3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 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
36 static const char S_strtab_error[]
37 = "Cannot modify shared string table in hv_%s";
46 he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE);
48 heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
49 PL_body_roots[HE_SVSLOT] = he;
51 HeNEXT(he) = (HE*)(he + 1);
59 #define new_HE() (HE*)safemalloc(sizeof(HE))
60 #define del_HE(p) safefree((char*)p)
69 void ** const root = &PL_body_roots[HE_SVSLOT];
81 #define new_HE() new_he()
85 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
86 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 Newx(k, HEK_BASESIZE + len + 2, char);
103 Copy(str, HEK_KEY(hek), len, char);
104 HEK_KEY(hek)[len] = 0;
106 HEK_HASH(hek) = hash;
107 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
109 if (flags & HVhek_FREEKEY)
114 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
118 Perl_free_tied_hv_pool(pTHX)
121 HE *he = PL_hv_fetch_ent_mh;
124 Safefree(HeKEY_hek(he));
128 PL_hv_fetch_ent_mh = NULL;
131 #if defined(USE_ITHREADS)
133 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
135 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
137 PERL_UNUSED_ARG(param);
140 /* We already shared this hash key. */
141 (void)share_hek_hek(shared);
145 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
146 HEK_HASH(source), HEK_FLAGS(source));
147 ptr_table_store(PL_ptr_table, source, shared);
153 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
159 /* look for it in the table first */
160 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
164 /* create anew and remember what it is */
166 ptr_table_store(PL_ptr_table, e, ret);
168 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
169 if (HeKLEN(e) == HEf_SVKEY) {
171 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
172 HeKEY_hek(ret) = (HEK*)k;
173 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
176 /* This is hek_dup inlined, which seems to be important for speed
178 HEK * const source = HeKEY_hek(e);
179 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
182 /* We already shared this hash key. */
183 (void)share_hek_hek(shared);
187 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
188 HEK_HASH(source), HEK_FLAGS(source));
189 ptr_table_store(PL_ptr_table, source, shared);
191 HeKEY_hek(ret) = shared;
194 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
196 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
199 #endif /* USE_ITHREADS */
202 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
205 SV * const sv = sv_newmortal();
206 if (!(flags & HVhek_FREEKEY)) {
207 sv_setpvn(sv, key, klen);
210 /* Need to free saved eventually assign to mortal SV */
211 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
212 sv_usepvn(sv, (char *) key, klen);
214 if (flags & HVhek_UTF8) {
217 Perl_croak(aTHX_ msg, sv);
220 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
223 #define HV_FETCH_ISSTORE 0x01
224 #define HV_FETCH_ISEXISTS 0x02
225 #define HV_FETCH_LVALUE 0x04
226 #define HV_FETCH_JUST_SV 0x08
231 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
232 the length of the key. The C<hash> parameter is the precomputed hash
233 value; if it is zero then Perl will compute it. The return value will be
234 NULL if the operation failed or if the value did not need to be actually
235 stored within the hash (as in the case of tied hashes). Otherwise it can
236 be dereferenced to get the original C<SV*>. Note that the caller is
237 responsible for suitably incrementing the reference count of C<val> before
238 the call, and decrementing it if the function returned NULL. Effectively
239 a successful hv_store takes ownership of one reference to C<val>. This is
240 usually what you want; a newly created SV has a reference count of one, so
241 if all your code does is create SVs then store them in a hash, hv_store
242 will own the only reference to the new SV, and your code doesn't need to do
243 anything further to tidy up. hv_store is not implemented as a call to
244 hv_store_ent, and does not create a temporary SV for the key, so if your
245 key data is not already in SV form then use hv_store in preference to
248 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
249 information on how to use this function on tied hashes.
255 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
268 hek = hv_fetch_common (hv, NULL, key, klen, flags,
269 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
270 return hek ? &HeVAL(hek) : NULL;
273 /* XXX This looks like an ideal candidate to inline */
275 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
276 register U32 hash, int flags)
278 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
279 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
280 return hek ? &HeVAL(hek) : NULL;
284 =for apidoc hv_store_ent
286 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
287 parameter is the precomputed hash value; if it is zero then Perl will
288 compute it. The return value is the new hash entry so created. It will be
289 NULL if the operation failed or if the value did not need to be actually
290 stored within the hash (as in the case of tied hashes). Otherwise the
291 contents of the return value can be accessed using the C<He?> macros
292 described here. Note that the caller is responsible for suitably
293 incrementing the reference count of C<val> before the call, and
294 decrementing it if the function returned NULL. Effectively a successful
295 hv_store_ent takes ownership of one reference to C<val>. This is
296 usually what you want; a newly created SV has a reference count of one, so
297 if all your code does is create SVs then store them in a hash, hv_store
298 will own the only reference to the new SV, and your code doesn't need to do
299 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
300 unlike C<val> it does not take ownership of it, so maintaining the correct
301 reference count on C<key> is entirely the caller's responsibility. hv_store
302 is not implemented as a call to hv_store_ent, and does not create a temporary
303 SV for the key, so if your key data is not already in SV form then use
304 hv_store in preference to hv_store_ent.
306 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
307 information on how to use this function on tied hashes.
312 /* XXX This looks like an ideal candidate to inline */
314 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
316 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
320 =for apidoc hv_exists
322 Returns a boolean indicating whether the specified hash key exists. The
323 C<klen> is the length of the key.
329 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
341 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
348 Returns the SV which corresponds to the specified key in the hash. The
349 C<klen> is the length of the key. If C<lval> is set then the fetch will be
350 part of a store. Check that the return value is non-null before
351 dereferencing it to an C<SV*>.
353 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
354 information on how to use this function on tied hashes.
360 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
373 hek = hv_fetch_common (hv, NULL, key, klen, flags,
374 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
376 return hek ? &HeVAL(hek) : NULL;
380 =for apidoc hv_exists_ent
382 Returns a boolean indicating whether the specified hash key exists. C<hash>
383 can be a valid precomputed hash value, or 0 to ask for it to be
389 /* XXX This looks like an ideal candidate to inline */
391 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
393 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
397 /* returns an HE * structure with the all fields set */
398 /* note that hent_val will be a mortal sv for MAGICAL hashes */
400 =for apidoc hv_fetch_ent
402 Returns the hash entry which corresponds to the specified key in the hash.
403 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
404 if you want the function to compute it. IF C<lval> is set then the fetch
405 will be part of a store. Make sure the return value is non-null before
406 accessing it. The return value when C<tb> is a tied hash is a pointer to a
407 static location, so be sure to make a copy of the structure if you need to
410 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
411 information on how to use this function on tied hashes.
417 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
419 return hv_fetch_common(hv, keysv, NULL, 0, 0,
420 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
424 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
425 int flags, int action, SV *val, register U32 hash)
439 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
440 keysv = hv_magic_uvar_xkey(hv, keysv, action);
441 if (flags & HVhek_FREEKEY)
443 key = SvPV_const(keysv, klen);
445 is_utf8 = (SvUTF8(keysv) != 0);
447 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
450 xhv = (XPVHV*)SvANY(hv);
452 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
453 MAGIC *regdata = NULL;
454 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)
455 || (regdata = mg_find((SV*)hv, PERL_MAGIC_regdata_names))) {
457 /* XXX should be able to skimp on the HE/HEK here when
458 HV_FETCH_JUST_SV is true. */
460 keysv = newSVpvn(key, klen);
465 keysv = newSVsv(keysv);
468 sv = Perl_reg_named_buff_sv(aTHX_ keysv);
475 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
478 /* grab a fake HE/HEK pair from the pool or make a new one */
479 entry = PL_hv_fetch_ent_mh;
481 PL_hv_fetch_ent_mh = HeNEXT(entry);
485 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
486 HeKEY_hek(entry) = (HEK*)k;
488 HeNEXT(entry) = NULL;
489 HeSVKEY_set(entry, keysv);
491 sv_upgrade(sv, SVt_PVLV);
493 /* so we can free entry when freeing sv */
494 LvTARG(sv) = (SV*)entry;
496 /* XXX remove at some point? */
497 if (flags & HVhek_FREEKEY)
502 #ifdef ENV_IS_CASELESS
503 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
505 for (i = 0; i < klen; ++i)
506 if (isLOWER(key[i])) {
507 /* Would be nice if we had a routine to do the
508 copy and upercase in a single pass through. */
509 const char * const nkey = strupr(savepvn(key,klen));
510 /* Note that this fetch is for nkey (the uppercased
511 key) whereas the store is for key (the original) */
512 entry = hv_fetch_common(hv, NULL, nkey, klen,
513 HVhek_FREEKEY, /* free nkey */
514 0 /* non-LVAL fetch */,
516 0 /* compute hash */);
517 if (!entry && (action & HV_FETCH_LVALUE)) {
518 /* This call will free key if necessary.
519 Do it this way to encourage compiler to tail
521 entry = hv_fetch_common(hv, keysv, key, klen,
522 flags, HV_FETCH_ISSTORE,
525 if (flags & HVhek_FREEKEY)
533 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
534 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
535 /* I don't understand why hv_exists_ent has svret and sv,
536 whereas hv_exists only had one. */
537 SV * const svret = sv_newmortal();
540 if (keysv || is_utf8) {
542 keysv = newSVpvn(key, klen);
545 keysv = newSVsv(keysv);
547 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
549 mg_copy((SV*)hv, sv, key, klen);
551 if (flags & HVhek_FREEKEY)
553 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
554 /* This cast somewhat evil, but I'm merely using NULL/
555 not NULL to return the boolean exists.
556 And I know hv is not NULL. */
557 return SvTRUE(svret) ? (HE *)hv : NULL;
559 #ifdef ENV_IS_CASELESS
560 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
561 /* XXX This code isn't UTF8 clean. */
562 char * const keysave = (char * const)key;
563 /* Will need to free this, so set FREEKEY flag. */
564 key = savepvn(key,klen);
565 key = (const char*)strupr((char*)key);
570 if (flags & HVhek_FREEKEY) {
573 flags |= HVhek_FREEKEY;
577 else if (action & HV_FETCH_ISSTORE) {
580 hv_magic_check (hv, &needs_copy, &needs_store);
582 const bool save_taint = PL_tainted;
583 if (keysv || is_utf8) {
585 keysv = newSVpvn(key, klen);
589 PL_tainted = SvTAINTED(keysv);
590 keysv = sv_2mortal(newSVsv(keysv));
591 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
593 mg_copy((SV*)hv, val, key, klen);
596 TAINT_IF(save_taint);
598 if (flags & HVhek_FREEKEY)
602 #ifdef ENV_IS_CASELESS
603 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
604 /* XXX This code isn't UTF8 clean. */
605 const char *keysave = key;
606 /* Will need to free this, so set FREEKEY flag. */
607 key = savepvn(key,klen);
608 key = (const char*)strupr((char*)key);
613 if (flags & HVhek_FREEKEY) {
616 flags |= HVhek_FREEKEY;
624 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
625 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
626 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
631 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
633 HvARRAY(hv) = (HE**)array;
635 #ifdef DYNAMIC_ENV_FETCH
636 else if (action & HV_FETCH_ISEXISTS) {
637 /* for an %ENV exists, if we do an insert it's by a recursive
638 store call, so avoid creating HvARRAY(hv) right now. */
642 /* XXX remove at some point? */
643 if (flags & HVhek_FREEKEY)
651 char * const keysave = (char *)key;
652 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
656 flags &= ~HVhek_UTF8;
657 if (key != keysave) {
658 if (flags & HVhek_FREEKEY)
660 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
665 PERL_HASH_INTERNAL(hash, key, klen);
666 /* We don't have a pointer to the hv, so we have to replicate the
667 flag into every HEK, so that hv_iterkeysv can see it. */
668 /* And yes, you do need this even though you are not "storing" because
669 you can flip the flags below if doing an lval lookup. (And that
670 was put in to give the semantics Andreas was expecting.) */
671 flags |= HVhek_REHASH;
673 if (keysv && (SvIsCOW_shared_hash(keysv))) {
674 hash = SvSHARED_HASH(keysv);
676 PERL_HASH(hash, key, klen);
680 masked_flags = (flags & HVhek_MASK);
682 #ifdef DYNAMIC_ENV_FETCH
683 if (!HvARRAY(hv)) entry = NULL;
687 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
689 for (; entry; entry = HeNEXT(entry)) {
690 if (HeHASH(entry) != hash) /* strings can't be equal */
692 if (HeKLEN(entry) != (I32)klen)
694 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
696 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
699 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
700 if (HeKFLAGS(entry) != masked_flags) {
701 /* We match if HVhek_UTF8 bit in our flags and hash key's
702 match. But if entry was set previously with HVhek_WASUTF8
703 and key now doesn't (or vice versa) then we should change
704 the key's flag, as this is assignment. */
705 if (HvSHAREKEYS(hv)) {
706 /* Need to swap the key we have for a key with the flags we
707 need. As keys are shared we can't just write to the
708 flag, so we share the new one, unshare the old one. */
709 HEK * const new_hek = share_hek_flags(key, klen, hash,
711 unshare_hek (HeKEY_hek(entry));
712 HeKEY_hek(entry) = new_hek;
714 else if (hv == PL_strtab) {
715 /* PL_strtab is usually the only hash without HvSHAREKEYS,
716 so putting this test here is cheap */
717 if (flags & HVhek_FREEKEY)
719 Perl_croak(aTHX_ S_strtab_error,
720 action & HV_FETCH_LVALUE ? "fetch" : "store");
723 HeKFLAGS(entry) = masked_flags;
724 if (masked_flags & HVhek_ENABLEHVKFLAGS)
727 if (HeVAL(entry) == &PL_sv_placeholder) {
728 /* yes, can store into placeholder slot */
729 if (action & HV_FETCH_LVALUE) {
731 /* This preserves behaviour with the old hv_fetch
732 implementation which at this point would bail out
733 with a break; (at "if we find a placeholder, we
734 pretend we haven't found anything")
736 That break mean that if a placeholder were found, it
737 caused a call into hv_store, which in turn would
738 check magic, and if there is no magic end up pretty
739 much back at this point (in hv_store's code). */
742 /* LVAL fetch which actaully needs a store. */
744 HvPLACEHOLDERS(hv)--;
747 if (val != &PL_sv_placeholder)
748 HvPLACEHOLDERS(hv)--;
751 } else if (action & HV_FETCH_ISSTORE) {
752 SvREFCNT_dec(HeVAL(entry));
755 } else if (HeVAL(entry) == &PL_sv_placeholder) {
756 /* if we find a placeholder, we pretend we haven't found
760 if (flags & HVhek_FREEKEY)
764 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
765 if (!(action & HV_FETCH_ISSTORE)
766 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
768 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
770 sv = newSVpvn(env,len);
772 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
778 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
779 hv_notallowed(flags, key, klen,
780 "Attempt to access disallowed key '%"SVf"' in"
781 " a restricted hash");
783 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
784 /* Not doing some form of store, so return failure. */
785 if (flags & HVhek_FREEKEY)
789 if (action & HV_FETCH_LVALUE) {
792 /* At this point the old hv_fetch code would call to hv_store,
793 which in turn might do some tied magic. So we need to make that
794 magic check happen. */
795 /* gonna assign to this, so it better be there */
796 return hv_fetch_common(hv, keysv, key, klen, flags,
797 HV_FETCH_ISSTORE, val, hash);
798 /* XXX Surely that could leak if the fetch-was-store fails?
799 Just like the hv_fetch. */
803 /* Welcome to hv_store... */
806 /* Not sure if we can get here. I think the only case of oentry being
807 NULL is for %ENV with dynamic env fetch. But that should disappear
808 with magic in the previous code. */
811 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
813 HvARRAY(hv) = (HE**)array;
816 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
819 /* share_hek_flags will do the free for us. This might be considered
822 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
823 else if (hv == PL_strtab) {
824 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
825 this test here is cheap */
826 if (flags & HVhek_FREEKEY)
828 Perl_croak(aTHX_ S_strtab_error,
829 action & HV_FETCH_LVALUE ? "fetch" : "store");
831 else /* gotta do the real thing */
832 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
834 HeNEXT(entry) = *oentry;
837 if (val == &PL_sv_placeholder)
838 HvPLACEHOLDERS(hv)++;
839 if (masked_flags & HVhek_ENABLEHVKFLAGS)
843 const HE *counter = HeNEXT(entry);
845 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
846 if (!counter) { /* initial entry? */
847 xhv->xhv_fill++; /* HvFILL(hv)++ */
848 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
850 } else if(!HvREHASH(hv)) {
853 while ((counter = HeNEXT(counter)))
856 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
857 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
858 bucket splits on a rehashed hash, as we're not going to
859 split it again, and if someone is lucky (evil) enough to
860 get all the keys in one list they could exhaust our memory
861 as we repeatedly double the number of buckets on every
862 entry. Linear search feels a less worse thing to do. */
872 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
874 const MAGIC *mg = SvMAGIC(hv);
878 if (isUPPER(mg->mg_type)) {
880 if (mg->mg_type == PERL_MAGIC_tied) {
881 *needs_store = FALSE;
882 return; /* We've set all there is to set. */
885 mg = mg->mg_moremagic;
890 =for apidoc hv_scalar
892 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
898 Perl_hv_scalar(pTHX_ HV *hv)
902 if (SvRMAGICAL(hv)) {
903 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
905 return magic_scalarpack(hv, mg);
910 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
911 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
919 =for apidoc hv_delete
921 Deletes a key/value pair in the hash. The value SV is removed from the
922 hash and returned to the caller. The C<klen> is the length of the key.
923 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
930 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
937 k_flags = HVhek_UTF8;
942 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
946 =for apidoc hv_delete_ent
948 Deletes a key/value pair in the hash. The value SV is removed from the
949 hash and returned to the caller. The C<flags> value will normally be zero;
950 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
951 precomputed hash value, or 0 to ask for it to be computed.
956 /* XXX This looks like an ideal candidate to inline */
958 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
960 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
964 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
965 int k_flags, I32 d_flags, U32 hash)
970 register HE **oentry;
971 HE *const *first_entry;
979 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
980 keysv = hv_magic_uvar_xkey(hv, keysv, -1);
981 if (k_flags & HVhek_FREEKEY)
983 key = SvPV_const(keysv, klen);
985 is_utf8 = (SvUTF8(keysv) != 0);
987 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
990 if (SvRMAGICAL(hv)) {
993 hv_magic_check (hv, &needs_copy, &needs_store);
997 entry = hv_fetch_common(hv, keysv, key, klen,
998 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
1000 sv = entry ? HeVAL(entry) : NULL;
1002 if (SvMAGICAL(sv)) {
1006 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1007 /* No longer an element */
1008 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1011 return NULL; /* element cannot be deleted */
1013 #ifdef ENV_IS_CASELESS
1014 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1015 /* XXX This code isn't UTF8 clean. */
1016 keysv = sv_2mortal(newSVpvn(key,klen));
1017 if (k_flags & HVhek_FREEKEY) {
1020 key = strupr(SvPVX(keysv));
1029 xhv = (XPVHV*)SvANY(hv);
1034 const char * const keysave = key;
1035 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1038 k_flags |= HVhek_UTF8;
1040 k_flags &= ~HVhek_UTF8;
1041 if (key != keysave) {
1042 if (k_flags & HVhek_FREEKEY) {
1043 /* This shouldn't happen if our caller does what we expect,
1044 but strictly the API allows it. */
1047 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1049 HvHASKFLAGS_on((SV*)hv);
1053 PERL_HASH_INTERNAL(hash, key, klen);
1055 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1056 hash = SvSHARED_HASH(keysv);
1058 PERL_HASH(hash, key, klen);
1062 masked_flags = (k_flags & HVhek_MASK);
1064 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1066 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1068 if (HeHASH(entry) != hash) /* strings can't be equal */
1070 if (HeKLEN(entry) != (I32)klen)
1072 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1074 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1077 if (hv == PL_strtab) {
1078 if (k_flags & HVhek_FREEKEY)
1080 Perl_croak(aTHX_ S_strtab_error, "delete");
1083 /* if placeholder is here, it's already been deleted.... */
1084 if (HeVAL(entry) == &PL_sv_placeholder) {
1085 if (k_flags & HVhek_FREEKEY)
1089 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1090 hv_notallowed(k_flags, key, klen,
1091 "Attempt to delete readonly key '%"SVf"' from"
1092 " a restricted hash");
1094 if (k_flags & HVhek_FREEKEY)
1097 if (d_flags & G_DISCARD)
1100 sv = sv_2mortal(HeVAL(entry));
1101 HeVAL(entry) = &PL_sv_placeholder;
1105 * If a restricted hash, rather than really deleting the entry, put
1106 * a placeholder there. This marks the key as being "approved", so
1107 * we can still access via not-really-existing key without raising
1110 if (SvREADONLY(hv)) {
1111 SvREFCNT_dec(HeVAL(entry));
1112 HeVAL(entry) = &PL_sv_placeholder;
1113 /* We'll be saving this slot, so the number of allocated keys
1114 * doesn't go down, but the number placeholders goes up */
1115 HvPLACEHOLDERS(hv)++;
1117 *oentry = HeNEXT(entry);
1119 xhv->xhv_fill--; /* HvFILL(hv)-- */
1121 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1124 hv_free_ent(hv, entry);
1125 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1126 if (xhv->xhv_keys == 0)
1127 HvHASKFLAGS_off(hv);
1131 if (SvREADONLY(hv)) {
1132 hv_notallowed(k_flags, key, klen,
1133 "Attempt to delete disallowed key '%"SVf"' from"
1134 " a restricted hash");
1137 if (k_flags & HVhek_FREEKEY)
1143 S_hsplit(pTHX_ HV *hv)
1146 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1147 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1148 register I32 newsize = oldsize * 2;
1150 char *a = (char*) HvARRAY(hv);
1152 register HE **oentry;
1153 int longest_chain = 0;
1156 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1157 hv, (int) oldsize);*/
1159 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1160 /* Can make this clear any placeholders first for non-restricted hashes,
1161 even though Storable rebuilds restricted hashes by putting in all the
1162 placeholders (first) before turning on the readonly flag, because
1163 Storable always pre-splits the hash. */
1164 hv_clear_placeholders(hv);
1168 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1169 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1170 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1176 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1179 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1180 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1185 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1187 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1189 if (oldsize >= 64) {
1190 offer_nice_chunk(HvARRAY(hv),
1191 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1192 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1195 Safefree(HvARRAY(hv));
1199 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1200 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1201 HvARRAY(hv) = (HE**) a;
1204 for (i=0; i<oldsize; i++,aep++) {
1205 int left_length = 0;
1206 int right_length = 0;
1210 if (!*aep) /* non-existent */
1213 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1214 if ((HeHASH(entry) & newsize) != (U32)i) {
1215 *oentry = HeNEXT(entry);
1216 HeNEXT(entry) = *bep;
1218 xhv->xhv_fill++; /* HvFILL(hv)++ */
1224 oentry = &HeNEXT(entry);
1228 if (!*aep) /* everything moved */
1229 xhv->xhv_fill--; /* HvFILL(hv)-- */
1230 /* I think we don't actually need to keep track of the longest length,
1231 merely flag if anything is too long. But for the moment while
1232 developing this code I'll track it. */
1233 if (left_length > longest_chain)
1234 longest_chain = left_length;
1235 if (right_length > longest_chain)
1236 longest_chain = right_length;
1240 /* Pick your policy for "hashing isn't working" here: */
1241 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1246 if (hv == PL_strtab) {
1247 /* Urg. Someone is doing something nasty to the string table.
1252 /* Awooga. Awooga. Pathological data. */
1253 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1254 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1257 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1258 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1260 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1263 was_shared = HvSHAREKEYS(hv);
1266 HvSHAREKEYS_off(hv);
1271 for (i=0; i<newsize; i++,aep++) {
1272 register HE *entry = *aep;
1274 /* We're going to trash this HE's next pointer when we chain it
1275 into the new hash below, so store where we go next. */
1276 HE * const next = HeNEXT(entry);
1281 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1286 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1287 hash, HeKFLAGS(entry));
1288 unshare_hek (HeKEY_hek(entry));
1289 HeKEY_hek(entry) = new_hek;
1291 /* Not shared, so simply write the new hash in. */
1292 HeHASH(entry) = hash;
1294 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1295 HEK_REHASH_on(HeKEY_hek(entry));
1296 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1298 /* Copy oentry to the correct new chain. */
1299 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1301 xhv->xhv_fill++; /* HvFILL(hv)++ */
1302 HeNEXT(entry) = *bep;
1308 Safefree (HvARRAY(hv));
1309 HvARRAY(hv) = (HE **)a;
1313 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1316 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1317 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1318 register I32 newsize;
1323 register HE **oentry;
1325 newsize = (I32) newmax; /* possible truncation here */
1326 if (newsize != newmax || newmax <= oldsize)
1328 while ((newsize & (1 + ~newsize)) != newsize) {
1329 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1331 if (newsize < newmax)
1333 if (newsize < newmax)
1334 return; /* overflow detection */
1336 a = (char *) HvARRAY(hv);
1339 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1340 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1341 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1347 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1350 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1351 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1356 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1358 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1360 if (oldsize >= 64) {
1361 offer_nice_chunk(HvARRAY(hv),
1362 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1363 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1366 Safefree(HvARRAY(hv));
1369 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1372 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1374 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1375 HvARRAY(hv) = (HE **) a;
1376 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1380 for (i=0; i<oldsize; i++,aep++) {
1381 if (!*aep) /* non-existent */
1383 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1384 register I32 j = (HeHASH(entry) & newsize);
1388 *oentry = HeNEXT(entry);
1389 if (!(HeNEXT(entry) = aep[j]))
1390 xhv->xhv_fill++; /* HvFILL(hv)++ */
1395 oentry = &HeNEXT(entry);
1397 if (!*aep) /* everything moved */
1398 xhv->xhv_fill--; /* HvFILL(hv)-- */
1405 Creates a new HV. The reference count is set to 1.
1413 register XPVHV* xhv;
1414 HV * const hv = (HV*)newSV(0);
1416 sv_upgrade((SV *)hv, SVt_PVHV);
1417 xhv = (XPVHV*)SvANY(hv);
1420 #ifndef NODEFAULT_SHAREKEYS
1421 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1424 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1425 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1430 Perl_newHVhv(pTHX_ HV *ohv)
1432 HV * const hv = newHV();
1433 STRLEN hv_max, hv_fill;
1435 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1437 hv_max = HvMAX(ohv);
1439 if (!SvMAGICAL((SV *)ohv)) {
1440 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1442 const bool shared = !!HvSHAREKEYS(ohv);
1443 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1445 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1448 /* In each bucket... */
1449 for (i = 0; i <= hv_max; i++) {
1451 HE *oent = oents[i];
1458 /* Copy the linked list of entries. */
1459 for (; oent; oent = HeNEXT(oent)) {
1460 const U32 hash = HeHASH(oent);
1461 const char * const key = HeKEY(oent);
1462 const STRLEN len = HeKLEN(oent);
1463 const int flags = HeKFLAGS(oent);
1464 HE * const ent = new_HE();
1466 HeVAL(ent) = newSVsv(HeVAL(oent));
1468 = shared ? share_hek_flags(key, len, hash, flags)
1469 : save_hek_flags(key, len, hash, flags);
1480 HvFILL(hv) = hv_fill;
1481 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1485 /* Iterate over ohv, copying keys and values one at a time. */
1487 const I32 riter = HvRITER_get(ohv);
1488 HE * const eiter = HvEITER_get(ohv);
1490 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1491 while (hv_max && hv_max + 1 >= hv_fill * 2)
1492 hv_max = hv_max / 2;
1496 while ((entry = hv_iternext_flags(ohv, 0))) {
1497 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1498 newSVsv(HeVAL(entry)), HeHASH(entry),
1501 HvRITER_set(ohv, riter);
1502 HvEITER_set(ohv, eiter);
1508 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1509 magic stays on it. */
1511 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1513 HV * const hv = newHV();
1516 if (ohv && (hv_fill = HvFILL(ohv))) {
1517 STRLEN hv_max = HvMAX(ohv);
1519 const I32 riter = HvRITER_get(ohv);
1520 HE * const eiter = HvEITER_get(ohv);
1522 while (hv_max && hv_max + 1 >= hv_fill * 2)
1523 hv_max = hv_max / 2;
1527 while ((entry = hv_iternext_flags(ohv, 0))) {
1528 SV *const sv = newSVsv(HeVAL(entry));
1529 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1530 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1531 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1532 sv, HeHASH(entry), HeKFLAGS(entry));
1534 HvRITER_set(ohv, riter);
1535 HvEITER_set(ohv, eiter);
1537 hv_magic(hv, NULL, PERL_MAGIC_hints);
1542 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1550 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1551 PL_sub_generation++; /* may be deletion of method from stash */
1553 if (HeKLEN(entry) == HEf_SVKEY) {
1554 SvREFCNT_dec(HeKEY_sv(entry));
1555 Safefree(HeKEY_hek(entry));
1557 else if (HvSHAREKEYS(hv))
1558 unshare_hek(HeKEY_hek(entry));
1560 Safefree(HeKEY_hek(entry));
1565 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1570 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1571 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1572 if (HeKLEN(entry) == HEf_SVKEY) {
1573 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1575 hv_free_ent(hv, entry);
1579 =for apidoc hv_clear
1581 Clears a hash, making it empty.
1587 Perl_hv_clear(pTHX_ HV *hv)
1590 register XPVHV* xhv;
1594 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1596 xhv = (XPVHV*)SvANY(hv);
1598 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1599 /* restricted hash: convert all keys to placeholders */
1601 for (i = 0; i <= xhv->xhv_max; i++) {
1602 HE *entry = (HvARRAY(hv))[i];
1603 for (; entry; entry = HeNEXT(entry)) {
1604 /* not already placeholder */
1605 if (HeVAL(entry) != &PL_sv_placeholder) {
1606 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1607 SV* const keysv = hv_iterkeysv(entry);
1609 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1612 SvREFCNT_dec(HeVAL(entry));
1613 HeVAL(entry) = &PL_sv_placeholder;
1614 HvPLACEHOLDERS(hv)++;
1622 HvPLACEHOLDERS_set(hv, 0);
1624 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1629 HvHASKFLAGS_off(hv);
1633 HvEITER_set(hv, NULL);
1638 =for apidoc hv_clear_placeholders
1640 Clears any placeholders from a hash. If a restricted hash has any of its keys
1641 marked as readonly and the key is subsequently deleted, the key is not actually
1642 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1643 it so it will be ignored by future operations such as iterating over the hash,
1644 but will still allow the hash to have a value reassigned to the key at some
1645 future point. This function clears any such placeholder keys from the hash.
1646 See Hash::Util::lock_keys() for an example of its use.
1652 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1655 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1658 clear_placeholders(hv, items);
1662 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1672 /* Loop down the linked list heads */
1674 HE **oentry = &(HvARRAY(hv))[i];
1677 while ((entry = *oentry)) {
1678 if (HeVAL(entry) == &PL_sv_placeholder) {
1679 *oentry = HeNEXT(entry);
1680 if (first && !*oentry)
1681 HvFILL(hv)--; /* This linked list is now empty. */
1682 if (entry == HvEITER_get(hv))
1685 hv_free_ent(hv, entry);
1689 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1690 if (HvKEYS(hv) == 0)
1691 HvHASKFLAGS_off(hv);
1692 HvPLACEHOLDERS_set(hv, 0);
1696 oentry = &HeNEXT(entry);
1701 /* You can't get here, hence assertion should always fail. */
1702 assert (items == 0);
1707 S_hfreeentries(pTHX_ HV *hv)
1709 /* This is the array that we're going to restore */
1718 /* If the hash is actually a symbol table with a name, look after the
1720 struct xpvhv_aux *iter = HvAUX(hv);
1722 name = iter->xhv_name;
1723 iter->xhv_name = NULL;
1728 orig_array = HvARRAY(hv);
1729 /* orig_array remains unchanged throughout the loop. If after freeing all
1730 the entries it turns out that one of the little blighters has triggered
1731 an action that has caused HvARRAY to be re-allocated, then we set
1732 array to the new HvARRAY, and try again. */
1735 /* This is the one we're going to try to empty. First time round
1736 it's the original array. (Hopefully there will only be 1 time
1738 HE ** const array = HvARRAY(hv);
1741 /* Because we have taken xhv_name out, the only allocated pointer
1742 in the aux structure that might exist is the backreference array.
1747 struct xpvhv_aux *iter = HvAUX(hv);
1748 /* If there are weak references to this HV, we need to avoid
1749 freeing them up here. In particular we need to keep the AV
1750 visible as what we're deleting might well have weak references
1751 back to this HV, so the for loop below may well trigger
1752 the removal of backreferences from this array. */
1754 if (iter->xhv_backreferences) {
1755 /* So donate them to regular backref magic to keep them safe.
1756 The sv_magic will increase the reference count of the AV,
1757 so we need to drop it first. */
1758 SvREFCNT_dec(iter->xhv_backreferences);
1759 if (AvFILLp(iter->xhv_backreferences) == -1) {
1760 /* Turns out that the array is empty. Just free it. */
1761 SvREFCNT_dec(iter->xhv_backreferences);
1764 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1765 PERL_MAGIC_backref, NULL, 0);
1767 iter->xhv_backreferences = NULL;
1770 entry = iter->xhv_eiter; /* HvEITER(hv) */
1771 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1773 hv_free_ent(hv, entry);
1775 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1776 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1778 /* There are now no allocated pointers in the aux structure. */
1780 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1781 /* What aux structure? */
1784 /* make everyone else think the array is empty, so that the destructors
1785 * called for freed entries can't recusively mess with us */
1788 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1792 /* Loop down the linked list heads */
1793 HE *entry = array[i];
1796 register HE * const oentry = entry;
1797 entry = HeNEXT(entry);
1798 hv_free_ent(hv, oentry);
1802 /* As there are no allocated pointers in the aux structure, it's now
1803 safe to free the array we just cleaned up, if it's not the one we're
1804 going to put back. */
1805 if (array != orig_array) {
1810 /* Good. No-one added anything this time round. */
1815 /* Someone attempted to iterate or set the hash name while we had
1816 the array set to 0. We'll catch backferences on the next time
1817 round the while loop. */
1818 assert(HvARRAY(hv));
1820 if (HvAUX(hv)->xhv_name) {
1821 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1825 if (--attempts == 0) {
1826 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1830 HvARRAY(hv) = orig_array;
1832 /* If the hash was actually a symbol table, put the name back. */
1834 /* We have restored the original array. If name is non-NULL, then
1835 the original array had an aux structure at the end. So this is
1837 SvFLAGS(hv) |= SVf_OOK;
1838 HvAUX(hv)->xhv_name = name;
1843 =for apidoc hv_undef
1851 Perl_hv_undef(pTHX_ HV *hv)
1854 register XPVHV* xhv;
1859 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1860 xhv = (XPVHV*)SvANY(hv);
1862 if ((name = HvNAME_get(hv))) {
1864 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1865 hv_name_set(hv, NULL, 0, 0);
1867 SvFLAGS(hv) &= ~SVf_OOK;
1868 Safefree(HvARRAY(hv));
1869 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1871 HvPLACEHOLDERS_set(hv, 0);
1877 static struct xpvhv_aux*
1878 S_hv_auxinit(HV *hv) {
1879 struct xpvhv_aux *iter;
1883 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1884 + sizeof(struct xpvhv_aux), char);
1886 array = (char *) HvARRAY(hv);
1887 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1888 + sizeof(struct xpvhv_aux), char);
1890 HvARRAY(hv) = (HE**) array;
1891 /* SvOOK_on(hv) attacks the IV flags. */
1892 SvFLAGS(hv) |= SVf_OOK;
1895 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1896 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1898 iter->xhv_backreferences = 0;
1903 =for apidoc hv_iterinit
1905 Prepares a starting point to traverse a hash table. Returns the number of
1906 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1907 currently only meaningful for hashes without tie magic.
1909 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1910 hash buckets that happen to be in use. If you still need that esoteric
1911 value, you can get it through the macro C<HvFILL(tb)>.
1918 Perl_hv_iterinit(pTHX_ HV *hv)
1921 Perl_croak(aTHX_ "Bad hash");
1924 struct xpvhv_aux * const iter = HvAUX(hv);
1925 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1926 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1928 hv_free_ent(hv, entry);
1930 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1931 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1935 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
1936 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_regdata_names);
1939 const REGEXP * const rx = PM_GETRE(PL_curpm);
1940 if (rx && rx->paren_names) {
1941 (void)hv_iterinit(rx->paren_names);
1946 /* used to be xhv->xhv_fill before 5.004_65 */
1947 return HvTOTALKEYS(hv);
1951 Perl_hv_riter_p(pTHX_ HV *hv) {
1952 struct xpvhv_aux *iter;
1955 Perl_croak(aTHX_ "Bad hash");
1957 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1958 return &(iter->xhv_riter);
1962 Perl_hv_eiter_p(pTHX_ HV *hv) {
1963 struct xpvhv_aux *iter;
1966 Perl_croak(aTHX_ "Bad hash");
1968 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1969 return &(iter->xhv_eiter);
1973 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1974 struct xpvhv_aux *iter;
1977 Perl_croak(aTHX_ "Bad hash");
1985 iter = hv_auxinit(hv);
1987 iter->xhv_riter = riter;
1991 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1992 struct xpvhv_aux *iter;
1995 Perl_croak(aTHX_ "Bad hash");
2000 /* 0 is the default so don't go malloc()ing a new structure just to
2005 iter = hv_auxinit(hv);
2007 iter->xhv_eiter = eiter;
2011 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2014 struct xpvhv_aux *iter;
2017 PERL_UNUSED_ARG(flags);
2020 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2024 if (iter->xhv_name) {
2025 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2031 iter = hv_auxinit(hv);
2033 PERL_HASH(hash, name, len);
2034 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2038 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2039 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2040 PERL_UNUSED_CONTEXT;
2041 return &(iter->xhv_backreferences);
2045 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2051 av = HvAUX(hv)->xhv_backreferences;
2054 HvAUX(hv)->xhv_backreferences = 0;
2055 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2060 hv_iternext is implemented as a macro in hv.h
2062 =for apidoc hv_iternext
2064 Returns entries from a hash iterator. See C<hv_iterinit>.
2066 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2067 iterator currently points to, without losing your place or invalidating your
2068 iterator. Note that in this case the current entry is deleted from the hash
2069 with your iterator holding the last reference to it. Your iterator is flagged
2070 to free the entry on the next call to C<hv_iternext>, so you must not discard
2071 your iterator immediately else the entry will leak - call C<hv_iternext> to
2072 trigger the resource deallocation.
2074 =for apidoc hv_iternext_flags
2076 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2077 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2078 set the placeholders keys (for restricted hashes) will be returned in addition
2079 to normal keys. By default placeholders are automatically skipped over.
2080 Currently a placeholder is implemented with a value that is
2081 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2082 restricted hashes may change, and the implementation currently is
2083 insufficiently abstracted for any change to be tidy.
2089 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2092 register XPVHV* xhv;
2096 struct xpvhv_aux *iter;
2099 Perl_croak(aTHX_ "Bad hash");
2101 xhv = (XPVHV*)SvANY(hv);
2104 /* Too many things (well, pp_each at least) merrily assume that you can
2105 call iv_iternext without calling hv_iterinit, so we'll have to deal
2111 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2112 if (SvMAGICAL(hv) && SvRMAGICAL(hv) &&
2113 (mg = mg_find((SV*)hv, PERL_MAGIC_regdata_names)))
2120 rx = PM_GETRE(PL_curpm);
2121 if (rx && rx->paren_names) {
2122 hv = rx->paren_names;
2127 key = sv_newmortal();
2129 sv_setsv(key, HeSVKEY_force(entry));
2130 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2136 /* one HE per MAGICAL hash */
2137 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2139 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2141 HeKEY_hek(entry) = hek;
2142 HeKLEN(entry) = HEf_SVKEY;
2146 HE *temphe = hv_iternext_flags(hv,flags);
2150 SV* sv_dat = HeVAL(temphe);
2151 I32 *nums = (I32*)SvPVX(sv_dat);
2152 for ( i = 0; i < SvIVX(sv_dat); i++ ) {
2153 if ((I32)(rx->lastcloseparen) >= nums[i] &&
2154 rx->startp[nums[i]] != -1 &&
2155 rx->endp[nums[i]] != -1)
2164 SV *sv = sv_newmortal();
2165 const char* pvkey = HePV(temphe, len);
2167 Perl_sv_setpvf(aTHX_ sv, "%"IVdf,(IV)parno);
2168 gv_paren = Perl_gv_fetchsv(aTHX_ sv, GV_ADD, SVt_PVGV);
2169 Perl_sv_setpvn(aTHX_ key, pvkey, len);
2170 val = GvSVn(gv_paren);
2177 if (val && SvOK(key)) {
2178 /* force key to stay around until next time */
2179 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2180 HeVAL(entry) = SvREFCNT_inc_simple_NN(val);
2181 return entry; /* beware, hent_val is not set */
2184 SvREFCNT_dec(HeVAL(entry));
2185 Safefree(HeKEY_hek(entry));
2187 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2190 } else if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
2191 SV * const key = sv_newmortal();
2193 sv_setsv(key, HeSVKEY_force(entry));
2194 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2200 /* one HE per MAGICAL hash */
2201 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2203 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2205 HeKEY_hek(entry) = hek;
2206 HeKLEN(entry) = HEf_SVKEY;
2208 magic_nextpack((SV*) hv,mg,key);
2210 /* force key to stay around until next time */
2211 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2212 return entry; /* beware, hent_val is not set */
2215 SvREFCNT_dec(HeVAL(entry));
2216 Safefree(HeKEY_hek(entry));
2218 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2221 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2222 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2225 /* The prime_env_iter() on VMS just loaded up new hash values
2226 * so the iteration count needs to be reset back to the beginning
2230 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2235 /* hv_iterint now ensures this. */
2236 assert (HvARRAY(hv));
2238 /* At start of hash, entry is NULL. */
2241 entry = HeNEXT(entry);
2242 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2244 * Skip past any placeholders -- don't want to include them in
2247 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2248 entry = HeNEXT(entry);
2253 /* OK. Come to the end of the current list. Grab the next one. */
2255 iter->xhv_riter++; /* HvRITER(hv)++ */
2256 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2257 /* There is no next one. End of the hash. */
2258 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2261 entry = (HvARRAY(hv))[iter->xhv_riter];
2263 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2264 /* If we have an entry, but it's a placeholder, don't count it.
2266 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2267 entry = HeNEXT(entry);
2269 /* Will loop again if this linked list starts NULL
2270 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2271 or if we run through it and find only placeholders. */
2274 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2276 hv_free_ent(hv, oldentry);
2279 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2280 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
2282 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2287 =for apidoc hv_iterkey
2289 Returns the key from the current position of the hash iterator. See
2296 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2298 if (HeKLEN(entry) == HEf_SVKEY) {
2300 char * const p = SvPV(HeKEY_sv(entry), len);
2305 *retlen = HeKLEN(entry);
2306 return HeKEY(entry);
2310 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2312 =for apidoc hv_iterkeysv
2314 Returns the key as an C<SV*> from the current position of the hash
2315 iterator. The return value will always be a mortal copy of the key. Also
2322 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2324 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2328 =for apidoc hv_iterval
2330 Returns the value from the current position of the hash iterator. See
2337 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2339 if (SvRMAGICAL(hv)) {
2340 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2341 SV* const sv = sv_newmortal();
2342 if (HeKLEN(entry) == HEf_SVKEY)
2343 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2345 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2349 return HeVAL(entry);
2353 =for apidoc hv_iternextsv
2355 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2362 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2364 HE * const he = hv_iternext_flags(hv, 0);
2368 *key = hv_iterkey(he, retlen);
2369 return hv_iterval(hv, he);
2376 =for apidoc hv_magic
2378 Adds magic to a hash. See C<sv_magic>.
2383 /* possibly free a shared string if no one has access to it
2384 * len and hash must both be valid for str.
2387 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2389 unshare_hek_or_pvn (NULL, str, len, hash);
2394 Perl_unshare_hek(pTHX_ HEK *hek)
2396 unshare_hek_or_pvn(hek, NULL, 0, 0);
2399 /* possibly free a shared string if no one has access to it
2400 hek if non-NULL takes priority over the other 3, else str, len and hash
2401 are used. If so, len and hash must both be valid for str.
2404 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2407 register XPVHV* xhv;
2409 register HE **oentry;
2411 bool is_utf8 = FALSE;
2413 const char * const save = str;
2414 struct shared_he *he = NULL;
2417 /* Find the shared he which is just before us in memory. */
2418 he = (struct shared_he *)(((char *)hek)
2419 - STRUCT_OFFSET(struct shared_he,
2422 /* Assert that the caller passed us a genuine (or at least consistent)
2424 assert (he->shared_he_he.hent_hek == hek);
2427 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2428 --he->shared_he_he.he_valu.hent_refcount;
2429 UNLOCK_STRTAB_MUTEX;
2432 UNLOCK_STRTAB_MUTEX;
2434 hash = HEK_HASH(hek);
2435 } else if (len < 0) {
2436 STRLEN tmplen = -len;
2438 /* See the note in hv_fetch(). --jhi */
2439 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2442 k_flags = HVhek_UTF8;
2444 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2447 /* what follows was the moral equivalent of:
2448 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2450 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2452 xhv = (XPVHV*)SvANY(PL_strtab);
2453 /* assert(xhv_array != 0) */
2455 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2457 const HE *const he_he = &(he->shared_he_he);
2458 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2463 const int flags_masked = k_flags & HVhek_MASK;
2464 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2465 if (HeHASH(entry) != hash) /* strings can't be equal */
2467 if (HeKLEN(entry) != len)
2469 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2471 if (HeKFLAGS(entry) != flags_masked)
2478 if (--entry->he_valu.hent_refcount == 0) {
2479 *oentry = HeNEXT(entry);
2481 /* There are now no entries in our slot. */
2482 xhv->xhv_fill--; /* HvFILL(hv)-- */
2485 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2489 UNLOCK_STRTAB_MUTEX;
2490 if (!entry && ckWARN_d(WARN_INTERNAL))
2491 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2492 "Attempt to free non-existent shared string '%s'%s"
2494 hek ? HEK_KEY(hek) : str,
2495 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2496 if (k_flags & HVhek_FREEKEY)
2500 /* get a (constant) string ptr from the global string table
2501 * string will get added if it is not already there.
2502 * len and hash must both be valid for str.
2505 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2507 bool is_utf8 = FALSE;
2509 const char * const save = str;
2512 STRLEN tmplen = -len;
2514 /* See the note in hv_fetch(). --jhi */
2515 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2517 /* If we were able to downgrade here, then than means that we were passed
2518 in a key which only had chars 0-255, but was utf8 encoded. */
2521 /* If we found we were able to downgrade the string to bytes, then
2522 we should flag that it needs upgrading on keys or each. Also flag
2523 that we need share_hek_flags to free the string. */
2525 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2528 return share_hek_flags (str, len, hash, flags);
2532 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2536 const int flags_masked = flags & HVhek_MASK;
2537 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2539 /* what follows is the moral equivalent of:
2541 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2542 hv_store(PL_strtab, str, len, NULL, hash);
2544 Can't rehash the shared string table, so not sure if it's worth
2545 counting the number of entries in the linked list
2547 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2548 /* assert(xhv_array != 0) */
2550 entry = (HvARRAY(PL_strtab))[hindex];
2551 for (;entry; entry = HeNEXT(entry)) {
2552 if (HeHASH(entry) != hash) /* strings can't be equal */
2554 if (HeKLEN(entry) != len)
2556 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2558 if (HeKFLAGS(entry) != flags_masked)
2564 /* What used to be head of the list.
2565 If this is NULL, then we're the first entry for this slot, which
2566 means we need to increate fill. */
2567 struct shared_he *new_entry;
2570 HE **const head = &HvARRAY(PL_strtab)[hindex];
2571 HE *const next = *head;
2573 /* We don't actually store a HE from the arena and a regular HEK.
2574 Instead we allocate one chunk of memory big enough for both,
2575 and put the HEK straight after the HE. This way we can find the
2576 HEK directly from the HE.
2579 Newx(k, STRUCT_OFFSET(struct shared_he,
2580 shared_he_hek.hek_key[0]) + len + 2, char);
2581 new_entry = (struct shared_he *)k;
2582 entry = &(new_entry->shared_he_he);
2583 hek = &(new_entry->shared_he_hek);
2585 Copy(str, HEK_KEY(hek), len, char);
2586 HEK_KEY(hek)[len] = 0;
2588 HEK_HASH(hek) = hash;
2589 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2591 /* Still "point" to the HEK, so that other code need not know what
2593 HeKEY_hek(entry) = hek;
2594 entry->he_valu.hent_refcount = 0;
2595 HeNEXT(entry) = next;
2598 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2599 if (!next) { /* initial entry? */
2600 xhv->xhv_fill++; /* HvFILL(hv)++ */
2601 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2606 ++entry->he_valu.hent_refcount;
2607 UNLOCK_STRTAB_MUTEX;
2609 if (flags & HVhek_FREEKEY)
2612 return HeKEY_hek(entry);
2616 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2619 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2620 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2621 if (uf->uf_set == NULL) {
2622 SV* obj = mg->mg_obj;
2623 mg->mg_obj = keysv; /* pass key */
2624 uf->uf_index = action; /* pass action */
2625 magic_getuvar((SV*)hv, mg);
2626 keysv = mg->mg_obj; /* may have changed */
2634 Perl_hv_placeholders_p(pTHX_ HV *hv)
2637 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2640 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2643 Perl_die(aTHX_ "panic: hv_placeholders_p");
2646 return &(mg->mg_len);
2651 Perl_hv_placeholders_get(pTHX_ HV *hv)
2654 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2656 return mg ? mg->mg_len : 0;
2660 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2663 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2668 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2669 Perl_die(aTHX_ "panic: hv_placeholders_set");
2671 /* else we don't need to add magic to record 0 placeholders. */
2675 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2679 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2684 value = &PL_sv_placeholder;
2687 value = (he->refcounted_he_data[0] & HVrhek_UV)
2688 ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
2689 : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
2692 /* Create a string SV that directly points to the bytes in our
2695 sv_upgrade(value, SVt_PV);
2696 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2697 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2698 /* This stops anything trying to free it */
2699 SvLEN_set(value, 0);
2701 SvREADONLY_on(value);
2702 if (he->refcounted_he_data[0] & HVrhek_UTF8)
2706 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2707 he->refcounted_he_data[0]);
2713 /* A big expression to find the key offset */
2714 #define REF_HE_KEY(chain) \
2715 ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
2716 ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
2717 + 1 + chain->refcounted_he_data)
2721 =for apidoc refcounted_he_chain_2hv
2723 Generates an returns a C<HV *> by walking up the tree starting at the passed
2724 in C<struct refcounted_he *>.
2729 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2733 U32 placeholders = 0;
2734 /* We could chase the chain once to get an idea of the number of keys,
2735 and call ksplit. But for now we'll make a potentially inefficient
2736 hash with only 8 entries in its array. */
2737 const U32 max = HvMAX(hv);
2741 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2742 HvARRAY(hv) = (HE**)array;
2747 U32 hash = chain->refcounted_he_hash;
2749 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2751 HE **oentry = &((HvARRAY(hv))[hash & max]);
2752 HE *entry = *oentry;
2755 for (; entry; entry = HeNEXT(entry)) {
2756 if (HeHASH(entry) == hash) {
2757 /* We might have a duplicate key here. If so, entry is older
2758 than the key we've already put in the hash, so if they are
2759 the same, skip adding entry. */
2761 const STRLEN klen = HeKLEN(entry);
2762 const char *const key = HeKEY(entry);
2763 if (klen == chain->refcounted_he_keylen
2764 && (!!HeKUTF8(entry)
2765 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2766 && memEQ(key, REF_HE_KEY(chain), klen))
2769 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2771 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2772 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2773 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2784 = share_hek_flags(REF_HE_KEY(chain),
2785 chain->refcounted_he_keylen,
2786 chain->refcounted_he_hash,
2787 (chain->refcounted_he_data[0]
2788 & (HVhek_UTF8|HVhek_WASUTF8)));
2790 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2792 value = refcounted_he_value(chain);
2793 if (value == &PL_sv_placeholder)
2795 HeVAL(entry) = value;
2797 /* Link it into the chain. */
2798 HeNEXT(entry) = *oentry;
2799 if (!HeNEXT(entry)) {
2800 /* initial entry. */
2808 chain = chain->refcounted_he_next;
2812 clear_placeholders(hv, placeholders);
2813 HvTOTALKEYS(hv) -= placeholders;
2816 /* We could check in the loop to see if we encounter any keys with key
2817 flags, but it's probably not worth it, as this per-hash flag is only
2818 really meant as an optimisation for things like Storable. */
2820 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2826 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2827 const char *key, STRLEN klen, int flags, U32 hash)
2830 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2831 of your key has to exactly match that which is stored. */
2832 SV *value = &PL_sv_placeholder;
2836 if (flags & HVhek_FREEKEY)
2838 key = SvPV_const(keysv, klen);
2840 is_utf8 = (SvUTF8(keysv) != 0);
2842 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2846 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2847 hash = SvSHARED_HASH(keysv);
2849 PERL_HASH(hash, key, klen);
2853 for (; chain; chain = chain->refcounted_he_next) {
2855 if (hash != chain->refcounted_he_hash)
2857 if (klen != chain->refcounted_he_keylen)
2859 if (memNE(REF_HE_KEY(chain),key,klen))
2861 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2864 if (hash != HEK_HASH(chain->refcounted_he_hek))
2866 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2868 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2870 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2874 value = sv_2mortal(refcounted_he_value(chain));
2878 if (flags & HVhek_FREEKEY)
2885 =for apidoc refcounted_he_new
2887 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2888 stored in a compact form, all references remain the property of the caller.
2889 The C<struct refcounted_he> is returned with a reference count of 1.
2894 struct refcounted_he *
2895 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2896 SV *const key, SV *const value) {
2898 struct refcounted_he *he;
2900 const char *key_p = SvPV_const(key, key_len);
2901 STRLEN value_len = 0;
2902 const char *value_p = NULL;
2907 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2910 value_type = HVrhek_PV;
2911 } else if (SvIOK(value)) {
2912 value_type = HVrhek_IV;
2913 } else if (value == &PL_sv_placeholder) {
2914 value_type = HVrhek_delete;
2915 } else if (!SvOK(value)) {
2916 value_type = HVrhek_undef;
2918 value_type = HVrhek_PV;
2921 if (value_type == HVrhek_PV) {
2922 value_p = SvPV_const(value, value_len);
2923 key_offset = value_len + 2;
2931 he = (struct refcounted_he*)
2932 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2936 he = (struct refcounted_he*)
2937 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2942 he->refcounted_he_next = parent;
2944 if (value_type == HVrhek_PV) {
2945 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2946 he->refcounted_he_val.refcounted_he_u_len = value_len;
2947 if (SvUTF8(value)) {
2948 flags |= HVrhek_UTF8;
2950 } else if (value_type == HVrhek_IV) {
2952 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2955 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2960 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2961 As we're going to be building hash keys from this value in future,
2962 normalise it now. */
2963 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2964 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2966 PERL_HASH(hash, key_p, key_len);
2969 he->refcounted_he_hash = hash;
2970 he->refcounted_he_keylen = key_len;
2971 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2973 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2976 if (flags & HVhek_WASUTF8) {
2977 /* If it was downgraded from UTF-8, then the pointer returned from
2978 bytes_from_utf8 is an allocated pointer that we must free. */
2982 he->refcounted_he_data[0] = flags;
2983 he->refcounted_he_refcnt = 1;
2989 =for apidoc refcounted_he_free
2991 Decrements the reference count of the passed in C<struct refcounted_he *>
2992 by one. If the reference count reaches zero the structure's memory is freed,
2993 and C<refcounted_he_free> iterates onto the parent node.
2999 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3000 PERL_UNUSED_CONTEXT;
3003 struct refcounted_he *copy;
3007 new_count = --he->refcounted_he_refcnt;
3008 HINTS_REFCNT_UNLOCK;
3014 #ifndef USE_ITHREADS
3015 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3018 he = he->refcounted_he_next;
3019 PerlMemShared_free(copy);
3024 =for apidoc hv_assert
3026 Check that a hash is in an internally consistent state.
3034 Perl_hv_assert(pTHX_ HV *hv)
3039 int placeholders = 0;
3042 const I32 riter = HvRITER_get(hv);
3043 HE *eiter = HvEITER_get(hv);
3045 (void)hv_iterinit(hv);
3047 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3048 /* sanity check the values */
3049 if (HeVAL(entry) == &PL_sv_placeholder)
3053 /* sanity check the keys */
3054 if (HeSVKEY(entry)) {
3055 NOOP; /* Don't know what to check on SV keys. */
3056 } else if (HeKUTF8(entry)) {
3058 if (HeKWASUTF8(entry)) {
3059 PerlIO_printf(Perl_debug_log,
3060 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
3061 (int) HeKLEN(entry), HeKEY(entry));
3064 } else if (HeKWASUTF8(entry))
3067 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
3068 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3069 const int nhashkeys = HvUSEDKEYS(hv);
3070 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3072 if (nhashkeys != real) {
3073 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3076 if (nhashplaceholders != placeholders) {
3077 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3081 if (withflags && ! HvHASKFLAGS(hv)) {
3082 PerlIO_printf(Perl_debug_log,
3083 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3090 HvRITER_set(hv, riter); /* Restore hash iterator state */
3091 HvEITER_set(hv, eiter);
3098 * c-indentation-style: bsd
3100 * indent-tabs-mode: t
3103 * ex: set ts=8 sts=4 sw=4 noet: