3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
41 New(54, he, PERL_ARENA_SIZE/sizeof(HE), HE);
42 HeNEXT(he) = PL_he_arenaroot;
45 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
48 HeNEXT(he) = (HE*)(he + 1);
62 PL_he_root = HeNEXT(he);
71 HeNEXT(p) = (HE*)PL_he_root;
78 #define new_HE() (HE*)safemalloc(sizeof(HE))
79 #define del_HE(p) safefree((char*)p)
83 #define new_HE() new_he()
84 #define del_HE(p) del_he(p)
89 S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
91 const int flags_masked = flags & HVhek_MASK;
95 New(54, k, HEK_BASESIZE + len + 2, char);
97 Copy(str, HEK_KEY(hek), len, char);
98 HEK_KEY(hek)[len] = 0;
100 HEK_HASH(hek) = hash;
101 HEK_FLAGS(hek) = (unsigned char)flags_masked;
103 if (flags & HVhek_FREEKEY)
108 /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
112 Perl_free_tied_hv_pool(pTHX)
115 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
122 PL_hv_fetch_ent_mh = Nullhe;
125 #if defined(USE_ITHREADS)
127 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
133 /* look for it in the table first */
134 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
138 /* create anew and remember what it is */
140 ptr_table_store(PL_ptr_table, e, ret);
142 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
143 if (HeKLEN(e) == HEf_SVKEY) {
145 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
146 HeKEY_hek(ret) = (HEK*)k;
147 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
150 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
153 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
155 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
158 #endif /* USE_ITHREADS */
161 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
164 SV *sv = sv_newmortal();
165 if (!(flags & HVhek_FREEKEY)) {
166 sv_setpvn(sv, key, klen);
169 /* Need to free saved eventually assign to mortal SV */
170 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
171 sv_usepvn(sv, (char *) key, klen);
173 if (flags & HVhek_UTF8) {
176 Perl_croak(aTHX_ msg, sv);
179 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
182 #define HV_FETCH_ISSTORE 0x01
183 #define HV_FETCH_ISEXISTS 0x02
184 #define HV_FETCH_LVALUE 0x04
185 #define HV_FETCH_JUST_SV 0x08
190 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
191 the length of the key. The C<hash> parameter is the precomputed hash
192 value; if it is zero then Perl will compute it. The return value will be
193 NULL if the operation failed or if the value did not need to be actually
194 stored within the hash (as in the case of tied hashes). Otherwise it can
195 be dereferenced to get the original C<SV*>. Note that the caller is
196 responsible for suitably incrementing the reference count of C<val> before
197 the call, and decrementing it if the function returned NULL. Effectively
198 a successful hv_store takes ownership of one reference to C<val>. This is
199 usually what you want; a newly created SV has a reference count of one, so
200 if all your code does is create SVs then store them in a hash, hv_store
201 will own the only reference to the new SV, and your code doesn't need to do
202 anything further to tidy up. hv_store is not implemented as a call to
203 hv_store_ent, and does not create a temporary SV for the key, so if your
204 key data is not already in SV form then use hv_store in preference to
207 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
208 information on how to use this function on tied hashes.
214 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
227 hek = hv_fetch_common (hv, NULL, key, klen, flags,
228 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
229 return hek ? &HeVAL(hek) : NULL;
233 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
234 register U32 hash, int flags)
236 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
237 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
238 return hek ? &HeVAL(hek) : NULL;
242 =for apidoc hv_store_ent
244 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
245 parameter is the precomputed hash value; if it is zero then Perl will
246 compute it. The return value is the new hash entry so created. It will be
247 NULL if the operation failed or if the value did not need to be actually
248 stored within the hash (as in the case of tied hashes). Otherwise the
249 contents of the return value can be accessed using the C<He?> macros
250 described here. Note that the caller is responsible for suitably
251 incrementing the reference count of C<val> before the call, and
252 decrementing it if the function returned NULL. Effectively a successful
253 hv_store_ent takes ownership of one reference to C<val>. This is
254 usually what you want; a newly created SV has a reference count of one, so
255 if all your code does is create SVs then store them in a hash, hv_store
256 will own the only reference to the new SV, and your code doesn't need to do
257 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
258 unlike C<val> it does not take ownership of it, so maintaining the correct
259 reference count on C<key> is entirely the caller's responsibility. hv_store
260 is not implemented as a call to hv_store_ent, and does not create a temporary
261 SV for the key, so if your key data is not already in SV form then use
262 hv_store in preference to hv_store_ent.
264 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
265 information on how to use this function on tied hashes.
271 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
273 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
277 =for apidoc hv_exists
279 Returns a boolean indicating whether the specified hash key exists. The
280 C<klen> is the length of the key.
286 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
298 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
305 Returns the SV which corresponds to the specified key in the hash. The
306 C<klen> is the length of the key. If C<lval> is set then the fetch will be
307 part of a store. Check that the return value is non-null before
308 dereferencing it to an C<SV*>.
310 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
311 information on how to use this function on tied hashes.
317 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
330 hek = hv_fetch_common (hv, NULL, key, klen, flags,
331 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
333 return hek ? &HeVAL(hek) : NULL;
337 =for apidoc hv_exists_ent
339 Returns a boolean indicating whether the specified hash key exists. C<hash>
340 can be a valid precomputed hash value, or 0 to ask for it to be
347 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
349 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
353 /* returns an HE * structure with the all fields set */
354 /* note that hent_val will be a mortal sv for MAGICAL hashes */
356 =for apidoc hv_fetch_ent
358 Returns the hash entry which corresponds to the specified key in the hash.
359 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
360 if you want the function to compute it. IF C<lval> is set then the fetch
361 will be part of a store. Make sure the return value is non-null before
362 accessing it. The return value when C<tb> is a tied hash is a pointer to a
363 static location, so be sure to make a copy of the structure if you need to
366 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
367 information on how to use this function on tied hashes.
373 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
375 return hv_fetch_common(hv, keysv, NULL, 0, 0,
376 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
380 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
381 int flags, int action, SV *val, register U32 hash)
396 if (flags & HVhek_FREEKEY)
398 key = SvPV(keysv, klen);
400 is_utf8 = (SvUTF8(keysv) != 0);
402 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
405 xhv = (XPVHV*)SvANY(hv);
407 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
409 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
412 /* XXX should be able to skimp on the HE/HEK here when
413 HV_FETCH_JUST_SV is true. */
416 keysv = newSVpvn(key, klen);
421 keysv = newSVsv(keysv);
423 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
425 /* grab a fake HE/HEK pair from the pool or make a new one */
426 entry = PL_hv_fetch_ent_mh;
428 PL_hv_fetch_ent_mh = HeNEXT(entry);
432 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
433 HeKEY_hek(entry) = (HEK*)k;
435 HeNEXT(entry) = Nullhe;
436 HeSVKEY_set(entry, keysv);
438 sv_upgrade(sv, SVt_PVLV);
440 /* so we can free entry when freeing sv */
441 LvTARG(sv) = (SV*)entry;
443 /* XXX remove at some point? */
444 if (flags & HVhek_FREEKEY)
449 #ifdef ENV_IS_CASELESS
450 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
452 for (i = 0; i < klen; ++i)
453 if (isLOWER(key[i])) {
454 /* Would be nice if we had a routine to do the
455 copy and upercase in a single pass through. */
456 const char *nkey = strupr(savepvn(key,klen));
457 /* Note that this fetch is for nkey (the uppercased
458 key) whereas the store is for key (the original) */
459 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
460 HVhek_FREEKEY, /* free nkey */
461 0 /* non-LVAL fetch */,
462 Nullsv /* no value */,
463 0 /* compute hash */);
464 if (!entry && (action & HV_FETCH_LVALUE)) {
465 /* This call will free key if necessary.
466 Do it this way to encourage compiler to tail
468 entry = hv_fetch_common(hv, keysv, key, klen,
469 flags, HV_FETCH_ISSTORE,
472 if (flags & HVhek_FREEKEY)
480 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
481 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
483 /* I don't understand why hv_exists_ent has svret and sv,
484 whereas hv_exists only had one. */
485 svret = sv_newmortal();
488 if (keysv || is_utf8) {
490 keysv = newSVpvn(key, klen);
493 keysv = newSVsv(keysv);
495 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
497 mg_copy((SV*)hv, sv, key, klen);
499 if (flags & HVhek_FREEKEY)
501 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
502 /* This cast somewhat evil, but I'm merely using NULL/
503 not NULL to return the boolean exists.
504 And I know hv is not NULL. */
505 return SvTRUE(svret) ? (HE *)hv : NULL;
507 #ifdef ENV_IS_CASELESS
508 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
509 /* XXX This code isn't UTF8 clean. */
510 const char *keysave = key;
511 /* Will need to free this, so set FREEKEY flag. */
512 key = savepvn(key,klen);
513 key = (const char*)strupr((char*)key);
518 if (flags & HVhek_FREEKEY) {
521 flags |= HVhek_FREEKEY;
525 else if (action & HV_FETCH_ISSTORE) {
528 hv_magic_check (hv, &needs_copy, &needs_store);
530 const bool save_taint = PL_tainted;
531 if (keysv || is_utf8) {
533 keysv = newSVpvn(key, klen);
537 PL_tainted = SvTAINTED(keysv);
538 keysv = sv_2mortal(newSVsv(keysv));
539 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
541 mg_copy((SV*)hv, val, key, klen);
544 TAINT_IF(save_taint);
545 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) {
546 if (flags & HVhek_FREEKEY)
550 #ifdef ENV_IS_CASELESS
551 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
552 /* XXX This code isn't UTF8 clean. */
553 const char *keysave = key;
554 /* Will need to free this, so set FREEKEY flag. */
555 key = savepvn(key,klen);
556 key = (const char*)strupr((char*)key);
561 if (flags & HVhek_FREEKEY) {
564 flags |= HVhek_FREEKEY;
571 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
572 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
573 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
574 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
577 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
578 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
580 #ifdef DYNAMIC_ENV_FETCH
581 else if (action & HV_FETCH_ISEXISTS) {
582 /* for an %ENV exists, if we do an insert it's by a recursive
583 store call, so avoid creating HvARRAY(hv) right now. */
587 /* XXX remove at some point? */
588 if (flags & HVhek_FREEKEY)
596 const char *keysave = key;
597 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
601 flags &= ~HVhek_UTF8;
602 if (key != keysave) {
603 if (flags & HVhek_FREEKEY)
605 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
610 PERL_HASH_INTERNAL(hash, key, klen);
611 /* We don't have a pointer to the hv, so we have to replicate the
612 flag into every HEK, so that hv_iterkeysv can see it. */
613 /* And yes, you do need this even though you are not "storing" because
614 you can flip the flags below if doing an lval lookup. (And that
615 was put in to give the semantics Andreas was expecting.) */
616 flags |= HVhek_REHASH;
618 if (keysv && (SvIsCOW_shared_hash(keysv))) {
621 PERL_HASH(hash, key, klen);
625 masked_flags = (flags & HVhek_MASK);
628 #ifdef DYNAMIC_ENV_FETCH
629 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
633 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
634 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
636 for (; entry; ++n_links, entry = HeNEXT(entry)) {
637 if (HeHASH(entry) != hash) /* strings can't be equal */
639 if (HeKLEN(entry) != (I32)klen)
641 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
643 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
646 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
647 if (HeKFLAGS(entry) != masked_flags) {
648 /* We match if HVhek_UTF8 bit in our flags and hash key's
649 match. But if entry was set previously with HVhek_WASUTF8
650 and key now doesn't (or vice versa) then we should change
651 the key's flag, as this is assignment. */
652 if (HvSHAREKEYS(hv)) {
653 /* Need to swap the key we have for a key with the flags we
654 need. As keys are shared we can't just write to the
655 flag, so we share the new one, unshare the old one. */
656 HEK *new_hek = share_hek_flags(key, klen, hash,
658 unshare_hek (HeKEY_hek(entry));
659 HeKEY_hek(entry) = new_hek;
662 HeKFLAGS(entry) = masked_flags;
663 if (masked_flags & HVhek_ENABLEHVKFLAGS)
666 if (HeVAL(entry) == &PL_sv_placeholder) {
667 /* yes, can store into placeholder slot */
668 if (action & HV_FETCH_LVALUE) {
670 /* This preserves behaviour with the old hv_fetch
671 implementation which at this point would bail out
672 with a break; (at "if we find a placeholder, we
673 pretend we haven't found anything")
675 That break mean that if a placeholder were found, it
676 caused a call into hv_store, which in turn would
677 check magic, and if there is no magic end up pretty
678 much back at this point (in hv_store's code). */
681 /* LVAL fetch which actaully needs a store. */
683 HvPLACEHOLDERS(hv)--;
686 if (val != &PL_sv_placeholder)
687 HvPLACEHOLDERS(hv)--;
690 } else if (action & HV_FETCH_ISSTORE) {
691 SvREFCNT_dec(HeVAL(entry));
694 } else if (HeVAL(entry) == &PL_sv_placeholder) {
695 /* if we find a placeholder, we pretend we haven't found
699 if (flags & HVhek_FREEKEY)
703 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
704 if (!(action & HV_FETCH_ISSTORE)
705 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
707 char *env = PerlEnv_ENVgetenv_len(key,&len);
709 sv = newSVpvn(env,len);
711 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
717 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
718 S_hv_notallowed(aTHX_ flags, key, klen,
719 "Attempt to access disallowed key '%"SVf"' in"
720 " a restricted hash");
722 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
723 /* Not doing some form of store, so return failure. */
724 if (flags & HVhek_FREEKEY)
728 if (action & HV_FETCH_LVALUE) {
731 /* At this point the old hv_fetch code would call to hv_store,
732 which in turn might do some tied magic. So we need to make that
733 magic check happen. */
734 /* gonna assign to this, so it better be there */
735 return hv_fetch_common(hv, keysv, key, klen, flags,
736 HV_FETCH_ISSTORE, val, hash);
737 /* XXX Surely that could leak if the fetch-was-store fails?
738 Just like the hv_fetch. */
742 /* Welcome to hv_store... */
744 if (!xhv->xhv_array) {
745 /* Not sure if we can get here. I think the only case of oentry being
746 NULL is for %ENV with dynamic env fetch. But that should disappear
747 with magic in the previous code. */
748 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
749 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
753 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
756 /* share_hek_flags will do the free for us. This might be considered
759 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
760 else /* gotta do the real thing */
761 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
763 HeNEXT(entry) = *oentry;
766 if (val == &PL_sv_placeholder)
767 HvPLACEHOLDERS(hv)++;
768 if (masked_flags & HVhek_ENABLEHVKFLAGS)
771 xhv->xhv_keys++; /* HvKEYS(hv)++ */
772 if (!n_links) { /* initial entry? */
773 xhv->xhv_fill++; /* HvFILL(hv)++ */
774 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
775 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
776 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
777 splits on a rehashed hash, as we're not going to split it again,
778 and if someone is lucky (evil) enough to get all the keys in one
779 list they could exhaust our memory as we repeatedly double the
780 number of buckets on every entry. Linear search feels a less worse
789 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
791 const MAGIC *mg = SvMAGIC(hv);
795 if (isUPPER(mg->mg_type)) {
797 switch (mg->mg_type) {
798 case PERL_MAGIC_tied:
800 *needs_store = FALSE;
803 mg = mg->mg_moremagic;
808 =for apidoc hv_scalar
810 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
816 Perl_hv_scalar(pTHX_ HV *hv)
821 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
822 sv = magic_scalarpack(hv, mg);
828 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
829 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
837 =for apidoc hv_delete
839 Deletes a key/value pair in the hash. The value SV is removed from the
840 hash and returned to the caller. The C<klen> is the length of the key.
841 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
848 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
855 k_flags |= HVhek_UTF8;
859 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
863 =for apidoc hv_delete_ent
865 Deletes a key/value pair in the hash. The value SV is removed from the
866 hash and returned to the caller. The C<flags> value will normally be zero;
867 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
868 precomputed hash value, or 0 to ask for it to be computed.
874 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
876 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
880 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
881 int k_flags, I32 d_flags, U32 hash)
887 register HE **oentry;
896 if (k_flags & HVhek_FREEKEY)
898 key = SvPV(keysv, klen);
900 is_utf8 = (SvUTF8(keysv) != 0);
902 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
905 if (SvRMAGICAL(hv)) {
908 hv_magic_check (hv, &needs_copy, &needs_store);
911 entry = hv_fetch_common(hv, keysv, key, klen,
912 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
914 sv = entry ? HeVAL(entry) : NULL;
920 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
921 /* No longer an element */
922 sv_unmagic(sv, PERL_MAGIC_tiedelem);
925 return Nullsv; /* element cannot be deleted */
927 #ifdef ENV_IS_CASELESS
928 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
929 /* XXX This code isn't UTF8 clean. */
930 keysv = sv_2mortal(newSVpvn(key,klen));
931 if (k_flags & HVhek_FREEKEY) {
934 key = strupr(SvPVX(keysv));
943 xhv = (XPVHV*)SvANY(hv);
944 if (!xhv->xhv_array /* !HvARRAY(hv) */)
948 const char *keysave = key;
949 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
952 k_flags |= HVhek_UTF8;
954 k_flags &= ~HVhek_UTF8;
955 if (key != keysave) {
956 if (k_flags & HVhek_FREEKEY) {
957 /* This shouldn't happen if our caller does what we expect,
958 but strictly the API allows it. */
961 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
963 HvHASKFLAGS_on((SV*)hv);
967 PERL_HASH_INTERNAL(hash, key, klen);
969 if (keysv && (SvIsCOW_shared_hash(keysv))) {
972 PERL_HASH(hash, key, klen);
976 masked_flags = (k_flags & HVhek_MASK);
978 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
979 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
982 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
983 if (HeHASH(entry) != hash) /* strings can't be equal */
985 if (HeKLEN(entry) != (I32)klen)
987 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
989 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
992 /* if placeholder is here, it's already been deleted.... */
993 if (HeVAL(entry) == &PL_sv_placeholder)
995 if (k_flags & HVhek_FREEKEY)
999 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1000 S_hv_notallowed(aTHX_ k_flags, key, klen,
1001 "Attempt to delete readonly key '%"SVf"' from"
1002 " a restricted hash");
1004 if (k_flags & HVhek_FREEKEY)
1007 if (d_flags & G_DISCARD)
1010 sv = sv_2mortal(HeVAL(entry));
1011 HeVAL(entry) = &PL_sv_placeholder;
1015 * If a restricted hash, rather than really deleting the entry, put
1016 * a placeholder there. This marks the key as being "approved", so
1017 * we can still access via not-really-existing key without raising
1020 if (SvREADONLY(hv)) {
1021 SvREFCNT_dec(HeVAL(entry));
1022 HeVAL(entry) = &PL_sv_placeholder;
1023 /* We'll be saving this slot, so the number of allocated keys
1024 * doesn't go down, but the number placeholders goes up */
1025 HvPLACEHOLDERS(hv)++;
1027 *oentry = HeNEXT(entry);
1029 xhv->xhv_fill--; /* HvFILL(hv)-- */
1030 if (xhv->xhv_aux && entry
1031 == ((struct xpvhv_aux *)xhv->xhv_aux)->xhv_eiter /* HvEITER(hv) */)
1034 hv_free_ent(hv, entry);
1035 xhv->xhv_keys--; /* HvKEYS(hv)-- */
1036 if (xhv->xhv_keys == 0)
1037 HvHASKFLAGS_off(hv);
1041 if (SvREADONLY(hv)) {
1042 S_hv_notallowed(aTHX_ k_flags, key, klen,
1043 "Attempt to delete disallowed key '%"SVf"' from"
1044 " a restricted hash");
1047 if (k_flags & HVhek_FREEKEY)
1053 S_hsplit(pTHX_ HV *hv)
1055 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1056 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1057 register I32 newsize = oldsize * 2;
1059 register char *a = xhv->xhv_array; /* HvARRAY(hv) */
1061 register HE **oentry;
1062 int longest_chain = 0;
1065 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1066 hv, (int) oldsize);*/
1068 if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) {
1069 /* Can make this clear any placeholders first for non-restricted hashes,
1070 even though Storable rebuilds restricted hashes by putting in all the
1071 placeholders (first) before turning on the readonly flag, because
1072 Storable always pre-splits the hash. */
1073 hv_clear_placeholders(hv);
1077 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1078 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1084 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1089 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1090 if (oldsize >= 64) {
1091 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1092 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1095 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1099 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1100 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1101 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1104 for (i=0; i<oldsize; i++,aep++) {
1105 int left_length = 0;
1106 int right_length = 0;
1110 if (!*aep) /* non-existent */
1113 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1114 if ((HeHASH(entry) & newsize) != (U32)i) {
1115 *oentry = HeNEXT(entry);
1116 HeNEXT(entry) = *bep;
1118 xhv->xhv_fill++; /* HvFILL(hv)++ */
1124 oentry = &HeNEXT(entry);
1128 if (!*aep) /* everything moved */
1129 xhv->xhv_fill--; /* HvFILL(hv)-- */
1130 /* I think we don't actually need to keep track of the longest length,
1131 merely flag if anything is too long. But for the moment while
1132 developing this code I'll track it. */
1133 if (left_length > longest_chain)
1134 longest_chain = left_length;
1135 if (right_length > longest_chain)
1136 longest_chain = right_length;
1140 /* Pick your policy for "hashing isn't working" here: */
1141 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1146 if (hv == PL_strtab) {
1147 /* Urg. Someone is doing something nasty to the string table.
1152 /* Awooga. Awooga. Pathological data. */
1153 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1154 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1157 Newz(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1158 was_shared = HvSHAREKEYS(hv);
1161 HvSHAREKEYS_off(hv);
1164 aep = (HE **) xhv->xhv_array;
1166 for (i=0; i<newsize; i++,aep++) {
1167 register HE *entry = *aep;
1169 /* We're going to trash this HE's next pointer when we chain it
1170 into the new hash below, so store where we go next. */
1171 HE *next = HeNEXT(entry);
1176 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1181 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1182 hash, HeKFLAGS(entry));
1183 unshare_hek (HeKEY_hek(entry));
1184 HeKEY_hek(entry) = new_hek;
1186 /* Not shared, so simply write the new hash in. */
1187 HeHASH(entry) = hash;
1189 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1190 HEK_REHASH_on(HeKEY_hek(entry));
1191 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1193 /* Copy oentry to the correct new chain. */
1194 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1196 xhv->xhv_fill++; /* HvFILL(hv)++ */
1197 HeNEXT(entry) = *bep;
1203 Safefree (xhv->xhv_array);
1204 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1208 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1210 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1211 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1212 register I32 newsize;
1217 register HE **oentry;
1219 newsize = (I32) newmax; /* possible truncation here */
1220 if (newsize != newmax || newmax <= oldsize)
1222 while ((newsize & (1 + ~newsize)) != newsize) {
1223 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1225 if (newsize < newmax)
1227 if (newsize < newmax)
1228 return; /* overflow detection */
1230 a = xhv->xhv_array; /* HvARRAY(hv) */
1233 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1234 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1240 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1245 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1246 if (oldsize >= 64) {
1247 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1248 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1251 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1254 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1257 Newz(0, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1259 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1260 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1261 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1265 for (i=0; i<oldsize; i++,aep++) {
1266 if (!*aep) /* non-existent */
1268 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1270 if ((j = (HeHASH(entry) & newsize)) != i) {
1272 *oentry = HeNEXT(entry);
1273 if (!(HeNEXT(entry) = aep[j]))
1274 xhv->xhv_fill++; /* HvFILL(hv)++ */
1279 oentry = &HeNEXT(entry);
1281 if (!*aep) /* everything moved */
1282 xhv->xhv_fill--; /* HvFILL(hv)-- */
1289 Creates a new HV. The reference count is set to 1.
1298 register XPVHV* xhv;
1300 hv = (HV*)NEWSV(502,0);
1301 sv_upgrade((SV *)hv, SVt_PVHV);
1302 xhv = (XPVHV*)SvANY(hv);
1305 #ifndef NODEFAULT_SHAREKEYS
1306 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1309 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1310 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1316 Perl_newHVhv(pTHX_ HV *ohv)
1319 STRLEN hv_max, hv_fill;
1321 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1323 hv_max = HvMAX(ohv);
1325 if (!SvMAGICAL((SV *)ohv)) {
1326 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1328 const bool shared = !!HvSHAREKEYS(ohv);
1329 HE **ents, **oents = (HE **)HvARRAY(ohv);
1331 New(0, a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1334 /* In each bucket... */
1335 for (i = 0; i <= hv_max; i++) {
1336 HE *prev = NULL, *ent = NULL, *oent = oents[i];
1343 /* Copy the linked list of entries. */
1344 for (oent = oents[i]; oent; oent = HeNEXT(oent)) {
1345 const U32 hash = HeHASH(oent);
1346 const char * const key = HeKEY(oent);
1347 const STRLEN len = HeKLEN(oent);
1348 const int flags = HeKFLAGS(oent);
1351 HeVAL(ent) = newSVsv(HeVAL(oent));
1353 = shared ? share_hek_flags(key, len, hash, flags)
1354 : save_hek_flags(key, len, hash, flags);
1365 HvFILL(hv) = hv_fill;
1366 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1370 /* Iterate over ohv, copying keys and values one at a time. */
1372 const I32 riter = HvRITER_get(ohv);
1373 HE * const eiter = HvEITER_get(ohv);
1375 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1376 while (hv_max && hv_max + 1 >= hv_fill * 2)
1377 hv_max = hv_max / 2;
1381 while ((entry = hv_iternext_flags(ohv, 0))) {
1382 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1383 newSVsv(HeVAL(entry)), HeHASH(entry),
1386 HvRITER_set(ohv, riter);
1387 HvEITER_set(ohv, eiter);
1394 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1401 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1402 PL_sub_generation++; /* may be deletion of method from stash */
1404 if (HeKLEN(entry) == HEf_SVKEY) {
1405 SvREFCNT_dec(HeKEY_sv(entry));
1406 Safefree(HeKEY_hek(entry));
1408 else if (HvSHAREKEYS(hv))
1409 unshare_hek(HeKEY_hek(entry));
1411 Safefree(HeKEY_hek(entry));
1416 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1420 if (isGV(HeVAL(entry)) && GvCVu(HeVAL(entry)) && HvNAME_get(hv))
1421 PL_sub_generation++; /* may be deletion of method from stash */
1422 sv_2mortal(HeVAL(entry)); /* free between statements */
1423 if (HeKLEN(entry) == HEf_SVKEY) {
1424 sv_2mortal(HeKEY_sv(entry));
1425 Safefree(HeKEY_hek(entry));
1427 else if (HvSHAREKEYS(hv))
1428 unshare_hek(HeKEY_hek(entry));
1430 Safefree(HeKEY_hek(entry));
1435 =for apidoc hv_clear
1437 Clears a hash, making it empty.
1443 Perl_hv_clear(pTHX_ HV *hv)
1446 register XPVHV* xhv;
1450 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1452 xhv = (XPVHV*)SvANY(hv);
1454 if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
1455 /* restricted hash: convert all keys to placeholders */
1457 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1458 HE *entry = ((HE**)xhv->xhv_array)[i];
1459 for (; entry; entry = HeNEXT(entry)) {
1460 /* not already placeholder */
1461 if (HeVAL(entry) != &PL_sv_placeholder) {
1462 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1463 SV* keysv = hv_iterkeysv(entry);
1465 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1468 SvREFCNT_dec(HeVAL(entry));
1469 HeVAL(entry) = &PL_sv_placeholder;
1470 HvPLACEHOLDERS(hv)++;
1478 HvPLACEHOLDERS_set(hv, 0);
1479 if (xhv->xhv_array /* HvARRAY(hv) */)
1480 (void)memzero(xhv->xhv_array /* HvARRAY(hv) */,
1481 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1486 HvHASKFLAGS_off(hv);
1490 HvEITER_set(hv, NULL);
1495 =for apidoc hv_clear_placeholders
1497 Clears any placeholders from a hash. If a restricted hash has any of its keys
1498 marked as readonly and the key is subsequently deleted, the key is not actually
1499 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1500 it so it will be ignored by future operations such as iterating over the hash,
1501 but will still allow the hash to have a value reassigned to the key at some
1502 future point. This function clears any such placeholder keys from the hash.
1503 See Hash::Util::lock_keys() for an example of its use.
1509 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1512 I32 items = (I32)HvPLACEHOLDERS(hv);
1519 /* Loop down the linked list heads */
1521 HE **oentry = &(HvARRAY(hv))[i];
1522 HE *entry = *oentry;
1527 for (; entry; entry = *oentry) {
1528 if (HeVAL(entry) == &PL_sv_placeholder) {
1529 *oentry = HeNEXT(entry);
1530 if (first && !*oentry)
1531 HvFILL(hv)--; /* This linked list is now empty. */
1532 if (HvEITER_get(hv))
1535 hv_free_ent(hv, entry);
1539 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS(hv);
1540 if (HvKEYS(hv) == 0)
1541 HvHASKFLAGS_off(hv);
1542 HvPLACEHOLDERS(hv) = 0;
1546 oentry = &HeNEXT(entry);
1551 /* You can't get here, hence assertion should always fail. */
1552 assert (items == 0);
1557 S_hfreeentries(pTHX_ HV *hv)
1559 register HE **array;
1563 struct xpvhv_aux *iter;
1572 array = HvARRAY(hv);
1573 /* make everyone else think the array is empty, so that the destructors
1574 * called for freed entries can't recusively mess with us */
1575 HvARRAY(hv) = Null(HE**);
1577 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1582 register HE *oentry = entry;
1583 entry = HeNEXT(entry);
1584 hv_free_ent(hv, oentry);
1589 entry = array[riter];
1592 HvARRAY(hv) = array;
1594 iter = ((XPVHV*) SvANY(hv))->xhv_aux;
1596 entry = iter->xhv_eiter; /* HvEITER(hv) */
1597 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1599 hv_free_ent(hv, entry);
1602 ((XPVHV*) SvANY(hv))->xhv_aux = 0;
1607 =for apidoc hv_undef
1615 Perl_hv_undef(pTHX_ HV *hv)
1617 register XPVHV* xhv;
1621 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1622 xhv = (XPVHV*)SvANY(hv);
1624 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1625 if ((name = HvNAME_get(hv))) {
1626 /* FIXME - strlen HvNAME */
1628 hv_delete(PL_stashcache, name, strlen(name), G_DISCARD);
1629 Perl_hv_name_set(aTHX_ hv, 0, 0, 0);
1631 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1632 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
1633 HvPLACEHOLDERS_set(hv, 0);
1640 S_hv_auxinit(aTHX) {
1641 struct xpvhv_aux *iter;
1643 New(0, iter, 1, struct xpvhv_aux);
1645 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1646 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1653 =for apidoc hv_iterinit
1655 Prepares a starting point to traverse a hash table. Returns the number of
1656 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1657 currently only meaningful for hashes without tie magic.
1659 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1660 hash buckets that happen to be in use. If you still need that esoteric
1661 value, you can get it through the macro C<HvFILL(tb)>.
1668 Perl_hv_iterinit(pTHX_ HV *hv)
1670 register XPVHV* xhv;
1672 struct xpvhv_aux *iter;
1675 Perl_croak(aTHX_ "Bad hash");
1676 xhv = (XPVHV*)SvANY(hv);
1678 iter = xhv->xhv_aux;
1680 entry = iter->xhv_eiter; /* HvEITER(hv) */
1681 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1683 hv_free_ent(hv, entry);
1685 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1686 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1688 xhv->xhv_aux = S_hv_auxinit(aTHX);
1691 /* used to be xhv->xhv_fill before 5.004_65 */
1692 return XHvTOTALKEYS(xhv);
1696 Perl_hv_riter_p(pTHX_ HV *hv) {
1697 struct xpvhv_aux *iter;
1700 Perl_croak(aTHX_ "Bad hash");
1702 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1704 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1706 return &(iter->xhv_riter);
1710 Perl_hv_eiter_p(pTHX_ HV *hv) {
1711 struct xpvhv_aux *iter;
1714 Perl_croak(aTHX_ "Bad hash");
1716 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1718 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1720 return &(iter->xhv_eiter);
1724 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1725 struct xpvhv_aux *iter;
1728 Perl_croak(aTHX_ "Bad hash");
1731 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1736 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1738 iter->xhv_riter = riter;
1742 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1743 struct xpvhv_aux *iter;
1746 Perl_croak(aTHX_ "Bad hash");
1748 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1750 /* 0 is the default so don't go malloc()ing a new structure just to
1755 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1757 iter->xhv_eiter = eiter;
1762 Perl_hv_name_p(pTHX_ HV *hv)
1764 struct xpvhv_aux *iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1767 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1769 return &(iter->xhv_name);
1773 Perl_hv_name_set(pTHX_ HV *hv, const char *name, STRLEN len, int flags)
1775 struct xpvhv_aux *iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1781 ((XPVHV *)SvANY(hv))->xhv_aux = iter = S_hv_auxinit(aTHX);
1783 iter->xhv_name = savepvn(name, len);
1787 =for apidoc hv_iternext
1789 Returns entries from a hash iterator. See C<hv_iterinit>.
1791 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1792 iterator currently points to, without losing your place or invalidating your
1793 iterator. Note that in this case the current entry is deleted from the hash
1794 with your iterator holding the last reference to it. Your iterator is flagged
1795 to free the entry on the next call to C<hv_iternext>, so you must not discard
1796 your iterator immediately else the entry will leak - call C<hv_iternext> to
1797 trigger the resource deallocation.
1803 Perl_hv_iternext(pTHX_ HV *hv)
1805 return hv_iternext_flags(hv, 0);
1809 =for apidoc hv_iternext_flags
1811 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1812 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1813 set the placeholders keys (for restricted hashes) will be returned in addition
1814 to normal keys. By default placeholders are automatically skipped over.
1815 Currently a placeholder is implemented with a value that is
1816 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1817 restricted hashes may change, and the implementation currently is
1818 insufficiently abstracted for any change to be tidy.
1824 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1827 register XPVHV* xhv;
1831 struct xpvhv_aux *iter;
1834 Perl_croak(aTHX_ "Bad hash");
1835 xhv = (XPVHV*)SvANY(hv);
1836 iter = xhv->xhv_aux;
1839 /* Too many things (well, pp_each at least) merrily assume that you can
1840 call iv_iternext without calling hv_iterinit, so we'll have to deal
1843 iter = ((XPVHV *)SvANY(hv))->xhv_aux;
1846 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
1848 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1849 SV *key = sv_newmortal();
1851 sv_setsv(key, HeSVKEY_force(entry));
1852 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1858 /* one HE per MAGICAL hash */
1859 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1861 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1863 HeKEY_hek(entry) = hek;
1864 HeKLEN(entry) = HEf_SVKEY;
1866 magic_nextpack((SV*) hv,mg,key);
1868 /* force key to stay around until next time */
1869 HeSVKEY_set(entry, SvREFCNT_inc(key));
1870 return entry; /* beware, hent_val is not set */
1873 SvREFCNT_dec(HeVAL(entry));
1874 Safefree(HeKEY_hek(entry));
1876 iter->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1879 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1880 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1884 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1885 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
1886 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1888 /* At start of hash, entry is NULL. */
1891 entry = HeNEXT(entry);
1892 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1894 * Skip past any placeholders -- don't want to include them in
1897 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1898 entry = HeNEXT(entry);
1903 /* OK. Come to the end of the current list. Grab the next one. */
1905 iter->xhv_riter++; /* HvRITER(hv)++ */
1906 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1907 /* There is no next one. End of the hash. */
1908 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1911 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
1912 entry = ((HE**)xhv->xhv_array)[iter->xhv_riter];
1914 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1915 /* If we have an entry, but it's a placeholder, don't count it.
1917 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1918 entry = HeNEXT(entry);
1920 /* Will loop again if this linked list starts NULL
1921 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1922 or if we run through it and find only placeholders. */
1925 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1927 hv_free_ent(hv, oldentry);
1930 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1931 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1933 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
1938 =for apidoc hv_iterkey
1940 Returns the key from the current position of the hash iterator. See
1947 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1949 if (HeKLEN(entry) == HEf_SVKEY) {
1951 char *p = SvPV(HeKEY_sv(entry), len);
1956 *retlen = HeKLEN(entry);
1957 return HeKEY(entry);
1961 /* unlike hv_iterval(), this always returns a mortal copy of the key */
1963 =for apidoc hv_iterkeysv
1965 Returns the key as an C<SV*> from the current position of the hash
1966 iterator. The return value will always be a mortal copy of the key. Also
1973 Perl_hv_iterkeysv(pTHX_ register HE *entry)
1975 if (HeKLEN(entry) != HEf_SVKEY) {
1976 HEK *hek = HeKEY_hek(entry);
1977 const int flags = HEK_FLAGS(hek);
1980 if (flags & HVhek_WASUTF8) {
1982 Andreas would like keys he put in as utf8 to come back as utf8
1984 STRLEN utf8_len = HEK_LEN(hek);
1985 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
1987 sv = newSVpvn ((char*)as_utf8, utf8_len);
1989 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
1990 } else if (flags & HVhek_REHASH) {
1991 /* We don't have a pointer to the hv, so we have to replicate the
1992 flag into every HEK. This hv is using custom a hasing
1993 algorithm. Hence we can't return a shared string scalar, as
1994 that would contain the (wrong) hash value, and might get passed
1995 into an hv routine with a regular hash */
1997 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
2001 sv = newSVpvn_share(HEK_KEY(hek),
2002 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
2005 return sv_2mortal(sv);
2007 return sv_mortalcopy(HeKEY_sv(entry));
2011 =for apidoc hv_iterval
2013 Returns the value from the current position of the hash iterator. See
2020 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2022 if (SvRMAGICAL(hv)) {
2023 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2024 SV* sv = sv_newmortal();
2025 if (HeKLEN(entry) == HEf_SVKEY)
2026 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2028 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2032 return HeVAL(entry);
2036 =for apidoc hv_iternextsv
2038 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2045 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2048 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
2050 *key = hv_iterkey(he, retlen);
2051 return hv_iterval(hv, he);
2055 =for apidoc hv_magic
2057 Adds magic to a hash. See C<sv_magic>.
2063 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
2065 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
2068 #if 0 /* use the macro from hv.h instead */
2071 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
2073 return HEK_KEY(share_hek(sv, len, hash));
2078 /* possibly free a shared string if no one has access to it
2079 * len and hash must both be valid for str.
2082 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2084 unshare_hek_or_pvn (NULL, str, len, hash);
2089 Perl_unshare_hek(pTHX_ HEK *hek)
2091 unshare_hek_or_pvn(hek, NULL, 0, 0);
2094 /* possibly free a shared string if no one has access to it
2095 hek if non-NULL takes priority over the other 3, else str, len and hash
2096 are used. If so, len and hash must both be valid for str.
2099 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
2101 register XPVHV* xhv;
2103 register HE **oentry;
2106 bool is_utf8 = FALSE;
2108 const char *save = str;
2111 hash = HEK_HASH(hek);
2112 } else if (len < 0) {
2113 STRLEN tmplen = -len;
2115 /* See the note in hv_fetch(). --jhi */
2116 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2119 k_flags = HVhek_UTF8;
2121 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2124 /* what follows is the moral equivalent of:
2125 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2126 if (--*Svp == Nullsv)
2127 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2129 xhv = (XPVHV*)SvANY(PL_strtab);
2130 /* assert(xhv_array != 0) */
2132 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2133 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2135 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2136 if (HeKEY_hek(entry) != hek)
2142 const int flags_masked = k_flags & HVhek_MASK;
2143 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2144 if (HeHASH(entry) != hash) /* strings can't be equal */
2146 if (HeKLEN(entry) != len)
2148 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2150 if (HeKFLAGS(entry) != flags_masked)
2158 if (--HeVAL(entry) == Nullsv) {
2159 *oentry = HeNEXT(entry);
2161 xhv->xhv_fill--; /* HvFILL(hv)-- */
2162 Safefree(HeKEY_hek(entry));
2164 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2168 UNLOCK_STRTAB_MUTEX;
2169 if (!found && ckWARN_d(WARN_INTERNAL))
2170 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2171 "Attempt to free non-existent shared string '%s'%s"
2173 hek ? HEK_KEY(hek) : str,
2174 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2175 if (k_flags & HVhek_FREEKEY)
2179 /* get a (constant) string ptr from the global string table
2180 * string will get added if it is not already there.
2181 * len and hash must both be valid for str.
2184 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2186 bool is_utf8 = FALSE;
2188 const char *save = str;
2191 STRLEN tmplen = -len;
2193 /* See the note in hv_fetch(). --jhi */
2194 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2196 /* If we were able to downgrade here, then than means that we were passed
2197 in a key which only had chars 0-255, but was utf8 encoded. */
2200 /* If we found we were able to downgrade the string to bytes, then
2201 we should flag that it needs upgrading on keys or each. Also flag
2202 that we need share_hek_flags to free the string. */
2204 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2207 return share_hek_flags (str, len, hash, flags);
2211 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2213 register XPVHV* xhv;
2215 register HE **oentry;
2218 const int flags_masked = flags & HVhek_MASK;
2220 /* what follows is the moral equivalent of:
2222 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2223 hv_store(PL_strtab, str, len, Nullsv, hash);
2225 Can't rehash the shared string table, so not sure if it's worth
2226 counting the number of entries in the linked list
2228 xhv = (XPVHV*)SvANY(PL_strtab);
2229 /* assert(xhv_array != 0) */
2231 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2232 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2233 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2234 if (HeHASH(entry) != hash) /* strings can't be equal */
2236 if (HeKLEN(entry) != len)
2238 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2240 if (HeKFLAGS(entry) != flags_masked)
2247 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2248 HeVAL(entry) = Nullsv;
2249 HeNEXT(entry) = *oentry;
2251 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2252 if (i) { /* initial entry? */
2253 xhv->xhv_fill++; /* HvFILL(hv)++ */
2254 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2259 ++HeVAL(entry); /* use value slot as REFCNT */
2260 UNLOCK_STRTAB_MUTEX;
2262 if (flags & HVhek_FREEKEY)
2265 return HeKEY_hek(entry);
2269 Perl_hv_placeholders_p(pTHX_ HV *hv)
2272 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2275 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2278 Perl_die(aTHX_ "panic: hv_placeholders_p");
2281 return &(mg->mg_len);
2286 Perl_hv_placeholders_get(pTHX_ HV *hv)
2289 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2291 return mg ? mg->mg_len : 0;
2295 Perl_hv_placeholders_set(pTHX_ HV *hv, IV ph)
2298 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2303 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2304 Perl_die(aTHX_ "panic: hv_placeholders_set");
2306 /* else we don't need to add magic to record 0 placeholders. */
2310 =for apidoc hv_assert
2312 Check that a hash is in an internally consistent state.
2318 Perl_hv_assert(pTHX_ HV *hv)
2323 int placeholders = 0;
2326 const I32 riter = HvRITER_get(hv);
2327 HE *eiter = HvEITER_get(hv);
2329 (void)hv_iterinit(hv);
2331 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2332 /* sanity check the values */
2333 if (HeVAL(entry) == &PL_sv_placeholder) {
2338 /* sanity check the keys */
2339 if (HeSVKEY(entry)) {
2340 /* Don't know what to check on SV keys. */
2341 } else if (HeKUTF8(entry)) {
2343 if (HeKWASUTF8(entry)) {
2344 PerlIO_printf(Perl_debug_log,
2345 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2346 (int) HeKLEN(entry), HeKEY(entry));
2349 } else if (HeKWASUTF8(entry)) {
2353 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2354 if (HvUSEDKEYS(hv) != real) {
2355 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2356 (int) real, (int) HvUSEDKEYS(hv));
2359 if (HvPLACEHOLDERS(hv) != placeholders) {
2360 PerlIO_printf(Perl_debug_log,
2361 "Count %d placeholder(s), but hash reports %d\n",
2362 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2366 if (withflags && ! HvHASKFLAGS(hv)) {
2367 PerlIO_printf(Perl_debug_log,
2368 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2375 HvRITER_set(hv, riter); /* Restore hash iterator state */
2376 HvEITER_set(hv, eiter);
2381 * c-indentation-style: bsd
2383 * indent-tabs-mode: t
2386 * ex: set ts=8 sts=4 sw=4 noet: