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)-- */
1309 Perl_newHVhv(pTHX_ HV *ohv)
1311 HV * const hv = newHV();
1312 STRLEN hv_max, hv_fill;
1314 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1316 hv_max = HvMAX(ohv);
1318 if (!SvMAGICAL((SV *)ohv)) {
1319 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1321 const bool shared = !!HvSHAREKEYS(ohv);
1322 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1324 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1327 /* In each bucket... */
1328 for (i = 0; i <= hv_max; i++) {
1330 HE *oent = oents[i];
1337 /* Copy the linked list of entries. */
1338 for (; oent; oent = HeNEXT(oent)) {
1339 const U32 hash = HeHASH(oent);
1340 const char * const key = HeKEY(oent);
1341 const STRLEN len = HeKLEN(oent);
1342 const int flags = HeKFLAGS(oent);
1343 HE * const ent = new_HE();
1345 HeVAL(ent) = newSVsv(HeVAL(oent));
1347 = shared ? share_hek_flags(key, len, hash, flags)
1348 : save_hek_flags(key, len, hash, flags);
1359 HvFILL(hv) = hv_fill;
1360 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1364 /* Iterate over ohv, copying keys and values one at a time. */
1366 const I32 riter = HvRITER_get(ohv);
1367 HE * const eiter = HvEITER_get(ohv);
1369 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1370 while (hv_max && hv_max + 1 >= hv_fill * 2)
1371 hv_max = hv_max / 2;
1375 while ((entry = hv_iternext_flags(ohv, 0))) {
1376 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1377 newSVsv(HeVAL(entry)), HeHASH(entry),
1380 HvRITER_set(ohv, riter);
1381 HvEITER_set(ohv, eiter);
1387 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1388 magic stays on it. */
1390 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1392 HV * const hv = newHV();
1395 if (ohv && (hv_fill = HvFILL(ohv))) {
1396 STRLEN hv_max = HvMAX(ohv);
1398 const I32 riter = HvRITER_get(ohv);
1399 HE * const eiter = HvEITER_get(ohv);
1401 while (hv_max && hv_max + 1 >= hv_fill * 2)
1402 hv_max = hv_max / 2;
1406 while ((entry = hv_iternext_flags(ohv, 0))) {
1407 SV *const sv = newSVsv(HeVAL(entry));
1408 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1409 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1410 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1411 sv, HeHASH(entry), HeKFLAGS(entry));
1413 HvRITER_set(ohv, riter);
1414 HvEITER_set(ohv, eiter);
1416 hv_magic(hv, NULL, PERL_MAGIC_hints);
1421 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1429 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1430 mro_method_changed_in(hv); /* deletion of method from stash */
1432 if (HeKLEN(entry) == HEf_SVKEY) {
1433 SvREFCNT_dec(HeKEY_sv(entry));
1434 Safefree(HeKEY_hek(entry));
1436 else if (HvSHAREKEYS(hv))
1437 unshare_hek(HeKEY_hek(entry));
1439 Safefree(HeKEY_hek(entry));
1444 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1449 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1450 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1451 if (HeKLEN(entry) == HEf_SVKEY) {
1452 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1454 hv_free_ent(hv, entry);
1458 =for apidoc hv_clear
1460 Clears a hash, making it empty.
1466 Perl_hv_clear(pTHX_ HV *hv)
1469 register XPVHV* xhv;
1473 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1475 xhv = (XPVHV*)SvANY(hv);
1477 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1478 /* restricted hash: convert all keys to placeholders */
1480 for (i = 0; i <= xhv->xhv_max; i++) {
1481 HE *entry = (HvARRAY(hv))[i];
1482 for (; entry; entry = HeNEXT(entry)) {
1483 /* not already placeholder */
1484 if (HeVAL(entry) != &PL_sv_placeholder) {
1485 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1486 SV* const keysv = hv_iterkeysv(entry);
1488 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1491 SvREFCNT_dec(HeVAL(entry));
1492 HeVAL(entry) = &PL_sv_placeholder;
1493 HvPLACEHOLDERS(hv)++;
1501 HvPLACEHOLDERS_set(hv, 0);
1503 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1508 HvHASKFLAGS_off(hv);
1513 mro_isa_changed_in(hv);
1514 HvEITER_set(hv, NULL);
1519 =for apidoc hv_clear_placeholders
1521 Clears any placeholders from a hash. If a restricted hash has any of its keys
1522 marked as readonly and the key is subsequently deleted, the key is not actually
1523 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1524 it so it will be ignored by future operations such as iterating over the hash,
1525 but will still allow the hash to have a value reassigned to the key at some
1526 future point. This function clears any such placeholder keys from the hash.
1527 See Hash::Util::lock_keys() for an example of its use.
1533 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1536 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1539 clear_placeholders(hv, items);
1543 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1553 /* Loop down the linked list heads */
1555 HE **oentry = &(HvARRAY(hv))[i];
1558 while ((entry = *oentry)) {
1559 if (HeVAL(entry) == &PL_sv_placeholder) {
1560 *oentry = HeNEXT(entry);
1561 if (first && !*oentry)
1562 HvFILL(hv)--; /* This linked list is now empty. */
1563 if (entry == HvEITER_get(hv))
1566 hv_free_ent(hv, entry);
1570 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1571 if (HvKEYS(hv) == 0)
1572 HvHASKFLAGS_off(hv);
1573 HvPLACEHOLDERS_set(hv, 0);
1577 oentry = &HeNEXT(entry);
1582 /* You can't get here, hence assertion should always fail. */
1583 assert (items == 0);
1588 S_hfreeentries(pTHX_ HV *hv)
1590 /* This is the array that we're going to restore */
1591 HE **const orig_array = HvARRAY(hv);
1599 /* If the hash is actually a symbol table with a name, look after the
1601 struct xpvhv_aux *iter = HvAUX(hv);
1603 name = iter->xhv_name;
1604 iter->xhv_name = NULL;
1609 /* orig_array remains unchanged throughout the loop. If after freeing all
1610 the entries it turns out that one of the little blighters has triggered
1611 an action that has caused HvARRAY to be re-allocated, then we set
1612 array to the new HvARRAY, and try again. */
1615 /* This is the one we're going to try to empty. First time round
1616 it's the original array. (Hopefully there will only be 1 time
1618 HE ** const array = HvARRAY(hv);
1621 /* Because we have taken xhv_name out, the only allocated pointer
1622 in the aux structure that might exist is the backreference array.
1627 struct mro_meta *meta;
1628 struct xpvhv_aux *iter = HvAUX(hv);
1629 /* If there are weak references to this HV, we need to avoid
1630 freeing them up here. In particular we need to keep the AV
1631 visible as what we're deleting might well have weak references
1632 back to this HV, so the for loop below may well trigger
1633 the removal of backreferences from this array. */
1635 if (iter->xhv_backreferences) {
1636 /* So donate them to regular backref magic to keep them safe.
1637 The sv_magic will increase the reference count of the AV,
1638 so we need to drop it first. */
1639 SvREFCNT_dec(iter->xhv_backreferences);
1640 if (AvFILLp(iter->xhv_backreferences) == -1) {
1641 /* Turns out that the array is empty. Just free it. */
1642 SvREFCNT_dec(iter->xhv_backreferences);
1645 sv_magic((SV*)hv, (SV*)iter->xhv_backreferences,
1646 PERL_MAGIC_backref, NULL, 0);
1648 iter->xhv_backreferences = NULL;
1651 entry = iter->xhv_eiter; /* HvEITER(hv) */
1652 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1654 hv_free_ent(hv, entry);
1656 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1657 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1659 if((meta = iter->xhv_mro_meta)) {
1660 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1661 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1662 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1664 iter->xhv_mro_meta = NULL;
1667 /* There are now no allocated pointers in the aux structure. */
1669 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1670 /* What aux structure? */
1673 /* make everyone else think the array is empty, so that the destructors
1674 * called for freed entries can't recusively mess with us */
1677 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1681 /* Loop down the linked list heads */
1682 HE *entry = array[i];
1685 register HE * const oentry = entry;
1686 entry = HeNEXT(entry);
1687 hv_free_ent(hv, oentry);
1691 /* As there are no allocated pointers in the aux structure, it's now
1692 safe to free the array we just cleaned up, if it's not the one we're
1693 going to put back. */
1694 if (array != orig_array) {
1699 /* Good. No-one added anything this time round. */
1704 /* Someone attempted to iterate or set the hash name while we had
1705 the array set to 0. We'll catch backferences on the next time
1706 round the while loop. */
1707 assert(HvARRAY(hv));
1709 if (HvAUX(hv)->xhv_name) {
1710 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1714 if (--attempts == 0) {
1715 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1719 HvARRAY(hv) = orig_array;
1721 /* If the hash was actually a symbol table, put the name back. */
1723 /* We have restored the original array. If name is non-NULL, then
1724 the original array had an aux structure at the end. So this is
1726 SvFLAGS(hv) |= SVf_OOK;
1727 HvAUX(hv)->xhv_name = name;
1732 =for apidoc hv_undef
1740 Perl_hv_undef(pTHX_ HV *hv)
1743 register XPVHV* xhv;
1748 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1749 xhv = (XPVHV*)SvANY(hv);
1751 if ((name = HvNAME_get(hv)) && !PL_dirty)
1752 mro_isa_changed_in(hv);
1757 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1758 hv_name_set(hv, NULL, 0, 0);
1760 SvFLAGS(hv) &= ~SVf_OOK;
1761 Safefree(HvARRAY(hv));
1762 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1764 HvPLACEHOLDERS_set(hv, 0);
1770 static struct xpvhv_aux*
1771 S_hv_auxinit(HV *hv) {
1772 struct xpvhv_aux *iter;
1776 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1777 + sizeof(struct xpvhv_aux), char);
1779 array = (char *) HvARRAY(hv);
1780 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1781 + sizeof(struct xpvhv_aux), char);
1783 HvARRAY(hv) = (HE**) array;
1784 /* SvOOK_on(hv) attacks the IV flags. */
1785 SvFLAGS(hv) |= SVf_OOK;
1788 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1789 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1791 iter->xhv_backreferences = 0;
1792 iter->xhv_mro_meta = NULL;
1797 =for apidoc hv_iterinit
1799 Prepares a starting point to traverse a hash table. Returns the number of
1800 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1801 currently only meaningful for hashes without tie magic.
1803 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1804 hash buckets that happen to be in use. If you still need that esoteric
1805 value, you can get it through the macro C<HvFILL(tb)>.
1812 Perl_hv_iterinit(pTHX_ HV *hv)
1815 Perl_croak(aTHX_ "Bad hash");
1818 struct xpvhv_aux * const iter = HvAUX(hv);
1819 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1820 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1822 hv_free_ent(hv, entry);
1824 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1825 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1830 /* used to be xhv->xhv_fill before 5.004_65 */
1831 return HvTOTALKEYS(hv);
1835 Perl_hv_riter_p(pTHX_ HV *hv) {
1836 struct xpvhv_aux *iter;
1839 Perl_croak(aTHX_ "Bad hash");
1841 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1842 return &(iter->xhv_riter);
1846 Perl_hv_eiter_p(pTHX_ HV *hv) {
1847 struct xpvhv_aux *iter;
1850 Perl_croak(aTHX_ "Bad hash");
1852 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1853 return &(iter->xhv_eiter);
1857 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1858 struct xpvhv_aux *iter;
1861 Perl_croak(aTHX_ "Bad hash");
1869 iter = hv_auxinit(hv);
1871 iter->xhv_riter = riter;
1875 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1876 struct xpvhv_aux *iter;
1879 Perl_croak(aTHX_ "Bad hash");
1884 /* 0 is the default so don't go malloc()ing a new structure just to
1889 iter = hv_auxinit(hv);
1891 iter->xhv_eiter = eiter;
1895 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1898 struct xpvhv_aux *iter;
1901 PERL_UNUSED_ARG(flags);
1904 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1908 if (iter->xhv_name) {
1909 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1915 iter = hv_auxinit(hv);
1917 PERL_HASH(hash, name, len);
1918 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1922 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1923 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1924 PERL_UNUSED_CONTEXT;
1925 return &(iter->xhv_backreferences);
1929 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
1935 av = HvAUX(hv)->xhv_backreferences;
1938 HvAUX(hv)->xhv_backreferences = 0;
1939 Perl_sv_kill_backrefs(aTHX_ (SV*) hv, av);
1944 hv_iternext is implemented as a macro in hv.h
1946 =for apidoc hv_iternext
1948 Returns entries from a hash iterator. See C<hv_iterinit>.
1950 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
1951 iterator currently points to, without losing your place or invalidating your
1952 iterator. Note that in this case the current entry is deleted from the hash
1953 with your iterator holding the last reference to it. Your iterator is flagged
1954 to free the entry on the next call to C<hv_iternext>, so you must not discard
1955 your iterator immediately else the entry will leak - call C<hv_iternext> to
1956 trigger the resource deallocation.
1958 =for apidoc hv_iternext_flags
1960 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
1961 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
1962 set the placeholders keys (for restricted hashes) will be returned in addition
1963 to normal keys. By default placeholders are automatically skipped over.
1964 Currently a placeholder is implemented with a value that is
1965 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
1966 restricted hashes may change, and the implementation currently is
1967 insufficiently abstracted for any change to be tidy.
1973 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
1976 register XPVHV* xhv;
1980 struct xpvhv_aux *iter;
1983 Perl_croak(aTHX_ "Bad hash");
1985 xhv = (XPVHV*)SvANY(hv);
1988 /* Too many things (well, pp_each at least) merrily assume that you can
1989 call iv_iternext without calling hv_iterinit, so we'll have to deal
1995 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
1996 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
1997 if ( ( mg = mg_find((SV*)hv, PERL_MAGIC_tied) ) ) {
1998 SV * const key = sv_newmortal();
2000 sv_setsv(key, HeSVKEY_force(entry));
2001 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2007 /* one HE per MAGICAL hash */
2008 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2010 Newxz(k, HEK_BASESIZE + sizeof(SV*), char);
2012 HeKEY_hek(entry) = hek;
2013 HeKLEN(entry) = HEf_SVKEY;
2015 magic_nextpack((SV*) hv,mg,key);
2017 /* force key to stay around until next time */
2018 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2019 return entry; /* beware, hent_val is not set */
2022 SvREFCNT_dec(HeVAL(entry));
2023 Safefree(HeKEY_hek(entry));
2025 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2029 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2030 if (!entry && SvRMAGICAL((SV*)hv) && mg_find((SV*)hv, PERL_MAGIC_env)) {
2033 /* The prime_env_iter() on VMS just loaded up new hash values
2034 * so the iteration count needs to be reset back to the beginning
2038 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2043 /* hv_iterint now ensures this. */
2044 assert (HvARRAY(hv));
2046 /* At start of hash, entry is NULL. */
2049 entry = HeNEXT(entry);
2050 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2052 * Skip past any placeholders -- don't want to include them in
2055 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2056 entry = HeNEXT(entry);
2061 /* OK. Come to the end of the current list. Grab the next one. */
2063 iter->xhv_riter++; /* HvRITER(hv)++ */
2064 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2065 /* There is no next one. End of the hash. */
2066 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2069 entry = (HvARRAY(hv))[iter->xhv_riter];
2071 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2072 /* If we have an entry, but it's a placeholder, don't count it.
2074 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2075 entry = HeNEXT(entry);
2077 /* Will loop again if this linked list starts NULL
2078 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2079 or if we run through it and find only placeholders. */
2082 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2084 hv_free_ent(hv, oldentry);
2087 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2088 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2090 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2095 =for apidoc hv_iterkey
2097 Returns the key from the current position of the hash iterator. See
2104 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2106 if (HeKLEN(entry) == HEf_SVKEY) {
2108 char * const p = SvPV(HeKEY_sv(entry), len);
2113 *retlen = HeKLEN(entry);
2114 return HeKEY(entry);
2118 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2120 =for apidoc hv_iterkeysv
2122 Returns the key as an C<SV*> from the current position of the hash
2123 iterator. The return value will always be a mortal copy of the key. Also
2130 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2132 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2136 =for apidoc hv_iterval
2138 Returns the value from the current position of the hash iterator. See
2145 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2147 if (SvRMAGICAL(hv)) {
2148 if (mg_find((SV*)hv, PERL_MAGIC_tied)) {
2149 SV* const sv = sv_newmortal();
2150 if (HeKLEN(entry) == HEf_SVKEY)
2151 mg_copy((SV*)hv, sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2153 mg_copy((SV*)hv, sv, HeKEY(entry), HeKLEN(entry));
2157 return HeVAL(entry);
2161 =for apidoc hv_iternextsv
2163 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2170 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2172 HE * const he = hv_iternext_flags(hv, 0);
2176 *key = hv_iterkey(he, retlen);
2177 return hv_iterval(hv, he);
2184 =for apidoc hv_magic
2186 Adds magic to a hash. See C<sv_magic>.
2191 /* possibly free a shared string if no one has access to it
2192 * len and hash must both be valid for str.
2195 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2197 unshare_hek_or_pvn (NULL, str, len, hash);
2202 Perl_unshare_hek(pTHX_ HEK *hek)
2205 unshare_hek_or_pvn(hek, NULL, 0, 0);
2208 /* possibly free a shared string if no one has access to it
2209 hek if non-NULL takes priority over the other 3, else str, len and hash
2210 are used. If so, len and hash must both be valid for str.
2213 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2216 register XPVHV* xhv;
2218 register HE **oentry;
2220 bool is_utf8 = FALSE;
2222 const char * const save = str;
2223 struct shared_he *he = NULL;
2226 /* Find the shared he which is just before us in memory. */
2227 he = (struct shared_he *)(((char *)hek)
2228 - STRUCT_OFFSET(struct shared_he,
2231 /* Assert that the caller passed us a genuine (or at least consistent)
2233 assert (he->shared_he_he.hent_hek == hek);
2236 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2237 --he->shared_he_he.he_valu.hent_refcount;
2238 UNLOCK_STRTAB_MUTEX;
2241 UNLOCK_STRTAB_MUTEX;
2243 hash = HEK_HASH(hek);
2244 } else if (len < 0) {
2245 STRLEN tmplen = -len;
2247 /* See the note in hv_fetch(). --jhi */
2248 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2251 k_flags = HVhek_UTF8;
2253 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2256 /* what follows was the moral equivalent of:
2257 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2259 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2261 xhv = (XPVHV*)SvANY(PL_strtab);
2262 /* assert(xhv_array != 0) */
2264 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2266 const HE *const he_he = &(he->shared_he_he);
2267 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2272 const int flags_masked = k_flags & HVhek_MASK;
2273 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2274 if (HeHASH(entry) != hash) /* strings can't be equal */
2276 if (HeKLEN(entry) != len)
2278 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2280 if (HeKFLAGS(entry) != flags_masked)
2287 if (--entry->he_valu.hent_refcount == 0) {
2288 *oentry = HeNEXT(entry);
2290 /* There are now no entries in our slot. */
2291 xhv->xhv_fill--; /* HvFILL(hv)-- */
2294 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2298 UNLOCK_STRTAB_MUTEX;
2299 if (!entry && ckWARN_d(WARN_INTERNAL))
2300 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2301 "Attempt to free non-existent shared string '%s'%s"
2303 hek ? HEK_KEY(hek) : str,
2304 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2305 if (k_flags & HVhek_FREEKEY)
2309 /* get a (constant) string ptr from the global string table
2310 * string will get added if it is not already there.
2311 * len and hash must both be valid for str.
2314 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2316 bool is_utf8 = FALSE;
2318 const char * const save = str;
2321 STRLEN tmplen = -len;
2323 /* See the note in hv_fetch(). --jhi */
2324 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2326 /* If we were able to downgrade here, then than means that we were passed
2327 in a key which only had chars 0-255, but was utf8 encoded. */
2330 /* If we found we were able to downgrade the string to bytes, then
2331 we should flag that it needs upgrading on keys or each. Also flag
2332 that we need share_hek_flags to free the string. */
2334 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2337 return share_hek_flags (str, len, hash, flags);
2341 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2345 const int flags_masked = flags & HVhek_MASK;
2346 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2348 /* what follows is the moral equivalent of:
2350 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2351 hv_store(PL_strtab, str, len, NULL, hash);
2353 Can't rehash the shared string table, so not sure if it's worth
2354 counting the number of entries in the linked list
2356 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2357 /* assert(xhv_array != 0) */
2359 entry = (HvARRAY(PL_strtab))[hindex];
2360 for (;entry; entry = HeNEXT(entry)) {
2361 if (HeHASH(entry) != hash) /* strings can't be equal */
2363 if (HeKLEN(entry) != len)
2365 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2367 if (HeKFLAGS(entry) != flags_masked)
2373 /* What used to be head of the list.
2374 If this is NULL, then we're the first entry for this slot, which
2375 means we need to increate fill. */
2376 struct shared_he *new_entry;
2379 HE **const head = &HvARRAY(PL_strtab)[hindex];
2380 HE *const next = *head;
2382 /* We don't actually store a HE from the arena and a regular HEK.
2383 Instead we allocate one chunk of memory big enough for both,
2384 and put the HEK straight after the HE. This way we can find the
2385 HEK directly from the HE.
2388 Newx(k, STRUCT_OFFSET(struct shared_he,
2389 shared_he_hek.hek_key[0]) + len + 2, char);
2390 new_entry = (struct shared_he *)k;
2391 entry = &(new_entry->shared_he_he);
2392 hek = &(new_entry->shared_he_hek);
2394 Copy(str, HEK_KEY(hek), len, char);
2395 HEK_KEY(hek)[len] = 0;
2397 HEK_HASH(hek) = hash;
2398 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2400 /* Still "point" to the HEK, so that other code need not know what
2402 HeKEY_hek(entry) = hek;
2403 entry->he_valu.hent_refcount = 0;
2404 HeNEXT(entry) = next;
2407 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2408 if (!next) { /* initial entry? */
2409 xhv->xhv_fill++; /* HvFILL(hv)++ */
2410 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2415 ++entry->he_valu.hent_refcount;
2416 UNLOCK_STRTAB_MUTEX;
2418 if (flags & HVhek_FREEKEY)
2421 return HeKEY_hek(entry);
2425 Perl_hv_placeholders_p(pTHX_ HV *hv)
2428 MAGIC *mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2431 mg = sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, 0);
2434 Perl_die(aTHX_ "panic: hv_placeholders_p");
2437 return &(mg->mg_len);
2442 Perl_hv_placeholders_get(pTHX_ HV *hv)
2445 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2447 return mg ? mg->mg_len : 0;
2451 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2454 MAGIC * const mg = mg_find((SV*)hv, PERL_MAGIC_rhash);
2459 if (!sv_magicext((SV*)hv, 0, PERL_MAGIC_rhash, 0, 0, ph))
2460 Perl_die(aTHX_ "panic: hv_placeholders_set");
2462 /* else we don't need to add magic to record 0 placeholders. */
2466 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2470 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2475 value = &PL_sv_placeholder;
2478 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2481 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2484 case HVrhek_PV_UTF8:
2485 /* Create a string SV that directly points to the bytes in our
2487 value = newSV_type(SVt_PV);
2488 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2489 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2490 /* This stops anything trying to free it */
2491 SvLEN_set(value, 0);
2493 SvREADONLY_on(value);
2494 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2498 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2499 he->refcounted_he_data[0]);
2505 =for apidoc refcounted_he_chain_2hv
2507 Generates and returns a C<HV *> by walking up the tree starting at the passed
2508 in C<struct refcounted_he *>.
2513 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2517 U32 placeholders = 0;
2518 /* We could chase the chain once to get an idea of the number of keys,
2519 and call ksplit. But for now we'll make a potentially inefficient
2520 hash with only 8 entries in its array. */
2521 const U32 max = HvMAX(hv);
2525 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2526 HvARRAY(hv) = (HE**)array;
2531 U32 hash = chain->refcounted_he_hash;
2533 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2535 HE **oentry = &((HvARRAY(hv))[hash & max]);
2536 HE *entry = *oentry;
2539 for (; entry; entry = HeNEXT(entry)) {
2540 if (HeHASH(entry) == hash) {
2541 /* We might have a duplicate key here. If so, entry is older
2542 than the key we've already put in the hash, so if they are
2543 the same, skip adding entry. */
2545 const STRLEN klen = HeKLEN(entry);
2546 const char *const key = HeKEY(entry);
2547 if (klen == chain->refcounted_he_keylen
2548 && (!!HeKUTF8(entry)
2549 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2550 && memEQ(key, REF_HE_KEY(chain), klen))
2553 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2555 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2556 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2557 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2568 = share_hek_flags(REF_HE_KEY(chain),
2569 chain->refcounted_he_keylen,
2570 chain->refcounted_he_hash,
2571 (chain->refcounted_he_data[0]
2572 & (HVhek_UTF8|HVhek_WASUTF8)));
2574 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2576 value = refcounted_he_value(chain);
2577 if (value == &PL_sv_placeholder)
2579 HeVAL(entry) = value;
2581 /* Link it into the chain. */
2582 HeNEXT(entry) = *oentry;
2583 if (!HeNEXT(entry)) {
2584 /* initial entry. */
2592 chain = chain->refcounted_he_next;
2596 clear_placeholders(hv, placeholders);
2597 HvTOTALKEYS(hv) -= placeholders;
2600 /* We could check in the loop to see if we encounter any keys with key
2601 flags, but it's probably not worth it, as this per-hash flag is only
2602 really meant as an optimisation for things like Storable. */
2604 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2610 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2611 const char *key, STRLEN klen, int flags, U32 hash)
2614 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2615 of your key has to exactly match that which is stored. */
2616 SV *value = &PL_sv_placeholder;
2620 if (flags & HVhek_FREEKEY)
2622 key = SvPV_const(keysv, klen);
2624 is_utf8 = (SvUTF8(keysv) != 0);
2626 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2630 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2631 hash = SvSHARED_HASH(keysv);
2633 PERL_HASH(hash, key, klen);
2637 for (; chain; chain = chain->refcounted_he_next) {
2639 if (hash != chain->refcounted_he_hash)
2641 if (klen != chain->refcounted_he_keylen)
2643 if (memNE(REF_HE_KEY(chain),key,klen))
2645 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2648 if (hash != HEK_HASH(chain->refcounted_he_hek))
2650 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2652 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2654 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2658 value = sv_2mortal(refcounted_he_value(chain));
2662 if (flags & HVhek_FREEKEY)
2669 =for apidoc refcounted_he_new
2671 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2672 stored in a compact form, all references remain the property of the caller.
2673 The C<struct refcounted_he> is returned with a reference count of 1.
2678 struct refcounted_he *
2679 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2680 SV *const key, SV *const value) {
2682 struct refcounted_he *he;
2684 const char *key_p = SvPV_const(key, key_len);
2685 STRLEN value_len = 0;
2686 const char *value_p = NULL;
2691 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2694 value_type = HVrhek_PV;
2695 } else if (SvIOK(value)) {
2696 value_type = HVrhek_IV;
2697 } else if (value == &PL_sv_placeholder) {
2698 value_type = HVrhek_delete;
2699 } else if (!SvOK(value)) {
2700 value_type = HVrhek_undef;
2702 value_type = HVrhek_PV;
2705 if (value_type == HVrhek_PV) {
2706 value_p = SvPV_const(value, value_len);
2707 key_offset = value_len + 2;
2714 he = (struct refcounted_he*)
2715 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2719 he = (struct refcounted_he*)
2720 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2725 he->refcounted_he_next = parent;
2727 if (value_type == HVrhek_PV) {
2728 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
2729 he->refcounted_he_val.refcounted_he_u_len = value_len;
2730 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2731 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2733 value_type = HVrhek_PV_UTF8;
2734 } else if (value_type == HVrhek_IV) {
2736 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
2737 value_type = HVrhek_UV;
2739 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
2745 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2746 As we're going to be building hash keys from this value in future,
2747 normalise it now. */
2748 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2749 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2751 PERL_HASH(hash, key_p, key_len);
2754 he->refcounted_he_hash = hash;
2755 he->refcounted_he_keylen = key_len;
2756 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2758 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2761 if (flags & HVhek_WASUTF8) {
2762 /* If it was downgraded from UTF-8, then the pointer returned from
2763 bytes_from_utf8 is an allocated pointer that we must free. */
2767 he->refcounted_he_data[0] = flags;
2768 he->refcounted_he_refcnt = 1;
2774 =for apidoc refcounted_he_free
2776 Decrements the reference count of the passed in C<struct refcounted_he *>
2777 by one. If the reference count reaches zero the structure's memory is freed,
2778 and C<refcounted_he_free> iterates onto the parent node.
2784 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2786 PERL_UNUSED_CONTEXT;
2789 struct refcounted_he *copy;
2793 new_count = --he->refcounted_he_refcnt;
2794 HINTS_REFCNT_UNLOCK;
2800 #ifndef USE_ITHREADS
2801 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2804 he = he->refcounted_he_next;
2805 PerlMemShared_free(copy);
2810 =for apidoc hv_assert
2812 Check that a hash is in an internally consistent state.
2820 Perl_hv_assert(pTHX_ HV *hv)
2825 int placeholders = 0;
2828 const I32 riter = HvRITER_get(hv);
2829 HE *eiter = HvEITER_get(hv);
2831 (void)hv_iterinit(hv);
2833 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2834 /* sanity check the values */
2835 if (HeVAL(entry) == &PL_sv_placeholder)
2839 /* sanity check the keys */
2840 if (HeSVKEY(entry)) {
2841 NOOP; /* Don't know what to check on SV keys. */
2842 } else if (HeKUTF8(entry)) {
2844 if (HeKWASUTF8(entry)) {
2845 PerlIO_printf(Perl_debug_log,
2846 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2847 (int) HeKLEN(entry), HeKEY(entry));
2850 } else if (HeKWASUTF8(entry))
2853 if (!SvTIED_mg((SV*)hv, PERL_MAGIC_tied)) {
2854 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2855 const int nhashkeys = HvUSEDKEYS(hv);
2856 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
2858 if (nhashkeys != real) {
2859 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
2862 if (nhashplaceholders != placeholders) {
2863 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
2867 if (withflags && ! HvHASKFLAGS(hv)) {
2868 PerlIO_printf(Perl_debug_log,
2869 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
2876 HvRITER_set(hv, riter); /* Restore hash iterator state */
2877 HvEITER_set(hv, eiter);
2884 * c-indentation-style: bsd
2886 * indent-tabs-mode: t
2889 * ex: set ts=8 sts=4 sw=4 noet: