3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
36 static const char S_strtab_error[]
37 = "Cannot modify shared string table in hv_%s";
43 HE* he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
44 HE * const heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
46 PL_body_roots[HE_SVSLOT] = he;
48 HeNEXT(he) = (HE*)(he + 1);
56 #define new_HE() (HE*)safemalloc(sizeof(HE))
57 #define del_HE(p) safefree((char*)p)
66 void ** const root = &PL_body_roots[HE_SVSLOT];
76 #define new_HE() new_he()
79 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
80 PL_body_roots[HE_SVSLOT] = p; \
88 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
90 const int flags_masked = flags & HVhek_MASK;
94 Newx(k, HEK_BASESIZE + len + 2, char);
96 Copy(str, HEK_KEY(hek), len, char);
97 HEK_KEY(hek)[len] = 0;
100 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
102 if (flags & HVhek_FREEKEY)
107 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
111 Perl_free_tied_hv_pool(pTHX)
114 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
121 PL_hv_fetch_ent_mh = NULL;
124 #if defined(USE_ITHREADS)
126 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
128 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 PERL_UNUSED_ARG(param);
133 /* We already shared this hash key. */
134 (void)share_hek_hek(shared);
138 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
139 HEK_HASH(source), HEK_FLAGS(source));
140 ptr_table_store(PL_ptr_table, source, shared);
146 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
152 /* look for it in the table first */
153 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
157 /* create anew and remember what it is */
159 ptr_table_store(PL_ptr_table, e, ret);
161 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
162 if (HeKLEN(e) == HEf_SVKEY) {
164 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
165 HeKEY_hek(ret) = (HEK*)k;
166 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
169 /* This is hek_dup inlined, which seems to be important for speed
171 HEK * const source = HeKEY_hek(e);
172 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
175 /* We already shared this hash key. */
176 (void)share_hek_hek(shared);
180 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
181 HEK_HASH(source), HEK_FLAGS(source));
182 ptr_table_store(PL_ptr_table, source, shared);
184 HeKEY_hek(ret) = shared;
187 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
189 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
192 #endif /* USE_ITHREADS */
195 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
198 SV * const sv = sv_newmortal();
199 if (!(flags & HVhek_FREEKEY)) {
200 sv_setpvn(sv, key, klen);
203 /* Need to free saved eventually assign to mortal SV */
204 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
205 sv_usepvn(sv, (char *) key, klen);
207 if (flags & HVhek_UTF8) {
210 Perl_croak(aTHX_ msg, SVfARG(sv));
213 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
219 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
220 the length of the key. The C<hash> parameter is the precomputed hash
221 value; if it is zero then Perl will compute it. The return value will be
222 NULL if the operation failed or if the value did not need to be actually
223 stored within the hash (as in the case of tied hashes). Otherwise it can
224 be dereferenced to get the original C<SV*>. Note that the caller is
225 responsible for suitably incrementing the reference count of C<val> before
226 the call, and decrementing it if the function returned NULL. Effectively
227 a successful hv_store takes ownership of one reference to C<val>. This is
228 usually what you want; a newly created SV has a reference count of one, so
229 if all your code does is create SVs then store them in a hash, hv_store
230 will own the only reference to the new SV, and your code doesn't need to do
231 anything further to tidy up. hv_store is not implemented as a call to
232 hv_store_ent, and does not create a temporary SV for the key, so if your
233 key data is not already in SV form then use hv_store in preference to
236 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
237 information on how to use this function on tied hashes.
243 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
256 hek = hv_fetch_common (hv, NULL, key, klen, flags,
257 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
258 return hek ? &HeVAL(hek) : NULL;
261 /* XXX This looks like an ideal candidate to inline */
263 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
264 register U32 hash, int flags)
266 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
267 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
268 return hek ? &HeVAL(hek) : NULL;
272 =for apidoc hv_store_ent
274 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
275 parameter is the precomputed hash value; if it is zero then Perl will
276 compute it. The return value is the new hash entry so created. It will be
277 NULL if the operation failed or if the value did not need to be actually
278 stored within the hash (as in the case of tied hashes). Otherwise the
279 contents of the return value can be accessed using the C<He?> macros
280 described here. Note that the caller is responsible for suitably
281 incrementing the reference count of C<val> before the call, and
282 decrementing it if the function returned NULL. Effectively a successful
283 hv_store_ent takes ownership of one reference to C<val>. This is
284 usually what you want; a newly created SV has a reference count of one, so
285 if all your code does is create SVs then store them in a hash, hv_store
286 will own the only reference to the new SV, and your code doesn't need to do
287 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
288 unlike C<val> it does not take ownership of it, so maintaining the correct
289 reference count on C<key> is entirely the caller's responsibility. hv_store
290 is not implemented as a call to hv_store_ent, and does not create a temporary
291 SV for the key, so if your key data is not already in SV form then use
292 hv_store in preference to hv_store_ent.
294 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
295 information on how to use this function on tied hashes.
300 /* XXX This looks like an ideal candidate to inline */
302 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
304 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
308 =for apidoc hv_exists
310 Returns a boolean indicating whether the specified hash key exists. The
311 C<klen> is the length of the key.
317 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
329 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
336 Returns the SV which corresponds to the specified key in the hash. The
337 C<klen> is the length of the key. If C<lval> is set then the fetch will be
338 part of a store. Check that the return value is non-null before
339 dereferencing it to an C<SV*>.
341 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
342 information on how to use this function on tied hashes.
348 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
361 hek = hv_fetch_common (hv, NULL, key, klen, flags,
362 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
364 return hek ? &HeVAL(hek) : NULL;
368 =for apidoc hv_exists_ent
370 Returns a boolean indicating whether the specified hash key exists. C<hash>
371 can be a valid precomputed hash value, or 0 to ask for it to be
377 /* XXX This looks like an ideal candidate to inline */
379 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
381 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
385 /* returns an HE * structure with the all fields set */
386 /* note that hent_val will be a mortal sv for MAGICAL hashes */
388 =for apidoc hv_fetch_ent
390 Returns the hash entry which corresponds to the specified key in the hash.
391 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
392 if you want the function to compute it. IF C<lval> is set then the fetch
393 will be part of a store. Make sure the return value is non-null before
394 accessing it. The return value when C<tb> is a tied hash is a pointer to a
395 static location, so be sure to make a copy of the structure if you need to
398 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
399 information on how to use this function on tied hashes.
405 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
407 return hv_fetch_common(hv, keysv, NULL, 0, 0,
408 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
412 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
413 int flags, int action, SV *val, register U32 hash)
427 if (SvSMAGICAL(hv) && SvGMAGICAL(hv)
428 && !(action & HV_DISABLE_UVAR_XKEY)) {
429 keysv = hv_magic_uvar_xkey(hv, keysv, action);
430 /* If a fetch-as-store fails on the fetch, then the action is to
431 recurse once into "hv_store". If we didn't do this, then that
432 recursive call would call the key conversion routine again.
433 However, as we replace the original key with the converted
434 key, this would result in a double conversion, which would show
435 up as a bug if the conversion routine is not idempotent. */
437 if (flags & HVhek_FREEKEY)
439 key = SvPV_const(keysv, klen);
441 is_utf8 = (SvUTF8(keysv) != 0);
443 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
446 xhv = (XPVHV*)SvANY(hv);
448 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
449 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
451 /* XXX should be able to skimp on the HE/HEK here when
452 HV_FETCH_JUST_SV is true. */
454 keysv = newSVpvn(key, klen);
459 keysv = newSVsv(keysv);
462 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
464 /* grab a fake HE/HEK pair from the pool or make a new one */
465 entry = PL_hv_fetch_ent_mh;
467 PL_hv_fetch_ent_mh = HeNEXT(entry);
471 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
472 HeKEY_hek(entry) = (HEK*)k;
474 HeNEXT(entry) = NULL;
475 HeSVKEY_set(entry, keysv);
477 sv_upgrade(sv, SVt_PVLV);
479 /* so we can free entry when freeing sv */
480 LvTARG(sv) = (SV*)entry;
482 /* XXX remove at some point? */
483 if (flags & HVhek_FREEKEY)
488 #ifdef ENV_IS_CASELESS
489 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
491 for (i = 0; i < klen; ++i)
492 if (isLOWER(key[i])) {
493 /* Would be nice if we had a routine to do the
494 copy and upercase in a single pass through. */
495 const char * const nkey = strupr(savepvn(key,klen));
496 /* Note that this fetch is for nkey (the uppercased
497 key) whereas the store is for key (the original) */
498 entry = hv_fetch_common(hv, NULL, nkey, klen,
499 HVhek_FREEKEY, /* free nkey */
500 0 /* non-LVAL fetch */
501 | HV_DISABLE_UVAR_XKEY,
503 0 /* compute hash */);
504 if (!entry && (action & HV_FETCH_LVALUE)) {
505 /* This call will free key if necessary.
506 Do it this way to encourage compiler to tail
508 entry = hv_fetch_common(hv, keysv, key, klen,
511 | HV_DISABLE_UVAR_XKEY,
514 if (flags & HVhek_FREEKEY)
522 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
523 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
524 /* I don't understand why hv_exists_ent has svret and sv,
525 whereas hv_exists only had one. */
526 SV * const svret = sv_newmortal();
529 if (keysv || is_utf8) {
531 keysv = newSVpvn(key, klen);
534 keysv = newSVsv(keysv);
536 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
538 mg_copy((SV*)hv, sv, key, klen);
540 if (flags & HVhek_FREEKEY)
542 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
543 /* This cast somewhat evil, but I'm merely using NULL/
544 not NULL to return the boolean exists.
545 And I know hv is not NULL. */
546 return SvTRUE(svret) ? (HE *)hv : NULL;
548 #ifdef ENV_IS_CASELESS
549 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
550 /* XXX This code isn't UTF8 clean. */
551 char * const keysave = (char * const)key;
552 /* Will need to free this, so set FREEKEY flag. */
553 key = savepvn(key,klen);
554 key = (const char*)strupr((char*)key);
559 if (flags & HVhek_FREEKEY) {
562 flags |= HVhek_FREEKEY;
566 else if (action & HV_FETCH_ISSTORE) {
569 hv_magic_check (hv, &needs_copy, &needs_store);
571 const bool save_taint = PL_tainted;
572 if (keysv || is_utf8) {
574 keysv = newSVpvn(key, klen);
578 PL_tainted = SvTAINTED(keysv);
579 keysv = sv_2mortal(newSVsv(keysv));
580 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
582 mg_copy((SV*)hv, val, key, klen);
585 TAINT_IF(save_taint);
587 if (flags & HVhek_FREEKEY)
591 #ifdef ENV_IS_CASELESS
592 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
593 /* XXX This code isn't UTF8 clean. */
594 const char *keysave = key;
595 /* Will need to free this, so set FREEKEY flag. */
596 key = savepvn(key,klen);
597 key = (const char*)strupr((char*)key);
602 if (flags & HVhek_FREEKEY) {
605 flags |= HVhek_FREEKEY;
613 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
614 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
615 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
620 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
622 HvARRAY(hv) = (HE**)array;
624 #ifdef DYNAMIC_ENV_FETCH
625 else if (action & HV_FETCH_ISEXISTS) {
626 /* for an %ENV exists, if we do an insert it's by a recursive
627 store call, so avoid creating HvARRAY(hv) right now. */
631 /* XXX remove at some point? */
632 if (flags & HVhek_FREEKEY)
640 char * const keysave = (char *)key;
641 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
645 flags &= ~HVhek_UTF8;
646 if (key != keysave) {
647 if (flags & HVhek_FREEKEY)
649 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
654 PERL_HASH_INTERNAL(hash, key, klen);
655 /* We don't have a pointer to the hv, so we have to replicate the
656 flag into every HEK, so that hv_iterkeysv can see it. */
657 /* And yes, you do need this even though you are not "storing" because
658 you can flip the flags below if doing an lval lookup. (And that
659 was put in to give the semantics Andreas was expecting.) */
660 flags |= HVhek_REHASH;
662 if (keysv && (SvIsCOW_shared_hash(keysv))) {
663 hash = SvSHARED_HASH(keysv);
665 PERL_HASH(hash, key, klen);
669 masked_flags = (flags & HVhek_MASK);
671 #ifdef DYNAMIC_ENV_FETCH
672 if (!HvARRAY(hv)) entry = NULL;
676 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
678 for (; entry; entry = HeNEXT(entry)) {
679 if (HeHASH(entry) != hash) /* strings can't be equal */
681 if (HeKLEN(entry) != (I32)klen)
683 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
685 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
688 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
689 if (HeKFLAGS(entry) != masked_flags) {
690 /* We match if HVhek_UTF8 bit in our flags and hash key's
691 match. But if entry was set previously with HVhek_WASUTF8
692 and key now doesn't (or vice versa) then we should change
693 the key's flag, as this is assignment. */
694 if (HvSHAREKEYS(hv)) {
695 /* Need to swap the key we have for a key with the flags we
696 need. As keys are shared we can't just write to the
697 flag, so we share the new one, unshare the old one. */
698 HEK * const new_hek = share_hek_flags(key, klen, hash,
700 unshare_hek (HeKEY_hek(entry));
701 HeKEY_hek(entry) = new_hek;
703 else if (hv == PL_strtab) {
704 /* PL_strtab is usually the only hash without HvSHAREKEYS,
705 so putting this test here is cheap */
706 if (flags & HVhek_FREEKEY)
708 Perl_croak(aTHX_ S_strtab_error,
709 action & HV_FETCH_LVALUE ? "fetch" : "store");
712 HeKFLAGS(entry) = masked_flags;
713 if (masked_flags & HVhek_ENABLEHVKFLAGS)
716 if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* yes, can store into placeholder slot */
718 if (action & HV_FETCH_LVALUE) {
720 /* This preserves behaviour with the old hv_fetch
721 implementation which at this point would bail out
722 with a break; (at "if we find a placeholder, we
723 pretend we haven't found anything")
725 That break mean that if a placeholder were found, it
726 caused a call into hv_store, which in turn would
727 check magic, and if there is no magic end up pretty
728 much back at this point (in hv_store's code). */
731 /* LVAL fetch which actaully needs a store. */
733 HvPLACEHOLDERS(hv)--;
736 if (val != &PL_sv_placeholder)
737 HvPLACEHOLDERS(hv)--;
740 } else if (action & HV_FETCH_ISSTORE) {
741 SvREFCNT_dec(HeVAL(entry));
744 } else if (HeVAL(entry) == &PL_sv_placeholder) {
745 /* if we find a placeholder, we pretend we haven't found
749 if (flags & HVhek_FREEKEY)
753 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
754 if (!(action & HV_FETCH_ISSTORE)
755 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
757 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
759 sv = newSVpvn(env,len);
761 return hv_fetch_common(hv, keysv, key, klen, flags,
762 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, sv,
768 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
769 hv_notallowed(flags, key, klen,
770 "Attempt to access disallowed key '%"SVf"' in"
771 " a restricted hash");
773 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
774 /* Not doing some form of store, so return failure. */
775 if (flags & HVhek_FREEKEY)
779 if (action & HV_FETCH_LVALUE) {
782 /* At this point the old hv_fetch code would call to hv_store,
783 which in turn might do some tied magic. So we need to make that
784 magic check happen. */
785 /* gonna assign to this, so it better be there */
786 return hv_fetch_common(hv, keysv, key, klen, flags,
787 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, val,
789 /* XXX Surely that could leak if the fetch-was-store fails?
790 Just like the hv_fetch. */
794 /* Welcome to hv_store... */
797 /* Not sure if we can get here. I think the only case of oentry being
798 NULL is for %ENV with dynamic env fetch. But that should disappear
799 with magic in the previous code. */
802 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
804 HvARRAY(hv) = (HE**)array;
807 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
810 /* share_hek_flags will do the free for us. This might be considered
813 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
814 else if (hv == PL_strtab) {
815 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
816 this test here is cheap */
817 if (flags & HVhek_FREEKEY)
819 Perl_croak(aTHX_ S_strtab_error,
820 action & HV_FETCH_LVALUE ? "fetch" : "store");
822 else /* gotta do the real thing */
823 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
825 HeNEXT(entry) = *oentry;
828 if (val == &PL_sv_placeholder)
829 HvPLACEHOLDERS(hv)++;
830 if (masked_flags & HVhek_ENABLEHVKFLAGS)
834 const HE *counter = HeNEXT(entry);
836 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
837 if (!counter) { /* initial entry? */
838 xhv->xhv_fill++; /* HvFILL(hv)++ */
839 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
841 } else if(!HvREHASH(hv)) {
844 while ((counter = HeNEXT(counter)))
847 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
848 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
849 bucket splits on a rehashed hash, as we're not going to
850 split it again, and if someone is lucky (evil) enough to
851 get all the keys in one list they could exhaust our memory
852 as we repeatedly double the number of buckets on every
853 entry. Linear search feels a less worse thing to do. */
863 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
865 const MAGIC *mg = SvMAGIC(hv);
869 if (isUPPER(mg->mg_type)) {
871 if (mg->mg_type == PERL_MAGIC_tied) {
872 *needs_store = FALSE;
873 return; /* We've set all there is to set. */
876 mg = mg->mg_moremagic;
881 =for apidoc hv_scalar
883 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
889 Perl_hv_scalar(pTHX_ HV *hv)
893 if (SvRMAGICAL(hv)) {
894 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
896 return magic_scalarpack(hv, mg);
901 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
902 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
910 =for apidoc hv_delete
912 Deletes a key/value pair in the hash. The value SV is removed from the
913 hash and returned to the caller. The C<klen> is the length of the key.
914 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
921 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
928 k_flags = HVhek_UTF8;
933 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
937 =for apidoc hv_delete_ent
939 Deletes a key/value pair in the hash. The value SV is removed from the
940 hash and returned to the caller. The C<flags> value will normally be zero;
941 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
942 precomputed hash value, or 0 to ask for it to be computed.
947 /* XXX This looks like an ideal candidate to inline */
949 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
951 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
955 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
956 int k_flags, I32 d_flags, U32 hash)
961 register HE **oentry;
962 HE *const *first_entry;
970 if (SvSMAGICAL(hv) && SvGMAGICAL(hv)
971 && !(d_flags & HV_DISABLE_UVAR_XKEY))
972 keysv = hv_magic_uvar_xkey(hv, keysv, HV_DELETE);
973 if (k_flags & HVhek_FREEKEY)
975 key = SvPV_const(keysv, klen);
977 is_utf8 = (SvUTF8(keysv) != 0);
979 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
982 if (SvRMAGICAL(hv)) {
985 hv_magic_check (hv, &needs_copy, &needs_store);
989 entry = hv_fetch_common(hv, keysv, key, klen,
990 k_flags & ~HVhek_FREEKEY,
991 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
993 sv = entry ? HeVAL(entry) : NULL;
999 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1000 /* No longer an element */
1001 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1004 return NULL; /* element cannot be deleted */
1006 #ifdef ENV_IS_CASELESS
1007 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1008 /* XXX This code isn't UTF8 clean. */
1009 keysv = sv_2mortal(newSVpvn(key,klen));
1010 if (k_flags & HVhek_FREEKEY) {
1013 key = strupr(SvPVX(keysv));
1022 xhv = (XPVHV*)SvANY(hv);
1027 const char * const keysave = key;
1028 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1031 k_flags |= HVhek_UTF8;
1033 k_flags &= ~HVhek_UTF8;
1034 if (key != keysave) {
1035 if (k_flags & HVhek_FREEKEY) {
1036 /* This shouldn't happen if our caller does what we expect,
1037 but strictly the API allows it. */
1040 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1042 HvHASKFLAGS_on((SV*)hv);
1046 PERL_HASH_INTERNAL(hash, key, klen);
1048 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1049 hash = SvSHARED_HASH(keysv);
1051 PERL_HASH(hash, key, klen);
1055 masked_flags = (k_flags & HVhek_MASK);
1057 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1059 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1061 if (HeHASH(entry) != hash) /* strings can't be equal */
1063 if (HeKLEN(entry) != (I32)klen)
1065 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1067 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1070 if (hv == PL_strtab) {
1071 if (k_flags & HVhek_FREEKEY)
1073 Perl_croak(aTHX_ S_strtab_error, "delete");
1076 /* if placeholder is here, it's already been deleted.... */
1077 if (HeVAL(entry) == &PL_sv_placeholder) {
1078 if (k_flags & HVhek_FREEKEY)
1082 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1083 hv_notallowed(k_flags, key, klen,
1084 "Attempt to delete readonly key '%"SVf"' from"
1085 " a restricted hash");
1087 if (k_flags & HVhek_FREEKEY)
1090 if (d_flags & G_DISCARD)
1093 sv = sv_2mortal(HeVAL(entry));
1094 HeVAL(entry) = &PL_sv_placeholder;
1098 * If a restricted hash, rather than really deleting the entry, put
1099 * a placeholder there. This marks the key as being "approved", so
1100 * we can still access via not-really-existing key without raising
1103 if (SvREADONLY(hv)) {
1104 SvREFCNT_dec(HeVAL(entry));
1105 HeVAL(entry) = &PL_sv_placeholder;
1106 /* We'll be saving this slot, so the number of allocated keys
1107 * doesn't go down, but the number placeholders goes up */
1108 HvPLACEHOLDERS(hv)++;
1110 *oentry = HeNEXT(entry);
1112 xhv->xhv_fill--; /* HvFILL(hv)-- */
1114 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1117 hv_free_ent(hv, entry);
1118 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1119 if (xhv->xhv_keys == 0)
1120 HvHASKFLAGS_off(hv);
1124 if (SvREADONLY(hv)) {
1125 hv_notallowed(k_flags, key, klen,
1126 "Attempt to delete disallowed key '%"SVf"' from"
1127 " a restricted hash");
1130 if (k_flags & HVhek_FREEKEY)
1136 S_hsplit(pTHX_ HV *hv)
1139 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1140 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1141 register I32 newsize = oldsize * 2;
1143 char *a = (char*) HvARRAY(hv);
1145 register HE **oentry;
1146 int longest_chain = 0;
1149 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1150 (void*)hv, (int) oldsize);*/
1152 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1153 /* Can make this clear any placeholders first for non-restricted hashes,
1154 even though Storable rebuilds restricted hashes by putting in all the
1155 placeholders (first) before turning on the readonly flag, because
1156 Storable always pre-splits the hash. */
1157 hv_clear_placeholders(hv);
1161 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1162 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1163 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1169 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1172 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1173 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1178 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1180 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1182 if (oldsize >= 64) {
1183 offer_nice_chunk(HvARRAY(hv),
1184 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1185 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1188 Safefree(HvARRAY(hv));
1192 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1193 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1194 HvARRAY(hv) = (HE**) a;
1197 for (i=0; i<oldsize; i++,aep++) {
1198 int left_length = 0;
1199 int right_length = 0;
1203 if (!*aep) /* non-existent */
1206 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1207 if ((HeHASH(entry) & newsize) != (U32)i) {
1208 *oentry = HeNEXT(entry);
1209 HeNEXT(entry) = *bep;
1211 xhv->xhv_fill++; /* HvFILL(hv)++ */
1217 oentry = &HeNEXT(entry);
1221 if (!*aep) /* everything moved */
1222 xhv->xhv_fill--; /* HvFILL(hv)-- */
1223 /* I think we don't actually need to keep track of the longest length,
1224 merely flag if anything is too long. But for the moment while
1225 developing this code I'll track it. */
1226 if (left_length > longest_chain)
1227 longest_chain = left_length;
1228 if (right_length > longest_chain)
1229 longest_chain = right_length;
1233 /* Pick your policy for "hashing isn't working" here: */
1234 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1239 if (hv == PL_strtab) {
1240 /* Urg. Someone is doing something nasty to the string table.
1245 /* Awooga. Awooga. Pathological data. */
1246 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1247 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1250 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1251 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1253 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1256 was_shared = HvSHAREKEYS(hv);
1259 HvSHAREKEYS_off(hv);
1264 for (i=0; i<newsize; i++,aep++) {
1265 register HE *entry = *aep;
1267 /* We're going to trash this HE's next pointer when we chain it
1268 into the new hash below, so store where we go next. */
1269 HE * const next = HeNEXT(entry);
1274 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1279 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1280 hash, HeKFLAGS(entry));
1281 unshare_hek (HeKEY_hek(entry));
1282 HeKEY_hek(entry) = new_hek;
1284 /* Not shared, so simply write the new hash in. */
1285 HeHASH(entry) = hash;
1287 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1288 HEK_REHASH_on(HeKEY_hek(entry));
1289 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1291 /* Copy oentry to the correct new chain. */
1292 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1294 xhv->xhv_fill++; /* HvFILL(hv)++ */
1295 HeNEXT(entry) = *bep;
1301 Safefree (HvARRAY(hv));
1302 HvARRAY(hv) = (HE **)a;
1306 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1309 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1310 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1311 register I32 newsize;
1316 register HE **oentry;
1318 newsize = (I32) newmax; /* possible truncation here */
1319 if (newsize != newmax || newmax <= oldsize)
1321 while ((newsize & (1 + ~newsize)) != newsize) {
1322 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1324 if (newsize < newmax)
1326 if (newsize < newmax)
1327 return; /* overflow detection */
1329 a = (char *) HvARRAY(hv);
1332 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1333 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1334 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1340 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1343 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1344 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1349 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1351 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1353 if (oldsize >= 64) {
1354 offer_nice_chunk(HvARRAY(hv),
1355 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1356 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1359 Safefree(HvARRAY(hv));
1362 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1365 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1367 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1368 HvARRAY(hv) = (HE **) a;
1369 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1373 for (i=0; i<oldsize; i++,aep++) {
1374 if (!*aep) /* non-existent */
1376 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1377 register I32 j = (HeHASH(entry) & newsize);
1381 *oentry = HeNEXT(entry);
1382 if (!(HeNEXT(entry) = aep[j]))
1383 xhv->xhv_fill++; /* HvFILL(hv)++ */
1388 oentry = &HeNEXT(entry);
1390 if (!*aep) /* everything moved */
1391 xhv->xhv_fill--; /* HvFILL(hv)-- */
1398 Creates a new HV. The reference count is set to 1.
1406 register XPVHV* xhv;
1407 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1408 xhv = (XPVHV*)SvANY(hv);
1410 #ifndef NODEFAULT_SHAREKEYS
1411 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1414 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1415 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1420 Perl_newHVhv(pTHX_ HV *ohv)
1422 HV * const hv = newHV();
1423 STRLEN hv_max, hv_fill;
1425 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1427 hv_max = HvMAX(ohv);
1429 if (!SvMAGICAL((SV *)ohv)) {
1430 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1432 const bool shared = !!HvSHAREKEYS(ohv);
1433 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1435 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1438 /* In each bucket... */
1439 for (i = 0; i <= hv_max; i++) {
1441 HE *oent = oents[i];
1448 /* Copy the linked list of entries. */
1449 for (; oent; oent = HeNEXT(oent)) {
1450 const U32 hash = HeHASH(oent);
1451 const char * const key = HeKEY(oent);
1452 const STRLEN len = HeKLEN(oent);
1453 const int flags = HeKFLAGS(oent);
1454 HE * const ent = new_HE();
1456 HeVAL(ent) = newSVsv(HeVAL(oent));
1458 = shared ? share_hek_flags(key, len, hash, flags)
1459 : save_hek_flags(key, len, hash, flags);
1470 HvFILL(hv) = hv_fill;
1471 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1475 /* Iterate over ohv, copying keys and values one at a time. */
1477 const I32 riter = HvRITER_get(ohv);
1478 HE * const eiter = HvEITER_get(ohv);
1480 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1481 while (hv_max && hv_max + 1 >= hv_fill * 2)
1482 hv_max = hv_max / 2;
1486 while ((entry = hv_iternext_flags(ohv, 0))) {
1487 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1488 newSVsv(HeVAL(entry)), HeHASH(entry),
1491 HvRITER_set(ohv, riter);
1492 HvEITER_set(ohv, eiter);
1498 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1499 magic stays on it. */
1501 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1503 HV * const hv = newHV();
1506 if (ohv && (hv_fill = HvFILL(ohv))) {
1507 STRLEN hv_max = HvMAX(ohv);
1509 const I32 riter = HvRITER_get(ohv);
1510 HE * const eiter = HvEITER_get(ohv);
1512 while (hv_max && hv_max + 1 >= hv_fill * 2)
1513 hv_max = hv_max / 2;
1517 while ((entry = hv_iternext_flags(ohv, 0))) {
1518 SV *const sv = newSVsv(HeVAL(entry));
1519 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1520 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1521 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1522 sv, HeHASH(entry), HeKFLAGS(entry));
1524 HvRITER_set(ohv, riter);
1525 HvEITER_set(ohv, eiter);
1527 hv_magic(hv, NULL, PERL_MAGIC_hints);
1532 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1540 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1541 mro_method_changed_in(hv); /* deletion of method from stash */
1543 if (HeKLEN(entry) == HEf_SVKEY) {
1544 SvREFCNT_dec(HeKEY_sv(entry));
1545 Safefree(HeKEY_hek(entry));
1547 else if (HvSHAREKEYS(hv))
1548 unshare_hek(HeKEY_hek(entry));
1550 Safefree(HeKEY_hek(entry));
1555 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1560 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1561 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1562 if (HeKLEN(entry) == HEf_SVKEY) {
1563 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1565 hv_free_ent(hv, entry);
1569 =for apidoc hv_clear
1571 Clears a hash, making it empty.
1577 Perl_hv_clear(pTHX_ HV *hv)
1580 register XPVHV* xhv;
1584 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1586 xhv = (XPVHV*)SvANY(hv);
1588 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1589 /* restricted hash: convert all keys to placeholders */
1591 for (i = 0; i <= xhv->xhv_max; i++) {
1592 HE *entry = (HvARRAY(hv))[i];
1593 for (; entry; entry = HeNEXT(entry)) {
1594 /* not already placeholder */
1595 if (HeVAL(entry) != &PL_sv_placeholder) {
1596 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1597 SV* const keysv = hv_iterkeysv(entry);
1599 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1602 SvREFCNT_dec(HeVAL(entry));
1603 HeVAL(entry) = &PL_sv_placeholder;
1604 HvPLACEHOLDERS(hv)++;
1612 HvPLACEHOLDERS_set(hv, 0);
1614 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1619 HvHASKFLAGS_off(hv);
1624 mro_isa_changed_in(hv);
1625 HvEITER_set(hv, NULL);
1630 =for apidoc hv_clear_placeholders
1632 Clears any placeholders from a hash. If a restricted hash has any of its keys
1633 marked as readonly and the key is subsequently deleted, the key is not actually
1634 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1635 it so it will be ignored by future operations such as iterating over the hash,
1636 but will still allow the hash to have a value reassigned to the key at some
1637 future point. This function clears any such placeholder keys from the hash.
1638 See Hash::Util::lock_keys() for an example of its use.
1644 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1647 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1650 clear_placeholders(hv, items);
1654 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1664 /* Loop down the linked list heads */
1666 HE **oentry = &(HvARRAY(hv))[i];
1669 while ((entry = *oentry)) {
1670 if (HeVAL(entry) == &PL_sv_placeholder) {
1671 *oentry = HeNEXT(entry);
1672 if (first && !*oentry)
1673 HvFILL(hv)--; /* This linked list is now empty. */
1674 if (entry == HvEITER_get(hv))
1677 hv_free_ent(hv, entry);
1681 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1682 if (HvKEYS(hv) == 0)
1683 HvHASKFLAGS_off(hv);
1684 HvPLACEHOLDERS_set(hv, 0);
1688 oentry = &HeNEXT(entry);
1693 /* You can't get here, hence assertion should always fail. */
1694 assert (items == 0);
1699 S_hfreeentries(pTHX_ HV *hv)
1701 /* This is the array that we're going to restore */
1702 HE **const orig_array = HvARRAY(hv);
1710 /* If the hash is actually a symbol table with a name, look after the
1712 struct xpvhv_aux *iter = HvAUX(hv);
1714 name = iter->xhv_name;
1715 iter->xhv_name = NULL;
1720 /* orig_array remains unchanged throughout the loop. If after freeing all
1721 the entries it turns out that one of the little blighters has triggered
1722 an action that has caused HvARRAY to be re-allocated, then we set
1723 array to the new HvARRAY, and try again. */
1726 /* This is the one we're going to try to empty. First time round
1727 it's the original array. (Hopefully there will only be 1 time
1729 HE ** const array = HvARRAY(hv);
1732 /* Because we have taken xhv_name out, the only allocated pointer
1733 in the aux structure that might exist is the backreference array.
1738 struct mro_meta *meta;
1739 struct xpvhv_aux *iter = HvAUX(hv);
1740 /* If there are weak references to this HV, we need to avoid
1741 freeing them up here. In particular we need to keep the AV
1742 visible as what we're deleting might well have weak references
1743 back to this HV, so the for loop below may well trigger
1744 the removal of backreferences from this array. */
1746 if (iter->xhv_backreferences) {
1747 /* So donate them to regular backref magic to keep them safe.
1748 The sv_magic will increase the reference count of the AV,
1749 so we need to drop it first. */
1750 SvREFCNT_dec(iter->xhv_backreferences);
1751 if (AvFILLp(iter->xhv_backreferences) == -1) {
1752 /* Turns out that the array is empty. Just free it. */
1753 SvREFCNT_dec(iter->xhv_backreferences);
1756 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1757 PERL_MAGIC_backref, NULL, 0);
1759 iter->xhv_backreferences = NULL;
1762 entry = iter->xhv_eiter; /* HvEITER(hv) */
1763 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1765 hv_free_ent(hv, entry);
1767 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1768 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1770 if((meta = iter->xhv_mro_meta)) {
1771 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1772 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1773 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1775 iter->xhv_mro_meta = NULL;
1778 /* There are now no allocated pointers in the aux structure. */
1780 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1781 /* What aux structure? */
1784 /* make everyone else think the array is empty, so that the destructors
1785 * called for freed entries can't recusively mess with us */
1788 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1792 /* Loop down the linked list heads */
1793 HE *entry = array[i];
1796 register HE * const oentry = entry;
1797 entry = HeNEXT(entry);
1798 hv_free_ent(hv, oentry);
1802 /* As there are no allocated pointers in the aux structure, it's now
1803 safe to free the array we just cleaned up, if it's not the one we're
1804 going to put back. */
1805 if (array != orig_array) {
1810 /* Good. No-one added anything this time round. */
1815 /* Someone attempted to iterate or set the hash name while we had
1816 the array set to 0. We'll catch backferences on the next time
1817 round the while loop. */
1818 assert(HvARRAY(hv));
1820 if (HvAUX(hv)->xhv_name) {
1821 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1825 if (--attempts == 0) {
1826 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1830 HvARRAY(hv) = orig_array;
1832 /* If the hash was actually a symbol table, put the name back. */
1834 /* We have restored the original array. If name is non-NULL, then
1835 the original array had an aux structure at the end. So this is
1837 SvFLAGS(hv) |= SVf_OOK;
1838 HvAUX(hv)->xhv_name = name;
1843 =for apidoc hv_undef
1851 Perl_hv_undef(pTHX_ HV *hv)
1854 register XPVHV* xhv;
1859 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1860 xhv = (XPVHV*)SvANY(hv);
1862 if ((name = HvNAME_get(hv)) && !PL_dirty)
1863 mro_isa_changed_in(hv);
1868 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1869 hv_name_set(hv, NULL, 0, 0);
1871 SvFLAGS(hv) &= ~SVf_OOK;
1872 Safefree(HvARRAY(hv));
1873 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1875 HvPLACEHOLDERS_set(hv, 0);
1881 static struct xpvhv_aux*
1882 S_hv_auxinit(HV *hv) {
1883 struct xpvhv_aux *iter;
1887 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1888 + sizeof(struct xpvhv_aux), char);
1890 array = (char *) HvARRAY(hv);
1891 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1892 + sizeof(struct xpvhv_aux), char);
1894 HvARRAY(hv) = (HE**) array;
1895 /* SvOOK_on(hv) attacks the IV flags. */
1896 SvFLAGS(hv) |= SVf_OOK;
1899 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1900 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1902 iter->xhv_backreferences = 0;
1903 iter->xhv_mro_meta = NULL;
1908 =for apidoc hv_iterinit
1910 Prepares a starting point to traverse a hash table. Returns the number of
1911 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1912 currently only meaningful for hashes without tie magic.
1914 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1915 hash buckets that happen to be in use. If you still need that esoteric
1916 value, you can get it through the macro C<HvFILL(tb)>.
1923 Perl_hv_iterinit(pTHX_ HV *hv)
1926 Perl_croak(aTHX_ "Bad hash");
1929 struct xpvhv_aux * const iter = HvAUX(hv);
1930 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1931 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1933 hv_free_ent(hv, entry);
1935 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1936 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1941 /* used to be xhv->xhv_fill before 5.004_65 */
1942 return HvTOTALKEYS(hv);
1946 Perl_hv_riter_p(pTHX_ HV *hv) {
1947 struct xpvhv_aux *iter;
1950 Perl_croak(aTHX_ "Bad hash");
1952 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1953 return &(iter->xhv_riter);
1957 Perl_hv_eiter_p(pTHX_ HV *hv) {
1958 struct xpvhv_aux *iter;
1961 Perl_croak(aTHX_ "Bad hash");
1963 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1964 return &(iter->xhv_eiter);
1968 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1969 struct xpvhv_aux *iter;
1972 Perl_croak(aTHX_ "Bad hash");
1980 iter = hv_auxinit(hv);
1982 iter->xhv_riter = riter;
1986 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1987 struct xpvhv_aux *iter;
1990 Perl_croak(aTHX_ "Bad hash");
1995 /* 0 is the default so don't go malloc()ing a new structure just to
2000 iter = hv_auxinit(hv);
2002 iter->xhv_eiter = eiter;
2006 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2009 struct xpvhv_aux *iter;
2012 PERL_UNUSED_ARG(flags);
2015 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2019 if (iter->xhv_name) {
2020 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2026 iter = hv_auxinit(hv);
2028 PERL_HASH(hash, name, len);
2029 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2033 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2034 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2035 PERL_UNUSED_CONTEXT;
2036 return &(iter->xhv_backreferences);
2040 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2046 av = HvAUX(hv)->xhv_backreferences;
2049 HvAUX(hv)->xhv_backreferences = 0;
2050 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2055 hv_iternext is implemented as a macro in hv.h
2057 =for apidoc hv_iternext
2059 Returns entries from a hash iterator. See C<hv_iterinit>.
2061 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2062 iterator currently points to, without losing your place or invalidating your
2063 iterator. Note that in this case the current entry is deleted from the hash
2064 with your iterator holding the last reference to it. Your iterator is flagged
2065 to free the entry on the next call to C<hv_iternext>, so you must not discard
2066 your iterator immediately else the entry will leak - call C<hv_iternext> to
2067 trigger the resource deallocation.
2069 =for apidoc hv_iternext_flags
2071 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2072 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2073 set the placeholders keys (for restricted hashes) will be returned in addition
2074 to normal keys. By default placeholders are automatically skipped over.
2075 Currently a placeholder is implemented with a value that is
2076 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2077 restricted hashes may change, and the implementation currently is
2078 insufficiently abstracted for any change to be tidy.
2084 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2087 register XPVHV* xhv;
2091 struct xpvhv_aux *iter;
2094 Perl_croak(aTHX_ "Bad hash");
2096 xhv = (XPVHV*)SvANY(hv);
2099 /* Too many things (well, pp_each at least) merrily assume that you can
2100 call iv_iternext without calling hv_iterinit, so we'll have to deal
2106 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2107 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2108 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2109 SV * const key = sv_newmortal();
2111 sv_setsv(key, HeSVKEY_force(entry));
2112 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2118 /* one HE per MAGICAL hash */
2119 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2121 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2123 HeKEY_hek(entry) = hek;
2124 HeKLEN(entry) = HEf_SVKEY;
2126 magic_nextpack((SV*) hv,mg,key);
2128 /* force key to stay around until next time */
2129 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2130 return entry; /* beware, hent_val is not set */
2133 SvREFCNT_dec(HeVAL(entry));
2134 Safefree(HeKEY_hek(entry));
2136 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2140 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2141 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2144 /* The prime_env_iter() on VMS just loaded up new hash values
2145 * so the iteration count needs to be reset back to the beginning
2149 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2154 /* hv_iterint now ensures this. */
2155 assert (HvARRAY(hv));
2157 /* At start of hash, entry is NULL. */
2160 entry = HeNEXT(entry);
2161 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2163 * Skip past any placeholders -- don't want to include them in
2166 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2167 entry = HeNEXT(entry);
2172 /* OK. Come to the end of the current list. Grab the next one. */
2174 iter->xhv_riter++; /* HvRITER(hv)++ */
2175 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2176 /* There is no next one. End of the hash. */
2177 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2180 entry = (HvARRAY(hv))[iter->xhv_riter];
2182 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2183 /* If we have an entry, but it's a placeholder, don't count it.
2185 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2186 entry = HeNEXT(entry);
2188 /* Will loop again if this linked list starts NULL
2189 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2190 or if we run through it and find only placeholders. */
2193 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2195 hv_free_ent(hv, oldentry);
2198 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2199 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2201 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2206 =for apidoc hv_iterkey
2208 Returns the key from the current position of the hash iterator. See
2215 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2217 if (HeKLEN(entry) == HEf_SVKEY) {
2219 char * const p = SvPV(HeKEY_sv(entry), len);
2224 *retlen = HeKLEN(entry);
2225 return HeKEY(entry);
2229 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2231 =for apidoc hv_iterkeysv
2233 Returns the key as an C<SV*> from the current position of the hash
2234 iterator. The return value will always be a mortal copy of the key. Also
2241 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2243 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2247 =for apidoc hv_iterval
2249 Returns the value from the current position of the hash iterator. See
2256 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2258 if (SvRMAGICAL(hv)) {
2259 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2260 SV* const sv = sv_newmortal();
2261 if (HeKLEN(entry) == HEf_SVKEY)
2262 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2264 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2268 return HeVAL(entry);
2272 =for apidoc hv_iternextsv
2274 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2281 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2283 HE * const he = hv_iternext_flags(hv, 0);
2287 *key = hv_iterkey(he, retlen);
2288 return hv_iterval(hv, he);
2295 =for apidoc hv_magic
2297 Adds magic to a hash. See C<sv_magic>.
2302 /* possibly free a shared string if no one has access to it
2303 * len and hash must both be valid for str.
2306 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2308 unshare_hek_or_pvn (NULL, str, len, hash);
2313 Perl_unshare_hek(pTHX_ HEK *hek)
2316 unshare_hek_or_pvn(hek, NULL, 0, 0);
2319 /* possibly free a shared string if no one has access to it
2320 hek if non-NULL takes priority over the other 3, else str, len and hash
2321 are used. If so, len and hash must both be valid for str.
2324 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2327 register XPVHV* xhv;
2329 register HE **oentry;
2331 bool is_utf8 = FALSE;
2333 const char * const save = str;
2334 struct shared_he *he = NULL;
2337 /* Find the shared he which is just before us in memory. */
2338 he = (struct shared_he *)(((char *)hek)
2339 - STRUCT_OFFSET(struct shared_he,
2342 /* Assert that the caller passed us a genuine (or at least consistent)
2344 assert (he->shared_he_he.hent_hek == hek);
2347 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2348 --he->shared_he_he.he_valu.hent_refcount;
2349 UNLOCK_STRTAB_MUTEX;
2352 UNLOCK_STRTAB_MUTEX;
2354 hash = HEK_HASH(hek);
2355 } else if (len < 0) {
2356 STRLEN tmplen = -len;
2358 /* See the note in hv_fetch(). --jhi */
2359 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2362 k_flags = HVhek_UTF8;
2364 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2367 /* what follows was the moral equivalent of:
2368 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2370 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2372 xhv = (XPVHV*)SvANY(PL_strtab);
2373 /* assert(xhv_array != 0) */
2375 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2377 const HE *const he_he = &(he->shared_he_he);
2378 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2383 const int flags_masked = k_flags & HVhek_MASK;
2384 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2385 if (HeHASH(entry) != hash) /* strings can't be equal */
2387 if (HeKLEN(entry) != len)
2389 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2391 if (HeKFLAGS(entry) != flags_masked)
2398 if (--entry->he_valu.hent_refcount == 0) {
2399 *oentry = HeNEXT(entry);
2401 /* There are now no entries in our slot. */
2402 xhv->xhv_fill--; /* HvFILL(hv)-- */
2405 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2409 UNLOCK_STRTAB_MUTEX;
2410 if (!entry && ckWARN_d(WARN_INTERNAL))
2411 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2412 "Attempt to free non-existent shared string '%s'%s"
2414 hek ? HEK_KEY(hek) : str,
2415 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2416 if (k_flags & HVhek_FREEKEY)
2420 /* get a (constant) string ptr from the global string table
2421 * string will get added if it is not already there.
2422 * len and hash must both be valid for str.
2425 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2427 bool is_utf8 = FALSE;
2429 const char * const save = str;
2432 STRLEN tmplen = -len;
2434 /* See the note in hv_fetch(). --jhi */
2435 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2437 /* If we were able to downgrade here, then than means that we were passed
2438 in a key which only had chars 0-255, but was utf8 encoded. */
2441 /* If we found we were able to downgrade the string to bytes, then
2442 we should flag that it needs upgrading on keys or each. Also flag
2443 that we need share_hek_flags to free the string. */
2445 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2448 return share_hek_flags (str, len, hash, flags);
2452 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2456 const int flags_masked = flags & HVhek_MASK;
2457 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2459 /* what follows is the moral equivalent of:
2461 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2462 hv_store(PL_strtab, str, len, NULL, hash);
2464 Can't rehash the shared string table, so not sure if it's worth
2465 counting the number of entries in the linked list
2467 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2468 /* assert(xhv_array != 0) */
2470 entry = (HvARRAY(PL_strtab))[hindex];
2471 for (;entry; entry = HeNEXT(entry)) {
2472 if (HeHASH(entry) != hash) /* strings can't be equal */
2474 if (HeKLEN(entry) != len)
2476 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2478 if (HeKFLAGS(entry) != flags_masked)
2484 /* What used to be head of the list.
2485 If this is NULL, then we're the first entry for this slot, which
2486 means we need to increate fill. */
2487 struct shared_he *new_entry;
2490 HE **const head = &HvARRAY(PL_strtab)[hindex];
2491 HE *const next = *head;
2493 /* We don't actually store a HE from the arena and a regular HEK.
2494 Instead we allocate one chunk of memory big enough for both,
2495 and put the HEK straight after the HE. This way we can find the
2496 HEK directly from the HE.
2499 Newx(k, STRUCT_OFFSET(struct shared_he,
2500 shared_he_hek.hek_key[0]) + len + 2, char);
2501 new_entry = (struct shared_he *)k;
2502 entry = &(new_entry->shared_he_he);
2503 hek = &(new_entry->shared_he_hek);
2505 Copy(str, HEK_KEY(hek), len, char);
2506 HEK_KEY(hek)[len] = 0;
2508 HEK_HASH(hek) = hash;
2509 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2511 /* Still "point" to the HEK, so that other code need not know what
2513 HeKEY_hek(entry) = hek;
2514 entry->he_valu.hent_refcount = 0;
2515 HeNEXT(entry) = next;
2518 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2519 if (!next) { /* initial entry? */
2520 xhv->xhv_fill++; /* HvFILL(hv)++ */
2521 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2526 ++entry->he_valu.hent_refcount;
2527 UNLOCK_STRTAB_MUTEX;
2529 if (flags & HVhek_FREEKEY)
2532 return HeKEY_hek(entry);
2536 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2539 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2540 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2541 if (uf->uf_set == NULL) {
2542 SV* obj = mg->mg_obj;
2543 mg->mg_obj = keysv; /* pass key */
2544 uf->uf_index = action; /* pass action */
2545 magic_getuvar((SV*)hv, mg);
2546 keysv = mg->mg_obj; /* may have changed */
2554 Perl_hv_placeholders_p(pTHX_ HV *hv)
2557 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2560 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2563 Perl_die(aTHX_ "panic: hv_placeholders_p");
2566 return &(mg->mg_len);
2571 Perl_hv_placeholders_get(pTHX_ HV *hv)
2574 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2576 return mg ? mg->mg_len : 0;
2580 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2583 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2588 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2589 Perl_die(aTHX_ "panic: hv_placeholders_set");
2591 /* else we don't need to add magic to record 0 placeholders. */
2595 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2599 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2604 value = &PL_sv_placeholder;
2607 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2610 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2613 case HVrhek_PV_UTF8:
2614 /* Create a string SV that directly points to the bytes in our
2616 value = newSV_type(SVt_PV);
2617 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2618 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2619 /* This stops anything trying to free it */
2620 SvLEN_set(value, 0);
2622 SvREADONLY_on(value);
2623 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2627 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2628 he->refcounted_he_data[0]);
2634 =for apidoc refcounted_he_chain_2hv
2636 Generates and returns a C<HV *> by walking up the tree starting at the passed
2637 in C<struct refcounted_he *>.
2642 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2646 U32 placeholders = 0;
2647 /* We could chase the chain once to get an idea of the number of keys,
2648 and call ksplit. But for now we'll make a potentially inefficient
2649 hash with only 8 entries in its array. */
2650 const U32 max = HvMAX(hv);
2654 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2655 HvARRAY(hv) = (HE**)array;
2660 U32 hash = chain->refcounted_he_hash;
2662 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2664 HE **oentry = &((HvARRAY(hv))[hash & max]);
2665 HE *entry = *oentry;
2668 for (; entry; entry = HeNEXT(entry)) {
2669 if (HeHASH(entry) == hash) {
2670 /* We might have a duplicate key here. If so, entry is older
2671 than the key we've already put in the hash, so if they are
2672 the same, skip adding entry. */
2674 const STRLEN klen = HeKLEN(entry);
2675 const char *const key = HeKEY(entry);
2676 if (klen == chain->refcounted_he_keylen
2677 && (!!HeKUTF8(entry)
2678 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2679 && memEQ(key, REF_HE_KEY(chain), klen))
2682 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2684 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2685 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2686 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2697 = share_hek_flags(REF_HE_KEY(chain),
2698 chain->refcounted_he_keylen,
2699 chain->refcounted_he_hash,
2700 (chain->refcounted_he_data[0]
2701 & (HVhek_UTF8|HVhek_WASUTF8)));
2703 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2705 value = refcounted_he_value(chain);
2706 if (value == &PL_sv_placeholder)
2708 HeVAL(entry) = value;
2710 /* Link it into the chain. */
2711 HeNEXT(entry) = *oentry;
2712 if (!HeNEXT(entry)) {
2713 /* initial entry. */
2721 chain = chain->refcounted_he_next;
2725 clear_placeholders(hv, placeholders);
2726 HvTOTALKEYS(hv) -= placeholders;
2729 /* We could check in the loop to see if we encounter any keys with key
2730 flags, but it's probably not worth it, as this per-hash flag is only
2731 really meant as an optimisation for things like Storable. */
2733 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2739 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2740 const char *key, STRLEN klen, int flags, U32 hash)
2743 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2744 of your key has to exactly match that which is stored. */
2745 SV *value = &PL_sv_placeholder;
2749 if (flags & HVhek_FREEKEY)
2751 key = SvPV_const(keysv, klen);
2753 is_utf8 = (SvUTF8(keysv) != 0);
2755 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2759 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2760 hash = SvSHARED_HASH(keysv);
2762 PERL_HASH(hash, key, klen);
2766 for (; chain; chain = chain->refcounted_he_next) {
2768 if (hash != chain->refcounted_he_hash)
2770 if (klen != chain->refcounted_he_keylen)
2772 if (memNE(REF_HE_KEY(chain),key,klen))
2774 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2777 if (hash != HEK_HASH(chain->refcounted_he_hek))
2779 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2781 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2783 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2787 value = sv_2mortal(refcounted_he_value(chain));
2791 if (flags & HVhek_FREEKEY)
2798 =for apidoc refcounted_he_new
2800 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2801 stored in a compact form, all references remain the property of the caller.
2802 The C<struct refcounted_he> is returned with a reference count of 1.
2807 struct refcounted_he *
2808 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2809 SV *const key, SV *const value) {
2811 struct refcounted_he *he;
2813 const char *key_p = SvPV_const(key, key_len);
2814 STRLEN value_len = 0;
2815 const char *value_p = NULL;
2820 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2823 value_type = HVrhek_PV;
2824 } else if (SvIOK(value)) {
2825 value_type = HVrhek_IV;
2826 } else if (value == &PL_sv_placeholder) {
2827 value_type = HVrhek_delete;
2828 } else if (!SvOK(value)) {
2829 value_type = HVrhek_undef;
2831 value_type = HVrhek_PV;
2834 if (value_type == HVrhek_PV) {
2835 value_p = SvPV_const(value, value_len);
2836 key_offset = value_len + 2;
2843 he = (struct refcounted_he*)
2844 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2848 he = (struct refcounted_he*)
2849 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2854 he->refcounted_he_next = parent;
2856 if (value_type == HVrhek_PV) {
2857 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2858 he->refcounted_he_val.refcounted_he_u_len = value_len;
2859 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2860 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2862 value_type = HVrhek_PV_UTF8;
2863 } else if (value_type == HVrhek_IV) {
2865 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2866 value_type = HVrhek_UV;
2868 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2874 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2875 As we're going to be building hash keys from this value in future,
2876 normalise it now. */
2877 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2878 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2880 PERL_HASH(hash, key_p, key_len);
2883 he->refcounted_he_hash = hash;
2884 he->refcounted_he_keylen = key_len;
2885 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2887 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2890 if (flags & HVhek_WASUTF8) {
2891 /* If it was downgraded from UTF-8, then the pointer returned from
2892 bytes_from_utf8 is an allocated pointer that we must free. */
2896 he->refcounted_he_data[0] = flags;
2897 he->refcounted_he_refcnt = 1;
2903 =for apidoc refcounted_he_free
2905 Decrements the reference count of the passed in C<struct refcounted_he *>
2906 by one. If the reference count reaches zero the structure's memory is freed,
2907 and C<refcounted_he_free> iterates onto the parent node.
2913 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2915 PERL_UNUSED_CONTEXT;
2918 struct refcounted_he *copy;
2922 new_count = --he->refcounted_he_refcnt;
2923 HINTS_REFCNT_UNLOCK;
2929 #ifndef USE_ITHREADS
2930 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2933 he = he->refcounted_he_next;
2934 PerlMemShared_free(copy);
2939 =for apidoc hv_assert
2941 Check that a hash is in an internally consistent state.
2949 Perl_hv_assert(pTHX_ HV *hv)
2954 int placeholders = 0;
2957 const I32 riter = HvRITER_get(hv);
2958 HE *eiter = HvEITER_get(hv);
2960 (void)hv_iterinit(hv);
2962 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2963 /* sanity check the values */
2964 if (HeVAL(entry) == &PL_sv_placeholder)
2968 /* sanity check the keys */
2969 if (HeSVKEY(entry)) {
2970 NOOP; /* Don't know what to check on SV keys. */
2971 } else if (HeKUTF8(entry)) {
2973 if (HeKWASUTF8(entry)) {
2974 PerlIO_printf(Perl_debug_log,
2975 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2976 (int) HeKLEN(entry), HeKEY(entry));
2979 } else if (HeKWASUTF8(entry))
2982 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2983 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2984 const int nhashkeys = HvUSEDKEYS(hv);
2985 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2987 if (nhashkeys != real) {
2988 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2991 if (nhashplaceholders != placeholders) {
2992 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2996 if (withflags && ! HvHASKFLAGS(hv)) {
2997 PerlIO_printf(Perl_debug_log,
2998 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3005 HvRITER_set(hv, riter); /* Restore hash iterator state */
3006 HvEITER_set(hv, eiter);
3013 * c-indentation-style: bsd
3015 * indent-tabs-mode: t
3018 * ex: set ts=8 sts=4 sw=4 noet: