3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 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
41 New(54, he, PERL_ARENA_SIZE/sizeof(HE), HE);
42 HeNEXT(he) = PL_he_arenaroot;
45 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
48 HeNEXT(he) = (HE*)(he + 1);
62 PL_he_root = HeNEXT(he);
71 HeNEXT(p) = (HE*)PL_he_root;
78 #define new_HE() (HE*)safemalloc(sizeof(HE))
79 #define del_HE(p) safefree((char*)p)
83 #define new_HE() new_he()
84 #define del_HE(p) del_he(p)
89 S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
91 const int flags_masked = flags & HVhek_MASK;
95 New(54, k, HEK_BASESIZE + len + 2, char);
97 Copy(str, HEK_KEY(hek), len, char);
98 HEK_KEY(hek)[len] = 0;
100 HEK_HASH(hek) = hash;
101 HEK_FLAGS(hek) = (unsigned char)flags_masked;
103 if (flags & HVhek_FREEKEY)
108 /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
112 Perl_free_tied_hv_pool(pTHX)
115 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
122 PL_hv_fetch_ent_mh = Nullhe;
125 #if defined(USE_ITHREADS)
127 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
133 /* look for it in the table first */
134 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
138 /* create anew and remember what it is */
140 ptr_table_store(PL_ptr_table, e, ret);
142 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
143 if (HeKLEN(e) == HEf_SVKEY) {
145 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
146 HeKEY_hek(ret) = (HEK*)k;
147 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
150 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
153 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
155 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
158 #endif /* USE_ITHREADS */
161 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
164 SV *sv = sv_newmortal();
165 if (!(flags & HVhek_FREEKEY)) {
166 sv_setpvn(sv, key, klen);
169 /* Need to free saved eventually assign to mortal SV */
170 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
171 sv_usepvn(sv, (char *) key, klen);
173 if (flags & HVhek_UTF8) {
176 Perl_croak(aTHX_ msg, sv);
179 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
182 #define HV_FETCH_ISSTORE 0x01
183 #define HV_FETCH_ISEXISTS 0x02
184 #define HV_FETCH_LVALUE 0x04
185 #define HV_FETCH_JUST_SV 0x08
190 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
191 the length of the key. The C<hash> parameter is the precomputed hash
192 value; if it is zero then Perl will compute it. The return value will be
193 NULL if the operation failed or if the value did not need to be actually
194 stored within the hash (as in the case of tied hashes). Otherwise it can
195 be dereferenced to get the original C<SV*>. Note that the caller is
196 responsible for suitably incrementing the reference count of C<val> before
197 the call, and decrementing it if the function returned NULL. Effectively
198 a successful hv_store takes ownership of one reference to C<val>. This is
199 usually what you want; a newly created SV has a reference count of one, so
200 if all your code does is create SVs then store them in a hash, hv_store
201 will own the only reference to the new SV, and your code doesn't need to do
202 anything further to tidy up. hv_store is not implemented as a call to
203 hv_store_ent, and does not create a temporary SV for the key, so if your
204 key data is not already in SV form then use hv_store in preference to
207 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
208 information on how to use this function on tied hashes.
214 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
227 hek = hv_fetch_common (hv, NULL, key, klen, flags,
228 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
229 return hek ? &HeVAL(hek) : NULL;
233 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
234 register U32 hash, int flags)
236 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
237 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
238 return hek ? &HeVAL(hek) : NULL;
242 =for apidoc hv_store_ent
244 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
245 parameter is the precomputed hash value; if it is zero then Perl will
246 compute it. The return value is the new hash entry so created. It will be
247 NULL if the operation failed or if the value did not need to be actually
248 stored within the hash (as in the case of tied hashes). Otherwise the
249 contents of the return value can be accessed using the C<He?> macros
250 described here. Note that the caller is responsible for suitably
251 incrementing the reference count of C<val> before the call, and
252 decrementing it if the function returned NULL. Effectively a successful
253 hv_store_ent takes ownership of one reference to C<val>. This is
254 usually what you want; a newly created SV has a reference count of one, so
255 if all your code does is create SVs then store them in a hash, hv_store
256 will own the only reference to the new SV, and your code doesn't need to do
257 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
258 unlike C<val> it does not take ownership of it, so maintaining the correct
259 reference count on C<key> is entirely the caller's responsibility. hv_store
260 is not implemented as a call to hv_store_ent, and does not create a temporary
261 SV for the key, so if your key data is not already in SV form then use
262 hv_store in preference to hv_store_ent.
264 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
265 information on how to use this function on tied hashes.
271 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
273 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
277 =for apidoc hv_exists
279 Returns a boolean indicating whether the specified hash key exists. The
280 C<klen> is the length of the key.
286 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
298 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
305 Returns the SV which corresponds to the specified key in the hash. The
306 C<klen> is the length of the key. If C<lval> is set then the fetch will be
307 part of a store. Check that the return value is non-null before
308 dereferencing it to an C<SV*>.
310 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
311 information on how to use this function on tied hashes.
317 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
330 hek = hv_fetch_common (hv, NULL, key, klen, flags,
331 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
333 return hek ? &HeVAL(hek) : NULL;
337 =for apidoc hv_exists_ent
339 Returns a boolean indicating whether the specified hash key exists. C<hash>
340 can be a valid precomputed hash value, or 0 to ask for it to be
347 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
349 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
353 /* returns an HE * structure with the all fields set */
354 /* note that hent_val will be a mortal sv for MAGICAL hashes */
356 =for apidoc hv_fetch_ent
358 Returns the hash entry which corresponds to the specified key in the hash.
359 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
360 if you want the function to compute it. IF C<lval> is set then the fetch
361 will be part of a store. Make sure the return value is non-null before
362 accessing it. The return value when C<tb> is a tied hash is a pointer to a
363 static location, so be sure to make a copy of the structure if you need to
366 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
367 information on how to use this function on tied hashes.
373 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
375 return hv_fetch_common(hv, keysv, NULL, 0, 0,
376 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
380 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
381 int flags, int action, SV *val, register U32 hash)
396 if (flags & HVhek_FREEKEY)
398 key = SvPV(keysv, klen);
400 is_utf8 = (SvUTF8(keysv) != 0);
402 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
405 xhv = (XPVHV*)SvANY(hv);
407 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
409 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
412 /* XXX should be able to skimp on the HE/HEK here when
413 HV_FETCH_JUST_SV is true. */
416 keysv = newSVpvn(key, klen);
421 keysv = newSVsv(keysv);
423 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
425 /* grab a fake HE/HEK pair from the pool or make a new one */
426 entry = PL_hv_fetch_ent_mh;
428 PL_hv_fetch_ent_mh = HeNEXT(entry);
432 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
433 HeKEY_hek(entry) = (HEK*)k;
435 HeNEXT(entry) = Nullhe;
436 HeSVKEY_set(entry, keysv);
438 sv_upgrade(sv, SVt_PVLV);
440 /* so we can free entry when freeing sv */
441 LvTARG(sv) = (SV*)entry;
443 /* XXX remove at some point? */
444 if (flags & HVhek_FREEKEY)
449 #ifdef ENV_IS_CASELESS
450 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
452 for (i = 0; i < klen; ++i)
453 if (isLOWER(key[i])) {
454 /* Would be nice if we had a routine to do the
455 copy and upercase in a single pass through. */
456 const char *nkey = strupr(savepvn(key,klen));
457 /* Note that this fetch is for nkey (the uppercased
458 key) whereas the store is for key (the original) */
459 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
460 HVhek_FREEKEY, /* free nkey */
461 0 /* non-LVAL fetch */,
462 Nullsv /* no value */,
463 0 /* compute hash */);
464 if (!entry && (action & HV_FETCH_LVALUE)) {
465 /* This call will free key if necessary.
466 Do it this way to encourage compiler to tail
468 entry = hv_fetch_common(hv, keysv, key, klen,
469 flags, HV_FETCH_ISSTORE,
472 if (flags & HVhek_FREEKEY)
480 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
481 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
483 /* I don't understand why hv_exists_ent has svret and sv,
484 whereas hv_exists only had one. */
485 svret = sv_newmortal();
488 if (keysv || is_utf8) {
490 keysv = newSVpvn(key, klen);
493 keysv = newSVsv(keysv);
495 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
497 mg_copy((SV*)hv, sv, key, klen);
499 if (flags & HVhek_FREEKEY)
501 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
502 /* This cast somewhat evil, but I'm merely using NULL/
503 not NULL to return the boolean exists.
504 And I know hv is not NULL. */
505 return SvTRUE(svret) ? (HE *)hv : NULL;
507 #ifdef ENV_IS_CASELESS
508 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
509 /* XXX This code isn't UTF8 clean. */
510 const char *keysave = key;
511 /* Will need to free this, so set FREEKEY flag. */
512 key = savepvn(key,klen);
513 key = (const char*)strupr((char*)key);
518 if (flags & HVhek_FREEKEY) {
521 flags |= HVhek_FREEKEY;
525 else if (action & HV_FETCH_ISSTORE) {
528 hv_magic_check (hv, &needs_copy, &needs_store);
530 const bool save_taint = PL_tainted;
531 if (keysv || is_utf8) {
533 keysv = newSVpvn(key, klen);
537 PL_tainted = SvTAINTED(keysv);
538 keysv = sv_2mortal(newSVsv(keysv));
539 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
541 mg_copy((SV*)hv, val, key, klen);
544 TAINT_IF(save_taint);
545 if (!HvARRAY(hv) && !needs_store) {
546 if (flags & HVhek_FREEKEY)
550 #ifdef ENV_IS_CASELESS
551 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
552 /* XXX This code isn't UTF8 clean. */
553 const char *keysave = key;
554 /* Will need to free this, so set FREEKEY flag. */
555 key = savepvn(key,klen);
556 key = (const char*)strupr((char*)key);
561 if (flags & HVhek_FREEKEY) {
564 flags |= HVhek_FREEKEY;
572 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
573 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
574 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
577 Newz(503, HvARRAY(hv),
578 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
580 #ifdef DYNAMIC_ENV_FETCH
581 else if (action & HV_FETCH_ISEXISTS) {
582 /* for an %ENV exists, if we do an insert it's by a recursive
583 store call, so avoid creating HvARRAY(hv) right now. */
587 /* XXX remove at some point? */
588 if (flags & HVhek_FREEKEY)
596 const char *keysave = key;
597 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
601 flags &= ~HVhek_UTF8;
602 if (key != keysave) {
603 if (flags & HVhek_FREEKEY)
605 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
610 PERL_HASH_INTERNAL(hash, key, klen);
611 /* We don't have a pointer to the hv, so we have to replicate the
612 flag into every HEK, so that hv_iterkeysv can see it. */
613 /* And yes, you do need this even though you are not "storing" because
614 you can flip the flags below if doing an lval lookup. (And that
615 was put in to give the semantics Andreas was expecting.) */
616 flags |= HVhek_REHASH;
618 if (keysv && (SvIsCOW_shared_hash(keysv))) {
621 PERL_HASH(hash, key, klen);
625 masked_flags = (flags & HVhek_MASK);
628 #ifdef DYNAMIC_ENV_FETCH
629 if (!HvARRAY(hv)) entry = Null(HE*);
633 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
635 for (; entry; ++n_links, entry = HeNEXT(entry)) {
636 if (HeHASH(entry) != hash) /* strings can't be equal */
638 if (HeKLEN(entry) != (I32)klen)
640 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
642 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
645 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
646 if (HeKFLAGS(entry) != masked_flags) {
647 /* We match if HVhek_UTF8 bit in our flags and hash key's
648 match. But if entry was set previously with HVhek_WASUTF8
649 and key now doesn't (or vice versa) then we should change
650 the key's flag, as this is assignment. */
651 if (HvSHAREKEYS(hv)) {
652 /* Need to swap the key we have for a key with the flags we
653 need. As keys are shared we can't just write to the
654 flag, so we share the new one, unshare the old one. */
655 HEK *new_hek = share_hek_flags(key, klen, hash,
657 unshare_hek (HeKEY_hek(entry));
658 HeKEY_hek(entry) = new_hek;
661 HeKFLAGS(entry) = masked_flags;
662 if (masked_flags & HVhek_ENABLEHVKFLAGS)
665 if (HeVAL(entry) == &PL_sv_placeholder) {
666 /* yes, can store into placeholder slot */
667 if (action & HV_FETCH_LVALUE) {
669 /* This preserves behaviour with the old hv_fetch
670 implementation which at this point would bail out
671 with a break; (at "if we find a placeholder, we
672 pretend we haven't found anything")
674 That break mean that if a placeholder were found, it
675 caused a call into hv_store, which in turn would
676 check magic, and if there is no magic end up pretty
677 much back at this point (in hv_store's code). */
680 /* LVAL fetch which actaully needs a store. */
682 HvPLACEHOLDERS(hv)--;
685 if (val != &PL_sv_placeholder)
686 HvPLACEHOLDERS(hv)--;
689 } else if (action & HV_FETCH_ISSTORE) {
690 SvREFCNT_dec(HeVAL(entry));
693 } else if (HeVAL(entry) == &PL_sv_placeholder) {
694 /* if we find a placeholder, we pretend we haven't found
698 if (flags & HVhek_FREEKEY)
702 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
703 if (!(action & HV_FETCH_ISSTORE)
704 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
706 char *env = PerlEnv_ENVgetenv_len(key,&len);
708 sv = newSVpvn(env,len);
710 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
716 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
717 S_hv_notallowed(aTHX_ flags, key, klen,
718 "Attempt to access disallowed key '%"SVf"' in"
719 " a restricted hash");
721 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
722 /* Not doing some form of store, so return failure. */
723 if (flags & HVhek_FREEKEY)
727 if (action & HV_FETCH_LVALUE) {
730 /* At this point the old hv_fetch code would call to hv_store,
731 which in turn might do some tied magic. So we need to make that
732 magic check happen. */
733 /* gonna assign to this, so it better be there */
734 return hv_fetch_common(hv, keysv, key, klen, flags,
735 HV_FETCH_ISSTORE, val, hash);
736 /* XXX Surely that could leak if the fetch-was-store fails?
737 Just like the hv_fetch. */
741 /* Welcome to hv_store... */
744 /* Not sure if we can get here. I think the only case of oentry being
745 NULL is for %ENV with dynamic env fetch. But that should disappear
746 with magic in the previous code. */
747 Newz(503, HvARRAY(hv),
748 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
752 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
755 /* share_hek_flags will do the free for us. This might be considered
758 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
759 else /* gotta do the real thing */
760 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
762 HeNEXT(entry) = *oentry;
765 if (val == &PL_sv_placeholder)
766 HvPLACEHOLDERS(hv)++;
767 if (masked_flags & HVhek_ENABLEHVKFLAGS)
770 xhv->xhv_keys++; /* HvKEYS(hv)++ */
771 if (!n_links) { /* initial entry? */
772 xhv->xhv_fill++; /* HvFILL(hv)++ */
773 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
774 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
775 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
776 splits on a rehashed hash, as we're not going to split it again,
777 and if someone is lucky (evil) enough to get all the keys in one
778 list they could exhaust our memory as we repeatedly double the
779 number of buckets on every entry. Linear search feels a less worse
788 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
790 const MAGIC *mg = SvMAGIC(hv);
794 if (isUPPER(mg->mg_type)) {
796 switch (mg->mg_type) {
797 case PERL_MAGIC_tied:
799 *needs_store = FALSE;
802 mg = mg->mg_moremagic;
807 =for apidoc hv_scalar
809 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
815 Perl_hv_scalar(pTHX_ HV *hv)
820 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
821 sv = magic_scalarpack(hv, mg);
827 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
828 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
836 =for apidoc hv_delete
838 Deletes a key/value pair in the hash. The value SV is removed from the
839 hash and returned to the caller. The C<klen> is the length of the key.
840 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
847 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
854 k_flags |= HVhek_UTF8;
858 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
862 =for apidoc hv_delete_ent
864 Deletes a key/value pair in the hash. The value SV is removed from the
865 hash and returned to the caller. The C<flags> value will normally be zero;
866 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
867 precomputed hash value, or 0 to ask for it to be computed.
873 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
875 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
879 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
880 int k_flags, I32 d_flags, U32 hash)
886 register HE **oentry;
895 if (k_flags & HVhek_FREEKEY)
897 key = SvPV(keysv, klen);
899 is_utf8 = (SvUTF8(keysv) != 0);
901 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
904 if (SvRMAGICAL(hv)) {
907 hv_magic_check (hv, &needs_copy, &needs_store);
910 entry = hv_fetch_common(hv, keysv, key, klen,
911 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
913 sv = entry ? HeVAL(entry) : NULL;
919 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
920 /* No longer an element */
921 sv_unmagic(sv, PERL_MAGIC_tiedelem);
924 return Nullsv; /* element cannot be deleted */
926 #ifdef ENV_IS_CASELESS
927 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
928 /* XXX This code isn't UTF8 clean. */
929 keysv = sv_2mortal(newSVpvn(key,klen));
930 if (k_flags & HVhek_FREEKEY) {
933 key = strupr(SvPVX(keysv));
942 xhv = (XPVHV*)SvANY(hv);
947 const char *keysave = key;
948 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
951 k_flags |= HVhek_UTF8;
953 k_flags &= ~HVhek_UTF8;
954 if (key != keysave) {
955 if (k_flags & HVhek_FREEKEY) {
956 /* This shouldn't happen if our caller does what we expect,
957 but strictly the API allows it. */
960 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
962 HvHASKFLAGS_on((SV*)hv);
966 PERL_HASH_INTERNAL(hash, key, klen);
968 if (keysv && (SvIsCOW_shared_hash(keysv))) {
971 PERL_HASH(hash, key, klen);
975 masked_flags = (k_flags & HVhek_MASK);
977 oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
980 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
981 if (HeHASH(entry) != hash) /* strings can't be equal */
983 if (HeKLEN(entry) != (I32)klen)
985 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
987 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
990 /* if placeholder is here, it's already been deleted.... */
991 if (HeVAL(entry) == &PL_sv_placeholder)
993 if (k_flags & HVhek_FREEKEY)
997 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
998 S_hv_notallowed(aTHX_ k_flags, key, klen,
999 "Attempt to delete readonly key '%"SVf"' from"
1000 " a restricted hash");
1002 if (k_flags & HVhek_FREEKEY)
1005 if (d_flags & G_DISCARD)
1008 sv = sv_2mortal(HeVAL(entry));
1009 HeVAL(entry) = &PL_sv_placeholder;
1013 * If a restricted hash, rather than really deleting the entry, put
1014 * a placeholder there. This marks the key as being "approved", so
1015 * we can still access via not-really-existing key without raising
1018 if (SvREADONLY(hv)) {
1019 SvREFCNT_dec(HeVAL(entry));
1020 HeVAL(entry) = &PL_sv_placeholder;
1021 /* We'll be saving this slot, so the number of allocated keys
1022 * doesn't go down, but the number placeholders goes up */
1023 HvPLACEHOLDERS(hv)++;
1025 *oentry = HeNEXT(entry);
1027 xhv->xhv_fill--; /* HvFILL(hv)-- */
1028 if (xhv->xhv_aux && entry
1029 == ((struct xpvhv_aux *)xhv->xhv_aux)->xhv_eiter /* HvEITER(hv) */)
1032 hv_free_ent(hv, entry);
1033 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1034 if (xhv->xhv_keys == 0)
1035 HvHASKFLAGS_off(hv);
1039 if (SvREADONLY(hv)) {
1040 S_hv_notallowed(aTHX_ k_flags, key, klen,
1041 "Attempt to delete disallowed key '%"SVf"' from"
1042 " a restricted hash");
1045 if (k_flags & HVhek_FREEKEY)
1051 S_hsplit(pTHX_ HV *hv)
1053 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1054 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1055 register I32 newsize = oldsize * 2;
1057 char *a = (char*) HvARRAY(hv);
1059 register HE **oentry;
1060 int longest_chain = 0;
1063 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1064 hv, (int) oldsize);*/
1066 if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) {
1067 /* Can make this clear any placeholders first for non-restricted hashes,
1068 even though Storable rebuilds restricted hashes by putting in all the
1069 placeholders (first) before turning on the readonly flag, because
1070 Storable always pre-splits the hash. */
1071 hv_clear_placeholders(hv);
1075 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1076 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1082 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1087 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1088 if (oldsize >= 64) {
1089 offer_nice_chunk(HvARRAY(hv),
1090 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1093 Safefree(HvARRAY(hv));
1097 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1098 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1099 HvARRAY(hv) = (HE**) a;
1102 for (i=0; i<oldsize; i++,aep++) {
1103 int left_length = 0;
1104 int right_length = 0;
1108 if (!*aep) /* non-existent */
1111 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1112 if ((HeHASH(entry) & newsize) != (U32)i) {
1113 *oentry = HeNEXT(entry);
1114 HeNEXT(entry) = *bep;
1116 xhv->xhv_fill++; /* HvFILL(hv)++ */
1122 oentry = &HeNEXT(entry);
1126 if (!*aep) /* everything moved */
1127 xhv->xhv_fill--; /* HvFILL(hv)-- */
1128 /* I think we don't actually need to keep track of the longest length,
1129 merely flag if anything is too long. But for the moment while
1130 developing this code I'll track it. */
1131 if (left_length > longest_chain)
1132 longest_chain = left_length;
1133 if (right_length > longest_chain)
1134 longest_chain = right_length;
1138 /* Pick your policy for "hashing isn't working" here: */
1139 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1144 if (hv == PL_strtab) {
1145 /* Urg. Someone is doing something nasty to the string table.
1150 /* Awooga. Awooga. Pathological data. */
1151 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1152 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1155 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1156 was_shared = HvSHAREKEYS(hv);
1159 HvSHAREKEYS_off(hv);
1164 for (i=0; i<newsize; i++,aep++) {
1165 register HE *entry = *aep;
1167 /* We're going to trash this HE's next pointer when we chain it
1168 into the new hash below, so store where we go next. */
1169 HE *next = HeNEXT(entry);
1174 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1179 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1180 hash, HeKFLAGS(entry));
1181 unshare_hek (HeKEY_hek(entry));
1182 HeKEY_hek(entry) = new_hek;
1184 /* Not shared, so simply write the new hash in. */
1185 HeHASH(entry) = hash;
1187 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1188 HEK_REHASH_on(HeKEY_hek(entry));
1189 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1191 /* Copy oentry to the correct new chain. */
1192 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1194 xhv->xhv_fill++; /* HvFILL(hv)++ */
1195 HeNEXT(entry) = *bep;
1201 Safefree (HvARRAY(hv));
1202 HvARRAY(hv) = (HE **)a;
1206 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1208 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1209 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1210 register I32 newsize;
1215 register HE **oentry;
1217 newsize = (I32) newmax; /* possible truncation here */
1218 if (newsize != newmax || newmax <= oldsize)
1220 while ((newsize & (1 + ~newsize)) != newsize) {
1221 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1223 if (newsize < newmax)
1225 if (newsize < newmax)
1226 return; /* overflow detection */
1228 a = (char *) HvARRAY(hv);
1231 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1232 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1238 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1243 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1244 if (oldsize >= 64) {
1245 offer_nice_chunk(HvARRAY(hv),
1246 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1249 Safefree(HvARRAY(hv));
1252 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1255 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1257 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1258 HvARRAY(hv) = (HE **) a;
1259 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1263 for (i=0; i<oldsize; i++,aep++) {
1264 if (!*aep) /* non-existent */
1266 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1268 if ((j = (HeHASH(entry) & newsize)) != i) {
1270 *oentry = HeNEXT(entry);
1271 if (!(HeNEXT(entry) = aep[j]))
1272 xhv->xhv_fill++; /* HvFILL(hv)++ */
1277 oentry = &HeNEXT(entry);
1279 if (!*aep) /* everything moved */
1280 xhv->xhv_fill--; /* HvFILL(hv)-- */
1287 Creates a new HV. The reference count is set to 1.
1296 register XPVHV* xhv;
1298 hv = (HV*)NEWSV(502,0);
1299 sv_upgrade((SV *)hv, SVt_PVHV);
1300 xhv = (XPVHV*)SvANY(hv);
1303 #ifndef NODEFAULT_SHAREKEYS
1304 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1307 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1308 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1314 Perl_newHVhv(pTHX_ HV *ohv)
1317 STRLEN hv_max, hv_fill;
1319 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1321 hv_max = HvMAX(ohv);
1323 if (!SvMAGICAL((SV *)ohv)) {
1324 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1326 const bool shared = !!HvSHAREKEYS(ohv);
1327 HE **ents, **oents = (HE **)HvARRAY(ohv);
1329 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1332 /* In each bucket... */
1333 for (i = 0; i <= hv_max; i++) {
1334 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1341 /* Copy the linked list of entries. */
1342 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1343 const U32 hash = HeHASH(oent);
1344 const char * const key = HeKEY(oent);
1345 const STRLEN len = HeKLEN(oent);
1346 const int flags = HeKFLAGS(oent);
1349 HeVAL(ent) = newSVsv(HeVAL(oent));
1351 = shared ? share_hek_flags(key, len, hash, flags)
1352 : save_hek_flags(key, len, hash, flags);
1363 HvFILL(hv) = hv_fill;
1364 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1368 /* Iterate over ohv, copying keys and values one at a time. */
1370 const I32 riter = HvRITER_get(ohv);
1371 HE * const eiter = HvEITER_get(ohv);
1373 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1374 while (hv_max && hv_max + 1 >= hv_fill * 2)
1375 hv_max = hv_max / 2;
1379 while ((entry = hv_iternext_flags(ohv, 0))) {
1380 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1381 newSVsv(HeVAL(entry)), HeHASH(entry),
1384 HvRITER_set(ohv, riter);
1385 HvEITER_set(ohv, eiter);
1392 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1399 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1400 PL_sub_generation++; /* may be deletion of method from stash */
1402 if (HeKLEN(entry) == HEf_SVKEY) {
1403 SvREFCNT_dec(HeKEY_sv(entry));
1404 Safefree(HeKEY_hek(entry));
1406 else if (HvSHAREKEYS(hv))
1407 unshare_hek(HeKEY_hek(entry));
1409 Safefree(HeKEY_hek(entry));
1414 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1418 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME_get(hv))
1419 PL_sub_generation++; /* may be deletion of method from stash */
1420 sv_2mortal(HeVAL(entry)); /* free between statements */
1421 if (HeKLEN(entry) == HEf_SVKEY) {
1422 sv_2mortal(HeKEY_sv(entry));
1423 Safefree(HeKEY_hek(entry));
1425 else if (HvSHAREKEYS(hv))
1426 unshare_hek(HeKEY_hek(entry));
1428 Safefree(HeKEY_hek(entry));
1433 =for apidoc hv_clear
1435 Clears a hash, making it empty.
1441 Perl_hv_clear(pTHX_ HV *hv)
1444 register XPVHV* xhv;
1448 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1450 xhv = (XPVHV*)SvANY(hv);
1452 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1453 /* restricted hash: convert all keys to placeholders */
1455 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1456 HE *entry = (HvARRAY(hv))[i];
1457 for (; entry; entry = HeNEXT(entry)) {
1458 /* not already placeholder */
1459 if (HeVAL(entry) != &PL_sv_placeholder) {
1460 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1461 SV* keysv = hv_iterkeysv(entry);
1463 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1466 SvREFCNT_dec(HeVAL(entry));
1467 HeVAL(entry) = &PL_sv_placeholder;
1468 HvPLACEHOLDERS(hv)++;
1476 HvPLACEHOLDERS_set(hv, 0);
1478 (void)memzero(HvARRAY(hv),
1479 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1484 HvHASKFLAGS_off(hv);
1488 HvEITER_set(hv, NULL);
1493 =for apidoc hv_clear_placeholders
1495 Clears any placeholders from a hash. If a restricted hash has any of its keys
1496 marked as readonly and the key is subsequently deleted, the key is not actually
1497 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1498 it so it will be ignored by future operations such as iterating over the hash,
1499 but will still allow the hash to have a value reassigned to the key at some
1500 future point. This function clears any such placeholder keys from the hash.
1501 See Hash::Util::lock_keys() for an example of its use.
1507 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1510 I32 items = (I32)HvPLACEHOLDERS(hv);
1517 /* Loop down the linked list heads */
1519 HE **oentry = &(HvARRAY(hv))[i];
1520 HE *entry = *oentry;
1525 for (; entry; entry = *oentry) {
1526 if (HeVAL(entry) == &PL_sv_placeholder) {
1527 *oentry = HeNEXT(entry);
1528 if (first && !*oentry)
1529 HvFILL(hv)--; /* This linked list is now empty. */
1530 if (HvEITER_get(hv))
1533 hv_free_ent(hv, entry);
1537 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS(hv);
1538 if (HvKEYS(hv) == 0)
1539 HvHASKFLAGS_off(hv);
1540 HvPLACEHOLDERS(hv) = 0;
1544 oentry = &HeNEXT(entry);
1549 /* You can't get here, hence assertion should always fail. */
1550 assert (items == 0);
1555 S_hfreeentries(pTHX_ HV *hv)
1557 register HE **array;
1561 struct xpvhv_aux *iter;
1570 array = HvARRAY(hv);
1571 /* make everyone else think the array is empty, so that the destructors
1572 * called for freed entries can't recusively mess with us */
1573 HvARRAY(hv) = Null(HE**);
1575 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1580 register HE *oentry = entry;
1581 entry = HeNEXT(entry);
1582 hv_free_ent(hv, oentry);
1587 entry = array[riter];
1590 HvARRAY(hv) = array;
1592 iter = ((XPVHV*) SvANY(hv))->xhv_aux;
1594 entry = iter->xhv_eiter; /* HvEITER(hv) */
1595 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1597 hv_free_ent(hv, entry);
1600 ((XPVHV*) SvANY(hv))->xhv_aux = 0;
1605 =for apidoc hv_undef
1613 Perl_hv_undef(pTHX_ HV *hv)
1615 register XPVHV* xhv;
1619 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1620 xhv = (XPVHV*)SvANY(hv);
1622 Safefree(HvARRAY(hv));
1623 if ((name = HvNAME_get(hv))) {
1624 /* FIXME - strlen HvNAME */
1626 hv_delete(PL_stashcache, name, strlen(name), G_DISCARD);
1627 Perl_hv_name_set(aTHX_ hv, 0, 0, 0);
1629 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1631 HvPLACEHOLDERS_set(hv, 0);
1638 S_hv_auxinit(aTHX) {
1639 struct xpvhv_aux *iter;
1641 New(0, iter, 1, struct xpvhv_aux);
1643 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1644 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1651 =for apidoc hv_iterinit
1653 Prepares a starting point to traverse a hash table. Returns the number of
1654 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1655 currently only meaningful for hashes without tie magic.
1657 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1658 hash buckets that happen to be in use. If you still need that esoteric
1659 value, you can get it through the macro C<HvFILL(tb)>.
1666 Perl_hv_iterinit(pTHX_ HV *hv)
1668 register XPVHV* xhv;
1670 struct xpvhv_aux *iter;
1673 Perl_croak(aTHX_ "Bad hash");
1674 xhv = (XPVHV*)SvANY(hv);
1676 iter = xhv->xhv_aux;
1678 entry = iter->xhv_eiter; /* HvEITER(hv) */
1679 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1681 hv_free_ent(hv, entry);
1683 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1684 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1686 xhv->xhv_aux = S_hv_auxinit(aTHX);
1689 /* used to be xhv->xhv_fill before 5.004_65 */
1690 return XHvTOTALKEYS(xhv);
1694 Perl_hv_riter_p(pTHX_ HV *hv) {
1695 struct xpvhv_aux *iter;
1698 Perl_croak(aTHX_ "Bad hash");
1700 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1702 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1704 return &(iter->xhv_riter);
1708 Perl_hv_eiter_p(pTHX_ HV *hv) {
1709 struct xpvhv_aux *iter;
1712 Perl_croak(aTHX_ "Bad hash");
1714 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1716 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1718 return &(iter->xhv_eiter);
1722 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1723 struct xpvhv_aux *iter;
1726 Perl_croak(aTHX_ "Bad hash");
1729 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1734 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1736 iter->xhv_riter = riter;
1740 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1741 struct xpvhv_aux *iter;
1744 Perl_croak(aTHX_ "Bad hash");
1746 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1748 /* 0 is the default so don't go malloc()ing a new structure just to
1753 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1755 iter->xhv_eiter = eiter;
1760 Perl_hv_name_p(pTHX_ HV *hv)
1762 struct xpvhv_aux *iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1765 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1767 return &(iter->xhv_name);
1771 Perl_hv_name_set(pTHX_ HV *hv, const char *name, STRLEN len, int flags)
1773 struct xpvhv_aux *iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1779 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1781 iter->xhv_name = savepvn(name, len);
1785 =for apidoc hv_iternext
1787 Returns entries from a hash iterator. See C<hv_iterinit>.
1789 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1790 iterator currently points to, without losing your place or invalidating your
1791 iterator. Note that in this case the current entry is deleted from the hash
1792 with your iterator holding the last reference to it. Your iterator is flagged
1793 to free the entry on the next call to C<hv_iternext>, so you must not discard
1794 your iterator immediately else the entry will leak - call C<hv_iternext> to
1795 trigger the resource deallocation.
1801 Perl_hv_iternext(pTHX_ HV *hv)
1803 return hv_iternext_flags(hv, 0);
1807 =for apidoc hv_iternext_flags
1809 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1810 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1811 set the placeholders keys (for restricted hashes) will be returned in addition
1812 to normal keys. By default placeholders are automatically skipped over.
1813 Currently a placeholder is implemented with a value that is
1814 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1815 restricted hashes may change, and the implementation currently is
1816 insufficiently abstracted for any change to be tidy.
1822 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1825 register XPVHV* xhv;
1829 struct xpvhv_aux *iter;
1832 Perl_croak(aTHX_ "Bad hash");
1833 xhv = (XPVHV*)SvANY(hv);
1834 iter = xhv->xhv_aux;
1837 /* Too many things (well, pp_each at least) merrily assume that you can
1838 call iv_iternext without calling hv_iterinit, so we'll have to deal
1841 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1844 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
1846 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1847 SV *key = sv_newmortal();
1849 sv_setsv(key, HeSVKEY_force(entry));
1850 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1856 /* one HE per MAGICAL hash */
1857 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1859 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1861 HeKEY_hek(entry) = hek;
1862 HeKLEN(entry) = HEf_SVKEY;
1864 magic_nextpack((SV*) hv,mg,key);
1866 /* force key to stay around until next time */
1867 HeSVKEY_set(entry, SvREFCNT_inc(key));
1868 return entry; /* beware, hent_val is not set */
1871 SvREFCNT_dec(HeVAL(entry));
1872 Safefree(HeKEY_hek(entry));
1874 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1877 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1878 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1885 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1887 HvARRAY(hv) = (HE**) darray;
1889 /* At start of hash, entry is NULL. */
1892 entry = HeNEXT(entry);
1893 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1895 * Skip past any placeholders -- don't want to include them in
1898 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1899 entry = HeNEXT(entry);
1904 /* OK. Come to the end of the current list. Grab the next one. */
1906 iter->xhv_riter++; /* HvRITER(hv)++ */
1907 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1908 /* There is no next one. End of the hash. */
1909 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1912 entry = (HvARRAY(hv))[iter->xhv_riter];
1914 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1915 /* If we have an entry, but it's a placeholder, don't count it.
1917 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1918 entry = HeNEXT(entry);
1920 /* Will loop again if this linked list starts NULL
1921 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1922 or if we run through it and find only placeholders. */
1925 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1927 hv_free_ent(hv, oldentry);
1930 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1931 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1933 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
1938 =for apidoc hv_iterkey
1940 Returns the key from the current position of the hash iterator. See
1947 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1949 if (HeKLEN(entry) == HEf_SVKEY) {
1951 char *p = SvPV(HeKEY_sv(entry), len);
1956 *retlen = HeKLEN(entry);
1957 return HeKEY(entry);
1961 /* unlike hv_iterval(), this always returns a mortal copy of the key */
1963 =for apidoc hv_iterkeysv
1965 Returns the key as an C<SV*> from the current position of the hash
1966 iterator. The return value will always be a mortal copy of the key. Also
1973 Perl_hv_iterkeysv(pTHX_ register HE *entry)
1975 if (HeKLEN(entry) != HEf_SVKEY) {
1976 HEK *hek = HeKEY_hek(entry);
1977 const int flags = HEK_FLAGS(hek);
1980 if (flags & HVhek_WASUTF8) {
1982 Andreas would like keys he put in as utf8 to come back as utf8
1984 STRLEN utf8_len = HEK_LEN(hek);
1985 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
1987 sv = newSVpvn ((char*)as_utf8, utf8_len);
1989 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
1990 } else if (flags & HVhek_REHASH) {
1991 /* We don't have a pointer to the hv, so we have to replicate the
1992 flag into every HEK. This hv is using custom a hasing
1993 algorithm. Hence we can't return a shared string scalar, as
1994 that would contain the (wrong) hash value, and might get passed
1995 into an hv routine with a regular hash */
1997 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
2001 sv = newSVpvn_share(HEK_KEY(hek),
2002 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
2005 return sv_2mortal(sv);
2007 return sv_mortalcopy(HeKEY_sv(entry));
2011 =for apidoc hv_iterval
2013 Returns the value from the current position of the hash iterator. See
2020 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2022 if (SvRMAGICAL(hv)) {
2023 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2024 SV* sv = sv_newmortal();
2025 if (HeKLEN(entry) == HEf_SVKEY)
2026 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2028 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2032 return HeVAL(entry);
2036 =for apidoc hv_iternextsv
2038 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2045 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2048 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
2050 *key = hv_iterkey(he, retlen);
2051 return hv_iterval(hv, he);
2055 =for apidoc hv_magic
2057 Adds magic to a hash. See C<sv_magic>.
2063 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
2065 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
2068 #if 0 /* use the macro from hv.h instead */
2071 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
2073 return HEK_KEY(share_hek(sv, len, hash));
2078 /* possibly free a shared string if no one has access to it
2079 * len and hash must both be valid for str.
2082 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2084 unshare_hek_or_pvn (NULL, str, len, hash);
2089 Perl_unshare_hek(pTHX_ HEK *hek)
2091 unshare_hek_or_pvn(hek, NULL, 0, 0);
2094 /* possibly free a shared string if no one has access to it
2095 hek if non-NULL takes priority over the other 3, else str, len and hash
2096 are used. If so, len and hash must both be valid for str.
2099 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
2101 register XPVHV* xhv;
2103 register HE **oentry;
2106 bool is_utf8 = FALSE;
2108 const char *save = str;
2111 hash = HEK_HASH(hek);
2112 } else if (len < 0) {
2113 STRLEN tmplen = -len;
2115 /* See the note in hv_fetch(). --jhi */
2116 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2119 k_flags = HVhek_UTF8;
2121 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2124 /* what follows is the moral equivalent of:
2125 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2126 if (--*Svp == Nullsv)
2127 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2129 xhv = (XPVHV*)SvANY(PL_strtab);
2130 /* assert(xhv_array != 0) */
2132 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2134 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2135 if (HeKEY_hek(entry) != hek)
2141 const int flags_masked = k_flags & HVhek_MASK;
2142 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2143 if (HeHASH(entry) != hash) /* strings can't be equal */
2145 if (HeKLEN(entry) != len)
2147 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2149 if (HeKFLAGS(entry) != flags_masked)
2157 if (--HeVAL(entry) == Nullsv) {
2158 *oentry = HeNEXT(entry);
2160 xhv->xhv_fill--; /* HvFILL(hv)-- */
2161 Safefree(HeKEY_hek(entry));
2163 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2167 UNLOCK_STRTAB_MUTEX;
2168 if (!found && ckWARN_d(WARN_INTERNAL))
2169 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2170 "Attempt to free non-existent shared string '%s'%s"
2172 hek ? HEK_KEY(hek) : str,
2173 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2174 if (k_flags & HVhek_FREEKEY)
2178 /* get a (constant) string ptr from the global string table
2179 * string will get added if it is not already there.
2180 * len and hash must both be valid for str.
2183 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2185 bool is_utf8 = FALSE;
2187 const char *save = str;
2190 STRLEN tmplen = -len;
2192 /* See the note in hv_fetch(). --jhi */
2193 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2195 /* If we were able to downgrade here, then than means that we were passed
2196 in a key which only had chars 0-255, but was utf8 encoded. */
2199 /* If we found we were able to downgrade the string to bytes, then
2200 we should flag that it needs upgrading on keys or each. Also flag
2201 that we need share_hek_flags to free the string. */
2203 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2206 return share_hek_flags (str, len, hash, flags);
2210 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2212 register XPVHV* xhv;
2214 register HE **oentry;
2217 const int flags_masked = flags & HVhek_MASK;
2219 /* what follows is the moral equivalent of:
2221 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2222 hv_store(PL_strtab, str, len, Nullsv, hash);
2224 Can't rehash the shared string table, so not sure if it's worth
2225 counting the number of entries in the linked list
2227 xhv = (XPVHV*)SvANY(PL_strtab);
2228 /* assert(xhv_array != 0) */
2230 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2231 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2232 if (HeHASH(entry) != hash) /* strings can't be equal */
2234 if (HeKLEN(entry) != len)
2236 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2238 if (HeKFLAGS(entry) != flags_masked)
2245 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2246 HeVAL(entry) = Nullsv;
2247 HeNEXT(entry) = *oentry;
2249 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2250 if (i) { /* initial entry? */
2251 xhv->xhv_fill++; /* HvFILL(hv)++ */
2252 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2257 ++HeVAL(entry); /* use value slot as REFCNT */
2258 UNLOCK_STRTAB_MUTEX;
2260 if (flags & HVhek_FREEKEY)
2263 return HeKEY_hek(entry);
2267 Perl_hv_placeholders_p(pTHX_ HV *hv)
2270 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2273 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2276 Perl_die(aTHX_ "panic: hv_placeholders_p");
2279 return &(mg->mg_len);
2284 Perl_hv_placeholders_get(pTHX_ HV *hv)
2287 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2289 return mg ? mg->mg_len : 0;
2293 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2296 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2301 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2302 Perl_die(aTHX_ "panic: hv_placeholders_set");
2304 /* else we don't need to add magic to record 0 placeholders. */
2308 =for apidoc hv_assert
2310 Check that a hash is in an internally consistent state.
2316 Perl_hv_assert(pTHX_ HV *hv)
2321 int placeholders = 0;
2324 const I32 riter = HvRITER_get(hv);
2325 HE *eiter = HvEITER_get(hv);
2327 (void)hv_iterinit(hv);
2329 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2330 /* sanity check the values */
2331 if (HeVAL(entry) == &PL_sv_placeholder) {
2336 /* sanity check the keys */
2337 if (HeSVKEY(entry)) {
2338 /* Don't know what to check on SV keys. */
2339 } else if (HeKUTF8(entry)) {
2341 if (HeKWASUTF8(entry)) {
2342 PerlIO_printf(Perl_debug_log,
2343 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2344 (int) HeKLEN(entry), HeKEY(entry));
2347 } else if (HeKWASUTF8(entry)) {
2351 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2352 if (HvUSEDKEYS(hv) != real) {
2353 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2354 (int) real, (int) HvUSEDKEYS(hv));
2357 if (HvPLACEHOLDERS(hv) != placeholders) {
2358 PerlIO_printf(Perl_debug_log,
2359 "Count %d placeholder(s), but hash reports %d\n",
2360 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2364 if (withflags && ! HvHASKFLAGS(hv)) {
2365 PerlIO_printf(Perl_debug_log,
2366 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2373 HvRITER_set(hv, riter); /* Restore hash iterator state */
2374 HvEITER_set(hv, eiter);
2379 * c-indentation-style: bsd
2381 * indent-tabs-mode: t
2384 * ex: set ts=8 sts=4 sw=4 noet: