3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
36 static const char S_strtab_error[]
37 = "Cannot modify shared string table in hv_%s";
46 he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
48 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
49 PL_body_roots[HE_SVSLOT] = he;
51 HeNEXT(he) = (HE*)(he + 1);
59 #define new_HE() (HE*)safemalloc(sizeof(HE))
60 #define del_HE(p) safefree((char*)p)
69 void ** const root = &PL_body_roots[HE_SVSLOT];
81 #define new_HE() new_he()
85 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
86 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 Newx(k, HEK_BASESIZE + len + 2, char);
103 Copy(str, HEK_KEY(hek), len, char);
104 HEK_KEY(hek)[len] = 0;
106 HEK_HASH(hek) = hash;
107 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
109 if (flags & HVhek_FREEKEY)
114 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
118 Perl_free_tied_hv_pool(pTHX)
121 HE *he = PL_hv_fetch_ent_mh;
124 Safefree(HeKEY_hek(he));
128 PL_hv_fetch_ent_mh = NULL;
131 #if defined(USE_ITHREADS)
133 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
135 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
137 PERL_UNUSED_ARG(param);
140 /* We already shared this hash key. */
141 (void)share_hek_hek(shared);
145 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
146 HEK_HASH(source), HEK_FLAGS(source));
147 ptr_table_store(PL_ptr_table, source, shared);
153 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
159 /* look for it in the table first */
160 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
164 /* create anew and remember what it is */
166 ptr_table_store(PL_ptr_table, e, ret);
168 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
169 if (HeKLEN(e) == HEf_SVKEY) {
171 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
172 HeKEY_hek(ret) = (HEK*)k;
173 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
176 /* This is hek_dup inlined, which seems to be important for speed
178 HEK * const source = HeKEY_hek(e);
179 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
182 /* We already shared this hash key. */
183 (void)share_hek_hek(shared);
187 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
188 HEK_HASH(source), HEK_FLAGS(source));
189 ptr_table_store(PL_ptr_table, source, shared);
191 HeKEY_hek(ret) = shared;
194 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
196 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
199 #endif /* USE_ITHREADS */
202 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
205 SV * const sv = sv_newmortal();
206 if (!(flags & HVhek_FREEKEY)) {
207 sv_setpvn(sv, key, klen);
210 /* Need to free saved eventually assign to mortal SV */
211 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
212 sv_usepvn(sv, (char *) key, klen);
214 if (flags & HVhek_UTF8) {
217 Perl_croak(aTHX_ msg, SVfARG(sv));
220 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
223 #define HV_FETCH_ISSTORE 0x01
224 #define HV_FETCH_ISEXISTS 0x02
225 #define HV_FETCH_LVALUE 0x04
226 #define HV_FETCH_JUST_SV 0x08
231 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
232 the length of the key. The C<hash> parameter is the precomputed hash
233 value; if it is zero then Perl will compute it. The return value will be
234 NULL if the operation failed or if the value did not need to be actually
235 stored within the hash (as in the case of tied hashes). Otherwise it can
236 be dereferenced to get the original C<SV*>. Note that the caller is
237 responsible for suitably incrementing the reference count of C<val> before
238 the call, and decrementing it if the function returned NULL. Effectively
239 a successful hv_store takes ownership of one reference to C<val>. This is
240 usually what you want; a newly created SV has a reference count of one, so
241 if all your code does is create SVs then store them in a hash, hv_store
242 will own the only reference to the new SV, and your code doesn't need to do
243 anything further to tidy up. hv_store is not implemented as a call to
244 hv_store_ent, and does not create a temporary SV for the key, so if your
245 key data is not already in SV form then use hv_store in preference to
248 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
249 information on how to use this function on tied hashes.
255 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
268 hek = hv_fetch_common (hv, NULL, key, klen, flags,
269 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
270 return hek ? &HeVAL(hek) : NULL;
273 /* XXX This looks like an ideal candidate to inline */
275 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
276 register U32 hash, int flags)
278 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
279 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
280 return hek ? &HeVAL(hek) : NULL;
284 =for apidoc hv_store_ent
286 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
287 parameter is the precomputed hash value; if it is zero then Perl will
288 compute it. The return value is the new hash entry so created. It will be
289 NULL if the operation failed or if the value did not need to be actually
290 stored within the hash (as in the case of tied hashes). Otherwise the
291 contents of the return value can be accessed using the C<He?> macros
292 described here. Note that the caller is responsible for suitably
293 incrementing the reference count of C<val> before the call, and
294 decrementing it if the function returned NULL. Effectively a successful
295 hv_store_ent takes ownership of one reference to C<val>. This is
296 usually what you want; a newly created SV has a reference count of one, so
297 if all your code does is create SVs then store them in a hash, hv_store
298 will own the only reference to the new SV, and your code doesn't need to do
299 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
300 unlike C<val> it does not take ownership of it, so maintaining the correct
301 reference count on C<key> is entirely the caller's responsibility. hv_store
302 is not implemented as a call to hv_store_ent, and does not create a temporary
303 SV for the key, so if your key data is not already in SV form then use
304 hv_store in preference to hv_store_ent.
306 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
307 information on how to use this function on tied hashes.
312 /* XXX This looks like an ideal candidate to inline */
314 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
316 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
320 =for apidoc hv_exists
322 Returns a boolean indicating whether the specified hash key exists. The
323 C<klen> is the length of the key.
329 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
341 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
348 Returns the SV which corresponds to the specified key in the hash. The
349 C<klen> is the length of the key. If C<lval> is set then the fetch will be
350 part of a store. Check that the return value is non-null before
351 dereferencing it to an C<SV*>.
353 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
354 information on how to use this function on tied hashes.
360 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
373 hek = hv_fetch_common (hv, NULL, key, klen, flags,
374 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
376 return hek ? &HeVAL(hek) : NULL;
380 =for apidoc hv_exists_ent
382 Returns a boolean indicating whether the specified hash key exists. C<hash>
383 can be a valid precomputed hash value, or 0 to ask for it to be
389 /* XXX This looks like an ideal candidate to inline */
391 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
393 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
397 /* returns an HE * structure with the all fields set */
398 /* note that hent_val will be a mortal sv for MAGICAL hashes */
400 =for apidoc hv_fetch_ent
402 Returns the hash entry which corresponds to the specified key in the hash.
403 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
404 if you want the function to compute it. IF C<lval> is set then the fetch
405 will be part of a store. Make sure the return value is non-null before
406 accessing it. The return value when C<tb> is a tied hash is a pointer to a
407 static location, so be sure to make a copy of the structure if you need to
410 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
411 information on how to use this function on tied hashes.
417 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
419 return hv_fetch_common(hv, keysv, NULL, 0, 0,
420 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
424 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
425 int flags, int action, SV *val, register U32 hash)
439 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
440 keysv = hv_magic_uvar_xkey(hv, keysv, action);
441 if (flags & HVhek_FREEKEY)
443 key = SvPV_const(keysv, klen);
445 is_utf8 = (SvUTF8(keysv) != 0);
447 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
450 xhv = (XPVHV*)SvANY(hv);
452 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
453 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
455 /* XXX should be able to skimp on the HE/HEK here when
456 HV_FETCH_JUST_SV is true. */
458 keysv = newSVpvn(key, klen);
463 keysv = newSVsv(keysv);
466 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
468 /* grab a fake HE/HEK pair from the pool or make a new one */
469 entry = PL_hv_fetch_ent_mh;
471 PL_hv_fetch_ent_mh = HeNEXT(entry);
475 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
476 HeKEY_hek(entry) = (HEK*)k;
478 HeNEXT(entry) = NULL;
479 HeSVKEY_set(entry, keysv);
481 sv_upgrade(sv, SVt_PVLV);
483 /* so we can free entry when freeing sv */
484 LvTARG(sv) = (SV*)entry;
486 /* XXX remove at some point? */
487 if (flags & HVhek_FREEKEY)
492 #ifdef ENV_IS_CASELESS
493 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
495 for (i = 0; i < klen; ++i)
496 if (isLOWER(key[i])) {
497 /* Would be nice if we had a routine to do the
498 copy and upercase in a single pass through. */
499 const char * const nkey = strupr(savepvn(key,klen));
500 /* Note that this fetch is for nkey (the uppercased
501 key) whereas the store is for key (the original) */
502 entry = hv_fetch_common(hv, NULL, nkey, klen,
503 HVhek_FREEKEY, /* free nkey */
504 0 /* non-LVAL fetch */,
506 0 /* compute hash */);
507 if (!entry && (action & HV_FETCH_LVALUE)) {
508 /* This call will free key if necessary.
509 Do it this way to encourage compiler to tail
511 entry = hv_fetch_common(hv, keysv, key, klen,
512 flags, HV_FETCH_ISSTORE,
515 if (flags & HVhek_FREEKEY)
523 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
524 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
525 /* I don't understand why hv_exists_ent has svret and sv,
526 whereas hv_exists only had one. */
527 SV * const svret = sv_newmortal();
530 if (keysv || is_utf8) {
532 keysv = newSVpvn(key, klen);
535 keysv = newSVsv(keysv);
537 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
539 mg_copy((SV*)hv, sv, key, klen);
541 if (flags & HVhek_FREEKEY)
543 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
544 /* This cast somewhat evil, but I'm merely using NULL/
545 not NULL to return the boolean exists.
546 And I know hv is not NULL. */
547 return SvTRUE(svret) ? (HE *)hv : NULL;
549 #ifdef ENV_IS_CASELESS
550 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
551 /* XXX This code isn't UTF8 clean. */
552 char * const keysave = (char * const)key;
553 /* Will need to free this, so set FREEKEY flag. */
554 key = savepvn(key,klen);
555 key = (const char*)strupr((char*)key);
560 if (flags & HVhek_FREEKEY) {
563 flags |= HVhek_FREEKEY;
567 else if (action & HV_FETCH_ISSTORE) {
570 hv_magic_check (hv, &needs_copy, &needs_store);
572 const bool save_taint = PL_tainted;
573 if (keysv || is_utf8) {
575 keysv = newSVpvn(key, klen);
579 PL_tainted = SvTAINTED(keysv);
580 keysv = sv_2mortal(newSVsv(keysv));
581 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
583 mg_copy((SV*)hv, val, key, klen);
586 TAINT_IF(save_taint);
588 if (flags & HVhek_FREEKEY)
592 #ifdef ENV_IS_CASELESS
593 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
594 /* XXX This code isn't UTF8 clean. */
595 const char *keysave = key;
596 /* Will need to free this, so set FREEKEY flag. */
597 key = savepvn(key,klen);
598 key = (const char*)strupr((char*)key);
603 if (flags & HVhek_FREEKEY) {
606 flags |= HVhek_FREEKEY;
614 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
615 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
616 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
621 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
623 HvARRAY(hv) = (HE**)array;
625 #ifdef DYNAMIC_ENV_FETCH
626 else if (action & HV_FETCH_ISEXISTS) {
627 /* for an %ENV exists, if we do an insert it's by a recursive
628 store call, so avoid creating HvARRAY(hv) right now. */
632 /* XXX remove at some point? */
633 if (flags & HVhek_FREEKEY)
641 char * const keysave = (char *)key;
642 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
646 flags &= ~HVhek_UTF8;
647 if (key != keysave) {
648 if (flags & HVhek_FREEKEY)
650 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
655 PERL_HASH_INTERNAL(hash, key, klen);
656 /* We don't have a pointer to the hv, so we have to replicate the
657 flag into every HEK, so that hv_iterkeysv can see it. */
658 /* And yes, you do need this even though you are not "storing" because
659 you can flip the flags below if doing an lval lookup. (And that
660 was put in to give the semantics Andreas was expecting.) */
661 flags |= HVhek_REHASH;
663 if (keysv && (SvIsCOW_shared_hash(keysv))) {
664 hash = SvSHARED_HASH(keysv);
666 PERL_HASH(hash, key, klen);
670 masked_flags = (flags & HVhek_MASK);
672 #ifdef DYNAMIC_ENV_FETCH
673 if (!HvARRAY(hv)) entry = NULL;
677 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
679 for (; entry; entry = HeNEXT(entry)) {
680 if (HeHASH(entry) != hash) /* strings can't be equal */
682 if (HeKLEN(entry) != (I32)klen)
684 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
686 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
689 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
690 if (HeKFLAGS(entry) != masked_flags) {
691 /* We match if HVhek_UTF8 bit in our flags and hash key's
692 match. But if entry was set previously with HVhek_WASUTF8
693 and key now doesn't (or vice versa) then we should change
694 the key's flag, as this is assignment. */
695 if (HvSHAREKEYS(hv)) {
696 /* Need to swap the key we have for a key with the flags we
697 need. As keys are shared we can't just write to the
698 flag, so we share the new one, unshare the old one. */
699 HEK * const new_hek = share_hek_flags(key, klen, hash,
701 unshare_hek (HeKEY_hek(entry));
702 HeKEY_hek(entry) = new_hek;
704 else if (hv == PL_strtab) {
705 /* PL_strtab is usually the only hash without HvSHAREKEYS,
706 so putting this test here is cheap */
707 if (flags & HVhek_FREEKEY)
709 Perl_croak(aTHX_ S_strtab_error,
710 action & HV_FETCH_LVALUE ? "fetch" : "store");
713 HeKFLAGS(entry) = masked_flags;
714 if (masked_flags & HVhek_ENABLEHVKFLAGS)
717 if (HeVAL(entry) == &PL_sv_placeholder) {
718 /* yes, can store into placeholder slot */
719 if (action & HV_FETCH_LVALUE) {
721 /* This preserves behaviour with the old hv_fetch
722 implementation which at this point would bail out
723 with a break; (at "if we find a placeholder, we
724 pretend we haven't found anything")
726 That break mean that if a placeholder were found, it
727 caused a call into hv_store, which in turn would
728 check magic, and if there is no magic end up pretty
729 much back at this point (in hv_store's code). */
732 /* LVAL fetch which actaully needs a store. */
734 HvPLACEHOLDERS(hv)--;
737 if (val != &PL_sv_placeholder)
738 HvPLACEHOLDERS(hv)--;
741 } else if (action & HV_FETCH_ISSTORE) {
742 SvREFCNT_dec(HeVAL(entry));
745 } else if (HeVAL(entry) == &PL_sv_placeholder) {
746 /* if we find a placeholder, we pretend we haven't found
750 if (flags & HVhek_FREEKEY)
754 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
755 if (!(action & HV_FETCH_ISSTORE)
756 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
758 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
760 sv = newSVpvn(env,len);
762 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,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, val, hash);
788 /* XXX Surely that could leak if the fetch-was-store fails?
789 Just like the hv_fetch. */
793 /* Welcome to hv_store... */
796 /* Not sure if we can get here. I think the only case of oentry being
797 NULL is for %ENV with dynamic env fetch. But that should disappear
798 with magic in the previous code. */
801 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
803 HvARRAY(hv) = (HE**)array;
806 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
809 /* share_hek_flags will do the free for us. This might be considered
812 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
813 else if (hv == PL_strtab) {
814 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
815 this test here is cheap */
816 if (flags & HVhek_FREEKEY)
818 Perl_croak(aTHX_ S_strtab_error,
819 action & HV_FETCH_LVALUE ? "fetch" : "store");
821 else /* gotta do the real thing */
822 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
824 HeNEXT(entry) = *oentry;
827 if (val == &PL_sv_placeholder)
828 HvPLACEHOLDERS(hv)++;
829 if (masked_flags & HVhek_ENABLEHVKFLAGS)
833 const HE *counter = HeNEXT(entry);
835 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
836 if (!counter) { /* initial entry? */
837 xhv->xhv_fill++; /* HvFILL(hv)++ */
838 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
840 } else if(!HvREHASH(hv)) {
843 while ((counter = HeNEXT(counter)))
846 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
847 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
848 bucket splits on a rehashed hash, as we're not going to
849 split it again, and if someone is lucky (evil) enough to
850 get all the keys in one list they could exhaust our memory
851 as we repeatedly double the number of buckets on every
852 entry. Linear search feels a less worse thing to do. */
862 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
864 const MAGIC *mg = SvMAGIC(hv);
868 if (isUPPER(mg->mg_type)) {
870 if (mg->mg_type == PERL_MAGIC_tied) {
871 *needs_store = FALSE;
872 return; /* We've set all there is to set. */
875 mg = mg->mg_moremagic;
880 =for apidoc hv_scalar
882 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
888 Perl_hv_scalar(pTHX_ HV *hv)
892 if (SvRMAGICAL(hv)) {
893 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
895 return magic_scalarpack(hv, mg);
900 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
901 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
909 =for apidoc hv_delete
911 Deletes a key/value pair in the hash. The value SV is removed from the
912 hash and returned to the caller. The C<klen> is the length of the key.
913 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
920 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
927 k_flags = HVhek_UTF8;
932 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
936 =for apidoc hv_delete_ent
938 Deletes a key/value pair in the hash. The value SV is removed from the
939 hash and returned to the caller. The C<flags> value will normally be zero;
940 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
941 precomputed hash value, or 0 to ask for it to be computed.
946 /* XXX This looks like an ideal candidate to inline */
948 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
950 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
954 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
955 int k_flags, I32 d_flags, U32 hash)
960 register HE **oentry;
961 HE *const *first_entry;
969 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
970 keysv = hv_magic_uvar_xkey(hv, keysv, -1);
971 if (k_flags & HVhek_FREEKEY)
973 key = SvPV_const(keysv, klen);
975 is_utf8 = (SvUTF8(keysv) != 0);
977 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
980 if (SvRMAGICAL(hv)) {
983 hv_magic_check (hv, &needs_copy, &needs_store);
987 entry = hv_fetch_common(hv, keysv, key, klen,
988 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
990 sv = entry ? HeVAL(entry) : NULL;
996 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
997 /* No longer an element */
998 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1001 return NULL; /* element cannot be deleted */
1003 #ifdef ENV_IS_CASELESS
1004 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1005 /* XXX This code isn't UTF8 clean. */
1006 keysv = sv_2mortal(newSVpvn(key,klen));
1007 if (k_flags & HVhek_FREEKEY) {
1010 key = strupr(SvPVX(keysv));
1019 xhv = (XPVHV*)SvANY(hv);
1024 const char * const keysave = key;
1025 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1028 k_flags |= HVhek_UTF8;
1030 k_flags &= ~HVhek_UTF8;
1031 if (key != keysave) {
1032 if (k_flags & HVhek_FREEKEY) {
1033 /* This shouldn't happen if our caller does what we expect,
1034 but strictly the API allows it. */
1037 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1039 HvHASKFLAGS_on((SV*)hv);
1043 PERL_HASH_INTERNAL(hash, key, klen);
1045 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1046 hash = SvSHARED_HASH(keysv);
1048 PERL_HASH(hash, key, klen);
1052 masked_flags = (k_flags & HVhek_MASK);
1054 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1056 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1058 if (HeHASH(entry) != hash) /* strings can't be equal */
1060 if (HeKLEN(entry) != (I32)klen)
1062 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1064 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1067 if (hv == PL_strtab) {
1068 if (k_flags & HVhek_FREEKEY)
1070 Perl_croak(aTHX_ S_strtab_error, "delete");
1073 /* if placeholder is here, it's already been deleted.... */
1074 if (HeVAL(entry) == &PL_sv_placeholder) {
1075 if (k_flags & HVhek_FREEKEY)
1079 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1080 hv_notallowed(k_flags, key, klen,
1081 "Attempt to delete readonly key '%"SVf"' from"
1082 " a restricted hash");
1084 if (k_flags & HVhek_FREEKEY)
1087 if (d_flags & G_DISCARD)
1090 sv = sv_2mortal(HeVAL(entry));
1091 HeVAL(entry) = &PL_sv_placeholder;
1095 * If a restricted hash, rather than really deleting the entry, put
1096 * a placeholder there. This marks the key as being "approved", so
1097 * we can still access via not-really-existing key without raising
1100 if (SvREADONLY(hv)) {
1101 SvREFCNT_dec(HeVAL(entry));
1102 HeVAL(entry) = &PL_sv_placeholder;
1103 /* We'll be saving this slot, so the number of allocated keys
1104 * doesn't go down, but the number placeholders goes up */
1105 HvPLACEHOLDERS(hv)++;
1107 *oentry = HeNEXT(entry);
1109 xhv->xhv_fill--; /* HvFILL(hv)-- */
1111 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1114 hv_free_ent(hv, entry);
1115 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1116 if (xhv->xhv_keys == 0)
1117 HvHASKFLAGS_off(hv);
1121 if (SvREADONLY(hv)) {
1122 hv_notallowed(k_flags, key, klen,
1123 "Attempt to delete disallowed key '%"SVf"' from"
1124 " a restricted hash");
1127 if (k_flags & HVhek_FREEKEY)
1133 S_hsplit(pTHX_ HV *hv)
1136 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1137 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1138 register I32 newsize = oldsize * 2;
1140 char *a = (char*) HvARRAY(hv);
1142 register HE **oentry;
1143 int longest_chain = 0;
1146 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1147 (void*)hv, (int) oldsize);*/
1149 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1150 /* Can make this clear any placeholders first for non-restricted hashes,
1151 even though Storable rebuilds restricted hashes by putting in all the
1152 placeholders (first) before turning on the readonly flag, because
1153 Storable always pre-splits the hash. */
1154 hv_clear_placeholders(hv);
1158 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1159 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1160 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1166 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1169 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1170 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1175 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1177 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1179 if (oldsize >= 64) {
1180 offer_nice_chunk(HvARRAY(hv),
1181 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1182 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1185 Safefree(HvARRAY(hv));
1189 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1190 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1191 HvARRAY(hv) = (HE**) a;
1194 for (i=0; i<oldsize; i++,aep++) {
1195 int left_length = 0;
1196 int right_length = 0;
1200 if (!*aep) /* non-existent */
1203 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1204 if ((HeHASH(entry) & newsize) != (U32)i) {
1205 *oentry = HeNEXT(entry);
1206 HeNEXT(entry) = *bep;
1208 xhv->xhv_fill++; /* HvFILL(hv)++ */
1214 oentry = &HeNEXT(entry);
1218 if (!*aep) /* everything moved */
1219 xhv->xhv_fill--; /* HvFILL(hv)-- */
1220 /* I think we don't actually need to keep track of the longest length,
1221 merely flag if anything is too long. But for the moment while
1222 developing this code I'll track it. */
1223 if (left_length > longest_chain)
1224 longest_chain = left_length;
1225 if (right_length > longest_chain)
1226 longest_chain = right_length;
1230 /* Pick your policy for "hashing isn't working" here: */
1231 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1236 if (hv == PL_strtab) {
1237 /* Urg. Someone is doing something nasty to the string table.
1242 /* Awooga. Awooga. Pathological data. */
1243 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1244 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1247 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1248 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1250 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1253 was_shared = HvSHAREKEYS(hv);
1256 HvSHAREKEYS_off(hv);
1261 for (i=0; i<newsize; i++,aep++) {
1262 register HE *entry = *aep;
1264 /* We're going to trash this HE's next pointer when we chain it
1265 into the new hash below, so store where we go next. */
1266 HE * const next = HeNEXT(entry);
1271 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1276 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1277 hash, HeKFLAGS(entry));
1278 unshare_hek (HeKEY_hek(entry));
1279 HeKEY_hek(entry) = new_hek;
1281 /* Not shared, so simply write the new hash in. */
1282 HeHASH(entry) = hash;
1284 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1285 HEK_REHASH_on(HeKEY_hek(entry));
1286 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1288 /* Copy oentry to the correct new chain. */
1289 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1291 xhv->xhv_fill++; /* HvFILL(hv)++ */
1292 HeNEXT(entry) = *bep;
1298 Safefree (HvARRAY(hv));
1299 HvARRAY(hv) = (HE **)a;
1303 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1306 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1307 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1308 register I32 newsize;
1313 register HE **oentry;
1315 newsize = (I32) newmax; /* possible truncation here */
1316 if (newsize != newmax || newmax <= oldsize)
1318 while ((newsize & (1 + ~newsize)) != newsize) {
1319 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1321 if (newsize < newmax)
1323 if (newsize < newmax)
1324 return; /* overflow detection */
1326 a = (char *) HvARRAY(hv);
1329 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1330 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1331 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1337 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1340 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1341 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1346 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1348 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1350 if (oldsize >= 64) {
1351 offer_nice_chunk(HvARRAY(hv),
1352 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1353 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1356 Safefree(HvARRAY(hv));
1359 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1362 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1364 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1365 HvARRAY(hv) = (HE **) a;
1366 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1370 for (i=0; i<oldsize; i++,aep++) {
1371 if (!*aep) /* non-existent */
1373 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1374 register I32 j = (HeHASH(entry) & newsize);
1378 *oentry = HeNEXT(entry);
1379 if (!(HeNEXT(entry) = aep[j]))
1380 xhv->xhv_fill++; /* HvFILL(hv)++ */
1385 oentry = &HeNEXT(entry);
1387 if (!*aep) /* everything moved */
1388 xhv->xhv_fill--; /* HvFILL(hv)-- */
1395 Creates a new HV. The reference count is set to 1.
1403 register XPVHV* xhv;
1404 HV * const hv = (HV*)newSV(0);
1406 sv_upgrade((SV *)hv, SVt_PVHV);
1407 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 PL_sub_generation++; /* may be 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);
1623 HvEITER_set(hv, NULL);
1628 =for apidoc hv_clear_placeholders
1630 Clears any placeholders from a hash. If a restricted hash has any of its keys
1631 marked as readonly and the key is subsequently deleted, the key is not actually
1632 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1633 it so it will be ignored by future operations such as iterating over the hash,
1634 but will still allow the hash to have a value reassigned to the key at some
1635 future point. This function clears any such placeholder keys from the hash.
1636 See Hash::Util::lock_keys() for an example of its use.
1642 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1645 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1648 clear_placeholders(hv, items);
1652 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1662 /* Loop down the linked list heads */
1664 HE **oentry = &(HvARRAY(hv))[i];
1667 while ((entry = *oentry)) {
1668 if (HeVAL(entry) == &PL_sv_placeholder) {
1669 *oentry = HeNEXT(entry);
1670 if (first && !*oentry)
1671 HvFILL(hv)--; /* This linked list is now empty. */
1672 if (entry == HvEITER_get(hv))
1675 hv_free_ent(hv, entry);
1679 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1680 if (HvKEYS(hv) == 0)
1681 HvHASKFLAGS_off(hv);
1682 HvPLACEHOLDERS_set(hv, 0);
1686 oentry = &HeNEXT(entry);
1691 /* You can't get here, hence assertion should always fail. */
1692 assert (items == 0);
1697 S_hfreeentries(pTHX_ HV *hv)
1699 /* This is the array that we're going to restore */
1700 HE **const orig_array = HvARRAY(hv);
1708 /* If the hash is actually a symbol table with a name, look after the
1710 struct xpvhv_aux *iter = HvAUX(hv);
1712 name = iter->xhv_name;
1713 iter->xhv_name = NULL;
1718 /* orig_array remains unchanged throughout the loop. If after freeing all
1719 the entries it turns out that one of the little blighters has triggered
1720 an action that has caused HvARRAY to be re-allocated, then we set
1721 array to the new HvARRAY, and try again. */
1724 /* This is the one we're going to try to empty. First time round
1725 it's the original array. (Hopefully there will only be 1 time
1727 HE ** const array = HvARRAY(hv);
1730 /* Because we have taken xhv_name out, the only allocated pointer
1731 in the aux structure that might exist is the backreference array.
1736 struct xpvhv_aux *iter = HvAUX(hv);
1737 /* If there are weak references to this HV, we need to avoid
1738 freeing them up here. In particular we need to keep the AV
1739 visible as what we're deleting might well have weak references
1740 back to this HV, so the for loop below may well trigger
1741 the removal of backreferences from this array. */
1743 if (iter->xhv_backreferences) {
1744 /* So donate them to regular backref magic to keep them safe.
1745 The sv_magic will increase the reference count of the AV,
1746 so we need to drop it first. */
1747 SvREFCNT_dec(iter->xhv_backreferences);
1748 if (AvFILLp(iter->xhv_backreferences) == -1) {
1749 /* Turns out that the array is empty. Just free it. */
1750 SvREFCNT_dec(iter->xhv_backreferences);
1753 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1754 PERL_MAGIC_backref, NULL, 0);
1756 iter->xhv_backreferences = NULL;
1759 entry = iter->xhv_eiter; /* HvEITER(hv) */
1760 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1762 hv_free_ent(hv, entry);
1764 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1765 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1767 /* There are now no allocated pointers in the aux structure. */
1769 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1770 /* What aux structure? */
1773 /* make everyone else think the array is empty, so that the destructors
1774 * called for freed entries can't recusively mess with us */
1777 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1781 /* Loop down the linked list heads */
1782 HE *entry = array[i];
1785 register HE * const oentry = entry;
1786 entry = HeNEXT(entry);
1787 hv_free_ent(hv, oentry);
1791 /* As there are no allocated pointers in the aux structure, it's now
1792 safe to free the array we just cleaned up, if it's not the one we're
1793 going to put back. */
1794 if (array != orig_array) {
1799 /* Good. No-one added anything this time round. */
1804 /* Someone attempted to iterate or set the hash name while we had
1805 the array set to 0. We'll catch backferences on the next time
1806 round the while loop. */
1807 assert(HvARRAY(hv));
1809 if (HvAUX(hv)->xhv_name) {
1810 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1814 if (--attempts == 0) {
1815 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1819 HvARRAY(hv) = orig_array;
1821 /* If the hash was actually a symbol table, put the name back. */
1823 /* We have restored the original array. If name is non-NULL, then
1824 the original array had an aux structure at the end. So this is
1826 SvFLAGS(hv) |= SVf_OOK;
1827 HvAUX(hv)->xhv_name = name;
1832 =for apidoc hv_undef
1840 Perl_hv_undef(pTHX_ HV *hv)
1843 register XPVHV* xhv;
1848 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1849 xhv = (XPVHV*)SvANY(hv);
1851 if ((name = HvNAME_get(hv))) {
1853 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1854 hv_name_set(hv, NULL, 0, 0);
1856 SvFLAGS(hv) &= ~SVf_OOK;
1857 Safefree(HvARRAY(hv));
1858 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1860 HvPLACEHOLDERS_set(hv, 0);
1866 static struct xpvhv_aux*
1867 S_hv_auxinit(HV *hv) {
1868 struct xpvhv_aux *iter;
1872 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1873 + sizeof(struct xpvhv_aux), char);
1875 array = (char *) HvARRAY(hv);
1876 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1877 + sizeof(struct xpvhv_aux), char);
1879 HvARRAY(hv) = (HE**) array;
1880 /* SvOOK_on(hv) attacks the IV flags. */
1881 SvFLAGS(hv) |= SVf_OOK;
1884 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1885 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1887 iter->xhv_backreferences = 0;
1892 =for apidoc hv_iterinit
1894 Prepares a starting point to traverse a hash table. Returns the number of
1895 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1896 currently only meaningful for hashes without tie magic.
1898 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1899 hash buckets that happen to be in use. If you still need that esoteric
1900 value, you can get it through the macro C<HvFILL(tb)>.
1907 Perl_hv_iterinit(pTHX_ HV *hv)
1910 Perl_croak(aTHX_ "Bad hash");
1913 struct xpvhv_aux * const iter = HvAUX(hv);
1914 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1915 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1917 hv_free_ent(hv, entry);
1919 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1920 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1925 /* used to be xhv->xhv_fill before 5.004_65 */
1926 return HvTOTALKEYS(hv);
1930 Perl_hv_riter_p(pTHX_ HV *hv) {
1931 struct xpvhv_aux *iter;
1934 Perl_croak(aTHX_ "Bad hash");
1936 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1937 return &(iter->xhv_riter);
1941 Perl_hv_eiter_p(pTHX_ HV *hv) {
1942 struct xpvhv_aux *iter;
1945 Perl_croak(aTHX_ "Bad hash");
1947 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1948 return &(iter->xhv_eiter);
1952 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1953 struct xpvhv_aux *iter;
1956 Perl_croak(aTHX_ "Bad hash");
1964 iter = hv_auxinit(hv);
1966 iter->xhv_riter = riter;
1970 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1971 struct xpvhv_aux *iter;
1974 Perl_croak(aTHX_ "Bad hash");
1979 /* 0 is the default so don't go malloc()ing a new structure just to
1984 iter = hv_auxinit(hv);
1986 iter->xhv_eiter = eiter;
1990 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1993 struct xpvhv_aux *iter;
1996 PERL_UNUSED_ARG(flags);
1999 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2003 if (iter->xhv_name) {
2004 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2010 iter = hv_auxinit(hv);
2012 PERL_HASH(hash, name, len);
2013 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2017 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2018 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2019 PERL_UNUSED_CONTEXT;
2020 return &(iter->xhv_backreferences);
2024 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2030 av = HvAUX(hv)->xhv_backreferences;
2033 HvAUX(hv)->xhv_backreferences = 0;
2034 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2039 hv_iternext is implemented as a macro in hv.h
2041 =for apidoc hv_iternext
2043 Returns entries from a hash iterator. See C<hv_iterinit>.
2045 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2046 iterator currently points to, without losing your place or invalidating your
2047 iterator. Note that in this case the current entry is deleted from the hash
2048 with your iterator holding the last reference to it. Your iterator is flagged
2049 to free the entry on the next call to C<hv_iternext>, so you must not discard
2050 your iterator immediately else the entry will leak - call C<hv_iternext> to
2051 trigger the resource deallocation.
2053 =for apidoc hv_iternext_flags
2055 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2056 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2057 set the placeholders keys (for restricted hashes) will be returned in addition
2058 to normal keys. By default placeholders are automatically skipped over.
2059 Currently a placeholder is implemented with a value that is
2060 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2061 restricted hashes may change, and the implementation currently is
2062 insufficiently abstracted for any change to be tidy.
2068 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2071 register XPVHV* xhv;
2075 struct xpvhv_aux *iter;
2078 Perl_croak(aTHX_ "Bad hash");
2080 xhv = (XPVHV*)SvANY(hv);
2083 /* Too many things (well, pp_each at least) merrily assume that you can
2084 call iv_iternext without calling hv_iterinit, so we'll have to deal
2090 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2091 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2092 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2093 SV * const key = sv_newmortal();
2095 sv_setsv(key, HeSVKEY_force(entry));
2096 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2102 /* one HE per MAGICAL hash */
2103 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2105 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2107 HeKEY_hek(entry) = hek;
2108 HeKLEN(entry) = HEf_SVKEY;
2110 magic_nextpack((SV*) hv,mg,key);
2112 /* force key to stay around until next time */
2113 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2114 return entry; /* beware, hent_val is not set */
2117 SvREFCNT_dec(HeVAL(entry));
2118 Safefree(HeKEY_hek(entry));
2120 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2124 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2125 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2128 /* The prime_env_iter() on VMS just loaded up new hash values
2129 * so the iteration count needs to be reset back to the beginning
2133 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2138 /* hv_iterint now ensures this. */
2139 assert (HvARRAY(hv));
2141 /* At start of hash, entry is NULL. */
2144 entry = HeNEXT(entry);
2145 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2147 * Skip past any placeholders -- don't want to include them in
2150 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2151 entry = HeNEXT(entry);
2156 /* OK. Come to the end of the current list. Grab the next one. */
2158 iter->xhv_riter++; /* HvRITER(hv)++ */
2159 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2160 /* There is no next one. End of the hash. */
2161 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2164 entry = (HvARRAY(hv))[iter->xhv_riter];
2166 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2167 /* If we have an entry, but it's a placeholder, don't count it.
2169 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2170 entry = HeNEXT(entry);
2172 /* Will loop again if this linked list starts NULL
2173 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2174 or if we run through it and find only placeholders. */
2177 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2179 hv_free_ent(hv, oldentry);
2182 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2183 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2185 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2190 =for apidoc hv_iterkey
2192 Returns the key from the current position of the hash iterator. See
2199 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2201 if (HeKLEN(entry) == HEf_SVKEY) {
2203 char * const p = SvPV(HeKEY_sv(entry), len);
2208 *retlen = HeKLEN(entry);
2209 return HeKEY(entry);
2213 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2215 =for apidoc hv_iterkeysv
2217 Returns the key as an C<SV*> from the current position of the hash
2218 iterator. The return value will always be a mortal copy of the key. Also
2225 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2227 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2231 =for apidoc hv_iterval
2233 Returns the value from the current position of the hash iterator. See
2240 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2242 if (SvRMAGICAL(hv)) {
2243 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2244 SV* const sv = sv_newmortal();
2245 if (HeKLEN(entry) == HEf_SVKEY)
2246 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2248 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2252 return HeVAL(entry);
2256 =for apidoc hv_iternextsv
2258 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2265 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2267 HE * const he = hv_iternext_flags(hv, 0);
2271 *key = hv_iterkey(he, retlen);
2272 return hv_iterval(hv, he);
2279 =for apidoc hv_magic
2281 Adds magic to a hash. See C<sv_magic>.
2286 /* possibly free a shared string if no one has access to it
2287 * len and hash must both be valid for str.
2290 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2292 unshare_hek_or_pvn (NULL, str, len, hash);
2297 Perl_unshare_hek(pTHX_ HEK *hek)
2299 unshare_hek_or_pvn(hek, NULL, 0, 0);
2302 /* possibly free a shared string if no one has access to it
2303 hek if non-NULL takes priority over the other 3, else str, len and hash
2304 are used. If so, len and hash must both be valid for str.
2307 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2310 register XPVHV* xhv;
2312 register HE **oentry;
2314 bool is_utf8 = FALSE;
2316 const char * const save = str;
2317 struct shared_he *he = NULL;
2320 /* Find the shared he which is just before us in memory. */
2321 he = (struct shared_he *)(((char *)hek)
2322 - STRUCT_OFFSET(struct shared_he,
2325 /* Assert that the caller passed us a genuine (or at least consistent)
2327 assert (he->shared_he_he.hent_hek == hek);
2330 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2331 --he->shared_he_he.he_valu.hent_refcount;
2332 UNLOCK_STRTAB_MUTEX;
2335 UNLOCK_STRTAB_MUTEX;
2337 hash = HEK_HASH(hek);
2338 } else if (len < 0) {
2339 STRLEN tmplen = -len;
2341 /* See the note in hv_fetch(). --jhi */
2342 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2345 k_flags = HVhek_UTF8;
2347 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2350 /* what follows was the moral equivalent of:
2351 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2353 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2355 xhv = (XPVHV*)SvANY(PL_strtab);
2356 /* assert(xhv_array != 0) */
2358 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2360 const HE *const he_he = &(he->shared_he_he);
2361 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2366 const int flags_masked = k_flags & HVhek_MASK;
2367 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2368 if (HeHASH(entry) != hash) /* strings can't be equal */
2370 if (HeKLEN(entry) != len)
2372 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2374 if (HeKFLAGS(entry) != flags_masked)
2381 if (--entry->he_valu.hent_refcount == 0) {
2382 *oentry = HeNEXT(entry);
2384 /* There are now no entries in our slot. */
2385 xhv->xhv_fill--; /* HvFILL(hv)-- */
2388 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2392 UNLOCK_STRTAB_MUTEX;
2393 if (!entry && ckWARN_d(WARN_INTERNAL))
2394 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2395 "Attempt to free non-existent shared string '%s'%s"
2397 hek ? HEK_KEY(hek) : str,
2398 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2399 if (k_flags & HVhek_FREEKEY)
2403 /* get a (constant) string ptr from the global string table
2404 * string will get added if it is not already there.
2405 * len and hash must both be valid for str.
2408 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2410 bool is_utf8 = FALSE;
2412 const char * const save = str;
2415 STRLEN tmplen = -len;
2417 /* See the note in hv_fetch(). --jhi */
2418 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2420 /* If we were able to downgrade here, then than means that we were passed
2421 in a key which only had chars 0-255, but was utf8 encoded. */
2424 /* If we found we were able to downgrade the string to bytes, then
2425 we should flag that it needs upgrading on keys or each. Also flag
2426 that we need share_hek_flags to free the string. */
2428 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2431 return share_hek_flags (str, len, hash, flags);
2435 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2439 const int flags_masked = flags & HVhek_MASK;
2440 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2442 /* what follows is the moral equivalent of:
2444 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2445 hv_store(PL_strtab, str, len, NULL, hash);
2447 Can't rehash the shared string table, so not sure if it's worth
2448 counting the number of entries in the linked list
2450 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2451 /* assert(xhv_array != 0) */
2453 entry = (HvARRAY(PL_strtab))[hindex];
2454 for (;entry; entry = HeNEXT(entry)) {
2455 if (HeHASH(entry) != hash) /* strings can't be equal */
2457 if (HeKLEN(entry) != len)
2459 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2461 if (HeKFLAGS(entry) != flags_masked)
2467 /* What used to be head of the list.
2468 If this is NULL, then we're the first entry for this slot, which
2469 means we need to increate fill. */
2470 struct shared_he *new_entry;
2473 HE **const head = &HvARRAY(PL_strtab)[hindex];
2474 HE *const next = *head;
2476 /* We don't actually store a HE from the arena and a regular HEK.
2477 Instead we allocate one chunk of memory big enough for both,
2478 and put the HEK straight after the HE. This way we can find the
2479 HEK directly from the HE.
2482 Newx(k, STRUCT_OFFSET(struct shared_he,
2483 shared_he_hek.hek_key[0]) + len + 2, char);
2484 new_entry = (struct shared_he *)k;
2485 entry = &(new_entry->shared_he_he);
2486 hek = &(new_entry->shared_he_hek);
2488 Copy(str, HEK_KEY(hek), len, char);
2489 HEK_KEY(hek)[len] = 0;
2491 HEK_HASH(hek) = hash;
2492 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2494 /* Still "point" to the HEK, so that other code need not know what
2496 HeKEY_hek(entry) = hek;
2497 entry->he_valu.hent_refcount = 0;
2498 HeNEXT(entry) = next;
2501 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2502 if (!next) { /* initial entry? */
2503 xhv->xhv_fill++; /* HvFILL(hv)++ */
2504 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2509 ++entry->he_valu.hent_refcount;
2510 UNLOCK_STRTAB_MUTEX;
2512 if (flags & HVhek_FREEKEY)
2515 return HeKEY_hek(entry);
2519 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2522 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2523 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2524 if (uf->uf_set == NULL) {
2525 SV* obj = mg->mg_obj;
2526 mg->mg_obj = keysv; /* pass key */
2527 uf->uf_index = action; /* pass action */
2528 magic_getuvar((SV*)hv, mg);
2529 keysv = mg->mg_obj; /* may have changed */
2537 Perl_hv_placeholders_p(pTHX_ HV *hv)
2540 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2543 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2546 Perl_die(aTHX_ "panic: hv_placeholders_p");
2549 return &(mg->mg_len);
2554 Perl_hv_placeholders_get(pTHX_ HV *hv)
2557 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2559 return mg ? mg->mg_len : 0;
2563 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2566 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2571 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2572 Perl_die(aTHX_ "panic: hv_placeholders_set");
2574 /* else we don't need to add magic to record 0 placeholders. */
2578 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2582 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2587 value = &PL_sv_placeholder;
2590 value = (he->refcounted_he_data[0] & HVrhek_UV)
2591 ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
2592 : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
2595 /* Create a string SV that directly points to the bytes in our
2598 sv_upgrade(value, SVt_PV);
2599 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2600 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2601 /* This stops anything trying to free it */
2602 SvLEN_set(value, 0);
2604 SvREADONLY_on(value);
2605 if (he->refcounted_he_data[0] & HVrhek_UTF8)
2609 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2610 he->refcounted_he_data[0]);
2616 /* A big expression to find the key offset */
2617 #define REF_HE_KEY(chain) \
2618 ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
2619 ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
2620 + 1 + chain->refcounted_he_data)
2624 =for apidoc refcounted_he_chain_2hv
2626 Generates an returns a C<HV *> by walking up the tree starting at the passed
2627 in C<struct refcounted_he *>.
2632 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2636 U32 placeholders = 0;
2637 /* We could chase the chain once to get an idea of the number of keys,
2638 and call ksplit. But for now we'll make a potentially inefficient
2639 hash with only 8 entries in its array. */
2640 const U32 max = HvMAX(hv);
2644 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2645 HvARRAY(hv) = (HE**)array;
2650 U32 hash = chain->refcounted_he_hash;
2652 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2654 HE **oentry = &((HvARRAY(hv))[hash & max]);
2655 HE *entry = *oentry;
2658 for (; entry; entry = HeNEXT(entry)) {
2659 if (HeHASH(entry) == hash) {
2660 /* We might have a duplicate key here. If so, entry is older
2661 than the key we've already put in the hash, so if they are
2662 the same, skip adding entry. */
2664 const STRLEN klen = HeKLEN(entry);
2665 const char *const key = HeKEY(entry);
2666 if (klen == chain->refcounted_he_keylen
2667 && (!!HeKUTF8(entry)
2668 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2669 && memEQ(key, REF_HE_KEY(chain), klen))
2672 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2674 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2675 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2676 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2687 = share_hek_flags(REF_HE_KEY(chain),
2688 chain->refcounted_he_keylen,
2689 chain->refcounted_he_hash,
2690 (chain->refcounted_he_data[0]
2691 & (HVhek_UTF8|HVhek_WASUTF8)));
2693 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2695 value = refcounted_he_value(chain);
2696 if (value == &PL_sv_placeholder)
2698 HeVAL(entry) = value;
2700 /* Link it into the chain. */
2701 HeNEXT(entry) = *oentry;
2702 if (!HeNEXT(entry)) {
2703 /* initial entry. */
2711 chain = chain->refcounted_he_next;
2715 clear_placeholders(hv, placeholders);
2716 HvTOTALKEYS(hv) -= placeholders;
2719 /* We could check in the loop to see if we encounter any keys with key
2720 flags, but it's probably not worth it, as this per-hash flag is only
2721 really meant as an optimisation for things like Storable. */
2723 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2729 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2730 const char *key, STRLEN klen, int flags, U32 hash)
2733 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2734 of your key has to exactly match that which is stored. */
2735 SV *value = &PL_sv_placeholder;
2739 if (flags & HVhek_FREEKEY)
2741 key = SvPV_const(keysv, klen);
2743 is_utf8 = (SvUTF8(keysv) != 0);
2745 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2749 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2750 hash = SvSHARED_HASH(keysv);
2752 PERL_HASH(hash, key, klen);
2756 for (; chain; chain = chain->refcounted_he_next) {
2758 if (hash != chain->refcounted_he_hash)
2760 if (klen != chain->refcounted_he_keylen)
2762 if (memNE(REF_HE_KEY(chain),key,klen))
2764 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2767 if (hash != HEK_HASH(chain->refcounted_he_hek))
2769 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2771 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2773 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2777 value = sv_2mortal(refcounted_he_value(chain));
2781 if (flags & HVhek_FREEKEY)
2788 =for apidoc refcounted_he_new
2790 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2791 stored in a compact form, all references remain the property of the caller.
2792 The C<struct refcounted_he> is returned with a reference count of 1.
2797 struct refcounted_he *
2798 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2799 SV *const key, SV *const value) {
2801 struct refcounted_he *he;
2803 const char *key_p = SvPV_const(key, key_len);
2804 STRLEN value_len = 0;
2805 const char *value_p = NULL;
2810 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2813 value_type = HVrhek_PV;
2814 } else if (SvIOK(value)) {
2815 value_type = HVrhek_IV;
2816 } else if (value == &PL_sv_placeholder) {
2817 value_type = HVrhek_delete;
2818 } else if (!SvOK(value)) {
2819 value_type = HVrhek_undef;
2821 value_type = HVrhek_PV;
2824 if (value_type == HVrhek_PV) {
2825 value_p = SvPV_const(value, value_len);
2826 key_offset = value_len + 2;
2834 he = (struct refcounted_he*)
2835 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2839 he = (struct refcounted_he*)
2840 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2845 he->refcounted_he_next = parent;
2847 if (value_type == HVrhek_PV) {
2848 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2849 he->refcounted_he_val.refcounted_he_u_len = value_len;
2850 if (SvUTF8(value)) {
2851 flags |= HVrhek_UTF8;
2853 } else if (value_type == HVrhek_IV) {
2855 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2858 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2863 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2864 As we're going to be building hash keys from this value in future,
2865 normalise it now. */
2866 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2867 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2869 PERL_HASH(hash, key_p, key_len);
2872 he->refcounted_he_hash = hash;
2873 he->refcounted_he_keylen = key_len;
2874 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2876 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2879 if (flags & HVhek_WASUTF8) {
2880 /* If it was downgraded from UTF-8, then the pointer returned from
2881 bytes_from_utf8 is an allocated pointer that we must free. */
2885 he->refcounted_he_data[0] = flags;
2886 he->refcounted_he_refcnt = 1;
2892 =for apidoc refcounted_he_free
2894 Decrements the reference count of the passed in C<struct refcounted_he *>
2895 by one. If the reference count reaches zero the structure's memory is freed,
2896 and C<refcounted_he_free> iterates onto the parent node.
2902 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2904 PERL_UNUSED_CONTEXT;
2907 struct refcounted_he *copy;
2911 new_count = --he->refcounted_he_refcnt;
2912 HINTS_REFCNT_UNLOCK;
2918 #ifndef USE_ITHREADS
2919 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2922 he = he->refcounted_he_next;
2923 PerlMemShared_free(copy);
2928 =for apidoc hv_assert
2930 Check that a hash is in an internally consistent state.
2938 Perl_hv_assert(pTHX_ HV *hv)
2943 int placeholders = 0;
2946 const I32 riter = HvRITER_get(hv);
2947 HE *eiter = HvEITER_get(hv);
2949 (void)hv_iterinit(hv);
2951 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2952 /* sanity check the values */
2953 if (HeVAL(entry) == &PL_sv_placeholder)
2957 /* sanity check the keys */
2958 if (HeSVKEY(entry)) {
2959 NOOP; /* Don't know what to check on SV keys. */
2960 } else if (HeKUTF8(entry)) {
2962 if (HeKWASUTF8(entry)) {
2963 PerlIO_printf(Perl_debug_log,
2964 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2965 (int) HeKLEN(entry), HeKEY(entry));
2968 } else if (HeKWASUTF8(entry))
2971 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2972 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2973 const int nhashkeys = HvUSEDKEYS(hv);
2974 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2976 if (nhashkeys != real) {
2977 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2980 if (nhashplaceholders != placeholders) {
2981 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2985 if (withflags && ! HvHASKFLAGS(hv)) {
2986 PerlIO_printf(Perl_debug_log,
2987 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2994 HvRITER_set(hv, riter); /* Restore hash iterator state */
2995 HvEITER_set(hv, eiter);
3002 * c-indentation-style: bsd
3004 * indent-tabs-mode: t
3007 * ex: set ts=8 sts=4 sw=4 noet: