3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
44 PL_he_root = HeNEXT(he);
53 HeNEXT(p) = (HE*)PL_he_root;
64 New(54, ptr, 1008/sizeof(XPV), XPV);
65 ptr->xpv_pv = (char*)PL_he_arenaroot;
66 PL_he_arenaroot = ptr;
69 heend = &he[1008 / sizeof(HE) - 1];
72 HeNEXT(he) = (HE*)(he + 1);
80 #define new_HE() (HE*)safemalloc(sizeof(HE))
81 #define del_HE(p) safefree((char*)p)
85 #define new_HE() new_he()
86 #define del_HE(p) del_he(p)
91 S_save_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
93 int flags_masked = flags & HVhek_MASK;
97 New(54, k, HEK_BASESIZE + len + 2, char);
99 Copy(str, HEK_KEY(hek), len, char);
100 HEK_KEY(hek)[len] = 0;
102 HEK_HASH(hek) = hash;
103 HEK_FLAGS(hek) = (unsigned char)flags_masked;
105 if (flags & HVhek_FREEKEY)
110 /* free the pool of temporary HE/HEK pairs retunrned by hv_fetch_ent
114 Perl_free_tied_hv_pool(pTHX)
117 HE *he = PL_hv_fetch_ent_mh;
119 Safefree(HeKEY_hek(he));
124 PL_hv_fetch_ent_mh = Nullhe;
127 #if defined(USE_ITHREADS)
129 Perl_he_dup(pTHX_ HE *e, bool shared, CLONE_PARAMS* param)
135 /* look for it in the table first */
136 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
140 /* create anew and remember what it is */
142 ptr_table_store(PL_ptr_table, e, ret);
144 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
145 if (HeKLEN(e) == HEf_SVKEY) {
147 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
148 HeKEY_hek(ret) = (HEK*)k;
149 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
152 HeKEY_hek(ret) = share_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
155 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
157 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
160 #endif /* USE_ITHREADS */
163 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
166 SV *sv = sv_newmortal(), *esv = sv_newmortal();
167 if (!(flags & HVhek_FREEKEY)) {
168 sv_setpvn(sv, key, klen);
171 /* Need to free saved eventually assign to mortal SV */
172 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
173 sv_usepvn(sv, (char *) key, klen);
175 if (flags & HVhek_UTF8) {
178 Perl_sv_setpvf(aTHX_ esv, "Attempt to %s a restricted hash", msg);
179 Perl_croak(aTHX_ SvPVX(esv), sv);
182 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
185 #define HV_FETCH_ISSTORE 0x01
186 #define HV_FETCH_ISEXISTS 0x02
187 #define HV_FETCH_LVALUE 0x04
188 #define HV_FETCH_JUST_SV 0x08
193 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
194 the length of the key. The C<hash> parameter is the precomputed hash
195 value; if it is zero then Perl will compute it. The return value will be
196 NULL if the operation failed or if the value did not need to be actually
197 stored within the hash (as in the case of tied hashes). Otherwise it can
198 be dereferenced to get the original C<SV*>. Note that the caller is
199 responsible for suitably incrementing the reference count of C<val> before
200 the call, and decrementing it if the function returned NULL. Effectively
201 a successful hv_store takes ownership of one reference to C<val>. This is
202 usually what you want; a newly created SV has a reference count of one, so
203 if all your code does is create SVs then store them in a hash, hv_store
204 will own the only reference to the new SV, and your code doesn't need to do
205 anything further to tidy up. hv_store is not implemented as a call to
206 hv_store_ent, and does not create a temporary SV for the key, so if your
207 key data is not already in SV form then use hv_store in preference to
210 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
211 information on how to use this function on tied hashes.
217 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
230 hek = hv_fetch_common (hv, NULL, key, klen, flags,
231 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
232 return hek ? &HeVAL(hek) : NULL;
236 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
237 register U32 hash, int flags)
239 HE *hek = hv_fetch_common (hv, NULL, key, klen, flags,
240 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
241 return hek ? &HeVAL(hek) : NULL;
245 =for apidoc hv_store_ent
247 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
248 parameter is the precomputed hash value; if it is zero then Perl will
249 compute it. The return value is the new hash entry so created. It will be
250 NULL if the operation failed or if the value did not need to be actually
251 stored within the hash (as in the case of tied hashes). Otherwise the
252 contents of the return value can be accessed using the C<He?> macros
253 described here. Note that the caller is responsible for suitably
254 incrementing the reference count of C<val> before the call, and
255 decrementing it if the function returned NULL. Effectively a successful
256 hv_store_ent takes ownership of one reference to C<val>. This is
257 usually what you want; a newly created SV has a reference count of one, so
258 if all your code does is create SVs then store them in a hash, hv_store
259 will own the only reference to the new SV, and your code doesn't need to do
260 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
261 unlike C<val> it does not take ownership of it, so maintaining the correct
262 reference count on C<key> is entirely the caller's responsibility. hv_store
263 is not implemented as a call to hv_store_ent, and does not create a temporary
264 SV for the key, so if your key data is not already in SV form then use
265 hv_store in preference to hv_store_ent.
267 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
268 information on how to use this function on tied hashes.
274 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
276 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
280 =for apidoc hv_exists
282 Returns a boolean indicating whether the specified hash key exists. The
283 C<klen> is the length of the key.
289 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
301 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
308 Returns the SV which corresponds to the specified key in the hash. The
309 C<klen> is the length of the key. If C<lval> is set then the fetch will be
310 part of a store. Check that the return value is non-null before
311 dereferencing it to an C<SV*>.
313 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
314 information on how to use this function on tied hashes.
320 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
333 hek = hv_fetch_common (hv, NULL, key, klen, flags,
334 HV_FETCH_JUST_SV | (lval ? HV_FETCH_LVALUE : 0),
336 return hek ? &HeVAL(hek) : NULL;
340 =for apidoc hv_exists_ent
342 Returns a boolean indicating whether the specified hash key exists. C<hash>
343 can be a valid precomputed hash value, or 0 to ask for it to be
350 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
352 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
356 /* returns an HE * structure with the all fields set */
357 /* note that hent_val will be a mortal sv for MAGICAL hashes */
359 =for apidoc hv_fetch_ent
361 Returns the hash entry which corresponds to the specified key in the hash.
362 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
363 if you want the function to compute it. IF C<lval> is set then the fetch
364 will be part of a store. Make sure the return value is non-null before
365 accessing it. The return value when C<tb> is a tied hash is a pointer to a
366 static location, so be sure to make a copy of the structure if you need to
369 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
370 information on how to use this function on tied hashes.
376 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
378 return hv_fetch_common(hv, keysv, NULL, 0, 0,
379 (lval ? HV_FETCH_LVALUE : 0), Nullsv, hash);
383 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
384 int flags, int action, SV *val, register U32 hash)
398 if (flags & HVhek_FREEKEY)
400 key = SvPV(keysv, klen);
402 is_utf8 = (SvUTF8(keysv) != 0);
404 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
407 xhv = (XPVHV*)SvANY(hv);
409 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS)))
411 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
414 /* XXX should be able to skimp on the HE/HEK here when
415 HV_FETCH_JUST_SV is true. */
418 keysv = newSVpvn(key, klen);
423 keysv = newSVsv(keysv);
425 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
427 /* grab a fake HE/HEK pair from the pool or make a new one */
428 entry = PL_hv_fetch_ent_mh;
430 PL_hv_fetch_ent_mh = HeNEXT(entry);
434 New(54, k, HEK_BASESIZE + sizeof(SV*), char);
435 HeKEY_hek(entry) = (HEK*)k;
437 HeNEXT(entry) = Nullhe;
438 HeSVKEY_set(entry, keysv);
440 sv_upgrade(sv, SVt_PVLV);
442 /* so we can free entry when freeing sv */
443 LvTARG(sv) = (SV*)entry;
445 /* XXX remove at some point? */
446 if (flags & HVhek_FREEKEY)
451 #ifdef ENV_IS_CASELESS
452 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
454 for (i = 0; i < klen; ++i)
455 if (isLOWER(key[i])) {
456 /* Would be nice if we had a routine to do the
457 copy and upercase in a single pass through. */
458 char *nkey = strupr(savepvn(key,klen));
459 /* Note that this fetch is for nkey (the uppercased
460 key) whereas the store is for key (the original) */
461 entry = hv_fetch_common(hv, Nullsv, nkey, klen,
462 HVhek_FREEKEY, /* free nkey */
463 0 /* non-LVAL fetch */,
464 Nullsv /* no value */,
465 0 /* compute hash */);
466 if (!entry && (action & HV_FETCH_LVALUE)) {
467 /* This call will free key if necessary.
468 Do it this way to encourage compiler to tail
470 entry = hv_fetch_common(hv, keysv, key, klen,
471 flags, HV_FETCH_ISSTORE,
474 if (flags & HVhek_FREEKEY)
482 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
483 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
485 /* I don't understand why hv_exists_ent has svret and sv,
486 whereas hv_exists only had one. */
487 svret = sv_newmortal();
490 if (keysv || is_utf8) {
492 keysv = newSVpvn(key, klen);
495 keysv = newSVsv(keysv);
497 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
499 mg_copy((SV*)hv, sv, key, klen);
501 if (flags & HVhek_FREEKEY)
503 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
504 /* This cast somewhat evil, but I'm merely using NULL/
505 not NULL to return the boolean exists.
506 And I know hv is not NULL. */
507 return SvTRUE(svret) ? (HE *)hv : NULL;
509 #ifdef ENV_IS_CASELESS
510 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
511 /* XXX This code isn't UTF8 clean. */
512 const char *keysave = key;
513 /* Will need to free this, so set FREEKEY flag. */
514 key = savepvn(key,klen);
515 key = (const char*)strupr((char*)key);
520 if (flags & HVhek_FREEKEY) {
523 flags |= HVhek_FREEKEY;
527 else if (action & HV_FETCH_ISSTORE) {
530 hv_magic_check (hv, &needs_copy, &needs_store);
532 bool save_taint = PL_tainted;
533 if (keysv || is_utf8) {
535 keysv = newSVpvn(key, klen);
539 PL_tainted = SvTAINTED(keysv);
540 keysv = sv_2mortal(newSVsv(keysv));
541 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
543 mg_copy((SV*)hv, val, key, klen);
546 TAINT_IF(save_taint);
547 if (!xhv->xhv_array /* !HvARRAY(hv) */ && !needs_store) {
548 if (flags & HVhek_FREEKEY)
552 #ifdef ENV_IS_CASELESS
553 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
554 /* XXX This code isn't UTF8 clean. */
555 const char *keysave = key;
556 /* Will need to free this, so set FREEKEY flag. */
557 key = savepvn(key,klen);
558 key = (const char*)strupr((char*)key);
563 if (flags & HVhek_FREEKEY) {
566 flags |= HVhek_FREEKEY;
573 if (!xhv->xhv_array /* !HvARRAY(hv) */) {
574 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
575 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
576 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
579 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
580 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
582 #ifdef DYNAMIC_ENV_FETCH
583 else if (action & HV_FETCH_ISEXISTS) {
584 /* for an %ENV exists, if we do an insert it's by a recursive
585 store call, so avoid creating HvARRAY(hv) right now. */
589 /* XXX remove at some point? */
590 if (flags & HVhek_FREEKEY)
598 const char *keysave = key;
599 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
603 flags &= ~HVhek_UTF8;
604 if (key != keysave) {
605 if (flags & HVhek_FREEKEY)
607 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
612 PERL_HASH_INTERNAL(hash, key, klen);
613 /* We don't have a pointer to the hv, so we have to replicate the
614 flag into every HEK, so that hv_iterkeysv can see it. */
615 /* And yes, you do need this even though you are not "storing" because
616 you can flip the flags below if doing an lval lookup. (And that
617 was put in to give the semantics Andreas was expecting.) */
618 flags |= HVhek_REHASH;
620 if (keysv && (SvIsCOW_shared_hash(keysv))) {
623 PERL_HASH(hash, key, klen);
627 masked_flags = (flags & HVhek_MASK);
630 #ifdef DYNAMIC_ENV_FETCH
631 if (!xhv->xhv_array /* !HvARRAY(hv) */) entry = Null(HE*);
635 /* entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
636 entry = ((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
638 for (; entry; ++n_links, entry = HeNEXT(entry)) {
639 if (HeHASH(entry) != hash) /* strings can't be equal */
641 if (HeKLEN(entry) != (I32)klen)
643 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
645 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
648 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
649 if (HeKFLAGS(entry) != masked_flags) {
650 /* We match if HVhek_UTF8 bit in our flags and hash key's
651 match. But if entry was set previously with HVhek_WASUTF8
652 and key now doesn't (or vice versa) then we should change
653 the key's flag, as this is assignment. */
654 if (HvSHAREKEYS(hv)) {
655 /* Need to swap the key we have for a key with the flags we
656 need. As keys are shared we can't just write to the
657 flag, so we share the new one, unshare the old one. */
658 HEK *new_hek = share_hek_flags(key, klen, hash,
660 unshare_hek (HeKEY_hek(entry));
661 HeKEY_hek(entry) = new_hek;
664 HeKFLAGS(entry) = masked_flags;
665 if (masked_flags & HVhek_ENABLEHVKFLAGS)
668 if (HeVAL(entry) == &PL_sv_placeholder) {
669 /* yes, can store into placeholder slot */
670 if (action & HV_FETCH_LVALUE) {
672 /* This preserves behaviour with the old hv_fetch
673 implementation which at this point would bail out
674 with a break; (at "if we find a placeholder, we
675 pretend we haven't found anything")
677 That break mean that if a placeholder were found, it
678 caused a call into hv_store, which in turn would
679 check magic, and if there is no magic end up pretty
680 much back at this point (in hv_store's code). */
683 /* LVAL fetch which actaully needs a store. */
685 xhv->xhv_placeholders--;
688 if (val != &PL_sv_placeholder)
689 xhv->xhv_placeholders--;
692 } else if (action & HV_FETCH_ISSTORE) {
693 SvREFCNT_dec(HeVAL(entry));
696 } else if (HeVAL(entry) == &PL_sv_placeholder) {
697 /* if we find a placeholder, we pretend we haven't found
701 if (flags & HVhek_FREEKEY)
705 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
706 if (!(action & HV_FETCH_ISSTORE)
707 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
709 char *env = PerlEnv_ENVgetenv_len(key,&len);
711 sv = newSVpvn(env,len);
713 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
719 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
720 S_hv_notallowed(aTHX_ flags, key, klen,
721 "access disallowed key '%"SVf"' in"
724 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
725 /* Not doing some form of store, so return failure. */
726 if (flags & HVhek_FREEKEY)
730 if (action & HV_FETCH_LVALUE) {
733 /* At this point the old hv_fetch code would call to hv_store,
734 which in turn might do some tied magic. So we need to make that
735 magic check happen. */
736 /* gonna assign to this, so it better be there */
737 return hv_fetch_common(hv, keysv, key, klen, flags,
738 HV_FETCH_ISSTORE, val, hash);
739 /* XXX Surely that could leak if the fetch-was-store fails?
740 Just like the hv_fetch. */
744 /* Welcome to hv_store... */
746 if (!xhv->xhv_array) {
747 /* Not sure if we can get here. I think the only case of oentry being
748 NULL is for %ENV with dynamic env fetch. But that should disappear
749 with magic in the previous code. */
750 Newz(503, xhv->xhv_array /* HvARRAY(hv) */,
751 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
755 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
758 /* share_hek_flags will do the free for us. This might be considered
761 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
762 else /* gotta do the real thing */
763 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
765 HeNEXT(entry) = *oentry;
768 if (val == &PL_sv_placeholder)
769 xhv->xhv_placeholders++;
770 if (masked_flags & HVhek_ENABLEHVKFLAGS)
773 xhv->xhv_keys++; /* HvKEYS(hv)++ */
774 if (!n_links) { /* initial entry? */
775 xhv->xhv_fill++; /* HvFILL(hv)++ */
776 } else if ((xhv->xhv_keys > (IV)xhv->xhv_max)
777 || ((n_links > HV_MAX_LENGTH_BEFORE_SPLIT) && !HvREHASH(hv))) {
778 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit bucket
779 splits on a rehashed hash, as we're not going to split it again,
780 and if someone is lucky (evil) enough to get all the keys in one
781 list they could exhaust our memory as we repeatedly double the
782 number of buckets on every entry. Linear search feels a less worse
791 S_hv_magic_check(pTHX_ HV *hv, bool *needs_copy, bool *needs_store)
793 MAGIC *mg = SvMAGIC(hv);
797 if (isUPPER(mg->mg_type)) {
799 switch (mg->mg_type) {
800 case PERL_MAGIC_tied:
802 *needs_store = FALSE;
805 mg = mg->mg_moremagic;
810 =for apidoc hv_scalar
812 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
818 Perl_hv_scalar(pTHX_ HV *hv)
823 if ((SvRMAGICAL(hv) && (mg = mg_find((SV*)hv, PERL_MAGIC_tied)))) {
824 sv = magic_scalarpack(hv, mg);
830 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
831 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
839 =for apidoc hv_delete
841 Deletes a key/value pair in the hash. The value SV is removed from the
842 hash and returned to the caller. The C<klen> is the length of the key.
843 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
850 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
857 k_flags |= HVhek_UTF8;
861 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
865 =for apidoc hv_delete_ent
867 Deletes a key/value pair in the hash. The value SV is removed from the
868 hash and returned to the caller. The C<flags> value will normally be zero;
869 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
870 precomputed hash value, or 0 to ask for it to be computed.
876 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
878 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
882 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
883 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)
1445 register XPVHV* xhv;
1449 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1451 xhv = (XPVHV*)SvANY(hv);
1453 if (SvREADONLY(hv) && xhv->xhv_array != NULL) {
1454 /* restricted hash: convert all keys to placeholders */
1457 for (i = 0; i <= (I32) xhv->xhv_max; i++) {
1458 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 xhv->xhv_placeholders++; /* HvPLACEHOLDERS(hv)++ */
1478 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(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);
1493 =for apidoc hv_clear_placeholders
1495 Clears any placeholders from a hash. If a restricted hash has any of its keys
1496 marked as readonly and the key is subsequently deleted, the key is not actually
1497 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1498 it so it will be ignored by future operations such as iterating over the hash,
1499 but will still allow the hash to have a value reassigned to the key at some
1500 future point. This function clears any such placeholder keys from the hash.
1501 See Hash::Util::lock_keys() for an example of its use.
1507 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1509 I32 items = (I32)HvPLACEHOLDERS(hv);
1516 /* Loop down the linked list heads */
1518 HE **oentry = &(HvARRAY(hv))[i];
1519 HE *entry = *oentry;
1524 for (; entry; entry = *oentry) {
1525 if (HeVAL(entry) == &PL_sv_placeholder) {
1526 *oentry = HeNEXT(entry);
1527 if (first && !*oentry)
1528 HvFILL(hv)--; /* This linked list is now empty. */
1532 hv_free_ent(hv, entry);
1536 HvTOTALKEYS(hv) -= HvPLACEHOLDERS(hv);
1537 if (HvKEYS(hv) == 0)
1538 HvHASKFLAGS_off(hv);
1539 HvPLACEHOLDERS(hv) = 0;
1543 oentry = &HeNEXT(entry);
1548 /* You can't get here, hence assertion should always fail. */
1549 assert (items == 0);
1554 S_hfreeentries(pTHX_ HV *hv)
1556 register HE **array;
1558 register HE *oentry = Null(HE*);
1569 array = HvARRAY(hv);
1570 /* make everyone else think the array is empty, so that the destructors
1571 * called for freed entries can't recusively mess with us */
1572 HvARRAY(hv) = Null(HE**);
1574 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1580 entry = HeNEXT(entry);
1581 hv_free_ent(hv, oentry);
1586 entry = array[riter];
1589 HvARRAY(hv) = array;
1590 (void)hv_iterinit(hv);
1594 =for apidoc hv_undef
1602 Perl_hv_undef(pTHX_ HV *hv)
1604 register XPVHV* xhv;
1607 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1608 xhv = (XPVHV*)SvANY(hv);
1610 Safefree(xhv->xhv_array /* HvARRAY(hv) */);
1613 hv_delete(PL_stashcache, HvNAME(hv), strlen(HvNAME(hv)), G_DISCARD);
1614 Safefree(HvNAME(hv));
1617 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1618 xhv->xhv_array = 0; /* HvARRAY(hv) = 0 */
1619 xhv->xhv_placeholders = 0; /* HvPLACEHOLDERS(hv) = 0 */
1626 =for apidoc hv_iterinit
1628 Prepares a starting point to traverse a hash table. Returns the number of
1629 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1630 currently only meaningful for hashes without tie magic.
1632 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1633 hash buckets that happen to be in use. If you still need that esoteric
1634 value, you can get it through the macro C<HvFILL(tb)>.
1641 Perl_hv_iterinit(pTHX_ HV *hv)
1643 register XPVHV* xhv;
1647 Perl_croak(aTHX_ "Bad hash");
1648 xhv = (XPVHV*)SvANY(hv);
1649 entry = xhv->xhv_eiter; /* HvEITER(hv) */
1650 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1652 hv_free_ent(hv, entry);
1654 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1655 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1656 /* used to be xhv->xhv_fill before 5.004_65 */
1657 return XHvTOTALKEYS(xhv);
1660 =for apidoc hv_iternext
1662 Returns entries from a hash iterator. See C<hv_iterinit>.
1664 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1665 iterator currently points to, without losing your place or invalidating your
1666 iterator. Note that in this case the current entry is deleted from the hash
1667 with your iterator holding the last reference to it. Your iterator is flagged
1668 to free the entry on the next call to C<hv_iternext>, so you must not discard
1669 your iterator immediately else the entry will leak - call C<hv_iternext> to
1670 trigger the resource deallocation.
1676 Perl_hv_iternext(pTHX_ HV *hv)
1678 return hv_iternext_flags(hv, 0);
1682 =for apidoc hv_iternext_flags
1684 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1685 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1686 set the placeholders keys (for restricted hashes) will be returned in addition
1687 to normal keys. By default placeholders are automatically skipped over.
1688 Currently a placeholder is implemented with a value that is
1689 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1690 restricted hashes may change, and the implementation currently is
1691 insufficiently abstracted for any change to be tidy.
1697 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1699 register XPVHV* xhv;
1705 Perl_croak(aTHX_ "Bad hash");
1706 xhv = (XPVHV*)SvANY(hv);
1707 oldentry = entry = xhv->xhv_eiter; /* HvEITER(hv) */
1709 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
1710 SV *key = sv_newmortal();
1712 sv_setsv(key, HeSVKEY_force(entry));
1713 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
1719 /* one HE per MAGICAL hash */
1720 xhv->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
1722 Newz(54, k, HEK_BASESIZE + sizeof(SV*), char);
1724 HeKEY_hek(entry) = hek;
1725 HeKLEN(entry) = HEf_SVKEY;
1727 magic_nextpack((SV*) hv,mg,key);
1729 /* force key to stay around until next time */
1730 HeSVKEY_set(entry, SvREFCNT_inc(key));
1731 return entry; /* beware, hent_val is not set */
1734 SvREFCNT_dec(HeVAL(entry));
1735 Safefree(HeKEY_hek(entry));
1737 xhv->xhv_eiter = Null(HE*); /* HvEITER(hv) = Null(HE*) */
1740 #ifdef DYNAMIC_ENV_FETCH /* set up %ENV for iteration */
1741 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
1745 if (!xhv->xhv_array /* !HvARRAY(hv) */)
1746 Newz(506, xhv->xhv_array /* HvARRAY(hv) */,
1747 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
1749 /* At start of hash, entry is NULL. */
1752 entry = HeNEXT(entry);
1753 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1755 * Skip past any placeholders -- don't want to include them in
1758 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
1759 entry = HeNEXT(entry);
1764 /* OK. Come to the end of the current list. Grab the next one. */
1766 xhv->xhv_riter++; /* HvRITER(hv)++ */
1767 if (xhv->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
1768 /* There is no next one. End of the hash. */
1769 xhv->xhv_riter = -1; /* HvRITER(hv) = -1 */
1772 /* entry = (HvARRAY(hv))[HvRITER(hv)]; */
1773 entry = ((HE**)xhv->xhv_array)[xhv->xhv_riter];
1775 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
1776 /* If we have an entry, but it's a placeholder, don't count it.
1778 while (entry && HeVAL(entry) == &PL_sv_placeholder)
1779 entry = HeNEXT(entry);
1781 /* Will loop again if this linked list starts NULL
1782 (for HV_ITERNEXT_WANTPLACEHOLDERS)
1783 or if we run through it and find only placeholders. */
1786 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1788 hv_free_ent(hv, oldentry);
1791 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
1792 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
1794 xhv->xhv_eiter = entry; /* HvEITER(hv) = entry */
1799 =for apidoc hv_iterkey
1801 Returns the key from the current position of the hash iterator. See
1808 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
1810 if (HeKLEN(entry) == HEf_SVKEY) {
1812 char *p = SvPV(HeKEY_sv(entry), len);
1817 *retlen = HeKLEN(entry);
1818 return HeKEY(entry);
1822 /* unlike hv_iterval(), this always returns a mortal copy of the key */
1824 =for apidoc hv_iterkeysv
1826 Returns the key as an C<SV*> from the current position of the hash
1827 iterator. The return value will always be a mortal copy of the key. Also
1834 Perl_hv_iterkeysv(pTHX_ register HE *entry)
1836 if (HeKLEN(entry) != HEf_SVKEY) {
1837 HEK *hek = HeKEY_hek(entry);
1838 int flags = HEK_FLAGS(hek);
1841 if (flags & HVhek_WASUTF8) {
1843 Andreas would like keys he put in as utf8 to come back as utf8
1845 STRLEN utf8_len = HEK_LEN(hek);
1846 U8 *as_utf8 = bytes_to_utf8 ((U8*)HEK_KEY(hek), &utf8_len);
1848 sv = newSVpvn ((char*)as_utf8, utf8_len);
1850 Safefree (as_utf8); /* bytes_to_utf8() allocates a new string */
1851 } else if (flags & HVhek_REHASH) {
1852 /* We don't have a pointer to the hv, so we have to replicate the
1853 flag into every HEK. This hv is using custom a hasing
1854 algorithm. Hence we can't return a shared string scalar, as
1855 that would contain the (wrong) hash value, and might get passed
1856 into an hv routine with a regular hash */
1858 sv = newSVpvn (HEK_KEY(hek), HEK_LEN(hek));
1862 sv = newSVpvn_share(HEK_KEY(hek),
1863 (HEK_UTF8(hek) ? -HEK_LEN(hek) : HEK_LEN(hek)),
1866 return sv_2mortal(sv);
1868 return sv_mortalcopy(HeKEY_sv(entry));
1872 =for apidoc hv_iterval
1874 Returns the value from the current position of the hash iterator. See
1881 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
1883 if (SvRMAGICAL(hv)) {
1884 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
1885 SV* sv = sv_newmortal();
1886 if (HeKLEN(entry) == HEf_SVKEY)
1887 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
1888 else mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
1892 return HeVAL(entry);
1896 =for apidoc hv_iternextsv
1898 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
1905 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
1908 if ( (he = hv_iternext_flags(hv, 0)) == NULL)
1910 *key = hv_iterkey(he, retlen);
1911 return hv_iterval(hv, he);
1915 =for apidoc hv_magic
1917 Adds magic to a hash. See C<sv_magic>.
1923 Perl_hv_magic(pTHX_ HV *hv, GV *gv, int how)
1925 sv_magic((SV*)hv, (SV*)gv, how, Nullch, 0);
1928 #if 0 /* use the macro from hv.h instead */
1931 Perl_sharepvn(pTHX_ const char *sv, I32 len, U32 hash)
1933 return HEK_KEY(share_hek(sv, len, hash));
1938 /* possibly free a shared string if no one has access to it
1939 * len and hash must both be valid for str.
1942 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
1944 unshare_hek_or_pvn (NULL, str, len, hash);
1949 Perl_unshare_hek(pTHX_ HEK *hek)
1951 unshare_hek_or_pvn(hek, NULL, 0, 0);
1954 /* possibly free a shared string if no one has access to it
1955 hek if non-NULL takes priority over the other 3, else str, len and hash
1956 are used. If so, len and hash must both be valid for str.
1959 S_unshare_hek_or_pvn(pTHX_ HEK *hek, const char *str, I32 len, U32 hash)
1961 register XPVHV* xhv;
1963 register HE **oentry;
1966 bool is_utf8 = FALSE;
1968 const char *save = str;
1971 hash = HEK_HASH(hek);
1972 } else if (len < 0) {
1973 STRLEN tmplen = -len;
1975 /* See the note in hv_fetch(). --jhi */
1976 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
1979 k_flags = HVhek_UTF8;
1981 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1984 /* what follows is the moral equivalent of:
1985 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
1986 if (--*Svp == Nullsv)
1987 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
1989 xhv = (XPVHV*)SvANY(PL_strtab);
1990 /* assert(xhv_array != 0) */
1992 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
1993 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
1995 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
1996 if (HeKEY_hek(entry) != hek)
2002 int flags_masked = k_flags & HVhek_MASK;
2003 for (entry = *oentry; entry; i=0, oentry = &HeNEXT(entry), entry = *oentry) {
2004 if (HeHASH(entry) != hash) /* strings can't be equal */
2006 if (HeKLEN(entry) != len)
2008 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2010 if (HeKFLAGS(entry) != flags_masked)
2018 if (--HeVAL(entry) == Nullsv) {
2019 *oentry = HeNEXT(entry);
2021 xhv->xhv_fill--; /* HvFILL(hv)-- */
2022 Safefree(HeKEY_hek(entry));
2024 xhv->xhv_keys--; /* HvKEYS(hv)-- */
2028 UNLOCK_STRTAB_MUTEX;
2029 if (!found && ckWARN_d(WARN_INTERNAL))
2030 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2031 "Attempt to free non-existent shared string '%s'%s"
2033 hek ? HEK_KEY(hek) : str,
2034 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2035 if (k_flags & HVhek_FREEKEY)
2039 /* get a (constant) string ptr from the global string table
2040 * string will get added if it is not already there.
2041 * len and hash must both be valid for str.
2044 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2046 bool is_utf8 = FALSE;
2048 const char *save = str;
2051 STRLEN tmplen = -len;
2053 /* See the note in hv_fetch(). --jhi */
2054 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2056 /* If we were able to downgrade here, then than means that we were passed
2057 in a key which only had chars 0-255, but was utf8 encoded. */
2060 /* If we found we were able to downgrade the string to bytes, then
2061 we should flag that it needs upgrading on keys or each. Also flag
2062 that we need share_hek_flags to free the string. */
2064 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2067 return share_hek_flags (str, len, hash, flags);
2071 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2073 register XPVHV* xhv;
2075 register HE **oentry;
2078 int flags_masked = flags & HVhek_MASK;
2080 /* what follows is the moral equivalent of:
2082 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2083 hv_store(PL_strtab, str, len, Nullsv, hash);
2085 Can't rehash the shared string table, so not sure if it's worth
2086 counting the number of entries in the linked list
2088 xhv = (XPVHV*)SvANY(PL_strtab);
2089 /* assert(xhv_array != 0) */
2091 /* oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)]; */
2092 oentry = &((HE**)xhv->xhv_array)[hash & (I32) xhv->xhv_max];
2093 for (entry = *oentry; entry; i=0, entry = HeNEXT(entry)) {
2094 if (HeHASH(entry) != hash) /* strings can't be equal */
2096 if (HeKLEN(entry) != len)
2098 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2100 if (HeKFLAGS(entry) != flags_masked)
2107 HeKEY_hek(entry) = save_hek_flags(str, len, hash, flags_masked);
2108 HeVAL(entry) = Nullsv;
2109 HeNEXT(entry) = *oentry;
2111 xhv->xhv_keys++; /* HvKEYS(hv)++ */
2112 if (i) { /* initial entry? */
2113 xhv->xhv_fill++; /* HvFILL(hv)++ */
2114 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2119 ++HeVAL(entry); /* use value slot as REFCNT */
2120 UNLOCK_STRTAB_MUTEX;
2122 if (flags & HVhek_FREEKEY)
2125 return HeKEY_hek(entry);
2130 =for apidoc hv_assert
2132 Check that a hash is in an internally consistent state.
2138 Perl_hv_assert(pTHX_ HV *hv)
2142 int placeholders = 0;
2145 I32 riter = HvRITER(hv);
2146 HE *eiter = HvEITER(hv);
2148 (void)hv_iterinit(hv);
2150 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2151 /* sanity check the values */
2152 if (HeVAL(entry) == &PL_sv_placeholder) {
2157 /* sanity check the keys */
2158 if (HeSVKEY(entry)) {
2159 /* Don't know what to check on SV keys. */
2160 } else if (HeKUTF8(entry)) {
2162 if (HeKWASUTF8(entry)) {
2163 PerlIO_printf(Perl_debug_log,
2164 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2165 (int) HeKLEN(entry), HeKEY(entry));
2168 } else if (HeKWASUTF8(entry)) {
2172 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2173 if (HvUSEDKEYS(hv) != real) {
2174 PerlIO_printf(Perl_debug_log, "Count %d key(s), but hash reports %d\n",
2175 (int) real, (int) HvUSEDKEYS(hv));
2178 if (HvPLACEHOLDERS(hv) != placeholders) {
2179 PerlIO_printf(Perl_debug_log,
2180 "Count %d placeholder(s), but hash reports %d\n",
2181 (int) placeholders, (int) HvPLACEHOLDERS(hv));
2185 if (withflags && ! HvHASKFLAGS(hv)) {
2186 PerlIO_printf(Perl_debug_log,
2187 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2194 HvRITER(hv) = riter; /* Restore hash iterator state */
2195 HvEITER(hv) = eiter;
2200 * c-indentation-style: bsd
2202 * indent-tabs-mode: t
2205 * vim: shiftwidth=4: