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)
427 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
428 keysv = hv_magic_uvar_xkey(hv, keysv, action);
429 if (flags & HVhek_FREEKEY)
431 key = SvPV_const(keysv, klen);
433 is_utf8 = (SvUTF8(keysv) != 0);
435 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
438 xhv = (XPVHV*)SvANY(hv);
440 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
441 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
443 /* XXX should be able to skimp on the HE/HEK here when
444 HV_FETCH_JUST_SV is true. */
446 keysv = newSVpvn(key, klen);
451 keysv = newSVsv(keysv);
454 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
456 /* grab a fake HE/HEK pair from the pool or make a new one */
457 entry = PL_hv_fetch_ent_mh;
459 PL_hv_fetch_ent_mh = HeNEXT(entry);
463 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
464 HeKEY_hek(entry) = (HEK*)k;
466 HeNEXT(entry) = NULL;
467 HeSVKEY_set(entry, keysv);
469 sv_upgrade(sv, SVt_PVLV);
471 /* so we can free entry when freeing sv */
472 LvTARG(sv) = (SV*)entry;
474 /* XXX remove at some point? */
475 if (flags & HVhek_FREEKEY)
480 #ifdef ENV_IS_CASELESS
481 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
483 for (i = 0; i < klen; ++i)
484 if (isLOWER(key[i])) {
485 /* Would be nice if we had a routine to do the
486 copy and upercase in a single pass through. */
487 const char * const nkey = strupr(savepvn(key,klen));
488 /* Note that this fetch is for nkey (the uppercased
489 key) whereas the store is for key (the original) */
490 entry = hv_fetch_common(hv, NULL, nkey, klen,
491 HVhek_FREEKEY, /* free nkey */
492 0 /* non-LVAL fetch */,
494 0 /* compute hash */);
495 if (!entry && (action & HV_FETCH_LVALUE)) {
496 /* This call will free key if necessary.
497 Do it this way to encourage compiler to tail
499 entry = hv_fetch_common(hv, keysv, key, klen,
500 flags, HV_FETCH_ISSTORE,
503 if (flags & HVhek_FREEKEY)
511 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
512 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
513 /* I don't understand why hv_exists_ent has svret and sv,
514 whereas hv_exists only had one. */
515 SV * const svret = sv_newmortal();
518 if (keysv || is_utf8) {
520 keysv = newSVpvn(key, klen);
523 keysv = newSVsv(keysv);
525 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
527 mg_copy((SV*)hv, sv, key, klen);
529 if (flags & HVhek_FREEKEY)
531 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
532 /* This cast somewhat evil, but I'm merely using NULL/
533 not NULL to return the boolean exists.
534 And I know hv is not NULL. */
535 return SvTRUE(svret) ? (HE *)hv : NULL;
537 #ifdef ENV_IS_CASELESS
538 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
539 /* XXX This code isn't UTF8 clean. */
540 char * const keysave = (char * const)key;
541 /* Will need to free this, so set FREEKEY flag. */
542 key = savepvn(key,klen);
543 key = (const char*)strupr((char*)key);
548 if (flags & HVhek_FREEKEY) {
551 flags |= HVhek_FREEKEY;
555 else if (action & HV_FETCH_ISSTORE) {
558 hv_magic_check (hv, &needs_copy, &needs_store);
560 const bool save_taint = PL_tainted;
561 if (keysv || is_utf8) {
563 keysv = newSVpvn(key, klen);
567 PL_tainted = SvTAINTED(keysv);
568 keysv = sv_2mortal(newSVsv(keysv));
569 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
571 mg_copy((SV*)hv, val, key, klen);
574 TAINT_IF(save_taint);
576 if (flags & HVhek_FREEKEY)
580 #ifdef ENV_IS_CASELESS
581 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
582 /* XXX This code isn't UTF8 clean. */
583 const char *keysave = key;
584 /* Will need to free this, so set FREEKEY flag. */
585 key = savepvn(key,klen);
586 key = (const char*)strupr((char*)key);
591 if (flags & HVhek_FREEKEY) {
594 flags |= HVhek_FREEKEY;
602 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
603 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
604 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
609 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
611 HvARRAY(hv) = (HE**)array;
613 #ifdef DYNAMIC_ENV_FETCH
614 else if (action & HV_FETCH_ISEXISTS) {
615 /* for an %ENV exists, if we do an insert it's by a recursive
616 store call, so avoid creating HvARRAY(hv) right now. */
620 /* XXX remove at some point? */
621 if (flags & HVhek_FREEKEY)
629 char * const keysave = (char *)key;
630 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
634 flags &= ~HVhek_UTF8;
635 if (key != keysave) {
636 if (flags & HVhek_FREEKEY)
638 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
643 PERL_HASH_INTERNAL(hash, key, klen);
644 /* We don't have a pointer to the hv, so we have to replicate the
645 flag into every HEK, so that hv_iterkeysv can see it. */
646 /* And yes, you do need this even though you are not "storing" because
647 you can flip the flags below if doing an lval lookup. (And that
648 was put in to give the semantics Andreas was expecting.) */
649 flags |= HVhek_REHASH;
651 if (keysv && (SvIsCOW_shared_hash(keysv))) {
652 hash = SvSHARED_HASH(keysv);
654 PERL_HASH(hash, key, klen);
658 masked_flags = (flags & HVhek_MASK);
660 #ifdef DYNAMIC_ENV_FETCH
661 if (!HvARRAY(hv)) entry = NULL;
665 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
667 for (; entry; entry = HeNEXT(entry)) {
668 if (HeHASH(entry) != hash) /* strings can't be equal */
670 if (HeKLEN(entry) != (I32)klen)
672 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
674 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
677 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
678 if (HeKFLAGS(entry) != masked_flags) {
679 /* We match if HVhek_UTF8 bit in our flags and hash key's
680 match. But if entry was set previously with HVhek_WASUTF8
681 and key now doesn't (or vice versa) then we should change
682 the key's flag, as this is assignment. */
683 if (HvSHAREKEYS(hv)) {
684 /* Need to swap the key we have for a key with the flags we
685 need. As keys are shared we can't just write to the
686 flag, so we share the new one, unshare the old one. */
687 HEK * const new_hek = share_hek_flags(key, klen, hash,
689 unshare_hek (HeKEY_hek(entry));
690 HeKEY_hek(entry) = new_hek;
692 else if (hv == PL_strtab) {
693 /* PL_strtab is usually the only hash without HvSHAREKEYS,
694 so putting this test here is cheap */
695 if (flags & HVhek_FREEKEY)
697 Perl_croak(aTHX_ S_strtab_error,
698 action & HV_FETCH_LVALUE ? "fetch" : "store");
701 HeKFLAGS(entry) = masked_flags;
702 if (masked_flags & HVhek_ENABLEHVKFLAGS)
705 if (HeVAL(entry) == &PL_sv_placeholder) {
706 /* yes, can store into placeholder slot */
707 if (action & HV_FETCH_LVALUE) {
709 /* This preserves behaviour with the old hv_fetch
710 implementation which at this point would bail out
711 with a break; (at "if we find a placeholder, we
712 pretend we haven't found anything")
714 That break mean that if a placeholder were found, it
715 caused a call into hv_store, which in turn would
716 check magic, and if there is no magic end up pretty
717 much back at this point (in hv_store's code). */
720 /* LVAL fetch which actaully needs a store. */
722 HvPLACEHOLDERS(hv)--;
725 if (val != &PL_sv_placeholder)
726 HvPLACEHOLDERS(hv)--;
729 } else if (action & HV_FETCH_ISSTORE) {
730 SvREFCNT_dec(HeVAL(entry));
733 } else if (HeVAL(entry) == &PL_sv_placeholder) {
734 /* if we find a placeholder, we pretend we haven't found
738 if (flags & HVhek_FREEKEY)
742 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
743 if (!(action & HV_FETCH_ISSTORE)
744 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
746 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
748 sv = newSVpvn(env,len);
750 return hv_fetch_common(hv,keysv,key,klen,flags,HV_FETCH_ISSTORE,sv,
756 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
757 hv_notallowed(flags, key, klen,
758 "Attempt to access disallowed key '%"SVf"' in"
759 " a restricted hash");
761 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
762 /* Not doing some form of store, so return failure. */
763 if (flags & HVhek_FREEKEY)
767 if (action & HV_FETCH_LVALUE) {
770 /* At this point the old hv_fetch code would call to hv_store,
771 which in turn might do some tied magic. So we need to make that
772 magic check happen. */
773 /* gonna assign to this, so it better be there */
774 return hv_fetch_common(hv, keysv, key, klen, flags,
775 HV_FETCH_ISSTORE, val, hash);
776 /* XXX Surely that could leak if the fetch-was-store fails?
777 Just like the hv_fetch. */
781 /* Welcome to hv_store... */
784 /* Not sure if we can get here. I think the only case of oentry being
785 NULL is for %ENV with dynamic env fetch. But that should disappear
786 with magic in the previous code. */
789 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
791 HvARRAY(hv) = (HE**)array;
794 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
797 /* share_hek_flags will do the free for us. This might be considered
800 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
801 else if (hv == PL_strtab) {
802 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
803 this test here is cheap */
804 if (flags & HVhek_FREEKEY)
806 Perl_croak(aTHX_ S_strtab_error,
807 action & HV_FETCH_LVALUE ? "fetch" : "store");
809 else /* gotta do the real thing */
810 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
812 HeNEXT(entry) = *oentry;
815 if (val == &PL_sv_placeholder)
816 HvPLACEHOLDERS(hv)++;
817 if (masked_flags & HVhek_ENABLEHVKFLAGS)
821 const HE *counter = HeNEXT(entry);
823 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
824 if (!counter) { /* initial entry? */
825 xhv->xhv_fill++; /* HvFILL(hv)++ */
826 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
828 } else if(!HvREHASH(hv)) {
831 while ((counter = HeNEXT(counter)))
834 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
835 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
836 bucket splits on a rehashed hash, as we're not going to
837 split it again, and if someone is lucky (evil) enough to
838 get all the keys in one list they could exhaust our memory
839 as we repeatedly double the number of buckets on every
840 entry. Linear search feels a less worse thing to do. */
850 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
852 const MAGIC *mg = SvMAGIC(hv);
856 if (isUPPER(mg->mg_type)) {
858 if (mg->mg_type == PERL_MAGIC_tied) {
859 *needs_store = FALSE;
860 return; /* We've set all there is to set. */
863 mg = mg->mg_moremagic;
868 =for apidoc hv_scalar
870 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
876 Perl_hv_scalar(pTHX_ HV *hv)
880 if (SvRMAGICAL(hv)) {
881 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
883 return magic_scalarpack(hv, mg);
888 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
889 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
897 =for apidoc hv_delete
899 Deletes a key/value pair in the hash. The value SV is removed from the
900 hash and returned to the caller. The C<klen> is the length of the key.
901 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
908 Perl_hv_delete(pTHX_ HV *hv, const char *key, I32 klen_i32, I32 flags)
915 k_flags = HVhek_UTF8;
920 return hv_delete_common(hv, NULL, key, klen, k_flags, flags, 0);
924 =for apidoc hv_delete_ent
926 Deletes a key/value pair in the hash. The value SV is removed from the
927 hash and returned to the caller. The C<flags> value will normally be zero;
928 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
929 precomputed hash value, or 0 to ask for it to be computed.
934 /* XXX This looks like an ideal candidate to inline */
936 Perl_hv_delete_ent(pTHX_ HV *hv, SV *keysv, I32 flags, U32 hash)
938 return hv_delete_common(hv, keysv, NULL, 0, 0, flags, hash);
942 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
943 int k_flags, I32 d_flags, U32 hash)
948 register HE **oentry;
949 HE *const *first_entry;
957 if (SvSMAGICAL(hv) && SvGMAGICAL(hv))
958 keysv = hv_magic_uvar_xkey(hv, keysv, HV_DELETE);
959 if (k_flags & HVhek_FREEKEY)
961 key = SvPV_const(keysv, klen);
963 is_utf8 = (SvUTF8(keysv) != 0);
965 is_utf8 = ((k_flags & HVhek_UTF8) ? TRUE : FALSE);
968 if (SvRMAGICAL(hv)) {
971 hv_magic_check (hv, &needs_copy, &needs_store);
975 entry = hv_fetch_common(hv, keysv, key, klen,
976 k_flags & ~HVhek_FREEKEY, HV_FETCH_LVALUE,
978 sv = entry ? HeVAL(entry) : NULL;
984 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
985 /* No longer an element */
986 sv_unmagic(sv, PERL_MAGIC_tiedelem);
989 return NULL; /* element cannot be deleted */
991 #ifdef ENV_IS_CASELESS
992 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
993 /* XXX This code isn't UTF8 clean. */
994 keysv = sv_2mortal(newSVpvn(key,klen));
995 if (k_flags & HVhek_FREEKEY) {
998 key = strupr(SvPVX(keysv));
1007 xhv = (XPVHV*)SvANY(hv);
1012 const char * const keysave = key;
1013 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1016 k_flags |= HVhek_UTF8;
1018 k_flags &= ~HVhek_UTF8;
1019 if (key != keysave) {
1020 if (k_flags & HVhek_FREEKEY) {
1021 /* This shouldn't happen if our caller does what we expect,
1022 but strictly the API allows it. */
1025 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1027 HvHASKFLAGS_on((SV*)hv);
1031 PERL_HASH_INTERNAL(hash, key, klen);
1033 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1034 hash = SvSHARED_HASH(keysv);
1036 PERL_HASH(hash, key, klen);
1040 masked_flags = (k_flags & HVhek_MASK);
1042 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1044 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1046 if (HeHASH(entry) != hash) /* strings can't be equal */
1048 if (HeKLEN(entry) != (I32)klen)
1050 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1052 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1055 if (hv == PL_strtab) {
1056 if (k_flags & HVhek_FREEKEY)
1058 Perl_croak(aTHX_ S_strtab_error, "delete");
1061 /* if placeholder is here, it's already been deleted.... */
1062 if (HeVAL(entry) == &PL_sv_placeholder) {
1063 if (k_flags & HVhek_FREEKEY)
1067 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1068 hv_notallowed(k_flags, key, klen,
1069 "Attempt to delete readonly key '%"SVf"' from"
1070 " a restricted hash");
1072 if (k_flags & HVhek_FREEKEY)
1075 if (d_flags & G_DISCARD)
1078 sv = sv_2mortal(HeVAL(entry));
1079 HeVAL(entry) = &PL_sv_placeholder;
1083 * If a restricted hash, rather than really deleting the entry, put
1084 * a placeholder there. This marks the key as being "approved", so
1085 * we can still access via not-really-existing key without raising
1088 if (SvREADONLY(hv)) {
1089 SvREFCNT_dec(HeVAL(entry));
1090 HeVAL(entry) = &PL_sv_placeholder;
1091 /* We'll be saving this slot, so the number of allocated keys
1092 * doesn't go down, but the number placeholders goes up */
1093 HvPLACEHOLDERS(hv)++;
1095 *oentry = HeNEXT(entry);
1097 xhv->xhv_fill--; /* HvFILL(hv)-- */
1099 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1102 hv_free_ent(hv, entry);
1103 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1104 if (xhv->xhv_keys == 0)
1105 HvHASKFLAGS_off(hv);
1109 if (SvREADONLY(hv)) {
1110 hv_notallowed(k_flags, key, klen,
1111 "Attempt to delete disallowed key '%"SVf"' from"
1112 " a restricted hash");
1115 if (k_flags & HVhek_FREEKEY)
1121 S_hsplit(pTHX_ HV *hv)
1124 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1125 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1126 register I32 newsize = oldsize * 2;
1128 char *a = (char*) HvARRAY(hv);
1130 register HE **oentry;
1131 int longest_chain = 0;
1134 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1135 (void*)hv, (int) oldsize);*/
1137 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1138 /* Can make this clear any placeholders first for non-restricted hashes,
1139 even though Storable rebuilds restricted hashes by putting in all the
1140 placeholders (first) before turning on the readonly flag, because
1141 Storable always pre-splits the hash. */
1142 hv_clear_placeholders(hv);
1146 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1147 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1148 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1154 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1157 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1158 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1163 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1165 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1167 if (oldsize >= 64) {
1168 offer_nice_chunk(HvARRAY(hv),
1169 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1170 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1173 Safefree(HvARRAY(hv));
1177 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1178 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1179 HvARRAY(hv) = (HE**) a;
1182 for (i=0; i<oldsize; i++,aep++) {
1183 int left_length = 0;
1184 int right_length = 0;
1188 if (!*aep) /* non-existent */
1191 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1192 if ((HeHASH(entry) & newsize) != (U32)i) {
1193 *oentry = HeNEXT(entry);
1194 HeNEXT(entry) = *bep;
1196 xhv->xhv_fill++; /* HvFILL(hv)++ */
1202 oentry = &HeNEXT(entry);
1206 if (!*aep) /* everything moved */
1207 xhv->xhv_fill--; /* HvFILL(hv)-- */
1208 /* I think we don't actually need to keep track of the longest length,
1209 merely flag if anything is too long. But for the moment while
1210 developing this code I'll track it. */
1211 if (left_length > longest_chain)
1212 longest_chain = left_length;
1213 if (right_length > longest_chain)
1214 longest_chain = right_length;
1218 /* Pick your policy for "hashing isn't working" here: */
1219 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1224 if (hv == PL_strtab) {
1225 /* Urg. Someone is doing something nasty to the string table.
1230 /* Awooga. Awooga. Pathological data. */
1231 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1232 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1235 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1236 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1238 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1241 was_shared = HvSHAREKEYS(hv);
1244 HvSHAREKEYS_off(hv);
1249 for (i=0; i<newsize; i++,aep++) {
1250 register HE *entry = *aep;
1252 /* We're going to trash this HE's next pointer when we chain it
1253 into the new hash below, so store where we go next. */
1254 HE * const next = HeNEXT(entry);
1259 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1264 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1265 hash, HeKFLAGS(entry));
1266 unshare_hek (HeKEY_hek(entry));
1267 HeKEY_hek(entry) = new_hek;
1269 /* Not shared, so simply write the new hash in. */
1270 HeHASH(entry) = hash;
1272 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1273 HEK_REHASH_on(HeKEY_hek(entry));
1274 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1276 /* Copy oentry to the correct new chain. */
1277 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1279 xhv->xhv_fill++; /* HvFILL(hv)++ */
1280 HeNEXT(entry) = *bep;
1286 Safefree (HvARRAY(hv));
1287 HvARRAY(hv) = (HE **)a;
1291 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1294 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1295 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1296 register I32 newsize;
1301 register HE **oentry;
1303 newsize = (I32) newmax; /* possible truncation here */
1304 if (newsize != newmax || newmax <= oldsize)
1306 while ((newsize & (1 + ~newsize)) != newsize) {
1307 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1309 if (newsize < newmax)
1311 if (newsize < newmax)
1312 return; /* overflow detection */
1314 a = (char *) HvARRAY(hv);
1317 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1318 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1319 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1325 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1328 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1329 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1334 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1336 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1338 if (oldsize >= 64) {
1339 offer_nice_chunk(HvARRAY(hv),
1340 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1341 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1344 Safefree(HvARRAY(hv));
1347 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1350 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1352 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1353 HvARRAY(hv) = (HE **) a;
1354 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1358 for (i=0; i<oldsize; i++,aep++) {
1359 if (!*aep) /* non-existent */
1361 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1362 register I32 j = (HeHASH(entry) & newsize);
1366 *oentry = HeNEXT(entry);
1367 if (!(HeNEXT(entry) = aep[j]))
1368 xhv->xhv_fill++; /* HvFILL(hv)++ */
1373 oentry = &HeNEXT(entry);
1375 if (!*aep) /* everything moved */
1376 xhv->xhv_fill--; /* HvFILL(hv)-- */
1383 Creates a new HV. The reference count is set to 1.
1391 register XPVHV* xhv;
1392 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1393 xhv = (XPVHV*)SvANY(hv);
1395 #ifndef NODEFAULT_SHAREKEYS
1396 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1399 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1400 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1405 Perl_newHVhv(pTHX_ HV *ohv)
1407 HV * const hv = newHV();
1408 STRLEN hv_max, hv_fill;
1410 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1412 hv_max = HvMAX(ohv);
1414 if (!SvMAGICAL((SV *)ohv)) {
1415 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1417 const bool shared = !!HvSHAREKEYS(ohv);
1418 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1420 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1423 /* In each bucket... */
1424 for (i = 0; i <= hv_max; i++) {
1426 HE *oent = oents[i];
1433 /* Copy the linked list of entries. */
1434 for (; oent; oent = HeNEXT(oent)) {
1435 const U32 hash = HeHASH(oent);
1436 const char * const key = HeKEY(oent);
1437 const STRLEN len = HeKLEN(oent);
1438 const int flags = HeKFLAGS(oent);
1439 HE * const ent = new_HE();
1441 HeVAL(ent) = newSVsv(HeVAL(oent));
1443 = shared ? share_hek_flags(key, len, hash, flags)
1444 : save_hek_flags(key, len, hash, flags);
1455 HvFILL(hv) = hv_fill;
1456 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1460 /* Iterate over ohv, copying keys and values one at a time. */
1462 const I32 riter = HvRITER_get(ohv);
1463 HE * const eiter = HvEITER_get(ohv);
1465 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1466 while (hv_max && hv_max + 1 >= hv_fill * 2)
1467 hv_max = hv_max / 2;
1471 while ((entry = hv_iternext_flags(ohv, 0))) {
1472 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1473 newSVsv(HeVAL(entry)), HeHASH(entry),
1476 HvRITER_set(ohv, riter);
1477 HvEITER_set(ohv, eiter);
1483 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1484 magic stays on it. */
1486 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1488 HV * const hv = newHV();
1491 if (ohv && (hv_fill = HvFILL(ohv))) {
1492 STRLEN hv_max = HvMAX(ohv);
1494 const I32 riter = HvRITER_get(ohv);
1495 HE * const eiter = HvEITER_get(ohv);
1497 while (hv_max && hv_max + 1 >= hv_fill * 2)
1498 hv_max = hv_max / 2;
1502 while ((entry = hv_iternext_flags(ohv, 0))) {
1503 SV *const sv = newSVsv(HeVAL(entry));
1504 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1505 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1506 hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1507 sv, HeHASH(entry), HeKFLAGS(entry));
1509 HvRITER_set(ohv, riter);
1510 HvEITER_set(ohv, eiter);
1512 hv_magic(hv, NULL, PERL_MAGIC_hints);
1517 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1521 I32 isa_changing = 0;
1527 if(HvNAME_get(hv) && val && isGV(val)) {
1529 mro_method_changed_in(hv); /* deletion of method from stash */
1530 else if(GvAV((GV*)val) && strEQ(GvNAME((GV*)val), "ISA"))
1535 if (HeKLEN(entry) == HEf_SVKEY) {
1536 SvREFCNT_dec(HeKEY_sv(entry));
1537 Safefree(HeKEY_hek(entry));
1539 else if (HvSHAREKEYS(hv))
1540 unshare_hek(HeKEY_hek(entry));
1542 Safefree(HeKEY_hek(entry));
1545 if(isa_changing) mro_isa_changed_in(hv); /* deletion of @ISA from stash */
1549 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1554 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1555 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1556 if (HeKLEN(entry) == HEf_SVKEY) {
1557 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1559 hv_free_ent(hv, entry);
1563 =for apidoc hv_clear
1565 Clears a hash, making it empty.
1571 Perl_hv_clear(pTHX_ HV *hv)
1574 register XPVHV* xhv;
1578 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1580 xhv = (XPVHV*)SvANY(hv);
1582 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1583 /* restricted hash: convert all keys to placeholders */
1585 for (i = 0; i <= xhv->xhv_max; i++) {
1586 HE *entry = (HvARRAY(hv))[i];
1587 for (; entry; entry = HeNEXT(entry)) {
1588 /* not already placeholder */
1589 if (HeVAL(entry) != &PL_sv_placeholder) {
1590 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1591 SV* const keysv = hv_iterkeysv(entry);
1593 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1596 SvREFCNT_dec(HeVAL(entry));
1597 HeVAL(entry) = &PL_sv_placeholder;
1598 HvPLACEHOLDERS(hv)++;
1606 HvPLACEHOLDERS_set(hv, 0);
1608 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1613 HvHASKFLAGS_off(hv);
1618 mro_isa_changed_in(hv);
1619 HvEITER_set(hv, NULL);
1624 =for apidoc hv_clear_placeholders
1626 Clears any placeholders from a hash. If a restricted hash has any of its keys
1627 marked as readonly and the key is subsequently deleted, the key is not actually
1628 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1629 it so it will be ignored by future operations such as iterating over the hash,
1630 but will still allow the hash to have a value reassigned to the key at some
1631 future point. This function clears any such placeholder keys from the hash.
1632 See Hash::Util::lock_keys() for an example of its use.
1638 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1641 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1644 clear_placeholders(hv, items);
1648 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1658 /* Loop down the linked list heads */
1660 HE **oentry = &(HvARRAY(hv))[i];
1663 while ((entry = *oentry)) {
1664 if (HeVAL(entry) == &PL_sv_placeholder) {
1665 *oentry = HeNEXT(entry);
1666 if (first && !*oentry)
1667 HvFILL(hv)--; /* This linked list is now empty. */
1668 if (entry == HvEITER_get(hv))
1671 hv_free_ent(hv, entry);
1675 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1676 if (HvKEYS(hv) == 0)
1677 HvHASKFLAGS_off(hv);
1678 HvPLACEHOLDERS_set(hv, 0);
1682 oentry = &HeNEXT(entry);
1687 /* You can't get here, hence assertion should always fail. */
1688 assert (items == 0);
1693 S_hfreeentries(pTHX_ HV *hv)
1695 /* This is the array that we're going to restore */
1696 HE **const orig_array = HvARRAY(hv);
1704 /* If the hash is actually a symbol table with a name, look after the
1706 struct xpvhv_aux *iter = HvAUX(hv);
1708 name = iter->xhv_name;
1709 iter->xhv_name = NULL;
1714 /* orig_array remains unchanged throughout the loop. If after freeing all
1715 the entries it turns out that one of the little blighters has triggered
1716 an action that has caused HvARRAY to be re-allocated, then we set
1717 array to the new HvARRAY, and try again. */
1720 /* This is the one we're going to try to empty. First time round
1721 it's the original array. (Hopefully there will only be 1 time
1723 HE ** const array = HvARRAY(hv);
1726 /* Because we have taken xhv_name out, the only allocated pointer
1727 in the aux structure that might exist is the backreference array.
1732 struct mro_meta *meta;
1733 struct xpvhv_aux *iter = HvAUX(hv);
1734 /* If there are weak references to this HV, we need to avoid
1735 freeing them up here. In particular we need to keep the AV
1736 visible as what we're deleting might well have weak references
1737 back to this HV, so the for loop below may well trigger
1738 the removal of backreferences from this array. */
1740 if (iter->xhv_backreferences) {
1741 /* So donate them to regular backref magic to keep them safe.
1742 The sv_magic will increase the reference count of the AV,
1743 so we need to drop it first. */
1744 SvREFCNT_dec(iter->xhv_backreferences);
1745 if (AvFILLp(iter->xhv_backreferences) == -1) {
1746 /* Turns out that the array is empty. Just free it. */
1747 SvREFCNT_dec(iter->xhv_backreferences);
1750 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1751 PERL_MAGIC_backref, NULL, 0);
1753 iter->xhv_backreferences = NULL;
1756 entry = iter->xhv_eiter; /* HvEITER(hv) */
1757 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1759 hv_free_ent(hv, entry);
1761 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1762 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1764 if((meta = iter->xhv_mro_meta)) {
1765 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1766 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1767 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1769 iter->xhv_mro_meta = NULL;
1772 /* There are now no allocated pointers in the aux structure. */
1774 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1775 /* What aux structure? */
1778 /* make everyone else think the array is empty, so that the destructors
1779 * called for freed entries can't recusively mess with us */
1782 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1786 /* Loop down the linked list heads */
1787 HE *entry = array[i];
1790 register HE * const oentry = entry;
1791 entry = HeNEXT(entry);
1792 hv_free_ent(hv, oentry);
1796 /* As there are no allocated pointers in the aux structure, it's now
1797 safe to free the array we just cleaned up, if it's not the one we're
1798 going to put back. */
1799 if (array != orig_array) {
1804 /* Good. No-one added anything this time round. */
1809 /* Someone attempted to iterate or set the hash name while we had
1810 the array set to 0. We'll catch backferences on the next time
1811 round the while loop. */
1812 assert(HvARRAY(hv));
1814 if (HvAUX(hv)->xhv_name) {
1815 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1819 if (--attempts == 0) {
1820 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1824 HvARRAY(hv) = orig_array;
1826 /* If the hash was actually a symbol table, put the name back. */
1828 /* We have restored the original array. If name is non-NULL, then
1829 the original array had an aux structure at the end. So this is
1831 SvFLAGS(hv) |= SVf_OOK;
1832 HvAUX(hv)->xhv_name = name;
1837 =for apidoc hv_undef
1845 Perl_hv_undef(pTHX_ HV *hv)
1848 register XPVHV* xhv;
1853 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1854 xhv = (XPVHV*)SvANY(hv);
1856 /* If it's a stash, undef the @ISA and call
1857 mro_isa_changed_in before proceeding with
1858 the rest of the destruction */
1859 if ((name = HvNAME_get(hv)) && !PL_dirty) {
1864 gvp = (GV**)hv_fetchs(hv, "ISA", FALSE);
1865 gv = gvp ? *gvp : NULL;
1866 isa = (gv && isGV_with_GP(gv)) ? GvAV(gv) : NULL;
1868 if(isa) av_undef(isa);
1869 mro_isa_changed_in(hv);
1875 hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1876 hv_name_set(hv, NULL, 0, 0);
1878 SvFLAGS(hv) &= ~SVf_OOK;
1879 Safefree(HvARRAY(hv));
1880 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1882 HvPLACEHOLDERS_set(hv, 0);
1888 static struct xpvhv_aux*
1889 S_hv_auxinit(HV *hv) {
1890 struct xpvhv_aux *iter;
1894 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1895 + sizeof(struct xpvhv_aux), char);
1897 array = (char *) HvARRAY(hv);
1898 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1899 + sizeof(struct xpvhv_aux), char);
1901 HvARRAY(hv) = (HE**) array;
1902 /* SvOOK_on(hv) attacks the IV flags. */
1903 SvFLAGS(hv) |= SVf_OOK;
1906 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1907 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1909 iter->xhv_backreferences = 0;
1910 iter->xhv_mro_meta = NULL;
1915 =for apidoc hv_iterinit
1917 Prepares a starting point to traverse a hash table. Returns the number of
1918 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1919 currently only meaningful for hashes without tie magic.
1921 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1922 hash buckets that happen to be in use. If you still need that esoteric
1923 value, you can get it through the macro C<HvFILL(tb)>.
1930 Perl_hv_iterinit(pTHX_ HV *hv)
1933 Perl_croak(aTHX_ "Bad hash");
1936 struct xpvhv_aux * const iter = HvAUX(hv);
1937 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1938 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1940 hv_free_ent(hv, entry);
1942 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1943 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1948 /* used to be xhv->xhv_fill before 5.004_65 */
1949 return HvTOTALKEYS(hv);
1953 Perl_hv_riter_p(pTHX_ HV *hv) {
1954 struct xpvhv_aux *iter;
1957 Perl_croak(aTHX_ "Bad hash");
1959 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1960 return &(iter->xhv_riter);
1964 Perl_hv_eiter_p(pTHX_ HV *hv) {
1965 struct xpvhv_aux *iter;
1968 Perl_croak(aTHX_ "Bad hash");
1970 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1971 return &(iter->xhv_eiter);
1975 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1976 struct xpvhv_aux *iter;
1979 Perl_croak(aTHX_ "Bad hash");
1987 iter = hv_auxinit(hv);
1989 iter->xhv_riter = riter;
1993 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1994 struct xpvhv_aux *iter;
1997 Perl_croak(aTHX_ "Bad hash");
2002 /* 0 is the default so don't go malloc()ing a new structure just to
2007 iter = hv_auxinit(hv);
2009 iter->xhv_eiter = eiter;
2013 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2016 struct xpvhv_aux *iter;
2019 PERL_UNUSED_ARG(flags);
2022 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2026 if (iter->xhv_name) {
2027 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2033 iter = hv_auxinit(hv);
2035 PERL_HASH(hash, name, len);
2036 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2040 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2041 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2042 PERL_UNUSED_CONTEXT;
2043 return &(iter->xhv_backreferences);
2047 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2053 av = HvAUX(hv)->xhv_backreferences;
2056 HvAUX(hv)->xhv_backreferences = 0;
2057 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
2062 hv_iternext is implemented as a macro in hv.h
2064 =for apidoc hv_iternext
2066 Returns entries from a hash iterator. See C<hv_iterinit>.
2068 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2069 iterator currently points to, without losing your place or invalidating your
2070 iterator. Note that in this case the current entry is deleted from the hash
2071 with your iterator holding the last reference to it. Your iterator is flagged
2072 to free the entry on the next call to C<hv_iternext>, so you must not discard
2073 your iterator immediately else the entry will leak - call C<hv_iternext> to
2074 trigger the resource deallocation.
2076 =for apidoc hv_iternext_flags
2078 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2079 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2080 set the placeholders keys (for restricted hashes) will be returned in addition
2081 to normal keys. By default placeholders are automatically skipped over.
2082 Currently a placeholder is implemented with a value that is
2083 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2084 restricted hashes may change, and the implementation currently is
2085 insufficiently abstracted for any change to be tidy.
2091 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2094 register XPVHV* xhv;
2098 struct xpvhv_aux *iter;
2101 Perl_croak(aTHX_ "Bad hash");
2103 xhv = (XPVHV*)SvANY(hv);
2106 /* Too many things (well, pp_each at least) merrily assume that you can
2107 call iv_iternext without calling hv_iterinit, so we'll have to deal
2113 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2114 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2115 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2116 SV * const key = sv_newmortal();
2118 sv_setsv(key, HeSVKEY_force(entry));
2119 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2125 /* one HE per MAGICAL hash */
2126 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2128 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2130 HeKEY_hek(entry) = hek;
2131 HeKLEN(entry) = HEf_SVKEY;
2133 magic_nextpack((SV*) hv,mg,key);
2135 /* force key to stay around until next time */
2136 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2137 return entry; /* beware, hent_val is not set */
2140 SvREFCNT_dec(HeVAL(entry));
2141 Safefree(HeKEY_hek(entry));
2143 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2147 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2148 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2151 /* The prime_env_iter() on VMS just loaded up new hash values
2152 * so the iteration count needs to be reset back to the beginning
2156 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2161 /* hv_iterint now ensures this. */
2162 assert (HvARRAY(hv));
2164 /* At start of hash, entry is NULL. */
2167 entry = HeNEXT(entry);
2168 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2170 * Skip past any placeholders -- don't want to include them in
2173 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2174 entry = HeNEXT(entry);
2179 /* OK. Come to the end of the current list. Grab the next one. */
2181 iter->xhv_riter++; /* HvRITER(hv)++ */
2182 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2183 /* There is no next one. End of the hash. */
2184 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2187 entry = (HvARRAY(hv))[iter->xhv_riter];
2189 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2190 /* If we have an entry, but it's a placeholder, don't count it.
2192 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2193 entry = HeNEXT(entry);
2195 /* Will loop again if this linked list starts NULL
2196 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2197 or if we run through it and find only placeholders. */
2200 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2202 hv_free_ent(hv, oldentry);
2205 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2206 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2208 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2213 =for apidoc hv_iterkey
2215 Returns the key from the current position of the hash iterator. See
2222 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2224 if (HeKLEN(entry) == HEf_SVKEY) {
2226 char * const p = SvPV(HeKEY_sv(entry), len);
2231 *retlen = HeKLEN(entry);
2232 return HeKEY(entry);
2236 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2238 =for apidoc hv_iterkeysv
2240 Returns the key as an C<SV*> from the current position of the hash
2241 iterator. The return value will always be a mortal copy of the key. Also
2248 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2250 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2254 =for apidoc hv_iterval
2256 Returns the value from the current position of the hash iterator. See
2263 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2265 if (SvRMAGICAL(hv)) {
2266 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2267 SV* const sv = sv_newmortal();
2268 if (HeKLEN(entry) == HEf_SVKEY)
2269 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2271 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2275 return HeVAL(entry);
2279 =for apidoc hv_iternextsv
2281 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2288 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2290 HE * const he = hv_iternext_flags(hv, 0);
2294 *key = hv_iterkey(he, retlen);
2295 return hv_iterval(hv, he);
2302 =for apidoc hv_magic
2304 Adds magic to a hash. See C<sv_magic>.
2309 /* possibly free a shared string if no one has access to it
2310 * len and hash must both be valid for str.
2313 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2315 unshare_hek_or_pvn (NULL, str, len, hash);
2320 Perl_unshare_hek(pTHX_ HEK *hek)
2323 unshare_hek_or_pvn(hek, NULL, 0, 0);
2326 /* possibly free a shared string if no one has access to it
2327 hek if non-NULL takes priority over the other 3, else str, len and hash
2328 are used. If so, len and hash must both be valid for str.
2331 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2334 register XPVHV* xhv;
2336 register HE **oentry;
2338 bool is_utf8 = FALSE;
2340 const char * const save = str;
2341 struct shared_he *he = NULL;
2344 /* Find the shared he which is just before us in memory. */
2345 he = (struct shared_he *)(((char *)hek)
2346 - STRUCT_OFFSET(struct shared_he,
2349 /* Assert that the caller passed us a genuine (or at least consistent)
2351 assert (he->shared_he_he.hent_hek == hek);
2354 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2355 --he->shared_he_he.he_valu.hent_refcount;
2356 UNLOCK_STRTAB_MUTEX;
2359 UNLOCK_STRTAB_MUTEX;
2361 hash = HEK_HASH(hek);
2362 } else if (len < 0) {
2363 STRLEN tmplen = -len;
2365 /* See the note in hv_fetch(). --jhi */
2366 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2369 k_flags = HVhek_UTF8;
2371 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2374 /* what follows was the moral equivalent of:
2375 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2377 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2379 xhv = (XPVHV*)SvANY(PL_strtab);
2380 /* assert(xhv_array != 0) */
2382 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2384 const HE *const he_he = &(he->shared_he_he);
2385 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2390 const int flags_masked = k_flags & HVhek_MASK;
2391 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2392 if (HeHASH(entry) != hash) /* strings can't be equal */
2394 if (HeKLEN(entry) != len)
2396 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2398 if (HeKFLAGS(entry) != flags_masked)
2405 if (--entry->he_valu.hent_refcount == 0) {
2406 *oentry = HeNEXT(entry);
2408 /* There are now no entries in our slot. */
2409 xhv->xhv_fill--; /* HvFILL(hv)-- */
2412 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2416 UNLOCK_STRTAB_MUTEX;
2417 if (!entry && ckWARN_d(WARN_INTERNAL))
2418 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2419 "Attempt to free non-existent shared string '%s'%s"
2421 hek ? HEK_KEY(hek) : str,
2422 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2423 if (k_flags & HVhek_FREEKEY)
2427 /* get a (constant) string ptr from the global string table
2428 * string will get added if it is not already there.
2429 * len and hash must both be valid for str.
2432 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2434 bool is_utf8 = FALSE;
2436 const char * const save = str;
2439 STRLEN tmplen = -len;
2441 /* See the note in hv_fetch(). --jhi */
2442 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2444 /* If we were able to downgrade here, then than means that we were passed
2445 in a key which only had chars 0-255, but was utf8 encoded. */
2448 /* If we found we were able to downgrade the string to bytes, then
2449 we should flag that it needs upgrading on keys or each. Also flag
2450 that we need share_hek_flags to free the string. */
2452 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2455 return share_hek_flags (str, len, hash, flags);
2459 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2463 const int flags_masked = flags & HVhek_MASK;
2464 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2466 /* what follows is the moral equivalent of:
2468 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2469 hv_store(PL_strtab, str, len, NULL, hash);
2471 Can't rehash the shared string table, so not sure if it's worth
2472 counting the number of entries in the linked list
2474 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2475 /* assert(xhv_array != 0) */
2477 entry = (HvARRAY(PL_strtab))[hindex];
2478 for (;entry; entry = HeNEXT(entry)) {
2479 if (HeHASH(entry) != hash) /* strings can't be equal */
2481 if (HeKLEN(entry) != len)
2483 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2485 if (HeKFLAGS(entry) != flags_masked)
2491 /* What used to be head of the list.
2492 If this is NULL, then we're the first entry for this slot, which
2493 means we need to increate fill. */
2494 struct shared_he *new_entry;
2497 HE **const head = &HvARRAY(PL_strtab)[hindex];
2498 HE *const next = *head;
2500 /* We don't actually store a HE from the arena and a regular HEK.
2501 Instead we allocate one chunk of memory big enough for both,
2502 and put the HEK straight after the HE. This way we can find the
2503 HEK directly from the HE.
2506 Newx(k, STRUCT_OFFSET(struct shared_he,
2507 shared_he_hek.hek_key[0]) + len + 2, char);
2508 new_entry = (struct shared_he *)k;
2509 entry = &(new_entry->shared_he_he);
2510 hek = &(new_entry->shared_he_hek);
2512 Copy(str, HEK_KEY(hek), len, char);
2513 HEK_KEY(hek)[len] = 0;
2515 HEK_HASH(hek) = hash;
2516 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2518 /* Still "point" to the HEK, so that other code need not know what
2520 HeKEY_hek(entry) = hek;
2521 entry->he_valu.hent_refcount = 0;
2522 HeNEXT(entry) = next;
2525 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2526 if (!next) { /* initial entry? */
2527 xhv->xhv_fill++; /* HvFILL(hv)++ */
2528 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2533 ++entry->he_valu.hent_refcount;
2534 UNLOCK_STRTAB_MUTEX;
2536 if (flags & HVhek_FREEKEY)
2539 return HeKEY_hek(entry);
2543 S_hv_magic_uvar_xkey(pTHX_ HV* hv, SV* keysv, int action)
2546 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
2547 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
2548 if (uf->uf_set == NULL) {
2549 SV* obj = mg->mg_obj;
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: