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 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
456 /* XXX should be able to skimp on the HE/HEK here when
457 HV_FETCH_JUST_SV is true. */
460 keysv = newSVpvn(key, klen);
465 keysv = newSVsv(keysv);
467 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
469 /* grab a fake HE/HEK pair from the pool or make a new one */
470 entry = PL_hv_fetch_ent_mh;
472 PL_hv_fetch_ent_mh = HeNEXT(entry);
476 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
477 HeKEY_hek(entry) = (HEK*)k;
479 HeNEXT(entry) = NULL;
480 HeSVKEY_set(entry, keysv);
482 sv_upgrade(sv, SVt_PVLV);
484 /* so we can free entry when freeing sv */
485 LvTARG(sv) = (SV*)entry;
487 /* XXX remove at some point? */
488 if (flags & HVhek_FREEKEY)
493 #ifdef ENV_IS_CASELESS
494 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
496 for (i = 0; i < klen; ++i)
497 if (isLOWER(key[i])) {
498 /* Would be nice if we had a routine to do the
499 copy and upercase in a single pass through. */
500 const char * const nkey = strupr(savepvn(key,klen));
501 /* Note that this fetch is for nkey (the uppercased
502 key) whereas the store is for key (the original) */
503 entry = hv_fetch_common(hv, NULL, nkey, klen,
504 HVhek_FREEKEY, /* free nkey */
505 0 /* non-LVAL fetch */,
507 0 /* compute hash */);
508 if (!entry && (action & HV_FETCH_LVALUE)) {
509 /* This call will free key if necessary.
510 Do it this way to encourage compiler to tail
512 entry = hv_fetch_common(hv, keysv, key, klen,
513 flags, HV_FETCH_ISSTORE,
516 if (flags & HVhek_FREEKEY)
524 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
525 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
526 /* I don't understand why hv_exists_ent has svret and sv,
527 whereas hv_exists only had one. */
528 SV * const svret = sv_newmortal();
531 if (keysv || is_utf8) {
533 keysv = newSVpvn(key, klen);
536 keysv = newSVsv(keysv);
538 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
540 mg_copy((SV*)hv, sv, key, klen);
542 if (flags & HVhek_FREEKEY)
544 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
545 /* This cast somewhat evil, but I'm merely using NULL/
546 not NULL to return the boolean exists.
547 And I know hv is not NULL. */
548 return SvTRUE(svret) ? (HE *)hv : NULL;
550 #ifdef ENV_IS_CASELESS
551 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
552 /* XXX This code isn't UTF8 clean. */
553 char * const keysave = (char * const)key;
554 /* Will need to free this, so set FREEKEY flag. */
555 key = savepvn(key,klen);
556 key = (const char*)strupr((char*)key);
561 if (flags & HVhek_FREEKEY) {
564 flags |= HVhek_FREEKEY;
568 else if (action & HV_FETCH_ISSTORE) {
571 hv_magic_check (hv, &needs_copy, &needs_store);
573 const bool save_taint = PL_tainted;
574 if (keysv || is_utf8) {
576 keysv = newSVpvn(key, klen);
580 PL_tainted = SvTAINTED(keysv);
581 keysv = sv_2mortal(newSVsv(keysv));
582 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
584 mg_copy((SV*)hv, val, key, klen);
587 TAINT_IF(save_taint);
589 if (flags & HVhek_FREEKEY)
593 #ifdef ENV_IS_CASELESS
594 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
595 /* XXX This code isn't UTF8 clean. */
596 const char *keysave = key;
597 /* Will need to free this, so set FREEKEY flag. */
598 key = savepvn(key,klen);
599 key = (const char*)strupr((char*)key);
604 if (flags & HVhek_FREEKEY) {
607 flags |= HVhek_FREEKEY;
615 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
616 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
617 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
622 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
624 HvARRAY(hv) = (HE**)array;
626 #ifdef DYNAMIC_ENV_FETCH
627 else if (action & HV_FETCH_ISEXISTS) {
628 /* for an %ENV exists, if we do an insert it's by a recursive
629 store call, so avoid creating HvARRAY(hv) right now. */
633 /* XXX remove at some point? */
634 if (flags & HVhek_FREEKEY)
642 char * const keysave = (char *)key;
643 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
647 flags &= ~HVhek_UTF8;
648 if (key != keysave) {
649 if (flags & HVhek_FREEKEY)
651 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
656 PERL_HASH_INTERNAL(hash, key, klen);
657 /* We don't have a pointer to the hv, so we have to replicate the
658 flag into every HEK, so that hv_iterkeysv can see it. */
659 /* And yes, you do need this even though you are not "storing" because
660 you can flip the flags below if doing an lval lookup. (And that
661 was put in to give the semantics Andreas was expecting.) */
662 flags |= HVhek_REHASH;
664 if (keysv && (SvIsCOW_shared_hash(keysv))) {
665 hash = SvSHARED_HASH(keysv);
667 PERL_HASH(hash, key, klen);
671 masked_flags = (flags & HVhek_MASK);
673 #ifdef DYNAMIC_ENV_FETCH
674 if (!HvARRAY(hv)) entry = NULL;
678 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
680 for (; entry; entry = HeNEXT(entry)) {
681 if (HeHASH(entry) != hash) /* strings can't be equal */
683 if (HeKLEN(entry) != (I32)klen)
685 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
687 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
690 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
691 if (HeKFLAGS(entry) != masked_flags) {
692 /* We match if HVhek_UTF8 bit in our flags and hash key's
693 match. But if entry was set previously with HVhek_WASUTF8
694 and key now doesn't (or vice versa) then we should change
695 the key's flag, as this is assignment. */
696 if (HvSHAREKEYS(hv)) {
697 /* Need to swap the key we have for a key with the flags we
698 need. As keys are shared we can't just write to the
699 flag, so we share the new one, unshare the old one. */
700 HEK * const new_hek = share_hek_flags(key, klen, hash,
702 unshare_hek (HeKEY_hek(entry));
703 HeKEY_hek(entry) = new_hek;
705 else if (hv == PL_strtab) {
706 /* PL_strtab is usually the only hash without HvSHAREKEYS,
707 so putting this test here is cheap */
708 if (flags & HVhek_FREEKEY)
710 Perl_croak(aTHX_ S_strtab_error,
711 action & HV_FETCH_LVALUE ? "fetch" : "store");
714 HeKFLAGS(entry) = masked_flags;
715 if (masked_flags & HVhek_ENABLEHVKFLAGS)
718 if (HeVAL(entry) == &PL_sv_placeholder) {
719 /* yes, can store into placeholder slot */
720 if (action & HV_FETCH_LVALUE) {
722 /* This preserves behaviour with the old hv_fetch
723 implementation which at this point would bail out
724 with a break; (at "if we find a placeholder, we
725 pretend we haven't found anything")
727 That break mean that if a placeholder were found, it
728 caused a call into hv_store, which in turn would
729 check magic, and if there is no magic end up pretty
730 much back at this point (in hv_store's code). */
733 /* LVAL fetch which actaully needs a store. */
735 HvPLACEHOLDERS(hv)--;
738 if (val != &PL_sv_placeholder)
739 HvPLACEHOLDERS(hv)--;
742 } else if (action & HV_FETCH_ISSTORE) {
743 SvREFCNT_dec(HeVAL(entry));
746 } else if (HeVAL(entry) == &PL_sv_placeholder) {
747 /* if we find a placeholder, we pretend we haven't found
751 if (flags & HVhek_FREEKEY)
755 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
756 if (!(action & HV_FETCH_ISSTORE)
757 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
759 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
761 sv = newSVpvn(env,len);
763 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
769 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
770 hv_notallowed(flags, key, klen,
771 "Attempt to access disallowed key '%"SVf"' in"
772 " a restricted hash");
774 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
775 /* Not doing some form of store, so return failure. */
776 if (flags & HVhek_FREEKEY)
780 if (action & HV_FETCH_LVALUE) {
783 /* At this point the old hv_fetch code would call to hv_store,
784 which in turn might do some tied magic. So we need to make that
785 magic check happen. */
786 /* gonna assign to this, so it better be there */
787 return hv_fetch_common(hv, keysv, key, klen, flags,
788 HV_FETCH_ISSTORE, val, hash);
789 /* XXX Surely that could leak if the fetch-was-store fails?
790 Just like the hv_fetch. */
794 /* Welcome to hv_store... */
797 /* Not sure if we can get here. I think the only case of oentry being
798 NULL is for %ENV with dynamic env fetch. But that should disappear
799 with magic in the previous code. */
802 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
804 HvARRAY(hv) = (HE**)array;
807 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
810 /* share_hek_flags will do the free for us. This might be considered
813 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
814 else if (hv == PL_strtab) {
815 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
816 this test here is cheap */
817 if (flags & HVhek_FREEKEY)
819 Perl_croak(aTHX_ S_strtab_error,
820 action & HV_FETCH_LVALUE ? "fetch" : "store");
822 else /* gotta do the real thing */
823 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
825 HeNEXT(entry) = *oentry;
828 if (val == &PL_sv_placeholder)
829 HvPLACEHOLDERS(hv)++;
830 if (masked_flags & HVhek_ENABLEHVKFLAGS)
834 const HE *counter = HeNEXT(entry);
836 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
837 if (!counter) { /* initial entry? */
838 xhv->xhv_fill++; /* HvFILL(hv)++ */
839 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
841 } else if(!HvREHASH(hv)) {
844 while ((counter = HeNEXT(counter)))
847 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
848 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
849 bucket splits on a rehashed hash, as we're not going to
850 split it again, and if someone is lucky (evil) enough to
851 get all the keys in one list they could exhaust our memory
852 as we repeatedly double the number of buckets on every
853 entry. Linear search feels a less worse thing to do. */
863 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
865 const MAGIC *mg = SvMAGIC(hv);
869 if (isUPPER(mg->mg_type)) {
871 if (mg->mg_type == PERL_MAGIC_tied) {
872 *needs_store = FALSE;
873 return; /* We've set all there is to set. */
876 mg = mg->mg_moremagic;
881 =for apidoc hv_scalar
883 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
889 Perl_hv_scalar(pTHX_ HV *hv)
893 if (SvRMAGICAL(hv)) {
894 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
896 return magic_scalarpack(hv, mg);
901 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
902 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
910 =for apidoc hv_delete
912 Deletes a key/value pair in the hash. The value SV is removed from the
913 hash and returned to the caller. The C<klen> is the length of the key.
914 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
921 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
928 k_flags = HVhek_UTF8;
933 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
937 =for apidoc hv_delete_ent
939 Deletes a key/value pair in the hash. The value SV is removed from the
940 hash and returned to the caller. The C<flags> value will normally be zero;
941 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
942 precomputed hash value, or 0 to ask for it to be computed.
947 /* XXX This looks like an ideal candidate to inline */
949 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
951 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
955 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
956 int k_flags, I32 d_flags, U32 hash)
961 register HE **oentry;
962 HE *const *first_entry;
970 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
971 keysv = hv_magic_uvar_xkey(hv, keysv, -1);
972 if (k_flags & HVhek_FREEKEY)
974 key = SvPV_const(keysv, klen);
976 is_utf8 = (SvUTF8(keysv) != 0);
978 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
981 if (SvRMAGICAL(hv)) {
984 hv_magic_check (hv, &needs_copy, &needs_store);
988 entry = hv_fetch_common(hv, keysv, key, klen,
989 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
991 sv = entry ? HeVAL(entry) : NULL;
997 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
998 /* No longer an element */
999 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1002 return NULL; /* element cannot be deleted */
1004 #ifdef ENV_IS_CASELESS
1005 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1006 /* XXX This code isn't UTF8 clean. */
1007 keysv = sv_2mortal(newSVpvn(key,klen));
1008 if (k_flags & HVhek_FREEKEY) {
1011 key = strupr(SvPVX(keysv));
1020 xhv = (XPVHV*)SvANY(hv);
1025 const char * const keysave = key;
1026 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1029 k_flags |= HVhek_UTF8;
1031 k_flags &= ~HVhek_UTF8;
1032 if (key != keysave) {
1033 if (k_flags & HVhek_FREEKEY) {
1034 /* This shouldn't happen if our caller does what we expect,
1035 but strictly the API allows it. */
1038 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1040 HvHASKFLAGS_on((SV*)hv);
1044 PERL_HASH_INTERNAL(hash, key, klen);
1046 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1047 hash = SvSHARED_HASH(keysv);
1049 PERL_HASH(hash, key, klen);
1053 masked_flags = (k_flags & HVhek_MASK);
1055 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1057 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1059 if (HeHASH(entry) != hash) /* strings can't be equal */
1061 if (HeKLEN(entry) != (I32)klen)
1063 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1065 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1068 if (hv == PL_strtab) {
1069 if (k_flags & HVhek_FREEKEY)
1071 Perl_croak(aTHX_ S_strtab_error, "delete");
1074 /* if placeholder is here, it's already been deleted.... */
1075 if (HeVAL(entry) == &PL_sv_placeholder) {
1076 if (k_flags & HVhek_FREEKEY)
1080 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1081 hv_notallowed(k_flags, key, klen,
1082 "Attempt to delete readonly key '%"SVf"' from"
1083 " a restricted hash");
1085 if (k_flags & HVhek_FREEKEY)
1088 if (d_flags & G_DISCARD)
1091 sv = sv_2mortal(HeVAL(entry));
1092 HeVAL(entry) = &PL_sv_placeholder;
1096 * If a restricted hash, rather than really deleting the entry, put
1097 * a placeholder there. This marks the key as being "approved", so
1098 * we can still access via not-really-existing key without raising
1101 if (SvREADONLY(hv)) {
1102 SvREFCNT_dec(HeVAL(entry));
1103 HeVAL(entry) = &PL_sv_placeholder;
1104 /* We'll be saving this slot, so the number of allocated keys
1105 * doesn't go down, but the number placeholders goes up */
1106 HvPLACEHOLDERS(hv)++;
1108 *oentry = HeNEXT(entry);
1110 xhv->xhv_fill--; /* HvFILL(hv)-- */
1112 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1115 hv_free_ent(hv, entry);
1116 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1117 if (xhv->xhv_keys == 0)
1118 HvHASKFLAGS_off(hv);
1122 if (SvREADONLY(hv)) {
1123 hv_notallowed(k_flags, key, klen,
1124 "Attempt to delete disallowed key '%"SVf"' from"
1125 " a restricted hash");
1128 if (k_flags & HVhek_FREEKEY)
1134 S_hsplit(pTHX_ HV *hv)
1137 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1138 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1139 register I32 newsize = oldsize * 2;
1141 char *a = (char*) HvARRAY(hv);
1143 register HE **oentry;
1144 int longest_chain = 0;
1147 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1148 hv, (int) oldsize);*/
1150 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1151 /* Can make this clear any placeholders first for non-restricted hashes,
1152 even though Storable rebuilds restricted hashes by putting in all the
1153 placeholders (first) before turning on the readonly flag, because
1154 Storable always pre-splits the hash. */
1155 hv_clear_placeholders(hv);
1159 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1160 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1161 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1167 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1170 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1171 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1176 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1178 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1180 if (oldsize >= 64) {
1181 offer_nice_chunk(HvARRAY(hv),
1182 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1183 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1186 Safefree(HvARRAY(hv));
1190 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1191 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1192 HvARRAY(hv) = (HE**) a;
1195 for (i=0; i<oldsize; i++,aep++) {
1196 int left_length = 0;
1197 int right_length = 0;
1201 if (!*aep) /* non-existent */
1204 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1205 if ((HeHASH(entry) & newsize) != (U32)i) {
1206 *oentry = HeNEXT(entry);
1207 HeNEXT(entry) = *bep;
1209 xhv->xhv_fill++; /* HvFILL(hv)++ */
1215 oentry = &HeNEXT(entry);
1219 if (!*aep) /* everything moved */
1220 xhv->xhv_fill--; /* HvFILL(hv)-- */
1221 /* I think we don't actually need to keep track of the longest length,
1222 merely flag if anything is too long. But for the moment while
1223 developing this code I'll track it. */
1224 if (left_length > longest_chain)
1225 longest_chain = left_length;
1226 if (right_length > longest_chain)
1227 longest_chain = right_length;
1231 /* Pick your policy for "hashing isn't working" here: */
1232 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1237 if (hv == PL_strtab) {
1238 /* Urg. Someone is doing something nasty to the string table.
1243 /* Awooga. Awooga. Pathological data. */
1244 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", hv,
1245 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1248 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1249 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1251 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1254 was_shared = HvSHAREKEYS(hv);
1257 HvSHAREKEYS_off(hv);
1262 for (i=0; i<newsize; i++,aep++) {
1263 register HE *entry = *aep;
1265 /* We're going to trash this HE's next pointer when we chain it
1266 into the new hash below, so store where we go next. */
1267 HE * const next = HeNEXT(entry);
1272 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1277 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1278 hash, HeKFLAGS(entry));
1279 unshare_hek (HeKEY_hek(entry));
1280 HeKEY_hek(entry) = new_hek;
1282 /* Not shared, so simply write the new hash in. */
1283 HeHASH(entry) = hash;
1285 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1286 HEK_REHASH_on(HeKEY_hek(entry));
1287 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1289 /* Copy oentry to the correct new chain. */
1290 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1292 xhv->xhv_fill++; /* HvFILL(hv)++ */
1293 HeNEXT(entry) = *bep;
1299 Safefree (HvARRAY(hv));
1300 HvARRAY(hv) = (HE **)a;
1304 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1307 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1308 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1309 register I32 newsize;
1314 register HE **oentry;
1316 newsize = (I32) newmax; /* possible truncation here */
1317 if (newsize != newmax || newmax <= oldsize)
1319 while ((newsize & (1 + ~newsize)) != newsize) {
1320 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1322 if (newsize < newmax)
1324 if (newsize < newmax)
1325 return; /* overflow detection */
1327 a = (char *) HvARRAY(hv);
1330 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1331 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1332 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1338 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1341 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1342 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1347 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1349 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1351 if (oldsize >= 64) {
1352 offer_nice_chunk(HvARRAY(hv),
1353 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1354 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1357 Safefree(HvARRAY(hv));
1360 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1363 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1365 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1366 HvARRAY(hv) = (HE **) a;
1367 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1371 for (i=0; i<oldsize; i++,aep++) {
1372 if (!*aep) /* non-existent */
1374 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1375 register I32 j = (HeHASH(entry) & newsize);
1379 *oentry = HeNEXT(entry);
1380 if (!(HeNEXT(entry) = aep[j]))
1381 xhv->xhv_fill++; /* HvFILL(hv)++ */
1386 oentry = &HeNEXT(entry);
1388 if (!*aep) /* everything moved */
1389 xhv->xhv_fill--; /* HvFILL(hv)-- */
1396 Creates a new HV. The reference count is set to 1.
1404 register XPVHV* xhv;
1405 HV * const hv = (HV*)newSV(0);
1407 sv_upgrade((SV *)hv, SVt_PVHV);
1408 xhv = (XPVHV*)SvANY(hv);
1411 #ifndef NODEFAULT_SHAREKEYS
1412 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1415 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1416 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1421 Perl_newHVhv(pTHX_ HV *ohv)
1423 HV * const hv = newHV();
1424 STRLEN hv_max, hv_fill;
1426 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1428 hv_max = HvMAX(ohv);
1430 if (!SvMAGICAL((SV *)ohv)) {
1431 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1433 const bool shared = !!HvSHAREKEYS(ohv);
1434 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1436 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1439 /* In each bucket... */
1440 for (i = 0; i <= hv_max; i++) {
1442 HE *oent = oents[i];
1449 /* Copy the linked list of entries. */
1450 for (; oent; oent = HeNEXT(oent)) {
1451 const U32 hash = HeHASH(oent);
1452 const char * const key = HeKEY(oent);
1453 const STRLEN len = HeKLEN(oent);
1454 const int flags = HeKFLAGS(oent);
1455 HE * const ent = new_HE();
1457 HeVAL(ent) = newSVsv(HeVAL(oent));
1459 = shared ? share_hek_flags(key, len, hash, flags)
1460 : save_hek_flags(key, len, hash, flags);
1471 HvFILL(hv) = hv_fill;
1472 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1476 /* Iterate over ohv, copying keys and values one at a time. */
1478 const I32 riter = HvRITER_get(ohv);
1479 HE * const eiter = HvEITER_get(ohv);
1481 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1482 while (hv_max && hv_max + 1 >= hv_fill * 2)
1483 hv_max = hv_max / 2;
1487 while ((entry = hv_iternext_flags(ohv, 0))) {
1488 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1489 newSVsv(HeVAL(entry)), HeHASH(entry),
1492 HvRITER_set(ohv, riter);
1493 HvEITER_set(ohv, eiter);
1499 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1500 magic stays on it. */
1502 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1504 HV * const hv = newHV();
1507 if (ohv && (hv_fill = HvFILL(ohv))) {
1508 STRLEN hv_max = HvMAX(ohv);
1510 const I32 riter = HvRITER_get(ohv);
1511 HE * const eiter = HvEITER_get(ohv);
1513 while (hv_max && hv_max + 1 >= hv_fill * 2)
1514 hv_max = hv_max / 2;
1518 while ((entry = hv_iternext_flags(ohv, 0))) {
1519 SV *const sv = newSVsv(HeVAL(entry));
1520 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1521 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1522 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1523 sv, HeHASH(entry), HeKFLAGS(entry));
1525 HvRITER_set(ohv, riter);
1526 HvEITER_set(ohv, eiter);
1528 hv_magic(hv, NULL, PERL_MAGIC_hints);
1533 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1541 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1542 PL_sub_generation++; /* may be deletion of method from stash */
1544 if (HeKLEN(entry) == HEf_SVKEY) {
1545 SvREFCNT_dec(HeKEY_sv(entry));
1546 Safefree(HeKEY_hek(entry));
1548 else if (HvSHAREKEYS(hv))
1549 unshare_hek(HeKEY_hek(entry));
1551 Safefree(HeKEY_hek(entry));
1556 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1561 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1562 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1563 if (HeKLEN(entry) == HEf_SVKEY) {
1564 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1566 hv_free_ent(hv, entry);
1570 =for apidoc hv_clear
1572 Clears a hash, making it empty.
1578 Perl_hv_clear(pTHX_ HV *hv)
1581 register XPVHV* xhv;
1585 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1587 xhv = (XPVHV*)SvANY(hv);
1589 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1590 /* restricted hash: convert all keys to placeholders */
1592 for (i = 0; i <= xhv->xhv_max; i++) {
1593 HE *entry = (HvARRAY(hv))[i];
1594 for (; entry; entry = HeNEXT(entry)) {
1595 /* not already placeholder */
1596 if (HeVAL(entry) != &PL_sv_placeholder) {
1597 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1598 SV* const keysv = hv_iterkeysv(entry);
1600 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1603 SvREFCNT_dec(HeVAL(entry));
1604 HeVAL(entry) = &PL_sv_placeholder;
1605 HvPLACEHOLDERS(hv)++;
1613 HvPLACEHOLDERS_set(hv, 0);
1615 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1620 HvHASKFLAGS_off(hv);
1624 HvEITER_set(hv, NULL);
1629 =for apidoc hv_clear_placeholders
1631 Clears any placeholders from a hash. If a restricted hash has any of its keys
1632 marked as readonly and the key is subsequently deleted, the key is not actually
1633 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1634 it so it will be ignored by future operations such as iterating over the hash,
1635 but will still allow the hash to have a value reassigned to the key at some
1636 future point. This function clears any such placeholder keys from the hash.
1637 See Hash::Util::lock_keys() for an example of its use.
1643 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1646 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1649 clear_placeholders(hv, items);
1653 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1663 /* Loop down the linked list heads */
1665 HE **oentry = &(HvARRAY(hv))[i];
1668 while ((entry = *oentry)) {
1669 if (HeVAL(entry) == &PL_sv_placeholder) {
1670 *oentry = HeNEXT(entry);
1671 if (first && !*oentry)
1672 HvFILL(hv)--; /* This linked list is now empty. */
1673 if (entry == HvEITER_get(hv))
1676 hv_free_ent(hv, entry);
1680 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1681 if (HvKEYS(hv) == 0)
1682 HvHASKFLAGS_off(hv);
1683 HvPLACEHOLDERS_set(hv, 0);
1687 oentry = &HeNEXT(entry);
1692 /* You can't get here, hence assertion should always fail. */
1693 assert (items == 0);
1698 S_hfreeentries(pTHX_ HV *hv)
1700 /* This is the array that we're going to restore */
1709 /* If the hash is actually a symbol table with a name, look after the
1711 struct xpvhv_aux *iter = HvAUX(hv);
1713 name = iter->xhv_name;
1714 iter->xhv_name = NULL;
1719 orig_array = HvARRAY(hv);
1720 /* orig_array remains unchanged throughout the loop. If after freeing all
1721 the entries it turns out that one of the little blighters has triggered
1722 an action that has caused HvARRAY to be re-allocated, then we set
1723 array to the new HvARRAY, and try again. */
1726 /* This is the one we're going to try to empty. First time round
1727 it's the original array. (Hopefully there will only be 1 time
1729 HE ** const array = HvARRAY(hv);
1732 /* Because we have taken xhv_name out, the only allocated pointer
1733 in the aux structure that might exist is the backreference array.
1738 struct xpvhv_aux *iter = HvAUX(hv);
1739 /* If there are weak references to this HV, we need to avoid
1740 freeing them up here. In particular we need to keep the AV
1741 visible as what we're deleting might well have weak references
1742 back to this HV, so the for loop below may well trigger
1743 the removal of backreferences from this array. */
1745 if (iter->xhv_backreferences) {
1746 /* So donate them to regular backref magic to keep them safe.
1747 The sv_magic will increase the reference count of the AV,
1748 so we need to drop it first. */
1749 SvREFCNT_dec(iter->xhv_backreferences);
1750 if (AvFILLp(iter->xhv_backreferences) == -1) {
1751 /* Turns out that the array is empty. Just free it. */
1752 SvREFCNT_dec(iter->xhv_backreferences);
1755 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1756 PERL_MAGIC_backref, NULL, 0);
1758 iter->xhv_backreferences = NULL;
1761 entry = iter->xhv_eiter; /* HvEITER(hv) */
1762 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1764 hv_free_ent(hv, entry);
1766 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1767 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1769 /* There are now no allocated pointers in the aux structure. */
1771 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1772 /* What aux structure? */
1775 /* make everyone else think the array is empty, so that the destructors
1776 * called for freed entries can't recusively mess with us */
1779 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1783 /* Loop down the linked list heads */
1784 HE *entry = array[i];
1787 register HE * const oentry = entry;
1788 entry = HeNEXT(entry);
1789 hv_free_ent(hv, oentry);
1793 /* As there are no allocated pointers in the aux structure, it's now
1794 safe to free the array we just cleaned up, if it's not the one we're
1795 going to put back. */
1796 if (array != orig_array) {
1801 /* Good. No-one added anything this time round. */
1806 /* Someone attempted to iterate or set the hash name while we had
1807 the array set to 0. We'll catch backferences on the next time
1808 round the while loop. */
1809 assert(HvARRAY(hv));
1811 if (HvAUX(hv)->xhv_name) {
1812 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1816 if (--attempts == 0) {
1817 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1821 HvARRAY(hv) = orig_array;
1823 /* If the hash was actually a symbol table, put the name back. */
1825 /* We have restored the original array. If name is non-NULL, then
1826 the original array had an aux structure at the end. So this is
1828 SvFLAGS(hv) |= SVf_OOK;
1829 HvAUX(hv)->xhv_name = name;
1834 =for apidoc hv_undef
1842 Perl_hv_undef(pTHX_ HV *hv)
1845 register XPVHV* xhv;
1850 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1851 xhv = (XPVHV*)SvANY(hv);
1853 if ((name = HvNAME_get(hv))) {
1855 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1856 hv_name_set(hv, NULL, 0, 0);
1858 SvFLAGS(hv) &= ~SVf_OOK;
1859 Safefree(HvARRAY(hv));
1860 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1862 HvPLACEHOLDERS_set(hv, 0);
1868 static struct xpvhv_aux*
1869 S_hv_auxinit(HV *hv) {
1870 struct xpvhv_aux *iter;
1874 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1875 + sizeof(struct xpvhv_aux), char);
1877 array = (char *) HvARRAY(hv);
1878 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1879 + sizeof(struct xpvhv_aux), char);
1881 HvARRAY(hv) = (HE**) array;
1882 /* SvOOK_on(hv) attacks the IV flags. */
1883 SvFLAGS(hv) |= SVf_OOK;
1886 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1887 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1889 iter->xhv_backreferences = 0;
1894 =for apidoc hv_iterinit
1896 Prepares a starting point to traverse a hash table. Returns the number of
1897 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1898 currently only meaningful for hashes without tie magic.
1900 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1901 hash buckets that happen to be in use. If you still need that esoteric
1902 value, you can get it through the macro C<HvFILL(tb)>.
1909 Perl_hv_iterinit(pTHX_ HV *hv)
1912 Perl_croak(aTHX_ "Bad hash");
1915 struct xpvhv_aux * const iter = HvAUX(hv);
1916 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1917 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1919 hv_free_ent(hv, entry);
1921 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1922 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1927 /* used to be xhv->xhv_fill before 5.004_65 */
1928 return HvTOTALKEYS(hv);
1932 Perl_hv_riter_p(pTHX_ HV *hv) {
1933 struct xpvhv_aux *iter;
1936 Perl_croak(aTHX_ "Bad hash");
1938 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1939 return &(iter->xhv_riter);
1943 Perl_hv_eiter_p(pTHX_ HV *hv) {
1944 struct xpvhv_aux *iter;
1947 Perl_croak(aTHX_ "Bad hash");
1949 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1950 return &(iter->xhv_eiter);
1954 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1955 struct xpvhv_aux *iter;
1958 Perl_croak(aTHX_ "Bad hash");
1966 iter = hv_auxinit(hv);
1968 iter->xhv_riter = riter;
1972 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1973 struct xpvhv_aux *iter;
1976 Perl_croak(aTHX_ "Bad hash");
1981 /* 0 is the default so don't go malloc()ing a new structure just to
1986 iter = hv_auxinit(hv);
1988 iter->xhv_eiter = eiter;
1992 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1995 struct xpvhv_aux *iter;
1998 PERL_UNUSED_ARG(flags);
2001 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2005 if (iter->xhv_name) {
2006 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2012 iter = hv_auxinit(hv);
2014 PERL_HASH(hash, name, len);
2015 iter->xhv_name = name ? share_hek(name, len, hash) : 0;
2019 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2020 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2021 PERL_UNUSED_CONTEXT;
2022 return &(iter->xhv_backreferences);
2026 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2032 av = HvAUX(hv)->xhv_backreferences;
2035 HvAUX(hv)->xhv_backreferences = 0;
2036 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2041 hv_iternext is implemented as a macro in hv.h
2043 =for apidoc hv_iternext
2045 Returns entries from a hash iterator. See C<hv_iterinit>.
2047 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2048 iterator currently points to, without losing your place or invalidating your
2049 iterator. Note that in this case the current entry is deleted from the hash
2050 with your iterator holding the last reference to it. Your iterator is flagged
2051 to free the entry on the next call to C<hv_iternext>, so you must not discard
2052 your iterator immediately else the entry will leak - call C<hv_iternext> to
2053 trigger the resource deallocation.
2055 =for apidoc hv_iternext_flags
2057 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2058 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2059 set the placeholders keys (for restricted hashes) will be returned in addition
2060 to normal keys. By default placeholders are automatically skipped over.
2061 Currently a placeholder is implemented with a value that is
2062 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2063 restricted hashes may change, and the implementation currently is
2064 insufficiently abstracted for any change to be tidy.
2070 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2073 register XPVHV* xhv;
2077 struct xpvhv_aux *iter;
2080 Perl_croak(aTHX_ "Bad hash");
2081 xhv = (XPVHV*)SvANY(hv);
2084 /* Too many things (well, pp_each at least) merrily assume that you can
2085 call iv_iternext without calling hv_iterinit, so we'll have to deal
2091 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2093 if ((mg = SvTIED_mg((SV*)hv, PERL_MAGIC_tied))) {
2094 SV * const key = sv_newmortal();
2096 sv_setsv(key, HeSVKEY_force(entry));
2097 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2103 /* one HE per MAGICAL hash */
2104 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2106 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2108 HeKEY_hek(entry) = hek;
2109 HeKLEN(entry) = HEf_SVKEY;
2111 magic_nextpack((SV*) hv,mg,key);
2113 /* force key to stay around until next time */
2114 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2115 return entry; /* beware, hent_val is not set */
2118 SvREFCNT_dec(HeVAL(entry));
2119 Safefree(HeKEY_hek(entry));
2121 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2124 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2125 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2128 /* The prime_env_iter() on VMS just loaded up new hash values
2129 * so the iteration count needs to be reset back to the beginning
2133 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2138 /* hv_iterint now ensures this. */
2139 assert (HvARRAY(hv));
2141 /* At start of hash, entry is NULL. */
2144 entry = HeNEXT(entry);
2145 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2147 * Skip past any placeholders -- don't want to include them in
2150 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2151 entry = HeNEXT(entry);
2156 /* OK. Come to the end of the current list. Grab the next one. */
2158 iter->xhv_riter++; /* HvRITER(hv)++ */
2159 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2160 /* There is no next one. End of the hash. */
2161 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2164 entry = (HvARRAY(hv))[iter->xhv_riter];
2166 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2167 /* If we have an entry, but it's a placeholder, don't count it.
2169 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2170 entry = HeNEXT(entry);
2172 /* Will loop again if this linked list starts NULL
2173 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2174 or if we run through it and find only placeholders. */
2177 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2179 hv_free_ent(hv, oldentry);
2182 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2183 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", hv, entry);*/
2185 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2190 =for apidoc hv_iterkey
2192 Returns the key from the current position of the hash iterator. See
2199 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2201 if (HeKLEN(entry) == HEf_SVKEY) {
2203 char * const p = SvPV(HeKEY_sv(entry), len);
2208 *retlen = HeKLEN(entry);
2209 return HeKEY(entry);
2213 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2215 =for apidoc hv_iterkeysv
2217 Returns the key as an C<SV*> from the current position of the hash
2218 iterator. The return value will always be a mortal copy of the key. Also
2225 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2227 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2231 =for apidoc hv_iterval
2233 Returns the value from the current position of the hash iterator. See
2240 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2242 if (SvRMAGICAL(hv)) {
2243 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2244 SV* const sv = sv_newmortal();
2245 if (HeKLEN(entry) == HEf_SVKEY)
2246 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2248 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2252 return HeVAL(entry);
2256 =for apidoc hv_iternextsv
2258 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2265 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2267 HE * const he = hv_iternext_flags(hv, 0);
2271 *key = hv_iterkey(he, retlen);
2272 return hv_iterval(hv, he);
2279 =for apidoc hv_magic
2281 Adds magic to a hash. See C<sv_magic>.
2286 /* possibly free a shared string if no one has access to it
2287 * len and hash must both be valid for str.
2290 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2292 unshare_hek_or_pvn (NULL, str, len, hash);
2297 Perl_unshare_hek(pTHX_ HEK *hek)
2299 unshare_hek_or_pvn(hek, NULL, 0, 0);
2302 /* possibly free a shared string if no one has access to it
2303 hek if non-NULL takes priority over the other 3, else str, len and hash
2304 are used. If so, len and hash must both be valid for str.
2307 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2310 register XPVHV* xhv;
2312 register HE **oentry;
2314 bool is_utf8 = FALSE;
2316 const char * const save = str;
2317 struct shared_he *he = NULL;
2320 /* Find the shared he which is just before us in memory. */
2321 he = (struct shared_he *)(((char *)hek)
2322 - STRUCT_OFFSET(struct shared_he,
2325 /* Assert that the caller passed us a genuine (or at least consistent)
2327 assert (he->shared_he_he.hent_hek == hek);
2330 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2331 --he->shared_he_he.he_valu.hent_refcount;
2332 UNLOCK_STRTAB_MUTEX;
2335 UNLOCK_STRTAB_MUTEX;
2337 hash = HEK_HASH(hek);
2338 } else if (len < 0) {
2339 STRLEN tmplen = -len;
2341 /* See the note in hv_fetch(). --jhi */
2342 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2345 k_flags = HVhek_UTF8;
2347 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2350 /* what follows was the moral equivalent of:
2351 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2353 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2355 xhv = (XPVHV*)SvANY(PL_strtab);
2356 /* assert(xhv_array != 0) */
2358 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2360 const HE *const he_he = &(he->shared_he_he);
2361 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2366 const int flags_masked = k_flags & HVhek_MASK;
2367 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2368 if (HeHASH(entry) != hash) /* strings can't be equal */
2370 if (HeKLEN(entry) != len)
2372 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2374 if (HeKFLAGS(entry) != flags_masked)
2381 if (--entry->he_valu.hent_refcount == 0) {
2382 *oentry = HeNEXT(entry);
2384 /* There are now no entries in our slot. */
2385 xhv->xhv_fill--; /* HvFILL(hv)-- */
2388 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2392 UNLOCK_STRTAB_MUTEX;
2393 if (!entry && ckWARN_d(WARN_INTERNAL))
2394 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2395 "Attempt to free non-existent shared string '%s'%s"
2397 hek ? HEK_KEY(hek) : str,
2398 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2399 if (k_flags & HVhek_FREEKEY)
2403 /* get a (constant) string ptr from the global string table
2404 * string will get added if it is not already there.
2405 * len and hash must both be valid for str.
2408 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2410 bool is_utf8 = FALSE;
2412 const char * const save = str;
2415 STRLEN tmplen = -len;
2417 /* See the note in hv_fetch(). --jhi */
2418 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2420 /* If we were able to downgrade here, then than means that we were passed
2421 in a key which only had chars 0-255, but was utf8 encoded. */
2424 /* If we found we were able to downgrade the string to bytes, then
2425 we should flag that it needs upgrading on keys or each. Also flag
2426 that we need share_hek_flags to free the string. */
2428 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2431 return share_hek_flags (str, len, hash, flags);
2435 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2439 const int flags_masked = flags & HVhek_MASK;
2440 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2442 /* what follows is the moral equivalent of:
2444 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2445 hv_store(PL_strtab, str, len, NULL, hash);
2447 Can't rehash the shared string table, so not sure if it's worth
2448 counting the number of entries in the linked list
2450 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2451 /* assert(xhv_array != 0) */
2453 entry = (HvARRAY(PL_strtab))[hindex];
2454 for (;entry; entry = HeNEXT(entry)) {
2455 if (HeHASH(entry) != hash) /* strings can't be equal */
2457 if (HeKLEN(entry) != len)
2459 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2461 if (HeKFLAGS(entry) != flags_masked)
2467 /* What used to be head of the list.
2468 If this is NULL, then we're the first entry for this slot, which
2469 means we need to increate fill. */
2470 struct shared_he *new_entry;
2473 HE **const head = &HvARRAY(PL_strtab)[hindex];
2474 HE *const next = *head;
2476 /* We don't actually store a HE from the arena and a regular HEK.
2477 Instead we allocate one chunk of memory big enough for both,
2478 and put the HEK straight after the HE. This way we can find the
2479 HEK directly from the HE.
2482 Newx(k, STRUCT_OFFSET(struct shared_he,
2483 shared_he_hek.hek_key[0]) + len + 2, char);
2484 new_entry = (struct shared_he *)k;
2485 entry = &(new_entry->shared_he_he);
2486 hek = &(new_entry->shared_he_hek);
2488 Copy(str, HEK_KEY(hek), len, char);
2489 HEK_KEY(hek)[len] = 0;
2491 HEK_HASH(hek) = hash;
2492 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2494 /* Still "point" to the HEK, so that other code need not know what
2496 HeKEY_hek(entry) = hek;
2497 entry->he_valu.hent_refcount = 0;
2498 HeNEXT(entry) = next;
2501 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2502 if (!next) { /* initial entry? */
2503 xhv->xhv_fill++; /* HvFILL(hv)++ */
2504 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2509 ++entry->he_valu.hent_refcount;
2510 UNLOCK_STRTAB_MUTEX;
2512 if (flags & HVhek_FREEKEY)
2515 return HeKEY_hek(entry);
2519 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2522 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2523 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2524 if (uf->uf_set == NULL) {
2525 SV* obj = mg->mg_obj;
2526 mg->mg_obj = keysv; /* pass key */
2527 uf->uf_index = action; /* pass action */
2528 magic_getuvar((SV*)hv, mg);
2529 keysv = mg->mg_obj; /* may have changed */
2537 Perl_hv_placeholders_p(pTHX_ HV *hv)
2540 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2543 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2546 Perl_die(aTHX_ "panic: hv_placeholders_p");
2549 return &(mg->mg_len);
2554 Perl_hv_placeholders_get(pTHX_ HV *hv)
2557 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2559 return mg ? mg->mg_len : 0;
2563 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2566 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2571 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2572 Perl_die(aTHX_ "panic: hv_placeholders_set");
2574 /* else we don't need to add magic to record 0 placeholders. */
2578 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2581 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2586 value = &PL_sv_placeholder;
2589 value = (he->refcounted_he_data[0] & HVrhek_UV)
2590 ? newSVuv(he->refcounted_he_val.refcounted_he_u_iv)
2591 : newSViv(he->refcounted_he_val.refcounted_he_u_uv);
2594 /* Create a string SV that directly points to the bytes in our
2597 sv_upgrade(value, SVt_PV);
2598 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2599 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2600 /* This stops anything trying to free it */
2601 SvLEN_set(value, 0);
2603 SvREADONLY_on(value);
2604 if (he->refcounted_he_data[0] & HVrhek_UTF8)
2608 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2609 he->refcounted_he_data[0]);
2615 /* A big expression to find the key offset */
2616 #define REF_HE_KEY(chain) \
2617 ((((chain->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV) \
2618 ? chain->refcounted_he_val.refcounted_he_u_len + 1 : 0) \
2619 + 1 + chain->refcounted_he_data)
2623 =for apidoc refcounted_he_chain_2hv
2625 Generates an returns a C<HV *> by walking up the tree starting at the passed
2626 in C<struct refcounted_he *>.
2631 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2635 U32 placeholders = 0;
2636 /* We could chase the chain once to get an idea of the number of keys,
2637 and call ksplit. But for now we'll make a potentially inefficient
2638 hash with only 8 entries in its array. */
2639 const U32 max = HvMAX(hv);
2643 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2644 HvARRAY(hv) = (HE**)array;
2649 U32 hash = chain->refcounted_he_hash;
2651 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2653 HE **oentry = &((HvARRAY(hv))[hash & max]);
2654 HE *entry = *oentry;
2657 for (; entry; entry = HeNEXT(entry)) {
2658 if (HeHASH(entry) == hash) {
2659 /* We might have a duplicate key here. If so, entry is older
2660 than the key we've already put in the hash, so if they are
2661 the same, skip adding entry. */
2663 const STRLEN klen = HeKLEN(entry);
2664 const char *const key = HeKEY(entry);
2665 if (klen == chain->refcounted_he_keylen
2666 && (!!HeKUTF8(entry)
2667 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2668 && memEQ(key, REF_HE_KEY(chain), klen))
2671 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2673 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2674 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2675 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2686 = share_hek_flags(REF_HE_KEY(chain),
2687 chain->refcounted_he_keylen,
2688 chain->refcounted_he_hash,
2689 (chain->refcounted_he_data[0]
2690 & (HVhek_UTF8|HVhek_WASUTF8)));
2692 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2694 value = refcounted_he_value(chain);
2695 if (value == &PL_sv_placeholder)
2697 HeVAL(entry) = value;
2699 /* Link it into the chain. */
2700 HeNEXT(entry) = *oentry;
2701 if (!HeNEXT(entry)) {
2702 /* initial entry. */
2710 chain = chain->refcounted_he_next;
2714 clear_placeholders(hv, placeholders);
2715 HvTOTALKEYS(hv) -= placeholders;
2718 /* We could check in the loop to see if we encounter any keys with key
2719 flags, but it's probably not worth it, as this per-hash flag is only
2720 really meant as an optimisation for things like Storable. */
2722 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2728 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2729 const char *key, STRLEN klen, int flags, U32 hash)
2731 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2732 of your key has to exactly match that which is stored. */
2733 SV *value = &PL_sv_placeholder;
2737 if (flags & HVhek_FREEKEY)
2739 key = SvPV_const(keysv, klen);
2741 is_utf8 = (SvUTF8(keysv) != 0);
2743 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2747 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2748 hash = SvSHARED_HASH(keysv);
2750 PERL_HASH(hash, key, klen);
2754 for (; chain; chain = chain->refcounted_he_next) {
2756 if (hash != chain->refcounted_he_hash)
2758 if (klen != chain->refcounted_he_keylen)
2760 if (memNE(REF_HE_KEY(chain),key,klen))
2762 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2765 if (hash != HEK_HASH(chain->refcounted_he_hek))
2767 if (klen != HEK_LEN(chain->refcounted_he_hek))
2769 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2771 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2775 value = sv_2mortal(refcounted_he_value(chain));
2779 if (flags & HVhek_FREEKEY)
2786 =for apidoc refcounted_he_new
2788 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2789 stored in a compact form, all references remain the property of the caller.
2790 The C<struct refcounted_he> is returned with a reference count of 1.
2795 struct refcounted_he *
2796 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2797 SV *const key, SV *const value) {
2799 struct refcounted_he *he;
2801 const char *key_p = SvPV_const(key, key_len);
2802 STRLEN value_len = 0;
2803 const char *value_p = NULL;
2808 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2811 value_type = HVrhek_PV;
2812 } else if (SvIOK(value)) {
2813 value_type = HVrhek_IV;
2814 } else if (value == &PL_sv_placeholder) {
2815 value_type = HVrhek_delete;
2816 } else if (!SvOK(value)) {
2817 value_type = HVrhek_undef;
2819 value_type = HVrhek_PV;
2822 if (value_type == HVrhek_PV) {
2823 value_p = SvPV_const(value, value_len);
2824 key_offset = value_len + 2;
2832 he = PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2836 he = PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2841 he->refcounted_he_next = parent;
2843 if (value_type == HVrhek_PV) {
2844 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2845 he->refcounted_he_val.refcounted_he_u_len = value_len;
2846 if (SvUTF8(value)) {
2847 flags |= HVrhek_UTF8;
2849 } else if (value_type == HVrhek_IV) {
2851 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2854 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2859 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2860 As we're going to be building hash keys from this value in future,
2861 normalise it now. */
2862 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2863 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2865 PERL_HASH(hash, key_p, key_len);
2868 he->refcounted_he_hash = hash;
2869 he->refcounted_he_keylen = key_len;
2870 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2872 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2875 if (flags & HVhek_WASUTF8) {
2876 /* If it was downgraded from UTF-8, then the pointer returned from
2877 bytes_from_utf8 is an allocated pointer that we must free. */
2881 he->refcounted_he_data[0] = flags;
2882 he->refcounted_he_refcnt = 1;
2888 =for apidoc refcounted_he_free
2890 Decrements the reference count of the passed in C<struct refcounted_he *>
2891 by one. If the reference count reaches zero the structure's memory is freed,
2892 and C<refcounted_he_free> iterates onto the parent node.
2898 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2899 PERL_UNUSED_CONTEXT;
2902 struct refcounted_he *copy;
2906 new_count = --he->refcounted_he_refcnt;
2907 HINTS_REFCNT_UNLOCK;
2913 #ifndef USE_ITHREADS
2914 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2917 he = he->refcounted_he_next;
2918 PerlMemShared_free(copy);
2923 =for apidoc hv_assert
2925 Check that a hash is in an internally consistent state.
2933 Perl_hv_assert(pTHX_ HV *hv)
2938 int placeholders = 0;
2941 const I32 riter = HvRITER_get(hv);
2942 HE *eiter = HvEITER_get(hv);
2944 (void)hv_iterinit(hv);
2946 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2947 /* sanity check the values */
2948 if (HeVAL(entry) == &PL_sv_placeholder)
2952 /* sanity check the keys */
2953 if (HeSVKEY(entry)) {
2954 NOOP; /* Don't know what to check on SV keys. */
2955 } else if (HeKUTF8(entry)) {
2957 if (HeKWASUTF8(entry)) {
2958 PerlIO_printf(Perl_debug_log,
2959 "hash key has both WASUFT8 and UTF8: '%.*s'\n",
2960 (int) HeKLEN(entry), HeKEY(entry));
2963 } else if (HeKWASUTF8(entry))
2966 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2967 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2968 const int nhashkeys = HvUSEDKEYS(hv);
2969 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2971 if (nhashkeys != real) {
2972 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2975 if (nhashplaceholders != placeholders) {
2976 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2980 if (withflags && ! HvHASKFLAGS(hv)) {
2981 PerlIO_printf(Perl_debug_log,
2982 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2989 HvRITER_set(hv, riter); /* Restore hash iterator state */
2990 HvEITER_set(hv, eiter);
2997 * c-indentation-style: bsd
2999 * indent-tabs-mode: t
3002 * ex: set ts=8 sts=4 sw=4 noet: