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;
63 New(54, he, PERL_ARENA_SIZE/sizeof(HE), HE);
64 HeNEXT(he) = PL_he_arenaroot;
67 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
70 HeNEXT(he) = (HE*)(he + 1);
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(), *esv = 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_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg);
177 Perl_croak(aTHX_ SvPVX(esv), sv);
180 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
183 #define HV_FETCH_ISSTORE 0x01
184 #define HV_FETCH_ISEXISTS 0x02
185 #define HV_FETCH_LVALUE 0x04
186 #define HV_FETCH_JUST_SV 0x08
191 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
192 the length of the key. The C<hash> parameter is the precomputed hash
193 value; if it is zero then Perl will compute it. The return value will be
194 NULL if the operation failed or if the value did not need to be actually
195 stored within the hash (as in the case of tied hashes). Otherwise it can
196 be dereferenced to get the original C<SV*>. Note that the caller is
197 responsible for suitably incrementing the reference count of C<val> before
198 the call, and decrementing it if the function returned NULL. Effectively
199 a successful hv_store takes ownership of one reference to C<val>. This is
200 usually what you want; a newly created SV has a reference count of one, so
201 if all your code does is create SVs then store them in a hash, hv_store
202 will own the only reference to the new SV, and your code doesn't need to do
203 anything further to tidy up. hv_store is not implemented as a call to
204 hv_store_ent, and does not create a temporary SV for the key, so if your
205 key data is not already in SV form then use hv_store in preference to
208 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
209 information on how to use this function on tied hashes.
215 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
228 hek = hv_fetch_common (hv, NULL, key, klen, flags,
229 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
230 return hek ? &HeVAL(hek) : NULL;
234 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
235 register U32 hash, int flags)
237 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
238 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
239 return hek ? &HeVAL(hek) : NULL;
243 =for apidoc hv_store_ent
245 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
246 parameter is the precomputed hash value; if it is zero then Perl will
247 compute it. The return value is the new hash entry so created. It will be
248 NULL if the operation failed or if the value did not need to be actually
249 stored within the hash (as in the case of tied hashes). Otherwise the
250 contents of the return value can be accessed using the C<He?> macros
251 described here. Note that the caller is responsible for suitably
252 incrementing the reference count of C<val> before the call, and
253 decrementing it if the function returned NULL. Effectively a successful
254 hv_store_ent takes ownership of one reference to C<val>. This is
255 usually what you want; a newly created SV has a reference count of one, so
256 if all your code does is create SVs then store them in a hash, hv_store
257 will own the only reference to the new SV, and your code doesn't need to do
258 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
259 unlike C<val> it does not take ownership of it, so maintaining the correct
260 reference count on C<key> is entirely the caller's responsibility. hv_store
261 is not implemented as a call to hv_store_ent, and does not create a temporary
262 SV for the key, so if your key data is not already in SV form then use
263 hv_store in preference to hv_store_ent.
265 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
266 information on how to use this function on tied hashes.
272 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
274 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
278 =for apidoc hv_exists
280 Returns a boolean indicating whether the specified hash key exists. The
281 C<klen> is the length of the key.
287 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
299 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
306 Returns the SV which corresponds to the specified key in the hash. The
307 C<klen> is the length of the key. If C<lval> is set then the fetch will be
308 part of a store. Check that the return value is non-null before
309 dereferencing it to an C<SV*>.
311 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
312 information on how to use this function on tied hashes.
318 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
331 hek = hv_fetch_common (hv, NULL, key, klen, flags,
332 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
334 return hek ? &HeVAL(hek) : NULL;
338 =for apidoc hv_exists_ent
340 Returns a boolean indicating whether the specified hash key exists. C<hash>
341 can be a valid precomputed hash value, or 0 to ask for it to be
348 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
350 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
354 /* returns an HE * structure with the all fields set */
355 /* note that hent_val will be a mortal sv for MAGICAL hashes */
357 =for apidoc hv_fetch_ent
359 Returns the hash entry which corresponds to the specified key in the hash.
360 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
361 if you want the function to compute it. IF C<lval> is set then the fetch
362 will be part of a store. Make sure the return value is non-null before
363 accessing it. The return value when C<tb> is a tied hash is a pointer to a
364 static location, so be sure to make a copy of the structure if you need to
367 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
368 information on how to use this function on tied hashes.
374 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
376 return hv_fetch_common(hv, keysv, NULL, 0, 0,
377 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
381 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
382 int flags, int action, SV *val, register U32 hash)
397 if (flags & HVhek_FREEKEY)
399 key = SvPV(keysv, klen);
401 is_utf8 = (SvUTF8(keysv) != 0);
403 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
406 xhv = (XPVHV*)SvANY(hv);
408 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
410 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
413 /* XXX should be able to skimp on the HE/HEK here when
414 HV_FETCH_JUST_SV is true. */
417 keysv = newSVpvn(key, klen);
422 keysv = newSVsv(keysv);
424 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
426 /* grab a fake HE/HEK pair from the pool or make a new one */
427 entry = PL_hv_fetch_ent_mh;
429 PL_hv_fetch_ent_mh = HeNEXT(entry);
433 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
434 HeKEY_hek(entry) = (HEK*)k;
436 HeNEXT(entry) = Nullhe;
437 HeSVKEY_set(entry, keysv);
439 sv_upgrade(sv, SVt_PVLV);
441 /* so we can free entry when freeing sv */
442 LvTARG(sv) = (SV*)entry;
444 /* XXX remove at some point? */
445 if (flags & HVhek_FREEKEY)
450 #ifdef ENV_IS_CASELESS
451 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
453 for (i = 0; i < klen; ++i)
454 if (isLOWER(key[i])) {
455 /* Would be nice if we had a routine to do the
456 copy and upercase in a single pass through. */
457 const char *nkey = strupr(savepvn(key,klen));
458 /* Note that this fetch is for nkey (the uppercased
459 key) whereas the store is for key (the original) */
460 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
461 HVhek_FREEKEY, /* free nkey */
462 0 /* non-LVAL fetch */,
463 Nullsv /* no value */,
464 0 /* compute hash */);
465 if (!entry && (action & HV_FETCH_LVALUE)) {
466 /* This call will free key if necessary.
467 Do it this way to encourage compiler to tail
469 entry = hv_fetch_common(hv, keysv, key, klen,
470 flags, HV_FETCH_ISSTORE,
473 if (flags & HVhek_FREEKEY)
481 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
482 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
484 /* I don't understand why hv_exists_ent has svret and sv,
485 whereas hv_exists only had one. */
486 svret = sv_newmortal();
489 if (keysv || is_utf8) {
491 keysv = newSVpvn(key, klen);
494 keysv = newSVsv(keysv);
496 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
498 mg_copy((SV*)hv, sv, key, klen);
500 if (flags & HVhek_FREEKEY)
502 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
503 /* This cast somewhat evil, but I'm merely using NULL/
504 not NULL to return the boolean exists.
505 And I know hv is not NULL. */
506 return SvTRUE(svret) ? (HE *)hv : NULL;
508 #ifdef ENV_IS_CASELESS
509 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
510 /* XXX This code isn't UTF8 clean. */
511 const char *keysave = key;
512 /* Will need to free this, so set FREEKEY flag. */
513 key = savepvn(key,klen);
514 key = (const char*)strupr((char*)key);
519 if (flags & HVhek_FREEKEY) {
522 flags |= HVhek_FREEKEY;
526 else if (action & HV_FETCH_ISSTORE) {
529 hv_magic_check (hv, &needs_copy, &needs_store);
531 bool save_taint = PL_tainted;
532 if (keysv || is_utf8) {
534 keysv = newSVpvn(key, klen);
538 PL_tainted = SvTAINTED(keysv);
539 keysv = sv_2mortal(newSVsv(keysv));
540 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
542 mg_copy((SV*)hv, val, key, klen);
545 TAINT_IF(save_taint);
546 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) {
547 if (flags & HVhek_FREEKEY)
551 #ifdef ENV_IS_CASELESS
552 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
553 /* XXX This code isn't UTF8 clean. */
554 const char *keysave = key;
555 /* Will need to free this, so set FREEKEY flag. */
556 key = savepvn(key,klen);
557 key = (const char*)strupr((char*)key);
562 if (flags & HVhek_FREEKEY) {
565 flags |= HVhek_FREEKEY;
572 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
573 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
574 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
575 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
578 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
579 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
581 #ifdef DYNAMIC_ENV_FETCH
582 else if (action & HV_FETCH_ISEXISTS) {
583 /* for an %ENV exists, if we do an insert it's by a recursive
584 store call, so avoid creating HvARRAY(hv) right now. */
588 /* XXX remove at some point? */
589 if (flags & HVhek_FREEKEY)
597 const char *keysave = key;
598 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
602 flags &= ~HVhek_UTF8;
603 if (key != keysave) {
604 if (flags & HVhek_FREEKEY)
606 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
611 PERL_HASH_INTERNAL(hash, key, klen);
612 /* We don't have a pointer to the hv, so we have to replicate the
613 flag into every HEK, so that hv_iterkeysv can see it. */
614 /* And yes, you do need this even though you are not "storing" because
615 you can flip the flags below if doing an lval lookup. (And that
616 was put in to give the semantics Andreas was expecting.) */
617 flags |= HVhek_REHASH;
619 if (keysv && (SvIsCOW_shared_hash(keysv))) {
622 PERL_HASH(hash, key, klen);
626 masked_flags = (flags & HVhek_MASK);
629 #ifdef DYNAMIC_ENV_FETCH
630 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
634 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
635 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
637 for (; entry; ++n_links, entry = HeNEXT(entry)) {
638 if (HeHASH(entry) != hash) /* strings can't be equal */
640 if (HeKLEN(entry) != (I32)klen)
642 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
644 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
647 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
648 if (HeKFLAGS(entry) != masked_flags) {
649 /* We match if HVhek_UTF8 bit in our flags and hash key's
650 match. But if entry was set previously with HVhek_WASUTF8
651 and key now doesn't (or vice versa) then we should change
652 the key's flag, as this is assignment. */
653 if (HvSHAREKEYS(hv)) {
654 /* Need to swap the key we have for a key with the flags we
655 need. As keys are shared we can't just write to the
656 flag, so we share the new one, unshare the old one. */
657 HEK *new_hek = share_hek_flags(key, klen, hash,
659 unshare_hek (HeKEY_hek(entry));
660 HeKEY_hek(entry) = new_hek;
663 HeKFLAGS(entry) = masked_flags;
664 if (masked_flags & HVhek_ENABLEHVKFLAGS)
667 if (HeVAL(entry) == &PL_sv_placeholder) {
668 /* yes, can store into placeholder slot */
669 if (action & HV_FETCH_LVALUE) {
671 /* This preserves behaviour with the old hv_fetch
672 implementation which at this point would bail out
673 with a break; (at "if we find a placeholder, we
674 pretend we haven't found anything")
676 That break mean that if a placeholder were found, it
677 caused a call into hv_store, which in turn would
678 check magic, and if there is no magic end up pretty
679 much back at this point (in hv_store's code). */
682 /* LVAL fetch which actaully needs a store. */
684 xhv->xhv_placeholders--;
687 if (val != &PL_sv_placeholder)
688 xhv->xhv_placeholders--;
691 } else if (action & HV_FETCH_ISSTORE) {
692 SvREFCNT_dec(HeVAL(entry));
695 } else if (HeVAL(entry) == &PL_sv_placeholder) {
696 /* if we find a placeholder, we pretend we haven't found
700 if (flags & HVhek_FREEKEY)
704 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
705 if (!(action & HV_FETCH_ISSTORE)
706 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
708 char *env = PerlEnv_ENVgetenv_len(key,&len);
710 sv = newSVpvn(env,len);
712 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
718 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
719 S_hv_notallowed(aTHX_ flags, key, klen,
720 "access disallowed key '%"SVf"' in"
723 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
724 /* Not doing some form of store, so return failure. */
725 if (flags & HVhek_FREEKEY)
729 if (action & HV_FETCH_LVALUE) {
732 /* At this point the old hv_fetch code would call to hv_store,
733 which in turn might do some tied magic. So we need to make that
734 magic check happen. */
735 /* gonna assign to this, so it better be there */
736 return hv_fetch_common(hv, keysv, key, klen, flags,
737 HV_FETCH_ISSTORE, val, hash);
738 /* XXX Surely that could leak if the fetch-was-store fails?
739 Just like the hv_fetch. */
743 /* Welcome to hv_store... */
745 if (!xhv->xhv_array) {
746 /* Not sure if we can get here. I think the only case of oentry being
747 NULL is for %ENV with dynamic env fetch. But that should disappear
748 with magic in the previous code. */
749 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
750 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
754 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
757 /* share_hek_flags will do the free for us. This might be considered
760 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
761 else /* gotta do the real thing */
762 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
764 HeNEXT(entry) = *oentry;
767 if (val == &PL_sv_placeholder)
768 xhv->xhv_placeholders++;
769 if (masked_flags & HVhek_ENABLEHVKFLAGS)
772 xhv->xhv_keys++; /* HvKEYS(hv)++ */
773 if (!n_links) { /* initial entry? */
774 xhv->xhv_fill++; /* HvFILL(hv)++ */
775 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
776 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
777 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
778 splits on a rehashed hash, as we're not going to split it again,
779 and if someone is lucky (evil) enough to get all the keys in one
780 list they could exhaust our memory as we repeatedly double the
781 number of buckets on every entry. Linear search feels a less worse
790 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
792 MAGIC *mg = SvMAGIC(hv);
796 if (isUPPER(mg->mg_type)) {
798 switch (mg->mg_type) {
799 case PERL_MAGIC_tied:
801 *needs_store = FALSE;
804 mg = mg->mg_moremagic;
809 =for apidoc hv_scalar
811 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
817 Perl_hv_scalar(pTHX_ HV *hv)
822 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
823 sv = magic_scalarpack(hv, mg);
829 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
830 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
838 =for apidoc hv_delete
840 Deletes a key/value pair in the hash. The value SV is removed from the
841 hash and returned to the caller. The C<klen> is the length of the key.
842 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
849 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
856 k_flags |= HVhek_UTF8;
860 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
864 =for apidoc hv_delete_ent
866 Deletes a key/value pair in the hash. The value SV is removed from the
867 hash and returned to the caller. The C<flags> value will normally be zero;
868 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
869 precomputed hash value, or 0 to ask for it to be computed.
875 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
877 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
881 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
882 int k_flags, I32 d_flags, U32 hash)
888 register HE **oentry;
897 if (k_flags & HVhek_FREEKEY)
899 key = SvPV(keysv, klen);
901 is_utf8 = (SvUTF8(keysv) != 0);
903 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
906 if (SvRMAGICAL(hv)) {
909 hv_magic_check (hv, &needs_copy, &needs_store);
912 entry = hv_fetch_common(hv, keysv, key, klen,
913 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
915 sv = entry ? HeVAL(entry) : NULL;
921 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
922 /* No longer an element */
923 sv_unmagic(sv, PERL_MAGIC_tiedelem);
926 return Nullsv; /* element cannot be deleted */
928 #ifdef ENV_IS_CASELESS
929 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
930 /* XXX This code isn't UTF8 clean. */
931 keysv = sv_2mortal(newSVpvn(key,klen));
932 if (k_flags & HVhek_FREEKEY) {
935 key = strupr(SvPVX(keysv));
944 xhv = (XPVHV*)SvANY(hv);
945 if (!xhv->xhv_array /* !HvARRAY(hv) */)
949 const char *keysave = key;
950 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
953 k_flags |= HVhek_UTF8;
955 k_flags &= ~HVhek_UTF8;
956 if (key != keysave) {
957 if (k_flags & HVhek_FREEKEY) {
958 /* This shouldn't happen if our caller does what we expect,
959 but strictly the API allows it. */
962 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
964 HvHASKFLAGS_on((SV*)hv);
968 PERL_HASH_INTERNAL(hash, key, klen);
970 if (keysv && (SvIsCOW_shared_hash(keysv))) {
973 PERL_HASH(hash, key, klen);
977 masked_flags = (k_flags & HVhek_MASK);
979 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
980 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
983 for (; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
984 if (HeHASH(entry) != hash) /* strings can't be equal */
986 if (HeKLEN(entry) != (I32)klen)
988 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
990 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
993 /* if placeholder is here, it's already been deleted.... */
994 if (HeVAL(entry) == &PL_sv_placeholder)
996 if (k_flags & HVhek_FREEKEY)
1000 else if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1001 S_hv_notallowed(aTHX_ k_flags, key, klen,
1002 "delete readonly key '%"SVf"' from"
1005 if (k_flags & HVhek_FREEKEY)
1008 if (d_flags & G_DISCARD)
1011 sv = sv_2mortal(HeVAL(entry));
1012 HeVAL(entry) = &PL_sv_placeholder;
1016 * If a restricted hash, rather than really deleting the entry, put
1017 * a placeholder there. This marks the key as being "approved", so
1018 * we can still access via not-really-existing key without raising
1021 if (SvREADONLY(hv)) {
1022 SvREFCNT_dec(HeVAL(entry));
1023 HeVAL(entry) = &PL_sv_placeholder;
1024 /* We'll be saving this slot, so the number of allocated keys
1025 * doesn't go down, but the number placeholders goes up */
1026 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1028 *oentry = HeNEXT(entry);
1030 xhv->xhv_fill--; /* HvFILL(hv)-- */
1031 if (entry == xhv->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 "delete disallowed key '%"SVf"' from"
1047 if (k_flags & HVhek_FREEKEY)
1053 S_hsplit(pTHX_ HV *hv)
1055 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1056 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) */
1063 register HE **oentry;
1064 int longest_chain = 0;
1067 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1068 hv, (int) oldsize);*/
1070 if (HvPLACEHOLDERS(hv) && !SvREADONLY(hv)) {
1071 /* Can make this clear any placeholders first for non-restricted hashes,
1072 even though Storable rebuilds restricted hashes by putting in all the
1073 placeholders (first) before turning on the readonly flag, because
1074 Storable always pre-splits the hash. */
1075 hv_clear_placeholders(hv);
1079 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1080 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1086 New(2, a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1091 Copy(xhv->xhv_array /* HvARRAY(hv) */, a, oldsize * sizeof(HE*), char);
1092 if (oldsize >= 64) {
1093 offer_nice_chunk(xhv->xhv_array /* HvARRAY(hv) */,
1094 PERL_HV_ARRAY_ALLOC_BYTES(oldsize));
1097 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1101 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1102 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1103 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1106 for (i=0; i<oldsize; i++,aep++) {
1107 int left_length = 0;
1108 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++) {
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);
1175 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1180 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1181 hash, HeKFLAGS(entry));
1182 unshare_hek (HeKEY_hek(entry));
1183 HeKEY_hek(entry) = new_hek;
1185 /* Not shared, so simply write the new hash in. */
1186 HeHASH(entry) = hash;
1188 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1189 HEK_REHASH_on(HeKEY_hek(entry));
1190 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1192 /* Copy oentry to the correct new chain. */
1193 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1195 xhv->xhv_fill++; /* HvFILL(hv)++ */
1196 HeNEXT(entry) = *bep;
1202 Safefree (xhv->xhv_array);
1203 xhv->xhv_array = a; /* HvARRAY(hv) = a */
1207 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1209 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1210 I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1211 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) {
1269 if ((j = (HeHASH(entry) & newsize)) != i) {
1271 *oentry = HeNEXT(entry);
1272 if (!(HeNEXT(entry) = aep[j]))
1273 xhv->xhv_fill++; /* HvFILL(hv)++ */
1278 oentry = &HeNEXT(entry);
1280 if (!*aep) /* everything moved */
1281 xhv->xhv_fill--; /* HvFILL(hv)-- */
1288 Creates a new HV. The reference count is set to 1.
1297 register XPVHV* xhv;
1299 hv = (HV*)NEWSV(502,0);
1300 sv_upgrade((SV *)hv, SVt_PVHV);
1301 xhv = (XPVHV*)SvANY(hv);
1304 #ifndef NODEFAULT_SHAREKEYS
1305 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1308 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1309 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1310 xhv->xhv_pmroot = 0; /* HvPMROOT(hv) = 0 */
1311 (void)hv_iterinit(hv); /* so each() will start off right */
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 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 U32 hash = HeHASH(oent);
1346 char *key = HeKEY(oent);
1347 STRLEN len = HeKLEN(oent);
1348 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 I32 riter = HvRITER(ohv);
1373 HE *eiter = HvEITER(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(ohv) = riter;
1387 HvEITER(ohv) = eiter;
1394 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1401 if (val && isGV(val) && GvCVu(val) && HvNAME(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(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 */
1458 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1459 entry = ((HE**)xhv->xhv_array)[i];
1460 for (; entry; entry = HeNEXT(entry)) {
1461 /* not already placeholder */
1462 if (HeVAL(entry) != &PL_sv_placeholder) {
1463 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1464 SV* keysv = hv_iterkeysv(entry);
1466 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1469 SvREFCNT_dec(HeVAL(entry));
1470 HeVAL(entry) = &PL_sv_placeholder;
1471 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1479 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1480 if (xhv->xhv_array /* HvARRAY(hv) */)
1481 (void)memzero(xhv->xhv_array /* HvARRAY(hv) */,
1482 (xhv->xhv_max+1 /* HvMAX(hv)+1 */) * sizeof(HE*));
1487 HvHASKFLAGS_off(hv);
1494 =for apidoc hv_clear_placeholders
1496 Clears any placeholders from a hash. If a restricted hash has any of its keys
1497 marked as readonly and the key is subsequently deleted, the key is not actually
1498 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1499 it so it will be ignored by future operations such as iterating over the hash,
1500 but will still allow the hash to have a value reassigned to the key at some
1501 future point. This function clears any such placeholder keys from the hash.
1502 See Hash::Util::lock_keys() for an example of its use.
1508 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1511 I32 items = (I32)HvPLACEHOLDERS(hv);
1518 /* Loop down the linked list heads */
1520 HE **oentry = &(HvARRAY(hv))[i];
1521 HE *entry = *oentry;
1526 for (; entry; entry = *oentry) {
1527 if (HeVAL(entry) == &PL_sv_placeholder) {
1528 *oentry = HeNEXT(entry);
1529 if (first && !*oentry)
1530 HvFILL(hv)--; /* This linked list is now empty. */
1534 hv_free_ent(hv, entry);
1538 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS(hv);
1539 if (HvKEYS(hv) == 0)
1540 HvHASKFLAGS_off(hv);
1541 HvPLACEHOLDERS(hv) = 0;
1545 oentry = &HeNEXT(entry);
1550 /* You can't get here, hence assertion should always fail. */
1551 assert (items == 0);
1556 S_hfreeentries(pTHX_ HV *hv)
1558 register HE **array;
1560 register HE *oentry = Null(HE*);
1571 array = HvARRAY(hv);
1572 /* make everyone else think the array is empty, so that the destructors
1573 * called for freed entries can't recusively mess with us */
1574 HvARRAY(hv) = Null(HE**);
1576 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1582 entry = HeNEXT(entry);
1583 hv_free_ent(hv, oentry);
1588 entry = array[riter];
1591 HvARRAY(hv) = array;
1592 (void)hv_iterinit(hv);
1596 =for apidoc hv_undef
1604 Perl_hv_undef(pTHX_ HV *hv)
1606 register XPVHV* xhv;
1609 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1610 xhv = (XPVHV*)SvANY(hv);
1612 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1615 hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD);
1616 Safefree(HvNAME(hv));
1619 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1620 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
1621 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1628 =for apidoc hv_iterinit
1630 Prepares a starting point to traverse a hash table. Returns the number of
1631 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1632 currently only meaningful for hashes without tie magic.
1634 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1635 hash buckets that happen to be in use. If you still need that esoteric
1636 value, you can get it through the macro C<HvFILL(tb)>.
1643 Perl_hv_iterinit(pTHX_ HV *hv)
1645 register XPVHV* xhv;
1649 Perl_croak(aTHX_ "Bad hash");
1650 xhv = (XPVHV*)SvANY(hv);
1651 entry = xhv->xhv_eiter; /* HvEITER(hv) */
1652 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1654 hv_free_ent(hv, entry);
1656 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1657 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1658 /* used to be xhv->xhv_fill before 5.004_65 */
1659 return XHvTOTALKEYS(xhv);
1662 =for apidoc hv_iternext
1664 Returns entries from a hash iterator. See C<hv_iterinit>.
1666 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1667 iterator currently points to, without losing your place or invalidating your
1668 iterator. Note that in this case the current entry is deleted from the hash
1669 with your iterator holding the last reference to it. Your iterator is flagged
1670 to free the entry on the next call to C<hv_iternext>, so you must not discard
1671 your iterator immediately else the entry will leak - call C<hv_iternext> to
1672 trigger the resource deallocation.
1678 Perl_hv_iternext(pTHX_ HV *hv)
1680 return hv_iternext_flags(hv, 0);
1684 =for apidoc hv_iternext_flags
1686 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1687 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1688 set the placeholders keys (for restricted hashes) will be returned in addition
1689 to normal keys. By default placeholders are automatically skipped over.
1690 Currently a placeholder is implemented with a value that is
1691 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1692 restricted hashes may change, and the implementation currently is
1693 insufficiently abstracted for any change to be tidy.
1699 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1702 register XPVHV* xhv;
1708 Perl_croak(aTHX_ "Bad hash");
1709 xhv = (XPVHV*)SvANY(hv);
1710 oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */
1712 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1713 SV *key = sv_newmortal();
1715 sv_setsv(key, HeSVKEY_force(entry));
1716 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1722 /* one HE per MAGICAL hash */
1723 xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1725 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1727 HeKEY_hek(entry) = hek;
1728 HeKLEN(entry) = HEf_SVKEY;
1730 magic_nextpack((SV*) hv,mg,key);
1732 /* force key to stay around until next time */
1733 HeSVKEY_set(entry, SvREFCNT_inc(key));
1734 return entry; /* beware, hent_val is not set */
1737 SvREFCNT_dec(HeVAL(entry));
1738 Safefree(HeKEY_hek(entry));
1740 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1743 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1744 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1748 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1749 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
1750 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1752 /* At start of hash, entry is NULL. */
1755 entry = HeNEXT(entry);
1756 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1758 * Skip past any placeholders -- don't want to include them in
1761 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1762 entry = HeNEXT(entry);
1767 /* OK. Come to the end of the current list. Grab the next one. */
1769 xhv->xhv_riter++; /* HvRITER(hv)++ */
1770 if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1771 /* There is no next one. End of the hash. */
1772 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1775 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
1776 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
1778 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1779 /* If we have an entry, but it's a placeholder, don't count it.
1781 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1782 entry = HeNEXT(entry);
1784 /* Will loop again if this linked list starts NULL
1785 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1786 or if we run through it and find only placeholders. */
1789 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1791 hv_free_ent(hv, oldentry);
1794 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1795 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1797 xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */
1802 =for apidoc hv_iterkey
1804 Returns the key from the current position of the hash iterator. See
1811 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1813 if (HeKLEN(entry) == HEf_SVKEY) {
1815 char *p = SvPV(HeKEY_sv(entry), len);
1820 *retlen = HeKLEN(entry);
1821 return HeKEY(entry);
1825 /* unlike hv_iterval(), this always returns a mortal copy of the key */
1827 =for apidoc hv_iterkeysv
1829 Returns the key as an C<SV*> from the current position of the hash
1830 iterator. The return value will always be a mortal copy of the key. Also
1837 Perl_hv_iterkeysv(pTHX_ register HE *entry)
1839 if (HeKLEN(entry) != HEf_SVKEY) {
1840 HEK *hek = HeKEY_hek(entry);
1841 int flags = HEK_FLAGS(hek);
1844 if (flags & HVhek_WASUTF8) {
1846 Andreas would like keys he put in as utf8 to come back as utf8
1848 STRLEN utf8_len = HEK_LEN(hek);
1849 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
1851 sv = newSVpvn ((char*)as_utf8, utf8_len);
1853 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
1854 } else if (flags & HVhek_REHASH) {
1855 /* We don't have a pointer to the hv, so we have to replicate the
1856 flag into every HEK. This hv is using custom a hasing
1857 algorithm. Hence we can't return a shared string scalar, as
1858 that would contain the (wrong) hash value, and might get passed
1859 into an hv routine with a regular hash */
1861 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
1865 sv = newSVpvn_share(HEK_KEY(hek),
1866 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
1869 return sv_2mortal(sv);
1871 return sv_mortalcopy(HeKEY_sv(entry));
1875 =for apidoc hv_iterval
1877 Returns the value from the current position of the hash iterator. See
1884 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
1886 if (SvRMAGICAL(hv)) {
1887 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
1888 SV* sv = sv_newmortal();
1889 if (HeKLEN(entry) == HEf_SVKEY)
1890 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
1891 else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
1895 return HeVAL(entry);
1899 =for apidoc hv_iternextsv
1901 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
1908 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
1911 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
1913 *key = hv_iterkey(he, retlen);
1914 return hv_iterval(hv, he);
1918 =for apidoc hv_magic
1920 Adds magic to a hash. See C<sv_magic>.
1926 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
1928 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
1931 #if 0 /* use the macro from hv.h instead */
1934 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
1936 return HEK_KEY(share_hek(sv, len, hash));
1941 /* possibly free a shared string if no one has access to it
1942 * len and hash must both be valid for str.
1945 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
1947 unshare_hek_or_pvn (NULL, str, len, hash);
1952 Perl_unshare_hek(pTHX_ HEK *hek)
1954 unshare_hek_or_pvn(hek, NULL, 0, 0);
1957 /* possibly free a shared string if no one has access to it
1958 hek if non-NULL takes priority over the other 3, else str, len and hash
1959 are used. If so, len and hash must both be valid for str.
1962 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
1964 register XPVHV* xhv;
1966 register HE **oentry;
1969 bool is_utf8 = FALSE;
1971 const char *save = str;
1974 hash = HEK_HASH(hek);
1975 } else if (len < 0) {
1976 STRLEN tmplen = -len;
1978 /* See the note in hv_fetch(). --jhi */
1979 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
1982 k_flags = HVhek_UTF8;
1984 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1987 /* what follows is the moral equivalent of:
1988 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
1989 if (--*Svp == Nullsv)
1990 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
1992 xhv = (XPVHV*)SvANY(PL_strtab);
1993 /* assert(xhv_array != 0) */
1995 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1996 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
1998 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
1999 if (HeKEY_hek(entry) != hek)
2005 const int flags_masked = k_flags & HVhek_MASK;
2006 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2007 if (HeHASH(entry) != hash) /* strings can't be equal */
2009 if (HeKLEN(entry) != len)
2011 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2013 if (HeKFLAGS(entry) != flags_masked)
2021 if (--HeVAL(entry) == Nullsv) {
2022 *oentry = HeNEXT(entry);
2024 xhv->xhv_fill--; /* HvFILL(hv)-- */
2025 Safefree(HeKEY_hek(entry));
2027 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2031 UNLOCK_STRTAB_MUTEX;
2032 if (!found && ckWARN_d(WARN_INTERNAL))
2033 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2034 "Attempt to free non-existent shared string '%s'%s"
2036 hek ? HEK_KEY(hek) : str,
2037 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2038 if (k_flags & HVhek_FREEKEY)
2042 /* get a (constant) string ptr from the global string table
2043 * string will get added if it is not already there.
2044 * len and hash must both be valid for str.
2047 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2049 bool is_utf8 = FALSE;
2051 const char *save = str;
2054 STRLEN tmplen = -len;
2056 /* See the note in hv_fetch(). --jhi */
2057 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2059 /* If we were able to downgrade here, then than means that we were passed
2060 in a key which only had chars 0-255, but was utf8 encoded. */
2063 /* If we found we were able to downgrade the string to bytes, then
2064 we should flag that it needs upgrading on keys or each. Also flag
2065 that we need share_hek_flags to free the string. */
2067 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2070 return share_hek_flags (str, len, hash, flags);
2074 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2076 register XPVHV* xhv;
2078 register HE **oentry;
2081 const int flags_masked = flags & HVhek_MASK;
2083 /* what follows is the moral equivalent of:
2085 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2086 hv_store(PL_strtab, str, len, Nullsv, hash);
2088 Can't rehash the shared string table, so not sure if it's worth
2089 counting the number of entries in the linked list
2091 xhv = (XPVHV*)SvANY(PL_strtab);
2092 /* assert(xhv_array != 0) */
2094 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2095 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2096 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2097 if (HeHASH(entry) != hash) /* strings can't be equal */
2099 if (HeKLEN(entry) != len)
2101 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2103 if (HeKFLAGS(entry) != flags_masked)
2110 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2111 HeVAL(entry) = Nullsv;
2112 HeNEXT(entry) = *oentry;
2114 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2115 if (i) { /* initial entry? */
2116 xhv->xhv_fill++; /* HvFILL(hv)++ */
2117 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2122 ++HeVAL(entry); /* use value slot as REFCNT */
2123 UNLOCK_STRTAB_MUTEX;
2125 if (flags & HVhek_FREEKEY)
2128 return HeKEY_hek(entry);
2133 =for apidoc hv_assert
2135 Check that a hash is in an internally consistent state.
2141 Perl_hv_assert(pTHX_ HV *hv)
2146 int placeholders = 0;
2149 I32 riter = HvRITER(hv);
2150 HE *eiter = HvEITER(hv);
2152 (void)hv_iterinit(hv);
2154 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2155 /* sanity check the values */
2156 if (HeVAL(entry) == &PL_sv_placeholder) {
2161 /* sanity check the keys */
2162 if (HeSVKEY(entry)) {
2163 /* Don't know what to check on SV keys. */
2164 } else if (HeKUTF8(entry)) {
2166 if (HeKWASUTF8(entry)) {
2167 PerlIO_printf(Perl_debug_log,
2168 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2169 (int) HeKLEN(entry), HeKEY(entry));
2172 } else if (HeKWASUTF8(entry)) {
2176 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2177 if (HvUSEDKEYS(hv) != real) {
2178 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2179 (int) real, (int) HvUSEDKEYS(hv));
2182 if (HvPLACEHOLDERS(hv) != placeholders) {
2183 PerlIO_printf(Perl_debug_log,
2184 "Count %d placeholder(s), but hash reports %d\n",
2185 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2189 if (withflags && ! HvHASKFLAGS(hv)) {
2190 PerlIO_printf(Perl_debug_log,
2191 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2198 HvRITER(hv) = riter; /* Restore hash iterator state */
2199 HvEITER(hv) = eiter;
2204 * c-indentation-style: bsd
2206 * indent-tabs-mode: t
2209 * vim: shiftwidth=4: