3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
4 * 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * "I sit beside the fire and think of all that I have seen." --Bilbo
16 =head1 Hash Manipulation Functions
18 A HV structure represents a Perl hash. It consists mainly of an array
19 of pointers, each of which points to a linked list of HE structures. The
20 array is indexed by the hash function of the key, so each linked list
21 represents all the hash entries with the same hash value. Each HE contains
22 a pointer to the actual value, plus a pointer to a HEK structure which
23 holds the key and hash value.
31 #define PERL_HASH_INTERNAL_ACCESS
34 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
36 static const char S_strtab_error[]
37 = "Cannot modify shared string table in hv_%s";
43 HE* he = (HE*) Perl_get_arena(aTHX_ PERL_ARENA_SIZE, HE_SVSLOT);
44 HE * const heend = &he[PERL_ARENA_SIZE / sizeof(HE) - 1];
46 PL_body_roots[HE_SVSLOT] = he;
48 HeNEXT(he) = (HE*)(he + 1);
56 #define new_HE() (HE*)safemalloc(sizeof(HE))
57 #define del_HE(p) safefree((char*)p)
66 void ** const root = &PL_body_roots[HE_SVSLOT];
76 #define new_HE() new_he()
79 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
80 PL_body_roots[HE_SVSLOT] = p; \
88 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
90 const int flags_masked = flags & HVhek_MASK;
94 Newx(k, HEK_BASESIZE + len + 2, char);
96 Copy(str, HEK_KEY(hek), len, char);
97 HEK_KEY(hek)[len] = 0;
100 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
102 if (flags & HVhek_FREEKEY)
107 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
111 Perl_free_tied_hv_pool(pTHX)
114 HE *he = PL_hv_fetch_ent_mh;
117 Safefree(HeKEY_hek(he));
121 PL_hv_fetch_ent_mh = NULL;
124 #if defined(USE_ITHREADS)
126 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
128 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 PERL_UNUSED_ARG(param);
133 /* We already shared this hash key. */
134 (void)share_hek_hek(shared);
138 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
139 HEK_HASH(source), HEK_FLAGS(source));
140 ptr_table_store(PL_ptr_table, source, shared);
146 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
152 /* look for it in the table first */
153 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
157 /* create anew and remember what it is */
159 ptr_table_store(PL_ptr_table, e, ret);
161 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
162 if (HeKLEN(e) == HEf_SVKEY) {
164 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
165 HeKEY_hek(ret) = (HEK*)k;
166 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
169 /* This is hek_dup inlined, which seems to be important for speed
171 HEK * const source = HeKEY_hek(e);
172 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
175 /* We already shared this hash key. */
176 (void)share_hek_hek(shared);
180 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
181 HEK_HASH(source), HEK_FLAGS(source));
182 ptr_table_store(PL_ptr_table, source, shared);
184 HeKEY_hek(ret) = shared;
187 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
189 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
192 #endif /* USE_ITHREADS */
195 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
198 SV * const sv = sv_newmortal();
199 if (!(flags & HVhek_FREEKEY)) {
200 sv_setpvn(sv, key, klen);
203 /* Need to free saved eventually assign to mortal SV */
204 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
205 sv_usepvn(sv, (char *) key, klen);
207 if (flags & HVhek_UTF8) {
210 Perl_croak(aTHX_ msg, SVfARG(sv));
213 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
219 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
220 the length of the key. The C<hash> parameter is the precomputed hash
221 value; if it is zero then Perl will compute it. The return value will be
222 NULL if the operation failed or if the value did not need to be actually
223 stored within the hash (as in the case of tied hashes). Otherwise it can
224 be dereferenced to get the original C<SV*>. Note that the caller is
225 responsible for suitably incrementing the reference count of C<val> before
226 the call, and decrementing it if the function returned NULL. Effectively
227 a successful hv_store takes ownership of one reference to C<val>. This is
228 usually what you want; a newly created SV has a reference count of one, so
229 if all your code does is create SVs then store them in a hash, hv_store
230 will own the only reference to the new SV, and your code doesn't need to do
231 anything further to tidy up. hv_store is not implemented as a call to
232 hv_store_ent, and does not create a temporary SV for the key, so if your
233 key data is not already in SV form then use hv_store in preference to
236 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
237 information on how to use this function on tied hashes.
239 =for apidoc hv_store_ent
241 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
242 parameter is the precomputed hash value; if it is zero then Perl will
243 compute it. The return value is the new hash entry so created. It will be
244 NULL if the operation failed or if the value did not need to be actually
245 stored within the hash (as in the case of tied hashes). Otherwise the
246 contents of the return value can be accessed using the C<He?> macros
247 described here. Note that the caller is responsible for suitably
248 incrementing the reference count of C<val> before the call, and
249 decrementing it if the function returned NULL. Effectively a successful
250 hv_store_ent takes ownership of one reference to C<val>. This is
251 usually what you want; a newly created SV has a reference count of one, so
252 if all your code does is create SVs then store them in a hash, hv_store
253 will own the only reference to the new SV, and your code doesn't need to do
254 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
255 unlike C<val> it does not take ownership of it, so maintaining the correct
256 reference count on C<key> is entirely the caller's responsibility. hv_store
257 is not implemented as a call to hv_store_ent, and does not create a temporary
258 SV for the key, so if your key data is not already in SV form then use
259 hv_store in preference to hv_store_ent.
261 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
262 information on how to use this function on tied hashes.
264 =for apidoc hv_exists
266 Returns a boolean indicating whether the specified hash key exists. The
267 C<klen> is the length of the key.
271 Returns the SV which corresponds to the specified key in the hash. The
272 C<klen> is the length of the key. If C<lval> is set then the fetch will be
273 part of a store. Check that the return value is non-null before
274 dereferencing it to an C<SV*>.
276 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
277 information on how to use this function on tied hashes.
279 =for apidoc hv_exists_ent
281 Returns a boolean indicating whether the specified hash key exists. C<hash>
282 can be a valid precomputed hash value, or 0 to ask for it to be
288 /* returns an HE * structure with the all fields set */
289 /* note that hent_val will be a mortal sv for MAGICAL hashes */
291 =for apidoc hv_fetch_ent
293 Returns the hash entry which corresponds to the specified key in the hash.
294 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
295 if you want the function to compute it. IF C<lval> is set then the fetch
296 will be part of a store. Make sure the return value is non-null before
297 accessing it. The return value when C<tb> is a tied hash is a pointer to a
298 static location, so be sure to make a copy of the structure if you need to
301 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
302 information on how to use this function on tied hashes.
307 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
309 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
310 const int action, SV *val, const U32 hash)
322 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
326 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
327 int flags, int action, SV *val, register U32 hash)
336 const int return_svp = action & HV_FETCH_JUST_SV;
340 if (SvTYPE(hv) == SVTYPEMASK)
343 assert(SvTYPE(hv) == SVt_PVHV);
345 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
347 if ((mg = mg_find((SV*)hv, PERL_MAGIC_uvar))) {
348 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
349 if (uf->uf_set == NULL) {
350 SV* obj = mg->mg_obj;
353 keysv = sv_2mortal(newSVpvn(key, klen));
354 if (flags & HVhek_UTF8)
358 mg->mg_obj = keysv; /* pass key */
359 uf->uf_index = action; /* pass action */
360 magic_getuvar((SV*)hv, mg);
361 keysv = mg->mg_obj; /* may have changed */
364 /* If the key may have changed, then we need to invalidate
365 any passed-in computed hash value. */
371 if (flags & HVhek_FREEKEY)
373 key = SvPV_const(keysv, klen);
375 is_utf8 = (SvUTF8(keysv) != 0);
377 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
380 if (action & HV_DELETE) {
381 return (void *) hv_delete_common(hv, keysv, key, klen,
382 flags | (is_utf8 ? HVhek_UTF8 : 0),
386 xhv = (XPVHV*)SvANY(hv);
388 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
389 if ( mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv))
391 /* FIXME should be able to skimp on the HE/HEK here when
392 HV_FETCH_JUST_SV is true. */
394 keysv = newSVpvn(key, klen);
399 keysv = newSVsv(keysv);
402 mg_copy((SV*)hv, sv, (char *)keysv, HEf_SVKEY);
404 /* grab a fake HE/HEK pair from the pool or make a new one */
405 entry = PL_hv_fetch_ent_mh;
407 PL_hv_fetch_ent_mh = HeNEXT(entry);
411 Newx(k, HEK_BASESIZE + sizeof(SV*), char);
412 HeKEY_hek(entry) = (HEK*)k;
414 HeNEXT(entry) = NULL;
415 HeSVKEY_set(entry, keysv);
417 sv_upgrade(sv, SVt_PVLV);
419 /* so we can free entry when freeing sv */
420 LvTARG(sv) = (SV*)entry;
422 /* XXX remove at some point? */
423 if (flags & HVhek_FREEKEY)
427 return entry ? (void *) &HeVAL(entry) : NULL;
429 return (void *) entry;
431 #ifdef ENV_IS_CASELESS
432 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
434 for (i = 0; i < klen; ++i)
435 if (isLOWER(key[i])) {
436 /* Would be nice if we had a routine to do the
437 copy and upercase in a single pass through. */
438 const char * const nkey = strupr(savepvn(key,klen));
439 /* Note that this fetch is for nkey (the uppercased
440 key) whereas the store is for key (the original) */
441 void *result = hv_common(hv, NULL, nkey, klen,
442 HVhek_FREEKEY, /* free nkey */
443 0 /* non-LVAL fetch */
444 | HV_DISABLE_UVAR_XKEY
447 0 /* compute hash */);
448 if (!result && (action & HV_FETCH_LVALUE)) {
449 /* This call will free key if necessary.
450 Do it this way to encourage compiler to tail
452 result = hv_common(hv, keysv, key, klen, flags,
454 | HV_DISABLE_UVAR_XKEY
458 if (flags & HVhek_FREEKEY)
466 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
467 if (mg_find((SV*)hv, PERL_MAGIC_tied) || SvGMAGICAL((SV*)hv)) {
468 /* I don't understand why hv_exists_ent has svret and sv,
469 whereas hv_exists only had one. */
470 SV * const svret = sv_newmortal();
473 if (keysv || is_utf8) {
475 keysv = newSVpvn(key, klen);
478 keysv = newSVsv(keysv);
480 mg_copy((SV*)hv, sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
482 mg_copy((SV*)hv, sv, key, klen);
484 if (flags & HVhek_FREEKEY)
486 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
487 /* This cast somewhat evil, but I'm merely using NULL/
488 not NULL to return the boolean exists.
489 And I know hv is not NULL. */
490 return SvTRUE(svret) ? (void *)hv : NULL;
492 #ifdef ENV_IS_CASELESS
493 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
494 /* XXX This code isn't UTF8 clean. */
495 char * const keysave = (char * const)key;
496 /* Will need to free this, so set FREEKEY flag. */
497 key = savepvn(key,klen);
498 key = (const char*)strupr((char*)key);
503 if (flags & HVhek_FREEKEY) {
506 flags |= HVhek_FREEKEY;
510 else if (action & HV_FETCH_ISSTORE) {
513 hv_magic_check (hv, &needs_copy, &needs_store);
515 const bool save_taint = PL_tainted;
516 if (keysv || is_utf8) {
518 keysv = newSVpvn(key, klen);
522 PL_tainted = SvTAINTED(keysv);
523 keysv = sv_2mortal(newSVsv(keysv));
524 mg_copy((SV*)hv, val, (char*)keysv, HEf_SVKEY);
526 mg_copy((SV*)hv, val, key, klen);
529 TAINT_IF(save_taint);
531 if (flags & HVhek_FREEKEY)
535 #ifdef ENV_IS_CASELESS
536 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
537 /* XXX This code isn't UTF8 clean. */
538 const char *keysave = key;
539 /* Will need to free this, so set FREEKEY flag. */
540 key = savepvn(key,klen);
541 key = (const char*)strupr((char*)key);
546 if (flags & HVhek_FREEKEY) {
549 flags |= HVhek_FREEKEY;
557 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
558 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
559 || (SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env))
564 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
566 HvARRAY(hv) = (HE**)array;
568 #ifdef DYNAMIC_ENV_FETCH
569 else if (action & HV_FETCH_ISEXISTS) {
570 /* for an %ENV exists, if we do an insert it's by a recursive
571 store call, so avoid creating HvARRAY(hv) right now. */
575 /* XXX remove at some point? */
576 if (flags & HVhek_FREEKEY)
584 char * const keysave = (char *)key;
585 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
589 flags &= ~HVhek_UTF8;
590 if (key != keysave) {
591 if (flags & HVhek_FREEKEY)
593 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
598 PERL_HASH_INTERNAL(hash, key, klen);
599 /* We don't have a pointer to the hv, so we have to replicate the
600 flag into every HEK, so that hv_iterkeysv can see it. */
601 /* And yes, you do need this even though you are not "storing" because
602 you can flip the flags below if doing an lval lookup. (And that
603 was put in to give the semantics Andreas was expecting.) */
604 flags |= HVhek_REHASH;
606 if (keysv && (SvIsCOW_shared_hash(keysv))) {
607 hash = SvSHARED_HASH(keysv);
609 PERL_HASH(hash, key, klen);
613 masked_flags = (flags & HVhek_MASK);
615 #ifdef DYNAMIC_ENV_FETCH
616 if (!HvARRAY(hv)) entry = NULL;
620 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
622 for (; entry; entry = HeNEXT(entry)) {
623 if (HeHASH(entry) != hash) /* strings can't be equal */
625 if (HeKLEN(entry) != (I32)klen)
627 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
629 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
632 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
633 if (HeKFLAGS(entry) != masked_flags) {
634 /* We match if HVhek_UTF8 bit in our flags and hash key's
635 match. But if entry was set previously with HVhek_WASUTF8
636 and key now doesn't (or vice versa) then we should change
637 the key's flag, as this is assignment. */
638 if (HvSHAREKEYS(hv)) {
639 /* Need to swap the key we have for a key with the flags we
640 need. As keys are shared we can't just write to the
641 flag, so we share the new one, unshare the old one. */
642 HEK * const new_hek = share_hek_flags(key, klen, hash,
644 unshare_hek (HeKEY_hek(entry));
645 HeKEY_hek(entry) = new_hek;
647 else if (hv == PL_strtab) {
648 /* PL_strtab is usually the only hash without HvSHAREKEYS,
649 so putting this test here is cheap */
650 if (flags & HVhek_FREEKEY)
652 Perl_croak(aTHX_ S_strtab_error,
653 action & HV_FETCH_LVALUE ? "fetch" : "store");
656 HeKFLAGS(entry) = masked_flags;
657 if (masked_flags & HVhek_ENABLEHVKFLAGS)
660 if (HeVAL(entry) == &PL_sv_placeholder) {
661 /* yes, can store into placeholder slot */
662 if (action & HV_FETCH_LVALUE) {
664 /* This preserves behaviour with the old hv_fetch
665 implementation which at this point would bail out
666 with a break; (at "if we find a placeholder, we
667 pretend we haven't found anything")
669 That break mean that if a placeholder were found, it
670 caused a call into hv_store, which in turn would
671 check magic, and if there is no magic end up pretty
672 much back at this point (in hv_store's code). */
675 /* LVAL fetch which actaully needs a store. */
677 HvPLACEHOLDERS(hv)--;
680 if (val != &PL_sv_placeholder)
681 HvPLACEHOLDERS(hv)--;
684 } else if (action & HV_FETCH_ISSTORE) {
685 SvREFCNT_dec(HeVAL(entry));
688 } else if (HeVAL(entry) == &PL_sv_placeholder) {
689 /* if we find a placeholder, we pretend we haven't found
693 if (flags & HVhek_FREEKEY)
696 return entry ? (void *) &HeVAL(entry) : NULL;
700 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
701 if (!(action & HV_FETCH_ISSTORE)
702 && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
704 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
706 sv = newSVpvn(env,len);
708 return hv_common(hv, keysv, key, klen, flags,
709 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
715 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
716 hv_notallowed(flags, key, klen,
717 "Attempt to access disallowed key '%"SVf"' in"
718 " a restricted hash");
720 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
721 /* Not doing some form of store, so return failure. */
722 if (flags & HVhek_FREEKEY)
726 if (action & HV_FETCH_LVALUE) {
729 /* At this point the old hv_fetch code would call to hv_store,
730 which in turn might do some tied magic. So we need to make that
731 magic check happen. */
732 /* gonna assign to this, so it better be there */
733 /* If a fetch-as-store fails on the fetch, then the action is to
734 recurse once into "hv_store". If we didn't do this, then that
735 recursive call would call the key conversion routine again.
736 However, as we replace the original key with the converted
737 key, this would result in a double conversion, which would show
738 up as a bug if the conversion routine is not idempotent. */
739 return hv_common(hv, keysv, key, klen, flags,
740 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
742 /* XXX Surely that could leak if the fetch-was-store fails?
743 Just like the hv_fetch. */
747 /* Welcome to hv_store... */
750 /* Not sure if we can get here. I think the only case of oentry being
751 NULL is for %ENV with dynamic env fetch. But that should disappear
752 with magic in the previous code. */
755 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
757 HvARRAY(hv) = (HE**)array;
760 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
763 /* share_hek_flags will do the free for us. This might be considered
766 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
767 else if (hv == PL_strtab) {
768 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
769 this test here is cheap */
770 if (flags & HVhek_FREEKEY)
772 Perl_croak(aTHX_ S_strtab_error,
773 action & HV_FETCH_LVALUE ? "fetch" : "store");
775 else /* gotta do the real thing */
776 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
778 HeNEXT(entry) = *oentry;
781 if (val == &PL_sv_placeholder)
782 HvPLACEHOLDERS(hv)++;
783 if (masked_flags & HVhek_ENABLEHVKFLAGS)
787 const HE *counter = HeNEXT(entry);
789 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
790 if (!counter) { /* initial entry? */
791 xhv->xhv_fill++; /* HvFILL(hv)++ */
792 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
794 } else if(!HvREHASH(hv)) {
797 while ((counter = HeNEXT(counter)))
800 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
801 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
802 bucket splits on a rehashed hash, as we're not going to
803 split it again, and if someone is lucky (evil) enough to
804 get all the keys in one list they could exhaust our memory
805 as we repeatedly double the number of buckets on every
806 entry. Linear search feels a less worse thing to do. */
813 return entry ? (void *) &HeVAL(entry) : NULL;
815 return (void *) entry;
819 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
821 const MAGIC *mg = SvMAGIC(hv);
825 if (isUPPER(mg->mg_type)) {
827 if (mg->mg_type == PERL_MAGIC_tied) {
828 *needs_store = FALSE;
829 return; /* We've set all there is to set. */
832 mg = mg->mg_moremagic;
837 =for apidoc hv_scalar
839 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
845 Perl_hv_scalar(pTHX_ HV *hv)
849 if (SvRMAGICAL(hv)) {
850 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_tied);
852 return magic_scalarpack(hv, mg);
857 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
858 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
866 =for apidoc hv_delete
868 Deletes a key/value pair in the hash. The value SV is removed from the
869 hash and returned to the caller. The C<klen> is the length of the key.
870 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
873 =for apidoc hv_delete_ent
875 Deletes a key/value pair in the hash. The value SV is removed from the
876 hash and returned to the caller. The C<flags> value will normally be zero;
877 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
878 precomputed hash value, or 0 to ask for it to be computed.
884 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
885 int k_flags, I32 d_flags, U32 hash)
890 register HE **oentry;
891 HE *const *first_entry;
892 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
895 if (SvRMAGICAL(hv)) {
898 hv_magic_check (hv, &needs_copy, &needs_store);
902 entry = (HE *) hv_common(hv, keysv, key, klen,
903 k_flags & ~HVhek_FREEKEY,
904 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
906 sv = entry ? HeVAL(entry) : NULL;
912 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
913 /* No longer an element */
914 sv_unmagic(sv, PERL_MAGIC_tiedelem);
917 return NULL; /* element cannot be deleted */
919 #ifdef ENV_IS_CASELESS
920 else if (mg_find((SV*)hv, PERL_MAGIC_env)) {
921 /* XXX This code isn't UTF8 clean. */
922 keysv = sv_2mortal(newSVpvn(key,klen));
923 if (k_flags & HVhek_FREEKEY) {
926 key = strupr(SvPVX(keysv));
935 xhv = (XPVHV*)SvANY(hv);
940 const char * const keysave = key;
941 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
944 k_flags |= HVhek_UTF8;
946 k_flags &= ~HVhek_UTF8;
947 if (key != keysave) {
948 if (k_flags & HVhek_FREEKEY) {
949 /* This shouldn't happen if our caller does what we expect,
950 but strictly the API allows it. */
953 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
955 HvHASKFLAGS_on((SV*)hv);
959 PERL_HASH_INTERNAL(hash, key, klen);
961 if (keysv && (SvIsCOW_shared_hash(keysv))) {
962 hash = SvSHARED_HASH(keysv);
964 PERL_HASH(hash, key, klen);
968 masked_flags = (k_flags & HVhek_MASK);
970 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
972 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
974 if (HeHASH(entry) != hash) /* strings can't be equal */
976 if (HeKLEN(entry) != (I32)klen)
978 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
980 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
983 if (hv == PL_strtab) {
984 if (k_flags & HVhek_FREEKEY)
986 Perl_croak(aTHX_ S_strtab_error, "delete");
989 /* if placeholder is here, it's already been deleted.... */
990 if (HeVAL(entry) == &PL_sv_placeholder) {
991 if (k_flags & HVhek_FREEKEY)
995 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
996 hv_notallowed(k_flags, key, klen,
997 "Attempt to delete readonly key '%"SVf"' from"
998 " a restricted hash");
1000 if (k_flags & HVhek_FREEKEY)
1003 if (d_flags & G_DISCARD)
1006 sv = sv_2mortal(HeVAL(entry));
1007 HeVAL(entry) = &PL_sv_placeholder;
1011 * If a restricted hash, rather than really deleting the entry, put
1012 * a placeholder there. This marks the key as being "approved", so
1013 * we can still access via not-really-existing key without raising
1016 if (SvREADONLY(hv)) {
1017 SvREFCNT_dec(HeVAL(entry));
1018 HeVAL(entry) = &PL_sv_placeholder;
1019 /* We'll be saving this slot, so the number of allocated keys
1020 * doesn't go down, but the number placeholders goes up */
1021 HvPLACEHOLDERS(hv)++;
1023 *oentry = HeNEXT(entry);
1025 xhv->xhv_fill--; /* HvFILL(hv)-- */
1027 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1030 hv_free_ent(hv, entry);
1031 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1032 if (xhv->xhv_keys == 0)
1033 HvHASKFLAGS_off(hv);
1037 if (SvREADONLY(hv)) {
1038 hv_notallowed(k_flags, key, klen,
1039 "Attempt to delete disallowed key '%"SVf"' from"
1040 " a restricted hash");
1043 if (k_flags & HVhek_FREEKEY)
1049 S_hsplit(pTHX_ HV *hv)
1052 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1053 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1054 register I32 newsize = oldsize * 2;
1056 char *a = (char*) HvARRAY(hv);
1058 register HE **oentry;
1059 int longest_chain = 0;
1062 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1063 (void*)hv, (int) oldsize);*/
1065 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1066 /* Can make this clear any placeholders first for non-restricted hashes,
1067 even though Storable rebuilds restricted hashes by putting in all the
1068 placeholders (first) before turning on the readonly flag, because
1069 Storable always pre-splits the hash. */
1070 hv_clear_placeholders(hv);
1074 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1075 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1076 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1082 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1085 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1086 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1091 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1093 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1095 if (oldsize >= 64) {
1096 offer_nice_chunk(HvARRAY(hv),
1097 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1098 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1101 Safefree(HvARRAY(hv));
1105 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1106 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1107 HvARRAY(hv) = (HE**) a;
1110 for (i=0; i<oldsize; i++,aep++) {
1111 int left_length = 0;
1112 int right_length = 0;
1116 if (!*aep) /* non-existent */
1119 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1120 if ((HeHASH(entry) & newsize) != (U32)i) {
1121 *oentry = HeNEXT(entry);
1122 HeNEXT(entry) = *bep;
1124 xhv->xhv_fill++; /* HvFILL(hv)++ */
1130 oentry = &HeNEXT(entry);
1134 if (!*aep) /* everything moved */
1135 xhv->xhv_fill--; /* HvFILL(hv)-- */
1136 /* I think we don't actually need to keep track of the longest length,
1137 merely flag if anything is too long. But for the moment while
1138 developing this code I'll track it. */
1139 if (left_length > longest_chain)
1140 longest_chain = left_length;
1141 if (right_length > longest_chain)
1142 longest_chain = right_length;
1146 /* Pick your policy for "hashing isn't working" here: */
1147 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1152 if (hv == PL_strtab) {
1153 /* Urg. Someone is doing something nasty to the string table.
1158 /* Awooga. Awooga. Pathological data. */
1159 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1160 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1163 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1164 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1166 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1169 was_shared = HvSHAREKEYS(hv);
1172 HvSHAREKEYS_off(hv);
1177 for (i=0; i<newsize; i++,aep++) {
1178 register HE *entry = *aep;
1180 /* We're going to trash this HE's next pointer when we chain it
1181 into the new hash below, so store where we go next. */
1182 HE * const next = HeNEXT(entry);
1187 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1192 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1193 hash, HeKFLAGS(entry));
1194 unshare_hek (HeKEY_hek(entry));
1195 HeKEY_hek(entry) = new_hek;
1197 /* Not shared, so simply write the new hash in. */
1198 HeHASH(entry) = hash;
1200 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1201 HEK_REHASH_on(HeKEY_hek(entry));
1202 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1204 /* Copy oentry to the correct new chain. */
1205 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1207 xhv->xhv_fill++; /* HvFILL(hv)++ */
1208 HeNEXT(entry) = *bep;
1214 Safefree (HvARRAY(hv));
1215 HvARRAY(hv) = (HE **)a;
1219 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1222 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1223 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1224 register I32 newsize;
1229 register HE **oentry;
1231 newsize = (I32) newmax; /* possible truncation here */
1232 if (newsize != newmax || newmax <= oldsize)
1234 while ((newsize & (1 + ~newsize)) != newsize) {
1235 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1237 if (newsize < newmax)
1239 if (newsize < newmax)
1240 return; /* overflow detection */
1242 a = (char *) HvARRAY(hv);
1245 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1246 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1247 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1253 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1256 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1257 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1262 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1264 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1266 if (oldsize >= 64) {
1267 offer_nice_chunk(HvARRAY(hv),
1268 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1269 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1272 Safefree(HvARRAY(hv));
1275 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1278 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1280 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1281 HvARRAY(hv) = (HE **) a;
1282 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1286 for (i=0; i<oldsize; i++,aep++) {
1287 if (!*aep) /* non-existent */
1289 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1290 register I32 j = (HeHASH(entry) & newsize);
1294 *oentry = HeNEXT(entry);
1295 if (!(HeNEXT(entry) = aep[j]))
1296 xhv->xhv_fill++; /* HvFILL(hv)++ */
1301 oentry = &HeNEXT(entry);
1303 if (!*aep) /* everything moved */
1304 xhv->xhv_fill--; /* HvFILL(hv)-- */
1311 Creates a new HV. The reference count is set to 1.
1319 register XPVHV* xhv;
1320 HV * const hv = (HV*)newSV_type(SVt_PVHV);
1321 xhv = (XPVHV*)SvANY(hv);
1323 #ifndef NODEFAULT_SHAREKEYS
1324 HvSHAREKEYS_on(hv); /* key-sharing on by default */
1327 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (start with 8 buckets) */
1328 xhv->xhv_fill = 0; /* HvFILL(hv) = 0 */
1333 Perl_newHVhv(pTHX_ HV *ohv)
1335 HV * const hv = newHV();
1336 STRLEN hv_max, hv_fill;
1338 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1340 hv_max = HvMAX(ohv);
1342 if (!SvMAGICAL((SV *)ohv)) {
1343 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1345 const bool shared = !!HvSHAREKEYS(ohv);
1346 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1348 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1351 /* In each bucket... */
1352 for (i = 0; i <= hv_max; i++) {
1354 HE *oent = oents[i];
1361 /* Copy the linked list of entries. */
1362 for (; oent; oent = HeNEXT(oent)) {
1363 const U32 hash = HeHASH(oent);
1364 const char * const key = HeKEY(oent);
1365 const STRLEN len = HeKLEN(oent);
1366 const int flags = HeKFLAGS(oent);
1367 HE * const ent = new_HE();
1369 HeVAL(ent) = newSVsv(HeVAL(oent));
1371 = shared ? share_hek_flags(key, len, hash, flags)
1372 : save_hek_flags(key, len, hash, flags);
1383 HvFILL(hv) = hv_fill;
1384 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1388 /* Iterate over ohv, copying keys and values one at a time. */
1390 const I32 riter = HvRITER_get(ohv);
1391 HE * const eiter = HvEITER_get(ohv);
1393 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1394 while (hv_max && hv_max + 1 >= hv_fill * 2)
1395 hv_max = hv_max / 2;
1399 while ((entry = hv_iternext_flags(ohv, 0))) {
1400 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1401 newSVsv(HeVAL(entry)), HeHASH(entry),
1404 HvRITER_set(ohv, riter);
1405 HvEITER_set(ohv, eiter);
1411 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1412 magic stays on it. */
1414 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1416 HV * const hv = newHV();
1419 if (ohv && (hv_fill = HvFILL(ohv))) {
1420 STRLEN hv_max = HvMAX(ohv);
1422 const I32 riter = HvRITER_get(ohv);
1423 HE * const eiter = HvEITER_get(ohv);
1425 while (hv_max && hv_max + 1 >= hv_fill * 2)
1426 hv_max = hv_max / 2;
1430 while ((entry = hv_iternext_flags(ohv, 0))) {
1431 SV *const sv = newSVsv(HeVAL(entry));
1432 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1433 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1434 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1435 sv, HeHASH(entry), HeKFLAGS(entry));
1437 HvRITER_set(ohv, riter);
1438 HvEITER_set(ohv, eiter);
1440 hv_magic(hv, NULL, PERL_MAGIC_hints);
1445 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1453 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1454 mro_method_changed_in(hv); /* deletion of method from stash */
1456 if (HeKLEN(entry) == HEf_SVKEY) {
1457 SvREFCNT_dec(HeKEY_sv(entry));
1458 Safefree(HeKEY_hek(entry));
1460 else if (HvSHAREKEYS(hv))
1461 unshare_hek(HeKEY_hek(entry));
1463 Safefree(HeKEY_hek(entry));
1468 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1473 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1474 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1475 if (HeKLEN(entry) == HEf_SVKEY) {
1476 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1478 hv_free_ent(hv, entry);
1482 =for apidoc hv_clear
1484 Clears a hash, making it empty.
1490 Perl_hv_clear(pTHX_ HV *hv)
1493 register XPVHV* xhv;
1497 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1499 xhv = (XPVHV*)SvANY(hv);
1501 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1502 /* restricted hash: convert all keys to placeholders */
1504 for (i = 0; i <= xhv->xhv_max; i++) {
1505 HE *entry = (HvARRAY(hv))[i];
1506 for (; entry; entry = HeNEXT(entry)) {
1507 /* not already placeholder */
1508 if (HeVAL(entry) != &PL_sv_placeholder) {
1509 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1510 SV* const keysv = hv_iterkeysv(entry);
1512 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1515 SvREFCNT_dec(HeVAL(entry));
1516 HeVAL(entry) = &PL_sv_placeholder;
1517 HvPLACEHOLDERS(hv)++;
1525 HvPLACEHOLDERS_set(hv, 0);
1527 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1532 HvHASKFLAGS_off(hv);
1537 mro_isa_changed_in(hv);
1538 HvEITER_set(hv, NULL);
1543 =for apidoc hv_clear_placeholders
1545 Clears any placeholders from a hash. If a restricted hash has any of its keys
1546 marked as readonly and the key is subsequently deleted, the key is not actually
1547 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1548 it so it will be ignored by future operations such as iterating over the hash,
1549 but will still allow the hash to have a value reassigned to the key at some
1550 future point. This function clears any such placeholder keys from the hash.
1551 See Hash::Util::lock_keys() for an example of its use.
1557 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1560 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1563 clear_placeholders(hv, items);
1567 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1577 /* Loop down the linked list heads */
1579 HE **oentry = &(HvARRAY(hv))[i];
1582 while ((entry = *oentry)) {
1583 if (HeVAL(entry) == &PL_sv_placeholder) {
1584 *oentry = HeNEXT(entry);
1585 if (first && !*oentry)
1586 HvFILL(hv)--; /* This linked list is now empty. */
1587 if (entry == HvEITER_get(hv))
1590 hv_free_ent(hv, entry);
1594 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1595 if (HvKEYS(hv) == 0)
1596 HvHASKFLAGS_off(hv);
1597 HvPLACEHOLDERS_set(hv, 0);
1601 oentry = &HeNEXT(entry);
1606 /* You can't get here, hence assertion should always fail. */
1607 assert (items == 0);
1612 S_hfreeentries(pTHX_ HV *hv)
1614 /* This is the array that we're going to restore */
1615 HE **const orig_array = HvARRAY(hv);
1623 /* If the hash is actually a symbol table with a name, look after the
1625 struct xpvhv_aux *iter = HvAUX(hv);
1627 name = iter->xhv_name;
1628 iter->xhv_name = NULL;
1633 /* orig_array remains unchanged throughout the loop. If after freeing all
1634 the entries it turns out that one of the little blighters has triggered
1635 an action that has caused HvARRAY to be re-allocated, then we set
1636 array to the new HvARRAY, and try again. */
1639 /* This is the one we're going to try to empty. First time round
1640 it's the original array. (Hopefully there will only be 1 time
1642 HE ** const array = HvARRAY(hv);
1645 /* Because we have taken xhv_name out, the only allocated pointer
1646 in the aux structure that might exist is the backreference array.
1651 struct mro_meta *meta;
1652 struct xpvhv_aux *iter = HvAUX(hv);
1653 /* If there are weak references to this HV, we need to avoid
1654 freeing them up here. In particular we need to keep the AV
1655 visible as what we're deleting might well have weak references
1656 back to this HV, so the for loop below may well trigger
1657 the removal of backreferences from this array. */
1659 if (iter->xhv_backreferences) {
1660 /* So donate them to regular backref magic to keep them safe.
1661 The sv_magic will increase the reference count of the AV,
1662 so we need to drop it first. */
1663 SvREFCNT_dec(iter->xhv_backreferences);
1664 if (AvFILLp(iter->xhv_backreferences) == -1) {
1665 /* Turns out that the array is empty. Just free it. */
1666 SvREFCNT_dec(iter->xhv_backreferences);
1669 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1670 PERL_MAGIC_backref, NULL, 0);
1672 iter->xhv_backreferences = NULL;
1675 entry = iter->xhv_eiter; /* HvEITER(hv) */
1676 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1678 hv_free_ent(hv, entry);
1680 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1681 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1683 if((meta = iter->xhv_mro_meta)) {
1684 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1685 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1686 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1688 iter->xhv_mro_meta = NULL;
1691 /* There are now no allocated pointers in the aux structure. */
1693 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1694 /* What aux structure? */
1697 /* make everyone else think the array is empty, so that the destructors
1698 * called for freed entries can't recusively mess with us */
1701 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1705 /* Loop down the linked list heads */
1706 HE *entry = array[i];
1709 register HE * const oentry = entry;
1710 entry = HeNEXT(entry);
1711 hv_free_ent(hv, oentry);
1715 /* As there are no allocated pointers in the aux structure, it's now
1716 safe to free the array we just cleaned up, if it's not the one we're
1717 going to put back. */
1718 if (array != orig_array) {
1723 /* Good. No-one added anything this time round. */
1728 /* Someone attempted to iterate or set the hash name while we had
1729 the array set to 0. We'll catch backferences on the next time
1730 round the while loop. */
1731 assert(HvARRAY(hv));
1733 if (HvAUX(hv)->xhv_name) {
1734 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1738 if (--attempts == 0) {
1739 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1743 HvARRAY(hv) = orig_array;
1745 /* If the hash was actually a symbol table, put the name back. */
1747 /* We have restored the original array. If name is non-NULL, then
1748 the original array had an aux structure at the end. So this is
1750 SvFLAGS(hv) |= SVf_OOK;
1751 HvAUX(hv)->xhv_name = name;
1756 =for apidoc hv_undef
1764 Perl_hv_undef(pTHX_ HV *hv)
1767 register XPVHV* xhv;
1772 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1773 xhv = (XPVHV*)SvANY(hv);
1775 if ((name = HvNAME_get(hv)) && !PL_dirty)
1776 mro_isa_changed_in(hv);
1781 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1782 hv_name_set(hv, NULL, 0, 0);
1784 SvFLAGS(hv) &= ~SVf_OOK;
1785 Safefree(HvARRAY(hv));
1786 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1788 HvPLACEHOLDERS_set(hv, 0);
1794 static struct xpvhv_aux*
1795 S_hv_auxinit(HV *hv) {
1796 struct xpvhv_aux *iter;
1800 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1801 + sizeof(struct xpvhv_aux), char);
1803 array = (char *) HvARRAY(hv);
1804 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1805 + sizeof(struct xpvhv_aux), char);
1807 HvARRAY(hv) = (HE**) array;
1808 /* SvOOK_on(hv) attacks the IV flags. */
1809 SvFLAGS(hv) |= SVf_OOK;
1812 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1813 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1815 iter->xhv_backreferences = 0;
1816 iter->xhv_mro_meta = NULL;
1821 =for apidoc hv_iterinit
1823 Prepares a starting point to traverse a hash table. Returns the number of
1824 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1825 currently only meaningful for hashes without tie magic.
1827 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1828 hash buckets that happen to be in use. If you still need that esoteric
1829 value, you can get it through the macro C<HvFILL(tb)>.
1836 Perl_hv_iterinit(pTHX_ HV *hv)
1839 Perl_croak(aTHX_ "Bad hash");
1842 struct xpvhv_aux * const iter = HvAUX(hv);
1843 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1844 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1846 hv_free_ent(hv, entry);
1848 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1849 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1854 /* used to be xhv->xhv_fill before 5.004_65 */
1855 return HvTOTALKEYS(hv);
1859 Perl_hv_riter_p(pTHX_ HV *hv) {
1860 struct xpvhv_aux *iter;
1863 Perl_croak(aTHX_ "Bad hash");
1865 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1866 return &(iter->xhv_riter);
1870 Perl_hv_eiter_p(pTHX_ HV *hv) {
1871 struct xpvhv_aux *iter;
1874 Perl_croak(aTHX_ "Bad hash");
1876 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1877 return &(iter->xhv_eiter);
1881 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1882 struct xpvhv_aux *iter;
1885 Perl_croak(aTHX_ "Bad hash");
1893 iter = hv_auxinit(hv);
1895 iter->xhv_riter = riter;
1899 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1900 struct xpvhv_aux *iter;
1903 Perl_croak(aTHX_ "Bad hash");
1908 /* 0 is the default so don't go malloc()ing a new structure just to
1913 iter = hv_auxinit(hv);
1915 iter->xhv_eiter = eiter;
1919 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1922 struct xpvhv_aux *iter;
1925 PERL_UNUSED_ARG(flags);
1928 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1932 if (iter->xhv_name) {
1933 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1939 iter = hv_auxinit(hv);
1941 PERL_HASH(hash, name, len);
1942 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1946 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1947 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1948 PERL_UNUSED_CONTEXT;
1949 return &(iter->xhv_backreferences);
1953 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
1959 av = HvAUX(hv)->xhv_backreferences;
1962 HvAUX(hv)->xhv_backreferences = 0;
1963 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
1968 hv_iternext is implemented as a macro in hv.h
1970 =for apidoc hv_iternext
1972 Returns entries from a hash iterator. See C<hv_iterinit>.
1974 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1975 iterator currently points to, without losing your place or invalidating your
1976 iterator. Note that in this case the current entry is deleted from the hash
1977 with your iterator holding the last reference to it. Your iterator is flagged
1978 to free the entry on the next call to C<hv_iternext>, so you must not discard
1979 your iterator immediately else the entry will leak - call C<hv_iternext> to
1980 trigger the resource deallocation.
1982 =for apidoc hv_iternext_flags
1984 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1985 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1986 set the placeholders keys (for restricted hashes) will be returned in addition
1987 to normal keys. By default placeholders are automatically skipped over.
1988 Currently a placeholder is implemented with a value that is
1989 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1990 restricted hashes may change, and the implementation currently is
1991 insufficiently abstracted for any change to be tidy.
1997 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2000 register XPVHV* xhv;
2004 struct xpvhv_aux *iter;
2007 Perl_croak(aTHX_ "Bad hash");
2009 xhv = (XPVHV*)SvANY(hv);
2012 /* Too many things (well, pp_each at least) merrily assume that you can
2013 call iv_iternext without calling hv_iterinit, so we'll have to deal
2019 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2020 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2021 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
2022 SV * const key = sv_newmortal();
2024 sv_setsv(key, HeSVKEY_force(entry));
2025 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2031 /* one HE per MAGICAL hash */
2032 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2034 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2036 HeKEY_hek(entry) = hek;
2037 HeKLEN(entry) = HEf_SVKEY;
2039 magic_nextpack((SV*) hv,mg,key);
2041 /* force key to stay around until next time */
2042 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2043 return entry; /* beware, hent_val is not set */
2046 SvREFCNT_dec(HeVAL(entry));
2047 Safefree(HeKEY_hek(entry));
2049 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2053 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2054 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2057 /* The prime_env_iter() on VMS just loaded up new hash values
2058 * so the iteration count needs to be reset back to the beginning
2062 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2067 /* hv_iterint now ensures this. */
2068 assert (HvARRAY(hv));
2070 /* At start of hash, entry is NULL. */
2073 entry = HeNEXT(entry);
2074 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2076 * Skip past any placeholders -- don't want to include them in
2079 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2080 entry = HeNEXT(entry);
2085 /* OK. Come to the end of the current list. Grab the next one. */
2087 iter->xhv_riter++; /* HvRITER(hv)++ */
2088 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2089 /* There is no next one. End of the hash. */
2090 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2093 entry = (HvARRAY(hv))[iter->xhv_riter];
2095 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2096 /* If we have an entry, but it's a placeholder, don't count it.
2098 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2099 entry = HeNEXT(entry);
2101 /* Will loop again if this linked list starts NULL
2102 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2103 or if we run through it and find only placeholders. */
2106 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2108 hv_free_ent(hv, oldentry);
2111 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2112 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2114 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2119 =for apidoc hv_iterkey
2121 Returns the key from the current position of the hash iterator. See
2128 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2130 if (HeKLEN(entry) == HEf_SVKEY) {
2132 char * const p = SvPV(HeKEY_sv(entry), len);
2137 *retlen = HeKLEN(entry);
2138 return HeKEY(entry);
2142 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2144 =for apidoc hv_iterkeysv
2146 Returns the key as an C<SV*> from the current position of the hash
2147 iterator. The return value will always be a mortal copy of the key. Also
2154 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2156 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2160 =for apidoc hv_iterval
2162 Returns the value from the current position of the hash iterator. See
2169 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2171 if (SvRMAGICAL(hv)) {
2172 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2173 SV* const sv = sv_newmortal();
2174 if (HeKLEN(entry) == HEf_SVKEY)
2175 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2177 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2181 return HeVAL(entry);
2185 =for apidoc hv_iternextsv
2187 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2194 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2196 HE * const he = hv_iternext_flags(hv, 0);
2200 *key = hv_iterkey(he, retlen);
2201 return hv_iterval(hv, he);
2208 =for apidoc hv_magic
2210 Adds magic to a hash. See C<sv_magic>.
2215 /* possibly free a shared string if no one has access to it
2216 * len and hash must both be valid for str.
2219 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2221 unshare_hek_or_pvn (NULL, str, len, hash);
2226 Perl_unshare_hek(pTHX_ HEK *hek)
2229 unshare_hek_or_pvn(hek, NULL, 0, 0);
2232 /* possibly free a shared string if no one has access to it
2233 hek if non-NULL takes priority over the other 3, else str, len and hash
2234 are used. If so, len and hash must both be valid for str.
2237 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2240 register XPVHV* xhv;
2242 register HE **oentry;
2244 bool is_utf8 = FALSE;
2246 const char * const save = str;
2247 struct shared_he *he = NULL;
2250 /* Find the shared he which is just before us in memory. */
2251 he = (struct shared_he *)(((char *)hek)
2252 - STRUCT_OFFSET(struct shared_he,
2255 /* Assert that the caller passed us a genuine (or at least consistent)
2257 assert (he->shared_he_he.hent_hek == hek);
2260 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2261 --he->shared_he_he.he_valu.hent_refcount;
2262 UNLOCK_STRTAB_MUTEX;
2265 UNLOCK_STRTAB_MUTEX;
2267 hash = HEK_HASH(hek);
2268 } else if (len < 0) {
2269 STRLEN tmplen = -len;
2271 /* See the note in hv_fetch(). --jhi */
2272 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2275 k_flags = HVhek_UTF8;
2277 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2280 /* what follows was the moral equivalent of:
2281 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2283 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2285 xhv = (XPVHV*)SvANY(PL_strtab);
2286 /* assert(xhv_array != 0) */
2288 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2290 const HE *const he_he = &(he->shared_he_he);
2291 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2296 const int flags_masked = k_flags & HVhek_MASK;
2297 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2298 if (HeHASH(entry) != hash) /* strings can't be equal */
2300 if (HeKLEN(entry) != len)
2302 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2304 if (HeKFLAGS(entry) != flags_masked)
2311 if (--entry->he_valu.hent_refcount == 0) {
2312 *oentry = HeNEXT(entry);
2314 /* There are now no entries in our slot. */
2315 xhv->xhv_fill--; /* HvFILL(hv)-- */
2318 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2322 UNLOCK_STRTAB_MUTEX;
2323 if (!entry && ckWARN_d(WARN_INTERNAL))
2324 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2325 "Attempt to free non-existent shared string '%s'%s"
2327 hek ? HEK_KEY(hek) : str,
2328 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2329 if (k_flags & HVhek_FREEKEY)
2333 /* get a (constant) string ptr from the global string table
2334 * string will get added if it is not already there.
2335 * len and hash must both be valid for str.
2338 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2340 bool is_utf8 = FALSE;
2342 const char * const save = str;
2345 STRLEN tmplen = -len;
2347 /* See the note in hv_fetch(). --jhi */
2348 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2350 /* If we were able to downgrade here, then than means that we were passed
2351 in a key which only had chars 0-255, but was utf8 encoded. */
2354 /* If we found we were able to downgrade the string to bytes, then
2355 we should flag that it needs upgrading on keys or each. Also flag
2356 that we need share_hek_flags to free the string. */
2358 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2361 return share_hek_flags (str, len, hash, flags);
2365 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2369 const int flags_masked = flags & HVhek_MASK;
2370 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2372 /* what follows is the moral equivalent of:
2374 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2375 hv_store(PL_strtab, str, len, NULL, hash);
2377 Can't rehash the shared string table, so not sure if it's worth
2378 counting the number of entries in the linked list
2380 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2381 /* assert(xhv_array != 0) */
2383 entry = (HvARRAY(PL_strtab))[hindex];
2384 for (;entry; entry = HeNEXT(entry)) {
2385 if (HeHASH(entry) != hash) /* strings can't be equal */
2387 if (HeKLEN(entry) != len)
2389 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2391 if (HeKFLAGS(entry) != flags_masked)
2397 /* What used to be head of the list.
2398 If this is NULL, then we're the first entry for this slot, which
2399 means we need to increate fill. */
2400 struct shared_he *new_entry;
2403 HE **const head = &HvARRAY(PL_strtab)[hindex];
2404 HE *const next = *head;
2406 /* We don't actually store a HE from the arena and a regular HEK.
2407 Instead we allocate one chunk of memory big enough for both,
2408 and put the HEK straight after the HE. This way we can find the
2409 HEK directly from the HE.
2412 Newx(k, STRUCT_OFFSET(struct shared_he,
2413 shared_he_hek.hek_key[0]) + len + 2, char);
2414 new_entry = (struct shared_he *)k;
2415 entry = &(new_entry->shared_he_he);
2416 hek = &(new_entry->shared_he_hek);
2418 Copy(str, HEK_KEY(hek), len, char);
2419 HEK_KEY(hek)[len] = 0;
2421 HEK_HASH(hek) = hash;
2422 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2424 /* Still "point" to the HEK, so that other code need not know what
2426 HeKEY_hek(entry) = hek;
2427 entry->he_valu.hent_refcount = 0;
2428 HeNEXT(entry) = next;
2431 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2432 if (!next) { /* initial entry? */
2433 xhv->xhv_fill++; /* HvFILL(hv)++ */
2434 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2439 ++entry->he_valu.hent_refcount;
2440 UNLOCK_STRTAB_MUTEX;
2442 if (flags & HVhek_FREEKEY)
2445 return HeKEY_hek(entry);
2449 Perl_hv_placeholders_p(pTHX_ HV *hv)
2452 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2455 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2458 Perl_die(aTHX_ "panic: hv_placeholders_p");
2461 return &(mg->mg_len);
2466 Perl_hv_placeholders_get(pTHX_ HV *hv)
2469 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2471 return mg ? mg->mg_len : 0;
2475 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2478 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2483 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2484 Perl_die(aTHX_ "panic: hv_placeholders_set");
2486 /* else we don't need to add magic to record 0 placeholders. */
2490 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2494 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2499 value = &PL_sv_placeholder;
2502 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2505 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2508 case HVrhek_PV_UTF8:
2509 /* Create a string SV that directly points to the bytes in our
2511 value = newSV_type(SVt_PV);
2512 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2513 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2514 /* This stops anything trying to free it */
2515 SvLEN_set(value, 0);
2517 SvREADONLY_on(value);
2518 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2522 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2523 he->refcounted_he_data[0]);
2529 =for apidoc refcounted_he_chain_2hv
2531 Generates and returns a C<HV *> by walking up the tree starting at the passed
2532 in C<struct refcounted_he *>.
2537 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2541 U32 placeholders = 0;
2542 /* We could chase the chain once to get an idea of the number of keys,
2543 and call ksplit. But for now we'll make a potentially inefficient
2544 hash with only 8 entries in its array. */
2545 const U32 max = HvMAX(hv);
2549 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2550 HvARRAY(hv) = (HE**)array;
2555 U32 hash = chain->refcounted_he_hash;
2557 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2559 HE **oentry = &((HvARRAY(hv))[hash & max]);
2560 HE *entry = *oentry;
2563 for (; entry; entry = HeNEXT(entry)) {
2564 if (HeHASH(entry) == hash) {
2565 /* We might have a duplicate key here. If so, entry is older
2566 than the key we've already put in the hash, so if they are
2567 the same, skip adding entry. */
2569 const STRLEN klen = HeKLEN(entry);
2570 const char *const key = HeKEY(entry);
2571 if (klen == chain->refcounted_he_keylen
2572 && (!!HeKUTF8(entry)
2573 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2574 && memEQ(key, REF_HE_KEY(chain), klen))
2577 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2579 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2580 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2581 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2592 = share_hek_flags(REF_HE_KEY(chain),
2593 chain->refcounted_he_keylen,
2594 chain->refcounted_he_hash,
2595 (chain->refcounted_he_data[0]
2596 & (HVhek_UTF8|HVhek_WASUTF8)));
2598 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2600 value = refcounted_he_value(chain);
2601 if (value == &PL_sv_placeholder)
2603 HeVAL(entry) = value;
2605 /* Link it into the chain. */
2606 HeNEXT(entry) = *oentry;
2607 if (!HeNEXT(entry)) {
2608 /* initial entry. */
2616 chain = chain->refcounted_he_next;
2620 clear_placeholders(hv, placeholders);
2621 HvTOTALKEYS(hv) -= placeholders;
2624 /* We could check in the loop to see if we encounter any keys with key
2625 flags, but it's probably not worth it, as this per-hash flag is only
2626 really meant as an optimisation for things like Storable. */
2628 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2634 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2635 const char *key, STRLEN klen, int flags, U32 hash)
2638 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2639 of your key has to exactly match that which is stored. */
2640 SV *value = &PL_sv_placeholder;
2644 if (flags & HVhek_FREEKEY)
2646 key = SvPV_const(keysv, klen);
2648 is_utf8 = (SvUTF8(keysv) != 0);
2650 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2654 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2655 hash = SvSHARED_HASH(keysv);
2657 PERL_HASH(hash, key, klen);
2661 for (; chain; chain = chain->refcounted_he_next) {
2663 if (hash != chain->refcounted_he_hash)
2665 if (klen != chain->refcounted_he_keylen)
2667 if (memNE(REF_HE_KEY(chain),key,klen))
2669 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2672 if (hash != HEK_HASH(chain->refcounted_he_hek))
2674 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2676 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2678 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2682 value = sv_2mortal(refcounted_he_value(chain));
2686 if (flags & HVhek_FREEKEY)
2693 =for apidoc refcounted_he_new
2695 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2696 stored in a compact form, all references remain the property of the caller.
2697 The C<struct refcounted_he> is returned with a reference count of 1.
2702 struct refcounted_he *
2703 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2704 SV *const key, SV *const value) {
2706 struct refcounted_he *he;
2708 const char *key_p = SvPV_const(key, key_len);
2709 STRLEN value_len = 0;
2710 const char *value_p = NULL;
2715 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2718 value_type = HVrhek_PV;
2719 } else if (SvIOK(value)) {
2720 value_type = HVrhek_IV;
2721 } else if (value == &PL_sv_placeholder) {
2722 value_type = HVrhek_delete;
2723 } else if (!SvOK(value)) {
2724 value_type = HVrhek_undef;
2726 value_type = HVrhek_PV;
2729 if (value_type == HVrhek_PV) {
2730 value_p = SvPV_const(value, value_len);
2731 key_offset = value_len + 2;
2738 he = (struct refcounted_he*)
2739 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2743 he = (struct refcounted_he*)
2744 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2749 he->refcounted_he_next = parent;
2751 if (value_type == HVrhek_PV) {
2752 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2753 he->refcounted_he_val.refcounted_he_u_len = value_len;
2754 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2755 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2757 value_type = HVrhek_PV_UTF8;
2758 } else if (value_type == HVrhek_IV) {
2760 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2761 value_type = HVrhek_UV;
2763 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2769 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2770 As we're going to be building hash keys from this value in future,
2771 normalise it now. */
2772 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2773 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2775 PERL_HASH(hash, key_p, key_len);
2778 he->refcounted_he_hash = hash;
2779 he->refcounted_he_keylen = key_len;
2780 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2782 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2785 if (flags & HVhek_WASUTF8) {
2786 /* If it was downgraded from UTF-8, then the pointer returned from
2787 bytes_from_utf8 is an allocated pointer that we must free. */
2791 he->refcounted_he_data[0] = flags;
2792 he->refcounted_he_refcnt = 1;
2798 =for apidoc refcounted_he_free
2800 Decrements the reference count of the passed in C<struct refcounted_he *>
2801 by one. If the reference count reaches zero the structure's memory is freed,
2802 and C<refcounted_he_free> iterates onto the parent node.
2808 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2810 PERL_UNUSED_CONTEXT;
2813 struct refcounted_he *copy;
2817 new_count = --he->refcounted_he_refcnt;
2818 HINTS_REFCNT_UNLOCK;
2824 #ifndef USE_ITHREADS
2825 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2828 he = he->refcounted_he_next;
2829 PerlMemShared_free(copy);
2834 =for apidoc hv_assert
2836 Check that a hash is in an internally consistent state.
2844 Perl_hv_assert(pTHX_ HV *hv)
2849 int placeholders = 0;
2852 const I32 riter = HvRITER_get(hv);
2853 HE *eiter = HvEITER_get(hv);
2855 (void)hv_iterinit(hv);
2857 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2858 /* sanity check the values */
2859 if (HeVAL(entry) == &PL_sv_placeholder)
2863 /* sanity check the keys */
2864 if (HeSVKEY(entry)) {
2865 NOOP; /* Don't know what to check on SV keys. */
2866 } else if (HeKUTF8(entry)) {
2868 if (HeKWASUTF8(entry)) {
2869 PerlIO_printf(Perl_debug_log,
2870 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2871 (int) HeKLEN(entry), HeKEY(entry));
2874 } else if (HeKWASUTF8(entry))
2877 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2878 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2879 const int nhashkeys = HvUSEDKEYS(hv);
2880 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2882 if (nhashkeys != real) {
2883 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2886 if (nhashplaceholders != placeholders) {
2887 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2891 if (withflags && ! HvHASKFLAGS(hv)) {
2892 PerlIO_printf(Perl_debug_log,
2893 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2900 HvRITER_set(hv, riter); /* Restore hash iterator state */
2901 HvEITER_set(hv, eiter);
2908 * c-indentation-style: bsd
2910 * indent-tabs-mode: t
2913 * ex: set ts=8 sts=4 sw=4 noet: