3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 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 /* We could generate this at compile time via (another) auxiliary C
45 const size_t arena_size = Perl_malloc_good_size(PERL_ARENA_SIZE);
46 HE* he = (HE*) Perl_get_arena(aTHX_ arena_size, HE_SVSLOT);
47 HE * const heend = &he[arena_size / sizeof(HE) - 1];
49 PL_body_roots[HE_SVSLOT] = he;
51 HeNEXT(he) = (HE*)(he + 1);
59 #define new_HE() (HE*)safemalloc(sizeof(HE))
60 #define del_HE(p) safefree((char*)p)
69 void ** const root = &PL_body_roots[HE_SVSLOT];
79 #define new_HE() new_he()
82 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
83 PL_body_roots[HE_SVSLOT] = p; \
91 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
93 const int flags_masked = flags & HVhek_MASK;
97 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
99 Newx(k, HEK_BASESIZE + len + 2, char);
101 Copy(str, HEK_KEY(hek), len, char);
102 HEK_KEY(hek)[len] = 0;
104 HEK_HASH(hek) = hash;
105 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
107 if (flags & HVhek_FREEKEY)
112 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
116 Perl_free_tied_hv_pool(pTHX)
119 HE *he = PL_hv_fetch_ent_mh;
122 Safefree(HeKEY_hek(he));
126 PL_hv_fetch_ent_mh = NULL;
129 #if defined(USE_ITHREADS)
131 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
133 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
135 PERL_ARGS_ASSERT_HEK_DUP;
136 PERL_UNUSED_ARG(param);
139 /* We already shared this hash key. */
140 (void)share_hek_hek(shared);
144 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
145 HEK_HASH(source), HEK_FLAGS(source));
146 ptr_table_store(PL_ptr_table, source, shared);
152 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
156 PERL_ARGS_ASSERT_HE_DUP;
160 /* look for it in the table first */
161 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
165 /* create anew and remember what it is */
167 ptr_table_store(PL_ptr_table, e, ret);
169 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
170 if (HeKLEN(e) == HEf_SVKEY) {
172 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
173 HeKEY_hek(ret) = (HEK*)k;
174 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
177 /* This is hek_dup inlined, which seems to be important for speed
179 HEK * const source = HeKEY_hek(e);
180 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
183 /* We already shared this hash key. */
184 (void)share_hek_hek(shared);
188 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
189 HEK_HASH(source), HEK_FLAGS(source));
190 ptr_table_store(PL_ptr_table, source, shared);
192 HeKEY_hek(ret) = shared;
195 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
197 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
200 #endif /* USE_ITHREADS */
203 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
206 SV * const sv = sv_newmortal();
208 PERL_ARGS_ASSERT_HV_NOTALLOWED;
210 if (!(flags & HVhek_FREEKEY)) {
211 sv_setpvn(sv, key, klen);
214 /* Need to free saved eventually assign to mortal SV */
215 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
216 sv_usepvn(sv, (char *) key, klen);
218 if (flags & HVhek_UTF8) {
221 Perl_croak(aTHX_ msg, SVfARG(sv));
224 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
230 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
231 the length of the key. The C<hash> parameter is the precomputed hash
232 value; if it is zero then Perl will compute it. The return value will be
233 NULL if the operation failed or if the value did not need to be actually
234 stored within the hash (as in the case of tied hashes). Otherwise it can
235 be dereferenced to get the original C<SV*>. Note that the caller is
236 responsible for suitably incrementing the reference count of C<val> before
237 the call, and decrementing it if the function returned NULL. Effectively
238 a successful hv_store takes ownership of one reference to C<val>. This is
239 usually what you want; a newly created SV has a reference count of one, so
240 if all your code does is create SVs then store them in a hash, hv_store
241 will own the only reference to the new SV, and your code doesn't need to do
242 anything further to tidy up. hv_store is not implemented as a call to
243 hv_store_ent, and does not create a temporary SV for the key, so if your
244 key data is not already in SV form then use hv_store in preference to
247 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
248 information on how to use this function on tied hashes.
250 =for apidoc hv_store_ent
252 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
253 parameter is the precomputed hash value; if it is zero then Perl will
254 compute it. The return value is the new hash entry so created. It will be
255 NULL if the operation failed or if the value did not need to be actually
256 stored within the hash (as in the case of tied hashes). Otherwise the
257 contents of the return value can be accessed using the C<He?> macros
258 described here. Note that the caller is responsible for suitably
259 incrementing the reference count of C<val> before the call, and
260 decrementing it if the function returned NULL. Effectively a successful
261 hv_store_ent takes ownership of one reference to C<val>. This is
262 usually what you want; a newly created SV has a reference count of one, so
263 if all your code does is create SVs then store them in a hash, hv_store
264 will own the only reference to the new SV, and your code doesn't need to do
265 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
266 unlike C<val> it does not take ownership of it, so maintaining the correct
267 reference count on C<key> is entirely the caller's responsibility. hv_store
268 is not implemented as a call to hv_store_ent, and does not create a temporary
269 SV for the key, so if your key data is not already in SV form then use
270 hv_store in preference to hv_store_ent.
272 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
273 information on how to use this function on tied hashes.
275 =for apidoc hv_exists
277 Returns a boolean indicating whether the specified hash key exists. The
278 C<klen> is the length of the key.
282 Returns the SV which corresponds to the specified key in the hash. The
283 C<klen> is the length of the key. If C<lval> is set then the fetch will be
284 part of a store. Check that the return value is non-null before
285 dereferencing it to an C<SV*>.
287 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
288 information on how to use this function on tied hashes.
290 =for apidoc hv_exists_ent
292 Returns a boolean indicating whether the specified hash key exists. C<hash>
293 can be a valid precomputed hash value, or 0 to ask for it to be
299 /* returns an HE * structure with the all fields set */
300 /* note that hent_val will be a mortal sv for MAGICAL hashes */
302 =for apidoc hv_fetch_ent
304 Returns the hash entry which corresponds to the specified key in the hash.
305 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
306 if you want the function to compute it. IF C<lval> is set then the fetch
307 will be part of a store. Make sure the return value is non-null before
308 accessing it. The return value when C<tb> is a tied hash is a pointer to a
309 static location, so be sure to make a copy of the structure if you need to
312 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
313 information on how to use this function on tied hashes.
318 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
320 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
321 const int action, SV *val, const U32 hash)
326 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
335 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
339 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
340 int flags, int action, SV *val, register U32 hash)
349 const int return_svp = action & HV_FETCH_JUST_SV;
353 if (SvTYPE(hv) == SVTYPEMASK)
356 assert(SvTYPE(hv) == SVt_PVHV);
358 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
360 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
361 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
362 if (uf->uf_set == NULL) {
363 SV* obj = mg->mg_obj;
366 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
367 ((flags & HVhek_UTF8)
371 mg->mg_obj = keysv; /* pass key */
372 uf->uf_index = action; /* pass action */
373 magic_getuvar(MUTABLE_SV(hv), mg);
374 keysv = mg->mg_obj; /* may have changed */
377 /* If the key may have changed, then we need to invalidate
378 any passed-in computed hash value. */
384 if (flags & HVhek_FREEKEY)
386 key = SvPV_const(keysv, klen);
388 is_utf8 = (SvUTF8(keysv) != 0);
390 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
393 if (action & HV_DELETE) {
394 return (void *) hv_delete_common(hv, keysv, key, klen,
395 flags | (is_utf8 ? HVhek_UTF8 : 0),
399 xhv = (XPVHV*)SvANY(hv);
401 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
402 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
403 || SvGMAGICAL((const SV *)hv))
405 /* FIXME should be able to skimp on the HE/HEK here when
406 HV_FETCH_JUST_SV is true. */
408 keysv = newSVpvn_utf8(key, klen, is_utf8);
410 keysv = newSVsv(keysv);
413 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
415 /* grab a fake HE/HEK pair from the pool or make a new one */
416 entry = PL_hv_fetch_ent_mh;
418 PL_hv_fetch_ent_mh = HeNEXT(entry);
422 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
423 HeKEY_hek(entry) = (HEK*)k;
425 HeNEXT(entry) = NULL;
426 HeSVKEY_set(entry, keysv);
428 sv_upgrade(sv, SVt_PVLV);
430 /* so we can free entry when freeing sv */
431 LvTARG(sv) = MUTABLE_SV(entry);
433 /* XXX remove at some point? */
434 if (flags & HVhek_FREEKEY)
438 return entry ? (void *) &HeVAL(entry) : NULL;
440 return (void *) entry;
442 #ifdef ENV_IS_CASELESS
443 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
445 for (i = 0; i < klen; ++i)
446 if (isLOWER(key[i])) {
447 /* Would be nice if we had a routine to do the
448 copy and upercase in a single pass through. */
449 const char * const nkey = strupr(savepvn(key,klen));
450 /* Note that this fetch is for nkey (the uppercased
451 key) whereas the store is for key (the original) */
452 void *result = hv_common(hv, NULL, nkey, klen,
453 HVhek_FREEKEY, /* free nkey */
454 0 /* non-LVAL fetch */
455 | HV_DISABLE_UVAR_XKEY
458 0 /* compute hash */);
459 if (!result && (action & HV_FETCH_LVALUE)) {
460 /* This call will free key if necessary.
461 Do it this way to encourage compiler to tail
463 result = hv_common(hv, keysv, key, klen, flags,
465 | HV_DISABLE_UVAR_XKEY
469 if (flags & HVhek_FREEKEY)
477 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
478 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
479 || SvGMAGICAL((const SV *)hv)) {
480 /* I don't understand why hv_exists_ent has svret and sv,
481 whereas hv_exists only had one. */
482 SV * const svret = sv_newmortal();
485 if (keysv || is_utf8) {
487 keysv = newSVpvn_utf8(key, klen, TRUE);
489 keysv = newSVsv(keysv);
491 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
493 mg_copy(MUTABLE_SV(hv), sv, key, klen);
495 if (flags & HVhek_FREEKEY)
497 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
498 /* This cast somewhat evil, but I'm merely using NULL/
499 not NULL to return the boolean exists.
500 And I know hv is not NULL. */
501 return SvTRUE(svret) ? (void *)hv : NULL;
503 #ifdef ENV_IS_CASELESS
504 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
505 /* XXX This code isn't UTF8 clean. */
506 char * const keysave = (char * const)key;
507 /* Will need to free this, so set FREEKEY flag. */
508 key = savepvn(key,klen);
509 key = (const char*)strupr((char*)key);
514 if (flags & HVhek_FREEKEY) {
517 flags |= HVhek_FREEKEY;
521 else if (action & HV_FETCH_ISSTORE) {
524 hv_magic_check (hv, &needs_copy, &needs_store);
526 const bool save_taint = PL_tainted;
527 if (keysv || is_utf8) {
529 keysv = newSVpvn_utf8(key, klen, TRUE);
532 PL_tainted = SvTAINTED(keysv);
533 keysv = sv_2mortal(newSVsv(keysv));
534 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
536 mg_copy(MUTABLE_SV(hv), val, key, klen);
539 TAINT_IF(save_taint);
541 if (flags & HVhek_FREEKEY)
545 #ifdef ENV_IS_CASELESS
546 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
547 /* XXX This code isn't UTF8 clean. */
548 const char *keysave = key;
549 /* Will need to free this, so set FREEKEY flag. */
550 key = savepvn(key,klen);
551 key = (const char*)strupr((char*)key);
556 if (flags & HVhek_FREEKEY) {
559 flags |= HVhek_FREEKEY;
567 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
568 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
569 || (SvRMAGICAL((const SV *)hv)
570 && mg_find((const SV *)hv, PERL_MAGIC_env))
575 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
577 HvARRAY(hv) = (HE**)array;
579 #ifdef DYNAMIC_ENV_FETCH
580 else if (action & HV_FETCH_ISEXISTS) {
581 /* for an %ENV exists, if we do an insert it's by a recursive
582 store call, so avoid creating HvARRAY(hv) right now. */
586 /* XXX remove at some point? */
587 if (flags & HVhek_FREEKEY)
595 char * const keysave = (char *)key;
596 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
600 flags &= ~HVhek_UTF8;
601 if (key != keysave) {
602 if (flags & HVhek_FREEKEY)
604 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
609 PERL_HASH_INTERNAL(hash, key, klen);
610 /* We don't have a pointer to the hv, so we have to replicate the
611 flag into every HEK, so that hv_iterkeysv can see it. */
612 /* And yes, you do need this even though you are not "storing" because
613 you can flip the flags below if doing an lval lookup. (And that
614 was put in to give the semantics Andreas was expecting.) */
615 flags |= HVhek_REHASH;
617 if (keysv && (SvIsCOW_shared_hash(keysv))) {
618 hash = SvSHARED_HASH(keysv);
620 PERL_HASH(hash, key, klen);
624 masked_flags = (flags & HVhek_MASK);
626 #ifdef DYNAMIC_ENV_FETCH
627 if (!HvARRAY(hv)) entry = NULL;
631 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
633 for (; entry; entry = HeNEXT(entry)) {
634 if (HeHASH(entry) != hash) /* strings can't be equal */
636 if (HeKLEN(entry) != (I32)klen)
638 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
640 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
643 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
644 if (HeKFLAGS(entry) != masked_flags) {
645 /* We match if HVhek_UTF8 bit in our flags and hash key's
646 match. But if entry was set previously with HVhek_WASUTF8
647 and key now doesn't (or vice versa) then we should change
648 the key's flag, as this is assignment. */
649 if (HvSHAREKEYS(hv)) {
650 /* Need to swap the key we have for a key with the flags we
651 need. As keys are shared we can't just write to the
652 flag, so we share the new one, unshare the old one. */
653 HEK * const new_hek = share_hek_flags(key, klen, hash,
655 unshare_hek (HeKEY_hek(entry));
656 HeKEY_hek(entry) = new_hek;
658 else if (hv == PL_strtab) {
659 /* PL_strtab is usually the only hash without HvSHAREKEYS,
660 so putting this test here is cheap */
661 if (flags & HVhek_FREEKEY)
663 Perl_croak(aTHX_ S_strtab_error,
664 action & HV_FETCH_LVALUE ? "fetch" : "store");
667 HeKFLAGS(entry) = masked_flags;
668 if (masked_flags & HVhek_ENABLEHVKFLAGS)
671 if (HeVAL(entry) == &PL_sv_placeholder) {
672 /* yes, can store into placeholder slot */
673 if (action & HV_FETCH_LVALUE) {
675 /* This preserves behaviour with the old hv_fetch
676 implementation which at this point would bail out
677 with a break; (at "if we find a placeholder, we
678 pretend we haven't found anything")
680 That break mean that if a placeholder were found, it
681 caused a call into hv_store, which in turn would
682 check magic, and if there is no magic end up pretty
683 much back at this point (in hv_store's code). */
686 /* LVAL fetch which actaully needs a store. */
688 HvPLACEHOLDERS(hv)--;
691 if (val != &PL_sv_placeholder)
692 HvPLACEHOLDERS(hv)--;
695 } else if (action & HV_FETCH_ISSTORE) {
696 SvREFCNT_dec(HeVAL(entry));
699 } else if (HeVAL(entry) == &PL_sv_placeholder) {
700 /* if we find a placeholder, we pretend we haven't found
704 if (flags & HVhek_FREEKEY)
707 return entry ? (void *) &HeVAL(entry) : NULL;
711 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
712 if (!(action & HV_FETCH_ISSTORE)
713 && SvRMAGICAL((const SV *)hv)
714 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
716 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
718 sv = newSVpvn(env,len);
720 return hv_common(hv, keysv, key, klen, flags,
721 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
727 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
728 hv_notallowed(flags, key, klen,
729 "Attempt to access disallowed key '%"SVf"' in"
730 " a restricted hash");
732 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
733 /* Not doing some form of store, so return failure. */
734 if (flags & HVhek_FREEKEY)
738 if (action & HV_FETCH_LVALUE) {
741 /* At this point the old hv_fetch code would call to hv_store,
742 which in turn might do some tied magic. So we need to make that
743 magic check happen. */
744 /* gonna assign to this, so it better be there */
745 /* If a fetch-as-store fails on the fetch, then the action is to
746 recurse once into "hv_store". If we didn't do this, then that
747 recursive call would call the key conversion routine again.
748 However, as we replace the original key with the converted
749 key, this would result in a double conversion, which would show
750 up as a bug if the conversion routine is not idempotent. */
751 return hv_common(hv, keysv, key, klen, flags,
752 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
754 /* XXX Surely that could leak if the fetch-was-store fails?
755 Just like the hv_fetch. */
759 /* Welcome to hv_store... */
762 /* Not sure if we can get here. I think the only case of oentry being
763 NULL is for %ENV with dynamic env fetch. But that should disappear
764 with magic in the previous code. */
767 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
769 HvARRAY(hv) = (HE**)array;
772 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
775 /* share_hek_flags will do the free for us. This might be considered
778 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
779 else if (hv == PL_strtab) {
780 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
781 this test here is cheap */
782 if (flags & HVhek_FREEKEY)
784 Perl_croak(aTHX_ S_strtab_error,
785 action & HV_FETCH_LVALUE ? "fetch" : "store");
787 else /* gotta do the real thing */
788 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
790 HeNEXT(entry) = *oentry;
793 if (val == &PL_sv_placeholder)
794 HvPLACEHOLDERS(hv)++;
795 if (masked_flags & HVhek_ENABLEHVKFLAGS)
799 const HE *counter = HeNEXT(entry);
801 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
802 if (!counter) { /* initial entry? */
803 xhv->xhv_fill++; /* HvFILL(hv)++ */
804 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
806 } else if(!HvREHASH(hv)) {
809 while ((counter = HeNEXT(counter)))
812 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
813 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
814 bucket splits on a rehashed hash, as we're not going to
815 split it again, and if someone is lucky (evil) enough to
816 get all the keys in one list they could exhaust our memory
817 as we repeatedly double the number of buckets on every
818 entry. Linear search feels a less worse thing to do. */
825 return entry ? (void *) &HeVAL(entry) : NULL;
827 return (void *) entry;
831 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
833 const MAGIC *mg = SvMAGIC(hv);
835 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
840 if (isUPPER(mg->mg_type)) {
842 if (mg->mg_type == PERL_MAGIC_tied) {
843 *needs_store = FALSE;
844 return; /* We've set all there is to set. */
847 mg = mg->mg_moremagic;
852 =for apidoc hv_scalar
854 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
860 Perl_hv_scalar(pTHX_ HV *hv)
864 PERL_ARGS_ASSERT_HV_SCALAR;
866 if (SvRMAGICAL(hv)) {
867 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
869 return magic_scalarpack(hv, mg);
873 if (HvFILL((const HV *)hv))
874 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
875 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
883 =for apidoc hv_delete
885 Deletes a key/value pair in the hash. The value SV is removed from the
886 hash and returned to the caller. The C<klen> is the length of the key.
887 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
890 =for apidoc hv_delete_ent
892 Deletes a key/value pair in the hash. The value SV is removed from the
893 hash and returned to the caller. The C<flags> value will normally be zero;
894 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
895 precomputed hash value, or 0 to ask for it to be computed.
901 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
902 int k_flags, I32 d_flags, U32 hash)
907 register HE **oentry;
908 HE *const *first_entry;
909 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
912 if (SvRMAGICAL(hv)) {
915 hv_magic_check (hv, &needs_copy, &needs_store);
919 entry = (HE *) hv_common(hv, keysv, key, klen,
920 k_flags & ~HVhek_FREEKEY,
921 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
923 sv = entry ? HeVAL(entry) : NULL;
929 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
930 /* No longer an element */
931 sv_unmagic(sv, PERL_MAGIC_tiedelem);
934 return NULL; /* element cannot be deleted */
936 #ifdef ENV_IS_CASELESS
937 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
938 /* XXX This code isn't UTF8 clean. */
939 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
940 if (k_flags & HVhek_FREEKEY) {
943 key = strupr(SvPVX(keysv));
952 xhv = (XPVHV*)SvANY(hv);
957 const char * const keysave = key;
958 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
961 k_flags |= HVhek_UTF8;
963 k_flags &= ~HVhek_UTF8;
964 if (key != keysave) {
965 if (k_flags & HVhek_FREEKEY) {
966 /* This shouldn't happen if our caller does what we expect,
967 but strictly the API allows it. */
970 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
972 HvHASKFLAGS_on(MUTABLE_SV(hv));
976 PERL_HASH_INTERNAL(hash, key, klen);
978 if (keysv && (SvIsCOW_shared_hash(keysv))) {
979 hash = SvSHARED_HASH(keysv);
981 PERL_HASH(hash, key, klen);
985 masked_flags = (k_flags & HVhek_MASK);
987 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
989 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
991 if (HeHASH(entry) != hash) /* strings can't be equal */
993 if (HeKLEN(entry) != (I32)klen)
995 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
997 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1000 if (hv == PL_strtab) {
1001 if (k_flags & HVhek_FREEKEY)
1003 Perl_croak(aTHX_ S_strtab_error, "delete");
1006 /* if placeholder is here, it's already been deleted.... */
1007 if (HeVAL(entry) == &PL_sv_placeholder) {
1008 if (k_flags & HVhek_FREEKEY)
1012 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1013 hv_notallowed(k_flags, key, klen,
1014 "Attempt to delete readonly key '%"SVf"' from"
1015 " a restricted hash");
1017 if (k_flags & HVhek_FREEKEY)
1020 if (d_flags & G_DISCARD)
1023 sv = sv_2mortal(HeVAL(entry));
1024 HeVAL(entry) = &PL_sv_placeholder;
1028 * If a restricted hash, rather than really deleting the entry, put
1029 * a placeholder there. This marks the key as being "approved", so
1030 * we can still access via not-really-existing key without raising
1033 if (SvREADONLY(hv)) {
1034 SvREFCNT_dec(HeVAL(entry));
1035 HeVAL(entry) = &PL_sv_placeholder;
1036 /* We'll be saving this slot, so the number of allocated keys
1037 * doesn't go down, but the number placeholders goes up */
1038 HvPLACEHOLDERS(hv)++;
1040 *oentry = HeNEXT(entry);
1042 xhv->xhv_fill--; /* HvFILL(hv)-- */
1044 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1047 hv_free_ent(hv, entry);
1048 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1049 if (xhv->xhv_keys == 0)
1050 HvHASKFLAGS_off(hv);
1054 if (SvREADONLY(hv)) {
1055 hv_notallowed(k_flags, key, klen,
1056 "Attempt to delete disallowed key '%"SVf"' from"
1057 " a restricted hash");
1060 if (k_flags & HVhek_FREEKEY)
1066 S_hsplit(pTHX_ HV *hv)
1069 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1070 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1071 register I32 newsize = oldsize * 2;
1073 char *a = (char*) HvARRAY(hv);
1075 register HE **oentry;
1076 int longest_chain = 0;
1079 PERL_ARGS_ASSERT_HSPLIT;
1081 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1082 (void*)hv, (int) oldsize);*/
1084 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1085 /* Can make this clear any placeholders first for non-restricted hashes,
1086 even though Storable rebuilds restricted hashes by putting in all the
1087 placeholders (first) before turning on the readonly flag, because
1088 Storable always pre-splits the hash. */
1089 hv_clear_placeholders(hv);
1093 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1094 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1095 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1101 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1104 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1105 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1110 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1112 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1114 if (oldsize >= 64) {
1115 offer_nice_chunk(HvARRAY(hv),
1116 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1117 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1120 Safefree(HvARRAY(hv));
1124 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1125 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1126 HvARRAY(hv) = (HE**) a;
1129 for (i=0; i<oldsize; i++,aep++) {
1130 int left_length = 0;
1131 int right_length = 0;
1135 if (!*aep) /* non-existent */
1138 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1139 if ((HeHASH(entry) & newsize) != (U32)i) {
1140 *oentry = HeNEXT(entry);
1141 HeNEXT(entry) = *bep;
1143 xhv->xhv_fill++; /* HvFILL(hv)++ */
1149 oentry = &HeNEXT(entry);
1153 if (!*aep) /* everything moved */
1154 xhv->xhv_fill--; /* HvFILL(hv)-- */
1155 /* I think we don't actually need to keep track of the longest length,
1156 merely flag if anything is too long. But for the moment while
1157 developing this code I'll track it. */
1158 if (left_length > longest_chain)
1159 longest_chain = left_length;
1160 if (right_length > longest_chain)
1161 longest_chain = right_length;
1165 /* Pick your policy for "hashing isn't working" here: */
1166 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1171 if (hv == PL_strtab) {
1172 /* Urg. Someone is doing something nasty to the string table.
1177 /* Awooga. Awooga. Pathological data. */
1178 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1179 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1182 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1183 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1185 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1188 was_shared = HvSHAREKEYS(hv);
1191 HvSHAREKEYS_off(hv);
1196 for (i=0; i<newsize; i++,aep++) {
1197 register HE *entry = *aep;
1199 /* We're going to trash this HE's next pointer when we chain it
1200 into the new hash below, so store where we go next. */
1201 HE * const next = HeNEXT(entry);
1206 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1211 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1212 hash, HeKFLAGS(entry));
1213 unshare_hek (HeKEY_hek(entry));
1214 HeKEY_hek(entry) = new_hek;
1216 /* Not shared, so simply write the new hash in. */
1217 HeHASH(entry) = hash;
1219 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1220 HEK_REHASH_on(HeKEY_hek(entry));
1221 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1223 /* Copy oentry to the correct new chain. */
1224 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1226 xhv->xhv_fill++; /* HvFILL(hv)++ */
1227 HeNEXT(entry) = *bep;
1233 Safefree (HvARRAY(hv));
1234 HvARRAY(hv) = (HE **)a;
1238 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1241 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1242 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1243 register I32 newsize;
1248 register HE **oentry;
1250 PERL_ARGS_ASSERT_HV_KSPLIT;
1252 newsize = (I32) newmax; /* possible truncation here */
1253 if (newsize != newmax || newmax <= oldsize)
1255 while ((newsize & (1 + ~newsize)) != newsize) {
1256 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1258 if (newsize < newmax)
1260 if (newsize < newmax)
1261 return; /* overflow detection */
1263 a = (char *) HvARRAY(hv);
1266 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1267 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1268 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1274 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1277 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1278 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1283 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1285 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1287 if (oldsize >= 64) {
1288 offer_nice_chunk(HvARRAY(hv),
1289 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1290 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1293 Safefree(HvARRAY(hv));
1296 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1299 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1301 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1302 HvARRAY(hv) = (HE **) a;
1303 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1307 for (i=0; i<oldsize; i++,aep++) {
1308 if (!*aep) /* non-existent */
1310 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1311 register I32 j = (HeHASH(entry) & newsize);
1315 *oentry = HeNEXT(entry);
1316 if (!(HeNEXT(entry) = aep[j]))
1317 xhv->xhv_fill++; /* HvFILL(hv)++ */
1322 oentry = &HeNEXT(entry);
1324 if (!*aep) /* everything moved */
1325 xhv->xhv_fill--; /* HvFILL(hv)-- */
1330 Perl_newHVhv(pTHX_ HV *ohv)
1332 HV * const hv = newHV();
1333 STRLEN hv_max, hv_fill;
1335 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1337 hv_max = HvMAX(ohv);
1339 if (!SvMAGICAL((const SV *)ohv)) {
1340 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1342 const bool shared = !!HvSHAREKEYS(ohv);
1343 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1345 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1348 /* In each bucket... */
1349 for (i = 0; i <= hv_max; i++) {
1351 HE *oent = oents[i];
1358 /* Copy the linked list of entries. */
1359 for (; oent; oent = HeNEXT(oent)) {
1360 const U32 hash = HeHASH(oent);
1361 const char * const key = HeKEY(oent);
1362 const STRLEN len = HeKLEN(oent);
1363 const int flags = HeKFLAGS(oent);
1364 HE * const ent = new_HE();
1366 HeVAL(ent) = newSVsv(HeVAL(oent));
1368 = shared ? share_hek_flags(key, len, hash, flags)
1369 : save_hek_flags(key, len, hash, flags);
1380 HvFILL(hv) = hv_fill;
1381 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1385 /* Iterate over ohv, copying keys and values one at a time. */
1387 const I32 riter = HvRITER_get(ohv);
1388 HE * const eiter = HvEITER_get(ohv);
1390 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1391 while (hv_max && hv_max + 1 >= hv_fill * 2)
1392 hv_max = hv_max / 2;
1396 while ((entry = hv_iternext_flags(ohv, 0))) {
1397 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1398 newSVsv(HeVAL(entry)), HeHASH(entry),
1401 HvRITER_set(ohv, riter);
1402 HvEITER_set(ohv, eiter);
1408 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1409 magic stays on it. */
1411 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1413 HV * const hv = newHV();
1416 if (ohv && (hv_fill = HvFILL(ohv))) {
1417 STRLEN hv_max = HvMAX(ohv);
1419 const I32 riter = HvRITER_get(ohv);
1420 HE * const eiter = HvEITER_get(ohv);
1422 while (hv_max && hv_max + 1 >= hv_fill * 2)
1423 hv_max = hv_max / 2;
1427 while ((entry = hv_iternext_flags(ohv, 0))) {
1428 SV *const sv = newSVsv(HeVAL(entry));
1429 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1430 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1431 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1432 sv, HeHASH(entry), HeKFLAGS(entry));
1434 HvRITER_set(ohv, riter);
1435 HvEITER_set(ohv, eiter);
1437 hv_magic(hv, NULL, PERL_MAGIC_hints);
1442 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1447 PERL_ARGS_ASSERT_HV_FREE_ENT;
1452 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1453 mro_method_changed_in(hv); /* deletion of method from stash */
1455 if (HeKLEN(entry) == HEf_SVKEY) {
1456 SvREFCNT_dec(HeKEY_sv(entry));
1457 Safefree(HeKEY_hek(entry));
1459 else if (HvSHAREKEYS(hv))
1460 unshare_hek(HeKEY_hek(entry));
1462 Safefree(HeKEY_hek(entry));
1467 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1471 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1475 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1476 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1477 if (HeKLEN(entry) == HEf_SVKEY) {
1478 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1480 hv_free_ent(hv, entry);
1484 =for apidoc hv_clear
1486 Clears a hash, making it empty.
1492 Perl_hv_clear(pTHX_ HV *hv)
1495 register XPVHV* xhv;
1499 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1501 xhv = (XPVHV*)SvANY(hv);
1503 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1504 /* restricted hash: convert all keys to placeholders */
1506 for (i = 0; i <= xhv->xhv_max; i++) {
1507 HE *entry = (HvARRAY(hv))[i];
1508 for (; entry; entry = HeNEXT(entry)) {
1509 /* not already placeholder */
1510 if (HeVAL(entry) != &PL_sv_placeholder) {
1511 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1512 SV* const keysv = hv_iterkeysv(entry);
1514 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1517 SvREFCNT_dec(HeVAL(entry));
1518 HeVAL(entry) = &PL_sv_placeholder;
1519 HvPLACEHOLDERS(hv)++;
1527 HvPLACEHOLDERS_set(hv, 0);
1529 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1532 mg_clear(MUTABLE_SV(hv));
1534 HvHASKFLAGS_off(hv);
1539 mro_isa_changed_in(hv);
1540 HvEITER_set(hv, NULL);
1545 =for apidoc hv_clear_placeholders
1547 Clears any placeholders from a hash. If a restricted hash has any of its keys
1548 marked as readonly and the key is subsequently deleted, the key is not actually
1549 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1550 it so it will be ignored by future operations such as iterating over the hash,
1551 but will still allow the hash to have a value reassigned to the key at some
1552 future point. This function clears any such placeholder keys from the hash.
1553 See Hash::Util::lock_keys() for an example of its use.
1559 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1562 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1564 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1567 clear_placeholders(hv, items);
1571 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1576 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1583 /* Loop down the linked list heads */
1585 HE **oentry = &(HvARRAY(hv))[i];
1588 while ((entry = *oentry)) {
1589 if (HeVAL(entry) == &PL_sv_placeholder) {
1590 *oentry = HeNEXT(entry);
1591 if (first && !*oentry)
1592 HvFILL(hv)--; /* This linked list is now empty. */
1593 if (entry == HvEITER_get(hv))
1596 hv_free_ent(hv, entry);
1600 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1601 if (HvKEYS(hv) == 0)
1602 HvHASKFLAGS_off(hv);
1603 HvPLACEHOLDERS_set(hv, 0);
1607 oentry = &HeNEXT(entry);
1612 /* You can't get here, hence assertion should always fail. */
1613 assert (items == 0);
1618 S_hfreeentries(pTHX_ HV *hv)
1620 /* This is the array that we're going to restore */
1621 HE **const orig_array = HvARRAY(hv);
1625 PERL_ARGS_ASSERT_HFREEENTRIES;
1631 /* If the hash is actually a symbol table with a name, look after the
1633 struct xpvhv_aux *iter = HvAUX(hv);
1635 name = iter->xhv_name;
1636 iter->xhv_name = NULL;
1641 /* orig_array remains unchanged throughout the loop. If after freeing all
1642 the entries it turns out that one of the little blighters has triggered
1643 an action that has caused HvARRAY to be re-allocated, then we set
1644 array to the new HvARRAY, and try again. */
1647 /* This is the one we're going to try to empty. First time round
1648 it's the original array. (Hopefully there will only be 1 time
1650 HE ** const array = HvARRAY(hv);
1653 /* Because we have taken xhv_name out, the only allocated pointer
1654 in the aux structure that might exist is the backreference array.
1659 struct mro_meta *meta;
1660 struct xpvhv_aux *iter = HvAUX(hv);
1661 /* If there are weak references to this HV, we need to avoid
1662 freeing them up here. In particular we need to keep the AV
1663 visible as what we're deleting might well have weak references
1664 back to this HV, so the for loop below may well trigger
1665 the removal of backreferences from this array. */
1667 if (iter->xhv_backreferences) {
1668 /* So donate them to regular backref magic to keep them safe.
1669 The sv_magic will increase the reference count of the AV,
1670 so we need to drop it first. */
1671 SvREFCNT_dec(iter->xhv_backreferences);
1672 if (AvFILLp(iter->xhv_backreferences) == -1) {
1673 /* Turns out that the array is empty. Just free it. */
1674 SvREFCNT_dec(iter->xhv_backreferences);
1677 sv_magic(MUTABLE_SV(hv),
1678 MUTABLE_SV(iter->xhv_backreferences),
1679 PERL_MAGIC_backref, NULL, 0);
1681 iter->xhv_backreferences = NULL;
1684 entry = iter->xhv_eiter; /* HvEITER(hv) */
1685 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1687 hv_free_ent(hv, entry);
1689 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1690 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1692 if((meta = iter->xhv_mro_meta)) {
1693 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1694 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1695 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1696 SvREFCNT_dec(meta->isa);
1698 iter->xhv_mro_meta = NULL;
1701 /* There are now no allocated pointers in the aux structure. */
1703 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1704 /* What aux structure? */
1707 /* make everyone else think the array is empty, so that the destructors
1708 * called for freed entries can't recusively mess with us */
1711 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1715 /* Loop down the linked list heads */
1716 HE *entry = array[i];
1719 register HE * const oentry = entry;
1720 entry = HeNEXT(entry);
1721 hv_free_ent(hv, oentry);
1725 /* As there are no allocated pointers in the aux structure, it's now
1726 safe to free the array we just cleaned up, if it's not the one we're
1727 going to put back. */
1728 if (array != orig_array) {
1733 /* Good. No-one added anything this time round. */
1738 /* Someone attempted to iterate or set the hash name while we had
1739 the array set to 0. We'll catch backferences on the next time
1740 round the while loop. */
1741 assert(HvARRAY(hv));
1743 if (HvAUX(hv)->xhv_name) {
1744 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1748 if (--attempts == 0) {
1749 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1753 HvARRAY(hv) = orig_array;
1755 /* If the hash was actually a symbol table, put the name back. */
1757 /* We have restored the original array. If name is non-NULL, then
1758 the original array had an aux structure at the end. So this is
1760 SvFLAGS(hv) |= SVf_OOK;
1761 HvAUX(hv)->xhv_name = name;
1766 =for apidoc hv_undef
1774 Perl_hv_undef(pTHX_ HV *hv)
1777 register XPVHV* xhv;
1782 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1783 xhv = (XPVHV*)SvANY(hv);
1785 if ((name = HvNAME_get(hv)) && !PL_dirty)
1786 mro_isa_changed_in(hv);
1791 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1792 hv_name_set(hv, NULL, 0, 0);
1794 SvFLAGS(hv) &= ~SVf_OOK;
1795 Safefree(HvARRAY(hv));
1796 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1798 HvPLACEHOLDERS_set(hv, 0);
1801 mg_clear(MUTABLE_SV(hv));
1804 static struct xpvhv_aux*
1805 S_hv_auxinit(HV *hv) {
1806 struct xpvhv_aux *iter;
1809 PERL_ARGS_ASSERT_HV_AUXINIT;
1812 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1813 + sizeof(struct xpvhv_aux), char);
1815 array = (char *) HvARRAY(hv);
1816 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1817 + sizeof(struct xpvhv_aux), char);
1819 HvARRAY(hv) = (HE**) array;
1820 /* SvOOK_on(hv) attacks the IV flags. */
1821 SvFLAGS(hv) |= SVf_OOK;
1824 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1825 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1827 iter->xhv_backreferences = 0;
1828 iter->xhv_mro_meta = NULL;
1833 =for apidoc hv_iterinit
1835 Prepares a starting point to traverse a hash table. Returns the number of
1836 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1837 currently only meaningful for hashes without tie magic.
1839 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1840 hash buckets that happen to be in use. If you still need that esoteric
1841 value, you can get it through the macro C<HvFILL(tb)>.
1848 Perl_hv_iterinit(pTHX_ HV *hv)
1850 PERL_ARGS_ASSERT_HV_ITERINIT;
1852 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1855 Perl_croak(aTHX_ "Bad hash");
1858 struct xpvhv_aux * const iter = HvAUX(hv);
1859 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1860 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1862 hv_free_ent(hv, entry);
1864 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1865 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1870 /* used to be xhv->xhv_fill before 5.004_65 */
1871 return HvTOTALKEYS(hv);
1875 Perl_hv_riter_p(pTHX_ HV *hv) {
1876 struct xpvhv_aux *iter;
1878 PERL_ARGS_ASSERT_HV_RITER_P;
1881 Perl_croak(aTHX_ "Bad hash");
1883 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1884 return &(iter->xhv_riter);
1888 Perl_hv_eiter_p(pTHX_ HV *hv) {
1889 struct xpvhv_aux *iter;
1891 PERL_ARGS_ASSERT_HV_EITER_P;
1894 Perl_croak(aTHX_ "Bad hash");
1896 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1897 return &(iter->xhv_eiter);
1901 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1902 struct xpvhv_aux *iter;
1904 PERL_ARGS_ASSERT_HV_RITER_SET;
1907 Perl_croak(aTHX_ "Bad hash");
1915 iter = hv_auxinit(hv);
1917 iter->xhv_riter = riter;
1921 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1922 struct xpvhv_aux *iter;
1924 PERL_ARGS_ASSERT_HV_EITER_SET;
1927 Perl_croak(aTHX_ "Bad hash");
1932 /* 0 is the default so don't go malloc()ing a new structure just to
1937 iter = hv_auxinit(hv);
1939 iter->xhv_eiter = eiter;
1943 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1946 struct xpvhv_aux *iter;
1949 PERL_ARGS_ASSERT_HV_NAME_SET;
1950 PERL_UNUSED_ARG(flags);
1953 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1957 if (iter->xhv_name) {
1958 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1964 iter = hv_auxinit(hv);
1966 PERL_HASH(hash, name, len);
1967 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1971 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1972 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1974 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
1975 PERL_UNUSED_CONTEXT;
1977 return &(iter->xhv_backreferences);
1981 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
1984 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
1989 av = HvAUX(hv)->xhv_backreferences;
1992 HvAUX(hv)->xhv_backreferences = 0;
1993 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
1999 hv_iternext is implemented as a macro in hv.h
2001 =for apidoc hv_iternext
2003 Returns entries from a hash iterator. See C<hv_iterinit>.
2005 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2006 iterator currently points to, without losing your place or invalidating your
2007 iterator. Note that in this case the current entry is deleted from the hash
2008 with your iterator holding the last reference to it. Your iterator is flagged
2009 to free the entry on the next call to C<hv_iternext>, so you must not discard
2010 your iterator immediately else the entry will leak - call C<hv_iternext> to
2011 trigger the resource deallocation.
2013 =for apidoc hv_iternext_flags
2015 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2016 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2017 set the placeholders keys (for restricted hashes) will be returned in addition
2018 to normal keys. By default placeholders are automatically skipped over.
2019 Currently a placeholder is implemented with a value that is
2020 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2021 restricted hashes may change, and the implementation currently is
2022 insufficiently abstracted for any change to be tidy.
2028 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2031 register XPVHV* xhv;
2035 struct xpvhv_aux *iter;
2037 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2040 Perl_croak(aTHX_ "Bad hash");
2042 xhv = (XPVHV*)SvANY(hv);
2045 /* Too many things (well, pp_each at least) merrily assume that you can
2046 call iv_iternext without calling hv_iterinit, so we'll have to deal
2052 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2053 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2054 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2055 SV * const key = sv_newmortal();
2057 sv_setsv(key, HeSVKEY_force(entry));
2058 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2064 /* one HE per MAGICAL hash */
2065 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2067 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2069 HeKEY_hek(entry) = hek;
2070 HeKLEN(entry) = HEf_SVKEY;
2072 magic_nextpack(MUTABLE_SV(hv),mg,key);
2074 /* force key to stay around until next time */
2075 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2076 return entry; /* beware, hent_val is not set */
2079 SvREFCNT_dec(HeVAL(entry));
2080 Safefree(HeKEY_hek(entry));
2082 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2086 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2087 if (!entry && SvRMAGICAL((const SV *)hv)
2088 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2091 /* The prime_env_iter() on VMS just loaded up new hash values
2092 * so the iteration count needs to be reset back to the beginning
2096 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2101 /* hv_iterint now ensures this. */
2102 assert (HvARRAY(hv));
2104 /* At start of hash, entry is NULL. */
2107 entry = HeNEXT(entry);
2108 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2110 * Skip past any placeholders -- don't want to include them in
2113 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2114 entry = HeNEXT(entry);
2119 /* OK. Come to the end of the current list. Grab the next one. */
2121 iter->xhv_riter++; /* HvRITER(hv)++ */
2122 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2123 /* There is no next one. End of the hash. */
2124 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2127 entry = (HvARRAY(hv))[iter->xhv_riter];
2129 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2130 /* If we have an entry, but it's a placeholder, don't count it.
2132 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2133 entry = HeNEXT(entry);
2135 /* Will loop again if this linked list starts NULL
2136 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2137 or if we run through it and find only placeholders. */
2140 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2142 hv_free_ent(hv, oldentry);
2145 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2146 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2148 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2153 =for apidoc hv_iterkey
2155 Returns the key from the current position of the hash iterator. See
2162 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2164 PERL_ARGS_ASSERT_HV_ITERKEY;
2166 if (HeKLEN(entry) == HEf_SVKEY) {
2168 char * const p = SvPV(HeKEY_sv(entry), len);
2173 *retlen = HeKLEN(entry);
2174 return HeKEY(entry);
2178 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2180 =for apidoc hv_iterkeysv
2182 Returns the key as an C<SV*> from the current position of the hash
2183 iterator. The return value will always be a mortal copy of the key. Also
2190 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2192 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2194 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2198 =for apidoc hv_iterval
2200 Returns the value from the current position of the hash iterator. See
2207 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2209 PERL_ARGS_ASSERT_HV_ITERVAL;
2211 if (SvRMAGICAL(hv)) {
2212 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2213 SV* const sv = sv_newmortal();
2214 if (HeKLEN(entry) == HEf_SVKEY)
2215 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2217 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2221 return HeVAL(entry);
2225 =for apidoc hv_iternextsv
2227 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2234 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2236 HE * const he = hv_iternext_flags(hv, 0);
2238 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2242 *key = hv_iterkey(he, retlen);
2243 return hv_iterval(hv, he);
2250 =for apidoc hv_magic
2252 Adds magic to a hash. See C<sv_magic>.
2257 /* possibly free a shared string if no one has access to it
2258 * len and hash must both be valid for str.
2261 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2263 unshare_hek_or_pvn (NULL, str, len, hash);
2268 Perl_unshare_hek(pTHX_ HEK *hek)
2271 unshare_hek_or_pvn(hek, NULL, 0, 0);
2274 /* possibly free a shared string if no one has access to it
2275 hek if non-NULL takes priority over the other 3, else str, len and hash
2276 are used. If so, len and hash must both be valid for str.
2279 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2282 register XPVHV* xhv;
2284 register HE **oentry;
2286 bool is_utf8 = FALSE;
2288 const char * const save = str;
2289 struct shared_he *he = NULL;
2292 /* Find the shared he which is just before us in memory. */
2293 he = (struct shared_he *)(((char *)hek)
2294 - STRUCT_OFFSET(struct shared_he,
2297 /* Assert that the caller passed us a genuine (or at least consistent)
2299 assert (he->shared_he_he.hent_hek == hek);
2302 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2303 --he->shared_he_he.he_valu.hent_refcount;
2304 UNLOCK_STRTAB_MUTEX;
2307 UNLOCK_STRTAB_MUTEX;
2309 hash = HEK_HASH(hek);
2310 } else if (len < 0) {
2311 STRLEN tmplen = -len;
2313 /* See the note in hv_fetch(). --jhi */
2314 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2317 k_flags = HVhek_UTF8;
2319 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2322 /* what follows was the moral equivalent of:
2323 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2325 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2327 xhv = (XPVHV*)SvANY(PL_strtab);
2328 /* assert(xhv_array != 0) */
2330 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2332 const HE *const he_he = &(he->shared_he_he);
2333 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2338 const int flags_masked = k_flags & HVhek_MASK;
2339 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2340 if (HeHASH(entry) != hash) /* strings can't be equal */
2342 if (HeKLEN(entry) != len)
2344 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2346 if (HeKFLAGS(entry) != flags_masked)
2353 if (--entry->he_valu.hent_refcount == 0) {
2354 *oentry = HeNEXT(entry);
2356 /* There are now no entries in our slot. */
2357 xhv->xhv_fill--; /* HvFILL(hv)-- */
2360 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2364 UNLOCK_STRTAB_MUTEX;
2365 if (!entry && ckWARN_d(WARN_INTERNAL))
2366 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2367 "Attempt to free non-existent shared string '%s'%s"
2369 hek ? HEK_KEY(hek) : str,
2370 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2371 if (k_flags & HVhek_FREEKEY)
2375 /* get a (constant) string ptr from the global string table
2376 * string will get added if it is not already there.
2377 * len and hash must both be valid for str.
2380 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2382 bool is_utf8 = FALSE;
2384 const char * const save = str;
2386 PERL_ARGS_ASSERT_SHARE_HEK;
2389 STRLEN tmplen = -len;
2391 /* See the note in hv_fetch(). --jhi */
2392 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2394 /* If we were able to downgrade here, then than means that we were passed
2395 in a key which only had chars 0-255, but was utf8 encoded. */
2398 /* If we found we were able to downgrade the string to bytes, then
2399 we should flag that it needs upgrading on keys or each. Also flag
2400 that we need share_hek_flags to free the string. */
2402 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2405 return share_hek_flags (str, len, hash, flags);
2409 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2413 const int flags_masked = flags & HVhek_MASK;
2414 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2415 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2417 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2419 /* what follows is the moral equivalent of:
2421 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2422 hv_store(PL_strtab, str, len, NULL, hash);
2424 Can't rehash the shared string table, so not sure if it's worth
2425 counting the number of entries in the linked list
2428 /* assert(xhv_array != 0) */
2430 entry = (HvARRAY(PL_strtab))[hindex];
2431 for (;entry; entry = HeNEXT(entry)) {
2432 if (HeHASH(entry) != hash) /* strings can't be equal */
2434 if (HeKLEN(entry) != len)
2436 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2438 if (HeKFLAGS(entry) != flags_masked)
2444 /* What used to be head of the list.
2445 If this is NULL, then we're the first entry for this slot, which
2446 means we need to increate fill. */
2447 struct shared_he *new_entry;
2450 HE **const head = &HvARRAY(PL_strtab)[hindex];
2451 HE *const next = *head;
2453 /* We don't actually store a HE from the arena and a regular HEK.
2454 Instead we allocate one chunk of memory big enough for both,
2455 and put the HEK straight after the HE. This way we can find the
2456 HEK directly from the HE.
2459 Newx(k, STRUCT_OFFSET(struct shared_he,
2460 shared_he_hek.hek_key[0]) + len + 2, char);
2461 new_entry = (struct shared_he *)k;
2462 entry = &(new_entry->shared_he_he);
2463 hek = &(new_entry->shared_he_hek);
2465 Copy(str, HEK_KEY(hek), len, char);
2466 HEK_KEY(hek)[len] = 0;
2468 HEK_HASH(hek) = hash;
2469 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2471 /* Still "point" to the HEK, so that other code need not know what
2473 HeKEY_hek(entry) = hek;
2474 entry->he_valu.hent_refcount = 0;
2475 HeNEXT(entry) = next;
2478 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2479 if (!next) { /* initial entry? */
2480 xhv->xhv_fill++; /* HvFILL(hv)++ */
2481 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2486 ++entry->he_valu.hent_refcount;
2487 UNLOCK_STRTAB_MUTEX;
2489 if (flags & HVhek_FREEKEY)
2492 return HeKEY_hek(entry);
2496 Perl_hv_placeholders_p(pTHX_ HV *hv)
2499 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2501 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2504 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2507 Perl_die(aTHX_ "panic: hv_placeholders_p");
2510 return &(mg->mg_len);
2515 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2518 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2520 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2522 return mg ? mg->mg_len : 0;
2526 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2529 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2531 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2536 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2537 Perl_die(aTHX_ "panic: hv_placeholders_set");
2539 /* else we don't need to add magic to record 0 placeholders. */
2543 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2548 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2550 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2555 value = &PL_sv_placeholder;
2558 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2561 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2564 case HVrhek_PV_UTF8:
2565 /* Create a string SV that directly points to the bytes in our
2567 value = newSV_type(SVt_PV);
2568 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2569 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2570 /* This stops anything trying to free it */
2571 SvLEN_set(value, 0);
2573 SvREADONLY_on(value);
2574 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2578 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2579 he->refcounted_he_data[0]);
2585 =for apidoc refcounted_he_chain_2hv
2587 Generates and returns a C<HV *> by walking up the tree starting at the passed
2588 in C<struct refcounted_he *>.
2593 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2597 U32 placeholders = 0;
2598 /* We could chase the chain once to get an idea of the number of keys,
2599 and call ksplit. But for now we'll make a potentially inefficient
2600 hash with only 8 entries in its array. */
2601 const U32 max = HvMAX(hv);
2605 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2606 HvARRAY(hv) = (HE**)array;
2611 U32 hash = chain->refcounted_he_hash;
2613 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2615 HE **oentry = &((HvARRAY(hv))[hash & max]);
2616 HE *entry = *oentry;
2619 for (; entry; entry = HeNEXT(entry)) {
2620 if (HeHASH(entry) == hash) {
2621 /* We might have a duplicate key here. If so, entry is older
2622 than the key we've already put in the hash, so if they are
2623 the same, skip adding entry. */
2625 const STRLEN klen = HeKLEN(entry);
2626 const char *const key = HeKEY(entry);
2627 if (klen == chain->refcounted_he_keylen
2628 && (!!HeKUTF8(entry)
2629 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2630 && memEQ(key, REF_HE_KEY(chain), klen))
2633 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2635 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2636 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2637 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2648 = share_hek_flags(REF_HE_KEY(chain),
2649 chain->refcounted_he_keylen,
2650 chain->refcounted_he_hash,
2651 (chain->refcounted_he_data[0]
2652 & (HVhek_UTF8|HVhek_WASUTF8)));
2654 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2656 value = refcounted_he_value(chain);
2657 if (value == &PL_sv_placeholder)
2659 HeVAL(entry) = value;
2661 /* Link it into the chain. */
2662 HeNEXT(entry) = *oentry;
2663 if (!HeNEXT(entry)) {
2664 /* initial entry. */
2672 chain = chain->refcounted_he_next;
2676 clear_placeholders(hv, placeholders);
2677 HvTOTALKEYS(hv) -= placeholders;
2680 /* We could check in the loop to see if we encounter any keys with key
2681 flags, but it's probably not worth it, as this per-hash flag is only
2682 really meant as an optimisation for things like Storable. */
2684 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2690 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2691 const char *key, STRLEN klen, int flags, U32 hash)
2694 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2695 of your key has to exactly match that which is stored. */
2696 SV *value = &PL_sv_placeholder;
2699 /* No point in doing any of this if there's nothing to find. */
2703 if (flags & HVhek_FREEKEY)
2705 key = SvPV_const(keysv, klen);
2707 is_utf8 = (SvUTF8(keysv) != 0);
2709 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2713 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2714 hash = SvSHARED_HASH(keysv);
2716 PERL_HASH(hash, key, klen);
2720 for (; chain; chain = chain->refcounted_he_next) {
2722 if (hash != chain->refcounted_he_hash)
2724 if (klen != chain->refcounted_he_keylen)
2726 if (memNE(REF_HE_KEY(chain),key,klen))
2728 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2731 if (hash != HEK_HASH(chain->refcounted_he_hek))
2733 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2735 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2737 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2741 value = sv_2mortal(refcounted_he_value(chain));
2746 if (flags & HVhek_FREEKEY)
2753 =for apidoc refcounted_he_new
2755 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2756 stored in a compact form, all references remain the property of the caller.
2757 The C<struct refcounted_he> is returned with a reference count of 1.
2762 struct refcounted_he *
2763 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2764 SV *const key, SV *const value) {
2767 const char *key_p = SvPV_const(key, key_len);
2768 STRLEN value_len = 0;
2769 const char *value_p = NULL;
2772 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2775 value_type = HVrhek_PV;
2776 } else if (SvIOK(value)) {
2777 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2778 } else if (value == &PL_sv_placeholder) {
2779 value_type = HVrhek_delete;
2780 } else if (!SvOK(value)) {
2781 value_type = HVrhek_undef;
2783 value_type = HVrhek_PV;
2786 if (value_type == HVrhek_PV) {
2787 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2788 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2789 value_p = SvPV_const(value, value_len);
2791 value_type = HVrhek_PV_UTF8;
2796 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2797 As we're going to be building hash keys from this value in future,
2798 normalise it now. */
2799 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2800 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2803 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2804 ((value_type == HVrhek_PV
2805 || value_type == HVrhek_PV_UTF8) ?
2806 (void *)value_p : (void *)value),
2810 static struct refcounted_he *
2811 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2812 const char *const key_p, const STRLEN key_len,
2813 const char flags, char value_type,
2814 const void *value, const STRLEN value_len) {
2816 struct refcounted_he *he;
2818 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2819 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2821 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2824 he = (struct refcounted_he*)
2825 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2829 he = (struct refcounted_he*)
2830 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2834 he->refcounted_he_next = parent;
2837 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2838 he->refcounted_he_val.refcounted_he_u_len = value_len;
2839 } else if (value_type == HVrhek_IV) {
2840 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2841 } else if (value_type == HVrhek_UV) {
2842 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2845 PERL_HASH(hash, key_p, key_len);
2848 he->refcounted_he_hash = hash;
2849 he->refcounted_he_keylen = key_len;
2850 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2852 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2855 if (flags & HVhek_WASUTF8) {
2856 /* If it was downgraded from UTF-8, then the pointer returned from
2857 bytes_from_utf8 is an allocated pointer that we must free. */
2861 he->refcounted_he_data[0] = flags;
2862 he->refcounted_he_refcnt = 1;
2868 =for apidoc refcounted_he_free
2870 Decrements the reference count of the passed in C<struct refcounted_he *>
2871 by one. If the reference count reaches zero the structure's memory is freed,
2872 and C<refcounted_he_free> iterates onto the parent node.
2878 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2880 PERL_UNUSED_CONTEXT;
2883 struct refcounted_he *copy;
2887 new_count = --he->refcounted_he_refcnt;
2888 HINTS_REFCNT_UNLOCK;
2894 #ifndef USE_ITHREADS
2895 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2898 he = he->refcounted_he_next;
2899 PerlMemShared_free(copy);
2904 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2909 if (chain->refcounted_he_keylen != 1)
2911 if (*REF_HE_KEY(chain) != ':')
2914 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2916 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2919 /* Stop anyone trying to really mess us up by adding their own value for
2921 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2922 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2926 *len = chain->refcounted_he_val.refcounted_he_u_len;
2928 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2929 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
2931 return chain->refcounted_he_data + 1;
2934 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
2935 that interface. Once it works out how to pass in length and UTF-8 ness, this
2936 function will need superseding. */
2937 struct refcounted_he *
2938 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
2940 PERL_ARGS_ASSERT_STORE_COP_LABEL;
2942 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
2943 label, strlen(label));
2947 =for apidoc hv_assert
2949 Check that a hash is in an internally consistent state.
2957 Perl_hv_assert(pTHX_ HV *hv)
2962 int placeholders = 0;
2965 const I32 riter = HvRITER_get(hv);
2966 HE *eiter = HvEITER_get(hv);
2968 PERL_ARGS_ASSERT_HV_ASSERT;
2970 (void)hv_iterinit(hv);
2972 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2973 /* sanity check the values */
2974 if (HeVAL(entry) == &PL_sv_placeholder)
2978 /* sanity check the keys */
2979 if (HeSVKEY(entry)) {
2980 NOOP; /* Don't know what to check on SV keys. */
2981 } else if (HeKUTF8(entry)) {
2983 if (HeKWASUTF8(entry)) {
2984 PerlIO_printf(Perl_debug_log,
2985 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2986 (int) HeKLEN(entry), HeKEY(entry));
2989 } else if (HeKWASUTF8(entry))
2992 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
2993 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2994 const int nhashkeys = HvUSEDKEYS(hv);
2995 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2997 if (nhashkeys != real) {
2998 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3001 if (nhashplaceholders != placeholders) {
3002 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3006 if (withflags && ! HvHASKFLAGS(hv)) {
3007 PerlIO_printf(Perl_debug_log,
3008 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3013 sv_dump(MUTABLE_SV(hv));
3015 HvRITER_set(hv, riter); /* Restore hash iterator state */
3016 HvEITER_set(hv, eiter);
3023 * c-indentation-style: bsd
3025 * indent-tabs-mode: t
3028 * ex: set ts=8 sts=4 sw=4 noet: