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_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
129 HE *shared = (HE*)ptr_table_fetch(PL_shared_hek_table, source);
132 /* We already shared this hash key. */
136 shared = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
137 HEK_HASH(source), HEK_FLAGS(source));
138 ptr_table_store(PL_shared_hek_table, source, shared);
140 return HeKEY_hek(shared);
144 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
150 /* look for it in the table first */
151 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
155 /* create anew and remember what it is */
157 ptr_table_store(PL_ptr_table, e, ret);
159 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
160 if (HeKLEN(e) == HEf_SVKEY) {
162 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
163 HeKEY_hek(ret) = (HEK*)k;
164 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
167 /* This is hek_dup inlined, which seems to be important for speed
169 HEK *source = HeKEY_hek(e);
170 HE *shared = (HE*)ptr_table_fetch(PL_shared_hek_table, source);
173 /* We already shared this hash key. */
177 shared = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
178 HEK_HASH(source), HEK_FLAGS(source));
179 ptr_table_store(PL_shared_hek_table, source, shared);
181 HeKEY_hek(ret) = HeKEY_hek(shared);
184 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
186 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
189 #endif /* USE_ITHREADS */
192 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
195 SV *sv = sv_newmortal();
196 if (!(flags & HVhek_FREEKEY)) {
197 sv_setpvn(sv, key, klen);
200 /* Need to free saved eventually assign to mortal SV */
201 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
202 sv_usepvn(sv, (char *) key, klen);
204 if (flags & HVhek_UTF8) {
207 Perl_croak(aTHX_ msg, sv);
210 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
213 #define HV_FETCH_ISSTORE 0x01
214 #define HV_FETCH_ISEXISTS 0x02
215 #define HV_FETCH_LVALUE 0x04
216 #define HV_FETCH_JUST_SV 0x08
221 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
222 the length of the key. The C<hash> parameter is the precomputed hash
223 value; if it is zero then Perl will compute it. The return value will be
224 NULL if the operation failed or if the value did not need to be actually
225 stored within the hash (as in the case of tied hashes). Otherwise it can
226 be dereferenced to get the original C<SV*>. Note that the caller is
227 responsible for suitably incrementing the reference count of C<val> before
228 the call, and decrementing it if the function returned NULL. Effectively
229 a successful hv_store takes ownership of one reference to C<val>. This is
230 usually what you want; a newly created SV has a reference count of one, so
231 if all your code does is create SVs then store them in a hash, hv_store
232 will own the only reference to the new SV, and your code doesn't need to do
233 anything further to tidy up. hv_store is not implemented as a call to
234 hv_store_ent, and does not create a temporary SV for the key, so if your
235 key data is not already in SV form then use hv_store in preference to
238 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
239 information on how to use this function on tied hashes.
245 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
258 hek = hv_fetch_common (hv, NULL, key, klen, flags,
259 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
260 return hek ? &HeVAL(hek) : NULL;
264 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
265 register U32 hash, int flags)
267 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
268 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
269 return hek ? &HeVAL(hek) : NULL;
273 =for apidoc hv_store_ent
275 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
276 parameter is the precomputed hash value; if it is zero then Perl will
277 compute it. The return value is the new hash entry so created. It will be
278 NULL if the operation failed or if the value did not need to be actually
279 stored within the hash (as in the case of tied hashes). Otherwise the
280 contents of the return value can be accessed using the C<He?> macros
281 described here. Note that the caller is responsible for suitably
282 incrementing the reference count of C<val> before the call, and
283 decrementing it if the function returned NULL. Effectively a successful
284 hv_store_ent takes ownership of one reference to C<val>. This is
285 usually what you want; a newly created SV has a reference count of one, so
286 if all your code does is create SVs then store them in a hash, hv_store
287 will own the only reference to the new SV, and your code doesn't need to do
288 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
289 unlike C<val> it does not take ownership of it, so maintaining the correct
290 reference count on C<key> is entirely the caller's responsibility. hv_store
291 is not implemented as a call to hv_store_ent, and does not create a temporary
292 SV for the key, so if your key data is not already in SV form then use
293 hv_store in preference to hv_store_ent.
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
302 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
304 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
308 =for apidoc hv_exists
310 Returns a boolean indicating whether the specified hash key exists. The
311 C<klen> is the length of the key.
317 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
329 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
336 Returns the SV which corresponds to the specified key in the hash. The
337 C<klen> is the length of the key. If C<lval> is set then the fetch will be
338 part of a store. Check that the return value is non-null before
339 dereferencing it to an C<SV*>.
341 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
342 information on how to use this function on tied hashes.
348 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
361 hek = hv_fetch_common (hv, NULL, key, klen, flags,
362 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
364 return hek ? &HeVAL(hek) : NULL;
368 =for apidoc hv_exists_ent
370 Returns a boolean indicating whether the specified hash key exists. C<hash>
371 can be a valid precomputed hash value, or 0 to ask for it to be
378 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
380 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
384 /* returns an HE * structure with the all fields set */
385 /* note that hent_val will be a mortal sv for MAGICAL hashes */
387 =for apidoc hv_fetch_ent
389 Returns the hash entry which corresponds to the specified key in the hash.
390 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
391 if you want the function to compute it. IF C<lval> is set then the fetch
392 will be part of a store. Make sure the return value is non-null before
393 accessing it. The return value when C<tb> is a tied hash is a pointer to a
394 static location, so be sure to make a copy of the structure if you need to
397 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
398 information on how to use this function on tied hashes.
404 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
406 return hv_fetch_common(hv, keysv, NULL, 0, 0,
407 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
411 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
412 int flags, int action, SV *val, register U32 hash)
426 if (flags & HVhek_FREEKEY)
428 key = SvPV(keysv, klen);
430 is_utf8 = (SvUTF8(keysv) != 0);
432 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
435 xhv = (XPVHV*)SvANY(hv);
437 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
439 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
442 /* XXX should be able to skimp on the HE/HEK here when
443 HV_FETCH_JUST_SV is true. */
446 keysv = newSVpvn(key, klen);
451 keysv = newSVsv(keysv);
453 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
455 /* grab a fake HE/HEK pair from the pool or make a new one */
456 entry = PL_hv_fetch_ent_mh;
458 PL_hv_fetch_ent_mh = HeNEXT(entry);
462 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
463 HeKEY_hek(entry) = (HEK*)k;
465 HeNEXT(entry) = Nullhe;
466 HeSVKEY_set(entry, keysv);
468 sv_upgrade(sv, SVt_PVLV);
470 /* so we can free entry when freeing sv */
471 LvTARG(sv) = (SV*)entry;
473 /* XXX remove at some point? */
474 if (flags & HVhek_FREEKEY)
479 #ifdef ENV_IS_CASELESS
480 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
482 for (i = 0; i < klen; ++i)
483 if (isLOWER(key[i])) {
484 /* Would be nice if we had a routine to do the
485 copy and upercase in a single pass through. */
486 const char *nkey = strupr(savepvn(key,klen));
487 /* Note that this fetch is for nkey (the uppercased
488 key) whereas the store is for key (the original) */
489 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
490 HVhek_FREEKEY, /* free nkey */
491 0 /* non-LVAL fetch */,
492 Nullsv /* no value */,
493 0 /* compute hash */);
494 if (!entry && (action & HV_FETCH_LVALUE)) {
495 /* This call will free key if necessary.
496 Do it this way to encourage compiler to tail
498 entry = hv_fetch_common(hv, keysv, key, klen,
499 flags, HV_FETCH_ISSTORE,
502 if (flags & HVhek_FREEKEY)
510 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
511 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
513 /* I don't understand why hv_exists_ent has svret and sv,
514 whereas hv_exists only had one. */
515 svret = sv_newmortal();
518 if (keysv || is_utf8) {
520 keysv = newSVpvn(key, klen);
523 keysv = newSVsv(keysv);
525 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
527 mg_copy((SV*)hv, sv, key, klen);
529 if (flags & HVhek_FREEKEY)
531 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
532 /* This cast somewhat evil, but I'm merely using NULL/
533 not NULL to return the boolean exists.
534 And I know hv is not NULL. */
535 return SvTRUE(svret) ? (HE *)hv : NULL;
537 #ifdef ENV_IS_CASELESS
538 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
539 /* XXX This code isn't UTF8 clean. */
540 const char *keysave = key;
541 /* Will need to free this, so set FREEKEY flag. */
542 key = savepvn(key,klen);
543 key = (const char*)strupr((char*)key);
548 if (flags & HVhek_FREEKEY) {
551 flags |= HVhek_FREEKEY;
555 else if (action & HV_FETCH_ISSTORE) {
558 hv_magic_check (hv, &needs_copy, &needs_store);
560 const bool save_taint = PL_tainted;
561 if (keysv || is_utf8) {
563 keysv = newSVpvn(key, klen);
567 PL_tainted = SvTAINTED(keysv);
568 keysv = sv_2mortal(newSVsv(keysv));
569 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
571 mg_copy((SV*)hv, val, key, klen);
574 TAINT_IF(save_taint);
575 if (!HvARRAY(hv) && !needs_store) {
576 if (flags & HVhek_FREEKEY)
580 #ifdef ENV_IS_CASELESS
581 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
582 /* XXX This code isn't UTF8 clean. */
583 const char *keysave = key;
584 /* Will need to free this, so set FREEKEY flag. */
585 key = savepvn(key,klen);
586 key = (const char*)strupr((char*)key);
591 if (flags & HVhek_FREEKEY) {
594 flags |= HVhek_FREEKEY;
602 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
603 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
604 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
607 Newz(503, HvARRAY(hv),
608 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
610 #ifdef DYNAMIC_ENV_FETCH
611 else if (action & HV_FETCH_ISEXISTS) {
612 /* for an %ENV exists, if we do an insert it's by a recursive
613 store call, so avoid creating HvARRAY(hv) right now. */
617 /* XXX remove at some point? */
618 if (flags & HVhek_FREEKEY)
626 const char *keysave = key;
627 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
631 flags &= ~HVhek_UTF8;
632 if (key != keysave) {
633 if (flags & HVhek_FREEKEY)
635 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
640 PERL_HASH_INTERNAL(hash, key, klen);
641 /* We don't have a pointer to the hv, so we have to replicate the
642 flag into every HEK, so that hv_iterkeysv can see it. */
643 /* And yes, you do need this even though you are not "storing" because
644 you can flip the flags below if doing an lval lookup. (And that
645 was put in to give the semantics Andreas was expecting.) */
646 flags |= HVhek_REHASH;
648 if (keysv && (SvIsCOW_shared_hash(keysv))) {
651 PERL_HASH(hash, key, klen);
655 masked_flags = (flags & HVhek_MASK);
657 #ifdef DYNAMIC_ENV_FETCH
658 if (!HvARRAY(hv)) entry = Null(HE*);
662 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
664 for (; entry; entry = HeNEXT(entry)) {
665 if (HeHASH(entry) != hash) /* strings can't be equal */
667 if (HeKLEN(entry) != (I32)klen)
669 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
671 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
674 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
675 if (HeKFLAGS(entry) != masked_flags) {
676 /* We match if HVhek_UTF8 bit in our flags and hash key's
677 match. But if entry was set previously with HVhek_WASUTF8
678 and key now doesn't (or vice versa) then we should change
679 the key's flag, as this is assignment. */
680 if (HvSHAREKEYS(hv)) {
681 /* Need to swap the key we have for a key with the flags we
682 need. As keys are shared we can't just write to the
683 flag, so we share the new one, unshare the old one. */
684 HEK *new_hek = HeKEY_hek(share_hek_flags(key, klen, hash,
686 unshare_hek (HeKEY_hek(entry));
687 HeKEY_hek(entry) = new_hek;
690 HeKFLAGS(entry) = masked_flags;
691 if (masked_flags & HVhek_ENABLEHVKFLAGS)
694 if (HeVAL(entry) == &PL_sv_placeholder) {
695 /* yes, can store into placeholder slot */
696 if (action & HV_FETCH_LVALUE) {
698 /* This preserves behaviour with the old hv_fetch
699 implementation which at this point would bail out
700 with a break; (at "if we find a placeholder, we
701 pretend we haven't found anything")
703 That break mean that if a placeholder were found, it
704 caused a call into hv_store, which in turn would
705 check magic, and if there is no magic end up pretty
706 much back at this point (in hv_store's code). */
709 /* LVAL fetch which actaully needs a store. */
711 HvPLACEHOLDERS(hv)--;
714 if (val != &PL_sv_placeholder)
715 HvPLACEHOLDERS(hv)--;
718 } else if (action & HV_FETCH_ISSTORE) {
719 SvREFCNT_dec(HeVAL(entry));
722 } else if (HeVAL(entry) == &PL_sv_placeholder) {
723 /* if we find a placeholder, we pretend we haven't found
727 if (flags & HVhek_FREEKEY)
731 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
732 if (!(action & HV_FETCH_ISSTORE)
733 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
735 char *env = PerlEnv_ENVgetenv_len(key,&len);
737 sv = newSVpvn(env,len);
739 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
745 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
746 S_hv_notallowed(aTHX_ flags, key, klen,
747 "Attempt to access disallowed key '%"SVf"' in"
748 " a restricted hash");
750 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
751 /* Not doing some form of store, so return failure. */
752 if (flags & HVhek_FREEKEY)
756 if (action & HV_FETCH_LVALUE) {
759 /* At this point the old hv_fetch code would call to hv_store,
760 which in turn might do some tied magic. So we need to make that
761 magic check happen. */
762 /* gonna assign to this, so it better be there */
763 return hv_fetch_common(hv, keysv, key, klen, flags,
764 HV_FETCH_ISSTORE, val, hash);
765 /* XXX Surely that could leak if the fetch-was-store fails?
766 Just like the hv_fetch. */
770 /* Welcome to hv_store... */
773 /* Not sure if we can get here. I think the only case of oentry being
774 NULL is for %ENV with dynamic env fetch. But that should disappear
775 with magic in the previous code. */
776 Newz(503, HvARRAY(hv),
777 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
781 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
784 /* share_hek_flags will do the free for us. This might be considered
787 HeKEY_hek(entry) = HeKEY_hek(share_hek_flags(key, klen, hash, flags));
788 else /* gotta do the real thing */
789 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
791 HeNEXT(entry) = *oentry;
794 if (val == &PL_sv_placeholder)
795 HvPLACEHOLDERS(hv)++;
796 if (masked_flags & HVhek_ENABLEHVKFLAGS)
800 const HE *counter = HeNEXT(entry);
802 xhv->xhv_keys++; /* HvKEYS(hv)++ */
803 if (!counter) { /* initial entry? */
804 xhv->xhv_fill++; /* HvFILL(hv)++ */
805 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
807 } else if(!HvREHASH(hv)) {
810 while ((counter = HeNEXT(counter)))
813 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
814 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
815 bucket splits on a rehashed hash, as we're not going to
816 split it again, and if someone is lucky (evil) enough to
817 get all the keys in one list they could exhaust our memory
818 as we repeatedly double the number of buckets on every
819 entry. Linear search feels a less worse thing to do. */
829 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
831 const MAGIC *mg = SvMAGIC(hv);
835 if (isUPPER(mg->mg_type)) {
837 switch (mg->mg_type) {
838 case PERL_MAGIC_tied:
840 *needs_store = FALSE;
841 return; /* We've set all there is to set. */
844 mg = mg->mg_moremagic;
849 =for apidoc hv_scalar
851 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
857 Perl_hv_scalar(pTHX_ HV *hv)
862 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
863 sv = magic_scalarpack(hv, mg);
869 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
870 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
878 =for apidoc hv_delete
880 Deletes a key/value pair in the hash. The value SV is removed from the
881 hash and returned to the caller. The C<klen> is the length of the key.
882 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
889 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
896 k_flags |= HVhek_UTF8;
900 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
904 =for apidoc hv_delete_ent
906 Deletes a key/value pair in the hash. The value SV is removed from the
907 hash and returned to the caller. The C<flags> value will normally be zero;
908 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
909 precomputed hash value, or 0 to ask for it to be computed.
915 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
917 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
921 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
922 int k_flags, I32 d_flags, U32 hash)
927 register HE **oentry;
928 HE *const *first_entry;
937 if (k_flags & HVhek_FREEKEY)
939 key = SvPV(keysv, klen);
941 is_utf8 = (SvUTF8(keysv) != 0);
943 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
946 if (SvRMAGICAL(hv)) {
949 hv_magic_check (hv, &needs_copy, &needs_store);
952 entry = hv_fetch_common(hv, keysv, key, klen,
953 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
955 sv = entry ? HeVAL(entry) : NULL;
961 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
962 /* No longer an element */
963 sv_unmagic(sv, PERL_MAGIC_tiedelem);
966 return Nullsv; /* element cannot be deleted */
968 #ifdef ENV_IS_CASELESS
969 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
970 /* XXX This code isn't UTF8 clean. */
971 keysv = sv_2mortal(newSVpvn(key,klen));
972 if (k_flags & HVhek_FREEKEY) {
975 key = strupr(SvPVX(keysv));
984 xhv = (XPVHV*)SvANY(hv);
989 const char *keysave = key;
990 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
993 k_flags |= HVhek_UTF8;
995 k_flags &= ~HVhek_UTF8;
996 if (key != keysave) {
997 if (k_flags & HVhek_FREEKEY) {
998 /* This shouldn't happen if our caller does what we expect,
999 but strictly the API allows it. */
1002 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1004 HvHASKFLAGS_on((SV*)hv);
1008 PERL_HASH_INTERNAL(hash, key, klen);
1010 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1011 hash = SvUVX(keysv);
1013 PERL_HASH(hash, key, klen);
1017 masked_flags = (k_flags & HVhek_MASK);
1019 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1021 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1022 if (HeHASH(entry) != hash) /* strings can't be equal */
1024 if (HeKLEN(entry) != (I32)klen)
1026 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1028 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1031 /* if placeholder is here, it's already been deleted.... */
1032 if (HeVAL(entry) == &PL_sv_placeholder)
1034 if (k_flags & HVhek_FREEKEY)
1038 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1039 S_hv_notallowed(aTHX_ k_flags, key, klen,
1040 "Attempt to delete readonly key '%"SVf"' from"
1041 " a restricted hash");
1043 if (k_flags & HVhek_FREEKEY)
1046 if (d_flags & G_DISCARD)
1049 sv = sv_2mortal(HeVAL(entry));
1050 HeVAL(entry) = &PL_sv_placeholder;
1054 * If a restricted hash, rather than really deleting the entry, put
1055 * a placeholder there. This marks the key as being "approved", so
1056 * we can still access via not-really-existing key without raising
1059 if (SvREADONLY(hv)) {
1060 SvREFCNT_dec(HeVAL(entry));
1061 HeVAL(entry) = &PL_sv_placeholder;
1062 /* We'll be saving this slot, so the number of allocated keys
1063 * doesn't go down, but the number placeholders goes up */
1064 HvPLACEHOLDERS(hv)++;
1066 *oentry = HeNEXT(entry);
1068 xhv->xhv_fill--; /* HvFILL(hv)-- */
1070 if (xhv->xhv_aux && entry
1071 == ((struct xpvhv_aux *)xhv->xhv_aux)->xhv_eiter /* HvEITER(hv) */)
1074 hv_free_ent(hv, entry);
1075 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1076 if (xhv->xhv_keys == 0)
1077 HvHASKFLAGS_off(hv);
1081 if (SvREADONLY(hv)) {
1082 S_hv_notallowed(aTHX_ k_flags, key, klen,
1083 "Attempt to delete disallowed key '%"SVf"' from"
1084 " a restricted hash");
1087 if (k_flags & HVhek_FREEKEY)
1093 S_hsplit(pTHX_ HV *hv)
1095 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1096 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1097 register I32 newsize = oldsize * 2;
1099 char *a = (char*) HvARRAY(hv);
1101 register HE **oentry;
1102 int longest_chain = 0;
1105 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1106 hv, (int) oldsize);*/
1108 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1109 /* Can make this clear any placeholders first for non-restricted hashes,
1110 even though Storable rebuilds restricted hashes by putting in all the
1111 placeholders (first) before turning on the readonly flag, because
1112 Storable always pre-splits the hash. */
1113 hv_clear_placeholders(hv);
1117 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1118 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1124 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1129 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1130 if (oldsize >= 64) {
1131 offer_nice_chunk(HvARRAY(hv),
1132 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1135 Safefree(HvARRAY(hv));
1139 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1140 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1141 HvARRAY(hv) = (HE**) a;
1144 for (i=0; i<oldsize; i++,aep++) {
1145 int left_length = 0;
1146 int right_length = 0;
1150 if (!*aep) /* non-existent */
1153 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1154 if ((HeHASH(entry) & newsize) != (U32)i) {
1155 *oentry = HeNEXT(entry);
1156 HeNEXT(entry) = *bep;
1158 xhv->xhv_fill++; /* HvFILL(hv)++ */
1164 oentry = &HeNEXT(entry);
1168 if (!*aep) /* everything moved */
1169 xhv->xhv_fill--; /* HvFILL(hv)-- */
1170 /* I think we don't actually need to keep track of the longest length,
1171 merely flag if anything is too long. But for the moment while
1172 developing this code I'll track it. */
1173 if (left_length > longest_chain)
1174 longest_chain = left_length;
1175 if (right_length > longest_chain)
1176 longest_chain = right_length;
1180 /* Pick your policy for "hashing isn't working" here: */
1181 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1186 if (hv == PL_strtab) {
1187 /* Urg. Someone is doing something nasty to the string table.
1192 /* Awooga. Awooga. Pathological data. */
1193 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1194 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1197 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1198 was_shared = HvSHAREKEYS(hv);
1201 HvSHAREKEYS_off(hv);
1206 for (i=0; i<newsize; i++,aep++) {
1207 register HE *entry = *aep;
1209 /* We're going to trash this HE's next pointer when we chain it
1210 into the new hash below, so store where we go next. */
1211 HE *next = HeNEXT(entry);
1216 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1221 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1222 hash, HeKFLAGS(entry));
1223 unshare_hek (HeKEY_hek(entry));
1224 HeKEY_hek(entry) = new_hek;
1226 /* Not shared, so simply write the new hash in. */
1227 HeHASH(entry) = hash;
1229 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1230 HEK_REHASH_on(HeKEY_hek(entry));
1231 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1233 /* Copy oentry to the correct new chain. */
1234 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1236 xhv->xhv_fill++; /* HvFILL(hv)++ */
1237 HeNEXT(entry) = *bep;
1243 Safefree (HvARRAY(hv));
1244 HvARRAY(hv) = (HE **)a;
1248 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1250 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1251 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1252 register I32 newsize;
1257 register HE **oentry;
1259 newsize = (I32) newmax; /* possible truncation here */
1260 if (newsize != newmax || newmax <= oldsize)
1262 while ((newsize & (1 + ~newsize)) != newsize) {
1263 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1265 if (newsize < newmax)
1267 if (newsize < newmax)
1268 return; /* overflow detection */
1270 a = (char *) HvARRAY(hv);
1273 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1274 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1280 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1285 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1286 if (oldsize >= 64) {
1287 offer_nice_chunk(HvARRAY(hv),
1288 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1291 Safefree(HvARRAY(hv));
1294 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1297 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1299 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1300 HvARRAY(hv) = (HE **) a;
1301 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1305 for (i=0; i<oldsize; i++,aep++) {
1306 if (!*aep) /* non-existent */
1308 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1310 if ((j = (HeHASH(entry) & newsize)) != i) {
1312 *oentry = HeNEXT(entry);
1313 if (!(HeNEXT(entry) = aep[j]))
1314 xhv->xhv_fill++; /* HvFILL(hv)++ */
1319 oentry = &HeNEXT(entry);
1321 if (!*aep) /* everything moved */
1322 xhv->xhv_fill--; /* HvFILL(hv)-- */
1329 Creates a new HV. The reference count is set to 1.
1338 register XPVHV* xhv;
1340 hv = (HV*)NEWSV(502,0);
1341 sv_upgrade((SV *)hv, SVt_PVHV);
1342 xhv = (XPVHV*)SvANY(hv);
1345 #ifndef NODEFAULT_SHAREKEYS
1346 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1349 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1350 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1356 Perl_newHVhv(pTHX_ HV *ohv)
1359 STRLEN hv_max, hv_fill;
1361 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1363 hv_max = HvMAX(ohv);
1365 if (!SvMAGICAL((SV *)ohv)) {
1366 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1368 const bool shared = !!HvSHAREKEYS(ohv);
1369 HE **ents, **oents = (HE **)HvARRAY(ohv);
1371 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1374 /* In each bucket... */
1375 for (i = 0; i <= hv_max; i++) {
1376 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1383 /* Copy the linked list of entries. */
1384 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1385 const U32 hash = HeHASH(oent);
1386 const char * const key = HeKEY(oent);
1387 const STRLEN len = HeKLEN(oent);
1388 const int flags = HeKFLAGS(oent);
1391 HeVAL(ent) = newSVsv(HeVAL(oent));
1393 = shared ? HeKEY_hek(share_hek_flags(key, len, hash, flags))
1394 : save_hek_flags(key, len, hash, flags);
1405 HvFILL(hv) = hv_fill;
1406 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1410 /* Iterate over ohv, copying keys and values one at a time. */
1412 const I32 riter = HvRITER_get(ohv);
1413 HE * const eiter = HvEITER_get(ohv);
1415 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1416 while (hv_max && hv_max + 1 >= hv_fill * 2)
1417 hv_max = hv_max / 2;
1421 while ((entry = hv_iternext_flags(ohv, 0))) {
1422 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1423 newSVsv(HeVAL(entry)), HeHASH(entry),
1426 HvRITER_set(ohv, riter);
1427 HvEITER_set(ohv, eiter);
1434 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1441 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1442 PL_sub_generation++; /* may be deletion of method from stash */
1444 if (HeKLEN(entry) == HEf_SVKEY) {
1445 SvREFCNT_dec(HeKEY_sv(entry));
1446 Safefree(HeKEY_hek(entry));
1448 else if (HvSHAREKEYS(hv))
1449 unshare_hek(HeKEY_hek(entry));
1451 Safefree(HeKEY_hek(entry));
1456 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1460 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME_get(hv))
1461 PL_sub_generation++; /* may be deletion of method from stash */
1462 sv_2mortal(HeVAL(entry)); /* free between statements */
1463 if (HeKLEN(entry) == HEf_SVKEY) {
1464 sv_2mortal(HeKEY_sv(entry));
1465 Safefree(HeKEY_hek(entry));
1467 else if (HvSHAREKEYS(hv))
1468 unshare_hek(HeKEY_hek(entry));
1470 Safefree(HeKEY_hek(entry));
1475 =for apidoc hv_clear
1477 Clears a hash, making it empty.
1483 Perl_hv_clear(pTHX_ HV *hv)
1486 register XPVHV* xhv;
1490 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1492 xhv = (XPVHV*)SvANY(hv);
1494 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1495 /* restricted hash: convert all keys to placeholders */
1497 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1498 HE *entry = (HvARRAY(hv))[i];
1499 for (; entry; entry = HeNEXT(entry)) {
1500 /* not already placeholder */
1501 if (HeVAL(entry) != &PL_sv_placeholder) {
1502 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1503 SV* keysv = hv_iterkeysv(entry);
1505 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1508 SvREFCNT_dec(HeVAL(entry));
1509 HeVAL(entry) = &PL_sv_placeholder;
1510 HvPLACEHOLDERS(hv)++;
1518 HvPLACEHOLDERS_set(hv, 0);
1520 (void)memzero(HvARRAY(hv),
1521 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1526 HvHASKFLAGS_off(hv);
1530 HvEITER_set(hv, NULL);
1535 =for apidoc hv_clear_placeholders
1537 Clears any placeholders from a hash. If a restricted hash has any of its keys
1538 marked as readonly and the key is subsequently deleted, the key is not actually
1539 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1540 it so it will be ignored by future operations such as iterating over the hash,
1541 but will still allow the hash to have a value reassigned to the key at some
1542 future point. This function clears any such placeholder keys from the hash.
1543 See Hash::Util::lock_keys() for an example of its use.
1549 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1552 I32 items = (I32)HvPLACEHOLDERS_get(hv);
1559 /* Loop down the linked list heads */
1561 HE **oentry = &(HvARRAY(hv))[i];
1562 HE *entry = *oentry;
1567 for (; entry; entry = *oentry) {
1568 if (HeVAL(entry) == &PL_sv_placeholder) {
1569 *oentry = HeNEXT(entry);
1570 if (first && !*oentry)
1571 HvFILL(hv)--; /* This linked list is now empty. */
1572 if (HvEITER_get(hv))
1575 hv_free_ent(hv, entry);
1579 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1580 if (HvKEYS(hv) == 0)
1581 HvHASKFLAGS_off(hv);
1582 HvPLACEHOLDERS_set(hv, 0);
1586 oentry = &HeNEXT(entry);
1591 /* You can't get here, hence assertion should always fail. */
1592 assert (items == 0);
1597 S_hfreeentries(pTHX_ HV *hv)
1599 register HE **array;
1603 struct xpvhv_aux *iter;
1612 array = HvARRAY(hv);
1613 /* make everyone else think the array is empty, so that the destructors
1614 * called for freed entries can't recusively mess with us */
1615 HvARRAY(hv) = Null(HE**);
1617 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1622 register HE *oentry = entry;
1623 entry = HeNEXT(entry);
1624 hv_free_ent(hv, oentry);
1629 entry = array[riter];
1632 HvARRAY(hv) = array;
1634 iter = ((XPVHV*) SvANY(hv))->xhv_aux;
1636 entry = iter->xhv_eiter; /* HvEITER(hv) */
1637 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1639 hv_free_ent(hv, entry);
1642 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1644 ((XPVHV*) SvANY(hv))->xhv_aux = 0;
1649 =for apidoc hv_undef
1657 Perl_hv_undef(pTHX_ HV *hv)
1659 register XPVHV* xhv;
1663 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1664 xhv = (XPVHV*)SvANY(hv);
1666 Safefree(HvARRAY(hv));
1667 if ((name = HvNAME_get(hv))) {
1669 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1670 Perl_hv_name_set(aTHX_ hv, 0, 0, 0);
1672 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1674 HvPLACEHOLDERS_set(hv, 0);
1681 S_hv_auxinit(pTHX) {
1682 struct xpvhv_aux *iter;
1684 New(0, iter, 1, struct xpvhv_aux);
1686 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1687 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1694 =for apidoc hv_iterinit
1696 Prepares a starting point to traverse a hash table. Returns the number of
1697 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1698 currently only meaningful for hashes without tie magic.
1700 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1701 hash buckets that happen to be in use. If you still need that esoteric
1702 value, you can get it through the macro C<HvFILL(tb)>.
1709 Perl_hv_iterinit(pTHX_ HV *hv)
1711 register XPVHV* xhv;
1713 struct xpvhv_aux *iter;
1716 Perl_croak(aTHX_ "Bad hash");
1717 xhv = (XPVHV*)SvANY(hv);
1719 iter = xhv->xhv_aux;
1721 entry = iter->xhv_eiter; /* HvEITER(hv) */
1722 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1724 hv_free_ent(hv, entry);
1726 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1727 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1729 xhv->xhv_aux = S_hv_auxinit(aTHX);
1732 /* used to be xhv->xhv_fill before 5.004_65 */
1733 return HvTOTALKEYS(hv);
1737 Perl_hv_riter_p(pTHX_ HV *hv) {
1738 struct xpvhv_aux *iter;
1741 Perl_croak(aTHX_ "Bad hash");
1743 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1745 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1747 return &(iter->xhv_riter);
1751 Perl_hv_eiter_p(pTHX_ HV *hv) {
1752 struct xpvhv_aux *iter;
1755 Perl_croak(aTHX_ "Bad hash");
1757 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1759 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1761 return &(iter->xhv_eiter);
1765 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1766 struct xpvhv_aux *iter;
1769 Perl_croak(aTHX_ "Bad hash");
1772 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1777 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1779 iter->xhv_riter = riter;
1783 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1784 struct xpvhv_aux *iter;
1787 Perl_croak(aTHX_ "Bad hash");
1789 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1791 /* 0 is the default so don't go malloc()ing a new structure just to
1796 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1798 iter->xhv_eiter = eiter;
1802 Perl_hv_name_set(pTHX_ HV *hv, const char *name, I32 len, int flags)
1804 struct xpvhv_aux *iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1808 if (iter->xhv_name) {
1809 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1815 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1817 PERL_HASH(hash, name, len);
1818 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
1822 =for apidoc hv_iternext
1824 Returns entries from a hash iterator. See C<hv_iterinit>.
1826 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1827 iterator currently points to, without losing your place or invalidating your
1828 iterator. Note that in this case the current entry is deleted from the hash
1829 with your iterator holding the last reference to it. Your iterator is flagged
1830 to free the entry on the next call to C<hv_iternext>, so you must not discard
1831 your iterator immediately else the entry will leak - call C<hv_iternext> to
1832 trigger the resource deallocation.
1838 Perl_hv_iternext(pTHX_ HV *hv)
1840 return hv_iternext_flags(hv, 0);
1844 =for apidoc hv_iternext_flags
1846 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1847 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1848 set the placeholders keys (for restricted hashes) will be returned in addition
1849 to normal keys. By default placeholders are automatically skipped over.
1850 Currently a placeholder is implemented with a value that is
1851 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1852 restricted hashes may change, and the implementation currently is
1853 insufficiently abstracted for any change to be tidy.
1859 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1862 register XPVHV* xhv;
1866 struct xpvhv_aux *iter;
1869 Perl_croak(aTHX_ "Bad hash");
1870 xhv = (XPVHV*)SvANY(hv);
1871 iter = xhv->xhv_aux;
1874 /* Too many things (well, pp_each at least) merrily assume that you can
1875 call iv_iternext without calling hv_iterinit, so we'll have to deal
1878 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1881 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
1883 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1884 SV *key = sv_newmortal();
1886 sv_setsv(key, HeSVKEY_force(entry));
1887 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1893 /* one HE per MAGICAL hash */
1894 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1896 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1898 HeKEY_hek(entry) = hek;
1899 HeKLEN(entry) = HEf_SVKEY;
1901 magic_nextpack((SV*) hv,mg,key);
1903 /* force key to stay around until next time */
1904 HeSVKEY_set(entry, SvREFCNT_inc(key));
1905 return entry; /* beware, hent_val is not set */
1908 SvREFCNT_dec(HeVAL(entry));
1909 Safefree(HeKEY_hek(entry));
1911 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1914 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1915 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1922 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1924 HvARRAY(hv) = (HE**) darray;
1926 /* At start of hash, entry is NULL. */
1929 entry = HeNEXT(entry);
1930 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1932 * Skip past any placeholders -- don't want to include them in
1935 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1936 entry = HeNEXT(entry);
1941 /* OK. Come to the end of the current list. Grab the next one. */
1943 iter->xhv_riter++; /* HvRITER(hv)++ */
1944 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1945 /* There is no next one. End of the hash. */
1946 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1949 entry = (HvARRAY(hv))[iter->xhv_riter];
1951 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1952 /* If we have an entry, but it's a placeholder, don't count it.
1954 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1955 entry = HeNEXT(entry);
1957 /* Will loop again if this linked list starts NULL
1958 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1959 or if we run through it and find only placeholders. */
1962 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1964 hv_free_ent(hv, oldentry);
1967 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1968 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1970 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
1975 =for apidoc hv_iterkey
1977 Returns the key from the current position of the hash iterator. See
1984 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1986 if (HeKLEN(entry) == HEf_SVKEY) {
1988 char *p = SvPV(HeKEY_sv(entry), len);
1993 *retlen = HeKLEN(entry);
1994 return HeKEY(entry);
1998 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2000 =for apidoc hv_iterkeysv
2002 Returns the key as an C<SV*> from the current position of the hash
2003 iterator. The return value will always be a mortal copy of the key. Also
2010 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2012 if (HeKLEN(entry) != HEf_SVKEY) {
2013 HEK *hek = HeKEY_hek(entry);
2014 const int flags = HEK_FLAGS(hek);
2017 if (flags & HVhek_WASUTF8) {
2019 Andreas would like keys he put in as utf8 to come back as utf8
2021 STRLEN utf8_len = HEK_LEN(hek);
2022 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
2024 sv = newSVpvn ((char*)as_utf8, utf8_len);
2026 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
2027 } else if (flags & HVhek_REHASH) {
2028 /* We don't have a pointer to the hv, so we have to replicate the
2029 flag into every HEK. This hv is using custom a hasing
2030 algorithm. Hence we can't return a shared string scalar, as
2031 that would contain the (wrong) hash value, and might get passed
2032 into an hv routine with a regular hash */
2034 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
2038 sv = newSVpvn_share(HEK_KEY(hek),
2039 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
2042 return sv_2mortal(sv);
2044 return sv_mortalcopy(HeKEY_sv(entry));
2048 =for apidoc hv_iterval
2050 Returns the value from the current position of the hash iterator. See
2057 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2059 if (SvRMAGICAL(hv)) {
2060 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2061 SV* sv = sv_newmortal();
2062 if (HeKLEN(entry) == HEf_SVKEY)
2063 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2065 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2069 return HeVAL(entry);
2073 =for apidoc hv_iternextsv
2075 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2082 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2085 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
2087 *key = hv_iterkey(he, retlen);
2088 return hv_iterval(hv, he);
2092 =for apidoc hv_magic
2094 Adds magic to a hash. See C<sv_magic>.
2100 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
2102 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
2105 #if 0 /* use the macro from hv.h instead */
2108 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
2110 return HEK_KEY(share_hek(sv, len, hash));
2115 /* possibly free a shared string if no one has access to it
2116 * len and hash must both be valid for str.
2119 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2121 unshare_hek_or_pvn (NULL, str, len, hash);
2126 Perl_unshare_hek(pTHX_ HEK *hek)
2128 unshare_hek_or_pvn(hek, NULL, 0, 0);
2131 /* possibly free a shared string if no one has access to it
2132 hek if non-NULL takes priority over the other 3, else str, len and hash
2133 are used. If so, len and hash must both be valid for str.
2136 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
2138 register XPVHV* xhv;
2140 register HE **oentry;
2143 bool is_utf8 = FALSE;
2145 const char *save = str;
2148 hash = HEK_HASH(hek);
2149 } else if (len < 0) {
2150 STRLEN tmplen = -len;
2152 /* See the note in hv_fetch(). --jhi */
2153 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2156 k_flags = HVhek_UTF8;
2158 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2161 /* what follows is the moral equivalent of:
2162 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2163 if (--*Svp == Nullsv)
2164 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2166 xhv = (XPVHV*)SvANY(PL_strtab);
2167 /* assert(xhv_array != 0) */
2169 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2171 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2172 if (HeKEY_hek(entry) != hek)
2178 const int flags_masked = k_flags & HVhek_MASK;
2179 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2180 if (HeHASH(entry) != hash) /* strings can't be equal */
2182 if (HeKLEN(entry) != len)
2184 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2186 if (HeKFLAGS(entry) != flags_masked)
2194 if (--HeVAL(entry) == Nullsv) {
2195 *oentry = HeNEXT(entry);
2197 /* There are now no entries in our slot. */
2198 xhv->xhv_fill--; /* HvFILL(hv)-- */
2200 Safefree(HeKEY_hek(entry));
2202 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2206 UNLOCK_STRTAB_MUTEX;
2207 if (!found && ckWARN_d(WARN_INTERNAL))
2208 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2209 "Attempt to free non-existent shared string '%s'%s"
2211 hek ? HEK_KEY(hek) : str,
2212 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2213 if (k_flags & HVhek_FREEKEY)
2217 /* get a (constant) string ptr from the global string table
2218 * string will get added if it is not already there.
2219 * len and hash must both be valid for str.
2222 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2224 bool is_utf8 = FALSE;
2226 const char *save = str;
2229 STRLEN tmplen = -len;
2231 /* See the note in hv_fetch(). --jhi */
2232 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2234 /* If we were able to downgrade here, then than means that we were passed
2235 in a key which only had chars 0-255, but was utf8 encoded. */
2238 /* If we found we were able to downgrade the string to bytes, then
2239 we should flag that it needs upgrading on keys or each. Also flag
2240 that we need share_hek_flags to free the string. */
2242 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2245 return HeKEY_hek(share_hek_flags (str, len, hash, flags));
2249 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2251 register XPVHV* xhv;
2253 register HE **oentry;
2255 const int flags_masked = flags & HVhek_MASK;
2257 /* what follows is the moral equivalent of:
2259 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2260 hv_store(PL_strtab, str, len, Nullsv, hash);
2262 Can't rehash the shared string table, so not sure if it's worth
2263 counting the number of entries in the linked list
2265 xhv = (XPVHV*)SvANY(PL_strtab);
2266 /* assert(xhv_array != 0) */
2268 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2269 for (entry = *oentry; entry; entry = HeNEXT(entry)) {
2270 if (HeHASH(entry) != hash) /* strings can't be equal */
2272 if (HeKLEN(entry) != len)
2274 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2276 if (HeKFLAGS(entry) != flags_masked)
2282 /* What used to be head of the list.
2283 If this is NULL, then we're the first entry for this slot, which
2284 means we need to increate fill. */
2285 const HE *old_first = *oentry;
2287 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2288 HeVAL(entry) = Nullsv;
2289 HeNEXT(entry) = *oentry;
2291 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2292 if (!old_first) { /* initial entry? */
2293 xhv->xhv_fill++; /* HvFILL(hv)++ */
2294 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2299 ++HeVAL(entry); /* use value slot as REFCNT */
2300 UNLOCK_STRTAB_MUTEX;
2302 if (flags & HVhek_FREEKEY)
2309 Perl_hv_placeholders_p(pTHX_ HV *hv)
2312 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2315 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2318 Perl_die(aTHX_ "panic: hv_placeholders_p");
2321 return &(mg->mg_len);
2326 Perl_hv_placeholders_get(pTHX_ HV *hv)
2329 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2331 return mg ? mg->mg_len : 0;
2335 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2338 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2343 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2344 Perl_die(aTHX_ "panic: hv_placeholders_set");
2346 /* else we don't need to add magic to record 0 placeholders. */
2350 =for apidoc hv_assert
2352 Check that a hash is in an internally consistent state.
2358 Perl_hv_assert(pTHX_ HV *hv)
2363 int placeholders = 0;
2366 const I32 riter = HvRITER_get(hv);
2367 HE *eiter = HvEITER_get(hv);
2369 (void)hv_iterinit(hv);
2371 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2372 /* sanity check the values */
2373 if (HeVAL(entry) == &PL_sv_placeholder) {
2378 /* sanity check the keys */
2379 if (HeSVKEY(entry)) {
2380 /* Don't know what to check on SV keys. */
2381 } else if (HeKUTF8(entry)) {
2383 if (HeKWASUTF8(entry)) {
2384 PerlIO_printf(Perl_debug_log,
2385 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2386 (int) HeKLEN(entry), HeKEY(entry));
2389 } else if (HeKWASUTF8(entry)) {
2393 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2394 if (HvUSEDKEYS(hv) != real) {
2395 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2396 (int) real, (int) HvUSEDKEYS(hv));
2399 if (HvPLACEHOLDERS_get(hv) != placeholders) {
2400 PerlIO_printf(Perl_debug_log,
2401 "Count %d placeholder(s), but hash reports %d\n",
2402 (int) placeholders, (int) HvPLACEHOLDERS_get(hv));
2406 if (withflags && ! HvHASKFLAGS(hv)) {
2407 PerlIO_printf(Perl_debug_log,
2408 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2415 HvRITER_set(hv, riter); /* Restore hash iterator state */
2416 HvEITER_set(hv, eiter);
2421 * c-indentation-style: bsd
2423 * indent-tabs-mode: t
2426 * ex: set ts=8 sts=4 sw=4 noet: