);
1769 iter->xhv_backreferences = NULL;
1772 entry = iter->xhv_eiter; /* HvEITER(hv) */
1773 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1775 hv_free_ent(hv, entry);
1777 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1778 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1780 if((meta = iter->xhv_mro_meta)) {
1781 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1782 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1783 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1785 iter->xhv_mro_meta = NULL;
1788 /* There are now no allocated pointers in the aux structure. */
1790 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1791 /* What aux structure? */
1794 /* make everyone else think the array is empty, so that the destructors
1795 * called for freed entries can't recusively mess with us */
1798 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1802 /* Loop down the linked list heads */
1803 HE *entry = array[i];
1806 register HE * const oentry = entry;
1807 entry = HeNEXT(entry);
1808 hv_free_ent(hv, oentry);
1812 /* As there are no allocated pointers in the aux structure, it's now
1813 safe to free the array we just cleaned up, if it's not the one we're
1814 going to put back. */
1815 if (array != orig_array) {
1820 /* Good. No-one added anything this time round. */
1825 /* Someone attempted to iterate or set the hash name while we had
1826 the array set to 0. We'll catch backferences on the next time
1827 round the while loop. */
1828 assert(HvARRAY(hv));
1830 if (HvAUX(hv)->xhv_name) {
1831 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1835 if (--attempts == 0) {
1836 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1840 HvARRAY(hv) = orig_array;
1842 /* If the hash was actually a symbol table, put the name back. */
1844 /* We have restored the original array. If name is non-NULL, then
1845 the original array had an aux structure at the end. So this is
1847 SvFLAGS(hv) |= SVf_OOK;
1848 HvAUX(hv)->xhv_name = name;
1853 =for apidoc hv_undef
1861 Perl_hv_undef(pTHX_ HV *hv)
1864 register XPVHV* xhv;
1869 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1870 xhv = (XPVHV*)SvANY(hv);
1872 if ((name = HvNAME_get(hv)) && !PL_dirty)
1873 mro_isa_changed_in(hv);
1878 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1879 hv_name_set(hv, NULL, 0, 0);
1881 SvFLAGS(hv) &= ~SVf_OOK;
1882 Safefree(HvARRAY(hv));
1883 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1885 HvPLACEHOLDERS_set(hv, 0);
1891 static struct xpvhv_aux*
1892 S_hv_auxinit(HV *hv) {
1893 struct xpvhv_aux *iter;
1897 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1898 + sizeof(struct xpvhv_aux), char);
1900 array = (char *) HvARRAY(hv);
1901 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1902 + sizeof(struct xpvhv_aux), char);
1904 HvARRAY(hv) = (HE**) array;
1905 /* SvOOK_on(hv) attacks the IV flags. */
1906 SvFLAGS(hv) |= SVf_OOK;
1909 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1910 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1912 iter->xhv_backreferences = 0;
1913 iter->xhv_mro_meta = NULL;
1918 =for apidoc hv_iterinit
1920 Prepares a starting point to traverse a hash table. Returns the number of
1921 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1922 currently only meaningful for hashes without tie magic.
1924 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1925 hash buckets that happen to be in use. If you still need that esoteric
1926 value, you can get it through the macro C<HvFILL(tb)>.
1933 Perl_hv_iterinit(pTHX_ HV *hv)
1936 Perl_croak(aTHX_ "Bad hash");
1939 struct xpvhv_aux * const iter = HvAUX(hv);
1940 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1941 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1943 hv_free_ent(hv, entry);
1945 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1946 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1951 /* used to be xhv->xhv_fill before 5.004_65 */
1952 return HvTOTALKEYS(hv);
1956 Perl_hv_riter_p(pTHX_ HV *hv) {
1957 struct xpvhv_aux *iter;
1960 Perl_croak(aTHX_ "Bad hash");
1962 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1963 return &(iter->xhv_riter);
1967 Perl_hv_eiter_p(pTHX_ HV *hv) {
1968 struct xpvhv_aux *iter;
1971 Perl_croak(aTHX_ "Bad hash");
1973 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1974 return &(iter->xhv_eiter);
1978 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1979 struct xpvhv_aux *iter;
1982 Perl_croak(aTHX_ "Bad hash");
1990 iter = hv_auxinit(hv);
1992 iter->xhv_riter = riter;
1996 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1997 struct xpvhv_aux *iter;
2000 Perl_croak(aTHX_ "Bad hash");
2005 /* 0 is the default so don't go malloc()ing a new structure just to
2010 iter = hv_auxinit(hv);
2012 iter->xhv_eiter = eiter;
2016 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2019 struct xpvhv_aux *iter;
2022 PERL_UNUSED_ARG(flags);
2025 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2029 if (iter->xhv_name) {
2030 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2036 iter = hv_auxinit(hv);
2038 PERL_HASH(hash, name, len);
2039 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2043 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2044 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2045 PERL_UNUSED_CONTEXT;
2046 return &(iter->xhv_backreferences);
2050 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2056 av = HvAUX(hv)->xhv_backreferences;
2059 HvAUX(hv)->xhv_backreferences = 0;
2060 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2065 hv_iternext is implemented as a macro in hv.h
2067 =for apidoc hv_iternext
2069 Returns entries from a hash iterator. See C<hv_iterinit>.
2071 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2072 iterator currently points to, without losing your place or invalidating your
2073 iterator. Note that in this case the current entry is deleted from the hash
2074 with your iterator holding the last reference to it. Your iterator is flagged
2075 to free the entry on the next call to C<hv_iternext>, so you must not discard
2076 your iterator immediately else the entry will leak - call C<hv_iternext> to
2077 trigger the resource deallocation.
2079 =for apidoc hv_iternext_flags
2081 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2082 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2083 set the placeholders keys (for restricted hashes) will be returned in addition
2084 to normal keys. By default placeholders are automatically skipped over.
2085 Currently a placeholder is implemented with a value that is
2086 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2087 restricted hashes may change, and the implementation currently is
2088 insufficiently abstracted for any change to be tidy.
2094 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2097 register XPVHV* xhv;
2101 struct xpvhv_aux *iter;
2104 Perl_croak(aTHX_ "Bad hash");
2106 xhv = (XPVHV*)SvANY(hv);
2109 /* Too many things (well, pp_each at least) merrily assume that you can
2110 call iv_iternext without calling hv_iterinit, so we'll have to deal
2116 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2117 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2118 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2119 SV * const key = sv_newmortal();
2121 sv_setsv(key, HeSVKEY_force(entry));
2122 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2128 /* one HE per MAGICAL hash */
2129 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2131 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2133 HeKEY_hek(entry) = hek;
2134 HeKLEN(entry) = HEf_SVKEY;
2136 magic_nextpack((SV*) hv,mg,key);
2138 /* force key to stay around until next time */
2139 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2140 return entry; /* beware, hent_val is not set */
2143 SvREFCNT_dec(HeVAL(entry));
2144 Safefree(HeKEY_hek(entry));
2146 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2150 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2151 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2154 /* The prime_env_iter() on VMS just loaded up new hash values
2155 * so the iteration count needs to be reset back to the beginning
2159 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2164 /* hv_iterint now ensures this. */
2165 assert (HvARRAY(hv));
2167 /* At start of hash, entry is NULL. */
2170 entry = HeNEXT(entry);
2171 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2173 * Skip past any placeholders -- don't want to include them in
2176 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2177 entry = HeNEXT(entry);
2182 /* OK. Come to the end of the current list. Grab the next one. */
2184 iter->xhv_riter++; /* HvRITER(hv)++ */
2185 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2186 /* There is no next one. End of the hash. */
2187 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2190 entry = (HvARRAY(hv))[iter->xhv_riter];
2192 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2193 /* If we have an entry, but it's a placeholder, don't count it.
2195 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2196 entry = HeNEXT(entry);
2198 /* Will loop again if this linked list starts NULL
2199 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2200 or if we run through it and find only placeholders. */
2203 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2205 hv_free_ent(hv, oldentry);
2208 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2209 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2211 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2216 =for apidoc hv_iterkey
2218 Returns the key from the current position of the hash iterator. See
2225 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2227 if (HeKLEN(entry) == HEf_SVKEY) {
2229 char * const p = SvPV(HeKEY_sv(entry), len);
2234 *retlen = HeKLEN(entry);
2235 return HeKEY(entry);
2239 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2241 =for apidoc hv_iterkeysv
2243 Returns the key as an C<SV*> from the current position of the hash
2244 iterator. The return value will always be a mortal copy of the key. Also
2251 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2253 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2257 =for apidoc hv_iterval
2259 Returns the value from the current position of the hash iterator. See
2266 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2268 if (SvRMAGICAL(hv)) {
2269 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2270 SV* const sv = sv_newmortal();
2271 if (HeKLEN(entry) == HEf_SVKEY)
2272 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2274 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2278 return HeVAL(entry);
2282 =for apidoc hv_iternextsv
2284 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2291 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2293 HE * const he = hv_iternext_flags(hv, 0);
2297 *key = hv_iterkey(he, retlen);
2298 return hv_iterval(hv, he);
2305 =for apidoc hv_magic
2307 Adds magic to a hash. See C<sv_magic>.
2312 /* possibly free a shared string if no one has access to it
2313 * len and hash must both be valid for str.
2316 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2318 unshare_hek_or_pvn (NULL, str, len, hash);
2323 Perl_unshare_hek(pTHX_ HEK *hek)
2326 unshare_hek_or_pvn(hek, NULL, 0, 0);
2329 /* possibly free a shared string if no one has access to it
2330 hek if non-NULL takes priority over the other 3, else str, len and hash
2331 are used. If so, len and hash must both be valid for str.
2334 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2337 register XPVHV* xhv;
2339 register HE **oentry;
2341 bool is_utf8 = FALSE;
2343 const char * const save = str;
2344 struct shared_he *he = NULL;
2347 /* Find the shared he which is just before us in memory. */
2348 he = (struct shared_he *)(((char *)hek)
2349 - STRUCT_OFFSET(struct shared_he,
2352 /* Assert that the caller passed us a genuine (or at least consistent)
2354 assert (he->shared_he_he.hent_hek == hek);
2357 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2358 --he->shared_he_he.he_valu.hent_refcount;
2359 UNLOCK_STRTAB_MUTEX;
2362 UNLOCK_STRTAB_MUTEX;
2364 hash = HEK_HASH(hek);
2365 } else if (len < 0) {
2366 STRLEN tmplen = -len;
2368 /* See the note in hv_fetch(). --jhi */
2369 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2372 k_flags = HVhek_UTF8;
2374 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2377 /* what follows was the moral equivalent of:
2378 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2380 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2382 xhv = (XPVHV*)SvANY(PL_strtab);
2383 /* assert(xhv_array != 0) */
2385 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2387 const HE *const he_he = &(he->shared_he_he);
2388 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2393 const int flags_masked = k_flags & HVhek_MASK;
2394 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2395 if (HeHASH(entry) != hash) /* strings can't be equal */
2397 if (HeKLEN(entry) != len)
2399 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2401 if (HeKFLAGS(entry) != flags_masked)
2408 if (--entry->he_valu.hent_refcount == 0) {
2409 *oentry = HeNEXT(entry);
2411 /* There are now no entries in our slot. */
2412 xhv->xhv_fill--; /* HvFILL(hv)-- */
2415 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2419 UNLOCK_STRTAB_MUTEX;
2420 if (!entry && ckWARN_d(WARN_INTERNAL))
2421 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2422 "Attempt to free non-existent shared string '%s'%s"
2424 hek ? HEK_KEY(hek) : str,
2425 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2426 if (k_flags & HVhek_FREEKEY)
2430 /* get a (constant) string ptr from the global string table
2431 * string will get added if it is not already there.
2432 * len and hash must both be valid for str.
2435 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2437 bool is_utf8 = FALSE;
2439 const char * const save = str;
2442 STRLEN tmplen = -len;
2444 /* See the note in hv_fetch(). --jhi */
2445 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2447 /* If we were able to downgrade here, then than means that we were passed
2448 in a key which only had chars 0-255, but was utf8 encoded. */
2451 /* If we found we were able to downgrade the string to bytes, then
2452 we should flag that it needs upgrading on keys or each. Also flag
2453 that we need share_hek_flags to free the string. */
2455 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2458 return share_hek_flags (str, len, hash, flags);
2462 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2466 const int flags_masked = flags & HVhek_MASK;
2467 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2469 /* what follows is the moral equivalent of:
2471 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2472 hv_store(PL_strtab, str, len, NULL, hash);
2474 Can't rehash the shared string table, so not sure if it's worth
2475 counting the number of entries in the linked list
2477 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2478 /* assert(xhv_array != 0) */
2480 entry = (HvARRAY(PL_strtab))[hindex];
2481 for (;entry; entry = HeNEXT(entry)) {
2482 if (HeHASH(entry) != hash) /* strings can't be equal */
2484 if (HeKLEN(entry) != len)
2486 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2488 if (HeKFLAGS(entry) != flags_masked)
2494 /* What used to be head of the list.
2495 If this is NULL, then we're the first entry for this slot, which
2496 means we need to increate fill. */
2497 struct shared_he *new_entry;
2500 HE **const head = &HvARRAY(PL_strtab)[hindex];
2501 HE *const next = *head;
2503 /* We don't actually store a HE from the arena and a regular HEK.
2504 Instead we allocate one chunk of memory big enough for both,
2505 and put the HEK straight after the HE. This way we can find the
2506 HEK directly from the HE.
2509 Newx(k, STRUCT_OFFSET(struct shared_he,
2510 shared_he_hek.hek_key[0]) + len + 2, char);
2511 new_entry = (struct shared_he *)k;
2512 entry = &(new_entry->shared_he_he);
2513 hek = &(new_entry->shared_he_hek);
2515 Copy(str, HEK_KEY(hek), len, char);
2516 HEK_KEY(hek)[len] = 0;
2518 HEK_HASH(hek) = hash;
2519 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2521 /* Still "point" to the HEK, so that other code need not know what
2523 HeKEY_hek(entry) = hek;
2524 entry->he_valu.hent_refcount = 0;
2525 HeNEXT(entry) = next;
2528 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2529 if (!next) { /* initial entry? */
2530 xhv->xhv_fill++; /* HvFILL(hv)++ */
2531 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2536 ++entry->he_valu.hent_refcount;
2537 UNLOCK_STRTAB_MUTEX;
2539 if (flags & HVhek_FREEKEY)
2542 return HeKEY_hek(entry);
2546 Perl_hv_placeholders_p(pTHX_ HV *hv)
2549 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2552 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2555 Perl_die(aTHX_ "panic: hv_placeholders_p");
2558 return &(mg->mg_len);
2563 Perl_hv_placeholders_get(pTHX_ HV *hv)
2566 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2568 return mg ? mg->mg_len : 0;
2572 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2575 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2580 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2581 Perl_die(aTHX_ "panic: hv_placeholders_set");
2583 /* else we don't need to add magic to record 0 placeholders. */
2587 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2591 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2596 value = &PL_sv_placeholder;
2599 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2602 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2605 case HVrhek_PV_UTF8:
2606 /* Create a string SV that directly points to the bytes in our
2608 value = newSV_type(SVt_PV);
2609 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2610 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2611 /* This stops anything trying to free it */
2612 SvLEN_set(value, 0);
2614 SvREADONLY_on(value);
2615 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2619 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2620 he->refcounted_he_data[0]);
2626 =for apidoc refcounted_he_chain_2hv
2628 Generates and returns a C<HV *> by walking up the tree starting at the passed
2629 in C<struct refcounted_he *>.
2634 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2638 U32 placeholders = 0;
2639 /* We could chase the chain once to get an idea of the number of keys,
2640 and call ksplit. But for now we'll make a potentially inefficient
2641 hash with only 8 entries in its array. */
2642 const U32 max = HvMAX(hv);
2646 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2647 HvARRAY(hv) = (HE**)array;
2652 U32 hash = chain->refcounted_he_hash;
2654 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2656 HE **oentry = &((HvARRAY(hv))[hash & max]);
2657 HE *entry = *oentry;
2660 for (; entry; entry = HeNEXT(entry)) {
2661 if (HeHASH(entry) == hash) {
2662 /* We might have a duplicate key here. If so, entry is older
2663 than the key we've already put in the hash, so if they are
2664 the same, skip adding entry. */
2666 const STRLEN klen = HeKLEN(entry);
2667 const char *const key = HeKEY(entry);
2668 if (klen == chain->refcounted_he_keylen
2669 && (!!HeKUTF8(entry)
2670 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2671 && memEQ(key, REF_HE_KEY(chain), klen))
2674 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2676 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2677 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2678 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2689 = share_hek_flags(REF_HE_KEY(chain),
2690 chain->refcounted_he_keylen,
2691 chain->refcounted_he_hash,
2692 (chain->refcounted_he_data[0]
2693 & (HVhek_UTF8|HVhek_WASUTF8)));
2695 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2697 value = refcounted_he_value(chain);
2698 if (value == &PL_sv_placeholder)
2700 HeVAL(entry) = value;
2702 /* Link it into the chain. */
2703 HeNEXT(entry) = *oentry;
2704 if (!HeNEXT(entry)) {
2705 /* initial entry. */
2713 chain = chain->refcounted_he_next;
2717 clear_placeholders(hv, placeholders);
2718 HvTOTALKEYS(hv) -= placeholders;
2721 /* We could check in the loop to see if we encounter any keys with key
2722 flags, but it's probably not worth it, as this per-hash flag is only
2723 really meant as an optimisation for things like Storable. */
2725 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2731 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2732 const char *key, STRLEN klen, int flags, U32 hash)
2735 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2736 of your key has to exactly match that which is stored. */
2737 SV *value = &PL_sv_placeholder;
2741 if (flags & HVhek_FREEKEY)
2743 key = SvPV_const(keysv, klen);
2745 is_utf8 = (SvUTF8(keysv) != 0);
2747 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2751 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2752 hash = SvSHARED_HASH(keysv);
2754 PERL_HASH(hash, key, klen);
2758 for (; chain; chain = chain->refcounted_he_next) {
2760 if (hash != chain->refcounted_he_hash)
2762 if (klen != chain->refcounted_he_keylen)
2764 if (memNE(REF_HE_KEY(chain),key,klen))
2766 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2769 if (hash != HEK_HASH(chain->refcounted_he_hek))
2771 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2773 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2775 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2779 value = sv_2mortal(refcounted_he_value(chain));
2783 if (flags & HVhek_FREEKEY)
2790 =for apidoc refcounted_he_new
2792 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2793 stored in a compact form, all references remain the property of the caller.
2794 The C<struct refcounted_he> is returned with a reference count of 1.
2799 struct refcounted_he *
2800 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2801 SV *const key, SV *const value) {
2803 struct refcounted_he *he;
2805 const char *key_p = SvPV_const(key, key_len);
2806 STRLEN value_len = 0;
2807 const char *value_p = NULL;
2812 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2815 value_type = HVrhek_PV;
2816 } else if (SvIOK(value)) {
2817 value_type = HVrhek_IV;
2818 } else if (value == &PL_sv_placeholder) {
2819 value_type = HVrhek_delete;
2820 } else if (!SvOK(value)) {
2821 value_type = HVrhek_undef;
2823 value_type = HVrhek_PV;
2826 if (value_type == HVrhek_PV) {
2827 value_p = SvPV_const(value, value_len);
2828 key_offset = value_len + 2;
2835 he = (struct refcounted_he*)
2836 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2840 he = (struct refcounted_he*)
2841 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2846 he->refcounted_he_next = parent;
2848 if (value_type == HVrhek_PV) {
2849 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2850 he->refcounted_he_val.refcounted_he_u_len = value_len;
2851 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2852 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2854 value_type = HVrhek_PV_UTF8;
2855 } else if (value_type == HVrhek_IV) {
2857 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2858 value_type = HVrhek_UV;
2860 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2866 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2867 As we're going to be building hash keys from this value in future,
2868 normalise it now. */
2869 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2870 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2872 PERL_HASH(hash, key_p, key_len);
2875 he->refcounted_he_hash = hash;
2876 he->refcounted_he_keylen = key_len;
2877 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2879 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2882 if (flags & HVhek_WASUTF8) {
2883 /* If it was downgraded from UTF-8, then the pointer returned from
2884 bytes_from_utf8 is an allocated pointer that we must free. */
2888 he->refcounted_he_data[0] = flags;
2889 he->refcounted_he_refcnt = 1;
2895 =for apidoc refcounted_he_free
2897 Decrements the reference count of the passed in C<struct refcounted_he *>
2898 by one. If the reference count reaches zero the structure's memory is freed,
2899 and C<refcounted_he_free> iterates onto the parent node.
2905 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2907 PERL_UNUSED_CONTEXT;
2910 struct refcounted_he *copy;
2914 new_count = --he->refcounted_he_refcnt;
2915 HINTS_REFCNT_UNLOCK;
2921 #ifndef USE_ITHREADS
2922 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2925 he = he->refcounted_he_next;
2926 PerlMemShared_free(copy);
2931 =for apidoc hv_assert
2933 Check that a hash is in an internally consistent state.
2941 Perl_hv_assert(pTHX_ HV *hv)
2946 int placeholders = 0;
2949 const I32 riter = HvRITER_get(hv);
2950 HE *eiter = HvEITER_get(hv);
2952 (void)hv_iterinit(hv);
2954 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2955 /* sanity check the values */
2956 if (HeVAL(entry) == &PL_sv_placeholder)
2960 /* sanity check the keys */
2961 if (HeSVKEY(entry)) {
2962 NOOP; /* Don't know what to check on SV keys. */
2963 } else if (HeKUTF8(entry)) {
2965 if (HeKWASUTF8(entry)) {
2966 PerlIO_printf(Perl_debug_log,
2967 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2968 (int) HeKLEN(entry), HeKEY(entry));
2971 } else if (HeKWASUTF8(entry))
2974 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2975 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2976 const int nhashkeys = HvUSEDKEYS(hv);
2977 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2979 if (nhashkeys != real) {
2980 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2983 if (nhashplaceholders != placeholders) {
2984 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2988 if (withflags && ! HvHASKFLAGS(hv)) {
2989 PerlIO_printf(Perl_debug_log,
2990 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2997 HvRITER_set(hv, riter); /* Restore hash iterator state */
2998 HvEITER_set(hv, eiter);
3005 * c-indentation-style: bsd
3007 * indent-tabs-mode: t
3010 * ex: set ts=8 sts=4 sw=4 noet: