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
44 PL_he_root = HeNEXT(he);
53 HeNEXT(p) = (HE*)PL_he_root;
64 New(54, ptr, 1008/sizeof(XPV), XPV);
65 ptr->xpv_pv = (char*)PL_he_arenaroot;
66 PL_he_arenaroot = ptr;
69 heend = &he[1008 / sizeof(HE) - 1];
72 HeNEXT(he) = (HE*)(he + 1);
80 #define new_HE() (HE*)safemalloc(sizeof(HE))
81 #define del_HE(p) safefree((char*)p)
85 #define new_HE() new_he()
86 #define del_HE(p) del_he(p)
91 S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
93 const int flags_masked = flags & HVhek_MASK;
97 New(54, k, HEK_BASESIZE + len + 2, char);
99 Copy(str, HEK_KEY(hek), len, char);
100 HEK_KEY(hek)[len] = 0;
102 HEK_HASH(hek) = hash;
103 HEK_FLAGS(hek) = (unsigned char)flags_masked;
105 if (flags & HVhek_FREEKEY)
110 /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
114 Perl_free_tied_hv_pool(pTHX)
117 HE *he = PL_hv_fetch_ent_mh;
119 Safefree(HeKEY_hek(he));
124 PL_hv_fetch_ent_mh = Nullhe;
127 #if defined(USE_ITHREADS)
129 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
135 /* look for it in the table first */
136 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
140 /* create anew and remember what it is */
142 ptr_table_store(PL_ptr_table, e, ret);
144 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
145 if (HeKLEN(e) == HEf_SVKEY) {
147 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
148 HeKEY_hek(ret) = (HEK*)k;
149 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
152 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
155 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
157 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
160 #endif /* USE_ITHREADS */
163 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
166 SV *sv = sv_newmortal(), *esv = sv_newmortal();
167 if (!(flags & HVhek_FREEKEY)) {
168 sv_setpvn(sv, key, klen);
171 /* Need to free saved eventually assign to mortal SV */
172 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
173 sv_usepvn(sv, (char *) key, klen);
175 if (flags & HVhek_UTF8) {
178 Perl_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg);
179 Perl_croak(aTHX_ SvPVX(esv), sv);
182 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
185 #define HV_FETCH_ISSTORE 0x01
186 #define HV_FETCH_ISEXISTS 0x02
187 #define HV_FETCH_LVALUE 0x04
188 #define HV_FETCH_JUST_SV 0x08
193 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
194 the length of the key. The C<hash> parameter is the precomputed hash
195 value; if it is zero then Perl will compute it. The return value will be
196 NULL if the operation failed or if the value did not need to be actually
197 stored within the hash (as in the case of tied hashes). Otherwise it can
198 be dereferenced to get the original C<SV*>. Note that the caller is
199 responsible for suitably incrementing the reference count of C<val> before
200 the call, and decrementing it if the function returned NULL. Effectively
201 a successful hv_store takes ownership of one reference to C<val>. This is
202 usually what you want; a newly created SV has a reference count of one, so
203 if all your code does is create SVs then store them in a hash, hv_store
204 will own the only reference to the new SV, and your code doesn't need to do
205 anything further to tidy up. hv_store is not implemented as a call to
206 hv_store_ent, and does not create a temporary SV for the key, so if your
207 key data is not already in SV form then use hv_store in preference to
210 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
211 information on how to use this function on tied hashes.
217 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
230 hek = hv_fetch_common (hv, NULL, key, klen, flags,
231 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
232 return hek ? &HeVAL(hek) : NULL;
236 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
237 register U32 hash, int flags)
239 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
240 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
241 return hek ? &HeVAL(hek) : NULL;
245 =for apidoc hv_store_ent
247 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
248 parameter is the precomputed hash value; if it is zero then Perl will
249 compute it. The return value is the new hash entry so created. It will be
250 NULL if the operation failed or if the value did not need to be actually
251 stored within the hash (as in the case of tied hashes). Otherwise the
252 contents of the return value can be accessed using the C<He?> macros
253 described here. Note that the caller is responsible for suitably
254 incrementing the reference count of C<val> before the call, and
255 decrementing it if the function returned NULL. Effectively a successful
256 hv_store_ent takes ownership of one reference to C<val>. This is
257 usually what you want; a newly created SV has a reference count of one, so
258 if all your code does is create SVs then store them in a hash, hv_store
259 will own the only reference to the new SV, and your code doesn't need to do
260 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
261 unlike C<val> it does not take ownership of it, so maintaining the correct
262 reference count on C<key> is entirely the caller's responsibility. hv_store
263 is not implemented as a call to hv_store_ent, and does not create a temporary
264 SV for the key, so if your key data is not already in SV form then use
265 hv_store in preference to hv_store_ent.
267 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
268 information on how to use this function on tied hashes.
274 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
276 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
280 =for apidoc hv_exists
282 Returns a boolean indicating whether the specified hash key exists. The
283 C<klen> is the length of the key.
289 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
301 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
308 Returns the SV which corresponds to the specified key in the hash. The
309 C<klen> is the length of the key. If C<lval> is set then the fetch will be
310 part of a store. Check that the return value is non-null before
311 dereferencing it to an C<SV*>.
313 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
314 information on how to use this function on tied hashes.
320 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
333 hek = hv_fetch_common (hv, NULL, key, klen, flags,
334 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
336 return hek ? &HeVAL(hek) : NULL;
340 =for apidoc hv_exists_ent
342 Returns a boolean indicating whether the specified hash key exists. C<hash>
343 can be a valid precomputed hash value, or 0 to ask for it to be
350 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
352 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
356 /* returns an HE * structure with the all fields set */
357 /* note that hent_val will be a mortal sv for MAGICAL hashes */
359 =for apidoc hv_fetch_ent
361 Returns the hash entry which corresponds to the specified key in the hash.
362 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
363 if you want the function to compute it. IF C<lval> is set then the fetch
364 will be part of a store. Make sure the return value is non-null before
365 accessing it. The return value when C<tb> is a tied hash is a pointer to a
366 static location, so be sure to make a copy of the structure if you need to
369 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
370 information on how to use this function on tied hashes.
376 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
378 return hv_fetch_common(hv, keysv, NULL, 0, 0,
379 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
383 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
384 int flags, int action, SV *val, register U32 hash)
399 if (flags & HVhek_FREEKEY)
401 key = SvPV(keysv, klen);
403 is_utf8 = (SvUTF8(keysv) != 0);
405 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
408 xhv = (XPVHV*)SvANY(hv);
410 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
412 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
415 /* XXX should be able to skimp on the HE/HEK here when
416 HV_FETCH_JUST_SV is true. */
419 keysv = newSVpvn(key, klen);
424 keysv = newSVsv(keysv);
426 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
428 /* grab a fake HE/HEK pair from the pool or make a new one */
429 entry = PL_hv_fetch_ent_mh;
431 PL_hv_fetch_ent_mh = HeNEXT(entry);
435 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
436 HeKEY_hek(entry) = (HEK*)k;
438 HeNEXT(entry) = Nullhe;
439 HeSVKEY_set(entry, keysv);
441 sv_upgrade(sv, SVt_PVLV);
443 /* so we can free entry when freeing sv */
444 LvTARG(sv) = (SV*)entry;
446 /* XXX remove at some point? */
447 if (flags & HVhek_FREEKEY)
452 #ifdef ENV_IS_CASELESS
453 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
455 for (i = 0; i < klen; ++i)
456 if (isLOWER(key[i])) {
457 /* Would be nice if we had a routine to do the
458 copy and upercase in a single pass through. */
459 const char *nkey = strupr(savepvn(key,klen));
460 /* Note that this fetch is for nkey (the uppercased
461 key) whereas the store is for key (the original) */
462 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
463 HVhek_FREEKEY, /* free nkey */
464 0 /* non-LVAL fetch */,
465 Nullsv /* no value */,
466 0 /* compute hash */);
467 if (!entry && (action & HV_FETCH_LVALUE)) {
468 /* This call will free key if necessary.
469 Do it this way to encourage compiler to tail
471 entry = hv_fetch_common(hv, keysv, key, klen,
472 flags, HV_FETCH_ISSTORE,
475 if (flags & HVhek_FREEKEY)
483 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
484 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
486 /* I don't understand why hv_exists_ent has svret and sv,
487 whereas hv_exists only had one. */
488 svret = sv_newmortal();
491 if (keysv || is_utf8) {
493 keysv = newSVpvn(key, klen);
496 keysv = newSVsv(keysv);
498 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
500 mg_copy((SV*)hv, sv, key, klen);
502 if (flags & HVhek_FREEKEY)
504 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
505 /* This cast somewhat evil, but I'm merely using NULL/
506 not NULL to return the boolean exists.
507 And I know hv is not NULL. */
508 return SvTRUE(svret) ? (HE *)hv : NULL;
510 #ifdef ENV_IS_CASELESS
511 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
512 /* XXX This code isn't UTF8 clean. */
513 const char *keysave = key;
514 /* Will need to free this, so set FREEKEY flag. */
515 key = savepvn(key,klen);
516 key = (const char*)strupr((char*)key);
521 if (flags & HVhek_FREEKEY) {
524 flags |= HVhek_FREEKEY;
528 else if (action & HV_FETCH_ISSTORE) {
531 hv_magic_check (hv, &needs_copy, &needs_store);
533 bool save_taint = PL_tainted;
534 if (keysv || is_utf8) {
536 keysv = newSVpvn(key, klen);
540 PL_tainted = SvTAINTED(keysv);
541 keysv = sv_2mortal(newSVsv(keysv));
542 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
544 mg_copy((SV*)hv, val, key, klen);
547 TAINT_IF(save_taint);
548 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) {
549 if (flags & HVhek_FREEKEY)
553 #ifdef ENV_IS_CASELESS
554 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
555 /* XXX This code isn't UTF8 clean. */
556 const char *keysave = key;
557 /* Will need to free this, so set FREEKEY flag. */
558 key = savepvn(key,klen);
559 key = (const char*)strupr((char*)key);
564 if (flags & HVhek_FREEKEY) {
567 flags |= HVhek_FREEKEY;
574 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
575 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
576 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
577 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
580 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
581 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
583 #ifdef DYNAMIC_ENV_FETCH
584 else if (action & HV_FETCH_ISEXISTS) {
585 /* for an %ENV exists, if we do an insert it's by a recursive
586 store call, so avoid creating HvARRAY(hv) right now. */
590 /* XXX remove at some point? */
591 if (flags & HVhek_FREEKEY)
599 const char *keysave = key;
600 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
604 flags &= ~HVhek_UTF8;
605 if (key != keysave) {
606 if (flags & HVhek_FREEKEY)
608 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
613 PERL_HASH_INTERNAL(hash, key, klen);
614 /* We don't have a pointer to the hv, so we have to replicate the
615 flag into every HEK, so that hv_iterkeysv can see it. */
616 /* And yes, you do need this even though you are not "storing" because
617 you can flip the flags below if doing an lval lookup. (And that
618 was put in to give the semantics Andreas was expecting.) */
619 flags |= HVhek_REHASH;
621 if (keysv && (SvIsCOW_shared_hash(keysv))) {
624 PERL_HASH(hash, key, klen);
628 masked_flags = (flags & HVhek_MASK);
631 #ifdef DYNAMIC_ENV_FETCH
632 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
636 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
637 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
639 for (; entry; ++n_links, entry = HeNEXT(entry)) {
640 if (HeHASH(entry) != hash) /* strings can't be equal */
642 if (HeKLEN(entry) != (I32)klen)
644 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
646 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
649 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
650 if (HeKFLAGS(entry) != masked_flags) {
651 /* We match if HVhek_UTF8 bit in our flags and hash key's
652 match. But if entry was set previously with HVhek_WASUTF8
653 and key now doesn't (or vice versa) then we should change
654 the key's flag, as this is assignment. */
655 if (HvSHAREKEYS(hv)) {
656 /* Need to swap the key we have for a key with the flags we
657 need. As keys are shared we can't just write to the
658 flag, so we share the new one, unshare the old one. */
659 HEK *new_hek = share_hek_flags(key, klen, hash,
661 unshare_hek (HeKEY_hek(entry));
662 HeKEY_hek(entry) = new_hek;
665 HeKFLAGS(entry) = masked_flags;
666 if (masked_flags & HVhek_ENABLEHVKFLAGS)
669 if (HeVAL(entry) == &PL_sv_placeholder) {
670 /* yes, can store into placeholder slot */
671 if (action & HV_FETCH_LVALUE) {
673 /* This preserves behaviour with the old hv_fetch
674 implementation which at this point would bail out
675 with a break; (at "if we find a placeholder, we
676 pretend we haven't found anything")
678 That break mean that if a placeholder were found, it
679 caused a call into hv_store, which in turn would
680 check magic, and if there is no magic end up pretty
681 much back at this point (in hv_store's code). */
684 /* LVAL fetch which actaully needs a store. */
686 xhv->xhv_placeholders--;
689 if (val != &PL_sv_placeholder)
690 xhv->xhv_placeholders--;
693 } else if (action & HV_FETCH_ISSTORE) {
694 SvREFCNT_dec(HeVAL(entry));
697 } else if (HeVAL(entry) == &PL_sv_placeholder) {
698 /* if we find a placeholder, we pretend we haven't found
702 if (flags & HVhek_FREEKEY)
706 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
707 if (!(action & HV_FETCH_ISSTORE)
708 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
710 char *env = PerlEnv_ENVgetenv_len(key,&len);
712 sv = newSVpvn(env,len);
714 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
720 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
721 S_hv_notallowed(aTHX_ flags, key, klen,
722 "access disallowed key '%"SVf"' in"
725 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
726 /* Not doing some form of store, so return failure. */
727 if (flags & HVhek_FREEKEY)
731 if (action & HV_FETCH_LVALUE) {
734 /* At this point the old hv_fetch code would call to hv_store,
735 which in turn might do some tied magic. So we need to make that
736 magic check happen. */
737 /* gonna assign to this, so it better be there */
738 return hv_fetch_common(hv, keysv, key, klen, flags,
739 HV_FETCH_ISSTORE, val, hash);
740 /* XXX Surely that could leak if the fetch-was-store fails?
741 Just like the hv_fetch. */
745 /* Welcome to hv_store... */
747 if (!xhv->xhv_array) {
748 /* Not sure if we can get here. I think the only case of oentry being
749 NULL is for %ENV with dynamic env fetch. But that should disappear
750 with magic in the previous code. */
751 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
752 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
756 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
759 /* share_hek_flags will do the free for us. This might be considered
762 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
763 else /* gotta do the real thing */
764 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
766 HeNEXT(entry) = *oentry;
769 if (val == &PL_sv_placeholder)
770 xhv->xhv_placeholders++;
771 if (masked_flags & HVhek_ENABLEHVKFLAGS)
774 xhv->xhv_keys++; /* HvKEYS(hv)++ */
775 if (!n_links) { /* initial entry? */
776 xhv->xhv_fill++; /* HvFILL(hv)++ */
777 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
778 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
779 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
780 splits on a rehashed hash, as we're not going to split it again,
781 and if someone is lucky (evil) enough to get all the keys in one
782 list they could exhaust our memory as we repeatedly double the
783 number of buckets on every entry. Linear search feels a less worse
792 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
794 MAGIC *mg = SvMAGIC(hv);
798 if (isUPPER(mg->mg_type)) {
800 switch (mg->mg_type) {
801 case PERL_MAGIC_tied:
803 *needs_store = FALSE;
806 mg = mg->mg_moremagic;
811 =for apidoc hv_scalar
813 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
819 Perl_hv_scalar(pTHX_ HV *hv)
824 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
825 sv = magic_scalarpack(hv, mg);
831 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
832 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
840 =for apidoc hv_delete
842 Deletes a key/value pair in the hash. The value SV is removed from the
843 hash and returned to the caller. The C<klen> is the length of the key.
844 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
851 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
858 k_flags |= HVhek_UTF8;
862 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
866 =for apidoc hv_delete_ent
868 Deletes a key/value pair in the hash. The value SV is removed from the
869 hash and returned to the caller. The C<flags> value will normally be zero;
870 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
871 precomputed hash value, or 0 to ask for it to be computed.
877 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
879 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
883 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
884 int k_flags, I32 d_flags, U32 hash)
890 register HE **oentry;
899 if (k_flags & HVhek_FREEKEY)
901 key = SvPV(keysv, klen);
903 is_utf8 = (SvUTF8(keysv) != 0);
905 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
908 if (SvRMAGICAL(hv)) {
911 hv_magic_check (hv, &needs_copy, &needs_store);
914 entry = hv_fetch_common(hv, keysv, key, klen,
915 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
917 sv = entry ? HeVAL(entry) : NULL;
923 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
924 /* No longer an element */
925 sv_unmagic(sv, PERL_MAGIC_tiedelem);
928 return Nullsv; /* element cannot be deleted */
930 #ifdef ENV_IS_CASELESS
931 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
932 /* XXX This code isn't UTF8 clean. */
933 keysv = sv_2mortal(newSVpvn(key,klen));
934 if (k_flags & HVhek_FREEKEY) {
937 key = strupr(SvPVX(keysv));
946 xhv = (XPVHV*)SvANY(hv);
947 if (!xhv->xhv_array /* !HvARRAY(hv) */)
951 const char *keysave = key;
952 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
955 k_flags |= HVhek_UTF8;
957 k_flags &= ~HVhek_UTF8;
958 if (key != keysave) {
959 if (k_flags & HVhek_FREEKEY) {
960 /* This shouldn't happen if our caller does what we expect,
961 but strictly the API allows it. */
964 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
966 HvHASKFLAGS_on((SV*)hv);
970 PERL_HASH_INTERNAL(hash, key, klen);
972 if (keysv && (SvIsCOW_shared_hash(keysv))) {
975 PERL_HASH(hash, key, klen);
979 masked_flags = (k_flags & HVhek_MASK);
981 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
982 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
985 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
986 if (HeHASH(entry) != hash) /* strings can't be equal */
988 if (HeKLEN(entry) != (I32)klen)
990 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
992 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
995 /* if placeholder is here, it's already been deleted.... */
996 if (HeVAL(entry) == &PL_sv_placeholder)
998 if (k_flags & HVhek_FREEKEY)
1002 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1003 S_hv_notallowed(aTHX_ k_flags, key, klen,
1004 "delete readonly key '%"SVf"' from"
1007 if (k_flags & HVhek_FREEKEY)
1010 if (d_flags & G_DISCARD)
1013 sv = sv_2mortal(HeVAL(entry));
1014 HeVAL(entry) = &PL_sv_placeholder;
1018 * If a restricted hash, rather than really deleting the entry, put
1019 * a placeholder there. This marks the key as being "approved", so
1020 * we can still access via not-really-existing key without raising
1023 if (SvREADONLY(hv)) {
1024 SvREFCNT_dec(HeVAL(entry));
1025 HeVAL(entry) = &PL_sv_placeholder;
1026 /* We'll be saving this slot, so the number of allocated keys
1027 * doesn't go down, but the number placeholders goes up */
1028 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1030 *oentry = HeNEXT(entry);
1032 xhv->xhv_fill--; /* HvFILL(hv)-- */
1033 if (entry == xhv->xhv_eiter /* HvEITER(hv) */)
1036 hv_free_ent(hv, entry);
1037 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1038 if (xhv->xhv_keys == 0)
1039 HvHASKFLAGS_off(hv);
1043 if (SvREADONLY(hv)) {
1044 S_hv_notallowed(aTHX_ k_flags, key, klen,
1045 "delete disallowed key '%"SVf"' from"
1049 if (k_flags & HVhek_FREEKEY)
1055 S_hsplit(pTHX_ HV *hv)
1057 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1058 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1059 register I32 newsize = oldsize * 2;
1061 register char *a = xhv->xhv_array; /* HvARRAY(hv) */
1065 register HE **oentry;
1066 int longest_chain = 0;
1069 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1070 hv, (int) oldsize);*/
1072 if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) {
1073 /* Can make this clear any placeholders first for non-restricted hashes,
1074 even though Storable rebuilds restricted hashes by putting in all the
1075 placeholders (first) before turning on the readonly flag, because
1076 Storable always pre-splits the hash. */
1077 hv_clear_placeholders(hv);
1081 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1082 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1088 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1093 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1094 if (oldsize >= 64) {
1095 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1096 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1099 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1103 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1104 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1105 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1108 for (i=0; i<oldsize; i++,aep++) {
1109 int left_length = 0;
1110 int right_length = 0;
1112 if (!*aep) /* non-existent */
1115 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1116 if ((HeHASH(entry) & newsize) != (U32)i) {
1117 *oentry = HeNEXT(entry);
1118 HeNEXT(entry) = *bep;
1120 xhv->xhv_fill++; /* HvFILL(hv)++ */
1126 oentry = &HeNEXT(entry);
1130 if (!*aep) /* everything moved */
1131 xhv->xhv_fill--; /* HvFILL(hv)-- */
1132 /* I think we don't actually need to keep track of the longest length,
1133 merely flag if anything is too long. But for the moment while
1134 developing this code I'll track it. */
1135 if (left_length > longest_chain)
1136 longest_chain = left_length;
1137 if (right_length > longest_chain)
1138 longest_chain = right_length;
1142 /* Pick your policy for "hashing isn't working" here: */
1143 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1148 if (hv == PL_strtab) {
1149 /* Urg. Someone is doing something nasty to the string table.
1154 /* Awooga. Awooga. Pathological data. */
1155 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1156 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1159 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1160 was_shared = HvSHAREKEYS(hv);
1163 HvSHAREKEYS_off(hv);
1166 aep = (HE **) xhv->xhv_array;
1168 for (i=0; i<newsize; i++,aep++) {
1171 /* We're going to trash this HE's next pointer when we chain it
1172 into the new hash below, so store where we go next. */
1173 HE *next = HeNEXT(entry);
1177 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1182 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1183 hash, HeKFLAGS(entry));
1184 unshare_hek (HeKEY_hek(entry));
1185 HeKEY_hek(entry) = new_hek;
1187 /* Not shared, so simply write the new hash in. */
1188 HeHASH(entry) = hash;
1190 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1191 HEK_REHASH_on(HeKEY_hek(entry));
1192 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1194 /* Copy oentry to the correct new chain. */
1195 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1197 xhv->xhv_fill++; /* HvFILL(hv)++ */
1198 HeNEXT(entry) = *bep;
1204 Safefree (xhv->xhv_array);
1205 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1209 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1211 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1212 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1213 register I32 newsize;
1219 register HE **oentry;
1221 newsize = (I32) newmax; /* possible truncation here */
1222 if (newsize != newmax || newmax <= oldsize)
1224 while ((newsize & (1 + ~newsize)) != newsize) {
1225 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1227 if (newsize < newmax)
1229 if (newsize < newmax)
1230 return; /* overflow detection */
1232 a = xhv->xhv_array; /* HvARRAY(hv) */
1235 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1236 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1242 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1247 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1248 if (oldsize >= 64) {
1249 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1250 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1253 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1256 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1259 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1261 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1262 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1263 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1267 for (i=0; i<oldsize; i++,aep++) {
1268 if (!*aep) /* non-existent */
1270 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1271 if ((j = (HeHASH(entry) & newsize)) != i) {
1273 *oentry = HeNEXT(entry);
1274 if (!(HeNEXT(entry) = aep[j]))
1275 xhv->xhv_fill++; /* HvFILL(hv)++ */
1280 oentry = &HeNEXT(entry);
1282 if (!*aep) /* everything moved */
1283 xhv->xhv_fill--; /* HvFILL(hv)-- */
1290 Creates a new HV. The reference count is set to 1.
1299 register XPVHV* xhv;
1301 hv = (HV*)NEWSV(502,0);
1302 sv_upgrade((SV *)hv, SVt_PVHV);
1303 xhv = (XPVHV*)SvANY(hv);
1306 #ifndef NODEFAULT_SHAREKEYS
1307 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1310 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1311 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1312 xhv->xhv_pmroot = 0; /* HvPMROOT(hv) = 0 */
1313 (void)hv_iterinit(hv); /* so each() will start off right */
1318 Perl_newHVhv(pTHX_ HV *ohv)
1321 STRLEN hv_max, hv_fill;
1323 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1325 hv_max = HvMAX(ohv);
1327 if (!SvMAGICAL((SV *)ohv)) {
1328 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1330 bool shared = !!HvSHAREKEYS(ohv);
1331 HE **ents, **oents = (HE **)HvARRAY(ohv);
1333 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1336 /* In each bucket... */
1337 for (i = 0; i <= hv_max; i++) {
1338 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1345 /* Copy the linked list of entries. */
1346 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1347 U32 hash = HeHASH(oent);
1348 char *key = HeKEY(oent);
1349 STRLEN len = HeKLEN(oent);
1350 int flags = HeKFLAGS(oent);
1353 HeVAL(ent) = newSVsv(HeVAL(oent));
1355 = shared ? share_hek_flags(key, len, hash, flags)
1356 : save_hek_flags(key, len, hash, flags);
1367 HvFILL(hv) = hv_fill;
1368 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1372 /* Iterate over ohv, copying keys and values one at a time. */
1374 I32 riter = HvRITER(ohv);
1375 HE *eiter = HvEITER(ohv);
1377 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1378 while (hv_max && hv_max + 1 >= hv_fill * 2)
1379 hv_max = hv_max / 2;
1383 while ((entry = hv_iternext_flags(ohv, 0))) {
1384 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1385 newSVsv(HeVAL(entry)), HeHASH(entry),
1388 HvRITER(ohv) = riter;
1389 HvEITER(ohv) = eiter;
1396 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1403 if (val && isGV(val) && GvCVu(val) && HvNAME(hv))
1404 PL_sub_generation++; /* may be deletion of method from stash */
1406 if (HeKLEN(entry) == HEf_SVKEY) {
1407 SvREFCNT_dec(HeKEY_sv(entry));
1408 Safefree(HeKEY_hek(entry));
1410 else if (HvSHAREKEYS(hv))
1411 unshare_hek(HeKEY_hek(entry));
1413 Safefree(HeKEY_hek(entry));
1418 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1422 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME(hv))
1423 PL_sub_generation++; /* may be deletion of method from stash */
1424 sv_2mortal(HeVAL(entry)); /* free between statements */
1425 if (HeKLEN(entry) == HEf_SVKEY) {
1426 sv_2mortal(HeKEY_sv(entry));
1427 Safefree(HeKEY_hek(entry));
1429 else if (HvSHAREKEYS(hv))
1430 unshare_hek(HeKEY_hek(entry));
1432 Safefree(HeKEY_hek(entry));
1437 =for apidoc hv_clear
1439 Clears a hash, making it empty.
1445 Perl_hv_clear(pTHX_ HV *hv)
1448 register XPVHV* xhv;
1452 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1454 xhv = (XPVHV*)SvANY(hv);
1456 if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
1457 /* restricted hash: convert all keys to placeholders */
1460 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1461 entry = ((HE**)xhv->xhv_array)[i];
1462 for (; entry; entry = HeNEXT(entry)) {
1463 /* not already placeholder */
1464 if (HeVAL(entry) != &PL_sv_placeholder) {
1465 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1466 SV* keysv = hv_iterkeysv(entry);
1468 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1471 SvREFCNT_dec(HeVAL(entry));
1472 HeVAL(entry) = &PL_sv_placeholder;
1473 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1481 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1482 if (xhv->xhv_array /* HvARRAY(hv) */)
1483 (void)memzero(xhv->xhv_array /* HvARRAY(hv) */,
1484 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1489 HvHASKFLAGS_off(hv);
1496 =for apidoc hv_clear_placeholders
1498 Clears any placeholders from a hash. If a restricted hash has any of its keys
1499 marked as readonly and the key is subsequently deleted, the key is not actually
1500 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1501 it so it will be ignored by future operations such as iterating over the hash,
1502 but will still allow the hash to have a value reassigned to the key at some
1503 future point. This function clears any such placeholder keys from the hash.
1504 See Hash::Util::lock_keys() for an example of its use.
1510 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1513 I32 items = (I32)HvPLACEHOLDERS(hv);
1520 /* Loop down the linked list heads */
1522 HE **oentry = &(HvARRAY(hv))[i];
1523 HE *entry = *oentry;
1528 for (; entry; entry = *oentry) {
1529 if (HeVAL(entry) == &PL_sv_placeholder) {
1530 *oentry = HeNEXT(entry);
1531 if (first && !*oentry)
1532 HvFILL(hv)--; /* This linked list is now empty. */
1536 hv_free_ent(hv, entry);
1540 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS(hv);
1541 if (HvKEYS(hv) == 0)
1542 HvHASKFLAGS_off(hv);
1543 HvPLACEHOLDERS(hv) = 0;
1547 oentry = &HeNEXT(entry);
1552 /* You can't get here, hence assertion should always fail. */
1553 assert (items == 0);
1558 S_hfreeentries(pTHX_ HV *hv)
1560 register HE **array;
1562 register HE *oentry = Null(HE*);
1573 array = HvARRAY(hv);
1574 /* make everyone else think the array is empty, so that the destructors
1575 * called for freed entries can't recusively mess with us */
1576 HvARRAY(hv) = Null(HE**);
1578 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1584 entry = HeNEXT(entry);
1585 hv_free_ent(hv, oentry);
1590 entry = array[riter];
1593 HvARRAY(hv) = array;
1594 (void)hv_iterinit(hv);
1598 =for apidoc hv_undef
1606 Perl_hv_undef(pTHX_ HV *hv)
1608 register XPVHV* xhv;
1611 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1612 xhv = (XPVHV*)SvANY(hv);
1614 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1617 hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD);
1618 Safefree(HvNAME(hv));
1621 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1622 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
1623 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1630 =for apidoc hv_iterinit
1632 Prepares a starting point to traverse a hash table. Returns the number of
1633 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1634 currently only meaningful for hashes without tie magic.
1636 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1637 hash buckets that happen to be in use. If you still need that esoteric
1638 value, you can get it through the macro C<HvFILL(tb)>.
1645 Perl_hv_iterinit(pTHX_ HV *hv)
1647 register XPVHV* xhv;
1651 Perl_croak(aTHX_ "Bad hash");
1652 xhv = (XPVHV*)SvANY(hv);
1653 entry = xhv->xhv_eiter; /* HvEITER(hv) */
1654 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1656 hv_free_ent(hv, entry);
1658 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1659 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1660 /* used to be xhv->xhv_fill before 5.004_65 */
1661 return XHvTOTALKEYS(xhv);
1664 =for apidoc hv_iternext
1666 Returns entries from a hash iterator. See C<hv_iterinit>.
1668 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1669 iterator currently points to, without losing your place or invalidating your
1670 iterator. Note that in this case the current entry is deleted from the hash
1671 with your iterator holding the last reference to it. Your iterator is flagged
1672 to free the entry on the next call to C<hv_iternext>, so you must not discard
1673 your iterator immediately else the entry will leak - call C<hv_iternext> to
1674 trigger the resource deallocation.
1680 Perl_hv_iternext(pTHX_ HV *hv)
1682 return hv_iternext_flags(hv, 0);
1686 =for apidoc hv_iternext_flags
1688 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1689 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1690 set the placeholders keys (for restricted hashes) will be returned in addition
1691 to normal keys. By default placeholders are automatically skipped over.
1692 Currently a placeholder is implemented with a value that is
1693 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1694 restricted hashes may change, and the implementation currently is
1695 insufficiently abstracted for any change to be tidy.
1701 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1704 register XPVHV* xhv;
1710 Perl_croak(aTHX_ "Bad hash");
1711 xhv = (XPVHV*)SvANY(hv);
1712 oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */
1714 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1715 SV *key = sv_newmortal();
1717 sv_setsv(key, HeSVKEY_force(entry));
1718 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1724 /* one HE per MAGICAL hash */
1725 xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1727 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1729 HeKEY_hek(entry) = hek;
1730 HeKLEN(entry) = HEf_SVKEY;
1732 magic_nextpack((SV*) hv,mg,key);
1734 /* force key to stay around until next time */
1735 HeSVKEY_set(entry, SvREFCNT_inc(key));
1736 return entry; /* beware, hent_val is not set */
1739 SvREFCNT_dec(HeVAL(entry));
1740 Safefree(HeKEY_hek(entry));
1742 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1745 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1746 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1750 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1751 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
1752 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1754 /* At start of hash, entry is NULL. */
1757 entry = HeNEXT(entry);
1758 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1760 * Skip past any placeholders -- don't want to include them in
1763 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1764 entry = HeNEXT(entry);
1769 /* OK. Come to the end of the current list. Grab the next one. */
1771 xhv->xhv_riter++; /* HvRITER(hv)++ */
1772 if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1773 /* There is no next one. End of the hash. */
1774 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1777 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
1778 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
1780 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1781 /* If we have an entry, but it's a placeholder, don't count it.
1783 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1784 entry = HeNEXT(entry);
1786 /* Will loop again if this linked list starts NULL
1787 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1788 or if we run through it and find only placeholders. */
1791 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1793 hv_free_ent(hv, oldentry);
1796 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1797 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1799 xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */
1804 =for apidoc hv_iterkey
1806 Returns the key from the current position of the hash iterator. See
1813 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1815 if (HeKLEN(entry) == HEf_SVKEY) {
1817 char *p = SvPV(HeKEY_sv(entry), len);
1822 *retlen = HeKLEN(entry);
1823 return HeKEY(entry);
1827 /* unlike hv_iterval(), this always returns a mortal copy of the key */
1829 =for apidoc hv_iterkeysv
1831 Returns the key as an C<SV*> from the current position of the hash
1832 iterator. The return value will always be a mortal copy of the key. Also
1839 Perl_hv_iterkeysv(pTHX_ register HE *entry)
1841 if (HeKLEN(entry) != HEf_SVKEY) {
1842 HEK *hek = HeKEY_hek(entry);
1843 int flags = HEK_FLAGS(hek);
1846 if (flags & HVhek_WASUTF8) {
1848 Andreas would like keys he put in as utf8 to come back as utf8
1850 STRLEN utf8_len = HEK_LEN(hek);
1851 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
1853 sv = newSVpvn ((char*)as_utf8, utf8_len);
1855 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
1856 } else if (flags & HVhek_REHASH) {
1857 /* We don't have a pointer to the hv, so we have to replicate the
1858 flag into every HEK. This hv is using custom a hasing
1859 algorithm. Hence we can't return a shared string scalar, as
1860 that would contain the (wrong) hash value, and might get passed
1861 into an hv routine with a regular hash */
1863 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
1867 sv = newSVpvn_share(HEK_KEY(hek),
1868 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
1871 return sv_2mortal(sv);
1873 return sv_mortalcopy(HeKEY_sv(entry));
1877 =for apidoc hv_iterval
1879 Returns the value from the current position of the hash iterator. See
1886 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
1888 if (SvRMAGICAL(hv)) {
1889 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
1890 SV* sv = sv_newmortal();
1891 if (HeKLEN(entry) == HEf_SVKEY)
1892 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
1893 else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
1897 return HeVAL(entry);
1901 =for apidoc hv_iternextsv
1903 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
1910 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
1913 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
1915 *key = hv_iterkey(he, retlen);
1916 return hv_iterval(hv, he);
1920 =for apidoc hv_magic
1922 Adds magic to a hash. See C<sv_magic>.
1928 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
1930 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
1933 #if 0 /* use the macro from hv.h instead */
1936 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
1938 return HEK_KEY(share_hek(sv, len, hash));
1943 /* possibly free a shared string if no one has access to it
1944 * len and hash must both be valid for str.
1947 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
1949 unshare_hek_or_pvn (NULL, str, len, hash);
1954 Perl_unshare_hek(pTHX_ HEK *hek)
1956 unshare_hek_or_pvn(hek, NULL, 0, 0);
1959 /* possibly free a shared string if no one has access to it
1960 hek if non-NULL takes priority over the other 3, else str, len and hash
1961 are used. If so, len and hash must both be valid for str.
1964 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
1966 register XPVHV* xhv;
1968 register HE **oentry;
1971 bool is_utf8 = FALSE;
1973 const char *save = str;
1976 hash = HEK_HASH(hek);
1977 } else if (len < 0) {
1978 STRLEN tmplen = -len;
1980 /* See the note in hv_fetch(). --jhi */
1981 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
1984 k_flags = HVhek_UTF8;
1986 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1989 /* what follows is the moral equivalent of:
1990 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
1991 if (--*Svp == Nullsv)
1992 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
1994 xhv = (XPVHV*)SvANY(PL_strtab);
1995 /* assert(xhv_array != 0) */
1997 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1998 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2000 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2001 if (HeKEY_hek(entry) != hek)
2007 const int flags_masked = k_flags & HVhek_MASK;
2008 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2009 if (HeHASH(entry) != hash) /* strings can't be equal */
2011 if (HeKLEN(entry) != len)
2013 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2015 if (HeKFLAGS(entry) != flags_masked)
2023 if (--HeVAL(entry) == Nullsv) {
2024 *oentry = HeNEXT(entry);
2026 xhv->xhv_fill--; /* HvFILL(hv)-- */
2027 Safefree(HeKEY_hek(entry));
2029 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2033 UNLOCK_STRTAB_MUTEX;
2034 if (!found && ckWARN_d(WARN_INTERNAL))
2035 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2036 "Attempt to free non-existent shared string '%s'%s"
2038 hek ? HEK_KEY(hek) : str,
2039 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2040 if (k_flags & HVhek_FREEKEY)
2044 /* get a (constant) string ptr from the global string table
2045 * string will get added if it is not already there.
2046 * len and hash must both be valid for str.
2049 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2051 bool is_utf8 = FALSE;
2053 const char *save = str;
2056 STRLEN tmplen = -len;
2058 /* See the note in hv_fetch(). --jhi */
2059 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2061 /* If we were able to downgrade here, then than means that we were passed
2062 in a key which only had chars 0-255, but was utf8 encoded. */
2065 /* If we found we were able to downgrade the string to bytes, then
2066 we should flag that it needs upgrading on keys or each. Also flag
2067 that we need share_hek_flags to free the string. */
2069 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2072 return share_hek_flags (str, len, hash, flags);
2076 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2078 register XPVHV* xhv;
2080 register HE **oentry;
2083 const int flags_masked = flags & HVhek_MASK;
2085 /* what follows is the moral equivalent of:
2087 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2088 hv_store(PL_strtab, str, len, Nullsv, hash);
2090 Can't rehash the shared string table, so not sure if it's worth
2091 counting the number of entries in the linked list
2093 xhv = (XPVHV*)SvANY(PL_strtab);
2094 /* assert(xhv_array != 0) */
2096 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2097 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2098 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2099 if (HeHASH(entry) != hash) /* strings can't be equal */
2101 if (HeKLEN(entry) != len)
2103 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2105 if (HeKFLAGS(entry) != flags_masked)
2112 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2113 HeVAL(entry) = Nullsv;
2114 HeNEXT(entry) = *oentry;
2116 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2117 if (i) { /* initial entry? */
2118 xhv->xhv_fill++; /* HvFILL(hv)++ */
2119 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2124 ++HeVAL(entry); /* use value slot as REFCNT */
2125 UNLOCK_STRTAB_MUTEX;
2127 if (flags & HVhek_FREEKEY)
2130 return HeKEY_hek(entry);
2135 =for apidoc hv_assert
2137 Check that a hash is in an internally consistent state.
2143 Perl_hv_assert(pTHX_ HV *hv)
2148 int placeholders = 0;
2151 I32 riter = HvRITER(hv);
2152 HE *eiter = HvEITER(hv);
2154 (void)hv_iterinit(hv);
2156 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2157 /* sanity check the values */
2158 if (HeVAL(entry) == &PL_sv_placeholder) {
2163 /* sanity check the keys */
2164 if (HeSVKEY(entry)) {
2165 /* Don't know what to check on SV keys. */
2166 } else if (HeKUTF8(entry)) {
2168 if (HeKWASUTF8(entry)) {
2169 PerlIO_printf(Perl_debug_log,
2170 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2171 (int) HeKLEN(entry), HeKEY(entry));
2174 } else if (HeKWASUTF8(entry)) {
2178 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2179 if (HvUSEDKEYS(hv) != real) {
2180 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2181 (int) real, (int) HvUSEDKEYS(hv));
2184 if (HvPLACEHOLDERS(hv) != placeholders) {
2185 PerlIO_printf(Perl_debug_log,
2186 "Count %d placeholder(s), but hash reports %d\n",
2187 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2191 if (withflags && ! HvHASKFLAGS(hv)) {
2192 PerlIO_printf(Perl_debug_log,
2193 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2200 HvRITER(hv) = riter; /* Restore hash iterator state */
2201 HvEITER(hv) = eiter;
2206 * c-indentation-style: bsd
2208 * indent-tabs-mode: t
2211 * vim: shiftwidth=4: