3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 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";
43 HE* he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
44 HE * const heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
46 PL_body_roots[HE_SVSLOT] = he;
48 HeNEXT(he) = (HE*)(he + 1);
56 #define new_HE() (HE*)safemalloc(sizeof(HE))
57 #define del_HE(p) safefree((char*)p)
66 void ** const root = &PL_body_roots[HE_SVSLOT];
76 #define new_HE() new_he()
79 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
80 PL_body_roots[HE_SVSLOT] = p; \
88 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
90 const int flags_masked = flags & HVhek_MASK;
94 Newx(k, HEK_BASESIZE + len + 2, char);
96 Copy(str, HEK_KEY(hek), len, char);
97 HEK_KEY(hek)[len] = 0;
100 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
102 if (flags & HVhek_FREEKEY)
107 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
111 Perl_free_tied_hv_pool(pTHX)
114 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
121 PL_hv_fetch_ent_mh = NULL;
124 #if defined(USE_ITHREADS)
126 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
128 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 PERL_UNUSED_ARG(param);
133 /* We already shared this hash key. */
134 (void)share_hek_hek(shared);
138 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
139 HEK_HASH(source), HEK_FLAGS(source));
140 ptr_table_store(PL_ptr_table, source, shared);
146 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
152 /* look for it in the table first */
153 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
157 /* create anew and remember what it is */
159 ptr_table_store(PL_ptr_table, e, ret);
161 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
162 if (HeKLEN(e) == HEf_SVKEY) {
164 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
165 HeKEY_hek(ret) = (HEK*)k;
166 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
169 /* This is hek_dup inlined, which seems to be important for speed
171 HEK * const source = HeKEY_hek(e);
172 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
175 /* We already shared this hash key. */
176 (void)share_hek_hek(shared);
180 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
181 HEK_HASH(source), HEK_FLAGS(source));
182 ptr_table_store(PL_ptr_table, source, shared);
184 HeKEY_hek(ret) = shared;
187 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
189 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
192 #endif /* USE_ITHREADS */
195 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
198 SV * const sv = sv_newmortal();
199 if (!(flags & HVhek_FREEKEY)) {
200 sv_setpvn(sv, key, klen);
203 /* Need to free saved eventually assign to mortal SV */
204 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
205 sv_usepvn(sv, (char *) key, klen);
207 if (flags & HVhek_UTF8) {
210 Perl_croak(aTHX_ msg, SVfARG(sv));
213 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
219 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
220 the length of the key. The C<hash> parameter is the precomputed hash
221 value; if it is zero then Perl will compute it. The return value will be
222 NULL if the operation failed or if the value did not need to be actually
223 stored within the hash (as in the case of tied hashes). Otherwise it can
224 be dereferenced to get the original C<SV*>. Note that the caller is
225 responsible for suitably incrementing the reference count of C<val> before
226 the call, and decrementing it if the function returned NULL. Effectively
227 a successful hv_store takes ownership of one reference to C<val>. This is
228 usually what you want; a newly created SV has a reference count of one, so
229 if all your code does is create SVs then store them in a hash, hv_store
230 will own the only reference to the new SV, and your code doesn't need to do
231 anything further to tidy up. hv_store is not implemented as a call to
232 hv_store_ent, and does not create a temporary SV for the key, so if your
233 key data is not already in SV form then use hv_store in preference to
236 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
237 information on how to use this function on tied hashes.
243 Perl_hv_store(pTHX_ HV *hv, const char *key, I32 klen_i32, SV *val, U32 hash)
256 hek = hv_fetch_common (hv, NULL, key, klen, flags,
257 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
258 return hek ? &HeVAL(hek) : NULL;
261 /* XXX This looks like an ideal candidate to inline */
263 Perl_hv_store_flags(pTHX_ HV *hv, const char *key, I32 klen, SV *val,
264 register U32 hash, int flags)
266 HE * const hek = hv_fetch_common (hv, NULL, key, klen, flags,
267 (HV_FETCH_ISSTORE|HV_FETCH_JUST_SV), val, hash);
268 return hek ? &HeVAL(hek) : NULL;
272 =for apidoc hv_store_ent
274 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
275 parameter is the precomputed hash value; if it is zero then Perl will
276 compute it. The return value is the new hash entry so created. It will be
277 NULL if the operation failed or if the value did not need to be actually
278 stored within the hash (as in the case of tied hashes). Otherwise the
279 contents of the return value can be accessed using the C<He?> macros
280 described here. Note that the caller is responsible for suitably
281 incrementing the reference count of C<val> before the call, and
282 decrementing it if the function returned NULL. Effectively a successful
283 hv_store_ent takes ownership of one reference to C<val>. This is
284 usually what you want; a newly created SV has a reference count of one, so
285 if all your code does is create SVs then store them in a hash, hv_store
286 will own the only reference to the new SV, and your code doesn't need to do
287 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
288 unlike C<val> it does not take ownership of it, so maintaining the correct
289 reference count on C<key> is entirely the caller's responsibility. hv_store
290 is not implemented as a call to hv_store_ent, and does not create a temporary
291 SV for the key, so if your key data is not already in SV form then use
292 hv_store in preference to hv_store_ent.
294 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
295 information on how to use this function on tied hashes.
300 /* XXX This looks like an ideal candidate to inline */
302 Perl_hv_store_ent(pTHX_ HV *hv, SV *keysv, SV *val, U32 hash)
304 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISSTORE, val, hash);
308 =for apidoc hv_exists
310 Returns a boolean indicating whether the specified hash key exists. The
311 C<klen> is the length of the key.
317 Perl_hv_exists(pTHX_ HV *hv, const char *key, I32 klen_i32)
329 return hv_fetch_common(hv, NULL, key, klen, flags, HV_FETCH_ISEXISTS, 0, 0)
336 Returns the SV which corresponds to the specified key in the hash. The
337 C<klen> is the length of the key. If C<lval> is set then the fetch will be
338 part of a store. Check that the return value is non-null before
339 dereferencing it to an C<SV*>.
341 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
342 information on how to use this function on tied hashes.
348 Perl_hv_fetch(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 lval)
361 hek = hv_fetch_common (hv, NULL, key, klen, flags,
362 lval ? (HV_FETCH_JUST_SV | HV_FETCH_LVALUE) : HV_FETCH_JUST_SV,
364 return hek ? &HeVAL(hek) : NULL;
368 =for apidoc hv_exists_ent
370 Returns a boolean indicating whether the specified hash key exists. C<hash>
371 can be a valid precomputed hash value, or 0 to ask for it to be
377 /* XXX This looks like an ideal candidate to inline */
379 Perl_hv_exists_ent(pTHX_ HV *hv, SV *keysv, U32 hash)
381 return hv_fetch_common(hv, keysv, NULL, 0, 0, HV_FETCH_ISEXISTS, 0, hash)
385 /* returns an HE * structure with the all fields set */
386 /* note that hent_val will be a mortal sv for MAGICAL hashes */
388 =for apidoc hv_fetch_ent
390 Returns the hash entry which corresponds to the specified key in the hash.
391 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
392 if you want the function to compute it. IF C<lval> is set then the fetch
393 will be part of a store. Make sure the return value is non-null before
394 accessing it. The return value when C<tb> is a tied hash is a pointer to a
395 static location, so be sure to make a copy of the structure if you need to
398 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
399 information on how to use this function on tied hashes.
405 Perl_hv_fetch_ent(pTHX_ HV *hv, SV *keysv, I32 lval, register U32 hash)
407 return hv_fetch_common(hv, keysv, NULL, 0, 0,
408 (lval ? HV_FETCH_LVALUE : 0), NULL, hash);
412 S_hv_fetch_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
413 int flags, int action, SV *val, register U32 hash)
426 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
427 keysv = hv_magic_uvar_xkey(hv, keysv, key, klen, flags, action);
428 /* If a fetch-as-store fails on the fetch, then the action is to
429 recurse once into "hv_store". If we didn't do this, then that
430 recursive call would call the key conversion routine again.
431 However, as we replace the original key with the converted
432 key, this would result in a double conversion, which would show
433 up as a bug if the conversion routine is not idempotent. */
436 if (flags & HVhek_FREEKEY)
438 key = SvPV_const(keysv, klen);
440 is_utf8 = (SvUTF8(keysv) != 0);
442 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
445 xhv = (XPVHV*)SvANY(hv);
447 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
448 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
450 /* XXX should be able to skimp on the HE/HEK here when
451 HV_FETCH_JUST_SV is true. */
453 keysv = newSVpvn(key, klen);
458 keysv = newSVsv(keysv);
461 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
463 /* grab a fake HE/HEK pair from the pool or make a new one */
464 entry = PL_hv_fetch_ent_mh;
466 PL_hv_fetch_ent_mh = HeNEXT(entry);
470 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
471 HeKEY_hek(entry) = (HEK*)k;
473 HeNEXT(entry) = NULL;
474 HeSVKEY_set(entry, keysv);
476 sv_upgrade(sv, SVt_PVLV);
478 /* so we can free entry when freeing sv */
479 LvTARG(sv) = (SV*)entry;
481 /* XXX remove at some point? */
482 if (flags & HVhek_FREEKEY)
487 #ifdef ENV_IS_CASELESS
488 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
490 for (i = 0; i < klen; ++i)
491 if (isLOWER(key[i])) {
492 /* Would be nice if we had a routine to do the
493 copy and upercase in a single pass through. */
494 const char * const nkey = strupr(savepvn(key,klen));
495 /* Note that this fetch is for nkey (the uppercased
496 key) whereas the store is for key (the original) */
497 entry = hv_fetch_common(hv, NULL, nkey, klen,
498 HVhek_FREEKEY, /* free nkey */
499 0 /* non-LVAL fetch */
500 | HV_DISABLE_UVAR_XKEY,
502 0 /* compute hash */);
503 if (!entry && (action & HV_FETCH_LVALUE)) {
504 /* This call will free key if necessary.
505 Do it this way to encourage compiler to tail
507 entry = hv_fetch_common(hv, keysv, key, klen,
510 | HV_DISABLE_UVAR_XKEY,
513 if (flags & HVhek_FREEKEY)
521 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
522 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
523 /* I don't understand why hv_exists_ent has svret and sv,
524 whereas hv_exists only had one. */
525 SV * const svret = sv_newmortal();
528 if (keysv || is_utf8) {
530 keysv = newSVpvn(key, klen);
533 keysv = newSVsv(keysv);
535 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
537 mg_copy((SV*)hv, sv, key, klen);
539 if (flags & HVhek_FREEKEY)
541 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
542 /* This cast somewhat evil, but I'm merely using NULL/
543 not NULL to return the boolean exists.
544 And I know hv is not NULL. */
545 return SvTRUE(svret) ? (HE *)hv : NULL;
547 #ifdef ENV_IS_CASELESS
548 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
549 /* XXX This code isn't UTF8 clean. */
550 char * const keysave = (char * const)key;
551 /* Will need to free this, so set FREEKEY flag. */
552 key = savepvn(key,klen);
553 key = (const char*)strupr((char*)key);
558 if (flags & HVhek_FREEKEY) {
561 flags |= HVhek_FREEKEY;
565 else if (action & HV_FETCH_ISSTORE) {
568 hv_magic_check (hv, &needs_copy, &needs_store);
570 const bool save_taint = PL_tainted;
571 if (keysv || is_utf8) {
573 keysv = newSVpvn(key, klen);
577 PL_tainted = SvTAINTED(keysv);
578 keysv = sv_2mortal(newSVsv(keysv));
579 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
581 mg_copy((SV*)hv, val, key, klen);
584 TAINT_IF(save_taint);
586 if (flags & HVhek_FREEKEY)
590 #ifdef ENV_IS_CASELESS
591 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
592 /* XXX This code isn't UTF8 clean. */
593 const char *keysave = key;
594 /* Will need to free this, so set FREEKEY flag. */
595 key = savepvn(key,klen);
596 key = (const char*)strupr((char*)key);
601 if (flags & HVhek_FREEKEY) {
604 flags |= HVhek_FREEKEY;
612 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
613 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
614 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
619 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
621 HvARRAY(hv) = (HE**)array;
623 #ifdef DYNAMIC_ENV_FETCH
624 else if (action & HV_FETCH_ISEXISTS) {
625 /* for an %ENV exists, if we do an insert it's by a recursive
626 store call, so avoid creating HvARRAY(hv) right now. */
630 /* XXX remove at some point? */
631 if (flags & HVhek_FREEKEY)
639 char * const keysave = (char *)key;
640 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
644 flags &= ~HVhek_UTF8;
645 if (key != keysave) {
646 if (flags & HVhek_FREEKEY)
648 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
653 PERL_HASH_INTERNAL(hash, key, klen);
654 /* We don't have a pointer to the hv, so we have to replicate the
655 flag into every HEK, so that hv_iterkeysv can see it. */
656 /* And yes, you do need this even though you are not "storing" because
657 you can flip the flags below if doing an lval lookup. (And that
658 was put in to give the semantics Andreas was expecting.) */
659 flags |= HVhek_REHASH;
661 if (keysv && (SvIsCOW_shared_hash(keysv))) {
662 hash = SvSHARED_HASH(keysv);
664 PERL_HASH(hash, key, klen);
668 masked_flags = (flags & HVhek_MASK);
670 #ifdef DYNAMIC_ENV_FETCH
671 if (!HvARRAY(hv)) entry = NULL;
675 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
677 for (; entry; entry = HeNEXT(entry)) {
678 if (HeHASH(entry) != hash) /* strings can't be equal */
680 if (HeKLEN(entry) != (I32)klen)
682 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
684 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
687 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
688 if (HeKFLAGS(entry) != masked_flags) {
689 /* We match if HVhek_UTF8 bit in our flags and hash key's
690 match. But if entry was set previously with HVhek_WASUTF8
691 and key now doesn't (or vice versa) then we should change
692 the key's flag, as this is assignment. */
693 if (HvSHAREKEYS(hv)) {
694 /* Need to swap the key we have for a key with the flags we
695 need. As keys are shared we can't just write to the
696 flag, so we share the new one, unshare the old one. */
697 HEK * const new_hek = share_hek_flags(key, klen, hash,
699 unshare_hek (HeKEY_hek(entry));
700 HeKEY_hek(entry) = new_hek;
702 else if (hv == PL_strtab) {
703 /* PL_strtab is usually the only hash without HvSHAREKEYS,
704 so putting this test here is cheap */
705 if (flags & HVhek_FREEKEY)
707 Perl_croak(aTHX_ S_strtab_error,
708 action & HV_FETCH_LVALUE ? "fetch" : "store");
711 HeKFLAGS(entry) = masked_flags;
712 if (masked_flags & HVhek_ENABLEHVKFLAGS)
715 if (HeVAL(entry) == &PL_sv_placeholder) {
716 /* yes, can store into placeholder slot */
717 if (action & HV_FETCH_LVALUE) {
719 /* This preserves behaviour with the old hv_fetch
720 implementation which at this point would bail out
721 with a break; (at "if we find a placeholder, we
722 pretend we haven't found anything")
724 That break mean that if a placeholder were found, it
725 caused a call into hv_store, which in turn would
726 check magic, and if there is no magic end up pretty
727 much back at this point (in hv_store's code). */
730 /* LVAL fetch which actaully needs a store. */
732 HvPLACEHOLDERS(hv)--;
735 if (val != &PL_sv_placeholder)
736 HvPLACEHOLDERS(hv)--;
739 } else if (action & HV_FETCH_ISSTORE) {
740 SvREFCNT_dec(HeVAL(entry));
743 } else if (HeVAL(entry) == &PL_sv_placeholder) {
744 /* if we find a placeholder, we pretend we haven't found
748 if (flags & HVhek_FREEKEY)
752 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
753 if (!(action & HV_FETCH_ISSTORE)
754 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
756 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
758 sv = newSVpvn(env,len);
760 return hv_fetch_common(hv, keysv, key, klen, flags,
761 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, sv,
767 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
768 hv_notallowed(flags, key, klen,
769 "Attempt to access disallowed key '%"SVf"' in"
770 " a restricted hash");
772 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
773 /* Not doing some form of store, so return failure. */
774 if (flags & HVhek_FREEKEY)
778 if (action & HV_FETCH_LVALUE) {
781 /* At this point the old hv_fetch code would call to hv_store,
782 which in turn might do some tied magic. So we need to make that
783 magic check happen. */
784 /* gonna assign to this, so it better be there */
785 return hv_fetch_common(hv, keysv, key, klen, flags,
786 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY, val,
788 /* XXX Surely that could leak if the fetch-was-store fails?
789 Just like the hv_fetch. */
793 /* Welcome to hv_store... */
796 /* Not sure if we can get here. I think the only case of oentry being
797 NULL is for %ENV with dynamic env fetch. But that should disappear
798 with magic in the previous code. */
801 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
803 HvARRAY(hv) = (HE**)array;
806 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
809 /* share_hek_flags will do the free for us. This might be considered
812 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
813 else if (hv == PL_strtab) {
814 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
815 this test here is cheap */
816 if (flags & HVhek_FREEKEY)
818 Perl_croak(aTHX_ S_strtab_error,
819 action & HV_FETCH_LVALUE ? "fetch" : "store");
821 else /* gotta do the real thing */
822 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
824 HeNEXT(entry) = *oentry;
827 if (val == &PL_sv_placeholder)
828 HvPLACEHOLDERS(hv)++;
829 if (masked_flags & HVhek_ENABLEHVKFLAGS)
833 const HE *counter = HeNEXT(entry);
835 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
836 if (!counter) { /* initial entry? */
837 xhv->xhv_fill++; /* HvFILL(hv)++ */
838 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
840 } else if(!HvREHASH(hv)) {
843 while ((counter = HeNEXT(counter)))
846 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
847 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
848 bucket splits on a rehashed hash, as we're not going to
849 split it again, and if someone is lucky (evil) enough to
850 get all the keys in one list they could exhaust our memory
851 as we repeatedly double the number of buckets on every
852 entry. Linear search feels a less worse thing to do. */
862 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
864 const MAGIC *mg = SvMAGIC(hv);
868 if (isUPPER(mg->mg_type)) {
870 if (mg->mg_type == PERL_MAGIC_tied) {
871 *needs_store = FALSE;
872 return; /* We've set all there is to set. */
875 mg = mg->mg_moremagic;
880 =for apidoc hv_scalar
882 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
888 Perl_hv_scalar(pTHX_ HV *hv)
892 if (SvRMAGICAL(hv)) {
893 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
895 return magic_scalarpack(hv, mg);
900 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
901 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
909 =for apidoc hv_delete
911 Deletes a key/value pair in the hash. The value SV is removed from the
912 hash and returned to the caller. The C<klen> is the length of the key.
913 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
920 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
927 k_flags = HVhek_UTF8;
932 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
936 =for apidoc hv_delete_ent
938 Deletes a key/value pair in the hash. The value SV is removed from the
939 hash and returned to the caller. The C<flags> value will normally be zero;
940 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
941 precomputed hash value, or 0 to ask for it to be computed.
946 /* XXX This looks like an ideal candidate to inline */
948 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
950 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
954 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
955 int k_flags, I32 d_flags, U32 hash)
960 register HE **oentry;
961 HE *const *first_entry;
968 if (SvSMAGICAL(hv) && SvGMAGICAL(hv)
969 && !(d_flags & HV_DISABLE_UVAR_XKEY))
970 keysv = hv_magic_uvar_xkey(hv, keysv, key, klen, k_flags, HV_DELETE);
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,
990 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
992 sv = entry ? HeVAL(entry) : NULL;
998 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
999 /* No longer an element */
1000 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1003 return NULL; /* element cannot be deleted */
1005 #ifdef ENV_IS_CASELESS
1006 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
1007 /* XXX This code isn't UTF8 clean. */
1008 keysv = sv_2mortal(newSVpvn(key,klen));
1009 if (k_flags & HVhek_FREEKEY) {
1012 key = strupr(SvPVX(keysv));
1021 xhv = (XPVHV*)SvANY(hv);
1026 const char * const keysave = key;
1027 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1030 k_flags |= HVhek_UTF8;
1032 k_flags &= ~HVhek_UTF8;
1033 if (key != keysave) {
1034 if (k_flags & HVhek_FREEKEY) {
1035 /* This shouldn't happen if our caller does what we expect,
1036 but strictly the API allows it. */
1039 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1041 HvHASKFLAGS_on((SV*)hv);
1045 PERL_HASH_INTERNAL(hash, key, klen);
1047 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1048 hash = SvSHARED_HASH(keysv);
1050 PERL_HASH(hash, key, klen);
1054 masked_flags = (k_flags & HVhek_MASK);
1056 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1058 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1060 if (HeHASH(entry) != hash) /* strings can't be equal */
1062 if (HeKLEN(entry) != (I32)klen)
1064 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1066 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1069 if (hv == PL_strtab) {
1070 if (k_flags & HVhek_FREEKEY)
1072 Perl_croak(aTHX_ S_strtab_error, "delete");
1075 /* if placeholder is here, it's already been deleted.... */
1076 if (HeVAL(entry) == &PL_sv_placeholder) {
1077 if (k_flags & HVhek_FREEKEY)
1081 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1082 hv_notallowed(k_flags, key, klen,
1083 "Attempt to delete readonly key '%"SVf"' from"
1084 " a restricted hash");
1086 if (k_flags & HVhek_FREEKEY)
1089 if (d_flags & G_DISCARD)
1092 sv = sv_2mortal(HeVAL(entry));
1093 HeVAL(entry) = &PL_sv_placeholder;
1097 * If a restricted hash, rather than really deleting the entry, put
1098 * a placeholder there. This marks the key as being "approved", so
1099 * we can still access via not-really-existing key without raising
1102 if (SvREADONLY(hv)) {
1103 SvREFCNT_dec(HeVAL(entry));
1104 HeVAL(entry) = &PL_sv_placeholder;
1105 /* We'll be saving this slot, so the number of allocated keys
1106 * doesn't go down, but the number placeholders goes up */
1107 HvPLACEHOLDERS(hv)++;
1109 *oentry = HeNEXT(entry);
1111 xhv->xhv_fill--; /* HvFILL(hv)-- */
1113 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1116 hv_free_ent(hv, entry);
1117 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1118 if (xhv->xhv_keys == 0)
1119 HvHASKFLAGS_off(hv);
1123 if (SvREADONLY(hv)) {
1124 hv_notallowed(k_flags, key, klen,
1125 "Attempt to delete disallowed key '%"SVf"' from"
1126 " a restricted hash");
1129 if (k_flags & HVhek_FREEKEY)
1135 S_hsplit(pTHX_ HV *hv)
1138 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1139 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1140 register I32 newsize = oldsize * 2;
1142 char *a = (char*) HvARRAY(hv);
1144 register HE **oentry;
1145 int longest_chain = 0;
1148 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1149 (void*)hv, (int) oldsize);*/
1151 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1152 /* Can make this clear any placeholders first for non-restricted hashes,
1153 even though Storable rebuilds restricted hashes by putting in all the
1154 placeholders (first) before turning on the readonly flag, because
1155 Storable always pre-splits the hash. */
1156 hv_clear_placeholders(hv);
1160 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1161 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1162 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1168 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1171 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1172 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1177 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1179 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1181 if (oldsize >= 64) {
1182 offer_nice_chunk(HvARRAY(hv),
1183 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1184 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1187 Safefree(HvARRAY(hv));
1191 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1192 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1193 HvARRAY(hv) = (HE**) a;
1196 for (i=0; i<oldsize; i++,aep++) {
1197 int left_length = 0;
1198 int right_length = 0;
1202 if (!*aep) /* non-existent */
1205 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1206 if ((HeHASH(entry) & newsize) != (U32)i) {
1207 *oentry = HeNEXT(entry);
1208 HeNEXT(entry) = *bep;
1210 xhv->xhv_fill++; /* HvFILL(hv)++ */
1216 oentry = &HeNEXT(entry);
1220 if (!*aep) /* everything moved */
1221 xhv->xhv_fill--; /* HvFILL(hv)-- */
1222 /* I think we don't actually need to keep track of the longest length,
1223 merely flag if anything is too long. But for the moment while
1224 developing this code I'll track it. */
1225 if (left_length > longest_chain)
1226 longest_chain = left_length;
1227 if (right_length > longest_chain)
1228 longest_chain = right_length;
1232 /* Pick your policy for "hashing isn't working" here: */
1233 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1238 if (hv == PL_strtab) {
1239 /* Urg. Someone is doing something nasty to the string table.
1244 /* Awooga. Awooga. Pathological data. */
1245 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1246 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1249 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1250 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1252 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1255 was_shared = HvSHAREKEYS(hv);
1258 HvSHAREKEYS_off(hv);
1263 for (i=0; i<newsize; i++,aep++) {
1264 register HE *entry = *aep;
1266 /* We're going to trash this HE's next pointer when we chain it
1267 into the new hash below, so store where we go next. */
1268 HE * const next = HeNEXT(entry);
1273 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1278 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1279 hash, HeKFLAGS(entry));
1280 unshare_hek (HeKEY_hek(entry));
1281 HeKEY_hek(entry) = new_hek;
1283 /* Not shared, so simply write the new hash in. */
1284 HeHASH(entry) = hash;
1286 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1287 HEK_REHASH_on(HeKEY_hek(entry));
1288 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1290 /* Copy oentry to the correct new chain. */
1291 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1293 xhv->xhv_fill++; /* HvFILL(hv)++ */
1294 HeNEXT(entry) = *bep;
1300 Safefree (HvARRAY(hv));
1301 HvARRAY(hv) = (HE **)a;
1305 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1308 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1309 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1310 register I32 newsize;
1315 register HE **oentry;
1317 newsize = (I32) newmax; /* possible truncation here */
1318 if (newsize != newmax || newmax <= oldsize)
1320 while ((newsize & (1 + ~newsize)) != newsize) {
1321 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1323 if (newsize < newmax)
1325 if (newsize < newmax)
1326 return; /* overflow detection */
1328 a = (char *) HvARRAY(hv);
1331 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1332 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1333 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1339 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1342 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1343 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1348 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1350 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1352 if (oldsize >= 64) {
1353 offer_nice_chunk(HvARRAY(hv),
1354 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1355 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1358 Safefree(HvARRAY(hv));
1361 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1364 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1366 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1367 HvARRAY(hv) = (HE **) a;
1368 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1372 for (i=0; i<oldsize; i++,aep++) {
1373 if (!*aep) /* non-existent */
1375 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1376 register I32 j = (HeHASH(entry) & newsize);
1380 *oentry = HeNEXT(entry);
1381 if (!(HeNEXT(entry) = aep[j]))
1382 xhv->xhv_fill++; /* HvFILL(hv)++ */
1387 oentry = &HeNEXT(entry);
1389 if (!*aep) /* everything moved */
1390 xhv->xhv_fill--; /* HvFILL(hv)-- */
1397 Creates a new HV. The reference count is set to 1.
1405 register XPVHV* xhv;
1406 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1407 xhv = (XPVHV*)SvANY(hv);
1409 #ifndef NODEFAULT_SHAREKEYS
1410 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1413 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1414 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1419 Perl_newHVhv(pTHX_ HV *ohv)
1421 HV * const hv = newHV();
1422 STRLEN hv_max, hv_fill;
1424 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1426 hv_max = HvMAX(ohv);
1428 if (!SvMAGICAL((SV *)ohv)) {
1429 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1431 const bool shared = !!HvSHAREKEYS(ohv);
1432 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1434 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1437 /* In each bucket... */
1438 for (i = 0; i <= hv_max; i++) {
1440 HE *oent = oents[i];
1447 /* Copy the linked list of entries. */
1448 for (; oent; oent = HeNEXT(oent)) {
1449 const U32 hash = HeHASH(oent);
1450 const char * const key = HeKEY(oent);
1451 const STRLEN len = HeKLEN(oent);
1452 const int flags = HeKFLAGS(oent);
1453 HE * const ent = new_HE();
1455 HeVAL(ent) = newSVsv(HeVAL(oent));
1457 = shared ? share_hek_flags(key, len, hash, flags)
1458 : save_hek_flags(key, len, hash, flags);
1469 HvFILL(hv) = hv_fill;
1470 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1474 /* Iterate over ohv, copying keys and values one at a time. */
1476 const I32 riter = HvRITER_get(ohv);
1477 HE * const eiter = HvEITER_get(ohv);
1479 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1480 while (hv_max && hv_max + 1 >= hv_fill * 2)
1481 hv_max = hv_max / 2;
1485 while ((entry = hv_iternext_flags(ohv, 0))) {
1486 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1487 newSVsv(HeVAL(entry)), HeHASH(entry),
1490 HvRITER_set(ohv, riter);
1491 HvEITER_set(ohv, eiter);
1497 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1498 magic stays on it. */
1500 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1502 HV * const hv = newHV();
1505 if (ohv && (hv_fill = HvFILL(ohv))) {
1506 STRLEN hv_max = HvMAX(ohv);
1508 const I32 riter = HvRITER_get(ohv);
1509 HE * const eiter = HvEITER_get(ohv);
1511 while (hv_max && hv_max + 1 >= hv_fill * 2)
1512 hv_max = hv_max / 2;
1516 while ((entry = hv_iternext_flags(ohv, 0))) {
1517 SV *const sv = newSVsv(HeVAL(entry));
1518 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1519 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1520 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1521 sv, HeHASH(entry), HeKFLAGS(entry));
1523 HvRITER_set(ohv, riter);
1524 HvEITER_set(ohv, eiter);
1526 hv_magic(hv, NULL, PERL_MAGIC_hints);
1531 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1539 if (val && isGV(val) && GvCVu(val) && HvNAME_get(hv))
1540 mro_method_changed_in(hv); /* deletion of method from stash */
1542 if (HeKLEN(entry) == HEf_SVKEY) {
1543 SvREFCNT_dec(HeKEY_sv(entry));
1544 Safefree(HeKEY_hek(entry));
1546 else if (HvSHAREKEYS(hv))
1547 unshare_hek(HeKEY_hek(entry));
1549 Safefree(HeKEY_hek(entry));
1554 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1559 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1560 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1561 if (HeKLEN(entry) == HEf_SVKEY) {
1562 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1564 hv_free_ent(hv, entry);
1568 =for apidoc hv_clear
1570 Clears a hash, making it empty.
1576 Perl_hv_clear(pTHX_ HV *hv)
1579 register XPVHV* xhv;
1583 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1585 xhv = (XPVHV*)SvANY(hv);
1587 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1588 /* restricted hash: convert all keys to placeholders */
1590 for (i = 0; i <= xhv->xhv_max; i++) {
1591 HE *entry = (HvARRAY(hv))[i];
1592 for (; entry; entry = HeNEXT(entry)) {
1593 /* not already placeholder */
1594 if (HeVAL(entry) != &PL_sv_placeholder) {
1595 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1596 SV* const keysv = hv_iterkeysv(entry);
1598 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1601 SvREFCNT_dec(HeVAL(entry));
1602 HeVAL(entry) = &PL_sv_placeholder;
1603 HvPLACEHOLDERS(hv)++;
1611 HvPLACEHOLDERS_set(hv, 0);
1613 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1618 HvHASKFLAGS_off(hv);
1623 mro_isa_changed_in(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 */
1701 HE **const orig_array = HvARRAY(hv);
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 remains unchanged throughout the loop. If after freeing all
1720 the entries it turns out that one of the little blighters has triggered
1721 an action that has caused HvARRAY to be re-allocated, then we set
1722 array to the new HvARRAY, and try again. */
1725 /* This is the one we're going to try to empty. First time round
1726 it's the original array. (Hopefully there will only be 1 time
1728 HE ** const array = HvARRAY(hv);
1731 /* Because we have taken xhv_name out, the only allocated pointer
1732 in the aux structure that might exist is the backreference array.
1737 struct mro_meta *meta;
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 if((meta = iter->xhv_mro_meta)) {
1770 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1771 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1772 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1774 iter->xhv_mro_meta = NULL;
1777 /* There are now no allocated pointers in the aux structure. */
1779 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1780 /* What aux structure? */
1783 /* make everyone else think the array is empty, so that the destructors
1784 * called for freed entries can't recusively mess with us */
1787 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1791 /* Loop down the linked list heads */
1792 HE *entry = array[i];
1795 register HE * const oentry = entry;
1796 entry = HeNEXT(entry);
1797 hv_free_ent(hv, oentry);
1801 /* As there are no allocated pointers in the aux structure, it's now
1802 safe to free the array we just cleaned up, if it's not the one we're
1803 going to put back. */
1804 if (array != orig_array) {
1809 /* Good. No-one added anything this time round. */
1814 /* Someone attempted to iterate or set the hash name while we had
1815 the array set to 0. We'll catch backferences on the next time
1816 round the while loop. */
1817 assert(HvARRAY(hv));
1819 if (HvAUX(hv)->xhv_name) {
1820 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1824 if (--attempts == 0) {
1825 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1829 HvARRAY(hv) = orig_array;
1831 /* If the hash was actually a symbol table, put the name back. */
1833 /* We have restored the original array. If name is non-NULL, then
1834 the original array had an aux structure at the end. So this is
1836 SvFLAGS(hv) |= SVf_OOK;
1837 HvAUX(hv)->xhv_name = name;
1842 =for apidoc hv_undef
1850 Perl_hv_undef(pTHX_ HV *hv)
1853 register XPVHV* xhv;
1858 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1859 xhv = (XPVHV*)SvANY(hv);
1861 if ((name = HvNAME_get(hv)) && !PL_dirty)
1862 mro_isa_changed_in(hv);
1867 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1868 hv_name_set(hv, NULL, 0, 0);
1870 SvFLAGS(hv) &= ~SVf_OOK;
1871 Safefree(HvARRAY(hv));
1872 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1874 HvPLACEHOLDERS_set(hv, 0);
1880 static struct xpvhv_aux*
1881 S_hv_auxinit(HV *hv) {
1882 struct xpvhv_aux *iter;
1886 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1887 + sizeof(struct xpvhv_aux), char);
1889 array = (char *) HvARRAY(hv);
1890 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1891 + sizeof(struct xpvhv_aux), char);
1893 HvARRAY(hv) = (HE**) array;
1894 /* SvOOK_on(hv) attacks the IV flags. */
1895 SvFLAGS(hv) |= SVf_OOK;
1898 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1899 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1901 iter->xhv_backreferences = 0;
1902 iter->xhv_mro_meta = NULL;
1907 =for apidoc hv_iterinit
1909 Prepares a starting point to traverse a hash table. Returns the number of
1910 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1911 currently only meaningful for hashes without tie magic.
1913 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1914 hash buckets that happen to be in use. If you still need that esoteric
1915 value, you can get it through the macro C<HvFILL(tb)>.
1922 Perl_hv_iterinit(pTHX_ HV *hv)
1925 Perl_croak(aTHX_ "Bad hash");
1928 struct xpvhv_aux * const iter = HvAUX(hv);
1929 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1930 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1932 hv_free_ent(hv, entry);
1934 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1935 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1940 /* used to be xhv->xhv_fill before 5.004_65 */
1941 return HvTOTALKEYS(hv);
1945 Perl_hv_riter_p(pTHX_ HV *hv) {
1946 struct xpvhv_aux *iter;
1949 Perl_croak(aTHX_ "Bad hash");
1951 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1952 return &(iter->xhv_riter);
1956 Perl_hv_eiter_p(pTHX_ HV *hv) {
1957 struct xpvhv_aux *iter;
1960 Perl_croak(aTHX_ "Bad hash");
1962 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1963 return &(iter->xhv_eiter);
1967 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1968 struct xpvhv_aux *iter;
1971 Perl_croak(aTHX_ "Bad hash");
1979 iter = hv_auxinit(hv);
1981 iter->xhv_riter = riter;
1985 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1986 struct xpvhv_aux *iter;
1989 Perl_croak(aTHX_ "Bad hash");
1994 /* 0 is the default so don't go malloc()ing a new structure just to
1999 iter = hv_auxinit(hv);
2001 iter->xhv_eiter = eiter;
2005 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2008 struct xpvhv_aux *iter;
2011 PERL_UNUSED_ARG(flags);
2014 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2018 if (iter->xhv_name) {
2019 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2025 iter = hv_auxinit(hv);
2027 PERL_HASH(hash, name, len);
2028 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2032 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2033 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2034 PERL_UNUSED_CONTEXT;
2035 return &(iter->xhv_backreferences);
2039 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2045 av = HvAUX(hv)->xhv_backreferences;
2048 HvAUX(hv)->xhv_backreferences = 0;
2049 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2054 hv_iternext is implemented as a macro in hv.h
2056 =for apidoc hv_iternext
2058 Returns entries from a hash iterator. See C<hv_iterinit>.
2060 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2061 iterator currently points to, without losing your place or invalidating your
2062 iterator. Note that in this case the current entry is deleted from the hash
2063 with your iterator holding the last reference to it. Your iterator is flagged
2064 to free the entry on the next call to C<hv_iternext>, so you must not discard
2065 your iterator immediately else the entry will leak - call C<hv_iternext> to
2066 trigger the resource deallocation.
2068 =for apidoc hv_iternext_flags
2070 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2071 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2072 set the placeholders keys (for restricted hashes) will be returned in addition
2073 to normal keys. By default placeholders are automatically skipped over.
2074 Currently a placeholder is implemented with a value that is
2075 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2076 restricted hashes may change, and the implementation currently is
2077 insufficiently abstracted for any change to be tidy.
2083 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2086 register XPVHV* xhv;
2090 struct xpvhv_aux *iter;
2093 Perl_croak(aTHX_ "Bad hash");
2095 xhv = (XPVHV*)SvANY(hv);
2098 /* Too many things (well, pp_each at least) merrily assume that you can
2099 call iv_iternext without calling hv_iterinit, so we'll have to deal
2105 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2106 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2107 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2108 SV * const key = sv_newmortal();
2110 sv_setsv(key, HeSVKEY_force(entry));
2111 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2117 /* one HE per MAGICAL hash */
2118 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2120 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2122 HeKEY_hek(entry) = hek;
2123 HeKLEN(entry) = HEf_SVKEY;
2125 magic_nextpack((SV*) hv,mg,key);
2127 /* force key to stay around until next time */
2128 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2129 return entry; /* beware, hent_val is not set */
2132 SvREFCNT_dec(HeVAL(entry));
2133 Safefree(HeKEY_hek(entry));
2135 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2139 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2140 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2143 /* The prime_env_iter() on VMS just loaded up new hash values
2144 * so the iteration count needs to be reset back to the beginning
2148 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2153 /* hv_iterint now ensures this. */
2154 assert (HvARRAY(hv));
2156 /* At start of hash, entry is NULL. */
2159 entry = HeNEXT(entry);
2160 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2162 * Skip past any placeholders -- don't want to include them in
2165 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2166 entry = HeNEXT(entry);
2171 /* OK. Come to the end of the current list. Grab the next one. */
2173 iter->xhv_riter++; /* HvRITER(hv)++ */
2174 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2175 /* There is no next one. End of the hash. */
2176 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2179 entry = (HvARRAY(hv))[iter->xhv_riter];
2181 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2182 /* If we have an entry, but it's a placeholder, don't count it.
2184 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2185 entry = HeNEXT(entry);
2187 /* Will loop again if this linked list starts NULL
2188 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2189 or if we run through it and find only placeholders. */
2192 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2194 hv_free_ent(hv, oldentry);
2197 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2198 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2200 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2205 =for apidoc hv_iterkey
2207 Returns the key from the current position of the hash iterator. See
2214 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2216 if (HeKLEN(entry) == HEf_SVKEY) {
2218 char * const p = SvPV(HeKEY_sv(entry), len);
2223 *retlen = HeKLEN(entry);
2224 return HeKEY(entry);
2228 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2230 =for apidoc hv_iterkeysv
2232 Returns the key as an C<SV*> from the current position of the hash
2233 iterator. The return value will always be a mortal copy of the key. Also
2240 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2242 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2246 =for apidoc hv_iterval
2248 Returns the value from the current position of the hash iterator. See
2255 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2257 if (SvRMAGICAL(hv)) {
2258 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2259 SV* const sv = sv_newmortal();
2260 if (HeKLEN(entry) == HEf_SVKEY)
2261 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2263 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2267 return HeVAL(entry);
2271 =for apidoc hv_iternextsv
2273 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2280 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2282 HE * const he = hv_iternext_flags(hv, 0);
2286 *key = hv_iterkey(he, retlen);
2287 return hv_iterval(hv, he);
2294 =for apidoc hv_magic
2296 Adds magic to a hash. See C<sv_magic>.
2301 /* possibly free a shared string if no one has access to it
2302 * len and hash must both be valid for str.
2305 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2307 unshare_hek_or_pvn (NULL, str, len, hash);
2312 Perl_unshare_hek(pTHX_ HEK *hek)
2315 unshare_hek_or_pvn(hek, NULL, 0, 0);
2318 /* possibly free a shared string if no one has access to it
2319 hek if non-NULL takes priority over the other 3, else str, len and hash
2320 are used. If so, len and hash must both be valid for str.
2323 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2326 register XPVHV* xhv;
2328 register HE **oentry;
2330 bool is_utf8 = FALSE;
2332 const char * const save = str;
2333 struct shared_he *he = NULL;
2336 /* Find the shared he which is just before us in memory. */
2337 he = (struct shared_he *)(((char *)hek)
2338 - STRUCT_OFFSET(struct shared_he,
2341 /* Assert that the caller passed us a genuine (or at least consistent)
2343 assert (he->shared_he_he.hent_hek == hek);
2346 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2347 --he->shared_he_he.he_valu.hent_refcount;
2348 UNLOCK_STRTAB_MUTEX;
2351 UNLOCK_STRTAB_MUTEX;
2353 hash = HEK_HASH(hek);
2354 } else if (len < 0) {
2355 STRLEN tmplen = -len;
2357 /* See the note in hv_fetch(). --jhi */
2358 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2361 k_flags = HVhek_UTF8;
2363 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2366 /* what follows was the moral equivalent of:
2367 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2369 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2371 xhv = (XPVHV*)SvANY(PL_strtab);
2372 /* assert(xhv_array != 0) */
2374 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2376 const HE *const he_he = &(he->shared_he_he);
2377 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2382 const int flags_masked = k_flags & HVhek_MASK;
2383 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2384 if (HeHASH(entry) != hash) /* strings can't be equal */
2386 if (HeKLEN(entry) != len)
2388 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2390 if (HeKFLAGS(entry) != flags_masked)
2397 if (--entry->he_valu.hent_refcount == 0) {
2398 *oentry = HeNEXT(entry);
2400 /* There are now no entries in our slot. */
2401 xhv->xhv_fill--; /* HvFILL(hv)-- */
2404 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2408 UNLOCK_STRTAB_MUTEX;
2409 if (!entry && ckWARN_d(WARN_INTERNAL))
2410 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2411 "Attempt to free non-existent shared string '%s'%s"
2413 hek ? HEK_KEY(hek) : str,
2414 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2415 if (k_flags & HVhek_FREEKEY)
2419 /* get a (constant) string ptr from the global string table
2420 * string will get added if it is not already there.
2421 * len and hash must both be valid for str.
2424 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2426 bool is_utf8 = FALSE;
2428 const char * const save = str;
2431 STRLEN tmplen = -len;
2433 /* See the note in hv_fetch(). --jhi */
2434 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2436 /* If we were able to downgrade here, then than means that we were passed
2437 in a key which only had chars 0-255, but was utf8 encoded. */
2440 /* If we found we were able to downgrade the string to bytes, then
2441 we should flag that it needs upgrading on keys or each. Also flag
2442 that we need share_hek_flags to free the string. */
2444 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2447 return share_hek_flags (str, len, hash, flags);
2451 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2455 const int flags_masked = flags & HVhek_MASK;
2456 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2458 /* what follows is the moral equivalent of:
2460 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2461 hv_store(PL_strtab, str, len, NULL, hash);
2463 Can't rehash the shared string table, so not sure if it's worth
2464 counting the number of entries in the linked list
2466 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2467 /* assert(xhv_array != 0) */
2469 entry = (HvARRAY(PL_strtab))[hindex];
2470 for (;entry; entry = HeNEXT(entry)) {
2471 if (HeHASH(entry) != hash) /* strings can't be equal */
2473 if (HeKLEN(entry) != len)
2475 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2477 if (HeKFLAGS(entry) != flags_masked)
2483 /* What used to be head of the list.
2484 If this is NULL, then we're the first entry for this slot, which
2485 means we need to increate fill. */
2486 struct shared_he *new_entry;
2489 HE **const head = &HvARRAY(PL_strtab)[hindex];
2490 HE *const next = *head;
2492 /* We don't actually store a HE from the arena and a regular HEK.
2493 Instead we allocate one chunk of memory big enough for both,
2494 and put the HEK straight after the HE. This way we can find the
2495 HEK directly from the HE.
2498 Newx(k, STRUCT_OFFSET(struct shared_he,
2499 shared_he_hek.hek_key[0]) + len + 2, char);
2500 new_entry = (struct shared_he *)k;
2501 entry = &(new_entry->shared_he_he);
2502 hek = &(new_entry->shared_he_hek);
2504 Copy(str, HEK_KEY(hek), len, char);
2505 HEK_KEY(hek)[len] = 0;
2507 HEK_HASH(hek) = hash;
2508 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2510 /* Still "point" to the HEK, so that other code need not know what
2512 HeKEY_hek(entry) = hek;
2513 entry->he_valu.hent_refcount = 0;
2514 HeNEXT(entry) = next;
2517 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2518 if (!next) { /* initial entry? */
2519 xhv->xhv_fill++; /* HvFILL(hv)++ */
2520 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2525 ++entry->he_valu.hent_refcount;
2526 UNLOCK_STRTAB_MUTEX;
2528 if (flags & HVhek_FREEKEY)
2531 return HeKEY_hek(entry);
2535 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, const char *const key,
2536 const STRLEN klen, const int k_flags, int action)
2539 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2540 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2541 if (uf->uf_set == NULL) {
2542 SV* obj = mg->mg_obj;
2545 keysv = sv_2mortal(newSVpvn(key, klen));
2546 if (k_flags & HVhek_UTF8)
2550 mg->mg_obj = keysv; /* pass key */
2551 uf->uf_index = action; /* pass action */
2552 magic_getuvar((SV*)hv, mg);
2553 keysv = mg->mg_obj; /* may have changed */
2561 Perl_hv_placeholders_p(pTHX_ HV *hv)
2564 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2567 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2570 Perl_die(aTHX_ "panic: hv_placeholders_p");
2573 return &(mg->mg_len);
2578 Perl_hv_placeholders_get(pTHX_ HV *hv)
2581 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2583 return mg ? mg->mg_len : 0;
2587 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2590 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2595 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2596 Perl_die(aTHX_ "panic: hv_placeholders_set");
2598 /* else we don't need to add magic to record 0 placeholders. */
2602 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2606 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2611 value = &PL_sv_placeholder;
2614 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2617 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2620 case HVrhek_PV_UTF8:
2621 /* Create a string SV that directly points to the bytes in our
2623 value = newSV_type(SVt_PV);
2624 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2625 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2626 /* This stops anything trying to free it */
2627 SvLEN_set(value, 0);
2629 SvREADONLY_on(value);
2630 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2634 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2635 he->refcounted_he_data[0]);
2641 =for apidoc refcounted_he_chain_2hv
2643 Generates and returns a C<HV *> by walking up the tree starting at the passed
2644 in C<struct refcounted_he *>.
2649 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2653 U32 placeholders = 0;
2654 /* We could chase the chain once to get an idea of the number of keys,
2655 and call ksplit. But for now we'll make a potentially inefficient
2656 hash with only 8 entries in its array. */
2657 const U32 max = HvMAX(hv);
2661 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2662 HvARRAY(hv) = (HE**)array;
2667 U32 hash = chain->refcounted_he_hash;
2669 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2671 HE **oentry = &((HvARRAY(hv))[hash & max]);
2672 HE *entry = *oentry;
2675 for (; entry; entry = HeNEXT(entry)) {
2676 if (HeHASH(entry) == hash) {
2677 /* We might have a duplicate key here. If so, entry is older
2678 than the key we've already put in the hash, so if they are
2679 the same, skip adding entry. */
2681 const STRLEN klen = HeKLEN(entry);
2682 const char *const key = HeKEY(entry);
2683 if (klen == chain->refcounted_he_keylen
2684 && (!!HeKUTF8(entry)
2685 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2686 && memEQ(key, REF_HE_KEY(chain), klen))
2689 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2691 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2692 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2693 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2704 = share_hek_flags(REF_HE_KEY(chain),
2705 chain->refcounted_he_keylen,
2706 chain->refcounted_he_hash,
2707 (chain->refcounted_he_data[0]
2708 & (HVhek_UTF8|HVhek_WASUTF8)));
2710 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2712 value = refcounted_he_value(chain);
2713 if (value == &PL_sv_placeholder)
2715 HeVAL(entry) = value;
2717 /* Link it into the chain. */
2718 HeNEXT(entry) = *oentry;
2719 if (!HeNEXT(entry)) {
2720 /* initial entry. */
2728 chain = chain->refcounted_he_next;
2732 clear_placeholders(hv, placeholders);
2733 HvTOTALKEYS(hv) -= placeholders;
2736 /* We could check in the loop to see if we encounter any keys with key
2737 flags, but it's probably not worth it, as this per-hash flag is only
2738 really meant as an optimisation for things like Storable. */
2740 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2746 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2747 const char *key, STRLEN klen, int flags, U32 hash)
2750 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2751 of your key has to exactly match that which is stored. */
2752 SV *value = &PL_sv_placeholder;
2756 if (flags & HVhek_FREEKEY)
2758 key = SvPV_const(keysv, klen);
2760 is_utf8 = (SvUTF8(keysv) != 0);
2762 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2766 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2767 hash = SvSHARED_HASH(keysv);
2769 PERL_HASH(hash, key, klen);
2773 for (; chain; chain = chain->refcounted_he_next) {
2775 if (hash != chain->refcounted_he_hash)
2777 if (klen != chain->refcounted_he_keylen)
2779 if (memNE(REF_HE_KEY(chain),key,klen))
2781 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2784 if (hash != HEK_HASH(chain->refcounted_he_hek))
2786 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2788 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2790 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2794 value = sv_2mortal(refcounted_he_value(chain));
2798 if (flags & HVhek_FREEKEY)
2805 =for apidoc refcounted_he_new
2807 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2808 stored in a compact form, all references remain the property of the caller.
2809 The C<struct refcounted_he> is returned with a reference count of 1.
2814 struct refcounted_he *
2815 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2816 SV *const key, SV *const value) {
2818 struct refcounted_he *he;
2820 const char *key_p = SvPV_const(key, key_len);
2821 STRLEN value_len = 0;
2822 const char *value_p = NULL;
2827 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2830 value_type = HVrhek_PV;
2831 } else if (SvIOK(value)) {
2832 value_type = HVrhek_IV;
2833 } else if (value == &PL_sv_placeholder) {
2834 value_type = HVrhek_delete;
2835 } else if (!SvOK(value)) {
2836 value_type = HVrhek_undef;
2838 value_type = HVrhek_PV;
2841 if (value_type == HVrhek_PV) {
2842 value_p = SvPV_const(value, value_len);
2843 key_offset = value_len + 2;
2850 he = (struct refcounted_he*)
2851 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2855 he = (struct refcounted_he*)
2856 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2861 he->refcounted_he_next = parent;
2863 if (value_type == HVrhek_PV) {
2864 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2865 he->refcounted_he_val.refcounted_he_u_len = value_len;
2866 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2867 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2869 value_type = HVrhek_PV_UTF8;
2870 } else if (value_type == HVrhek_IV) {
2872 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2873 value_type = HVrhek_UV;
2875 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2881 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2882 As we're going to be building hash keys from this value in future,
2883 normalise it now. */
2884 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2885 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2887 PERL_HASH(hash, key_p, key_len);
2890 he->refcounted_he_hash = hash;
2891 he->refcounted_he_keylen = key_len;
2892 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2894 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2897 if (flags & HVhek_WASUTF8) {
2898 /* If it was downgraded from UTF-8, then the pointer returned from
2899 bytes_from_utf8 is an allocated pointer that we must free. */
2903 he->refcounted_he_data[0] = flags;
2904 he->refcounted_he_refcnt = 1;
2910 =for apidoc refcounted_he_free
2912 Decrements the reference count of the passed in C<struct refcounted_he *>
2913 by one. If the reference count reaches zero the structure's memory is freed,
2914 and C<refcounted_he_free> iterates onto the parent node.
2920 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2922 PERL_UNUSED_CONTEXT;
2925 struct refcounted_he *copy;
2929 new_count = --he->refcounted_he_refcnt;
2930 HINTS_REFCNT_UNLOCK;
2936 #ifndef USE_ITHREADS
2937 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2940 he = he->refcounted_he_next;
2941 PerlMemShared_free(copy);
2946 =for apidoc hv_assert
2948 Check that a hash is in an internally consistent state.
2956 Perl_hv_assert(pTHX_ HV *hv)
2961 int placeholders = 0;
2964 const I32 riter = HvRITER_get(hv);
2965 HE *eiter = HvEITER_get(hv);
2967 (void)hv_iterinit(hv);
2969 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2970 /* sanity check the values */
2971 if (HeVAL(entry) == &PL_sv_placeholder)
2975 /* sanity check the keys */
2976 if (HeSVKEY(entry)) {
2977 NOOP; /* Don't know what to check on SV keys. */
2978 } else if (HeKUTF8(entry)) {
2980 if (HeKWASUTF8(entry)) {
2981 PerlIO_printf(Perl_debug_log,
2982 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2983 (int) HeKLEN(entry), HeKEY(entry));
2986 } else if (HeKWASUTF8(entry))
2989 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2990 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2991 const int nhashkeys = HvUSEDKEYS(hv);
2992 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2994 if (nhashkeys != real) {
2995 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2998 if (nhashplaceholders != placeholders) {
2999 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3003 if (withflags && ! HvHASKFLAGS(hv)) {
3004 PerlIO_printf(Perl_debug_log,
3005 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3012 HvRITER_set(hv, riter); /* Restore hash iterator state */
3013 HvEITER_set(hv, eiter);
3020 * c-indentation-style: bsd
3022 * indent-tabs-mode: t
3025 * ex: set ts=8 sts=4 sw=4 noet: