3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
22 A HV structure represents a Perl hash. It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures. The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value. Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
35 #define PERL_HASH_INTERNAL_ACCESS
38 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
47 /* We could generate this at compile time via (another) auxiliary C
49 const size_t arena_size = Perl_malloc_good_size(PERL_ARENA_SIZE);
50 HE* he = (HE*) Perl_get_arena(aTHX_ arena_size, HE_SVSLOT);
51 HE * const heend = &he[arena_size / sizeof(HE) - 1];
53 PL_body_roots[HE_SVSLOT] = he;
55 HeNEXT(he) = (HE*)(he + 1);
63 #define new_HE() (HE*)safemalloc(sizeof(HE))
64 #define del_HE(p) safefree((char*)p)
73 void ** const root = &PL_body_roots[HE_SVSLOT];
83 #define new_HE() new_he()
86 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
87 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
103 Newx(k, HEK_BASESIZE + len + 2, char);
105 Copy(str, HEK_KEY(hek), len, char);
106 HEK_KEY(hek)[len] = 0;
108 HEK_HASH(hek) = hash;
109 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
111 if (flags & HVhek_FREEKEY)
116 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
120 Perl_free_tied_hv_pool(pTHX)
123 HE *he = PL_hv_fetch_ent_mh;
126 Safefree(HeKEY_hek(he));
130 PL_hv_fetch_ent_mh = NULL;
133 #if defined(USE_ITHREADS)
135 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
137 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
139 PERL_ARGS_ASSERT_HEK_DUP;
140 PERL_UNUSED_ARG(param);
143 /* We already shared this hash key. */
144 (void)share_hek_hek(shared);
148 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
149 HEK_HASH(source), HEK_FLAGS(source));
150 ptr_table_store(PL_ptr_table, source, shared);
156 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
160 PERL_ARGS_ASSERT_HE_DUP;
164 /* look for it in the table first */
165 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
169 /* create anew and remember what it is */
171 ptr_table_store(PL_ptr_table, e, ret);
173 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
174 if (HeKLEN(e) == HEf_SVKEY) {
176 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
177 HeKEY_hek(ret) = (HEK*)k;
178 HeKEY_sv(ret) = SvREFCNT_inc(sv_dup(HeKEY_sv(e), param));
181 /* This is hek_dup inlined, which seems to be important for speed
183 HEK * const source = HeKEY_hek(e);
184 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
187 /* We already shared this hash key. */
188 (void)share_hek_hek(shared);
192 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
193 HEK_HASH(source), HEK_FLAGS(source));
194 ptr_table_store(PL_ptr_table, source, shared);
196 HeKEY_hek(ret) = shared;
199 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
201 HeVAL(ret) = SvREFCNT_inc(sv_dup(HeVAL(e), param));
204 #endif /* USE_ITHREADS */
207 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
210 SV * const sv = sv_newmortal();
212 PERL_ARGS_ASSERT_HV_NOTALLOWED;
214 if (!(flags & HVhek_FREEKEY)) {
215 sv_setpvn(sv, key, klen);
218 /* Need to free saved eventually assign to mortal SV */
219 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
220 sv_usepvn(sv, (char *) key, klen);
222 if (flags & HVhek_UTF8) {
225 Perl_croak(aTHX_ msg, SVfARG(sv));
228 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
234 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
235 the length of the key. The C<hash> parameter is the precomputed hash
236 value; if it is zero then Perl will compute it. The return value will be
237 NULL if the operation failed or if the value did not need to be actually
238 stored within the hash (as in the case of tied hashes). Otherwise it can
239 be dereferenced to get the original C<SV*>. Note that the caller is
240 responsible for suitably incrementing the reference count of C<val> before
241 the call, and decrementing it if the function returned NULL. Effectively
242 a successful hv_store takes ownership of one reference to C<val>. This is
243 usually what you want; a newly created SV has a reference count of one, so
244 if all your code does is create SVs then store them in a hash, hv_store
245 will own the only reference to the new SV, and your code doesn't need to do
246 anything further to tidy up. hv_store is not implemented as a call to
247 hv_store_ent, and does not create a temporary SV for the key, so if your
248 key data is not already in SV form then use hv_store in preference to
251 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
252 information on how to use this function on tied hashes.
254 =for apidoc hv_store_ent
256 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
257 parameter is the precomputed hash value; if it is zero then Perl will
258 compute it. The return value is the new hash entry so created. It will be
259 NULL if the operation failed or if the value did not need to be actually
260 stored within the hash (as in the case of tied hashes). Otherwise the
261 contents of the return value can be accessed using the C<He?> macros
262 described here. Note that the caller is responsible for suitably
263 incrementing the reference count of C<val> before the call, and
264 decrementing it if the function returned NULL. Effectively a successful
265 hv_store_ent takes ownership of one reference to C<val>. This is
266 usually what you want; a newly created SV has a reference count of one, so
267 if all your code does is create SVs then store them in a hash, hv_store
268 will own the only reference to the new SV, and your code doesn't need to do
269 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
270 unlike C<val> it does not take ownership of it, so maintaining the correct
271 reference count on C<key> is entirely the caller's responsibility. hv_store
272 is not implemented as a call to hv_store_ent, and does not create a temporary
273 SV for the key, so if your key data is not already in SV form then use
274 hv_store in preference to hv_store_ent.
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
281 Returns a boolean indicating whether the specified hash key exists. The
282 C<klen> is the length of the key.
286 Returns the SV which corresponds to the specified key in the hash. The
287 C<klen> is the length of the key. If C<lval> is set then the fetch will be
288 part of a store. Check that the return value is non-null before
289 dereferencing it to an C<SV*>.
291 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
292 information on how to use this function on tied hashes.
294 =for apidoc hv_exists_ent
296 Returns a boolean indicating whether the specified hash key exists. C<hash>
297 can be a valid precomputed hash value, or 0 to ask for it to be
303 /* returns an HE * structure with the all fields set */
304 /* note that hent_val will be a mortal sv for MAGICAL hashes */
306 =for apidoc hv_fetch_ent
308 Returns the hash entry which corresponds to the specified key in the hash.
309 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
310 if you want the function to compute it. IF C<lval> is set then the fetch
311 will be part of a store. Make sure the return value is non-null before
312 accessing it. The return value when C<tb> is a tied hash is a pointer to a
313 static location, so be sure to make a copy of the structure if you need to
316 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
317 information on how to use this function on tied hashes.
322 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
324 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
325 const int action, SV *val, const U32 hash)
330 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
339 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
343 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
344 int flags, int action, SV *val, register U32 hash)
353 const int return_svp = action & HV_FETCH_JUST_SV;
357 if (SvTYPE(hv) == SVTYPEMASK)
360 assert(SvTYPE(hv) == SVt_PVHV);
362 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
364 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
365 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
366 if (uf->uf_set == NULL) {
367 SV* obj = mg->mg_obj;
370 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
371 ((flags & HVhek_UTF8)
375 mg->mg_obj = keysv; /* pass key */
376 uf->uf_index = action; /* pass action */
377 magic_getuvar(MUTABLE_SV(hv), mg);
378 keysv = mg->mg_obj; /* may have changed */
381 /* If the key may have changed, then we need to invalidate
382 any passed-in computed hash value. */
388 if (flags & HVhek_FREEKEY)
390 key = SvPV_const(keysv, klen);
392 is_utf8 = (SvUTF8(keysv) != 0);
394 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
397 if (action & HV_DELETE) {
398 return (void *) hv_delete_common(hv, keysv, key, klen,
399 flags | (is_utf8 ? HVhek_UTF8 : 0),
403 xhv = (XPVHV*)SvANY(hv);
405 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
406 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
407 || SvGMAGICAL((const SV *)hv))
409 /* FIXME should be able to skimp on the HE/HEK here when
410 HV_FETCH_JUST_SV is true. */
412 keysv = newSVpvn_utf8(key, klen, is_utf8);
414 keysv = newSVsv(keysv);
417 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
419 /* grab a fake HE/HEK pair from the pool or make a new one */
420 entry = PL_hv_fetch_ent_mh;
422 PL_hv_fetch_ent_mh = HeNEXT(entry);
426 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
427 HeKEY_hek(entry) = (HEK*)k;
429 HeNEXT(entry) = NULL;
430 HeSVKEY_set(entry, keysv);
432 sv_upgrade(sv, SVt_PVLV);
434 /* so we can free entry when freeing sv */
435 LvTARG(sv) = MUTABLE_SV(entry);
437 /* XXX remove at some point? */
438 if (flags & HVhek_FREEKEY)
442 return entry ? (void *) &HeVAL(entry) : NULL;
444 return (void *) entry;
446 #ifdef ENV_IS_CASELESS
447 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
449 for (i = 0; i < klen; ++i)
450 if (isLOWER(key[i])) {
451 /* Would be nice if we had a routine to do the
452 copy and upercase in a single pass through. */
453 const char * const nkey = strupr(savepvn(key,klen));
454 /* Note that this fetch is for nkey (the uppercased
455 key) whereas the store is for key (the original) */
456 void *result = hv_common(hv, NULL, nkey, klen,
457 HVhek_FREEKEY, /* free nkey */
458 0 /* non-LVAL fetch */
459 | HV_DISABLE_UVAR_XKEY
462 0 /* compute hash */);
463 if (!result && (action & HV_FETCH_LVALUE)) {
464 /* This call will free key if necessary.
465 Do it this way to encourage compiler to tail
467 result = hv_common(hv, keysv, key, klen, flags,
469 | HV_DISABLE_UVAR_XKEY
473 if (flags & HVhek_FREEKEY)
481 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
482 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
483 || SvGMAGICAL((const SV *)hv)) {
484 /* I don't understand why hv_exists_ent has svret and sv,
485 whereas hv_exists only had one. */
486 SV * const svret = sv_newmortal();
489 if (keysv || is_utf8) {
491 keysv = newSVpvn_utf8(key, klen, TRUE);
493 keysv = newSVsv(keysv);
495 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
497 mg_copy(MUTABLE_SV(hv), sv, key, klen);
499 if (flags & HVhek_FREEKEY)
501 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
502 /* This cast somewhat evil, but I'm merely using NULL/
503 not NULL to return the boolean exists.
504 And I know hv is not NULL. */
505 return SvTRUE(svret) ? (void *)hv : NULL;
507 #ifdef ENV_IS_CASELESS
508 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
509 /* XXX This code isn't UTF8 clean. */
510 char * const keysave = (char * const)key;
511 /* Will need to free this, so set FREEKEY flag. */
512 key = savepvn(key,klen);
513 key = (const char*)strupr((char*)key);
518 if (flags & HVhek_FREEKEY) {
521 flags |= HVhek_FREEKEY;
525 else if (action & HV_FETCH_ISSTORE) {
528 hv_magic_check (hv, &needs_copy, &needs_store);
530 const bool save_taint = PL_tainted;
531 if (keysv || is_utf8) {
533 keysv = newSVpvn_utf8(key, klen, TRUE);
536 PL_tainted = SvTAINTED(keysv);
537 keysv = sv_2mortal(newSVsv(keysv));
538 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
540 mg_copy(MUTABLE_SV(hv), val, key, klen);
543 TAINT_IF(save_taint);
545 if (flags & HVhek_FREEKEY)
549 #ifdef ENV_IS_CASELESS
550 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
551 /* XXX This code isn't UTF8 clean. */
552 const char *keysave = key;
553 /* Will need to free this, so set FREEKEY flag. */
554 key = savepvn(key,klen);
555 key = (const char*)strupr((char*)key);
560 if (flags & HVhek_FREEKEY) {
563 flags |= HVhek_FREEKEY;
571 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
572 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
573 || (SvRMAGICAL((const SV *)hv)
574 && mg_find((const SV *)hv, PERL_MAGIC_env))
579 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
581 HvARRAY(hv) = (HE**)array;
583 #ifdef DYNAMIC_ENV_FETCH
584 else if (action & HV_FETCH_ISEXISTS) {
585 /* for an %ENV exists, if we do an insert it's by a recursive
586 store call, so avoid creating HvARRAY(hv) right now. */
590 /* XXX remove at some point? */
591 if (flags & HVhek_FREEKEY)
599 char * const keysave = (char *)key;
600 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
604 flags &= ~HVhek_UTF8;
605 if (key != keysave) {
606 if (flags & HVhek_FREEKEY)
608 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
613 PERL_HASH_INTERNAL(hash, key, klen);
614 /* We don't have a pointer to the hv, so we have to replicate the
615 flag into every HEK, so that hv_iterkeysv can see it. */
616 /* And yes, you do need this even though you are not "storing" because
617 you can flip the flags below if doing an lval lookup. (And that
618 was put in to give the semantics Andreas was expecting.) */
619 flags |= HVhek_REHASH;
621 if (keysv && (SvIsCOW_shared_hash(keysv))) {
622 hash = SvSHARED_HASH(keysv);
624 PERL_HASH(hash, key, klen);
628 masked_flags = (flags & HVhek_MASK);
630 #ifdef DYNAMIC_ENV_FETCH
631 if (!HvARRAY(hv)) entry = NULL;
635 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
637 for (; entry; entry = HeNEXT(entry)) {
638 if (HeHASH(entry) != hash) /* strings can't be equal */
640 if (HeKLEN(entry) != (I32)klen)
642 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
644 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
647 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
648 if (HeKFLAGS(entry) != masked_flags) {
649 /* We match if HVhek_UTF8 bit in our flags and hash key's
650 match. But if entry was set previously with HVhek_WASUTF8
651 and key now doesn't (or vice versa) then we should change
652 the key's flag, as this is assignment. */
653 if (HvSHAREKEYS(hv)) {
654 /* Need to swap the key we have for a key with the flags we
655 need. As keys are shared we can't just write to the
656 flag, so we share the new one, unshare the old one. */
657 HEK * const new_hek = share_hek_flags(key, klen, hash,
659 unshare_hek (HeKEY_hek(entry));
660 HeKEY_hek(entry) = new_hek;
662 else if (hv == PL_strtab) {
663 /* PL_strtab is usually the only hash without HvSHAREKEYS,
664 so putting this test here is cheap */
665 if (flags & HVhek_FREEKEY)
667 Perl_croak(aTHX_ S_strtab_error,
668 action & HV_FETCH_LVALUE ? "fetch" : "store");
671 HeKFLAGS(entry) = masked_flags;
672 if (masked_flags & HVhek_ENABLEHVKFLAGS)
675 if (HeVAL(entry) == &PL_sv_placeholder) {
676 /* yes, can store into placeholder slot */
677 if (action & HV_FETCH_LVALUE) {
679 /* This preserves behaviour with the old hv_fetch
680 implementation which at this point would bail out
681 with a break; (at "if we find a placeholder, we
682 pretend we haven't found anything")
684 That break mean that if a placeholder were found, it
685 caused a call into hv_store, which in turn would
686 check magic, and if there is no magic end up pretty
687 much back at this point (in hv_store's code). */
690 /* LVAL fetch which actaully needs a store. */
692 HvPLACEHOLDERS(hv)--;
695 if (val != &PL_sv_placeholder)
696 HvPLACEHOLDERS(hv)--;
699 } else if (action & HV_FETCH_ISSTORE) {
700 SvREFCNT_dec(HeVAL(entry));
703 } else if (HeVAL(entry) == &PL_sv_placeholder) {
704 /* if we find a placeholder, we pretend we haven't found
708 if (flags & HVhek_FREEKEY)
711 return entry ? (void *) &HeVAL(entry) : NULL;
715 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
716 if (!(action & HV_FETCH_ISSTORE)
717 && SvRMAGICAL((const SV *)hv)
718 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
720 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
722 sv = newSVpvn(env,len);
724 return hv_common(hv, keysv, key, klen, flags,
725 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
731 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
732 hv_notallowed(flags, key, klen,
733 "Attempt to access disallowed key '%"SVf"' in"
734 " a restricted hash");
736 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
737 /* Not doing some form of store, so return failure. */
738 if (flags & HVhek_FREEKEY)
742 if (action & HV_FETCH_LVALUE) {
745 /* At this point the old hv_fetch code would call to hv_store,
746 which in turn might do some tied magic. So we need to make that
747 magic check happen. */
748 /* gonna assign to this, so it better be there */
749 /* If a fetch-as-store fails on the fetch, then the action is to
750 recurse once into "hv_store". If we didn't do this, then that
751 recursive call would call the key conversion routine again.
752 However, as we replace the original key with the converted
753 key, this would result in a double conversion, which would show
754 up as a bug if the conversion routine is not idempotent. */
755 return hv_common(hv, keysv, key, klen, flags,
756 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
758 /* XXX Surely that could leak if the fetch-was-store fails?
759 Just like the hv_fetch. */
763 /* Welcome to hv_store... */
766 /* Not sure if we can get here. I think the only case of oentry being
767 NULL is for %ENV with dynamic env fetch. But that should disappear
768 with magic in the previous code. */
771 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
773 HvARRAY(hv) = (HE**)array;
776 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
779 /* share_hek_flags will do the free for us. This might be considered
782 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
783 else if (hv == PL_strtab) {
784 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
785 this test here is cheap */
786 if (flags & HVhek_FREEKEY)
788 Perl_croak(aTHX_ S_strtab_error,
789 action & HV_FETCH_LVALUE ? "fetch" : "store");
791 else /* gotta do the real thing */
792 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
794 HeNEXT(entry) = *oentry;
797 if (val == &PL_sv_placeholder)
798 HvPLACEHOLDERS(hv)++;
799 if (masked_flags & HVhek_ENABLEHVKFLAGS)
803 const HE *counter = HeNEXT(entry);
805 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
806 if (!counter) { /* initial entry? */
807 xhv->xhv_fill++; /* HvFILL(hv)++ */
808 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
810 } else if(!HvREHASH(hv)) {
813 while ((counter = HeNEXT(counter)))
816 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
817 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
818 bucket splits on a rehashed hash, as we're not going to
819 split it again, and if someone is lucky (evil) enough to
820 get all the keys in one list they could exhaust our memory
821 as we repeatedly double the number of buckets on every
822 entry. Linear search feels a less worse thing to do. */
829 return entry ? (void *) &HeVAL(entry) : NULL;
831 return (void *) entry;
835 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
837 const MAGIC *mg = SvMAGIC(hv);
839 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
844 if (isUPPER(mg->mg_type)) {
846 if (mg->mg_type == PERL_MAGIC_tied) {
847 *needs_store = FALSE;
848 return; /* We've set all there is to set. */
851 mg = mg->mg_moremagic;
856 =for apidoc hv_scalar
858 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
864 Perl_hv_scalar(pTHX_ HV *hv)
868 PERL_ARGS_ASSERT_HV_SCALAR;
870 if (SvRMAGICAL(hv)) {
871 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
873 return magic_scalarpack(hv, mg);
877 if (HvFILL((const HV *)hv))
878 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
879 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
887 =for apidoc hv_delete
889 Deletes a key/value pair in the hash. The value SV is removed from the
890 hash and returned to the caller. The C<klen> is the length of the key.
891 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
894 =for apidoc hv_delete_ent
896 Deletes a key/value pair in the hash. The value SV is removed from the
897 hash and returned to the caller. The C<flags> value will normally be zero;
898 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
899 precomputed hash value, or 0 to ask for it to be computed.
905 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
906 int k_flags, I32 d_flags, U32 hash)
911 register HE **oentry;
912 HE *const *first_entry;
913 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
916 if (SvRMAGICAL(hv)) {
919 hv_magic_check (hv, &needs_copy, &needs_store);
923 entry = (HE *) hv_common(hv, keysv, key, klen,
924 k_flags & ~HVhek_FREEKEY,
925 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
927 sv = entry ? HeVAL(entry) : NULL;
933 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
934 /* No longer an element */
935 sv_unmagic(sv, PERL_MAGIC_tiedelem);
938 return NULL; /* element cannot be deleted */
940 #ifdef ENV_IS_CASELESS
941 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
942 /* XXX This code isn't UTF8 clean. */
943 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
944 if (k_flags & HVhek_FREEKEY) {
947 key = strupr(SvPVX(keysv));
956 xhv = (XPVHV*)SvANY(hv);
961 const char * const keysave = key;
962 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
965 k_flags |= HVhek_UTF8;
967 k_flags &= ~HVhek_UTF8;
968 if (key != keysave) {
969 if (k_flags & HVhek_FREEKEY) {
970 /* This shouldn't happen if our caller does what we expect,
971 but strictly the API allows it. */
974 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
976 HvHASKFLAGS_on(MUTABLE_SV(hv));
980 PERL_HASH_INTERNAL(hash, key, klen);
982 if (keysv && (SvIsCOW_shared_hash(keysv))) {
983 hash = SvSHARED_HASH(keysv);
985 PERL_HASH(hash, key, klen);
989 masked_flags = (k_flags & HVhek_MASK);
991 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
993 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
995 if (HeHASH(entry) != hash) /* strings can't be equal */
997 if (HeKLEN(entry) != (I32)klen)
999 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1001 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1004 if (hv == PL_strtab) {
1005 if (k_flags & HVhek_FREEKEY)
1007 Perl_croak(aTHX_ S_strtab_error, "delete");
1010 /* if placeholder is here, it's already been deleted.... */
1011 if (HeVAL(entry) == &PL_sv_placeholder) {
1012 if (k_flags & HVhek_FREEKEY)
1016 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1017 hv_notallowed(k_flags, key, klen,
1018 "Attempt to delete readonly key '%"SVf"' from"
1019 " a restricted hash");
1021 if (k_flags & HVhek_FREEKEY)
1024 if (d_flags & G_DISCARD)
1027 sv = sv_2mortal(HeVAL(entry));
1028 HeVAL(entry) = &PL_sv_placeholder;
1032 * If a restricted hash, rather than really deleting the entry, put
1033 * a placeholder there. This marks the key as being "approved", so
1034 * we can still access via not-really-existing key without raising
1037 if (SvREADONLY(hv)) {
1038 SvREFCNT_dec(HeVAL(entry));
1039 HeVAL(entry) = &PL_sv_placeholder;
1040 /* We'll be saving this slot, so the number of allocated keys
1041 * doesn't go down, but the number placeholders goes up */
1042 HvPLACEHOLDERS(hv)++;
1044 *oentry = HeNEXT(entry);
1046 xhv->xhv_fill--; /* HvFILL(hv)-- */
1048 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1051 hv_free_ent(hv, entry);
1052 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1053 if (xhv->xhv_keys == 0)
1054 HvHASKFLAGS_off(hv);
1058 if (SvREADONLY(hv)) {
1059 hv_notallowed(k_flags, key, klen,
1060 "Attempt to delete disallowed key '%"SVf"' from"
1061 " a restricted hash");
1064 if (k_flags & HVhek_FREEKEY)
1070 S_hsplit(pTHX_ HV *hv)
1073 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1074 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1075 register I32 newsize = oldsize * 2;
1077 char *a = (char*) HvARRAY(hv);
1079 register HE **oentry;
1080 int longest_chain = 0;
1083 PERL_ARGS_ASSERT_HSPLIT;
1085 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1086 (void*)hv, (int) oldsize);*/
1088 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1089 /* Can make this clear any placeholders first for non-restricted hashes,
1090 even though Storable rebuilds restricted hashes by putting in all the
1091 placeholders (first) before turning on the readonly flag, because
1092 Storable always pre-splits the hash. */
1093 hv_clear_placeholders(hv);
1097 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1098 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1099 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1105 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1108 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1109 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1114 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1116 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1118 if (oldsize >= 64) {
1119 offer_nice_chunk(HvARRAY(hv),
1120 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1121 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1124 Safefree(HvARRAY(hv));
1128 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1129 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1130 HvARRAY(hv) = (HE**) a;
1133 for (i=0; i<oldsize; i++,aep++) {
1134 int left_length = 0;
1135 int right_length = 0;
1139 if (!*aep) /* non-existent */
1142 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1143 if ((HeHASH(entry) & newsize) != (U32)i) {
1144 *oentry = HeNEXT(entry);
1145 HeNEXT(entry) = *bep;
1147 xhv->xhv_fill++; /* HvFILL(hv)++ */
1153 oentry = &HeNEXT(entry);
1157 if (!*aep) /* everything moved */
1158 xhv->xhv_fill--; /* HvFILL(hv)-- */
1159 /* I think we don't actually need to keep track of the longest length,
1160 merely flag if anything is too long. But for the moment while
1161 developing this code I'll track it. */
1162 if (left_length > longest_chain)
1163 longest_chain = left_length;
1164 if (right_length > longest_chain)
1165 longest_chain = right_length;
1169 /* Pick your policy for "hashing isn't working" here: */
1170 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1175 if (hv == PL_strtab) {
1176 /* Urg. Someone is doing something nasty to the string table.
1181 /* Awooga. Awooga. Pathological data. */
1182 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1183 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1186 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1187 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1189 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1192 was_shared = HvSHAREKEYS(hv);
1195 HvSHAREKEYS_off(hv);
1200 for (i=0; i<newsize; i++,aep++) {
1201 register HE *entry = *aep;
1203 /* We're going to trash this HE's next pointer when we chain it
1204 into the new hash below, so store where we go next. */
1205 HE * const next = HeNEXT(entry);
1210 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1215 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1216 hash, HeKFLAGS(entry));
1217 unshare_hek (HeKEY_hek(entry));
1218 HeKEY_hek(entry) = new_hek;
1220 /* Not shared, so simply write the new hash in. */
1221 HeHASH(entry) = hash;
1223 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1224 HEK_REHASH_on(HeKEY_hek(entry));
1225 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1227 /* Copy oentry to the correct new chain. */
1228 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1230 xhv->xhv_fill++; /* HvFILL(hv)++ */
1231 HeNEXT(entry) = *bep;
1237 Safefree (HvARRAY(hv));
1238 HvARRAY(hv) = (HE **)a;
1242 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1245 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1246 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1247 register I32 newsize;
1252 register HE **oentry;
1254 PERL_ARGS_ASSERT_HV_KSPLIT;
1256 newsize = (I32) newmax; /* possible truncation here */
1257 if (newsize != newmax || newmax <= oldsize)
1259 while ((newsize & (1 + ~newsize)) != newsize) {
1260 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1262 if (newsize < newmax)
1264 if (newsize < newmax)
1265 return; /* overflow detection */
1267 a = (char *) HvARRAY(hv);
1270 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1271 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1272 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1278 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1281 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1282 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1287 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1289 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1291 if (oldsize >= 64) {
1292 offer_nice_chunk(HvARRAY(hv),
1293 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1294 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1297 Safefree(HvARRAY(hv));
1300 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1303 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1305 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1306 HvARRAY(hv) = (HE **) a;
1307 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1311 for (i=0; i<oldsize; i++,aep++) {
1312 if (!*aep) /* non-existent */
1314 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1315 register I32 j = (HeHASH(entry) & newsize);
1319 *oentry = HeNEXT(entry);
1320 if (!(HeNEXT(entry) = aep[j]))
1321 xhv->xhv_fill++; /* HvFILL(hv)++ */
1326 oentry = &HeNEXT(entry);
1328 if (!*aep) /* everything moved */
1329 xhv->xhv_fill--; /* HvFILL(hv)-- */
1334 Perl_newHVhv(pTHX_ HV *ohv)
1336 HV * const hv = newHV();
1337 STRLEN hv_max, hv_fill;
1339 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1341 hv_max = HvMAX(ohv);
1343 if (!SvMAGICAL((const SV *)ohv)) {
1344 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1346 const bool shared = !!HvSHAREKEYS(ohv);
1347 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1349 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1352 /* In each bucket... */
1353 for (i = 0; i <= hv_max; i++) {
1355 HE *oent = oents[i];
1362 /* Copy the linked list of entries. */
1363 for (; oent; oent = HeNEXT(oent)) {
1364 const U32 hash = HeHASH(oent);
1365 const char * const key = HeKEY(oent);
1366 const STRLEN len = HeKLEN(oent);
1367 const int flags = HeKFLAGS(oent);
1368 HE * const ent = new_HE();
1370 HeVAL(ent) = newSVsv(HeVAL(oent));
1372 = shared ? share_hek_flags(key, len, hash, flags)
1373 : save_hek_flags(key, len, hash, flags);
1384 HvFILL(hv) = hv_fill;
1385 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1389 /* Iterate over ohv, copying keys and values one at a time. */
1391 const I32 riter = HvRITER_get(ohv);
1392 HE * const eiter = HvEITER_get(ohv);
1394 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1395 while (hv_max && hv_max + 1 >= hv_fill * 2)
1396 hv_max = hv_max / 2;
1400 while ((entry = hv_iternext_flags(ohv, 0))) {
1401 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1402 newSVsv(HeVAL(entry)), HeHASH(entry),
1405 HvRITER_set(ohv, riter);
1406 HvEITER_set(ohv, eiter);
1412 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1413 magic stays on it. */
1415 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1417 HV * const hv = newHV();
1420 if (ohv && (hv_fill = HvFILL(ohv))) {
1421 STRLEN hv_max = HvMAX(ohv);
1423 const I32 riter = HvRITER_get(ohv);
1424 HE * const eiter = HvEITER_get(ohv);
1426 while (hv_max && hv_max + 1 >= hv_fill * 2)
1427 hv_max = hv_max / 2;
1431 while ((entry = hv_iternext_flags(ohv, 0))) {
1432 SV *const sv = newSVsv(HeVAL(entry));
1433 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1434 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1435 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1436 sv, HeHASH(entry), HeKFLAGS(entry));
1438 HvRITER_set(ohv, riter);
1439 HvEITER_set(ohv, eiter);
1441 hv_magic(hv, NULL, PERL_MAGIC_hints);
1446 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1451 PERL_ARGS_ASSERT_HV_FREE_ENT;
1456 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1457 mro_method_changed_in(hv); /* deletion of method from stash */
1459 if (HeKLEN(entry) == HEf_SVKEY) {
1460 SvREFCNT_dec(HeKEY_sv(entry));
1461 Safefree(HeKEY_hek(entry));
1463 else if (HvSHAREKEYS(hv))
1464 unshare_hek(HeKEY_hek(entry));
1466 Safefree(HeKEY_hek(entry));
1471 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1475 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1479 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1480 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1481 if (HeKLEN(entry) == HEf_SVKEY) {
1482 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1484 hv_free_ent(hv, entry);
1488 =for apidoc hv_clear
1490 Clears a hash, making it empty.
1496 Perl_hv_clear(pTHX_ HV *hv)
1499 register XPVHV* xhv;
1503 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1505 xhv = (XPVHV*)SvANY(hv);
1507 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1508 /* restricted hash: convert all keys to placeholders */
1510 for (i = 0; i <= xhv->xhv_max; i++) {
1511 HE *entry = (HvARRAY(hv))[i];
1512 for (; entry; entry = HeNEXT(entry)) {
1513 /* not already placeholder */
1514 if (HeVAL(entry) != &PL_sv_placeholder) {
1515 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1516 SV* const keysv = hv_iterkeysv(entry);
1518 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1521 SvREFCNT_dec(HeVAL(entry));
1522 HeVAL(entry) = &PL_sv_placeholder;
1523 HvPLACEHOLDERS(hv)++;
1531 HvPLACEHOLDERS_set(hv, 0);
1533 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1536 mg_clear(MUTABLE_SV(hv));
1538 HvHASKFLAGS_off(hv);
1543 mro_isa_changed_in(hv);
1544 HvEITER_set(hv, NULL);
1549 =for apidoc hv_clear_placeholders
1551 Clears any placeholders from a hash. If a restricted hash has any of its keys
1552 marked as readonly and the key is subsequently deleted, the key is not actually
1553 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1554 it so it will be ignored by future operations such as iterating over the hash,
1555 but will still allow the hash to have a value reassigned to the key at some
1556 future point. This function clears any such placeholder keys from the hash.
1557 See Hash::Util::lock_keys() for an example of its use.
1563 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1566 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1568 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1571 clear_placeholders(hv, items);
1575 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1580 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1587 /* Loop down the linked list heads */
1589 HE **oentry = &(HvARRAY(hv))[i];
1592 while ((entry = *oentry)) {
1593 if (HeVAL(entry) == &PL_sv_placeholder) {
1594 *oentry = HeNEXT(entry);
1595 if (first && !*oentry)
1596 HvFILL(hv)--; /* This linked list is now empty. */
1597 if (entry == HvEITER_get(hv))
1600 hv_free_ent(hv, entry);
1604 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1605 if (HvKEYS(hv) == 0)
1606 HvHASKFLAGS_off(hv);
1607 HvPLACEHOLDERS_set(hv, 0);
1611 oentry = &HeNEXT(entry);
1616 /* You can't get here, hence assertion should always fail. */
1617 assert (items == 0);
1622 S_hfreeentries(pTHX_ HV *hv)
1624 /* This is the array that we're going to restore */
1625 HE **const orig_array = HvARRAY(hv);
1629 PERL_ARGS_ASSERT_HFREEENTRIES;
1635 /* If the hash is actually a symbol table with a name, look after the
1637 struct xpvhv_aux *iter = HvAUX(hv);
1639 name = iter->xhv_name;
1640 iter->xhv_name = NULL;
1645 /* orig_array remains unchanged throughout the loop. If after freeing all
1646 the entries it turns out that one of the little blighters has triggered
1647 an action that has caused HvARRAY to be re-allocated, then we set
1648 array to the new HvARRAY, and try again. */
1651 /* This is the one we're going to try to empty. First time round
1652 it's the original array. (Hopefully there will only be 1 time
1654 HE ** const array = HvARRAY(hv);
1657 /* Because we have taken xhv_name out, the only allocated pointer
1658 in the aux structure that might exist is the backreference array.
1663 struct mro_meta *meta;
1664 struct xpvhv_aux *iter = HvAUX(hv);
1665 /* If there are weak references to this HV, we need to avoid
1666 freeing them up here. In particular we need to keep the AV
1667 visible as what we're deleting might well have weak references
1668 back to this HV, so the for loop below may well trigger
1669 the removal of backreferences from this array. */
1671 if (iter->xhv_backreferences) {
1672 /* So donate them to regular backref magic to keep them safe.
1673 The sv_magic will increase the reference count of the AV,
1674 so we need to drop it first. */
1675 SvREFCNT_dec(iter->xhv_backreferences);
1676 if (AvFILLp(iter->xhv_backreferences) == -1) {
1677 /* Turns out that the array is empty. Just free it. */
1678 SvREFCNT_dec(iter->xhv_backreferences);
1681 sv_magic(MUTABLE_SV(hv),
1682 MUTABLE_SV(iter->xhv_backreferences),
1683 PERL_MAGIC_backref, NULL, 0);
1685 iter->xhv_backreferences = NULL;
1688 entry = iter->xhv_eiter; /* HvEITER(hv) */
1689 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1691 hv_free_ent(hv, entry);
1693 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1694 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1696 if((meta = iter->xhv_mro_meta)) {
1697 if(meta->mro_linear_dfs) SvREFCNT_dec(meta->mro_linear_dfs);
1698 if(meta->mro_linear_c3) SvREFCNT_dec(meta->mro_linear_c3);
1699 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1700 SvREFCNT_dec(meta->isa);
1702 iter->xhv_mro_meta = NULL;
1705 /* There are now no allocated pointers in the aux structure. */
1707 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1708 /* What aux structure? */
1711 /* make everyone else think the array is empty, so that the destructors
1712 * called for freed entries can't recusively mess with us */
1715 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1719 /* Loop down the linked list heads */
1720 HE *entry = array[i];
1723 register HE * const oentry = entry;
1724 entry = HeNEXT(entry);
1725 hv_free_ent(hv, oentry);
1729 /* As there are no allocated pointers in the aux structure, it's now
1730 safe to free the array we just cleaned up, if it's not the one we're
1731 going to put back. */
1732 if (array != orig_array) {
1737 /* Good. No-one added anything this time round. */
1742 /* Someone attempted to iterate or set the hash name while we had
1743 the array set to 0. We'll catch backferences on the next time
1744 round the while loop. */
1745 assert(HvARRAY(hv));
1747 if (HvAUX(hv)->xhv_name) {
1748 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1752 if (--attempts == 0) {
1753 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1757 HvARRAY(hv) = orig_array;
1759 /* If the hash was actually a symbol table, put the name back. */
1761 /* We have restored the original array. If name is non-NULL, then
1762 the original array had an aux structure at the end. So this is
1764 SvFLAGS(hv) |= SVf_OOK;
1765 HvAUX(hv)->xhv_name = name;
1770 =for apidoc hv_undef
1778 Perl_hv_undef(pTHX_ HV *hv)
1781 register XPVHV* xhv;
1786 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1787 xhv = (XPVHV*)SvANY(hv);
1789 if ((name = HvNAME_get(hv)) && !PL_dirty)
1790 mro_isa_changed_in(hv);
1795 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1796 hv_name_set(hv, NULL, 0, 0);
1798 SvFLAGS(hv) &= ~SVf_OOK;
1799 Safefree(HvARRAY(hv));
1800 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1802 HvPLACEHOLDERS_set(hv, 0);
1805 mg_clear(MUTABLE_SV(hv));
1808 static struct xpvhv_aux*
1809 S_hv_auxinit(HV *hv) {
1810 struct xpvhv_aux *iter;
1813 PERL_ARGS_ASSERT_HV_AUXINIT;
1816 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1817 + sizeof(struct xpvhv_aux), char);
1819 array = (char *) HvARRAY(hv);
1820 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1821 + sizeof(struct xpvhv_aux), char);
1823 HvARRAY(hv) = (HE**) array;
1824 /* SvOOK_on(hv) attacks the IV flags. */
1825 SvFLAGS(hv) |= SVf_OOK;
1828 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1829 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1831 iter->xhv_backreferences = 0;
1832 iter->xhv_mro_meta = NULL;
1837 =for apidoc hv_iterinit
1839 Prepares a starting point to traverse a hash table. Returns the number of
1840 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1841 currently only meaningful for hashes without tie magic.
1843 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1844 hash buckets that happen to be in use. If you still need that esoteric
1845 value, you can get it through the macro C<HvFILL(tb)>.
1852 Perl_hv_iterinit(pTHX_ HV *hv)
1854 PERL_ARGS_ASSERT_HV_ITERINIT;
1856 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1859 Perl_croak(aTHX_ "Bad hash");
1862 struct xpvhv_aux * const iter = HvAUX(hv);
1863 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1864 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1866 hv_free_ent(hv, entry);
1868 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1869 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1874 /* used to be xhv->xhv_fill before 5.004_65 */
1875 return HvTOTALKEYS(hv);
1879 Perl_hv_riter_p(pTHX_ HV *hv) {
1880 struct xpvhv_aux *iter;
1882 PERL_ARGS_ASSERT_HV_RITER_P;
1885 Perl_croak(aTHX_ "Bad hash");
1887 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1888 return &(iter->xhv_riter);
1892 Perl_hv_eiter_p(pTHX_ HV *hv) {
1893 struct xpvhv_aux *iter;
1895 PERL_ARGS_ASSERT_HV_EITER_P;
1898 Perl_croak(aTHX_ "Bad hash");
1900 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1901 return &(iter->xhv_eiter);
1905 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1906 struct xpvhv_aux *iter;
1908 PERL_ARGS_ASSERT_HV_RITER_SET;
1911 Perl_croak(aTHX_ "Bad hash");
1919 iter = hv_auxinit(hv);
1921 iter->xhv_riter = riter;
1925 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1926 struct xpvhv_aux *iter;
1928 PERL_ARGS_ASSERT_HV_EITER_SET;
1931 Perl_croak(aTHX_ "Bad hash");
1936 /* 0 is the default so don't go malloc()ing a new structure just to
1941 iter = hv_auxinit(hv);
1943 iter->xhv_eiter = eiter;
1947 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1950 struct xpvhv_aux *iter;
1953 PERL_ARGS_ASSERT_HV_NAME_SET;
1954 PERL_UNUSED_ARG(flags);
1957 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1961 if (iter->xhv_name) {
1962 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1968 iter = hv_auxinit(hv);
1970 PERL_HASH(hash, name, len);
1971 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1975 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1976 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1978 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
1979 PERL_UNUSED_CONTEXT;
1981 return &(iter->xhv_backreferences);
1985 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
1988 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
1993 av = HvAUX(hv)->xhv_backreferences;
1996 HvAUX(hv)->xhv_backreferences = 0;
1997 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2003 hv_iternext is implemented as a macro in hv.h
2005 =for apidoc hv_iternext
2007 Returns entries from a hash iterator. See C<hv_iterinit>.
2009 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2010 iterator currently points to, without losing your place or invalidating your
2011 iterator. Note that in this case the current entry is deleted from the hash
2012 with your iterator holding the last reference to it. Your iterator is flagged
2013 to free the entry on the next call to C<hv_iternext>, so you must not discard
2014 your iterator immediately else the entry will leak - call C<hv_iternext> to
2015 trigger the resource deallocation.
2017 =for apidoc hv_iternext_flags
2019 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2020 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2021 set the placeholders keys (for restricted hashes) will be returned in addition
2022 to normal keys. By default placeholders are automatically skipped over.
2023 Currently a placeholder is implemented with a value that is
2024 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2025 restricted hashes may change, and the implementation currently is
2026 insufficiently abstracted for any change to be tidy.
2032 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2035 register XPVHV* xhv;
2039 struct xpvhv_aux *iter;
2041 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2044 Perl_croak(aTHX_ "Bad hash");
2046 xhv = (XPVHV*)SvANY(hv);
2049 /* Too many things (well, pp_each at least) merrily assume that you can
2050 call iv_iternext without calling hv_iterinit, so we'll have to deal
2056 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2057 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2058 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2059 SV * const key = sv_newmortal();
2061 sv_setsv(key, HeSVKEY_force(entry));
2062 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2068 /* one HE per MAGICAL hash */
2069 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2071 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2073 HeKEY_hek(entry) = hek;
2074 HeKLEN(entry) = HEf_SVKEY;
2076 magic_nextpack(MUTABLE_SV(hv),mg,key);
2078 /* force key to stay around until next time */
2079 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2080 return entry; /* beware, hent_val is not set */
2083 SvREFCNT_dec(HeVAL(entry));
2084 Safefree(HeKEY_hek(entry));
2086 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2090 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2091 if (!entry && SvRMAGICAL((const SV *)hv)
2092 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2095 /* The prime_env_iter() on VMS just loaded up new hash values
2096 * so the iteration count needs to be reset back to the beginning
2100 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2105 /* hv_iterint now ensures this. */
2106 assert (HvARRAY(hv));
2108 /* At start of hash, entry is NULL. */
2111 entry = HeNEXT(entry);
2112 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2114 * Skip past any placeholders -- don't want to include them in
2117 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2118 entry = HeNEXT(entry);
2123 /* OK. Come to the end of the current list. Grab the next one. */
2125 iter->xhv_riter++; /* HvRITER(hv)++ */
2126 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2127 /* There is no next one. End of the hash. */
2128 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2131 entry = (HvARRAY(hv))[iter->xhv_riter];
2133 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2134 /* If we have an entry, but it's a placeholder, don't count it.
2136 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2137 entry = HeNEXT(entry);
2139 /* Will loop again if this linked list starts NULL
2140 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2141 or if we run through it and find only placeholders. */
2144 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2146 hv_free_ent(hv, oldentry);
2149 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2150 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2152 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2157 =for apidoc hv_iterkey
2159 Returns the key from the current position of the hash iterator. See
2166 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2168 PERL_ARGS_ASSERT_HV_ITERKEY;
2170 if (HeKLEN(entry) == HEf_SVKEY) {
2172 char * const p = SvPV(HeKEY_sv(entry), len);
2177 *retlen = HeKLEN(entry);
2178 return HeKEY(entry);
2182 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2184 =for apidoc hv_iterkeysv
2186 Returns the key as an C<SV*> from the current position of the hash
2187 iterator. The return value will always be a mortal copy of the key. Also
2194 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2196 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2198 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2202 =for apidoc hv_iterval
2204 Returns the value from the current position of the hash iterator. See
2211 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2213 PERL_ARGS_ASSERT_HV_ITERVAL;
2215 if (SvRMAGICAL(hv)) {
2216 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2217 SV* const sv = sv_newmortal();
2218 if (HeKLEN(entry) == HEf_SVKEY)
2219 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2221 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2225 return HeVAL(entry);
2229 =for apidoc hv_iternextsv
2231 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2238 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2240 HE * const he = hv_iternext_flags(hv, 0);
2242 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2246 *key = hv_iterkey(he, retlen);
2247 return hv_iterval(hv, he);
2254 =for apidoc hv_magic
2256 Adds magic to a hash. See C<sv_magic>.
2261 /* possibly free a shared string if no one has access to it
2262 * len and hash must both be valid for str.
2265 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2267 unshare_hek_or_pvn (NULL, str, len, hash);
2272 Perl_unshare_hek(pTHX_ HEK *hek)
2275 unshare_hek_or_pvn(hek, NULL, 0, 0);
2278 /* possibly free a shared string if no one has access to it
2279 hek if non-NULL takes priority over the other 3, else str, len and hash
2280 are used. If so, len and hash must both be valid for str.
2283 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2286 register XPVHV* xhv;
2288 register HE **oentry;
2290 bool is_utf8 = FALSE;
2292 const char * const save = str;
2293 struct shared_he *he = NULL;
2296 /* Find the shared he which is just before us in memory. */
2297 he = (struct shared_he *)(((char *)hek)
2298 - STRUCT_OFFSET(struct shared_he,
2301 /* Assert that the caller passed us a genuine (or at least consistent)
2303 assert (he->shared_he_he.hent_hek == hek);
2306 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2307 --he->shared_he_he.he_valu.hent_refcount;
2308 UNLOCK_STRTAB_MUTEX;
2311 UNLOCK_STRTAB_MUTEX;
2313 hash = HEK_HASH(hek);
2314 } else if (len < 0) {
2315 STRLEN tmplen = -len;
2317 /* See the note in hv_fetch(). --jhi */
2318 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2321 k_flags = HVhek_UTF8;
2323 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2326 /* what follows was the moral equivalent of:
2327 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2329 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2331 xhv = (XPVHV*)SvANY(PL_strtab);
2332 /* assert(xhv_array != 0) */
2334 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2336 const HE *const he_he = &(he->shared_he_he);
2337 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2342 const int flags_masked = k_flags & HVhek_MASK;
2343 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2344 if (HeHASH(entry) != hash) /* strings can't be equal */
2346 if (HeKLEN(entry) != len)
2348 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2350 if (HeKFLAGS(entry) != flags_masked)
2357 if (--entry->he_valu.hent_refcount == 0) {
2358 *oentry = HeNEXT(entry);
2360 /* There are now no entries in our slot. */
2361 xhv->xhv_fill--; /* HvFILL(hv)-- */
2364 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2368 UNLOCK_STRTAB_MUTEX;
2369 if (!entry && ckWARN_d(WARN_INTERNAL))
2370 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2371 "Attempt to free non-existent shared string '%s'%s"
2373 hek ? HEK_KEY(hek) : str,
2374 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2375 if (k_flags & HVhek_FREEKEY)
2379 /* get a (constant) string ptr from the global string table
2380 * string will get added if it is not already there.
2381 * len and hash must both be valid for str.
2384 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2386 bool is_utf8 = FALSE;
2388 const char * const save = str;
2390 PERL_ARGS_ASSERT_SHARE_HEK;
2393 STRLEN tmplen = -len;
2395 /* See the note in hv_fetch(). --jhi */
2396 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2398 /* If we were able to downgrade here, then than means that we were passed
2399 in a key which only had chars 0-255, but was utf8 encoded. */
2402 /* If we found we were able to downgrade the string to bytes, then
2403 we should flag that it needs upgrading on keys or each. Also flag
2404 that we need share_hek_flags to free the string. */
2406 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2409 return share_hek_flags (str, len, hash, flags);
2413 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2417 const int flags_masked = flags & HVhek_MASK;
2418 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2419 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2421 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2423 /* what follows is the moral equivalent of:
2425 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2426 hv_store(PL_strtab, str, len, NULL, hash);
2428 Can't rehash the shared string table, so not sure if it's worth
2429 counting the number of entries in the linked list
2432 /* assert(xhv_array != 0) */
2434 entry = (HvARRAY(PL_strtab))[hindex];
2435 for (;entry; entry = HeNEXT(entry)) {
2436 if (HeHASH(entry) != hash) /* strings can't be equal */
2438 if (HeKLEN(entry) != len)
2440 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2442 if (HeKFLAGS(entry) != flags_masked)
2448 /* What used to be head of the list.
2449 If this is NULL, then we're the first entry for this slot, which
2450 means we need to increate fill. */
2451 struct shared_he *new_entry;
2454 HE **const head = &HvARRAY(PL_strtab)[hindex];
2455 HE *const next = *head;
2457 /* We don't actually store a HE from the arena and a regular HEK.
2458 Instead we allocate one chunk of memory big enough for both,
2459 and put the HEK straight after the HE. This way we can find the
2460 HEK directly from the HE.
2463 Newx(k, STRUCT_OFFSET(struct shared_he,
2464 shared_he_hek.hek_key[0]) + len + 2, char);
2465 new_entry = (struct shared_he *)k;
2466 entry = &(new_entry->shared_he_he);
2467 hek = &(new_entry->shared_he_hek);
2469 Copy(str, HEK_KEY(hek), len, char);
2470 HEK_KEY(hek)[len] = 0;
2472 HEK_HASH(hek) = hash;
2473 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2475 /* Still "point" to the HEK, so that other code need not know what
2477 HeKEY_hek(entry) = hek;
2478 entry->he_valu.hent_refcount = 0;
2479 HeNEXT(entry) = next;
2482 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2483 if (!next) { /* initial entry? */
2484 xhv->xhv_fill++; /* HvFILL(hv)++ */
2485 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2490 ++entry->he_valu.hent_refcount;
2491 UNLOCK_STRTAB_MUTEX;
2493 if (flags & HVhek_FREEKEY)
2496 return HeKEY_hek(entry);
2500 Perl_hv_placeholders_p(pTHX_ HV *hv)
2503 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2505 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2508 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2511 Perl_die(aTHX_ "panic: hv_placeholders_p");
2514 return &(mg->mg_len);
2519 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2522 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2524 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2526 return mg ? mg->mg_len : 0;
2530 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2533 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2535 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2540 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2541 Perl_die(aTHX_ "panic: hv_placeholders_set");
2543 /* else we don't need to add magic to record 0 placeholders. */
2547 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2552 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2554 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2559 value = &PL_sv_placeholder;
2562 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2565 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2568 case HVrhek_PV_UTF8:
2569 /* Create a string SV that directly points to the bytes in our
2571 value = newSV_type(SVt_PV);
2572 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2573 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2574 /* This stops anything trying to free it */
2575 SvLEN_set(value, 0);
2577 SvREADONLY_on(value);
2578 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2582 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2583 he->refcounted_he_data[0]);
2589 =for apidoc refcounted_he_chain_2hv
2591 Generates and returns a C<HV *> by walking up the tree starting at the passed
2592 in C<struct refcounted_he *>.
2597 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2601 U32 placeholders = 0;
2602 /* We could chase the chain once to get an idea of the number of keys,
2603 and call ksplit. But for now we'll make a potentially inefficient
2604 hash with only 8 entries in its array. */
2605 const U32 max = HvMAX(hv);
2609 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2610 HvARRAY(hv) = (HE**)array;
2615 U32 hash = chain->refcounted_he_hash;
2617 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2619 HE **oentry = &((HvARRAY(hv))[hash & max]);
2620 HE *entry = *oentry;
2623 for (; entry; entry = HeNEXT(entry)) {
2624 if (HeHASH(entry) == hash) {
2625 /* We might have a duplicate key here. If so, entry is older
2626 than the key we've already put in the hash, so if they are
2627 the same, skip adding entry. */
2629 const STRLEN klen = HeKLEN(entry);
2630 const char *const key = HeKEY(entry);
2631 if (klen == chain->refcounted_he_keylen
2632 && (!!HeKUTF8(entry)
2633 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2634 && memEQ(key, REF_HE_KEY(chain), klen))
2637 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2639 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2640 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2641 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2652 = share_hek_flags(REF_HE_KEY(chain),
2653 chain->refcounted_he_keylen,
2654 chain->refcounted_he_hash,
2655 (chain->refcounted_he_data[0]
2656 & (HVhek_UTF8|HVhek_WASUTF8)));
2658 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2660 value = refcounted_he_value(chain);
2661 if (value == &PL_sv_placeholder)
2663 HeVAL(entry) = value;
2665 /* Link it into the chain. */
2666 HeNEXT(entry) = *oentry;
2667 if (!HeNEXT(entry)) {
2668 /* initial entry. */
2676 chain = chain->refcounted_he_next;
2680 clear_placeholders(hv, placeholders);
2681 HvTOTALKEYS(hv) -= placeholders;
2684 /* We could check in the loop to see if we encounter any keys with key
2685 flags, but it's probably not worth it, as this per-hash flag is only
2686 really meant as an optimisation for things like Storable. */
2688 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2694 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2695 const char *key, STRLEN klen, int flags, U32 hash)
2698 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2699 of your key has to exactly match that which is stored. */
2700 SV *value = &PL_sv_placeholder;
2703 /* No point in doing any of this if there's nothing to find. */
2707 if (flags & HVhek_FREEKEY)
2709 key = SvPV_const(keysv, klen);
2711 is_utf8 = (SvUTF8(keysv) != 0);
2713 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2717 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2718 hash = SvSHARED_HASH(keysv);
2720 PERL_HASH(hash, key, klen);
2724 for (; chain; chain = chain->refcounted_he_next) {
2726 if (hash != chain->refcounted_he_hash)
2728 if (klen != chain->refcounted_he_keylen)
2730 if (memNE(REF_HE_KEY(chain),key,klen))
2732 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2735 if (hash != HEK_HASH(chain->refcounted_he_hek))
2737 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2739 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2741 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2745 value = sv_2mortal(refcounted_he_value(chain));
2750 if (flags & HVhek_FREEKEY)
2757 =for apidoc refcounted_he_new
2759 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2760 stored in a compact form, all references remain the property of the caller.
2761 The C<struct refcounted_he> is returned with a reference count of 1.
2766 struct refcounted_he *
2767 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2768 SV *const key, SV *const value) {
2771 const char *key_p = SvPV_const(key, key_len);
2772 STRLEN value_len = 0;
2773 const char *value_p = NULL;
2776 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2779 value_type = HVrhek_PV;
2780 } else if (SvIOK(value)) {
2781 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2782 } else if (value == &PL_sv_placeholder) {
2783 value_type = HVrhek_delete;
2784 } else if (!SvOK(value)) {
2785 value_type = HVrhek_undef;
2787 value_type = HVrhek_PV;
2790 if (value_type == HVrhek_PV) {
2791 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2792 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2793 value_p = SvPV_const(value, value_len);
2795 value_type = HVrhek_PV_UTF8;
2800 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2801 As we're going to be building hash keys from this value in future,
2802 normalise it now. */
2803 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2804 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2807 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2808 ((value_type == HVrhek_PV
2809 || value_type == HVrhek_PV_UTF8) ?
2810 (void *)value_p : (void *)value),
2814 static struct refcounted_he *
2815 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2816 const char *const key_p, const STRLEN key_len,
2817 const char flags, char value_type,
2818 const void *value, const STRLEN value_len) {
2820 struct refcounted_he *he;
2822 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2823 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2825 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2828 he = (struct refcounted_he*)
2829 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2833 he = (struct refcounted_he*)
2834 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2838 he->refcounted_he_next = parent;
2841 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2842 he->refcounted_he_val.refcounted_he_u_len = value_len;
2843 } else if (value_type == HVrhek_IV) {
2844 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2845 } else if (value_type == HVrhek_UV) {
2846 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2849 PERL_HASH(hash, key_p, key_len);
2852 he->refcounted_he_hash = hash;
2853 he->refcounted_he_keylen = key_len;
2854 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2856 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2859 if (flags & HVhek_WASUTF8) {
2860 /* If it was downgraded from UTF-8, then the pointer returned from
2861 bytes_from_utf8 is an allocated pointer that we must free. */
2865 he->refcounted_he_data[0] = flags;
2866 he->refcounted_he_refcnt = 1;
2872 =for apidoc refcounted_he_free
2874 Decrements the reference count of the passed in C<struct refcounted_he *>
2875 by one. If the reference count reaches zero the structure's memory is freed,
2876 and C<refcounted_he_free> iterates onto the parent node.
2882 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2884 PERL_UNUSED_CONTEXT;
2887 struct refcounted_he *copy;
2891 new_count = --he->refcounted_he_refcnt;
2892 HINTS_REFCNT_UNLOCK;
2898 #ifndef USE_ITHREADS
2899 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2902 he = he->refcounted_he_next;
2903 PerlMemShared_free(copy);
2908 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2913 if (chain->refcounted_he_keylen != 1)
2915 if (*REF_HE_KEY(chain) != ':')
2918 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2920 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2923 /* Stop anyone trying to really mess us up by adding their own value for
2925 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2926 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2930 *len = chain->refcounted_he_val.refcounted_he_u_len;
2932 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2933 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
2935 return chain->refcounted_he_data + 1;
2938 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
2939 that interface. Once it works out how to pass in length and UTF-8 ness, this
2940 function will need superseding. */
2941 struct refcounted_he *
2942 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
2944 PERL_ARGS_ASSERT_STORE_COP_LABEL;
2946 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
2947 label, strlen(label));
2951 =for apidoc hv_assert
2953 Check that a hash is in an internally consistent state.
2961 Perl_hv_assert(pTHX_ HV *hv)
2966 int placeholders = 0;
2969 const I32 riter = HvRITER_get(hv);
2970 HE *eiter = HvEITER_get(hv);
2972 PERL_ARGS_ASSERT_HV_ASSERT;
2974 (void)hv_iterinit(hv);
2976 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2977 /* sanity check the values */
2978 if (HeVAL(entry) == &PL_sv_placeholder)
2982 /* sanity check the keys */
2983 if (HeSVKEY(entry)) {
2984 NOOP; /* Don't know what to check on SV keys. */
2985 } else if (HeKUTF8(entry)) {
2987 if (HeKWASUTF8(entry)) {
2988 PerlIO_printf(Perl_debug_log,
2989 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2990 (int) HeKLEN(entry), HeKEY(entry));
2993 } else if (HeKWASUTF8(entry))
2996 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
2997 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2998 const int nhashkeys = HvUSEDKEYS(hv);
2999 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3001 if (nhashkeys != real) {
3002 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3005 if (nhashplaceholders != placeholders) {
3006 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3010 if (withflags && ! HvHASKFLAGS(hv)) {
3011 PerlIO_printf(Perl_debug_log,
3012 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3017 sv_dump(MUTABLE_SV(hv));
3019 HvRITER_set(hv, riter); /* Restore hash iterator state */
3020 HvEITER_set(hv, eiter);
3027 * c-indentation-style: bsd
3029 * indent-tabs-mode: t
3032 * ex: set ts=8 sts=4 sw=4 noet: