3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 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);
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];
80 #define new_HE() new_he()
84 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
85 PL_body_roots[HE_SVSLOT] = p; \
94 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
96 const int flags_masked = flags & HVhek_MASK;
100 Newx(k, HEK_BASESIZE + len + 2, char);
102 Copy(str, HEK_KEY(hek), len, char);
103 HEK_KEY(hek)[len] = 0;
105 HEK_HASH(hek) = hash;
106 HEK_FLAGS(hek) = (unsigned char)flags_masked;
108 if (flags & HVhek_FREEKEY)
113 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
117 Perl_free_tied_hv_pool(pTHX)
120 HE *he = PL_hv_fetch_ent_mh;
123 Safefree(HeKEY_hek(he));
127 PL_hv_fetch_ent_mh = NULL;
130 #if defined(USE_ITHREADS)
132 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
134 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
136 PERL_UNUSED_ARG(param);
139 /* We already shared this hash key. */
140 (void)share_hek_hek(shared);
144 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
145 HEK_HASH(source), HEK_FLAGS(source));
146 ptr_table_store(PL_ptr_table, source, shared);
152 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
158 /* look for it in the table first */
159 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
163 /* create anew and remember what it is */
165 ptr_table_store(PL_ptr_table, e, ret);
167 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
168 if (HeKLEN(e) == HEf_SVKEY) {
170 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
171 HeKEY_hek(ret) = (HEK*)k;
172 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
175 /* This is hek_dup inlined, which seems to be important for speed
177 HEK * const source = HeKEY_hek(e);
178 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
181 /* We already shared this hash key. */
182 (void)share_hek_hek(shared);
186 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
187 HEK_HASH(source), HEK_FLAGS(source));
188 ptr_table_store(PL_ptr_table, source, shared);
190 HeKEY_hek(ret) = shared;
193 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
195 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
198 #endif /* USE_ITHREADS */
201 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
204 SV * const sv = sv_newmortal();
205 if (!(flags & HVhek_FREEKEY)) {
206 sv_setpvn(sv, key, klen);
209 /* Need to free saved eventually assign to mortal SV */
210 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
211 sv_usepvn(sv, (char *) key, klen);
213 if (flags & HVhek_UTF8) {
216 Perl_croak(aTHX_ msg, sv);
219 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
222 #define HV_FETCH_ISSTORE 0x01
223 #define HV_FETCH_ISEXISTS 0x02
224 #define HV_FETCH_LVALUE 0x04
225 #define HV_FETCH_JUST_SV 0x08
230 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
231 the length of the key. The C<hash> parameter is the precomputed hash
232 value; if it is zero then Perl will compute it. The return value will be
233 NULL if the operation failed or if the value did not need to be actually
234 stored within the hash (as in the case of tied hashes). Otherwise it can
235 be dereferenced to get the original C<SV*>. Note that the caller is
236 responsible for suitably incrementing the reference count of C<val> before
237 the call, and decrementing it if the function returned NULL. Effectively
238 a successful hv_store takes ownership of one reference to C<val>. This is
239 usually what you want; a newly created SV has a reference count of one, so
240 if all your code does is create SVs then store them in a hash, hv_store
241 will own the only reference to the new SV, and your code doesn't need to do
242 anything further to tidy up. hv_store is not implemented as a call to
243 hv_store_ent, and does not create a temporary SV for the key, so if your
244 key data is not already in SV form then use hv_store in preference to
247 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
248 information on how to use this function on tied hashes.
254 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
267 hek = hv_fetch_common (hv, NULL, key, klen, flags,
268 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
269 return hek ? &HeVAL(hek) : NULL;
272 /* XXX This looks like an ideal candidate to inline */
274 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
275 register U32 hash, int flags)
277 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
278 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
279 return hek ? &HeVAL(hek) : NULL;
283 =for apidoc hv_store_ent
285 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
286 parameter is the precomputed hash value; if it is zero then Perl will
287 compute it. The return value is the new hash entry so created. It will be
288 NULL if the operation failed or if the value did not need to be actually
289 stored within the hash (as in the case of tied hashes). Otherwise the
290 contents of the return value can be accessed using the C<He?> macros
291 described here. Note that the caller is responsible for suitably
292 incrementing the reference count of C<val> before the call, and
293 decrementing it if the function returned NULL. Effectively a successful
294 hv_store_ent takes ownership of one reference to C<val>. This is
295 usually what you want; a newly created SV has a reference count of one, so
296 if all your code does is create SVs then store them in a hash, hv_store
297 will own the only reference to the new SV, and your code doesn't need to do
298 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
299 unlike C<val> it does not take ownership of it, so maintaining the correct
300 reference count on C<key> is entirely the caller's responsibility. hv_store
301 is not implemented as a call to hv_store_ent, and does not create a temporary
302 SV for the key, so if your key data is not already in SV form then use
303 hv_store in preference to hv_store_ent.
305 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
306 information on how to use this function on tied hashes.
311 /* XXX This looks like an ideal candidate to inline */
313 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
315 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
319 =for apidoc hv_exists
321 Returns a boolean indicating whether the specified hash key exists. The
322 C<klen> is the length of the key.
328 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
340 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
347 Returns the SV which corresponds to the specified key in the hash. The
348 C<klen> is the length of the key. If C<lval> is set then the fetch will be
349 part of a store. Check that the return value is non-null before
350 dereferencing it to an C<SV*>.
352 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
353 information on how to use this function on tied hashes.
359 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
372 hek = hv_fetch_common (hv, NULL, key, klen, flags,
373 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
375 return hek ? &HeVAL(hek) : NULL;
379 =for apidoc hv_exists_ent
381 Returns a boolean indicating whether the specified hash key exists. C<hash>
382 can be a valid precomputed hash value, or 0 to ask for it to be
388 /* XXX This looks like an ideal candidate to inline */
390 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
392 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
396 /* returns an HE * structure with the all fields set */
397 /* note that hent_val will be a mortal sv for MAGICAL hashes */
399 =for apidoc hv_fetch_ent
401 Returns the hash entry which corresponds to the specified key in the hash.
402 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
403 if you want the function to compute it. IF C<lval> is set then the fetch
404 will be part of a store. Make sure the return value is non-null before
405 accessing it. The return value when C<tb> is a tied hash is a pointer to a
406 static location, so be sure to make a copy of the structure if you need to
409 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
410 information on how to use this function on tied hashes.
416 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
418 return hv_fetch_common(hv, keysv, NULL, 0, 0,
419 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
423 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
424 int flags, int action, SV *val, register U32 hash)
438 if (flags & HVhek_FREEKEY)
440 key = SvPV_const(keysv, klen);
442 is_utf8 = (SvUTF8(keysv) != 0);
444 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
447 xhv = (XPVHV*)SvANY(hv);
449 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
450 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
453 /* XXX should be able to skimp on the HE/HEK here when
454 HV_FETCH_JUST_SV is true. */
457 keysv = newSVpvn(key, klen);
462 keysv = newSVsv(keysv);
464 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
466 /* grab a fake HE/HEK pair from the pool or make a new one */
467 entry = PL_hv_fetch_ent_mh;
469 PL_hv_fetch_ent_mh = HeNEXT(entry);
473 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
474 HeKEY_hek(entry) = (HEK*)k;
476 HeNEXT(entry) = NULL;
477 HeSVKEY_set(entry, keysv);
479 sv_upgrade(sv, SVt_PVLV);
481 /* so we can free entry when freeing sv */
482 LvTARG(sv) = (SV*)entry;
484 /* XXX remove at some point? */
485 if (flags & HVhek_FREEKEY)
490 #ifdef ENV_IS_CASELESS
491 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
493 for (i = 0; i < klen; ++i)
494 if (isLOWER(key[i])) {
495 /* Would be nice if we had a routine to do the
496 copy and upercase in a single pass through. */
497 const char * const nkey = strupr(savepvn(key,klen));
498 /* Note that this fetch is for nkey (the uppercased
499 key) whereas the store is for key (the original) */
500 entry = hv_fetch_common(hv, NULL, nkey, klen,
501 HVhek_FREEKEY, /* free nkey */
502 0 /* non-LVAL fetch */,
504 0 /* compute hash */);
505 if (!entry && (action & HV_FETCH_LVALUE)) {
506 /* This call will free key if necessary.
507 Do it this way to encourage compiler to tail
509 entry = hv_fetch_common(hv, keysv, key, klen,
510 flags, HV_FETCH_ISSTORE,
513 if (flags & HVhek_FREEKEY)
521 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
522 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
523 /* I don't understand why hv_exists_ent has svret and sv,
524 whereas hv_exists only had one. */
525 SV * const svret = sv_newmortal();
528 if (keysv || is_utf8) {
530 keysv = newSVpvn(key, klen);
533 keysv = newSVsv(keysv);
535 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
537 mg_copy((SV*)hv, sv, key, klen);
539 if (flags & HVhek_FREEKEY)
541 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
542 /* This cast somewhat evil, but I'm merely using NULL/
543 not NULL to return the boolean exists.
544 And I know hv is not NULL. */
545 return SvTRUE(svret) ? (HE *)hv : NULL;
547 #ifdef ENV_IS_CASELESS
548 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
549 /* XXX This code isn't UTF8 clean. */
550 char * const keysave = (char * const)key;
551 /* Will need to free this, so set FREEKEY flag. */
552 key = savepvn(key,klen);
553 key = (const char*)strupr((char*)key);
558 if (flags & HVhek_FREEKEY) {
561 flags |= HVhek_FREEKEY;
565 else if (action & HV_FETCH_ISSTORE) {
568 hv_magic_check (hv, &needs_copy, &needs_store);
570 const bool save_taint = PL_tainted;
571 if (keysv || is_utf8) {
573 keysv = newSVpvn(key, klen);
577 PL_tainted = SvTAINTED(keysv);
578 keysv = sv_2mortal(newSVsv(keysv));
579 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
581 mg_copy((SV*)hv, val, key, klen);
584 TAINT_IF(save_taint);
586 if (flags & HVhek_FREEKEY)
590 #ifdef ENV_IS_CASELESS
591 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
592 /* XXX This code isn't UTF8 clean. */
593 const char *keysave = key;
594 /* Will need to free this, so set FREEKEY flag. */
595 key = savepvn(key,klen);
596 key = (const char*)strupr((char*)key);
601 if (flags & HVhek_FREEKEY) {
604 flags |= HVhek_FREEKEY;
612 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
613 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
614 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
619 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
621 HvARRAY(hv) = (HE**)array;
623 #ifdef DYNAMIC_ENV_FETCH
624 else if (action & HV_FETCH_ISEXISTS) {
625 /* for an %ENV exists, if we do an insert it's by a recursive
626 store call, so avoid creating HvARRAY(hv) right now. */
630 /* XXX remove at some point? */
631 if (flags & HVhek_FREEKEY)
639 char * const keysave = (char *)key;
640 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
644 flags &= ~HVhek_UTF8;
645 if (key != keysave) {
646 if (flags & HVhek_FREEKEY)
648 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
653 PERL_HASH_INTERNAL(hash, key, klen);
654 /* We don't have a pointer to the hv, so we have to replicate the
655 flag into every HEK, so that hv_iterkeysv can see it. */
656 /* And yes, you do need this even though you are not "storing" because
657 you can flip the flags below if doing an lval lookup. (And that
658 was put in to give the semantics Andreas was expecting.) */
659 flags |= HVhek_REHASH;
661 if (keysv && (SvIsCOW_shared_hash(keysv))) {
662 hash = SvSHARED_HASH(keysv);
664 PERL_HASH(hash, key, klen);
668 masked_flags = (flags & HVhek_MASK);
670 #ifdef DYNAMIC_ENV_FETCH
671 if (!HvARRAY(hv)) entry = NULL;
675 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
677 for (; entry; entry = HeNEXT(entry)) {
678 if (HeHASH(entry) != hash) /* strings can't be equal */
680 if (HeKLEN(entry) != (I32)klen)
682 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
684 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
687 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
688 if (HeKFLAGS(entry) != masked_flags) {
689 /* We match if HVhek_UTF8 bit in our flags and hash key's
690 match. But if entry was set previously with HVhek_WASUTF8
691 and key now doesn't (or vice versa) then we should change
692 the key's flag, as this is assignment. */
693 if (HvSHAREKEYS(hv)) {
694 /* Need to swap the key we have for a key with the flags we
695 need. As keys are shared we can't just write to the
696 flag, so we share the new one, unshare the old one. */
697 HEK * const new_hek = share_hek_flags(key, klen, hash,
699 unshare_hek (HeKEY_hek(entry));
700 HeKEY_hek(entry) = new_hek;
702 else if (hv == PL_strtab) {
703 /* PL_strtab is usually the only hash without HvSHAREKEYS,
704 so putting this test here is cheap */
705 if (flags & HVhek_FREEKEY)
707 Perl_croak(aTHX_ S_strtab_error,
708 action & HV_FETCH_LVALUE ? "fetch" : "store");
711 HeKFLAGS(entry) = masked_flags;
712 if (masked_flags & HVhek_ENABLEHVKFLAGS)
715 if (HeVAL(entry) == &PL_sv_placeholder) {
716 /* yes, can store into placeholder slot */
717 if (action & HV_FETCH_LVALUE) {
719 /* This preserves behaviour with the old hv_fetch
720 implementation which at this point would bail out
721 with a break; (at "if we find a placeholder, we
722 pretend we haven't found anything")
724 That break mean that if a placeholder were found, it
725 caused a call into hv_store, which in turn would
726 check magic, and if there is no magic end up pretty
727 much back at this point (in hv_store's code). */
730 /* LVAL fetch which actaully needs a store. */
732 HvPLACEHOLDERS(hv)--;
735 if (val != &PL_sv_placeholder)
736 HvPLACEHOLDERS(hv)--;
739 } else if (action & HV_FETCH_ISSTORE) {
740 SvREFCNT_dec(HeVAL(entry));
743 } else if (HeVAL(entry) == &PL_sv_placeholder) {
744 /* if we find a placeholder, we pretend we haven't found
748 if (flags & HVhek_FREEKEY)
752 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
753 if (!(action & HV_FETCH_ISSTORE)
754 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
756 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
758 sv = newSVpvn(env,len);
760 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
766 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
767 hv_notallowed(flags, key, klen,
768 "Attempt to access disallowed key '%"SVf"' in"
769 " a restricted hash");
771 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
772 /* Not doing some form of store, so return failure. */
773 if (flags & HVhek_FREEKEY)
777 if (action & HV_FETCH_LVALUE) {
780 /* At this point the old hv_fetch code would call to hv_store,
781 which in turn might do some tied magic. So we need to make that
782 magic check happen. */
783 /* gonna assign to this, so it better be there */
784 return hv_fetch_common(hv, keysv, key, klen, flags,
785 HV_FETCH_ISSTORE, val, hash);
786 /* XXX Surely that could leak if the fetch-was-store fails?
787 Just like the hv_fetch. */
791 /* Welcome to hv_store... */
794 /* Not sure if we can get here. I think the only case of oentry being
795 NULL is for %ENV with dynamic env fetch. But that should disappear
796 with magic in the previous code. */
799 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
801 HvARRAY(hv) = (HE**)array;
804 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
807 /* share_hek_flags will do the free for us. This might be considered
810 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
811 else if (hv == PL_strtab) {
812 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
813 this test here is cheap */
814 if (flags & HVhek_FREEKEY)
816 Perl_croak(aTHX_ S_strtab_error,
817 action & HV_FETCH_LVALUE ? "fetch" : "store");
819 else /* gotta do the real thing */
820 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
822 HeNEXT(entry) = *oentry;
825 if (val == &PL_sv_placeholder)
826 HvPLACEHOLDERS(hv)++;
827 if (masked_flags & HVhek_ENABLEHVKFLAGS)
831 const HE *counter = HeNEXT(entry);
833 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
834 if (!counter) { /* initial entry? */
835 xhv->xhv_fill++; /* HvFILL(hv)++ */
836 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
838 } else if(!HvREHASH(hv)) {
841 while ((counter = HeNEXT(counter)))
844 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
845 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
846 bucket splits on a rehashed hash, as we're not going to
847 split it again, and if someone is lucky (evil) enough to
848 get all the keys in one list they could exhaust our memory
849 as we repeatedly double the number of buckets on every
850 entry. Linear search feels a less worse thing to do. */
860 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
862 const MAGIC *mg = SvMAGIC(hv);
866 if (isUPPER(mg->mg_type)) {
868 if (mg->mg_type == PERL_MAGIC_tied) {
869 *needs_store = FALSE;
870 return; /* We've set all there is to set. */
873 mg = mg->mg_moremagic;
878 =for apidoc hv_scalar
880 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
886 Perl_hv_scalar(pTHX_ HV *hv)
890 if (SvRMAGICAL(hv)) {
891 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
893 return magic_scalarpack(hv, mg);
898 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
899 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
907 =for apidoc hv_delete
909 Deletes a key/value pair in the hash. The value SV is removed from the
910 hash and returned to the caller. The C<klen> is the length of the key.
911 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
918 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
925 k_flags = HVhek_UTF8;
930 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
934 =for apidoc hv_delete_ent
936 Deletes a key/value pair in the hash. The value SV is removed from the
937 hash and returned to the caller. The C<flags> value will normally be zero;
938 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
939 precomputed hash value, or 0 to ask for it to be computed.
944 /* XXX This looks like an ideal candidate to inline */
946 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
948 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
952 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
953 int k_flags, I32 d_flags, U32 hash)
958 register HE **oentry;
959 HE *const *first_entry;
967 if (k_flags & HVhek_FREEKEY)
969 key = SvPV_const(keysv, klen);
971 is_utf8 = (SvUTF8(keysv) != 0);
973 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
976 if (SvRMAGICAL(hv)) {
979 hv_magic_check (hv, &needs_copy, &needs_store);
983 entry = hv_fetch_common(hv, keysv, key, klen,
984 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
986 sv = entry ? HeVAL(entry) : NULL;
992 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
993 /* No longer an element */
994 sv_unmagic(sv, PERL_MAGIC_tiedelem);
997 return NULL; /* element cannot be deleted */
999 #ifdef ENV_IS_CASELESS
1000 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1001 /* XXX This code isn't UTF8 clean. */
1002 keysv = sv_2mortal(newSVpvn(key,klen));
1003 if (k_flags & HVhek_FREEKEY) {
1006 key = strupr(SvPVX(keysv));
1015 xhv = (XPVHV*)SvANY(hv);
1020 const char * const keysave = key;
1021 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1024 k_flags |= HVhek_UTF8;
1026 k_flags &= ~HVhek_UTF8;
1027 if (key != keysave) {
1028 if (k_flags & HVhek_FREEKEY) {
1029 /* This shouldn't happen if our caller does what we expect,
1030 but strictly the API allows it. */
1033 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1035 HvHASKFLAGS_on((SV*)hv);
1039 PERL_HASH_INTERNAL(hash, key, klen);
1041 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1042 hash = SvSHARED_HASH(keysv);
1044 PERL_HASH(hash, key, klen);
1048 masked_flags = (k_flags & HVhek_MASK);
1050 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1052 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1054 if (HeHASH(entry) != hash) /* strings can't be equal */
1056 if (HeKLEN(entry) != (I32)klen)
1058 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1060 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1063 if (hv == PL_strtab) {
1064 if (k_flags & HVhek_FREEKEY)
1066 Perl_croak(aTHX_ S_strtab_error, "delete");
1069 /* if placeholder is here, it's already been deleted.... */
1070 if (HeVAL(entry) == &PL_sv_placeholder) {
1071 if (k_flags & HVhek_FREEKEY)
1075 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1076 hv_notallowed(k_flags, key, klen,
1077 "Attempt to delete readonly key '%"SVf"' from"
1078 " a restricted hash");
1080 if (k_flags & HVhek_FREEKEY)
1083 if (d_flags & G_DISCARD)
1086 sv = sv_2mortal(HeVAL(entry));
1087 HeVAL(entry) = &PL_sv_placeholder;
1091 * If a restricted hash, rather than really deleting the entry, put
1092 * a placeholder there. This marks the key as being "approved", so
1093 * we can still access via not-really-existing key without raising
1096 if (SvREADONLY(hv)) {
1097 SvREFCNT_dec(HeVAL(entry));
1098 HeVAL(entry) = &PL_sv_placeholder;
1099 /* We'll be saving this slot, so the number of allocated keys
1100 * doesn't go down, but the number placeholders goes up */
1101 HvPLACEHOLDERS(hv)++;
1103 *oentry = HeNEXT(entry);
1105 xhv->xhv_fill--; /* HvFILL(hv)-- */
1107 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1110 hv_free_ent(hv, entry);
1111 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1112 if (xhv->xhv_keys == 0)
1113 HvHASKFLAGS_off(hv);
1117 if (SvREADONLY(hv)) {
1118 hv_notallowed(k_flags, key, klen,
1119 "Attempt to delete disallowed key '%"SVf"' from"
1120 " a restricted hash");
1123 if (k_flags & HVhek_FREEKEY)
1129 S_hsplit(pTHX_ HV *hv)
1132 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1133 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1134 register I32 newsize = oldsize * 2;
1136 char *a = (char*) HvARRAY(hv);
1138 register HE **oentry;
1139 int longest_chain = 0;
1142 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1143 hv, (int) oldsize);*/
1145 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1146 /* Can make this clear any placeholders first for non-restricted hashes,
1147 even though Storable rebuilds restricted hashes by putting in all the
1148 placeholders (first) before turning on the readonly flag, because
1149 Storable always pre-splits the hash. */
1150 hv_clear_placeholders(hv);
1154 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1155 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1156 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1162 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1165 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1166 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1171 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1173 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1175 if (oldsize >= 64) {
1176 offer_nice_chunk(HvARRAY(hv),
1177 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1178 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1181 Safefree(HvARRAY(hv));
1185 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1186 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1187 HvARRAY(hv) = (HE**) a;
1190 for (i=0; i<oldsize; i++,aep++) {
1191 int left_length = 0;
1192 int right_length = 0;
1196 if (!*aep) /* non-existent */
1199 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1200 if ((HeHASH(entry) & newsize) != (U32)i) {
1201 *oentry = HeNEXT(entry);
1202 HeNEXT(entry) = *bep;
1204 xhv->xhv_fill++; /* HvFILL(hv)++ */
1210 oentry = &HeNEXT(entry);
1214 if (!*aep) /* everything moved */
1215 xhv->xhv_fill--; /* HvFILL(hv)-- */
1216 /* I think we don't actually need to keep track of the longest length,
1217 merely flag if anything is too long. But for the moment while
1218 developing this code I'll track it. */
1219 if (left_length > longest_chain)
1220 longest_chain = left_length;
1221 if (right_length > longest_chain)
1222 longest_chain = right_length;
1226 /* Pick your policy for "hashing isn't working" here: */
1227 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1232 if (hv == PL_strtab) {
1233 /* Urg. Someone is doing something nasty to the string table.
1238 /* Awooga. Awooga. Pathological data. */
1239 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1240 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1243 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1244 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1246 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1249 was_shared = HvSHAREKEYS(hv);
1252 HvSHAREKEYS_off(hv);
1257 for (i=0; i<newsize; i++,aep++) {
1258 register HE *entry = *aep;
1260 /* We're going to trash this HE's next pointer when we chain it
1261 into the new hash below, so store where we go next. */
1262 HE * const next = HeNEXT(entry);
1267 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1272 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1273 hash, HeKFLAGS(entry));
1274 unshare_hek (HeKEY_hek(entry));
1275 HeKEY_hek(entry) = new_hek;
1277 /* Not shared, so simply write the new hash in. */
1278 HeHASH(entry) = hash;
1280 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1281 HEK_REHASH_on(HeKEY_hek(entry));
1282 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1284 /* Copy oentry to the correct new chain. */
1285 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1287 xhv->xhv_fill++; /* HvFILL(hv)++ */
1288 HeNEXT(entry) = *bep;
1294 Safefree (HvARRAY(hv));
1295 HvARRAY(hv) = (HE **)a;
1299 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1302 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1303 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1304 register I32 newsize;
1309 register HE **oentry;
1311 newsize = (I32) newmax; /* possible truncation here */
1312 if (newsize != newmax || newmax <= oldsize)
1314 while ((newsize & (1 + ~newsize)) != newsize) {
1315 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1317 if (newsize < newmax)
1319 if (newsize < newmax)
1320 return; /* overflow detection */
1322 a = (char *) HvARRAY(hv);
1325 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1326 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1327 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1333 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1336 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1337 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1342 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1344 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1346 if (oldsize >= 64) {
1347 offer_nice_chunk(HvARRAY(hv),
1348 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1349 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1352 Safefree(HvARRAY(hv));
1355 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1358 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1360 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1361 HvARRAY(hv) = (HE **) a;
1362 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1366 for (i=0; i<oldsize; i++,aep++) {
1367 if (!*aep) /* non-existent */
1369 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1370 register I32 j = (HeHASH(entry) & newsize);
1374 *oentry = HeNEXT(entry);
1375 if (!(HeNEXT(entry) = aep[j]))
1376 xhv->xhv_fill++; /* HvFILL(hv)++ */
1381 oentry = &HeNEXT(entry);
1383 if (!*aep) /* everything moved */
1384 xhv->xhv_fill--; /* HvFILL(hv)-- */
1391 Creates a new HV. The reference count is set to 1.
1399 register XPVHV* xhv;
1400 HV * const hv = (HV*)newSV(0);
1402 sv_upgrade((SV *)hv, SVt_PVHV);
1403 xhv = (XPVHV*)SvANY(hv);
1406 #ifndef NODEFAULT_SHAREKEYS
1407 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1410 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1411 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1416 Perl_newHVhv(pTHX_ HV *ohv)
1418 HV * const hv = newHV();
1419 STRLEN hv_max, hv_fill;
1421 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1423 hv_max = HvMAX(ohv);
1425 if (!SvMAGICAL((SV *)ohv)) {
1426 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1428 const bool shared = !!HvSHAREKEYS(ohv);
1429 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1431 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1434 /* In each bucket... */
1435 for (i = 0; i <= hv_max; i++) {
1437 HE *oent = oents[i];
1444 /* Copy the linked list of entries. */
1445 for (; oent; oent = HeNEXT(oent)) {
1446 const U32 hash = HeHASH(oent);
1447 const char * const key = HeKEY(oent);
1448 const STRLEN len = HeKLEN(oent);
1449 const int flags = HeKFLAGS(oent);
1450 HE * const ent = new_HE();
1452 HeVAL(ent) = newSVsv(HeVAL(oent));
1454 = shared ? share_hek_flags(key, len, hash, flags)
1455 : save_hek_flags(key, len, hash, flags);
1466 HvFILL(hv) = hv_fill;
1467 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1471 /* Iterate over ohv, copying keys and values one at a time. */
1473 const I32 riter = HvRITER_get(ohv);
1474 HE * const eiter = HvEITER_get(ohv);
1476 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1477 while (hv_max && hv_max + 1 >= hv_fill * 2)
1478 hv_max = hv_max / 2;
1482 while ((entry = hv_iternext_flags(ohv, 0))) {
1483 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1484 newSVsv(HeVAL(entry)), HeHASH(entry),
1487 HvRITER_set(ohv, riter);
1488 HvEITER_set(ohv, eiter);
1494 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1495 magic stays on it. */
1497 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1499 HV * const hv = newHV();
1502 if (ohv && (hv_fill = HvFILL(ohv))) {
1503 STRLEN hv_max = HvMAX(ohv);
1505 const I32 riter = HvRITER_get(ohv);
1506 HE * const eiter = HvEITER_get(ohv);
1508 while (hv_max && hv_max + 1 >= hv_fill * 2)
1509 hv_max = hv_max / 2;
1513 while ((entry = hv_iternext_flags(ohv, 0))) {
1514 SV *const sv = newSVsv(HeVAL(entry));
1515 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1516 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1517 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1518 sv, HeHASH(entry), HeKFLAGS(entry));
1520 HvRITER_set(ohv, riter);
1521 HvEITER_set(ohv, eiter);
1523 hv_magic(hv, NULL, PERL_MAGIC_hints);
1528 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1536 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1537 PL_sub_generation++; /* may be deletion of method from stash */
1539 if (HeKLEN(entry) == HEf_SVKEY) {
1540 SvREFCNT_dec(HeKEY_sv(entry));
1541 Safefree(HeKEY_hek(entry));
1543 else if (HvSHAREKEYS(hv))
1544 unshare_hek(HeKEY_hek(entry));
1546 Safefree(HeKEY_hek(entry));
1551 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1556 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1557 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1558 if (HeKLEN(entry) == HEf_SVKEY) {
1559 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1561 hv_free_ent(hv, entry);
1565 =for apidoc hv_clear
1567 Clears a hash, making it empty.
1573 Perl_hv_clear(pTHX_ HV *hv)
1576 register XPVHV* xhv;
1580 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1582 xhv = (XPVHV*)SvANY(hv);
1584 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1585 /* restricted hash: convert all keys to placeholders */
1587 for (i = 0; i <= xhv->xhv_max; i++) {
1588 HE *entry = (HvARRAY(hv))[i];
1589 for (; entry; entry = HeNEXT(entry)) {
1590 /* not already placeholder */
1591 if (HeVAL(entry) != &PL_sv_placeholder) {
1592 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1593 SV* const keysv = hv_iterkeysv(entry);
1595 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1598 SvREFCNT_dec(HeVAL(entry));
1599 HeVAL(entry) = &PL_sv_placeholder;
1600 HvPLACEHOLDERS(hv)++;
1608 HvPLACEHOLDERS_set(hv, 0);
1610 (void)memzero(HvARRAY(hv),
1611 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1616 HvHASKFLAGS_off(hv);
1620 HvEITER_set(hv, NULL);
1625 =for apidoc hv_clear_placeholders
1627 Clears any placeholders from a hash. If a restricted hash has any of its keys
1628 marked as readonly and the key is subsequently deleted, the key is not actually
1629 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1630 it so it will be ignored by future operations such as iterating over the hash,
1631 but will still allow the hash to have a value reassigned to the key at some
1632 future point. This function clears any such placeholder keys from the hash.
1633 See Hash::Util::lock_keys() for an example of its use.
1639 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1642 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1645 clear_placeholders(hv, items);
1649 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1659 /* Loop down the linked list heads */
1661 HE **oentry = &(HvARRAY(hv))[i];
1664 while ((entry = *oentry)) {
1665 if (HeVAL(entry) == &PL_sv_placeholder) {
1666 *oentry = HeNEXT(entry);
1667 if (first && !*oentry)
1668 HvFILL(hv)--; /* This linked list is now empty. */
1669 if (entry == HvEITER_get(hv))
1672 hv_free_ent(hv, entry);
1676 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1677 if (HvKEYS(hv) == 0)
1678 HvHASKFLAGS_off(hv);
1679 HvPLACEHOLDERS_set(hv, 0);
1683 oentry = &HeNEXT(entry);
1688 /* You can't get here, hence assertion should always fail. */
1689 assert (items == 0);
1694 S_hfreeentries(pTHX_ HV *hv)
1696 /* This is the array that we're going to restore */
1705 /* If the hash is actually a symbol table with a name, look after the
1707 struct xpvhv_aux *iter = HvAUX(hv);
1709 name = iter->xhv_name;
1710 iter->xhv_name = NULL;
1715 orig_array = HvARRAY(hv);
1716 /* orig_array remains unchanged throughout the loop. If after freeing all
1717 the entries it turns out that one of the little blighters has triggered
1718 an action that has caused HvARRAY to be re-allocated, then we set
1719 array to the new HvARRAY, and try again. */
1722 /* This is the one we're going to try to empty. First time round
1723 it's the original array. (Hopefully there will only be 1 time
1725 HE ** const array = HvARRAY(hv);
1728 /* Because we have taken xhv_name out, the only allocated pointer
1729 in the aux structure that might exist is the backreference array.
1734 struct xpvhv_aux *iter = HvAUX(hv);
1735 /* If there are weak references to this HV, we need to avoid
1736 freeing them up here. In particular we need to keep the AV
1737 visible as what we're deleting might well have weak references
1738 back to this HV, so the for loop below may well trigger
1739 the removal of backreferences from this array. */
1741 if (iter->xhv_backreferences) {
1742 /* So donate them to regular backref magic to keep them safe.
1743 The sv_magic will increase the reference count of the AV,
1744 so we need to drop it first. */
1745 SvREFCNT_dec(iter->xhv_backreferences);
1746 if (AvFILLp(iter->xhv_backreferences) == -1) {
1747 /* Turns out that the array is empty. Just free it. */
1748 SvREFCNT_dec(iter->xhv_backreferences);
1751 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1752 PERL_MAGIC_backref, NULL, 0);
1754 iter->xhv_backreferences = NULL;
1757 entry = iter->xhv_eiter; /* HvEITER(hv) */
1758 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1760 hv_free_ent(hv, entry);
1762 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1763 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1765 /* There are now no allocated pointers in the aux structure. */
1767 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1768 /* What aux structure? */
1771 /* make everyone else think the array is empty, so that the destructors
1772 * called for freed entries can't recusively mess with us */
1775 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1779 /* Loop down the linked list heads */
1780 HE *entry = array[i];
1783 register HE * const oentry = entry;
1784 entry = HeNEXT(entry);
1785 hv_free_ent(hv, oentry);
1789 /* As there are no allocated pointers in the aux structure, it's now
1790 safe to free the array we just cleaned up, if it's not the one we're
1791 going to put back. */
1792 if (array != orig_array) {
1797 /* Good. No-one added anything this time round. */
1802 /* Someone attempted to iterate or set the hash name while we had
1803 the array set to 0. We'll catch backferences on the next time
1804 round the while loop. */
1805 assert(HvARRAY(hv));
1807 if (HvAUX(hv)->xhv_name) {
1808 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1812 if (--attempts == 0) {
1813 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1817 HvARRAY(hv) = orig_array;
1819 /* If the hash was actually a symbol table, put the name back. */
1821 /* We have restored the original array. If name is non-NULL, then
1822 the original array had an aux structure at the end. So this is
1824 SvFLAGS(hv) |= SVf_OOK;
1825 HvAUX(hv)->xhv_name = name;
1830 =for apidoc hv_undef
1838 Perl_hv_undef(pTHX_ HV *hv)
1841 register XPVHV* xhv;
1846 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1847 xhv = (XPVHV*)SvANY(hv);
1849 if ((name = HvNAME_get(hv))) {
1851 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1852 hv_name_set(hv, NULL, 0, 0);
1854 SvFLAGS(hv) &= ~SVf_OOK;
1855 Safefree(HvARRAY(hv));
1856 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1858 HvPLACEHOLDERS_set(hv, 0);
1864 static struct xpvhv_aux*
1865 S_hv_auxinit(HV *hv) {
1866 struct xpvhv_aux *iter;
1870 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1871 + sizeof(struct xpvhv_aux), char);
1873 array = (char *) HvARRAY(hv);
1874 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1875 + sizeof(struct xpvhv_aux), char);
1877 HvARRAY(hv) = (HE**) array;
1878 /* SvOOK_on(hv) attacks the IV flags. */
1879 SvFLAGS(hv) |= SVf_OOK;
1882 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1883 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1885 iter->xhv_backreferences = 0;
1890 =for apidoc hv_iterinit
1892 Prepares a starting point to traverse a hash table. Returns the number of
1893 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1894 currently only meaningful for hashes without tie magic.
1896 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1897 hash buckets that happen to be in use. If you still need that esoteric
1898 value, you can get it through the macro C<HvFILL(tb)>.
1905 Perl_hv_iterinit(pTHX_ HV *hv)
1908 Perl_croak(aTHX_ "Bad hash");
1911 struct xpvhv_aux * const iter = HvAUX(hv);
1912 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1913 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1915 hv_free_ent(hv, entry);
1917 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1918 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1923 /* used to be xhv->xhv_fill before 5.004_65 */
1924 return HvTOTALKEYS(hv);
1928 Perl_hv_riter_p(pTHX_ HV *hv) {
1929 struct xpvhv_aux *iter;
1932 Perl_croak(aTHX_ "Bad hash");
1934 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1935 return &(iter->xhv_riter);
1939 Perl_hv_eiter_p(pTHX_ HV *hv) {
1940 struct xpvhv_aux *iter;
1943 Perl_croak(aTHX_ "Bad hash");
1945 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1946 return &(iter->xhv_eiter);
1950 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1951 struct xpvhv_aux *iter;
1954 Perl_croak(aTHX_ "Bad hash");
1962 iter = hv_auxinit(hv);
1964 iter->xhv_riter = riter;
1968 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1969 struct xpvhv_aux *iter;
1972 Perl_croak(aTHX_ "Bad hash");
1977 /* 0 is the default so don't go malloc()ing a new structure just to
1982 iter = hv_auxinit(hv);
1984 iter->xhv_eiter = eiter;
1988 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1991 struct xpvhv_aux *iter;
1994 PERL_UNUSED_ARG(flags);
1997 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2001 if (iter->xhv_name) {
2002 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2008 iter = hv_auxinit(hv);
2010 PERL_HASH(hash, name, len);
2011 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2015 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2016 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2017 PERL_UNUSED_CONTEXT;
2018 return &(iter->xhv_backreferences);
2022 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2028 av = HvAUX(hv)->xhv_backreferences;
2031 HvAUX(hv)->xhv_backreferences = 0;
2032 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2037 hv_iternext is implemented as a macro in hv.h
2039 =for apidoc hv_iternext
2041 Returns entries from a hash iterator. See C<hv_iterinit>.
2043 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2044 iterator currently points to, without losing your place or invalidating your
2045 iterator. Note that in this case the current entry is deleted from the hash
2046 with your iterator holding the last reference to it. Your iterator is flagged
2047 to free the entry on the next call to C<hv_iternext>, so you must not discard
2048 your iterator immediately else the entry will leak - call C<hv_iternext> to
2049 trigger the resource deallocation.
2051 =for apidoc hv_iternext_flags
2053 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2054 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2055 set the placeholders keys (for restricted hashes) will be returned in addition
2056 to normal keys. By default placeholders are automatically skipped over.
2057 Currently a placeholder is implemented with a value that is
2058 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2059 restricted hashes may change, and the implementation currently is
2060 insufficiently abstracted for any change to be tidy.
2066 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2069 register XPVHV* xhv;
2073 struct xpvhv_aux *iter;
2076 Perl_croak(aTHX_ "Bad hash");
2077 xhv = (XPVHV*)SvANY(hv);
2080 /* Too many things (well, pp_each at least) merrily assume that you can
2081 call iv_iternext without calling hv_iterinit, so we'll have to deal
2087 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2089 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
2090 SV * const key = sv_newmortal();
2092 sv_setsv(key, HeSVKEY_force(entry));
2093 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2099 /* one HE per MAGICAL hash */
2100 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2102 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2104 HeKEY_hek(entry) = hek;
2105 HeKLEN(entry) = HEf_SVKEY;
2107 magic_nextpack((SV*) hv,mg,key);
2109 /* force key to stay around until next time */
2110 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2111 return entry; /* beware, hent_val is not set */
2114 SvREFCNT_dec(HeVAL(entry));
2115 Safefree(HeKEY_hek(entry));
2117 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2120 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
2121 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2124 /* The prime_env_iter() on VMS just loaded up new hash values
2125 * so the iteration count needs to be reset back to the beginning
2129 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2134 /* hv_iterint now ensures this. */
2135 assert (HvARRAY(hv));
2137 /* At start of hash, entry is NULL. */
2140 entry = HeNEXT(entry);
2141 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2143 * Skip past any placeholders -- don't want to include them in
2146 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2147 entry = HeNEXT(entry);
2152 /* OK. Come to the end of the current list. Grab the next one. */
2154 iter->xhv_riter++; /* HvRITER(hv)++ */
2155 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2156 /* There is no next one. End of the hash. */
2157 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2160 entry = (HvARRAY(hv))[iter->xhv_riter];
2162 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2163 /* If we have an entry, but it's a placeholder, don't count it.
2165 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2166 entry = HeNEXT(entry);
2168 /* Will loop again if this linked list starts NULL
2169 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2170 or if we run through it and find only placeholders. */
2173 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2175 hv_free_ent(hv, oldentry);
2178 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2179 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
2181 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2186 =for apidoc hv_iterkey
2188 Returns the key from the current position of the hash iterator. See
2195 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2197 if (HeKLEN(entry) == HEf_SVKEY) {
2199 char * const p = SvPV(HeKEY_sv(entry), len);
2204 *retlen = HeKLEN(entry);
2205 return HeKEY(entry);
2209 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2211 =for apidoc hv_iterkeysv
2213 Returns the key as an C<SV*> from the current position of the hash
2214 iterator. The return value will always be a mortal copy of the key. Also
2221 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2223 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2227 =for apidoc hv_iterval
2229 Returns the value from the current position of the hash iterator. See
2236 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2238 if (SvRMAGICAL(hv)) {
2239 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2240 SV* const sv = sv_newmortal();
2241 if (HeKLEN(entry) == HEf_SVKEY)
2242 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2244 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2248 return HeVAL(entry);
2252 =for apidoc hv_iternextsv
2254 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2261 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2263 HE * const he = hv_iternext_flags(hv, 0);
2267 *key = hv_iterkey(he, retlen);
2268 return hv_iterval(hv, he);
2275 =for apidoc hv_magic
2277 Adds magic to a hash. See C<sv_magic>.
2282 /* possibly free a shared string if no one has access to it
2283 * len and hash must both be valid for str.
2286 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2288 unshare_hek_or_pvn (NULL, str, len, hash);
2293 Perl_unshare_hek(pTHX_ HEK *hek)
2295 unshare_hek_or_pvn(hek, NULL, 0, 0);
2298 /* possibly free a shared string if no one has access to it
2299 hek if non-NULL takes priority over the other 3, else str, len and hash
2300 are used. If so, len and hash must both be valid for str.
2303 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2306 register XPVHV* xhv;
2308 register HE **oentry;
2311 bool is_utf8 = FALSE;
2313 const char * const save = str;
2314 struct shared_he *he = NULL;
2317 /* Find the shared he which is just before us in memory. */
2318 he = (struct shared_he *)(((char *)hek)
2319 - STRUCT_OFFSET(struct shared_he,
2322 /* Assert that the caller passed us a genuine (or at least consistent)
2324 assert (he->shared_he_he.hent_hek == hek);
2327 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2328 --he->shared_he_he.he_valu.hent_refcount;
2329 UNLOCK_STRTAB_MUTEX;
2332 UNLOCK_STRTAB_MUTEX;
2334 hash = HEK_HASH(hek);
2335 } else if (len < 0) {
2336 STRLEN tmplen = -len;
2338 /* See the note in hv_fetch(). --jhi */
2339 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2342 k_flags = HVhek_UTF8;
2344 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2347 /* what follows was the moral equivalent of:
2348 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2350 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2352 xhv = (XPVHV*)SvANY(PL_strtab);
2353 /* assert(xhv_array != 0) */
2355 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2357 const HE *const he_he = &(he->shared_he_he);
2358 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2365 const int flags_masked = k_flags & HVhek_MASK;
2366 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2367 if (HeHASH(entry) != hash) /* strings can't be equal */
2369 if (HeKLEN(entry) != len)
2371 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2373 if (HeKFLAGS(entry) != flags_masked)
2381 if (--he->shared_he_he.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 (!found && 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 Perl_hv_placeholders_p(pTHX_ HV *hv)
2522 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2525 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2528 Perl_die(aTHX_ "panic: hv_placeholders_p");
2531 return &(mg->mg_len);
2536 Perl_hv_placeholders_get(pTHX_ HV *hv)
2539 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2541 return mg ? mg->mg_len : 0;
2545 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2548 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2553 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2554 Perl_die(aTHX_ "panic: hv_placeholders_set");
2556 /* else we don't need to add magic to record 0 placeholders. */
2560 =for apidoc refcounted_he_chain_2hv
2562 Generates an returns a C<HV *> by walking up the tree starting at the passed
2563 in C<struct refcounted_he *>.
2568 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2571 U32 placeholders = 0;
2572 /* We could chase the chain once to get an idea of the number of keys,
2573 and call ksplit. But for now we'll make a potentially inefficient
2574 hash with only 8 entries in its array. */
2575 const U32 max = HvMAX(hv);
2579 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2580 HvARRAY(hv) = (HE**)array;
2584 const U32 hash = HEK_HASH(chain->refcounted_he_he.hent_hek);
2585 HE **oentry = &((HvARRAY(hv))[hash & max]);
2586 HE *entry = *oentry;
2588 for (; entry; entry = HeNEXT(entry)) {
2589 if (HeHASH(entry) == hash) {
2596 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_he.hent_hek);
2598 HeVAL(entry) = chain->refcounted_he_he.he_valu.hent_val;
2599 if (HeVAL(entry) == &PL_sv_placeholder)
2601 SvREFCNT_inc_void_NN(HeVAL(entry));
2603 /* Link it into the chain. */
2604 HeNEXT(entry) = *oentry;
2605 if (!HeNEXT(entry)) {
2606 /* initial entry. */
2614 chain = (struct refcounted_he *) chain->refcounted_he_he.hent_next;
2618 clear_placeholders(hv, placeholders);
2619 HvTOTALKEYS(hv) -= placeholders;
2622 /* We could check in the loop to see if we encounter any keys with key
2623 flags, but it's probably not worth it, as this per-hash flag is only
2624 really meant as an optimisation for things like Storable. */
2626 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2632 =for apidoc refcounted_he_new
2634 Creates a new C<struct refcounted_he>. Assumes ownership of one reference
2635 to I<value>. As S<key> is copied into a shared hash key, all references remain
2636 the property of the caller. The C<struct refcounted_he> is returned with a
2637 reference count of 1.
2642 struct refcounted_he *
2643 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2644 SV *const key, SV *const value) {
2645 struct refcounted_he *he;
2648 const char *p = SvPV_const(key, len);
2650 PERL_HASH(hash, p, len);
2652 Newx(he, 1, struct refcounted_he);
2654 he->refcounted_he_he.hent_next = (HE *)parent;
2655 he->refcounted_he_he.he_valu.hent_val = value;
2656 he->refcounted_he_he.hent_hek
2657 = share_hek(p, SvUTF8(key) ? -(I32)len : len, hash);
2658 he->refcounted_he_refcnt = 1;
2664 =for apidoc refcounted_he_free
2666 Decrements the reference count of the passed in C<struct refcounted_he *>
2667 by one. If the reference count reaches zero the structure's memory is freed,
2668 and C<refcounted_he_free> iterates onto the parent node.
2674 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2676 struct refcounted_he *copy;
2678 if (--he->refcounted_he_refcnt)
2681 unshare_hek_or_pvn (he->refcounted_he_he.hent_hek, 0, 0, 0);
2682 SvREFCNT_dec(he->refcounted_he_he.he_valu.hent_val);
2684 he = (struct refcounted_he *) he->refcounted_he_he.hent_next;
2691 =for apidoc refcounted_he_dup
2693 Duplicates the C<struct refcounted_he *> for a new thread.
2698 #if defined(USE_ITHREADS)
2699 struct refcounted_he *
2700 Perl_refcounted_he_dup(pTHX_ const struct refcounted_he *const he,
2701 CLONE_PARAMS* param)
2703 struct refcounted_he *copy;
2708 /* look for it in the table first */
2709 copy = (struct refcounted_he *)ptr_table_fetch(PL_ptr_table, he);
2713 /* create anew and remember what it is */
2714 Newx(copy, 1, struct refcounted_he);
2715 ptr_table_store(PL_ptr_table, he, copy);
2717 copy->refcounted_he_he.hent_next
2718 = (HE *)Perl_refcounted_he_dup(aTHX_
2719 (struct refcounted_he *)
2720 he->refcounted_he_he.hent_next,
2722 copy->refcounted_he_he.he_valu.hent_val
2723 = SvREFCNT_inc(sv_dup(he->refcounted_he_he.he_valu.hent_val, param));
2724 copy->refcounted_he_he.hent_hek
2725 = hek_dup(he->refcounted_he_he.hent_hek, param);
2726 copy->refcounted_he_refcnt = he->refcounted_he_refcnt;
2731 =for apidoc refcounted_he_copy
2733 Copies a chain of C<struct refcounted_he *>. Used by C<pp_entereval>.
2738 struct refcounted_he *
2739 Perl_refcounted_he_copy(pTHX_ const struct refcounted_he * he)
2741 struct refcounted_he *copy;
2743 /* This is much easier to express recursively than iteratively. */
2747 Newx(copy, 1, struct refcounted_he);
2748 copy->refcounted_he_he.hent_next
2749 = (HE *)Perl_refcounted_he_copy(aTHX_
2750 (struct refcounted_he *)
2751 he->refcounted_he_he.hent_next);
2752 copy->refcounted_he_he.he_valu.hent_val
2753 = newSVsv(he->refcounted_he_he.he_valu.hent_val);
2754 hek = he->refcounted_he_he.hent_hek;
2755 copy->refcounted_he_he.hent_hek
2756 = share_hek(HEK_KEY(hek),
2757 HEK_UTF8(hek) ? -(I32)HEK_LEN(hek) : HEK_LEN(hek),
2759 copy->refcounted_he_refcnt = 1;
2765 =for apidoc hv_assert
2767 Check that a hash is in an internally consistent state.
2775 Perl_hv_assert(pTHX_ HV *hv)
2780 int placeholders = 0;
2783 const I32 riter = HvRITER_get(hv);
2784 HE *eiter = HvEITER_get(hv);
2786 (void)hv_iterinit(hv);
2788 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2789 /* sanity check the values */
2790 if (HeVAL(entry) == &PL_sv_placeholder) {
2795 /* sanity check the keys */
2796 if (HeSVKEY(entry)) {
2797 /*EMPTY*/ /* Don't know what to check on SV keys. */
2798 } else if (HeKUTF8(entry)) {
2800 if (HeKWASUTF8(entry)) {
2801 PerlIO_printf(Perl_debug_log,
2802 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2803 (int) HeKLEN(entry), HeKEY(entry));
2806 } else if (HeKWASUTF8(entry)) {
2810 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2811 if (HvUSEDKEYS(hv) != real) {
2812 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2813 (int) real, (int) HvUSEDKEYS(hv));
2816 if (HvPLACEHOLDERS_get(hv) != placeholders) {
2817 PerlIO_printf(Perl_debug_log,
2818 "Count %d placeholder(s), but hash reports %d\n",
2819 (int) placeholders, (int) HvPLACEHOLDERS_get(hv));
2823 if (withflags && ! HvHASKFLAGS(hv)) {
2824 PerlIO_printf(Perl_debug_log,
2825 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2832 HvRITER_set(hv, riter); /* Restore hash iterator state */
2833 HvEITER_set(hv, eiter);
2840 * c-indentation-style: bsd
2842 * indent-tabs-mode: t
2845 * ex: set ts=8 sts=4 sw=4 noet: