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];
79 #define new_HE() new_he()
82 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
83 PL_body_roots[HE_SVSLOT] = p; \
91 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
93 const int flags_masked = flags & HVhek_MASK;
97 Newx(k, HEK_BASESIZE + len + 2, char);
99 Copy(str, HEK_KEY(hek), len, char);
100 HEK_KEY(hek)[len] = 0;
102 HEK_HASH(hek) = hash;
103 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
105 if (flags & HVhek_FREEKEY)
110 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
114 Perl_free_tied_hv_pool(pTHX)
117 HE *he = PL_hv_fetch_ent_mh;
120 Safefree(HeKEY_hek(he));
124 PL_hv_fetch_ent_mh = NULL;
127 #if defined(USE_ITHREADS)
129 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
131 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
133 PERL_UNUSED_ARG(param);
136 /* We already shared this hash key. */
137 (void)share_hek_hek(shared);
141 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
142 HEK_HASH(source), HEK_FLAGS(source));
143 ptr_table_store(PL_ptr_table, source, shared);
149 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
155 /* look for it in the table first */
156 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
160 /* create anew and remember what it is */
162 ptr_table_store(PL_ptr_table, e, ret);
164 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
165 if (HeKLEN(e) == HEf_SVKEY) {
167 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
168 HeKEY_hek(ret) = (HEK*)k;
169 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
172 /* This is hek_dup inlined, which seems to be important for speed
174 HEK * const source = HeKEY_hek(e);
175 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
178 /* We already shared this hash key. */
179 (void)share_hek_hek(shared);
183 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
184 HEK_HASH(source), HEK_FLAGS(source));
185 ptr_table_store(PL_ptr_table, source, shared);
187 HeKEY_hek(ret) = shared;
190 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
192 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
195 #endif /* USE_ITHREADS */
198 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
201 SV * const sv = sv_newmortal();
202 if (!(flags & HVhek_FREEKEY)) {
203 sv_setpvn(sv, key, klen);
206 /* Need to free saved eventually assign to mortal SV */
207 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
208 sv_usepvn(sv, (char *) key, klen);
210 if (flags & HVhek_UTF8) {
213 Perl_croak(aTHX_ msg, SVfARG(sv));
216 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
219 #define HV_FETCH_ISSTORE 0x01
220 #define HV_FETCH_ISEXISTS 0x02
221 #define HV_FETCH_LVALUE 0x04
222 #define HV_FETCH_JUST_SV 0x08
227 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
228 the length of the key. The C<hash> parameter is the precomputed hash
229 value; if it is zero then Perl will compute it. The return value will be
230 NULL if the operation failed or if the value did not need to be actually
231 stored within the hash (as in the case of tied hashes). Otherwise it can
232 be dereferenced to get the original C<SV*>. Note that the caller is
233 responsible for suitably incrementing the reference count of C<val> before
234 the call, and decrementing it if the function returned NULL. Effectively
235 a successful hv_store takes ownership of one reference to C<val>. This is
236 usually what you want; a newly created SV has a reference count of one, so
237 if all your code does is create SVs then store them in a hash, hv_store
238 will own the only reference to the new SV, and your code doesn't need to do
239 anything further to tidy up. hv_store is not implemented as a call to
240 hv_store_ent, and does not create a temporary SV for the key, so if your
241 key data is not already in SV form then use hv_store in preference to
244 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
245 information on how to use this function on tied hashes.
251 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
264 hek = hv_fetch_common (hv, NULL, key, klen, flags,
265 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
266 return hek ? &HeVAL(hek) : NULL;
269 /* XXX This looks like an ideal candidate to inline */
271 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
272 register U32 hash, int flags)
274 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
275 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
276 return hek ? &HeVAL(hek) : NULL;
280 =for apidoc hv_store_ent
282 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
283 parameter is the precomputed hash value; if it is zero then Perl will
284 compute it. The return value is the new hash entry so created. It will be
285 NULL if the operation failed or if the value did not need to be actually
286 stored within the hash (as in the case of tied hashes). Otherwise the
287 contents of the return value can be accessed using the C<He?> macros
288 described here. Note that the caller is responsible for suitably
289 incrementing the reference count of C<val> before the call, and
290 decrementing it if the function returned NULL. Effectively a successful
291 hv_store_ent takes ownership of one reference to C<val>. This is
292 usually what you want; a newly created SV has a reference count of one, so
293 if all your code does is create SVs then store them in a hash, hv_store
294 will own the only reference to the new SV, and your code doesn't need to do
295 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
296 unlike C<val> it does not take ownership of it, so maintaining the correct
297 reference count on C<key> is entirely the caller's responsibility. hv_store
298 is not implemented as a call to hv_store_ent, and does not create a temporary
299 SV for the key, so if your key data is not already in SV form then use
300 hv_store in preference to hv_store_ent.
302 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
303 information on how to use this function on tied hashes.
308 /* XXX This looks like an ideal candidate to inline */
310 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
312 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
316 =for apidoc hv_exists
318 Returns a boolean indicating whether the specified hash key exists. The
319 C<klen> is the length of the key.
325 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
337 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
344 Returns the SV which corresponds to the specified key in the hash. The
345 C<klen> is the length of the key. If C<lval> is set then the fetch will be
346 part of a store. Check that the return value is non-null before
347 dereferencing it to an C<SV*>.
349 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
350 information on how to use this function on tied hashes.
356 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
369 hek = hv_fetch_common (hv, NULL, key, klen, flags,
370 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
372 return hek ? &HeVAL(hek) : NULL;
376 =for apidoc hv_exists_ent
378 Returns a boolean indicating whether the specified hash key exists. C<hash>
379 can be a valid precomputed hash value, or 0 to ask for it to be
385 /* XXX This looks like an ideal candidate to inline */
387 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
389 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
393 /* returns an HE * structure with the all fields set */
394 /* note that hent_val will be a mortal sv for MAGICAL hashes */
396 =for apidoc hv_fetch_ent
398 Returns the hash entry which corresponds to the specified key in the hash.
399 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
400 if you want the function to compute it. IF C<lval> is set then the fetch
401 will be part of a store. Make sure the return value is non-null before
402 accessing it. The return value when C<tb> is a tied hash is a pointer to a
403 static location, so be sure to make a copy of the structure if you need to
406 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
407 information on how to use this function on tied hashes.
413 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
415 return hv_fetch_common(hv, keysv, NULL, 0, 0,
416 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
420 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
421 int flags, int action, SV *val, register U32 hash)
435 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
436 keysv = hv_magic_uvar_xkey(hv, keysv, action);
437 if (flags & HVhek_FREEKEY)
439 key = SvPV_const(keysv, klen);
441 is_utf8 = (SvUTF8(keysv) != 0);
443 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
446 xhv = (XPVHV*)SvANY(hv);
448 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
449 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
451 /* XXX should be able to skimp on the HE/HEK here when
452 HV_FETCH_JUST_SV is true. */
454 keysv = newSVpvn(key, klen);
459 keysv = newSVsv(keysv);
462 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
464 /* grab a fake HE/HEK pair from the pool or make a new one */
465 entry = PL_hv_fetch_ent_mh;
467 PL_hv_fetch_ent_mh = HeNEXT(entry);
471 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
472 HeKEY_hek(entry) = (HEK*)k;
474 HeNEXT(entry) = NULL;
475 HeSVKEY_set(entry, keysv);
477 sv_upgrade(sv, SVt_PVLV);
479 /* so we can free entry when freeing sv */
480 LvTARG(sv) = (SV*)entry;
482 /* XXX remove at some point? */
483 if (flags & HVhek_FREEKEY)
488 #ifdef ENV_IS_CASELESS
489 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
491 for (i = 0; i < klen; ++i)
492 if (isLOWER(key[i])) {
493 /* Would be nice if we had a routine to do the
494 copy and upercase in a single pass through. */
495 const char * const nkey = strupr(savepvn(key,klen));
496 /* Note that this fetch is for nkey (the uppercased
497 key) whereas the store is for key (the original) */
498 entry = hv_fetch_common(hv, NULL, nkey, klen,
499 HVhek_FREEKEY, /* free nkey */
500 0 /* non-LVAL fetch */,
502 0 /* compute hash */);
503 if (!entry && (action & HV_FETCH_LVALUE)) {
504 /* This call will free key if necessary.
505 Do it this way to encourage compiler to tail
507 entry = hv_fetch_common(hv, keysv, key, klen,
508 flags, HV_FETCH_ISSTORE,
511 if (flags & HVhek_FREEKEY)
519 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
520 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
521 /* I don't understand why hv_exists_ent has svret and sv,
522 whereas hv_exists only had one. */
523 SV * const svret = sv_newmortal();
526 if (keysv || is_utf8) {
528 keysv = newSVpvn(key, klen);
531 keysv = newSVsv(keysv);
533 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
535 mg_copy((SV*)hv, sv, key, klen);
537 if (flags & HVhek_FREEKEY)
539 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
540 /* This cast somewhat evil, but I'm merely using NULL/
541 not NULL to return the boolean exists.
542 And I know hv is not NULL. */
543 return SvTRUE(svret) ? (HE *)hv : NULL;
545 #ifdef ENV_IS_CASELESS
546 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
547 /* XXX This code isn't UTF8 clean. */
548 char * const keysave = (char * const)key;
549 /* Will need to free this, so set FREEKEY flag. */
550 key = savepvn(key,klen);
551 key = (const char*)strupr((char*)key);
556 if (flags & HVhek_FREEKEY) {
559 flags |= HVhek_FREEKEY;
563 else if (action & HV_FETCH_ISSTORE) {
566 hv_magic_check (hv, &needs_copy, &needs_store);
568 const bool save_taint = PL_tainted;
569 if (keysv || is_utf8) {
571 keysv = newSVpvn(key, klen);
575 PL_tainted = SvTAINTED(keysv);
576 keysv = sv_2mortal(newSVsv(keysv));
577 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
579 mg_copy((SV*)hv, val, key, klen);
582 TAINT_IF(save_taint);
584 if (flags & HVhek_FREEKEY)
588 #ifdef ENV_IS_CASELESS
589 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
590 /* XXX This code isn't UTF8 clean. */
591 const char *keysave = key;
592 /* Will need to free this, so set FREEKEY flag. */
593 key = savepvn(key,klen);
594 key = (const char*)strupr((char*)key);
599 if (flags & HVhek_FREEKEY) {
602 flags |= HVhek_FREEKEY;
610 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
611 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
612 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
617 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
619 HvARRAY(hv) = (HE**)array;
621 #ifdef DYNAMIC_ENV_FETCH
622 else if (action & HV_FETCH_ISEXISTS) {
623 /* for an %ENV exists, if we do an insert it's by a recursive
624 store call, so avoid creating HvARRAY(hv) right now. */
628 /* XXX remove at some point? */
629 if (flags & HVhek_FREEKEY)
637 char * const keysave = (char *)key;
638 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
642 flags &= ~HVhek_UTF8;
643 if (key != keysave) {
644 if (flags & HVhek_FREEKEY)
646 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
651 PERL_HASH_INTERNAL(hash, key, klen);
652 /* We don't have a pointer to the hv, so we have to replicate the
653 flag into every HEK, so that hv_iterkeysv can see it. */
654 /* And yes, you do need this even though you are not "storing" because
655 you can flip the flags below if doing an lval lookup. (And that
656 was put in to give the semantics Andreas was expecting.) */
657 flags |= HVhek_REHASH;
659 if (keysv && (SvIsCOW_shared_hash(keysv))) {
660 hash = SvSHARED_HASH(keysv);
662 PERL_HASH(hash, key, klen);
666 masked_flags = (flags & HVhek_MASK);
668 #ifdef DYNAMIC_ENV_FETCH
669 if (!HvARRAY(hv)) entry = NULL;
673 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
675 for (; entry; entry = HeNEXT(entry)) {
676 if (HeHASH(entry) != hash) /* strings can't be equal */
678 if (HeKLEN(entry) != (I32)klen)
680 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
682 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
685 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
686 if (HeKFLAGS(entry) != masked_flags) {
687 /* We match if HVhek_UTF8 bit in our flags and hash key's
688 match. But if entry was set previously with HVhek_WASUTF8
689 and key now doesn't (or vice versa) then we should change
690 the key's flag, as this is assignment. */
691 if (HvSHAREKEYS(hv)) {
692 /* Need to swap the key we have for a key with the flags we
693 need. As keys are shared we can't just write to the
694 flag, so we share the new one, unshare the old one. */
695 HEK * const new_hek = share_hek_flags(key, klen, hash,
697 unshare_hek (HeKEY_hek(entry));
698 HeKEY_hek(entry) = new_hek;
700 else if (hv == PL_strtab) {
701 /* PL_strtab is usually the only hash without HvSHAREKEYS,
702 so putting this test here is cheap */
703 if (flags & HVhek_FREEKEY)
705 Perl_croak(aTHX_ S_strtab_error,
706 action & HV_FETCH_LVALUE ? "fetch" : "store");
709 HeKFLAGS(entry) = masked_flags;
710 if (masked_flags & HVhek_ENABLEHVKFLAGS)
713 if (HeVAL(entry) == &PL_sv_placeholder) {
714 /* yes, can store into placeholder slot */
715 if (action & HV_FETCH_LVALUE) {
717 /* This preserves behaviour with the old hv_fetch
718 implementation which at this point would bail out
719 with a break; (at "if we find a placeholder, we
720 pretend we haven't found anything")
722 That break mean that if a placeholder were found, it
723 caused a call into hv_store, which in turn would
724 check magic, and if there is no magic end up pretty
725 much back at this point (in hv_store's code). */
728 /* LVAL fetch which actaully needs a store. */
730 HvPLACEHOLDERS(hv)--;
733 if (val != &PL_sv_placeholder)
734 HvPLACEHOLDERS(hv)--;
737 } else if (action & HV_FETCH_ISSTORE) {
738 SvREFCNT_dec(HeVAL(entry));
741 } else if (HeVAL(entry) == &PL_sv_placeholder) {
742 /* if we find a placeholder, we pretend we haven't found
746 if (flags & HVhek_FREEKEY)
750 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
751 if (!(action & HV_FETCH_ISSTORE)
752 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
754 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
756 sv = newSVpvn(env,len);
758 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
764 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
765 hv_notallowed(flags, key, klen,
766 "Attempt to access disallowed key '%"SVf"' in"
767 " a restricted hash");
769 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
770 /* Not doing some form of store, so return failure. */
771 if (flags & HVhek_FREEKEY)
775 if (action & HV_FETCH_LVALUE) {
778 /* At this point the old hv_fetch code would call to hv_store,
779 which in turn might do some tied magic. So we need to make that
780 magic check happen. */
781 /* gonna assign to this, so it better be there */
782 return hv_fetch_common(hv, keysv, key, klen, flags,
783 HV_FETCH_ISSTORE, val, hash);
784 /* XXX Surely that could leak if the fetch-was-store fails?
785 Just like the hv_fetch. */
789 /* Welcome to hv_store... */
792 /* Not sure if we can get here. I think the only case of oentry being
793 NULL is for %ENV with dynamic env fetch. But that should disappear
794 with magic in the previous code. */
797 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
799 HvARRAY(hv) = (HE**)array;
802 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
805 /* share_hek_flags will do the free for us. This might be considered
808 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
809 else if (hv == PL_strtab) {
810 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
811 this test here is cheap */
812 if (flags & HVhek_FREEKEY)
814 Perl_croak(aTHX_ S_strtab_error,
815 action & HV_FETCH_LVALUE ? "fetch" : "store");
817 else /* gotta do the real thing */
818 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
820 HeNEXT(entry) = *oentry;
823 if (val == &PL_sv_placeholder)
824 HvPLACEHOLDERS(hv)++;
825 if (masked_flags & HVhek_ENABLEHVKFLAGS)
829 const HE *counter = HeNEXT(entry);
831 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
832 if (!counter) { /* initial entry? */
833 xhv->xhv_fill++; /* HvFILL(hv)++ */
834 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
836 } else if(!HvREHASH(hv)) {
839 while ((counter = HeNEXT(counter)))
842 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
843 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
844 bucket splits on a rehashed hash, as we're not going to
845 split it again, and if someone is lucky (evil) enough to
846 get all the keys in one list they could exhaust our memory
847 as we repeatedly double the number of buckets on every
848 entry. Linear search feels a less worse thing to do. */
858 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
860 const MAGIC *mg = SvMAGIC(hv);
864 if (isUPPER(mg->mg_type)) {
866 if (mg->mg_type == PERL_MAGIC_tied) {
867 *needs_store = FALSE;
868 return; /* We've set all there is to set. */
871 mg = mg->mg_moremagic;
876 =for apidoc hv_scalar
878 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
884 Perl_hv_scalar(pTHX_ HV *hv)
888 if (SvRMAGICAL(hv)) {
889 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
891 return magic_scalarpack(hv, mg);
896 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
897 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
905 =for apidoc hv_delete
907 Deletes a key/value pair in the hash. The value SV is removed from the
908 hash and returned to the caller. The C<klen> is the length of the key.
909 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
916 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
923 k_flags = HVhek_UTF8;
928 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
932 =for apidoc hv_delete_ent
934 Deletes a key/value pair in the hash. The value SV is removed from the
935 hash and returned to the caller. The C<flags> value will normally be zero;
936 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
937 precomputed hash value, or 0 to ask for it to be computed.
942 /* XXX This looks like an ideal candidate to inline */
944 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
946 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
950 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
951 int k_flags, I32 d_flags, U32 hash)
956 register HE **oentry;
957 HE *const *first_entry;
965 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
966 keysv = hv_magic_uvar_xkey(hv, keysv, -1);
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 (void*)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", (void*)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 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1615 HvHASKFLAGS_off(hv);
1619 HvEITER_set(hv, NULL);
1624 =for apidoc hv_clear_placeholders
1626 Clears any placeholders from a hash. If a restricted hash has any of its keys
1627 marked as readonly and the key is subsequently deleted, the key is not actually
1628 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1629 it so it will be ignored by future operations such as iterating over the hash,
1630 but will still allow the hash to have a value reassigned to the key at some
1631 future point. This function clears any such placeholder keys from the hash.
1632 See Hash::Util::lock_keys() for an example of its use.
1638 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1641 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1644 clear_placeholders(hv, items);
1648 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1658 /* Loop down the linked list heads */
1660 HE **oentry = &(HvARRAY(hv))[i];
1663 while ((entry = *oentry)) {
1664 if (HeVAL(entry) == &PL_sv_placeholder) {
1665 *oentry = HeNEXT(entry);
1666 if (first && !*oentry)
1667 HvFILL(hv)--; /* This linked list is now empty. */
1668 if (entry == HvEITER_get(hv))
1671 hv_free_ent(hv, entry);
1675 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1676 if (HvKEYS(hv) == 0)
1677 HvHASKFLAGS_off(hv);
1678 HvPLACEHOLDERS_set(hv, 0);
1682 oentry = &HeNEXT(entry);
1687 /* You can't get here, hence assertion should always fail. */
1688 assert (items == 0);
1693 S_hfreeentries(pTHX_ HV *hv)
1695 /* This is the array that we're going to restore */
1696 HE **const orig_array = HvARRAY(hv);
1704 /* If the hash is actually a symbol table with a name, look after the
1706 struct xpvhv_aux *iter = HvAUX(hv);
1708 name = iter->xhv_name;
1709 iter->xhv_name = NULL;
1714 /* orig_array remains unchanged throughout the loop. If after freeing all
1715 the entries it turns out that one of the little blighters has triggered
1716 an action that has caused HvARRAY to be re-allocated, then we set
1717 array to the new HvARRAY, and try again. */
1720 /* This is the one we're going to try to empty. First time round
1721 it's the original array. (Hopefully there will only be 1 time
1723 HE ** const array = HvARRAY(hv);
1726 /* Because we have taken xhv_name out, the only allocated pointer
1727 in the aux structure that might exist is the backreference array.
1732 struct xpvhv_aux *iter = HvAUX(hv);
1733 /* If there are weak references to this HV, we need to avoid
1734 freeing them up here. In particular we need to keep the AV
1735 visible as what we're deleting might well have weak references
1736 back to this HV, so the for loop below may well trigger
1737 the removal of backreferences from this array. */
1739 if (iter->xhv_backreferences) {
1740 /* So donate them to regular backref magic to keep them safe.
1741 The sv_magic will increase the reference count of the AV,
1742 so we need to drop it first. */
1743 SvREFCNT_dec(iter->xhv_backreferences);
1744 if (AvFILLp(iter->xhv_backreferences) == -1) {
1745 /* Turns out that the array is empty. Just free it. */
1746 SvREFCNT_dec(iter->xhv_backreferences);
1749 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1750 PERL_MAGIC_backref, NULL, 0);
1752 iter->xhv_backreferences = NULL;
1755 entry = iter->xhv_eiter; /* HvEITER(hv) */
1756 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1758 hv_free_ent(hv, entry);
1760 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1761 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1763 /* There are now no allocated pointers in the aux structure. */
1765 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1766 /* What aux structure? */
1769 /* make everyone else think the array is empty, so that the destructors
1770 * called for freed entries can't recusively mess with us */
1773 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1777 /* Loop down the linked list heads */
1778 HE *entry = array[i];
1781 register HE * const oentry = entry;
1782 entry = HeNEXT(entry);
1783 hv_free_ent(hv, oentry);
1787 /* As there are no allocated pointers in the aux structure, it's now
1788 safe to free the array we just cleaned up, if it's not the one we're
1789 going to put back. */
1790 if (array != orig_array) {
1795 /* Good. No-one added anything this time round. */
1800 /* Someone attempted to iterate or set the hash name while we had
1801 the array set to 0. We'll catch backferences on the next time
1802 round the while loop. */
1803 assert(HvARRAY(hv));
1805 if (HvAUX(hv)->xhv_name) {
1806 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1810 if (--attempts == 0) {
1811 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1815 HvARRAY(hv) = orig_array;
1817 /* If the hash was actually a symbol table, put the name back. */
1819 /* We have restored the original array. If name is non-NULL, then
1820 the original array had an aux structure at the end. So this is
1822 SvFLAGS(hv) |= SVf_OOK;
1823 HvAUX(hv)->xhv_name = name;
1828 =for apidoc hv_undef
1836 Perl_hv_undef(pTHX_ HV *hv)
1839 register XPVHV* xhv;
1844 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1845 xhv = (XPVHV*)SvANY(hv);
1847 if ((name = HvNAME_get(hv))) {
1849 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1850 hv_name_set(hv, NULL, 0, 0);
1852 SvFLAGS(hv) &= ~SVf_OOK;
1853 Safefree(HvARRAY(hv));
1854 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1856 HvPLACEHOLDERS_set(hv, 0);
1862 static struct xpvhv_aux*
1863 S_hv_auxinit(HV *hv) {
1864 struct xpvhv_aux *iter;
1868 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1869 + sizeof(struct xpvhv_aux), char);
1871 array = (char *) HvARRAY(hv);
1872 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1873 + sizeof(struct xpvhv_aux), char);
1875 HvARRAY(hv) = (HE**) array;
1876 /* SvOOK_on(hv) attacks the IV flags. */
1877 SvFLAGS(hv) |= SVf_OOK;
1880 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1881 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1883 iter->xhv_backreferences = 0;
1888 =for apidoc hv_iterinit
1890 Prepares a starting point to traverse a hash table. Returns the number of
1891 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1892 currently only meaningful for hashes without tie magic.
1894 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1895 hash buckets that happen to be in use. If you still need that esoteric
1896 value, you can get it through the macro C<HvFILL(tb)>.
1903 Perl_hv_iterinit(pTHX_ HV *hv)
1906 Perl_croak(aTHX_ "Bad hash");
1909 struct xpvhv_aux * const iter = HvAUX(hv);
1910 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1911 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1913 hv_free_ent(hv, entry);
1915 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1916 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1921 /* used to be xhv->xhv_fill before 5.004_65 */
1922 return HvTOTALKEYS(hv);
1926 Perl_hv_riter_p(pTHX_ HV *hv) {
1927 struct xpvhv_aux *iter;
1930 Perl_croak(aTHX_ "Bad hash");
1932 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1933 return &(iter->xhv_riter);
1937 Perl_hv_eiter_p(pTHX_ HV *hv) {
1938 struct xpvhv_aux *iter;
1941 Perl_croak(aTHX_ "Bad hash");
1943 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1944 return &(iter->xhv_eiter);
1948 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1949 struct xpvhv_aux *iter;
1952 Perl_croak(aTHX_ "Bad hash");
1960 iter = hv_auxinit(hv);
1962 iter->xhv_riter = riter;
1966 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1967 struct xpvhv_aux *iter;
1970 Perl_croak(aTHX_ "Bad hash");
1975 /* 0 is the default so don't go malloc()ing a new structure just to
1980 iter = hv_auxinit(hv);
1982 iter->xhv_eiter = eiter;
1986 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1989 struct xpvhv_aux *iter;
1992 PERL_UNUSED_ARG(flags);
1995 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1999 if (iter->xhv_name) {
2000 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2006 iter = hv_auxinit(hv);
2008 PERL_HASH(hash, name, len);
2009 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2013 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2014 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2015 PERL_UNUSED_CONTEXT;
2016 return &(iter->xhv_backreferences);
2020 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2026 av = HvAUX(hv)->xhv_backreferences;
2029 HvAUX(hv)->xhv_backreferences = 0;
2030 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2035 hv_iternext is implemented as a macro in hv.h
2037 =for apidoc hv_iternext
2039 Returns entries from a hash iterator. See C<hv_iterinit>.
2041 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2042 iterator currently points to, without losing your place or invalidating your
2043 iterator. Note that in this case the current entry is deleted from the hash
2044 with your iterator holding the last reference to it. Your iterator is flagged
2045 to free the entry on the next call to C<hv_iternext>, so you must not discard
2046 your iterator immediately else the entry will leak - call C<hv_iternext> to
2047 trigger the resource deallocation.
2049 =for apidoc hv_iternext_flags
2051 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2052 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2053 set the placeholders keys (for restricted hashes) will be returned in addition
2054 to normal keys. By default placeholders are automatically skipped over.
2055 Currently a placeholder is implemented with a value that is
2056 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2057 restricted hashes may change, and the implementation currently is
2058 insufficiently abstracted for any change to be tidy.
2064 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2067 register XPVHV* xhv;
2071 struct xpvhv_aux *iter;
2074 Perl_croak(aTHX_ "Bad hash");
2076 xhv = (XPVHV*)SvANY(hv);
2079 /* Too many things (well, pp_each at least) merrily assume that you can
2080 call iv_iternext without calling hv_iterinit, so we'll have to deal
2086 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2087 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2088 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2089 SV * const key = sv_newmortal();
2091 sv_setsv(key, HeSVKEY_force(entry));
2092 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2098 /* one HE per MAGICAL hash */
2099 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2101 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2103 HeKEY_hek(entry) = hek;
2104 HeKLEN(entry) = HEf_SVKEY;
2106 magic_nextpack((SV*) hv,mg,key);
2108 /* force key to stay around until next time */
2109 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2110 return entry; /* beware, hent_val is not set */
2113 SvREFCNT_dec(HeVAL(entry));
2114 Safefree(HeKEY_hek(entry));
2116 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2120 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* 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", (void*)hv, (void*)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;
2310 bool is_utf8 = FALSE;
2312 const char * const save = str;
2313 struct shared_he *he = NULL;
2316 /* Find the shared he which is just before us in memory. */
2317 he = (struct shared_he *)(((char *)hek)
2318 - STRUCT_OFFSET(struct shared_he,
2321 /* Assert that the caller passed us a genuine (or at least consistent)
2323 assert (he->shared_he_he.hent_hek == hek);
2326 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2327 --he->shared_he_he.he_valu.hent_refcount;
2328 UNLOCK_STRTAB_MUTEX;
2331 UNLOCK_STRTAB_MUTEX;
2333 hash = HEK_HASH(hek);
2334 } else if (len < 0) {
2335 STRLEN tmplen = -len;
2337 /* See the note in hv_fetch(). --jhi */
2338 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2341 k_flags = HVhek_UTF8;
2343 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2346 /* what follows was the moral equivalent of:
2347 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2349 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2351 xhv = (XPVHV*)SvANY(PL_strtab);
2352 /* assert(xhv_array != 0) */
2354 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2356 const HE *const he_he = &(he->shared_he_he);
2357 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2362 const int flags_masked = k_flags & HVhek_MASK;
2363 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2364 if (HeHASH(entry) != hash) /* strings can't be equal */
2366 if (HeKLEN(entry) != len)
2368 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2370 if (HeKFLAGS(entry) != flags_masked)
2377 if (--entry->he_valu.hent_refcount == 0) {
2378 *oentry = HeNEXT(entry);
2380 /* There are now no entries in our slot. */
2381 xhv->xhv_fill--; /* HvFILL(hv)-- */
2384 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2388 UNLOCK_STRTAB_MUTEX;
2389 if (!entry && ckWARN_d(WARN_INTERNAL))
2390 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2391 "Attempt to free non-existent shared string '%s'%s"
2393 hek ? HEK_KEY(hek) : str,
2394 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2395 if (k_flags & HVhek_FREEKEY)
2399 /* get a (constant) string ptr from the global string table
2400 * string will get added if it is not already there.
2401 * len and hash must both be valid for str.
2404 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2406 bool is_utf8 = FALSE;
2408 const char * const save = str;
2411 STRLEN tmplen = -len;
2413 /* See the note in hv_fetch(). --jhi */
2414 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2416 /* If we were able to downgrade here, then than means that we were passed
2417 in a key which only had chars 0-255, but was utf8 encoded. */
2420 /* If we found we were able to downgrade the string to bytes, then
2421 we should flag that it needs upgrading on keys or each. Also flag
2422 that we need share_hek_flags to free the string. */
2424 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2427 return share_hek_flags (str, len, hash, flags);
2431 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2435 const int flags_masked = flags & HVhek_MASK;
2436 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2438 /* what follows is the moral equivalent of:
2440 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2441 hv_store(PL_strtab, str, len, NULL, hash);
2443 Can't rehash the shared string table, so not sure if it's worth
2444 counting the number of entries in the linked list
2446 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2447 /* assert(xhv_array != 0) */
2449 entry = (HvARRAY(PL_strtab))[hindex];
2450 for (;entry; entry = HeNEXT(entry)) {
2451 if (HeHASH(entry) != hash) /* strings can't be equal */
2453 if (HeKLEN(entry) != len)
2455 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2457 if (HeKFLAGS(entry) != flags_masked)
2463 /* What used to be head of the list.
2464 If this is NULL, then we're the first entry for this slot, which
2465 means we need to increate fill. */
2466 struct shared_he *new_entry;
2469 HE **const head = &HvARRAY(PL_strtab)[hindex];
2470 HE *const next = *head;
2472 /* We don't actually store a HE from the arena and a regular HEK.
2473 Instead we allocate one chunk of memory big enough for both,
2474 and put the HEK straight after the HE. This way we can find the
2475 HEK directly from the HE.
2478 Newx(k, STRUCT_OFFSET(struct shared_he,
2479 shared_he_hek.hek_key[0]) + len + 2, char);
2480 new_entry = (struct shared_he *)k;
2481 entry = &(new_entry->shared_he_he);
2482 hek = &(new_entry->shared_he_hek);
2484 Copy(str, HEK_KEY(hek), len, char);
2485 HEK_KEY(hek)[len] = 0;
2487 HEK_HASH(hek) = hash;
2488 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2490 /* Still "point" to the HEK, so that other code need not know what
2492 HeKEY_hek(entry) = hek;
2493 entry->he_valu.hent_refcount = 0;
2494 HeNEXT(entry) = next;
2497 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2498 if (!next) { /* initial entry? */
2499 xhv->xhv_fill++; /* HvFILL(hv)++ */
2500 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2505 ++entry->he_valu.hent_refcount;
2506 UNLOCK_STRTAB_MUTEX;
2508 if (flags & HVhek_FREEKEY)
2511 return HeKEY_hek(entry);
2515 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2518 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2519 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2520 if (uf->uf_set == NULL) {
2521 SV* obj = mg->mg_obj;
2522 mg->mg_obj = keysv; /* pass key */
2523 uf->uf_index = action; /* pass action */
2524 magic_getuvar((SV*)hv, mg);
2525 keysv = mg->mg_obj; /* may have changed */
2533 Perl_hv_placeholders_p(pTHX_ HV *hv)
2536 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2539 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2542 Perl_die(aTHX_ "panic: hv_placeholders_p");
2545 return &(mg->mg_len);
2550 Perl_hv_placeholders_get(pTHX_ HV *hv)
2553 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2555 return mg ? mg->mg_len : 0;
2559 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2562 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2567 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2568 Perl_die(aTHX_ "panic: hv_placeholders_set");
2570 /* else we don't need to add magic to record 0 placeholders. */
2574 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2578 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2583 value = &PL_sv_placeholder;
2586 value = (he->refcounted_he_data[0] & HVrhek_UV)
2587 ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
2588 : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
2591 /* Create a string SV that directly points to the bytes in our
2594 sv_upgrade(value, SVt_PV);
2595 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2596 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2597 /* This stops anything trying to free it */
2598 SvLEN_set(value, 0);
2600 SvREADONLY_on(value);
2601 if (he->refcounted_he_data[0] & HVrhek_UTF8)
2605 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2606 he->refcounted_he_data[0]);
2612 /* A big expression to find the key offset */
2613 #define REF_HE_KEY(chain) \
2614 ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
2615 ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
2616 + 1 + chain->refcounted_he_data)
2620 =for apidoc refcounted_he_chain_2hv
2622 Generates an returns a C<HV *> by walking up the tree starting at the passed
2623 in C<struct refcounted_he *>.
2628 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2632 U32 placeholders = 0;
2633 /* We could chase the chain once to get an idea of the number of keys,
2634 and call ksplit. But for now we'll make a potentially inefficient
2635 hash with only 8 entries in its array. */
2636 const U32 max = HvMAX(hv);
2640 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2641 HvARRAY(hv) = (HE**)array;
2646 U32 hash = chain->refcounted_he_hash;
2648 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2650 HE **oentry = &((HvARRAY(hv))[hash & max]);
2651 HE *entry = *oentry;
2654 for (; entry; entry = HeNEXT(entry)) {
2655 if (HeHASH(entry) == hash) {
2656 /* We might have a duplicate key here. If so, entry is older
2657 than the key we've already put in the hash, so if they are
2658 the same, skip adding entry. */
2660 const STRLEN klen = HeKLEN(entry);
2661 const char *const key = HeKEY(entry);
2662 if (klen == chain->refcounted_he_keylen
2663 && (!!HeKUTF8(entry)
2664 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2665 && memEQ(key, REF_HE_KEY(chain), klen))
2668 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2670 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2671 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2672 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2683 = share_hek_flags(REF_HE_KEY(chain),
2684 chain->refcounted_he_keylen,
2685 chain->refcounted_he_hash,
2686 (chain->refcounted_he_data[0]
2687 & (HVhek_UTF8|HVhek_WASUTF8)));
2689 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2691 value = refcounted_he_value(chain);
2692 if (value == &PL_sv_placeholder)
2694 HeVAL(entry) = value;
2696 /* Link it into the chain. */
2697 HeNEXT(entry) = *oentry;
2698 if (!HeNEXT(entry)) {
2699 /* initial entry. */
2707 chain = chain->refcounted_he_next;
2711 clear_placeholders(hv, placeholders);
2712 HvTOTALKEYS(hv) -= placeholders;
2715 /* We could check in the loop to see if we encounter any keys with key
2716 flags, but it's probably not worth it, as this per-hash flag is only
2717 really meant as an optimisation for things like Storable. */
2719 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2725 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2726 const char *key, STRLEN klen, int flags, U32 hash)
2729 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2730 of your key has to exactly match that which is stored. */
2731 SV *value = &PL_sv_placeholder;
2735 if (flags & HVhek_FREEKEY)
2737 key = SvPV_const(keysv, klen);
2739 is_utf8 = (SvUTF8(keysv) != 0);
2741 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2745 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2746 hash = SvSHARED_HASH(keysv);
2748 PERL_HASH(hash, key, klen);
2752 for (; chain; chain = chain->refcounted_he_next) {
2754 if (hash != chain->refcounted_he_hash)
2756 if (klen != chain->refcounted_he_keylen)
2758 if (memNE(REF_HE_KEY(chain),key,klen))
2760 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2763 if (hash != HEK_HASH(chain->refcounted_he_hek))
2765 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2767 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2769 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2773 value = sv_2mortal(refcounted_he_value(chain));
2777 if (flags & HVhek_FREEKEY)
2784 =for apidoc refcounted_he_new
2786 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2787 stored in a compact form, all references remain the property of the caller.
2788 The C<struct refcounted_he> is returned with a reference count of 1.
2793 struct refcounted_he *
2794 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2795 SV *const key, SV *const value) {
2797 struct refcounted_he *he;
2799 const char *key_p = SvPV_const(key, key_len);
2800 STRLEN value_len = 0;
2801 const char *value_p = NULL;
2806 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2809 value_type = HVrhek_PV;
2810 } else if (SvIOK(value)) {
2811 value_type = HVrhek_IV;
2812 } else if (value == &PL_sv_placeholder) {
2813 value_type = HVrhek_delete;
2814 } else if (!SvOK(value)) {
2815 value_type = HVrhek_undef;
2817 value_type = HVrhek_PV;
2820 if (value_type == HVrhek_PV) {
2821 value_p = SvPV_const(value, value_len);
2822 key_offset = value_len + 2;
2830 he = (struct refcounted_he*)
2831 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2835 he = (struct refcounted_he*)
2836 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2841 he->refcounted_he_next = parent;
2843 if (value_type == HVrhek_PV) {
2844 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2845 he->refcounted_he_val.refcounted_he_u_len = value_len;
2846 if (SvUTF8(value)) {
2847 flags |= HVrhek_UTF8;
2849 } else if (value_type == HVrhek_IV) {
2851 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2854 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2859 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2860 As we're going to be building hash keys from this value in future,
2861 normalise it now. */
2862 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2863 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2865 PERL_HASH(hash, key_p, key_len);
2868 he->refcounted_he_hash = hash;
2869 he->refcounted_he_keylen = key_len;
2870 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2872 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2875 if (flags & HVhek_WASUTF8) {
2876 /* If it was downgraded from UTF-8, then the pointer returned from
2877 bytes_from_utf8 is an allocated pointer that we must free. */
2881 he->refcounted_he_data[0] = flags;
2882 he->refcounted_he_refcnt = 1;
2888 =for apidoc refcounted_he_free
2890 Decrements the reference count of the passed in C<struct refcounted_he *>
2891 by one. If the reference count reaches zero the structure's memory is freed,
2892 and C<refcounted_he_free> iterates onto the parent node.
2898 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2900 PERL_UNUSED_CONTEXT;
2903 struct refcounted_he *copy;
2907 new_count = --he->refcounted_he_refcnt;
2908 HINTS_REFCNT_UNLOCK;
2914 #ifndef USE_ITHREADS
2915 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2918 he = he->refcounted_he_next;
2919 PerlMemShared_free(copy);
2924 =for apidoc hv_assert
2926 Check that a hash is in an internally consistent state.
2934 Perl_hv_assert(pTHX_ HV *hv)
2939 int placeholders = 0;
2942 const I32 riter = HvRITER_get(hv);
2943 HE *eiter = HvEITER_get(hv);
2945 (void)hv_iterinit(hv);
2947 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2948 /* sanity check the values */
2949 if (HeVAL(entry) == &PL_sv_placeholder)
2953 /* sanity check the keys */
2954 if (HeSVKEY(entry)) {
2955 NOOP; /* Don't know what to check on SV keys. */
2956 } else if (HeKUTF8(entry)) {
2958 if (HeKWASUTF8(entry)) {
2959 PerlIO_printf(Perl_debug_log,
2960 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2961 (int) HeKLEN(entry), HeKEY(entry));
2964 } else if (HeKWASUTF8(entry))
2967 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2968 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2969 const int nhashkeys = HvUSEDKEYS(hv);
2970 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2972 if (nhashkeys != real) {
2973 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2976 if (nhashplaceholders != placeholders) {
2977 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2981 if (withflags && ! HvHASKFLAGS(hv)) {
2982 PerlIO_printf(Perl_debug_log,
2983 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2990 HvRITER_set(hv, riter); /* Restore hash iterator state */
2991 HvEITER_set(hv, eiter);
2998 * c-indentation-style: bsd
3000 * indent-tabs-mode: t
3003 * ex: set ts=8 sts=4 sw=4 noet: