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 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
96 Newx(k, HEK_BASESIZE + len + 2, char);
98 Copy(str, HEK_KEY(hek), len, char);
99 HEK_KEY(hek)[len] = 0;
101 HEK_HASH(hek) = hash;
102 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
104 if (flags & HVhek_FREEKEY)
109 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
113 Perl_free_tied_hv_pool(pTHX)
116 HE *he = PL_hv_fetch_ent_mh;
119 Safefree(HeKEY_hek(he));
123 PL_hv_fetch_ent_mh = NULL;
126 #if defined(USE_ITHREADS)
128 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
130 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
132 PERL_ARGS_ASSERT_HEK_DUP;
133 PERL_UNUSED_ARG(param);
136 /* We already shared this hash key. */
137 (void)share_hek_hek(shared);
141 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
142 HEK_HASH(source), HEK_FLAGS(source));
143 ptr_table_store(PL_ptr_table, source, shared);
149 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
153 PERL_ARGS_ASSERT_HE_DUP;
157 /* look for it in the table first */
158 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
162 /* create anew and remember what it is */
164 ptr_table_store(PL_ptr_table, e, ret);
166 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
167 if (HeKLEN(e) == HEf_SVKEY) {
169 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
170 HeKEY_hek(ret) = (HEK*)k;
171 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
174 /* This is hek_dup inlined, which seems to be important for speed
176 HEK * const source = HeKEY_hek(e);
177 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
180 /* We already shared this hash key. */
181 (void)share_hek_hek(shared);
185 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
186 HEK_HASH(source), HEK_FLAGS(source));
187 ptr_table_store(PL_ptr_table, source, shared);
189 HeKEY_hek(ret) = shared;
192 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
194 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
197 #endif /* USE_ITHREADS */
200 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
203 SV * const sv = sv_newmortal();
205 PERL_ARGS_ASSERT_HV_NOTALLOWED;
207 if (!(flags & HVhek_FREEKEY)) {
208 sv_setpvn(sv, key, klen);
211 /* Need to free saved eventually assign to mortal SV */
212 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
213 sv_usepvn(sv, (char *) key, klen);
215 if (flags & HVhek_UTF8) {
218 Perl_croak(aTHX_ msg, SVfARG(sv));
221 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
227 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
228 the length of the key. The C<hash> parameter is the precomputed hash
229 value; if it is zero then Perl will compute it. The return value will be
230 NULL if the operation failed or if the value did not need to be actually
231 stored within the hash (as in the case of tied hashes). Otherwise it can
232 be dereferenced to get the original C<SV*>. Note that the caller is
233 responsible for suitably incrementing the reference count of C<val> before
234 the call, and decrementing it if the function returned NULL. Effectively
235 a successful hv_store takes ownership of one reference to C<val>. This is
236 usually what you want; a newly created SV has a reference count of one, so
237 if all your code does is create SVs then store them in a hash, hv_store
238 will own the only reference to the new SV, and your code doesn't need to do
239 anything further to tidy up. hv_store is not implemented as a call to
240 hv_store_ent, and does not create a temporary SV for the key, so if your
241 key data is not already in SV form then use hv_store in preference to
244 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
245 information on how to use this function on tied hashes.
247 =for apidoc hv_store_ent
249 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
250 parameter is the precomputed hash value; if it is zero then Perl will
251 compute it. The return value is the new hash entry so created. It will be
252 NULL if the operation failed or if the value did not need to be actually
253 stored within the hash (as in the case of tied hashes). Otherwise the
254 contents of the return value can be accessed using the C<He?> macros
255 described here. Note that the caller is responsible for suitably
256 incrementing the reference count of C<val> before the call, and
257 decrementing it if the function returned NULL. Effectively a successful
258 hv_store_ent takes ownership of one reference to C<val>. This is
259 usually what you want; a newly created SV has a reference count of one, so
260 if all your code does is create SVs then store them in a hash, hv_store
261 will own the only reference to the new SV, and your code doesn't need to do
262 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
263 unlike C<val> it does not take ownership of it, so maintaining the correct
264 reference count on C<key> is entirely the caller's responsibility. hv_store
265 is not implemented as a call to hv_store_ent, and does not create a temporary
266 SV for the key, so if your key data is not already in SV form then use
267 hv_store in preference to hv_store_ent.
269 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
270 information on how to use this function on tied hashes.
272 =for apidoc hv_exists
274 Returns a boolean indicating whether the specified hash key exists. The
275 C<klen> is the length of the key.
279 Returns the SV which corresponds to the specified key in the hash. The
280 C<klen> is the length of the key. If C<lval> is set then the fetch will be
281 part of a store. Check that the return value is non-null before
282 dereferencing it to an C<SV*>.
284 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
285 information on how to use this function on tied hashes.
287 =for apidoc hv_exists_ent
289 Returns a boolean indicating whether the specified hash key exists. C<hash>
290 can be a valid precomputed hash value, or 0 to ask for it to be
296 /* returns an HE * structure with the all fields set */
297 /* note that hent_val will be a mortal sv for MAGICAL hashes */
299 =for apidoc hv_fetch_ent
301 Returns the hash entry which corresponds to the specified key in the hash.
302 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
303 if you want the function to compute it. IF C<lval> is set then the fetch
304 will be part of a store. Make sure the return value is non-null before
305 accessing it. The return value when C<tb> is a tied hash is a pointer to a
306 static location, so be sure to make a copy of the structure if you need to
309 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
310 information on how to use this function on tied hashes.
315 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
317 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
318 const int action, SV *val, const U32 hash)
323 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
332 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
336 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
337 int flags, int action, SV *val, register U32 hash)
346 const int return_svp = action & HV_FETCH_JUST_SV;
350 if (SvTYPE(hv) == SVTYPEMASK)
353 assert(SvTYPE(hv) == SVt_PVHV);
355 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
357 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
358 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
359 if (uf->uf_set == NULL) {
360 SV* obj = mg->mg_obj;
363 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
364 ((flags & HVhek_UTF8)
368 mg->mg_obj = keysv; /* pass key */
369 uf->uf_index = action; /* pass action */
370 magic_getuvar((SV*)hv, mg);
371 keysv = mg->mg_obj; /* may have changed */
374 /* If the key may have changed, then we need to invalidate
375 any passed-in computed hash value. */
381 if (flags & HVhek_FREEKEY)
383 key = SvPV_const(keysv, klen);
385 is_utf8 = (SvUTF8(keysv) != 0);
387 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
390 if (action & HV_DELETE) {
391 return (void *) hv_delete_common(hv, keysv, key, klen,
392 flags | (is_utf8 ? HVhek_UTF8 : 0),
396 xhv = (XPVHV*)SvANY(hv);
398 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
399 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
401 /* FIXME should be able to skimp on the HE/HEK here when
402 HV_FETCH_JUST_SV is true. */
404 keysv = newSVpvn_utf8(key, klen, is_utf8);
406 keysv = newSVsv(keysv);
409 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
411 /* grab a fake HE/HEK pair from the pool or make a new one */
412 entry = PL_hv_fetch_ent_mh;
414 PL_hv_fetch_ent_mh = HeNEXT(entry);
418 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
419 HeKEY_hek(entry) = (HEK*)k;
421 HeNEXT(entry) = NULL;
422 HeSVKEY_set(entry, keysv);
424 sv_upgrade(sv, SVt_PVLV);
426 /* so we can free entry when freeing sv */
427 LvTARG(sv) = (SV*)entry;
429 /* XXX remove at some point? */
430 if (flags & HVhek_FREEKEY)
434 return entry ? (void *) &HeVAL(entry) : NULL;
436 return (void *) entry;
438 #ifdef ENV_IS_CASELESS
439 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
441 for (i = 0; i < klen; ++i)
442 if (isLOWER(key[i])) {
443 /* Would be nice if we had a routine to do the
444 copy and upercase in a single pass through. */
445 const char * const nkey = strupr(savepvn(key,klen));
446 /* Note that this fetch is for nkey (the uppercased
447 key) whereas the store is for key (the original) */
448 void *result = hv_common(hv, NULL, nkey, klen,
449 HVhek_FREEKEY, /* free nkey */
450 0 /* non-LVAL fetch */
451 | HV_DISABLE_UVAR_XKEY
454 0 /* compute hash */);
455 if (!result && (action & HV_FETCH_LVALUE)) {
456 /* This call will free key if necessary.
457 Do it this way to encourage compiler to tail
459 result = hv_common(hv, keysv, key, klen, flags,
461 | HV_DISABLE_UVAR_XKEY
465 if (flags & HVhek_FREEKEY)
473 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
474 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
475 /* I don't understand why hv_exists_ent has svret and sv,
476 whereas hv_exists only had one. */
477 SV * const svret = sv_newmortal();
480 if (keysv || is_utf8) {
482 keysv = newSVpvn_utf8(key, klen, TRUE);
484 keysv = newSVsv(keysv);
486 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
488 mg_copy((SV*)hv, sv, key, klen);
490 if (flags & HVhek_FREEKEY)
492 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
493 /* This cast somewhat evil, but I'm merely using NULL/
494 not NULL to return the boolean exists.
495 And I know hv is not NULL. */
496 return SvTRUE(svret) ? (void *)hv : NULL;
498 #ifdef ENV_IS_CASELESS
499 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
500 /* XXX This code isn't UTF8 clean. */
501 char * const keysave = (char * const)key;
502 /* Will need to free this, so set FREEKEY flag. */
503 key = savepvn(key,klen);
504 key = (const char*)strupr((char*)key);
509 if (flags & HVhek_FREEKEY) {
512 flags |= HVhek_FREEKEY;
516 else if (action & HV_FETCH_ISSTORE) {
519 hv_magic_check (hv, &needs_copy, &needs_store);
521 const bool save_taint = PL_tainted;
522 if (keysv || is_utf8) {
524 keysv = newSVpvn_utf8(key, klen, TRUE);
527 PL_tainted = SvTAINTED(keysv);
528 keysv = sv_2mortal(newSVsv(keysv));
529 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
531 mg_copy((SV*)hv, val, key, klen);
534 TAINT_IF(save_taint);
536 if (flags & HVhek_FREEKEY)
540 #ifdef ENV_IS_CASELESS
541 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
542 /* XXX This code isn't UTF8 clean. */
543 const char *keysave = key;
544 /* Will need to free this, so set FREEKEY flag. */
545 key = savepvn(key,klen);
546 key = (const char*)strupr((char*)key);
551 if (flags & HVhek_FREEKEY) {
554 flags |= HVhek_FREEKEY;
562 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
563 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
564 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
569 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
571 HvARRAY(hv) = (HE**)array;
573 #ifdef DYNAMIC_ENV_FETCH
574 else if (action & HV_FETCH_ISEXISTS) {
575 /* for an %ENV exists, if we do an insert it's by a recursive
576 store call, so avoid creating HvARRAY(hv) right now. */
580 /* XXX remove at some point? */
581 if (flags & HVhek_FREEKEY)
589 char * const keysave = (char *)key;
590 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
594 flags &= ~HVhek_UTF8;
595 if (key != keysave) {
596 if (flags & HVhek_FREEKEY)
598 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
603 PERL_HASH_INTERNAL(hash, key, klen);
604 /* We don't have a pointer to the hv, so we have to replicate the
605 flag into every HEK, so that hv_iterkeysv can see it. */
606 /* And yes, you do need this even though you are not "storing" because
607 you can flip the flags below if doing an lval lookup. (And that
608 was put in to give the semantics Andreas was expecting.) */
609 flags |= HVhek_REHASH;
611 if (keysv && (SvIsCOW_shared_hash(keysv))) {
612 hash = SvSHARED_HASH(keysv);
614 PERL_HASH(hash, key, klen);
618 masked_flags = (flags & HVhek_MASK);
620 #ifdef DYNAMIC_ENV_FETCH
621 if (!HvARRAY(hv)) entry = NULL;
625 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
627 for (; entry; entry = HeNEXT(entry)) {
628 if (HeHASH(entry) != hash) /* strings can't be equal */
630 if (HeKLEN(entry) != (I32)klen)
632 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
634 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
637 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
638 if (HeKFLAGS(entry) != masked_flags) {
639 /* We match if HVhek_UTF8 bit in our flags and hash key's
640 match. But if entry was set previously with HVhek_WASUTF8
641 and key now doesn't (or vice versa) then we should change
642 the key's flag, as this is assignment. */
643 if (HvSHAREKEYS(hv)) {
644 /* Need to swap the key we have for a key with the flags we
645 need. As keys are shared we can't just write to the
646 flag, so we share the new one, unshare the old one. */
647 HEK * const new_hek = share_hek_flags(key, klen, hash,
649 unshare_hek (HeKEY_hek(entry));
650 HeKEY_hek(entry) = new_hek;
652 else if (hv == PL_strtab) {
653 /* PL_strtab is usually the only hash without HvSHAREKEYS,
654 so putting this test here is cheap */
655 if (flags & HVhek_FREEKEY)
657 Perl_croak(aTHX_ S_strtab_error,
658 action & HV_FETCH_LVALUE ? "fetch" : "store");
661 HeKFLAGS(entry) = masked_flags;
662 if (masked_flags & HVhek_ENABLEHVKFLAGS)
665 if (HeVAL(entry) == &PL_sv_placeholder) {
666 /* yes, can store into placeholder slot */
667 if (action & HV_FETCH_LVALUE) {
669 /* This preserves behaviour with the old hv_fetch
670 implementation which at this point would bail out
671 with a break; (at "if we find a placeholder, we
672 pretend we haven't found anything")
674 That break mean that if a placeholder were found, it
675 caused a call into hv_store, which in turn would
676 check magic, and if there is no magic end up pretty
677 much back at this point (in hv_store's code). */
680 /* LVAL fetch which actaully needs a store. */
682 HvPLACEHOLDERS(hv)--;
685 if (val != &PL_sv_placeholder)
686 HvPLACEHOLDERS(hv)--;
689 } else if (action & HV_FETCH_ISSTORE) {
690 SvREFCNT_dec(HeVAL(entry));
693 } else if (HeVAL(entry) == &PL_sv_placeholder) {
694 /* if we find a placeholder, we pretend we haven't found
698 if (flags & HVhek_FREEKEY)
701 return entry ? (void *) &HeVAL(entry) : NULL;
705 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
706 if (!(action & HV_FETCH_ISSTORE)
707 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
709 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
711 sv = newSVpvn(env,len);
713 return hv_common(hv, keysv, key, klen, flags,
714 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
720 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
721 hv_notallowed(flags, key, klen,
722 "Attempt to access disallowed key '%"SVf"' in"
723 " a restricted hash");
725 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
726 /* Not doing some form of store, so return failure. */
727 if (flags & HVhek_FREEKEY)
731 if (action & HV_FETCH_LVALUE) {
734 /* At this point the old hv_fetch code would call to hv_store,
735 which in turn might do some tied magic. So we need to make that
736 magic check happen. */
737 /* gonna assign to this, so it better be there */
738 /* If a fetch-as-store fails on the fetch, then the action is to
739 recurse once into "hv_store". If we didn't do this, then that
740 recursive call would call the key conversion routine again.
741 However, as we replace the original key with the converted
742 key, this would result in a double conversion, which would show
743 up as a bug if the conversion routine is not idempotent. */
744 return hv_common(hv, keysv, key, klen, flags,
745 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
747 /* XXX Surely that could leak if the fetch-was-store fails?
748 Just like the hv_fetch. */
752 /* Welcome to hv_store... */
755 /* Not sure if we can get here. I think the only case of oentry being
756 NULL is for %ENV with dynamic env fetch. But that should disappear
757 with magic in the previous code. */
760 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
762 HvARRAY(hv) = (HE**)array;
765 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
768 /* share_hek_flags will do the free for us. This might be considered
771 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
772 else if (hv == PL_strtab) {
773 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
774 this test here is cheap */
775 if (flags & HVhek_FREEKEY)
777 Perl_croak(aTHX_ S_strtab_error,
778 action & HV_FETCH_LVALUE ? "fetch" : "store");
780 else /* gotta do the real thing */
781 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
783 HeNEXT(entry) = *oentry;
786 if (val == &PL_sv_placeholder)
787 HvPLACEHOLDERS(hv)++;
788 if (masked_flags & HVhek_ENABLEHVKFLAGS)
792 const HE *counter = HeNEXT(entry);
794 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
795 if (!counter) { /* initial entry? */
796 xhv->xhv_fill++; /* HvFILL(hv)++ */
797 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
799 } else if(!HvREHASH(hv)) {
802 while ((counter = HeNEXT(counter)))
805 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
806 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
807 bucket splits on a rehashed hash, as we're not going to
808 split it again, and if someone is lucky (evil) enough to
809 get all the keys in one list they could exhaust our memory
810 as we repeatedly double the number of buckets on every
811 entry. Linear search feels a less worse thing to do. */
818 return entry ? (void *) &HeVAL(entry) : NULL;
820 return (void *) entry;
824 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
826 const MAGIC *mg = SvMAGIC(hv);
828 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
833 if (isUPPER(mg->mg_type)) {
835 if (mg->mg_type == PERL_MAGIC_tied) {
836 *needs_store = FALSE;
837 return; /* We've set all there is to set. */
840 mg = mg->mg_moremagic;
845 =for apidoc hv_scalar
847 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
853 Perl_hv_scalar(pTHX_ HV *hv)
857 PERL_ARGS_ASSERT_HV_SCALAR;
859 if (SvRMAGICAL(hv)) {
860 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
862 return magic_scalarpack(hv, mg);
867 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
868 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
876 =for apidoc hv_delete
878 Deletes a key/value pair in the hash. The value SV is removed from the
879 hash and returned to the caller. The C<klen> is the length of the key.
880 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
883 =for apidoc hv_delete_ent
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<flags> value will normally be zero;
887 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
888 precomputed hash value, or 0 to ask for it to be computed.
894 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
895 int k_flags, I32 d_flags, U32 hash)
900 register HE **oentry;
901 HE *const *first_entry;
902 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
905 if (SvRMAGICAL(hv)) {
908 hv_magic_check (hv, &needs_copy, &needs_store);
912 entry = (HE *) hv_common(hv, keysv, key, klen,
913 k_flags & ~HVhek_FREEKEY,
914 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
916 sv = entry ? HeVAL(entry) : NULL;
922 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
923 /* No longer an element */
924 sv_unmagic(sv, PERL_MAGIC_tiedelem);
927 return NULL; /* element cannot be deleted */
929 #ifdef ENV_IS_CASELESS
930 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
931 /* XXX This code isn't UTF8 clean. */
932 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
933 if (k_flags & HVhek_FREEKEY) {
936 key = strupr(SvPVX(keysv));
945 xhv = (XPVHV*)SvANY(hv);
950 const char * const keysave = key;
951 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
954 k_flags |= HVhek_UTF8;
956 k_flags &= ~HVhek_UTF8;
957 if (key != keysave) {
958 if (k_flags & HVhek_FREEKEY) {
959 /* This shouldn't happen if our caller does what we expect,
960 but strictly the API allows it. */
963 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
965 HvHASKFLAGS_on((SV*)hv);
969 PERL_HASH_INTERNAL(hash, key, klen);
971 if (keysv && (SvIsCOW_shared_hash(keysv))) {
972 hash = SvSHARED_HASH(keysv);
974 PERL_HASH(hash, key, klen);
978 masked_flags = (k_flags & HVhek_MASK);
980 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
982 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
984 if (HeHASH(entry) != hash) /* strings can't be equal */
986 if (HeKLEN(entry) != (I32)klen)
988 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
990 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
993 if (hv == PL_strtab) {
994 if (k_flags & HVhek_FREEKEY)
996 Perl_croak(aTHX_ S_strtab_error, "delete");
999 /* if placeholder is here, it's already been deleted.... */
1000 if (HeVAL(entry) == &PL_sv_placeholder) {
1001 if (k_flags & HVhek_FREEKEY)
1005 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1006 hv_notallowed(k_flags, key, klen,
1007 "Attempt to delete readonly key '%"SVf"' from"
1008 " a restricted hash");
1010 if (k_flags & HVhek_FREEKEY)
1013 if (d_flags & G_DISCARD)
1016 sv = sv_2mortal(HeVAL(entry));
1017 HeVAL(entry) = &PL_sv_placeholder;
1021 * If a restricted hash, rather than really deleting the entry, put
1022 * a placeholder there. This marks the key as being "approved", so
1023 * we can still access via not-really-existing key without raising
1026 if (SvREADONLY(hv)) {
1027 SvREFCNT_dec(HeVAL(entry));
1028 HeVAL(entry) = &PL_sv_placeholder;
1029 /* We'll be saving this slot, so the number of allocated keys
1030 * doesn't go down, but the number placeholders goes up */
1031 HvPLACEHOLDERS(hv)++;
1033 *oentry = HeNEXT(entry);
1035 xhv->xhv_fill--; /* HvFILL(hv)-- */
1037 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1040 hv_free_ent(hv, entry);
1041 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1042 if (xhv->xhv_keys == 0)
1043 HvHASKFLAGS_off(hv);
1047 if (SvREADONLY(hv)) {
1048 hv_notallowed(k_flags, key, klen,
1049 "Attempt to delete disallowed key '%"SVf"' from"
1050 " a restricted hash");
1053 if (k_flags & HVhek_FREEKEY)
1059 S_hsplit(pTHX_ HV *hv)
1062 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1063 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1064 register I32 newsize = oldsize * 2;
1066 char *a = (char*) HvARRAY(hv);
1068 register HE **oentry;
1069 int longest_chain = 0;
1072 PERL_ARGS_ASSERT_HSPLIT;
1074 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1075 (void*)hv, (int) oldsize);*/
1077 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1078 /* Can make this clear any placeholders first for non-restricted hashes,
1079 even though Storable rebuilds restricted hashes by putting in all the
1080 placeholders (first) before turning on the readonly flag, because
1081 Storable always pre-splits the hash. */
1082 hv_clear_placeholders(hv);
1086 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1087 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1088 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1094 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1097 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1098 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1103 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1105 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1107 if (oldsize >= 64) {
1108 offer_nice_chunk(HvARRAY(hv),
1109 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1110 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1113 Safefree(HvARRAY(hv));
1117 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1118 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1119 HvARRAY(hv) = (HE**) a;
1122 for (i=0; i<oldsize; i++,aep++) {
1123 int left_length = 0;
1124 int right_length = 0;
1128 if (!*aep) /* non-existent */
1131 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1132 if ((HeHASH(entry) & newsize) != (U32)i) {
1133 *oentry = HeNEXT(entry);
1134 HeNEXT(entry) = *bep;
1136 xhv->xhv_fill++; /* HvFILL(hv)++ */
1142 oentry = &HeNEXT(entry);
1146 if (!*aep) /* everything moved */
1147 xhv->xhv_fill--; /* HvFILL(hv)-- */
1148 /* I think we don't actually need to keep track of the longest length,
1149 merely flag if anything is too long. But for the moment while
1150 developing this code I'll track it. */
1151 if (left_length > longest_chain)
1152 longest_chain = left_length;
1153 if (right_length > longest_chain)
1154 longest_chain = right_length;
1158 /* Pick your policy for "hashing isn't working" here: */
1159 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1164 if (hv == PL_strtab) {
1165 /* Urg. Someone is doing something nasty to the string table.
1170 /* Awooga. Awooga. Pathological data. */
1171 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1172 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1175 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1176 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1178 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1181 was_shared = HvSHAREKEYS(hv);
1184 HvSHAREKEYS_off(hv);
1189 for (i=0; i<newsize; i++,aep++) {
1190 register HE *entry = *aep;
1192 /* We're going to trash this HE's next pointer when we chain it
1193 into the new hash below, so store where we go next. */
1194 HE * const next = HeNEXT(entry);
1199 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1204 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1205 hash, HeKFLAGS(entry));
1206 unshare_hek (HeKEY_hek(entry));
1207 HeKEY_hek(entry) = new_hek;
1209 /* Not shared, so simply write the new hash in. */
1210 HeHASH(entry) = hash;
1212 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1213 HEK_REHASH_on(HeKEY_hek(entry));
1214 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1216 /* Copy oentry to the correct new chain. */
1217 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1219 xhv->xhv_fill++; /* HvFILL(hv)++ */
1220 HeNEXT(entry) = *bep;
1226 Safefree (HvARRAY(hv));
1227 HvARRAY(hv) = (HE **)a;
1231 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1234 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1235 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1236 register I32 newsize;
1241 register HE **oentry;
1243 PERL_ARGS_ASSERT_HV_KSPLIT;
1245 newsize = (I32) newmax; /* possible truncation here */
1246 if (newsize != newmax || newmax <= oldsize)
1248 while ((newsize & (1 + ~newsize)) != newsize) {
1249 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1251 if (newsize < newmax)
1253 if (newsize < newmax)
1254 return; /* overflow detection */
1256 a = (char *) HvARRAY(hv);
1259 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1260 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1261 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1267 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1270 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1271 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1276 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1278 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1280 if (oldsize >= 64) {
1281 offer_nice_chunk(HvARRAY(hv),
1282 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1283 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1286 Safefree(HvARRAY(hv));
1289 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1292 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1294 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1295 HvARRAY(hv) = (HE **) a;
1296 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1300 for (i=0; i<oldsize; i++,aep++) {
1301 if (!*aep) /* non-existent */
1303 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1304 register I32 j = (HeHASH(entry) & newsize);
1308 *oentry = HeNEXT(entry);
1309 if (!(HeNEXT(entry) = aep[j]))
1310 xhv->xhv_fill++; /* HvFILL(hv)++ */
1315 oentry = &HeNEXT(entry);
1317 if (!*aep) /* everything moved */
1318 xhv->xhv_fill--; /* HvFILL(hv)-- */
1323 Perl_newHVhv(pTHX_ HV *ohv)
1325 HV * const hv = newHV();
1326 STRLEN hv_max, hv_fill;
1328 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1330 hv_max = HvMAX(ohv);
1332 if (!SvMAGICAL((SV *)ohv)) {
1333 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1335 const bool shared = !!HvSHAREKEYS(ohv);
1336 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1338 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1341 /* In each bucket... */
1342 for (i = 0; i <= hv_max; i++) {
1344 HE *oent = oents[i];
1351 /* Copy the linked list of entries. */
1352 for (; oent; oent = HeNEXT(oent)) {
1353 const U32 hash = HeHASH(oent);
1354 const char * const key = HeKEY(oent);
1355 const STRLEN len = HeKLEN(oent);
1356 const int flags = HeKFLAGS(oent);
1357 HE * const ent = new_HE();
1359 HeVAL(ent) = newSVsv(HeVAL(oent));
1361 = shared ? share_hek_flags(key, len, hash, flags)
1362 : save_hek_flags(key, len, hash, flags);
1373 HvFILL(hv) = hv_fill;
1374 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1378 /* Iterate over ohv, copying keys and values one at a time. */
1380 const I32 riter = HvRITER_get(ohv);
1381 HE * const eiter = HvEITER_get(ohv);
1383 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1384 while (hv_max && hv_max + 1 >= hv_fill * 2)
1385 hv_max = hv_max / 2;
1389 while ((entry = hv_iternext_flags(ohv, 0))) {
1390 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1391 newSVsv(HeVAL(entry)), HeHASH(entry),
1394 HvRITER_set(ohv, riter);
1395 HvEITER_set(ohv, eiter);
1401 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1402 magic stays on it. */
1404 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1406 HV * const hv = newHV();
1409 if (ohv && (hv_fill = HvFILL(ohv))) {
1410 STRLEN hv_max = HvMAX(ohv);
1412 const I32 riter = HvRITER_get(ohv);
1413 HE * const eiter = HvEITER_get(ohv);
1415 while (hv_max && hv_max + 1 >= hv_fill * 2)
1416 hv_max = hv_max / 2;
1420 while ((entry = hv_iternext_flags(ohv, 0))) {
1421 SV *const sv = newSVsv(HeVAL(entry));
1422 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1423 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1424 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1425 sv, HeHASH(entry), HeKFLAGS(entry));
1427 HvRITER_set(ohv, riter);
1428 HvEITER_set(ohv, eiter);
1430 hv_magic(hv, NULL, PERL_MAGIC_hints);
1435 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1440 PERL_ARGS_ASSERT_HV_FREE_ENT;
1445 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1446 mro_method_changed_in(hv); /* deletion of method from stash */
1448 if (HeKLEN(entry) == HEf_SVKEY) {
1449 SvREFCNT_dec(HeKEY_sv(entry));
1450 Safefree(HeKEY_hek(entry));
1452 else if (HvSHAREKEYS(hv))
1453 unshare_hek(HeKEY_hek(entry));
1455 Safefree(HeKEY_hek(entry));
1460 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1464 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1468 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1469 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1470 if (HeKLEN(entry) == HEf_SVKEY) {
1471 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1473 hv_free_ent(hv, entry);
1477 =for apidoc hv_clear
1479 Clears a hash, making it empty.
1485 Perl_hv_clear(pTHX_ HV *hv)
1488 register XPVHV* xhv;
1492 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1494 xhv = (XPVHV*)SvANY(hv);
1496 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1497 /* restricted hash: convert all keys to placeholders */
1499 for (i = 0; i <= xhv->xhv_max; i++) {
1500 HE *entry = (HvARRAY(hv))[i];
1501 for (; entry; entry = HeNEXT(entry)) {
1502 /* not already placeholder */
1503 if (HeVAL(entry) != &PL_sv_placeholder) {
1504 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1505 SV* const keysv = hv_iterkeysv(entry);
1507 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1510 SvREFCNT_dec(HeVAL(entry));
1511 HeVAL(entry) = &PL_sv_placeholder;
1512 HvPLACEHOLDERS(hv)++;
1520 HvPLACEHOLDERS_set(hv, 0);
1522 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1527 HvHASKFLAGS_off(hv);
1532 mro_isa_changed_in(hv);
1533 HvEITER_set(hv, NULL);
1538 =for apidoc hv_clear_placeholders
1540 Clears any placeholders from a hash. If a restricted hash has any of its keys
1541 marked as readonly and the key is subsequently deleted, the key is not actually
1542 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1543 it so it will be ignored by future operations such as iterating over the hash,
1544 but will still allow the hash to have a value reassigned to the key at some
1545 future point. This function clears any such placeholder keys from the hash.
1546 See Hash::Util::lock_keys() for an example of its use.
1552 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1555 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1557 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1560 clear_placeholders(hv, items);
1564 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1569 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1576 /* Loop down the linked list heads */
1578 HE **oentry = &(HvARRAY(hv))[i];
1581 while ((entry = *oentry)) {
1582 if (HeVAL(entry) == &PL_sv_placeholder) {
1583 *oentry = HeNEXT(entry);
1584 if (first && !*oentry)
1585 HvFILL(hv)--; /* This linked list is now empty. */
1586 if (entry == HvEITER_get(hv))
1589 hv_free_ent(hv, entry);
1593 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1594 if (HvKEYS(hv) == 0)
1595 HvHASKFLAGS_off(hv);
1596 HvPLACEHOLDERS_set(hv, 0);
1600 oentry = &HeNEXT(entry);
1605 /* You can't get here, hence assertion should always fail. */
1606 assert (items == 0);
1611 S_hfreeentries(pTHX_ HV *hv)
1613 /* This is the array that we're going to restore */
1614 HE **const orig_array = HvARRAY(hv);
1618 PERL_ARGS_ASSERT_HFREEENTRIES;
1624 /* If the hash is actually a symbol table with a name, look after the
1626 struct xpvhv_aux *iter = HvAUX(hv);
1628 name = iter->xhv_name;
1629 iter->xhv_name = NULL;
1634 /* orig_array remains unchanged throughout the loop. If after freeing all
1635 the entries it turns out that one of the little blighters has triggered
1636 an action that has caused HvARRAY to be re-allocated, then we set
1637 array to the new HvARRAY, and try again. */
1640 /* This is the one we're going to try to empty. First time round
1641 it's the original array. (Hopefully there will only be 1 time
1643 HE ** const array = HvARRAY(hv);
1646 /* Because we have taken xhv_name out, the only allocated pointer
1647 in the aux structure that might exist is the backreference array.
1652 struct mro_meta *meta;
1653 struct xpvhv_aux *iter = HvAUX(hv);
1654 /* If there are weak references to this HV, we need to avoid
1655 freeing them up here. In particular we need to keep the AV
1656 visible as what we're deleting might well have weak references
1657 back to this HV, so the for loop below may well trigger
1658 the removal of backreferences from this array. */
1660 if (iter->xhv_backreferences) {
1661 /* So donate them to regular backref magic to keep them safe.
1662 The sv_magic will increase the reference count of the AV,
1663 so we need to drop it first. */
1664 SvREFCNT_dec(iter->xhv_backreferences);
1665 if (AvFILLp(iter->xhv_backreferences) == -1) {
1666 /* Turns out that the array is empty. Just free it. */
1667 SvREFCNT_dec(iter->xhv_backreferences);
1670 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1671 PERL_MAGIC_backref, NULL, 0);
1673 iter->xhv_backreferences = NULL;
1676 entry = iter->xhv_eiter; /* HvEITER(hv) */
1677 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1679 hv_free_ent(hv, entry);
1681 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1682 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1684 if((meta = iter->xhv_mro_meta)) {
1685 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1686 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1687 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1689 iter->xhv_mro_meta = NULL;
1692 /* There are now no allocated pointers in the aux structure. */
1694 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1695 /* What aux structure? */
1698 /* make everyone else think the array is empty, so that the destructors
1699 * called for freed entries can't recusively mess with us */
1702 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1706 /* Loop down the linked list heads */
1707 HE *entry = array[i];
1710 register HE * const oentry = entry;
1711 entry = HeNEXT(entry);
1712 hv_free_ent(hv, oentry);
1716 /* As there are no allocated pointers in the aux structure, it's now
1717 safe to free the array we just cleaned up, if it's not the one we're
1718 going to put back. */
1719 if (array != orig_array) {
1724 /* Good. No-one added anything this time round. */
1729 /* Someone attempted to iterate or set the hash name while we had
1730 the array set to 0. We'll catch backferences on the next time
1731 round the while loop. */
1732 assert(HvARRAY(hv));
1734 if (HvAUX(hv)->xhv_name) {
1735 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1739 if (--attempts == 0) {
1740 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1744 HvARRAY(hv) = orig_array;
1746 /* If the hash was actually a symbol table, put the name back. */
1748 /* We have restored the original array. If name is non-NULL, then
1749 the original array had an aux structure at the end. So this is
1751 SvFLAGS(hv) |= SVf_OOK;
1752 HvAUX(hv)->xhv_name = name;
1757 =for apidoc hv_undef
1765 Perl_hv_undef(pTHX_ HV *hv)
1768 register XPVHV* xhv;
1773 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1774 xhv = (XPVHV*)SvANY(hv);
1776 if ((name = HvNAME_get(hv)) && !PL_dirty)
1777 mro_isa_changed_in(hv);
1782 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1783 hv_name_set(hv, NULL, 0, 0);
1785 SvFLAGS(hv) &= ~SVf_OOK;
1786 Safefree(HvARRAY(hv));
1787 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1789 HvPLACEHOLDERS_set(hv, 0);
1795 static struct xpvhv_aux*
1796 S_hv_auxinit(HV *hv) {
1797 struct xpvhv_aux *iter;
1800 PERL_ARGS_ASSERT_HV_AUXINIT;
1803 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1804 + sizeof(struct xpvhv_aux), char);
1806 array = (char *) HvARRAY(hv);
1807 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1808 + sizeof(struct xpvhv_aux), char);
1810 HvARRAY(hv) = (HE**) array;
1811 /* SvOOK_on(hv) attacks the IV flags. */
1812 SvFLAGS(hv) |= SVf_OOK;
1815 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1816 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1818 iter->xhv_backreferences = 0;
1819 iter->xhv_mro_meta = NULL;
1824 =for apidoc hv_iterinit
1826 Prepares a starting point to traverse a hash table. Returns the number of
1827 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1828 currently only meaningful for hashes without tie magic.
1830 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1831 hash buckets that happen to be in use. If you still need that esoteric
1832 value, you can get it through the macro C<HvFILL(tb)>.
1839 Perl_hv_iterinit(pTHX_ HV *hv)
1841 PERL_ARGS_ASSERT_HV_ITERINIT;
1843 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1846 Perl_croak(aTHX_ "Bad hash");
1849 struct xpvhv_aux * const iter = HvAUX(hv);
1850 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1851 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1853 hv_free_ent(hv, entry);
1855 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1856 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1861 /* used to be xhv->xhv_fill before 5.004_65 */
1862 return HvTOTALKEYS(hv);
1866 Perl_hv_riter_p(pTHX_ HV *hv) {
1867 struct xpvhv_aux *iter;
1869 PERL_ARGS_ASSERT_HV_RITER_P;
1872 Perl_croak(aTHX_ "Bad hash");
1874 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1875 return &(iter->xhv_riter);
1879 Perl_hv_eiter_p(pTHX_ HV *hv) {
1880 struct xpvhv_aux *iter;
1882 PERL_ARGS_ASSERT_HV_EITER_P;
1885 Perl_croak(aTHX_ "Bad hash");
1887 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1888 return &(iter->xhv_eiter);
1892 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1893 struct xpvhv_aux *iter;
1895 PERL_ARGS_ASSERT_HV_RITER_SET;
1898 Perl_croak(aTHX_ "Bad hash");
1906 iter = hv_auxinit(hv);
1908 iter->xhv_riter = riter;
1912 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1913 struct xpvhv_aux *iter;
1915 PERL_ARGS_ASSERT_HV_EITER_SET;
1918 Perl_croak(aTHX_ "Bad hash");
1923 /* 0 is the default so don't go malloc()ing a new structure just to
1928 iter = hv_auxinit(hv);
1930 iter->xhv_eiter = eiter;
1934 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1937 struct xpvhv_aux *iter;
1940 PERL_ARGS_ASSERT_HV_NAME_SET;
1941 PERL_UNUSED_ARG(flags);
1944 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1948 if (iter->xhv_name) {
1949 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1955 iter = hv_auxinit(hv);
1957 PERL_HASH(hash, name, len);
1958 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1962 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1963 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1965 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
1966 PERL_UNUSED_CONTEXT;
1968 return &(iter->xhv_backreferences);
1972 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
1975 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
1980 av = HvAUX(hv)->xhv_backreferences;
1983 HvAUX(hv)->xhv_backreferences = 0;
1984 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
1989 hv_iternext is implemented as a macro in hv.h
1991 =for apidoc hv_iternext
1993 Returns entries from a hash iterator. See C<hv_iterinit>.
1995 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1996 iterator currently points to, without losing your place or invalidating your
1997 iterator. Note that in this case the current entry is deleted from the hash
1998 with your iterator holding the last reference to it. Your iterator is flagged
1999 to free the entry on the next call to C<hv_iternext>, so you must not discard
2000 your iterator immediately else the entry will leak - call C<hv_iternext> to
2001 trigger the resource deallocation.
2003 =for apidoc hv_iternext_flags
2005 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2006 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2007 set the placeholders keys (for restricted hashes) will be returned in addition
2008 to normal keys. By default placeholders are automatically skipped over.
2009 Currently a placeholder is implemented with a value that is
2010 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2011 restricted hashes may change, and the implementation currently is
2012 insufficiently abstracted for any change to be tidy.
2018 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2021 register XPVHV* xhv;
2025 struct xpvhv_aux *iter;
2027 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2030 Perl_croak(aTHX_ "Bad hash");
2032 xhv = (XPVHV*)SvANY(hv);
2035 /* Too many things (well, pp_each at least) merrily assume that you can
2036 call iv_iternext without calling hv_iterinit, so we'll have to deal
2042 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2043 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2044 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2045 SV * const key = sv_newmortal();
2047 sv_setsv(key, HeSVKEY_force(entry));
2048 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2054 /* one HE per MAGICAL hash */
2055 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2057 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2059 HeKEY_hek(entry) = hek;
2060 HeKLEN(entry) = HEf_SVKEY;
2062 magic_nextpack((SV*) hv,mg,key);
2064 /* force key to stay around until next time */
2065 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2066 return entry; /* beware, hent_val is not set */
2069 SvREFCNT_dec(HeVAL(entry));
2070 Safefree(HeKEY_hek(entry));
2072 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2076 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2077 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2080 /* The prime_env_iter() on VMS just loaded up new hash values
2081 * so the iteration count needs to be reset back to the beginning
2085 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2090 /* hv_iterint now ensures this. */
2091 assert (HvARRAY(hv));
2093 /* At start of hash, entry is NULL. */
2096 entry = HeNEXT(entry);
2097 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2099 * Skip past any placeholders -- don't want to include them in
2102 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2103 entry = HeNEXT(entry);
2108 /* OK. Come to the end of the current list. Grab the next one. */
2110 iter->xhv_riter++; /* HvRITER(hv)++ */
2111 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2112 /* There is no next one. End of the hash. */
2113 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2116 entry = (HvARRAY(hv))[iter->xhv_riter];
2118 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2119 /* If we have an entry, but it's a placeholder, don't count it.
2121 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2122 entry = HeNEXT(entry);
2124 /* Will loop again if this linked list starts NULL
2125 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2126 or if we run through it and find only placeholders. */
2129 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2131 hv_free_ent(hv, oldentry);
2134 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2135 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2137 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2142 =for apidoc hv_iterkey
2144 Returns the key from the current position of the hash iterator. See
2151 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2153 PERL_ARGS_ASSERT_HV_ITERKEY;
2155 if (HeKLEN(entry) == HEf_SVKEY) {
2157 char * const p = SvPV(HeKEY_sv(entry), len);
2162 *retlen = HeKLEN(entry);
2163 return HeKEY(entry);
2167 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2169 =for apidoc hv_iterkeysv
2171 Returns the key as an C<SV*> from the current position of the hash
2172 iterator. The return value will always be a mortal copy of the key. Also
2179 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2181 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2183 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2187 =for apidoc hv_iterval
2189 Returns the value from the current position of the hash iterator. See
2196 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2198 PERL_ARGS_ASSERT_HV_ITERVAL;
2200 if (SvRMAGICAL(hv)) {
2201 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2202 SV* const sv = sv_newmortal();
2203 if (HeKLEN(entry) == HEf_SVKEY)
2204 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2206 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2210 return HeVAL(entry);
2214 =for apidoc hv_iternextsv
2216 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2223 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2225 HE * const he = hv_iternext_flags(hv, 0);
2227 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2231 *key = hv_iterkey(he, retlen);
2232 return hv_iterval(hv, he);
2239 =for apidoc hv_magic
2241 Adds magic to a hash. See C<sv_magic>.
2246 /* possibly free a shared string if no one has access to it
2247 * len and hash must both be valid for str.
2250 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2252 unshare_hek_or_pvn (NULL, str, len, hash);
2257 Perl_unshare_hek(pTHX_ HEK *hek)
2260 unshare_hek_or_pvn(hek, NULL, 0, 0);
2263 /* possibly free a shared string if no one has access to it
2264 hek if non-NULL takes priority over the other 3, else str, len and hash
2265 are used. If so, len and hash must both be valid for str.
2268 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2271 register XPVHV* xhv;
2273 register HE **oentry;
2275 bool is_utf8 = FALSE;
2277 const char * const save = str;
2278 struct shared_he *he = NULL;
2281 /* Find the shared he which is just before us in memory. */
2282 he = (struct shared_he *)(((char *)hek)
2283 - STRUCT_OFFSET(struct shared_he,
2286 /* Assert that the caller passed us a genuine (or at least consistent)
2288 assert (he->shared_he_he.hent_hek == hek);
2291 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2292 --he->shared_he_he.he_valu.hent_refcount;
2293 UNLOCK_STRTAB_MUTEX;
2296 UNLOCK_STRTAB_MUTEX;
2298 hash = HEK_HASH(hek);
2299 } else if (len < 0) {
2300 STRLEN tmplen = -len;
2302 /* See the note in hv_fetch(). --jhi */
2303 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2306 k_flags = HVhek_UTF8;
2308 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2311 /* what follows was the moral equivalent of:
2312 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2314 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2316 xhv = (XPVHV*)SvANY(PL_strtab);
2317 /* assert(xhv_array != 0) */
2319 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2321 const HE *const he_he = &(he->shared_he_he);
2322 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2327 const int flags_masked = k_flags & HVhek_MASK;
2328 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2329 if (HeHASH(entry) != hash) /* strings can't be equal */
2331 if (HeKLEN(entry) != len)
2333 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2335 if (HeKFLAGS(entry) != flags_masked)
2342 if (--entry->he_valu.hent_refcount == 0) {
2343 *oentry = HeNEXT(entry);
2345 /* There are now no entries in our slot. */
2346 xhv->xhv_fill--; /* HvFILL(hv)-- */
2349 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2353 UNLOCK_STRTAB_MUTEX;
2354 if (!entry && ckWARN_d(WARN_INTERNAL))
2355 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2356 "Attempt to free non-existent shared string '%s'%s"
2358 hek ? HEK_KEY(hek) : str,
2359 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2360 if (k_flags & HVhek_FREEKEY)
2364 /* get a (constant) string ptr from the global string table
2365 * string will get added if it is not already there.
2366 * len and hash must both be valid for str.
2369 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2371 bool is_utf8 = FALSE;
2373 const char * const save = str;
2375 PERL_ARGS_ASSERT_SHARE_HEK;
2378 STRLEN tmplen = -len;
2380 /* See the note in hv_fetch(). --jhi */
2381 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2383 /* If we were able to downgrade here, then than means that we were passed
2384 in a key which only had chars 0-255, but was utf8 encoded. */
2387 /* If we found we were able to downgrade the string to bytes, then
2388 we should flag that it needs upgrading on keys or each. Also flag
2389 that we need share_hek_flags to free the string. */
2391 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2394 return share_hek_flags (str, len, hash, flags);
2398 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2402 const int flags_masked = flags & HVhek_MASK;
2403 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2404 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2406 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2408 /* what follows is the moral equivalent of:
2410 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2411 hv_store(PL_strtab, str, len, NULL, hash);
2413 Can't rehash the shared string table, so not sure if it's worth
2414 counting the number of entries in the linked list
2417 /* assert(xhv_array != 0) */
2419 entry = (HvARRAY(PL_strtab))[hindex];
2420 for (;entry; entry = HeNEXT(entry)) {
2421 if (HeHASH(entry) != hash) /* strings can't be equal */
2423 if (HeKLEN(entry) != len)
2425 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2427 if (HeKFLAGS(entry) != flags_masked)
2433 /* What used to be head of the list.
2434 If this is NULL, then we're the first entry for this slot, which
2435 means we need to increate fill. */
2436 struct shared_he *new_entry;
2439 HE **const head = &HvARRAY(PL_strtab)[hindex];
2440 HE *const next = *head;
2442 /* We don't actually store a HE from the arena and a regular HEK.
2443 Instead we allocate one chunk of memory big enough for both,
2444 and put the HEK straight after the HE. This way we can find the
2445 HEK directly from the HE.
2448 Newx(k, STRUCT_OFFSET(struct shared_he,
2449 shared_he_hek.hek_key[0]) + len + 2, char);
2450 new_entry = (struct shared_he *)k;
2451 entry = &(new_entry->shared_he_he);
2452 hek = &(new_entry->shared_he_hek);
2454 Copy(str, HEK_KEY(hek), len, char);
2455 HEK_KEY(hek)[len] = 0;
2457 HEK_HASH(hek) = hash;
2458 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2460 /* Still "point" to the HEK, so that other code need not know what
2462 HeKEY_hek(entry) = hek;
2463 entry->he_valu.hent_refcount = 0;
2464 HeNEXT(entry) = next;
2467 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2468 if (!next) { /* initial entry? */
2469 xhv->xhv_fill++; /* HvFILL(hv)++ */
2470 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2475 ++entry->he_valu.hent_refcount;
2476 UNLOCK_STRTAB_MUTEX;
2478 if (flags & HVhek_FREEKEY)
2481 return HeKEY_hek(entry);
2485 Perl_hv_placeholders_p(pTHX_ HV *hv)
2488 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2490 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2493 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2496 Perl_die(aTHX_ "panic: hv_placeholders_p");
2499 return &(mg->mg_len);
2504 Perl_hv_placeholders_get(pTHX_ HV *hv)
2507 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2509 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2511 return mg ? mg->mg_len : 0;
2515 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2518 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2520 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2525 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2526 Perl_die(aTHX_ "panic: hv_placeholders_set");
2528 /* else we don't need to add magic to record 0 placeholders. */
2532 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2537 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2539 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2544 value = &PL_sv_placeholder;
2547 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2550 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2553 case HVrhek_PV_UTF8:
2554 /* Create a string SV that directly points to the bytes in our
2556 value = newSV_type(SVt_PV);
2557 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2558 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2559 /* This stops anything trying to free it */
2560 SvLEN_set(value, 0);
2562 SvREADONLY_on(value);
2563 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2567 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2568 he->refcounted_he_data[0]);
2574 =for apidoc refcounted_he_chain_2hv
2576 Generates and returns a C<HV *> by walking up the tree starting at the passed
2577 in C<struct refcounted_he *>.
2582 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2586 U32 placeholders = 0;
2587 /* We could chase the chain once to get an idea of the number of keys,
2588 and call ksplit. But for now we'll make a potentially inefficient
2589 hash with only 8 entries in its array. */
2590 const U32 max = HvMAX(hv);
2594 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2595 HvARRAY(hv) = (HE**)array;
2600 U32 hash = chain->refcounted_he_hash;
2602 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2604 HE **oentry = &((HvARRAY(hv))[hash & max]);
2605 HE *entry = *oentry;
2608 for (; entry; entry = HeNEXT(entry)) {
2609 if (HeHASH(entry) == hash) {
2610 /* We might have a duplicate key here. If so, entry is older
2611 than the key we've already put in the hash, so if they are
2612 the same, skip adding entry. */
2614 const STRLEN klen = HeKLEN(entry);
2615 const char *const key = HeKEY(entry);
2616 if (klen == chain->refcounted_he_keylen
2617 && (!!HeKUTF8(entry)
2618 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2619 && memEQ(key, REF_HE_KEY(chain), klen))
2622 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2624 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2625 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2626 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2637 = share_hek_flags(REF_HE_KEY(chain),
2638 chain->refcounted_he_keylen,
2639 chain->refcounted_he_hash,
2640 (chain->refcounted_he_data[0]
2641 & (HVhek_UTF8|HVhek_WASUTF8)));
2643 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2645 value = refcounted_he_value(chain);
2646 if (value == &PL_sv_placeholder)
2648 HeVAL(entry) = value;
2650 /* Link it into the chain. */
2651 HeNEXT(entry) = *oentry;
2652 if (!HeNEXT(entry)) {
2653 /* initial entry. */
2661 chain = chain->refcounted_he_next;
2665 clear_placeholders(hv, placeholders);
2666 HvTOTALKEYS(hv) -= placeholders;
2669 /* We could check in the loop to see if we encounter any keys with key
2670 flags, but it's probably not worth it, as this per-hash flag is only
2671 really meant as an optimisation for things like Storable. */
2673 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2679 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2680 const char *key, STRLEN klen, int flags, U32 hash)
2683 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2684 of your key has to exactly match that which is stored. */
2685 SV *value = &PL_sv_placeholder;
2689 if (flags & HVhek_FREEKEY)
2691 key = SvPV_const(keysv, klen);
2693 is_utf8 = (SvUTF8(keysv) != 0);
2695 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2699 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2700 hash = SvSHARED_HASH(keysv);
2702 PERL_HASH(hash, key, klen);
2706 for (; chain; chain = chain->refcounted_he_next) {
2708 if (hash != chain->refcounted_he_hash)
2710 if (klen != chain->refcounted_he_keylen)
2712 if (memNE(REF_HE_KEY(chain),key,klen))
2714 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2717 if (hash != HEK_HASH(chain->refcounted_he_hek))
2719 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2721 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2723 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2727 value = sv_2mortal(refcounted_he_value(chain));
2731 if (flags & HVhek_FREEKEY)
2738 =for apidoc refcounted_he_new
2740 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2741 stored in a compact form, all references remain the property of the caller.
2742 The C<struct refcounted_he> is returned with a reference count of 1.
2747 struct refcounted_he *
2748 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2749 SV *const key, SV *const value) {
2751 struct refcounted_he *he;
2753 const char *key_p = SvPV_const(key, key_len);
2754 STRLEN value_len = 0;
2755 const char *value_p = NULL;
2760 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2763 value_type = HVrhek_PV;
2764 } else if (SvIOK(value)) {
2765 value_type = HVrhek_IV;
2766 } else if (value == &PL_sv_placeholder) {
2767 value_type = HVrhek_delete;
2768 } else if (!SvOK(value)) {
2769 value_type = HVrhek_undef;
2771 value_type = HVrhek_PV;
2774 if (value_type == HVrhek_PV) {
2775 value_p = SvPV_const(value, value_len);
2776 key_offset = value_len + 2;
2783 he = (struct refcounted_he*)
2784 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2788 he = (struct refcounted_he*)
2789 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2794 he->refcounted_he_next = parent;
2796 if (value_type == HVrhek_PV) {
2797 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2798 he->refcounted_he_val.refcounted_he_u_len = value_len;
2799 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2800 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2802 value_type = HVrhek_PV_UTF8;
2803 } else if (value_type == HVrhek_IV) {
2805 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2806 value_type = HVrhek_UV;
2808 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2814 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2815 As we're going to be building hash keys from this value in future,
2816 normalise it now. */
2817 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2818 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2820 PERL_HASH(hash, key_p, key_len);
2823 he->refcounted_he_hash = hash;
2824 he->refcounted_he_keylen = key_len;
2825 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2827 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2830 if (flags & HVhek_WASUTF8) {
2831 /* If it was downgraded from UTF-8, then the pointer returned from
2832 bytes_from_utf8 is an allocated pointer that we must free. */
2836 he->refcounted_he_data[0] = flags;
2837 he->refcounted_he_refcnt = 1;
2843 =for apidoc refcounted_he_free
2845 Decrements the reference count of the passed in C<struct refcounted_he *>
2846 by one. If the reference count reaches zero the structure's memory is freed,
2847 and C<refcounted_he_free> iterates onto the parent node.
2853 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2855 PERL_UNUSED_CONTEXT;
2858 struct refcounted_he *copy;
2862 new_count = --he->refcounted_he_refcnt;
2863 HINTS_REFCNT_UNLOCK;
2869 #ifndef USE_ITHREADS
2870 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2873 he = he->refcounted_he_next;
2874 PerlMemShared_free(copy);
2879 =for apidoc hv_assert
2881 Check that a hash is in an internally consistent state.
2889 Perl_hv_assert(pTHX_ HV *hv)
2894 int placeholders = 0;
2897 const I32 riter = HvRITER_get(hv);
2898 HE *eiter = HvEITER_get(hv);
2900 PERL_ARGS_ASSERT_HV_ASSERT;
2902 (void)hv_iterinit(hv);
2904 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2905 /* sanity check the values */
2906 if (HeVAL(entry) == &PL_sv_placeholder)
2910 /* sanity check the keys */
2911 if (HeSVKEY(entry)) {
2912 NOOP; /* Don't know what to check on SV keys. */
2913 } else if (HeKUTF8(entry)) {
2915 if (HeKWASUTF8(entry)) {
2916 PerlIO_printf(Perl_debug_log,
2917 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2918 (int) HeKLEN(entry), HeKEY(entry));
2921 } else if (HeKWASUTF8(entry))
2924 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2925 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2926 const int nhashkeys = HvUSEDKEYS(hv);
2927 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2929 if (nhashkeys != real) {
2930 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2933 if (nhashplaceholders != placeholders) {
2934 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2938 if (withflags && ! HvHASKFLAGS(hv)) {
2939 PerlIO_printf(Perl_debug_log,
2940 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2947 HvRITER_set(hv, riter); /* Restore hash iterator state */
2948 HvEITER_set(hv, eiter);
2955 * c-indentation-style: bsd
2957 * indent-tabs-mode: t
2960 * ex: set ts=8 sts=4 sw=4 noet: