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_type(SVt_PVHV);
1401 xhv = (XPVHV*)SvANY(hv);
1403 #ifndef NODEFAULT_SHAREKEYS
1404 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1407 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1408 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1413 Perl_newHVhv(pTHX_ HV *ohv)
1415 HV * const hv = newHV();
1416 STRLEN hv_max, hv_fill;
1418 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1420 hv_max = HvMAX(ohv);
1422 if (!SvMAGICAL((SV *)ohv)) {
1423 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1425 const bool shared = !!HvSHAREKEYS(ohv);
1426 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1428 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1431 /* In each bucket... */
1432 for (i = 0; i <= hv_max; i++) {
1434 HE *oent = oents[i];
1441 /* Copy the linked list of entries. */
1442 for (; oent; oent = HeNEXT(oent)) {
1443 const U32 hash = HeHASH(oent);
1444 const char * const key = HeKEY(oent);
1445 const STRLEN len = HeKLEN(oent);
1446 const int flags = HeKFLAGS(oent);
1447 HE * const ent = new_HE();
1449 HeVAL(ent) = newSVsv(HeVAL(oent));
1451 = shared ? share_hek_flags(key, len, hash, flags)
1452 : save_hek_flags(key, len, hash, flags);
1463 HvFILL(hv) = hv_fill;
1464 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1468 /* Iterate over ohv, copying keys and values one at a time. */
1470 const I32 riter = HvRITER_get(ohv);
1471 HE * const eiter = HvEITER_get(ohv);
1473 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1474 while (hv_max && hv_max + 1 >= hv_fill * 2)
1475 hv_max = hv_max / 2;
1479 while ((entry = hv_iternext_flags(ohv, 0))) {
1480 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1481 newSVsv(HeVAL(entry)), HeHASH(entry),
1484 HvRITER_set(ohv, riter);
1485 HvEITER_set(ohv, eiter);
1491 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1492 magic stays on it. */
1494 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1496 HV * const hv = newHV();
1499 if (ohv && (hv_fill = HvFILL(ohv))) {
1500 STRLEN hv_max = HvMAX(ohv);
1502 const I32 riter = HvRITER_get(ohv);
1503 HE * const eiter = HvEITER_get(ohv);
1505 while (hv_max && hv_max + 1 >= hv_fill * 2)
1506 hv_max = hv_max / 2;
1510 while ((entry = hv_iternext_flags(ohv, 0))) {
1511 SV *const sv = newSVsv(HeVAL(entry));
1512 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1513 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1514 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1515 sv, HeHASH(entry), HeKFLAGS(entry));
1517 HvRITER_set(ohv, riter);
1518 HvEITER_set(ohv, eiter);
1520 hv_magic(hv, NULL, PERL_MAGIC_hints);
1525 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1533 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1534 PL_sub_generation++; /* may be deletion of method from stash */
1536 if (HeKLEN(entry) == HEf_SVKEY) {
1537 SvREFCNT_dec(HeKEY_sv(entry));
1538 Safefree(HeKEY_hek(entry));
1540 else if (HvSHAREKEYS(hv))
1541 unshare_hek(HeKEY_hek(entry));
1543 Safefree(HeKEY_hek(entry));
1548 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1553 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1554 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1555 if (HeKLEN(entry) == HEf_SVKEY) {
1556 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1558 hv_free_ent(hv, entry);
1562 =for apidoc hv_clear
1564 Clears a hash, making it empty.
1570 Perl_hv_clear(pTHX_ HV *hv)
1573 register XPVHV* xhv;
1577 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1579 xhv = (XPVHV*)SvANY(hv);
1581 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1582 /* restricted hash: convert all keys to placeholders */
1584 for (i = 0; i <= xhv->xhv_max; i++) {
1585 HE *entry = (HvARRAY(hv))[i];
1586 for (; entry; entry = HeNEXT(entry)) {
1587 /* not already placeholder */
1588 if (HeVAL(entry) != &PL_sv_placeholder) {
1589 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1590 SV* const keysv = hv_iterkeysv(entry);
1592 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1595 SvREFCNT_dec(HeVAL(entry));
1596 HeVAL(entry) = &PL_sv_placeholder;
1597 HvPLACEHOLDERS(hv)++;
1605 HvPLACEHOLDERS_set(hv, 0);
1607 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1612 HvHASKFLAGS_off(hv);
1616 HvEITER_set(hv, NULL);
1621 =for apidoc hv_clear_placeholders
1623 Clears any placeholders from a hash. If a restricted hash has any of its keys
1624 marked as readonly and the key is subsequently deleted, the key is not actually
1625 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1626 it so it will be ignored by future operations such as iterating over the hash,
1627 but will still allow the hash to have a value reassigned to the key at some
1628 future point. This function clears any such placeholder keys from the hash.
1629 See Hash::Util::lock_keys() for an example of its use.
1635 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1638 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1641 clear_placeholders(hv, items);
1645 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1655 /* Loop down the linked list heads */
1657 HE **oentry = &(HvARRAY(hv))[i];
1660 while ((entry = *oentry)) {
1661 if (HeVAL(entry) == &PL_sv_placeholder) {
1662 *oentry = HeNEXT(entry);
1663 if (first && !*oentry)
1664 HvFILL(hv)--; /* This linked list is now empty. */
1665 if (entry == HvEITER_get(hv))
1668 hv_free_ent(hv, entry);
1672 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1673 if (HvKEYS(hv) == 0)
1674 HvHASKFLAGS_off(hv);
1675 HvPLACEHOLDERS_set(hv, 0);
1679 oentry = &HeNEXT(entry);
1684 /* You can't get here, hence assertion should always fail. */
1685 assert (items == 0);
1690 S_hfreeentries(pTHX_ HV *hv)
1692 /* This is the array that we're going to restore */
1693 HE **const orig_array = HvARRAY(hv);
1701 /* If the hash is actually a symbol table with a name, look after the
1703 struct xpvhv_aux *iter = HvAUX(hv);
1705 name = iter->xhv_name;
1706 iter->xhv_name = NULL;
1711 /* orig_array remains unchanged throughout the loop. If after freeing all
1712 the entries it turns out that one of the little blighters has triggered
1713 an action that has caused HvARRAY to be re-allocated, then we set
1714 array to the new HvARRAY, and try again. */
1717 /* This is the one we're going to try to empty. First time round
1718 it's the original array. (Hopefully there will only be 1 time
1720 HE ** const array = HvARRAY(hv);
1723 /* Because we have taken xhv_name out, the only allocated pointer
1724 in the aux structure that might exist is the backreference array.
1729 struct xpvhv_aux *iter = HvAUX(hv);
1730 /* If there are weak references to this HV, we need to avoid
1731 freeing them up here. In particular we need to keep the AV
1732 visible as what we're deleting might well have weak references
1733 back to this HV, so the for loop below may well trigger
1734 the removal of backreferences from this array. */
1736 if (iter->xhv_backreferences) {
1737 /* So donate them to regular backref magic to keep them safe.
1738 The sv_magic will increase the reference count of the AV,
1739 so we need to drop it first. */
1740 SvREFCNT_dec(iter->xhv_backreferences);
1741 if (AvFILLp(iter->xhv_backreferences) == -1) {
1742 /* Turns out that the array is empty. Just free it. */
1743 SvREFCNT_dec(iter->xhv_backreferences);
1746 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1747 PERL_MAGIC_backref, NULL, 0);
1749 iter->xhv_backreferences = NULL;
1752 entry = iter->xhv_eiter; /* HvEITER(hv) */
1753 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1755 hv_free_ent(hv, entry);
1757 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1758 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1760 /* There are now no allocated pointers in the aux structure. */
1762 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1763 /* What aux structure? */
1766 /* make everyone else think the array is empty, so that the destructors
1767 * called for freed entries can't recusively mess with us */
1770 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1774 /* Loop down the linked list heads */
1775 HE *entry = array[i];
1778 register HE * const oentry = entry;
1779 entry = HeNEXT(entry);
1780 hv_free_ent(hv, oentry);
1784 /* As there are no allocated pointers in the aux structure, it's now
1785 safe to free the array we just cleaned up, if it's not the one we're
1786 going to put back. */
1787 if (array != orig_array) {
1792 /* Good. No-one added anything this time round. */
1797 /* Someone attempted to iterate or set the hash name while we had
1798 the array set to 0. We'll catch backferences on the next time
1799 round the while loop. */
1800 assert(HvARRAY(hv));
1802 if (HvAUX(hv)->xhv_name) {
1803 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1807 if (--attempts == 0) {
1808 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1812 HvARRAY(hv) = orig_array;
1814 /* If the hash was actually a symbol table, put the name back. */
1816 /* We have restored the original array. If name is non-NULL, then
1817 the original array had an aux structure at the end. So this is
1819 SvFLAGS(hv) |= SVf_OOK;
1820 HvAUX(hv)->xhv_name = name;
1825 =for apidoc hv_undef
1833 Perl_hv_undef(pTHX_ HV *hv)
1836 register XPVHV* xhv;
1841 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1842 xhv = (XPVHV*)SvANY(hv);
1844 if ((name = HvNAME_get(hv))) {
1846 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1847 hv_name_set(hv, NULL, 0, 0);
1849 SvFLAGS(hv) &= ~SVf_OOK;
1850 Safefree(HvARRAY(hv));
1851 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1853 HvPLACEHOLDERS_set(hv, 0);
1859 static struct xpvhv_aux*
1860 S_hv_auxinit(HV *hv) {
1861 struct xpvhv_aux *iter;
1865 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1866 + sizeof(struct xpvhv_aux), char);
1868 array = (char *) HvARRAY(hv);
1869 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1870 + sizeof(struct xpvhv_aux), char);
1872 HvARRAY(hv) = (HE**) array;
1873 /* SvOOK_on(hv) attacks the IV flags. */
1874 SvFLAGS(hv) |= SVf_OOK;
1877 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1878 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1880 iter->xhv_backreferences = 0;
1885 =for apidoc hv_iterinit
1887 Prepares a starting point to traverse a hash table. Returns the number of
1888 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1889 currently only meaningful for hashes without tie magic.
1891 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1892 hash buckets that happen to be in use. If you still need that esoteric
1893 value, you can get it through the macro C<HvFILL(tb)>.
1900 Perl_hv_iterinit(pTHX_ HV *hv)
1903 Perl_croak(aTHX_ "Bad hash");
1906 struct xpvhv_aux * const iter = HvAUX(hv);
1907 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1908 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1910 hv_free_ent(hv, entry);
1912 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1913 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1918 /* used to be xhv->xhv_fill before 5.004_65 */
1919 return HvTOTALKEYS(hv);
1923 Perl_hv_riter_p(pTHX_ HV *hv) {
1924 struct xpvhv_aux *iter;
1927 Perl_croak(aTHX_ "Bad hash");
1929 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1930 return &(iter->xhv_riter);
1934 Perl_hv_eiter_p(pTHX_ HV *hv) {
1935 struct xpvhv_aux *iter;
1938 Perl_croak(aTHX_ "Bad hash");
1940 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1941 return &(iter->xhv_eiter);
1945 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1946 struct xpvhv_aux *iter;
1949 Perl_croak(aTHX_ "Bad hash");
1957 iter = hv_auxinit(hv);
1959 iter->xhv_riter = riter;
1963 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1964 struct xpvhv_aux *iter;
1967 Perl_croak(aTHX_ "Bad hash");
1972 /* 0 is the default so don't go malloc()ing a new structure just to
1977 iter = hv_auxinit(hv);
1979 iter->xhv_eiter = eiter;
1983 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1986 struct xpvhv_aux *iter;
1989 PERL_UNUSED_ARG(flags);
1992 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1996 if (iter->xhv_name) {
1997 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2003 iter = hv_auxinit(hv);
2005 PERL_HASH(hash, name, len);
2006 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2010 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2011 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2012 PERL_UNUSED_CONTEXT;
2013 return &(iter->xhv_backreferences);
2017 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2023 av = HvAUX(hv)->xhv_backreferences;
2026 HvAUX(hv)->xhv_backreferences = 0;
2027 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2032 hv_iternext is implemented as a macro in hv.h
2034 =for apidoc hv_iternext
2036 Returns entries from a hash iterator. See C<hv_iterinit>.
2038 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2039 iterator currently points to, without losing your place or invalidating your
2040 iterator. Note that in this case the current entry is deleted from the hash
2041 with your iterator holding the last reference to it. Your iterator is flagged
2042 to free the entry on the next call to C<hv_iternext>, so you must not discard
2043 your iterator immediately else the entry will leak - call C<hv_iternext> to
2044 trigger the resource deallocation.
2046 =for apidoc hv_iternext_flags
2048 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2049 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2050 set the placeholders keys (for restricted hashes) will be returned in addition
2051 to normal keys. By default placeholders are automatically skipped over.
2052 Currently a placeholder is implemented with a value that is
2053 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2054 restricted hashes may change, and the implementation currently is
2055 insufficiently abstracted for any change to be tidy.
2061 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2064 register XPVHV* xhv;
2068 struct xpvhv_aux *iter;
2071 Perl_croak(aTHX_ "Bad hash");
2073 xhv = (XPVHV*)SvANY(hv);
2076 /* Too many things (well, pp_each at least) merrily assume that you can
2077 call iv_iternext without calling hv_iterinit, so we'll have to deal
2083 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2084 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2085 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2086 SV * const key = sv_newmortal();
2088 sv_setsv(key, HeSVKEY_force(entry));
2089 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2095 /* one HE per MAGICAL hash */
2096 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2098 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2100 HeKEY_hek(entry) = hek;
2101 HeKLEN(entry) = HEf_SVKEY;
2103 magic_nextpack((SV*) hv,mg,key);
2105 /* force key to stay around until next time */
2106 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2107 return entry; /* beware, hent_val is not set */
2110 SvREFCNT_dec(HeVAL(entry));
2111 Safefree(HeKEY_hek(entry));
2113 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2117 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2118 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2121 /* The prime_env_iter() on VMS just loaded up new hash values
2122 * so the iteration count needs to be reset back to the beginning
2126 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2131 /* hv_iterint now ensures this. */
2132 assert (HvARRAY(hv));
2134 /* At start of hash, entry is NULL. */
2137 entry = HeNEXT(entry);
2138 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2140 * Skip past any placeholders -- don't want to include them in
2143 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2144 entry = HeNEXT(entry);
2149 /* OK. Come to the end of the current list. Grab the next one. */
2151 iter->xhv_riter++; /* HvRITER(hv)++ */
2152 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2153 /* There is no next one. End of the hash. */
2154 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2157 entry = (HvARRAY(hv))[iter->xhv_riter];
2159 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2160 /* If we have an entry, but it's a placeholder, don't count it.
2162 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2163 entry = HeNEXT(entry);
2165 /* Will loop again if this linked list starts NULL
2166 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2167 or if we run through it and find only placeholders. */
2170 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2172 hv_free_ent(hv, oldentry);
2175 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2176 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2178 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2183 =for apidoc hv_iterkey
2185 Returns the key from the current position of the hash iterator. See
2192 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2194 if (HeKLEN(entry) == HEf_SVKEY) {
2196 char * const p = SvPV(HeKEY_sv(entry), len);
2201 *retlen = HeKLEN(entry);
2202 return HeKEY(entry);
2206 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2208 =for apidoc hv_iterkeysv
2210 Returns the key as an C<SV*> from the current position of the hash
2211 iterator. The return value will always be a mortal copy of the key. Also
2218 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2220 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2224 =for apidoc hv_iterval
2226 Returns the value from the current position of the hash iterator. See
2233 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2235 if (SvRMAGICAL(hv)) {
2236 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2237 SV* const sv = sv_newmortal();
2238 if (HeKLEN(entry) == HEf_SVKEY)
2239 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2241 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2245 return HeVAL(entry);
2249 =for apidoc hv_iternextsv
2251 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2258 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2260 HE * const he = hv_iternext_flags(hv, 0);
2264 *key = hv_iterkey(he, retlen);
2265 return hv_iterval(hv, he);
2272 =for apidoc hv_magic
2274 Adds magic to a hash. See C<sv_magic>.
2279 /* possibly free a shared string if no one has access to it
2280 * len and hash must both be valid for str.
2283 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2285 unshare_hek_or_pvn (NULL, str, len, hash);
2290 Perl_unshare_hek(pTHX_ HEK *hek)
2293 unshare_hek_or_pvn(hek, NULL, 0, 0);
2296 /* possibly free a shared string if no one has access to it
2297 hek if non-NULL takes priority over the other 3, else str, len and hash
2298 are used. If so, len and hash must both be valid for str.
2301 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2304 register XPVHV* xhv;
2306 register HE **oentry;
2308 bool is_utf8 = FALSE;
2310 const char * const save = str;
2311 struct shared_he *he = NULL;
2314 /* Find the shared he which is just before us in memory. */
2315 he = (struct shared_he *)(((char *)hek)
2316 - STRUCT_OFFSET(struct shared_he,
2319 /* Assert that the caller passed us a genuine (or at least consistent)
2321 assert (he->shared_he_he.hent_hek == hek);
2324 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2325 --he->shared_he_he.he_valu.hent_refcount;
2326 UNLOCK_STRTAB_MUTEX;
2329 UNLOCK_STRTAB_MUTEX;
2331 hash = HEK_HASH(hek);
2332 } else if (len < 0) {
2333 STRLEN tmplen = -len;
2335 /* See the note in hv_fetch(). --jhi */
2336 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2339 k_flags = HVhek_UTF8;
2341 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2344 /* what follows was the moral equivalent of:
2345 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2347 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2349 xhv = (XPVHV*)SvANY(PL_strtab);
2350 /* assert(xhv_array != 0) */
2352 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2354 const HE *const he_he = &(he->shared_he_he);
2355 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2360 const int flags_masked = k_flags & HVhek_MASK;
2361 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2362 if (HeHASH(entry) != hash) /* strings can't be equal */
2364 if (HeKLEN(entry) != len)
2366 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2368 if (HeKFLAGS(entry) != flags_masked)
2375 if (--entry->he_valu.hent_refcount == 0) {
2376 *oentry = HeNEXT(entry);
2378 /* There are now no entries in our slot. */
2379 xhv->xhv_fill--; /* HvFILL(hv)-- */
2382 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2386 UNLOCK_STRTAB_MUTEX;
2387 if (!entry && ckWARN_d(WARN_INTERNAL))
2388 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2389 "Attempt to free non-existent shared string '%s'%s"
2391 hek ? HEK_KEY(hek) : str,
2392 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2393 if (k_flags & HVhek_FREEKEY)
2397 /* get a (constant) string ptr from the global string table
2398 * string will get added if it is not already there.
2399 * len and hash must both be valid for str.
2402 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2404 bool is_utf8 = FALSE;
2406 const char * const save = str;
2409 STRLEN tmplen = -len;
2411 /* See the note in hv_fetch(). --jhi */
2412 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2414 /* If we were able to downgrade here, then than means that we were passed
2415 in a key which only had chars 0-255, but was utf8 encoded. */
2418 /* If we found we were able to downgrade the string to bytes, then
2419 we should flag that it needs upgrading on keys or each. Also flag
2420 that we need share_hek_flags to free the string. */
2422 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2425 return share_hek_flags (str, len, hash, flags);
2429 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2433 const int flags_masked = flags & HVhek_MASK;
2434 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2436 /* what follows is the moral equivalent of:
2438 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2439 hv_store(PL_strtab, str, len, NULL, hash);
2441 Can't rehash the shared string table, so not sure if it's worth
2442 counting the number of entries in the linked list
2444 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2445 /* assert(xhv_array != 0) */
2447 entry = (HvARRAY(PL_strtab))[hindex];
2448 for (;entry; entry = HeNEXT(entry)) {
2449 if (HeHASH(entry) != hash) /* strings can't be equal */
2451 if (HeKLEN(entry) != len)
2453 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2455 if (HeKFLAGS(entry) != flags_masked)
2461 /* What used to be head of the list.
2462 If this is NULL, then we're the first entry for this slot, which
2463 means we need to increate fill. */
2464 struct shared_he *new_entry;
2467 HE **const head = &HvARRAY(PL_strtab)[hindex];
2468 HE *const next = *head;
2470 /* We don't actually store a HE from the arena and a regular HEK.
2471 Instead we allocate one chunk of memory big enough for both,
2472 and put the HEK straight after the HE. This way we can find the
2473 HEK directly from the HE.
2476 Newx(k, STRUCT_OFFSET(struct shared_he,
2477 shared_he_hek.hek_key[0]) + len + 2, char);
2478 new_entry = (struct shared_he *)k;
2479 entry = &(new_entry->shared_he_he);
2480 hek = &(new_entry->shared_he_hek);
2482 Copy(str, HEK_KEY(hek), len, char);
2483 HEK_KEY(hek)[len] = 0;
2485 HEK_HASH(hek) = hash;
2486 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2488 /* Still "point" to the HEK, so that other code need not know what
2490 HeKEY_hek(entry) = hek;
2491 entry->he_valu.hent_refcount = 0;
2492 HeNEXT(entry) = next;
2495 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2496 if (!next) { /* initial entry? */
2497 xhv->xhv_fill++; /* HvFILL(hv)++ */
2498 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2503 ++entry->he_valu.hent_refcount;
2504 UNLOCK_STRTAB_MUTEX;
2506 if (flags & HVhek_FREEKEY)
2509 return HeKEY_hek(entry);
2513 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2516 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2517 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2518 if (uf->uf_set == NULL) {
2519 SV* obj = mg->mg_obj;
2520 mg->mg_obj = keysv; /* pass key */
2521 uf->uf_index = action; /* pass action */
2522 magic_getuvar((SV*)hv, mg);
2523 keysv = mg->mg_obj; /* may have changed */
2531 Perl_hv_placeholders_p(pTHX_ HV *hv)
2534 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2537 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2540 Perl_die(aTHX_ "panic: hv_placeholders_p");
2543 return &(mg->mg_len);
2548 Perl_hv_placeholders_get(pTHX_ HV *hv)
2551 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2553 return mg ? mg->mg_len : 0;
2557 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2560 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2565 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2566 Perl_die(aTHX_ "panic: hv_placeholders_set");
2568 /* else we don't need to add magic to record 0 placeholders. */
2572 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2576 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2581 value = &PL_sv_placeholder;
2584 value = (he->refcounted_he_data[0] & HVrhek_UV)
2585 ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
2586 : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
2589 /* Create a string SV that directly points to the bytes in our
2591 value = newSV_type(SVt_PV);
2592 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2593 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2594 /* This stops anything trying to free it */
2595 SvLEN_set(value, 0);
2597 SvREADONLY_on(value);
2598 if (he->refcounted_he_data[0] & HVrhek_UTF8)
2602 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2603 he->refcounted_he_data[0]);
2609 /* A big expression to find the key offset */
2610 #define REF_HE_KEY(chain) \
2611 ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
2612 ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
2613 + 1 + chain->refcounted_he_data)
2617 =for apidoc refcounted_he_chain_2hv
2619 Generates and returns a C<HV *> by walking up the tree starting at the passed
2620 in C<struct refcounted_he *>.
2625 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2629 U32 placeholders = 0;
2630 /* We could chase the chain once to get an idea of the number of keys,
2631 and call ksplit. But for now we'll make a potentially inefficient
2632 hash with only 8 entries in its array. */
2633 const U32 max = HvMAX(hv);
2637 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2638 HvARRAY(hv) = (HE**)array;
2643 U32 hash = chain->refcounted_he_hash;
2645 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2647 HE **oentry = &((HvARRAY(hv))[hash & max]);
2648 HE *entry = *oentry;
2651 for (; entry; entry = HeNEXT(entry)) {
2652 if (HeHASH(entry) == hash) {
2653 /* We might have a duplicate key here. If so, entry is older
2654 than the key we've already put in the hash, so if they are
2655 the same, skip adding entry. */
2657 const STRLEN klen = HeKLEN(entry);
2658 const char *const key = HeKEY(entry);
2659 if (klen == chain->refcounted_he_keylen
2660 && (!!HeKUTF8(entry)
2661 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2662 && memEQ(key, REF_HE_KEY(chain), klen))
2665 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2667 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2668 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2669 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2680 = share_hek_flags(REF_HE_KEY(chain),
2681 chain->refcounted_he_keylen,
2682 chain->refcounted_he_hash,
2683 (chain->refcounted_he_data[0]
2684 & (HVhek_UTF8|HVhek_WASUTF8)));
2686 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2688 value = refcounted_he_value(chain);
2689 if (value == &PL_sv_placeholder)
2691 HeVAL(entry) = value;
2693 /* Link it into the chain. */
2694 HeNEXT(entry) = *oentry;
2695 if (!HeNEXT(entry)) {
2696 /* initial entry. */
2704 chain = chain->refcounted_he_next;
2708 clear_placeholders(hv, placeholders);
2709 HvTOTALKEYS(hv) -= placeholders;
2712 /* We could check in the loop to see if we encounter any keys with key
2713 flags, but it's probably not worth it, as this per-hash flag is only
2714 really meant as an optimisation for things like Storable. */
2716 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2722 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2723 const char *key, STRLEN klen, int flags, U32 hash)
2726 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2727 of your key has to exactly match that which is stored. */
2728 SV *value = &PL_sv_placeholder;
2732 if (flags & HVhek_FREEKEY)
2734 key = SvPV_const(keysv, klen);
2736 is_utf8 = (SvUTF8(keysv) != 0);
2738 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2742 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2743 hash = SvSHARED_HASH(keysv);
2745 PERL_HASH(hash, key, klen);
2749 for (; chain; chain = chain->refcounted_he_next) {
2751 if (hash != chain->refcounted_he_hash)
2753 if (klen != chain->refcounted_he_keylen)
2755 if (memNE(REF_HE_KEY(chain),key,klen))
2757 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2760 if (hash != HEK_HASH(chain->refcounted_he_hek))
2762 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2764 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2766 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2770 value = sv_2mortal(refcounted_he_value(chain));
2774 if (flags & HVhek_FREEKEY)
2781 =for apidoc refcounted_he_new
2783 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2784 stored in a compact form, all references remain the property of the caller.
2785 The C<struct refcounted_he> is returned with a reference count of 1.
2790 struct refcounted_he *
2791 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2792 SV *const key, SV *const value) {
2794 struct refcounted_he *he;
2796 const char *key_p = SvPV_const(key, key_len);
2797 STRLEN value_len = 0;
2798 const char *value_p = NULL;
2803 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2806 value_type = HVrhek_PV;
2807 } else if (SvIOK(value)) {
2808 value_type = HVrhek_IV;
2809 } else if (value == &PL_sv_placeholder) {
2810 value_type = HVrhek_delete;
2811 } else if (!SvOK(value)) {
2812 value_type = HVrhek_undef;
2814 value_type = HVrhek_PV;
2817 if (value_type == HVrhek_PV) {
2818 value_p = SvPV_const(value, value_len);
2819 key_offset = value_len + 2;
2827 he = (struct refcounted_he*)
2828 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2832 he = (struct refcounted_he*)
2833 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2838 he->refcounted_he_next = parent;
2840 if (value_type == HVrhek_PV) {
2841 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2842 he->refcounted_he_val.refcounted_he_u_len = value_len;
2843 if (SvUTF8(value)) {
2844 flags |= HVrhek_UTF8;
2846 } else if (value_type == HVrhek_IV) {
2848 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2851 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2856 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2857 As we're going to be building hash keys from this value in future,
2858 normalise it now. */
2859 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2860 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2862 PERL_HASH(hash, key_p, key_len);
2865 he->refcounted_he_hash = hash;
2866 he->refcounted_he_keylen = key_len;
2867 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2869 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2872 if (flags & HVhek_WASUTF8) {
2873 /* If it was downgraded from UTF-8, then the pointer returned from
2874 bytes_from_utf8 is an allocated pointer that we must free. */
2878 he->refcounted_he_data[0] = flags;
2879 he->refcounted_he_refcnt = 1;
2885 =for apidoc refcounted_he_free
2887 Decrements the reference count of the passed in C<struct refcounted_he *>
2888 by one. If the reference count reaches zero the structure's memory is freed,
2889 and C<refcounted_he_free> iterates onto the parent node.
2895 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2897 PERL_UNUSED_CONTEXT;
2900 struct refcounted_he *copy;
2904 new_count = --he->refcounted_he_refcnt;
2905 HINTS_REFCNT_UNLOCK;
2911 #ifndef USE_ITHREADS
2912 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2915 he = he->refcounted_he_next;
2916 PerlMemShared_free(copy);
2921 =for apidoc hv_assert
2923 Check that a hash is in an internally consistent state.
2931 Perl_hv_assert(pTHX_ HV *hv)
2936 int placeholders = 0;
2939 const I32 riter = HvRITER_get(hv);
2940 HE *eiter = HvEITER_get(hv);
2942 (void)hv_iterinit(hv);
2944 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2945 /* sanity check the values */
2946 if (HeVAL(entry) == &PL_sv_placeholder)
2950 /* sanity check the keys */
2951 if (HeSVKEY(entry)) {
2952 NOOP; /* Don't know what to check on SV keys. */
2953 } else if (HeKUTF8(entry)) {
2955 if (HeKWASUTF8(entry)) {
2956 PerlIO_printf(Perl_debug_log,
2957 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2958 (int) HeKLEN(entry), HeKEY(entry));
2961 } else if (HeKWASUTF8(entry))
2964 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2965 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2966 const int nhashkeys = HvUSEDKEYS(hv);
2967 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2969 if (nhashkeys != real) {
2970 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2973 if (nhashplaceholders != placeholders) {
2974 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2978 if (withflags && ! HvHASKFLAGS(hv)) {
2979 PerlIO_printf(Perl_debug_log,
2980 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2987 HvRITER_set(hv, riter); /* Restore hash iterator state */
2988 HvEITER_set(hv, eiter);
2995 * c-indentation-style: bsd
2997 * indent-tabs-mode: t
3000 * ex: set ts=8 sts=4 sw=4 noet: