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 DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
45 #define new_HE() (HE*)safemalloc(sizeof(HE))
46 #define del_HE(p) safefree((char*)p)
55 void ** const root = &PL_body_roots[HE_SVSLOT];
58 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
65 #define new_HE() new_he()
68 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
69 PL_body_roots[HE_SVSLOT] = p; \
77 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
79 const int flags_masked = flags & HVhek_MASK;
83 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
85 Newx(k, HEK_BASESIZE + len + 2, char);
87 Copy(str, HEK_KEY(hek), len, char);
88 HEK_KEY(hek)[len] = 0;
91 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
93 if (flags & HVhek_FREEKEY)
98 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
102 Perl_free_tied_hv_pool(pTHX)
105 HE *he = PL_hv_fetch_ent_mh;
108 Safefree(HeKEY_hek(he));
112 PL_hv_fetch_ent_mh = NULL;
115 #if defined(USE_ITHREADS)
117 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
121 PERL_ARGS_ASSERT_HEK_DUP;
122 PERL_UNUSED_ARG(param);
127 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
129 /* We already shared this hash key. */
130 (void)share_hek_hek(shared);
134 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
135 HEK_HASH(source), HEK_FLAGS(source));
136 ptr_table_store(PL_ptr_table, source, shared);
142 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
146 PERL_ARGS_ASSERT_HE_DUP;
150 /* look for it in the table first */
151 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
155 /* create anew and remember what it is */
157 ptr_table_store(PL_ptr_table, e, ret);
159 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
160 if (HeKLEN(e) == HEf_SVKEY) {
162 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
163 HeKEY_hek(ret) = (HEK*)k;
164 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
167 /* This is hek_dup inlined, which seems to be important for speed
169 HEK * const source = HeKEY_hek(e);
170 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
173 /* We already shared this hash key. */
174 (void)share_hek_hek(shared);
178 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
179 HEK_HASH(source), HEK_FLAGS(source));
180 ptr_table_store(PL_ptr_table, source, shared);
182 HeKEY_hek(ret) = shared;
185 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
187 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
190 #endif /* USE_ITHREADS */
193 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
196 SV * const sv = sv_newmortal();
198 PERL_ARGS_ASSERT_HV_NOTALLOWED;
200 if (!(flags & HVhek_FREEKEY)) {
201 sv_setpvn(sv, key, klen);
204 /* Need to free saved eventually assign to mortal SV */
205 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
206 sv_usepvn(sv, (char *) key, klen);
208 if (flags & HVhek_UTF8) {
211 Perl_croak(aTHX_ msg, SVfARG(sv));
214 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
220 Stores an SV in a hash. The hash key is specified as C<key> and the
221 absolute value of C<klen> is the length of the key. If C<klen> is
222 negative the key is assumed to be in UTF-8-encoded Unicode. The
223 C<hash> parameter is the precomputed hash value; if it is zero then
224 Perl will compute it.
226 The return value will be
227 NULL if the operation failed or if the value did not need to be actually
228 stored within the hash (as in the case of tied hashes). Otherwise it can
229 be dereferenced to get the original C<SV*>. Note that the caller is
230 responsible for suitably incrementing the reference count of C<val> before
231 the call, and decrementing it if the function returned NULL. Effectively
232 a successful hv_store takes ownership of one reference to C<val>. This is
233 usually what you want; a newly created SV has a reference count of one, so
234 if all your code does is create SVs then store them in a hash, hv_store
235 will own the only reference to the new SV, and your code doesn't need to do
236 anything further to tidy up. hv_store is not implemented as a call to
237 hv_store_ent, and does not create a temporary SV for the key, so if your
238 key data is not already in SV form then use hv_store in preference to
241 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
242 information on how to use this function on tied hashes.
244 =for apidoc hv_store_ent
246 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
247 parameter is the precomputed hash value; if it is zero then Perl will
248 compute it. The return value is the new hash entry so created. It will be
249 NULL if the operation failed or if the value did not need to be actually
250 stored within the hash (as in the case of tied hashes). Otherwise the
251 contents of the return value can be accessed using the C<He?> macros
252 described here. Note that the caller is responsible for suitably
253 incrementing the reference count of C<val> before the call, and
254 decrementing it if the function returned NULL. Effectively a successful
255 hv_store_ent takes ownership of one reference to C<val>. This is
256 usually what you want; a newly created SV has a reference count of one, so
257 if all your code does is create SVs then store them in a hash, hv_store
258 will own the only reference to the new SV, and your code doesn't need to do
259 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
260 unlike C<val> it does not take ownership of it, so maintaining the correct
261 reference count on C<key> is entirely the caller's responsibility. hv_store
262 is not implemented as a call to hv_store_ent, and does not create a temporary
263 SV for the key, so if your key data is not already in SV form then use
264 hv_store in preference to hv_store_ent.
266 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
267 information on how to use this function on tied hashes.
269 =for apidoc hv_exists
271 Returns a boolean indicating whether the specified hash key exists. The
272 absolute value of C<klen> is the length of the key. If C<klen> is
273 negative the key is assumed to be in UTF-8-encoded Unicode.
277 Returns the SV which corresponds to the specified key in the hash.
278 The absolute value of C<klen> is the length of the key. If C<klen> is
279 negative the key is assumed to be in UTF-8-encoded Unicode. If
280 C<lval> is set then the fetch will be part of a store. This means that if
281 there is no value in the hash associated with the given key, then one is
282 created and a pointer to it is returned. The C<SV*> it points to can be
283 assigned to. But always check that the
284 return value is non-null before dereferencing it to an C<SV*>.
286 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
287 information on how to use this function on tied hashes.
289 =for apidoc hv_exists_ent
291 Returns a boolean indicating whether
292 the specified hash key exists. C<hash>
293 can be a valid precomputed hash value, or 0 to ask for it to be
299 /* returns an HE * structure with the all fields set */
300 /* note that hent_val will be a mortal sv for MAGICAL hashes */
302 =for apidoc hv_fetch_ent
304 Returns the hash entry which corresponds to the specified key in the hash.
305 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
306 if you want the function to compute it. IF C<lval> is set then the fetch
307 will be part of a store. Make sure the return value is non-null before
308 accessing it. The return value when C<hv> is a tied hash is a pointer to a
309 static location, so be sure to make a copy of the structure if you need to
312 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
313 information on how to use this function on tied hashes.
318 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
320 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
321 const int action, SV *val, const U32 hash)
326 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
335 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
339 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
340 int flags, int action, SV *val, U32 hash)
349 const int return_svp = action & HV_FETCH_JUST_SV;
353 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
356 assert(SvTYPE(hv) == SVt_PVHV);
358 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
360 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
361 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
362 if (uf->uf_set == NULL) {
363 SV* obj = mg->mg_obj;
366 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
367 ((flags & HVhek_UTF8)
371 mg->mg_obj = keysv; /* pass key */
372 uf->uf_index = action; /* pass action */
373 magic_getuvar(MUTABLE_SV(hv), mg);
374 keysv = mg->mg_obj; /* may have changed */
377 /* If the key may have changed, then we need to invalidate
378 any passed-in computed hash value. */
384 if (flags & HVhek_FREEKEY)
386 key = SvPV_const(keysv, klen);
387 is_utf8 = (SvUTF8(keysv) != 0);
388 if (SvIsCOW_shared_hash(keysv)) {
389 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
391 flags = is_utf8 ? HVhek_UTF8 : 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, action, hash);
402 xhv = (XPVHV*)SvANY(hv);
404 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
405 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
406 || SvGMAGICAL((const SV *)hv))
408 /* FIXME should be able to skimp on the HE/HEK here when
409 HV_FETCH_JUST_SV is true. */
411 keysv = newSVpvn_utf8(key, klen, is_utf8);
413 keysv = newSVsv(keysv);
416 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
418 /* grab a fake HE/HEK pair from the pool or make a new one */
419 entry = PL_hv_fetch_ent_mh;
421 PL_hv_fetch_ent_mh = HeNEXT(entry);
425 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
426 HeKEY_hek(entry) = (HEK*)k;
428 HeNEXT(entry) = NULL;
429 HeSVKEY_set(entry, keysv);
431 sv_upgrade(sv, SVt_PVLV);
433 /* so we can free entry when freeing sv */
434 LvTARG(sv) = MUTABLE_SV(entry);
436 /* XXX remove at some point? */
437 if (flags & HVhek_FREEKEY)
441 return entry ? (void *) &HeVAL(entry) : NULL;
443 return (void *) entry;
445 #ifdef ENV_IS_CASELESS
446 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
448 for (i = 0; i < klen; ++i)
449 if (isLOWER(key[i])) {
450 /* Would be nice if we had a routine to do the
451 copy and upercase in a single pass through. */
452 const char * const nkey = strupr(savepvn(key,klen));
453 /* Note that this fetch is for nkey (the uppercased
454 key) whereas the store is for key (the original) */
455 void *result = hv_common(hv, NULL, nkey, klen,
456 HVhek_FREEKEY, /* free nkey */
457 0 /* non-LVAL fetch */
458 | HV_DISABLE_UVAR_XKEY
461 0 /* compute hash */);
462 if (!result && (action & HV_FETCH_LVALUE)) {
463 /* This call will free key if necessary.
464 Do it this way to encourage compiler to tail
466 result = hv_common(hv, keysv, key, klen, flags,
468 | HV_DISABLE_UVAR_XKEY
472 if (flags & HVhek_FREEKEY)
480 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
481 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
482 || SvGMAGICAL((const SV *)hv)) {
483 /* I don't understand why hv_exists_ent has svret and sv,
484 whereas hv_exists only had one. */
485 SV * const svret = sv_newmortal();
488 if (keysv || is_utf8) {
490 keysv = newSVpvn_utf8(key, klen, TRUE);
492 keysv = newSVsv(keysv);
494 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
496 mg_copy(MUTABLE_SV(hv), sv, key, klen);
498 if (flags & HVhek_FREEKEY)
500 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
501 /* This cast somewhat evil, but I'm merely using NULL/
502 not NULL to return the boolean exists.
503 And I know hv is not NULL. */
504 return SvTRUE(svret) ? (void *)hv : NULL;
506 #ifdef ENV_IS_CASELESS
507 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
508 /* XXX This code isn't UTF8 clean. */
509 char * const keysave = (char * const)key;
510 /* Will need to free this, so set FREEKEY flag. */
511 key = savepvn(key,klen);
512 key = (const char*)strupr((char*)key);
517 if (flags & HVhek_FREEKEY) {
520 flags |= HVhek_FREEKEY;
524 else if (action & HV_FETCH_ISSTORE) {
527 hv_magic_check (hv, &needs_copy, &needs_store);
529 const bool save_taint = TAINT_get;
530 if (keysv || is_utf8) {
532 keysv = newSVpvn_utf8(key, klen, TRUE);
535 TAINT_set(SvTAINTED(keysv));
536 keysv = sv_2mortal(newSVsv(keysv));
537 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
539 mg_copy(MUTABLE_SV(hv), val, key, klen);
542 TAINT_IF(save_taint);
543 #ifdef NO_TAINT_SUPPORT
544 PERL_UNUSED_VAR(save_taint);
547 if (flags & HVhek_FREEKEY)
551 #ifdef ENV_IS_CASELESS
552 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
553 /* XXX This code isn't UTF8 clean. */
554 const char *keysave = key;
555 /* Will need to free this, so set FREEKEY flag. */
556 key = savepvn(key,klen);
557 key = (const char*)strupr((char*)key);
562 if (flags & HVhek_FREEKEY) {
565 flags |= HVhek_FREEKEY;
573 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
574 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
575 || (SvRMAGICAL((const SV *)hv)
576 && mg_find((const SV *)hv, PERL_MAGIC_env))
581 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
583 HvARRAY(hv) = (HE**)array;
585 #ifdef DYNAMIC_ENV_FETCH
586 else if (action & HV_FETCH_ISEXISTS) {
587 /* for an %ENV exists, if we do an insert it's by a recursive
588 store call, so avoid creating HvARRAY(hv) right now. */
592 /* XXX remove at some point? */
593 if (flags & HVhek_FREEKEY)
600 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
601 char * const keysave = (char *)key;
602 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
606 flags &= ~HVhek_UTF8;
607 if (key != keysave) {
608 if (flags & HVhek_FREEKEY)
610 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
611 /* If the caller calculated a hash, it was on the sequence of
612 octets that are the UTF-8 form. We've now changed the sequence
613 of octets stored to that of the equivalent byte representation,
614 so the hash we need is different. */
620 if (keysv && (SvIsCOW_shared_hash(keysv)))
621 hash = SvSHARED_HASH(keysv);
623 PERL_HASH(hash, key, klen);
626 masked_flags = (flags & HVhek_MASK);
628 #ifdef DYNAMIC_ENV_FETCH
629 if (!HvARRAY(hv)) entry = NULL;
633 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
635 for (; entry; entry = HeNEXT(entry)) {
636 if (HeHASH(entry) != hash) /* strings can't be equal */
638 if (HeKLEN(entry) != (I32)klen)
640 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
642 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
645 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
646 if (HeKFLAGS(entry) != masked_flags) {
647 /* We match if HVhek_UTF8 bit in our flags and hash key's
648 match. But if entry was set previously with HVhek_WASUTF8
649 and key now doesn't (or vice versa) then we should change
650 the key's flag, as this is assignment. */
651 if (HvSHAREKEYS(hv)) {
652 /* Need to swap the key we have for a key with the flags we
653 need. As keys are shared we can't just write to the
654 flag, so we share the new one, unshare the old one. */
655 HEK * const new_hek = share_hek_flags(key, klen, hash,
657 unshare_hek (HeKEY_hek(entry));
658 HeKEY_hek(entry) = new_hek;
660 else if (hv == PL_strtab) {
661 /* PL_strtab is usually the only hash without HvSHAREKEYS,
662 so putting this test here is cheap */
663 if (flags & HVhek_FREEKEY)
665 Perl_croak(aTHX_ S_strtab_error,
666 action & HV_FETCH_LVALUE ? "fetch" : "store");
669 HeKFLAGS(entry) = masked_flags;
670 if (masked_flags & HVhek_ENABLEHVKFLAGS)
673 if (HeVAL(entry) == &PL_sv_placeholder) {
674 /* yes, can store into placeholder slot */
675 if (action & HV_FETCH_LVALUE) {
677 /* This preserves behaviour with the old hv_fetch
678 implementation which at this point would bail out
679 with a break; (at "if we find a placeholder, we
680 pretend we haven't found anything")
682 That break mean that if a placeholder were found, it
683 caused a call into hv_store, which in turn would
684 check magic, and if there is no magic end up pretty
685 much back at this point (in hv_store's code). */
688 /* LVAL fetch which actually needs a store. */
690 HvPLACEHOLDERS(hv)--;
693 if (val != &PL_sv_placeholder)
694 HvPLACEHOLDERS(hv)--;
697 } else if (action & HV_FETCH_ISSTORE) {
698 SvREFCNT_dec(HeVAL(entry));
701 } else if (HeVAL(entry) == &PL_sv_placeholder) {
702 /* if we find a placeholder, we pretend we haven't found
706 if (flags & HVhek_FREEKEY)
709 return entry ? (void *) &HeVAL(entry) : NULL;
713 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
714 if (!(action & HV_FETCH_ISSTORE)
715 && SvRMAGICAL((const SV *)hv)
716 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
718 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
720 sv = newSVpvn(env,len);
722 return hv_common(hv, keysv, key, klen, flags,
723 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
729 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
730 hv_notallowed(flags, key, klen,
731 "Attempt to access disallowed key '%"SVf"' in"
732 " a restricted hash");
734 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
735 /* Not doing some form of store, so return failure. */
736 if (flags & HVhek_FREEKEY)
740 if (action & HV_FETCH_LVALUE) {
741 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
743 /* At this point the old hv_fetch code would call to hv_store,
744 which in turn might do some tied magic. So we need to make that
745 magic check happen. */
746 /* gonna assign to this, so it better be there */
747 /* If a fetch-as-store fails on the fetch, then the action is to
748 recurse once into "hv_store". If we didn't do this, then that
749 recursive call would call the key conversion routine again.
750 However, as we replace the original key with the converted
751 key, this would result in a double conversion, which would show
752 up as a bug if the conversion routine is not idempotent. */
753 return hv_common(hv, keysv, key, klen, flags,
754 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
756 /* XXX Surely that could leak if the fetch-was-store fails?
757 Just like the hv_fetch. */
761 /* Welcome to hv_store... */
764 /* Not sure if we can get here. I think the only case of oentry being
765 NULL is for %ENV with dynamic env fetch. But that should disappear
766 with magic in the previous code. */
769 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
771 HvARRAY(hv) = (HE**)array;
774 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
777 /* share_hek_flags will do the free for us. This might be considered
780 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
781 else if (hv == PL_strtab) {
782 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
783 this test here is cheap */
784 if (flags & HVhek_FREEKEY)
786 Perl_croak(aTHX_ S_strtab_error,
787 action & HV_FETCH_LVALUE ? "fetch" : "store");
789 else /* gotta do the real thing */
790 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
793 #ifdef PERL_HASH_RANDOMIZE_KEYS
794 /* This logic semi-randomizes the insert order in a bucket.
795 * Either we insert into the top, or the slot below the top,
796 * making it harder to see if there is a collision. We also
797 * reset the iterator randomizer if there is one.
799 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
801 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
802 if ( PL_hash_rand_bits & 1 ) {
803 HeNEXT(entry) = HeNEXT(*oentry);
804 HeNEXT(*oentry) = entry;
806 HeNEXT(entry) = *oentry;
812 HeNEXT(entry) = *oentry;
815 #ifdef PERL_HASH_RANDOMIZE_KEYS
817 /* Currently this makes various tests warn in annoying ways.
818 * So Silenced for now. - Yves | bogus end of comment =>* /
819 if (HvAUX(hv)->xhv_riter != -1) {
820 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
821 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
826 if (PL_HASH_RAND_BITS_ENABLED) {
827 if (PL_HASH_RAND_BITS_ENABLED == 1)
828 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
829 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
831 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
835 if (val == &PL_sv_placeholder)
836 HvPLACEHOLDERS(hv)++;
837 if (masked_flags & HVhek_ENABLEHVKFLAGS)
840 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
841 if ( DO_HSPLIT(xhv) ) {
842 const STRLEN oldsize = xhv->xhv_max + 1;
843 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
845 if (items /* hash has placeholders */
846 && !SvREADONLY(hv) /* but is not a restricted hash */) {
847 /* If this hash previously was a "restricted hash" and had
848 placeholders, but the "restricted" flag has been turned off,
849 then the placeholders no longer serve any useful purpose.
850 However, they have the downsides of taking up RAM, and adding
851 extra steps when finding used values. It's safe to clear them
852 at this point, even though Storable rebuilds restricted hashes by
853 putting in all the placeholders (first) before turning on the
854 readonly flag, because Storable always pre-splits the hash.
855 If we're lucky, then we may clear sufficient placeholders to
856 avoid needing to split the hash at all. */
857 clear_placeholders(hv, items);
859 hsplit(hv, oldsize, oldsize * 2);
861 hsplit(hv, oldsize, oldsize * 2);
865 return entry ? (void *) &HeVAL(entry) : NULL;
867 return (void *) entry;
871 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
873 const MAGIC *mg = SvMAGIC(hv);
875 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
880 if (isUPPER(mg->mg_type)) {
882 if (mg->mg_type == PERL_MAGIC_tied) {
883 *needs_store = FALSE;
884 return; /* We've set all there is to set. */
887 mg = mg->mg_moremagic;
892 =for apidoc hv_scalar
894 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
900 Perl_hv_scalar(pTHX_ HV *hv)
904 PERL_ARGS_ASSERT_HV_SCALAR;
906 if (SvRMAGICAL(hv)) {
907 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
909 return magic_scalarpack(hv, mg);
913 if (HvTOTALKEYS((const HV *)hv))
914 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
915 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
923 =for apidoc hv_delete
925 Deletes a key/value pair in the hash. The value's SV is removed from
926 the hash, made mortal, and returned to the caller. The absolute
927 value of C<klen> is the length of the key. If C<klen> is negative the
928 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
929 will normally be zero; if set to G_DISCARD then NULL will be returned.
930 NULL will also be returned if the key is not found.
932 =for apidoc hv_delete_ent
934 Deletes a key/value pair in the hash. The value SV is removed from the hash,
935 made mortal, and returned to the caller. The C<flags> value will normally be
936 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
937 returned if the key is not found. C<hash> can be a valid precomputed hash
938 value, or 0 to ask for it to be computed.
944 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
945 int k_flags, I32 d_flags, U32 hash)
951 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
954 if (SvRMAGICAL(hv)) {
957 hv_magic_check (hv, &needs_copy, &needs_store);
961 entry = (HE *) hv_common(hv, keysv, key, klen,
962 k_flags & ~HVhek_FREEKEY,
963 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
965 sv = entry ? HeVAL(entry) : NULL;
971 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
972 /* No longer an element */
973 sv_unmagic(sv, PERL_MAGIC_tiedelem);
976 return NULL; /* element cannot be deleted */
978 #ifdef ENV_IS_CASELESS
979 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
980 /* XXX This code isn't UTF8 clean. */
981 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
982 if (k_flags & HVhek_FREEKEY) {
985 key = strupr(SvPVX(keysv));
994 xhv = (XPVHV*)SvANY(hv);
998 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
999 const char * const keysave = key;
1000 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1003 k_flags |= HVhek_UTF8;
1005 k_flags &= ~HVhek_UTF8;
1006 if (key != keysave) {
1007 if (k_flags & HVhek_FREEKEY) {
1008 /* This shouldn't happen if our caller does what we expect,
1009 but strictly the API allows it. */
1012 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1014 HvHASKFLAGS_on(MUTABLE_SV(hv));
1018 if (keysv && (SvIsCOW_shared_hash(keysv)))
1019 hash = SvSHARED_HASH(keysv);
1021 PERL_HASH(hash, key, klen);
1024 masked_flags = (k_flags & HVhek_MASK);
1026 oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1028 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1030 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1034 if (HeHASH(entry) != hash) /* strings can't be equal */
1036 if (HeKLEN(entry) != (I32)klen)
1038 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1040 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1043 if (hv == PL_strtab) {
1044 if (k_flags & HVhek_FREEKEY)
1046 Perl_croak(aTHX_ S_strtab_error, "delete");
1049 /* if placeholder is here, it's already been deleted.... */
1050 if (HeVAL(entry) == &PL_sv_placeholder) {
1051 if (k_flags & HVhek_FREEKEY)
1055 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))
1056 && !SvIsCOW(HeVAL(entry))) {
1057 hv_notallowed(k_flags, key, klen,
1058 "Attempt to delete readonly key '%"SVf"' from"
1059 " a restricted hash");
1061 if (k_flags & HVhek_FREEKEY)
1064 /* If this is a stash and the key ends with ::, then someone is
1065 * deleting a package.
1067 if (HeVAL(entry) && HvENAME_get(hv)) {
1068 gv = (GV *)HeVAL(entry);
1069 if (keysv) key = SvPV(keysv, klen);
1071 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1073 (klen == 1 && key[0] == ':')
1075 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1076 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1077 && HvENAME_get(stash)) {
1078 /* A previous version of this code checked that the
1079 * GV was still in the symbol table by fetching the
1080 * GV with its name. That is not necessary (and
1081 * sometimes incorrect), as HvENAME cannot be set
1082 * on hv if it is not in the symtab. */
1084 /* Hang on to it for a bit. */
1085 SvREFCNT_inc_simple_void_NN(
1086 sv_2mortal((SV *)gv)
1089 else if (klen == 3 && strnEQ(key, "ISA", 3))
1093 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1094 HeVAL(entry) = &PL_sv_placeholder;
1096 /* deletion of method from stash */
1097 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1099 mro_method_changed_in(hv);
1103 * If a restricted hash, rather than really deleting the entry, put
1104 * a placeholder there. This marks the key as being "approved", so
1105 * we can still access via not-really-existing key without raising
1109 /* We'll be saving this slot, so the number of allocated keys
1110 * doesn't go down, but the number placeholders goes up */
1111 HvPLACEHOLDERS(hv)++;
1113 *oentry = HeNEXT(entry);
1114 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1117 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1118 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1119 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1120 hv_free_ent(hv, entry);
1122 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1123 if (xhv->xhv_keys == 0)
1124 HvHASKFLAGS_off(hv);
1127 if (d_flags & G_DISCARD) {
1132 if (mro_changes == 1) mro_isa_changed_in(hv);
1133 else if (mro_changes == 2)
1134 mro_package_moved(NULL, stash, gv, 1);
1138 if (SvREADONLY(hv)) {
1139 hv_notallowed(k_flags, key, klen,
1140 "Attempt to delete disallowed key '%"SVf"' from"
1141 " a restricted hash");
1144 if (k_flags & HVhek_FREEKEY)
1150 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1154 char *a = (char*) HvARRAY(hv);
1157 PERL_ARGS_ASSERT_HSPLIT;
1159 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1160 (void*)hv, (int) oldsize);*/
1163 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1164 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1169 #ifdef PERL_HASH_RANDOMIZE_KEYS
1170 /* the idea of this is that we create a "random" value by hashing the address of
1171 * the array, we then use the low bit to decide if we insert at the top, or insert
1172 * second from top. After each such insert we rotate the hashed value. So we can
1173 * use the same hashed value over and over, and in normal build environments use
1174 * very few ops to do so. ROTL32() should produce a single machine operation. */
1175 if (PL_HASH_RAND_BITS_ENABLED) {
1176 if (PL_HASH_RAND_BITS_ENABLED == 1)
1177 PL_hash_rand_bits += ptr_hash((PTRV)a);
1178 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1183 struct xpvhv_aux *const dest
1184 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1185 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1186 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1187 #ifdef PERL_HASH_RANDOMIZE_KEYS
1188 dest->xhv_rand = (U32)PL_hash_rand_bits;
1193 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1194 HvMAX(hv) = --newsize;
1195 HvARRAY(hv) = (HE**) a;
1197 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1202 HE **oentry = aep + i;
1205 if (!entry) /* non-existent */
1208 U32 j = (HeHASH(entry) & newsize);
1210 *oentry = HeNEXT(entry);
1211 #ifdef PERL_HASH_RANDOMIZE_KEYS
1212 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1213 * insert to top, otherwise rotate the bucket rand 1 bit,
1214 * and use the new low bit to decide if we insert at top,
1215 * or next from top. IOW, we only rotate on a collision.*/
1216 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1217 PL_hash_rand_bits+= ROTL_UV(HeHASH(entry), 17);
1218 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1219 if (PL_hash_rand_bits & 1) {
1220 HeNEXT(entry)= HeNEXT(aep[j]);
1221 HeNEXT(aep[j])= entry;
1223 /* Note, this is structured in such a way as the optimizer
1224 * should eliminate the duplicated code here and below without
1225 * us needing to explicitly use a goto. */
1226 HeNEXT(entry) = aep[j];
1232 /* see comment above about duplicated code */
1233 HeNEXT(entry) = aep[j];
1238 oentry = &HeNEXT(entry);
1242 } while (i++ < oldsize);
1246 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1249 XPVHV* xhv = (XPVHV*)SvANY(hv);
1250 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
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);
1269 hsplit(hv, oldsize, newsize);
1271 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1272 xhv->xhv_max = --newsize;
1273 HvARRAY(hv) = (HE **) a;
1277 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1278 * as tied hashes could play silly buggers and mess us around. We will
1279 * do the right thing during hv_store() afterwards, but still - Yves */
1280 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1281 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1282 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1283 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1285 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1286 hv_max = hv_max / 2; \
1288 HvMAX(hv) = hv_max; \
1293 Perl_newHVhv(pTHX_ HV *ohv)
1296 HV * const hv = newHV();
1299 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1301 hv_max = HvMAX(ohv);
1303 if (!SvMAGICAL((const SV *)ohv)) {
1304 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1306 const bool shared = !!HvSHAREKEYS(ohv);
1307 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1309 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1312 /* In each bucket... */
1313 for (i = 0; i <= hv_max; i++) {
1315 HE *oent = oents[i];
1322 /* Copy the linked list of entries. */
1323 for (; oent; oent = HeNEXT(oent)) {
1324 const U32 hash = HeHASH(oent);
1325 const char * const key = HeKEY(oent);
1326 const STRLEN len = HeKLEN(oent);
1327 const int flags = HeKFLAGS(oent);
1328 HE * const ent = new_HE();
1329 SV *const val = HeVAL(oent);
1331 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1333 = shared ? share_hek_flags(key, len, hash, flags)
1334 : save_hek_flags(key, len, hash, flags);
1345 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1349 /* Iterate over ohv, copying keys and values one at a time. */
1351 const I32 riter = HvRITER_get(ohv);
1352 HE * const eiter = HvEITER_get(ohv);
1353 STRLEN hv_keys = HvTOTALKEYS(ohv);
1355 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1358 while ((entry = hv_iternext_flags(ohv, 0))) {
1359 SV *val = hv_iterval(ohv,entry);
1360 SV * const keysv = HeSVKEY(entry);
1361 val = SvIMMORTAL(val) ? val : newSVsv(val);
1363 (void)hv_store_ent(hv, keysv, val, 0);
1365 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1366 HeHASH(entry), HeKFLAGS(entry));
1368 HvRITER_set(ohv, riter);
1369 HvEITER_set(ohv, eiter);
1376 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1378 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1379 a pointer to a hash (which may have C<%^H> magic, but should be generally
1380 non-magical), or C<NULL> (interpreted as an empty hash). The content
1381 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1382 added to it. A pointer to the new hash is returned.
1388 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1390 HV * const hv = newHV();
1393 STRLEN hv_max = HvMAX(ohv);
1394 STRLEN hv_keys = HvTOTALKEYS(ohv);
1396 const I32 riter = HvRITER_get(ohv);
1397 HE * const eiter = HvEITER_get(ohv);
1402 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1405 while ((entry = hv_iternext_flags(ohv, 0))) {
1406 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1407 SV *heksv = HeSVKEY(entry);
1408 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1409 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1410 (char *)heksv, HEf_SVKEY);
1411 if (heksv == HeSVKEY(entry))
1412 (void)hv_store_ent(hv, heksv, sv, 0);
1414 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1415 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1416 SvREFCNT_dec_NN(heksv);
1419 HvRITER_set(ohv, riter);
1420 HvEITER_set(ohv, eiter);
1422 SvREFCNT_inc_simple_void_NN(hv);
1425 hv_magic(hv, NULL, PERL_MAGIC_hints);
1428 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1430 /* like hv_free_ent, but returns the SV rather than freeing it */
1432 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1437 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1440 if (HeKLEN(entry) == HEf_SVKEY) {
1441 SvREFCNT_dec(HeKEY_sv(entry));
1442 Safefree(HeKEY_hek(entry));
1444 else if (HvSHAREKEYS(hv))
1445 unshare_hek(HeKEY_hek(entry));
1447 Safefree(HeKEY_hek(entry));
1454 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1459 PERL_ARGS_ASSERT_HV_FREE_ENT;
1463 val = hv_free_ent_ret(hv, entry);
1469 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1473 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1477 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1478 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1479 if (HeKLEN(entry) == HEf_SVKEY) {
1480 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1482 hv_free_ent(hv, entry);
1486 =for apidoc hv_clear
1488 Frees the all the elements of a hash, leaving it empty.
1489 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1491 If any destructors are triggered as a result, the hv itself may
1498 Perl_hv_clear(pTHX_ HV *hv)
1505 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1507 xhv = (XPVHV*)SvANY(hv);
1510 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1511 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1512 /* restricted hash: convert all keys to placeholders */
1514 for (i = 0; i <= xhv->xhv_max; i++) {
1515 HE *entry = (HvARRAY(hv))[i];
1516 for (; entry; entry = HeNEXT(entry)) {
1517 /* not already placeholder */
1518 if (HeVAL(entry) != &PL_sv_placeholder) {
1520 if (SvREADONLY(HeVAL(entry)) && !SvIsCOW(HeVAL(entry))) {
1521 SV* const keysv = hv_iterkeysv(entry);
1522 Perl_croak_nocontext(
1523 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1526 SvREFCNT_dec_NN(HeVAL(entry));
1528 HeVAL(entry) = &PL_sv_placeholder;
1529 HvPLACEHOLDERS(hv)++;
1536 HvPLACEHOLDERS_set(hv, 0);
1539 mg_clear(MUTABLE_SV(hv));
1541 HvHASKFLAGS_off(hv);
1545 mro_isa_changed_in(hv);
1546 HvEITER_set(hv, NULL);
1552 =for apidoc hv_clear_placeholders
1554 Clears any placeholders from a hash. If a restricted hash has any of its keys
1555 marked as readonly and the key is subsequently deleted, the key is not actually
1556 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1557 it so it will be ignored by future operations such as iterating over the hash,
1558 but will still allow the hash to have a value reassigned to the key at some
1559 future point. This function clears any such placeholder keys from the hash.
1560 See Hash::Util::lock_keys() for an example of its use.
1566 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1569 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1571 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1574 clear_placeholders(hv, items);
1578 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1583 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1590 /* Loop down the linked list heads */
1591 HE **oentry = &(HvARRAY(hv))[i];
1594 while ((entry = *oentry)) {
1595 if (HeVAL(entry) == &PL_sv_placeholder) {
1596 *oentry = HeNEXT(entry);
1597 if (entry == HvEITER_get(hv))
1600 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1601 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1602 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1603 hv_free_ent(hv, entry);
1608 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1609 if (HvUSEDKEYS(hv) == 0)
1610 HvHASKFLAGS_off(hv);
1611 HvPLACEHOLDERS_set(hv, 0);
1615 oentry = &HeNEXT(entry);
1619 /* You can't get here, hence assertion should always fail. */
1620 assert (items == 0);
1625 S_hfreeentries(pTHX_ HV *hv)
1628 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1631 PERL_ARGS_ASSERT_HFREEENTRIES;
1633 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1639 /* hfree_next_entry()
1640 * For use only by S_hfreeentries() and sv_clear().
1641 * Delete the next available HE from hv and return the associated SV.
1642 * Returns null on empty hash. Nevertheless null is not a reliable
1643 * indicator that the hash is empty, as the deleted entry may have a
1645 * indexp is a pointer to the current index into HvARRAY. The index should
1646 * initially be set to 0. hfree_next_entry() may update it. */
1649 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1651 struct xpvhv_aux *iter;
1655 STRLEN orig_index = *indexp;
1658 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1660 if (SvOOK(hv) && ((iter = HvAUX(hv)))
1661 && ((entry = iter->xhv_eiter)) )
1663 /* the iterator may get resurrected after each
1664 * destructor call, so check each time */
1665 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1667 hv_free_ent(hv, entry);
1668 /* warning: at this point HvARRAY may have been
1669 * re-allocated, HvMAX changed etc */
1671 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1672 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1673 #ifdef PERL_HASH_RANDOMIZE_KEYS
1674 iter->xhv_last_rand = iter->xhv_rand;
1678 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1681 array = HvARRAY(hv);
1683 while ( ! ((entry = array[*indexp])) ) {
1684 if ((*indexp)++ >= HvMAX(hv))
1686 assert(*indexp != orig_index);
1688 array[*indexp] = HeNEXT(entry);
1689 ((XPVHV*) SvANY(hv))->xhv_keys--;
1691 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1692 && HeVAL(entry) && isGV(HeVAL(entry))
1693 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1696 const char * const key = HePV(entry,klen);
1697 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1698 || (klen == 1 && key[0] == ':')) {
1700 NULL, GvHV(HeVAL(entry)),
1701 (GV *)HeVAL(entry), 0
1705 return hv_free_ent_ret(hv, entry);
1710 =for apidoc hv_undef
1712 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1714 As well as freeing all the elements of the hash (like hv_clear()), this
1715 also frees any auxiliary data and storage associated with the hash.
1717 If any destructors are triggered as a result, the hv itself may
1720 See also L</hv_clear>.
1726 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1731 const bool save = !!SvREFCNT(hv);
1735 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1736 xhv = (XPVHV*)SvANY(hv);
1738 /* The name must be deleted before the call to hfreeeeentries so that
1739 CVs are anonymised properly. But the effective name must be pre-
1740 served until after that call (and only deleted afterwards if the
1741 call originated from sv_clear). For stashes with one name that is
1742 both the canonical name and the effective name, hv_name_set has to
1743 allocate an array for storing the effective name. We can skip that
1744 during global destruction, as it does not matter where the CVs point
1745 if they will be freed anyway. */
1746 /* note that the code following prior to hfreeentries is duplicated
1747 * in sv_clear(), and changes here should be done there too */
1748 if (PL_phase != PERL_PHASE_DESTRUCT && (name = HvNAME(hv))) {
1749 if (PL_stashcache) {
1750 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1751 HEKf"'\n", HvNAME_HEK(hv)));
1752 (void)hv_delete(PL_stashcache, name,
1753 HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv),
1757 hv_name_set(hv, NULL, 0, 0);
1761 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1765 struct xpvhv_aux * const aux = HvAUX(hv);
1766 struct mro_meta *meta;
1768 if ((name = HvENAME_get(hv))) {
1769 if (PL_phase != PERL_PHASE_DESTRUCT)
1770 mro_isa_changed_in(hv);
1771 if (PL_stashcache) {
1772 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1773 HEKf"'\n", HvENAME_HEK(hv)));
1775 PL_stashcache, name,
1776 HEK_UTF8(HvENAME_HEK(hv)) ? -HvENAMELEN_get(hv) : HvENAMELEN_get(hv),
1782 /* If this call originated from sv_clear, then we must check for
1783 * effective names that need freeing, as well as the usual name. */
1785 if (flags & HV_NAME_SETALL ? !!aux->xhv_name_u.xhvnameu_name : !!name) {
1786 if (name && PL_stashcache) {
1787 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1788 HEKf"'\n", HvNAME_HEK(hv)));
1789 (void)hv_delete(PL_stashcache, name, (HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv)), G_DISCARD);
1791 hv_name_set(hv, NULL, 0, flags);
1793 if((meta = aux->xhv_mro_meta)) {
1794 if (meta->mro_linear_all) {
1795 SvREFCNT_dec_NN(meta->mro_linear_all);
1796 /* mro_linear_current is just acting as a shortcut pointer,
1800 /* Only the current MRO is stored, so this owns the data.
1802 SvREFCNT_dec(meta->mro_linear_current);
1803 SvREFCNT_dec(meta->mro_nextmethod);
1804 SvREFCNT_dec(meta->isa);
1806 aux->xhv_mro_meta = NULL;
1808 SvREFCNT_dec(aux->xhv_super);
1809 if (!aux->xhv_name_u.xhvnameu_name && ! aux->xhv_backreferences)
1810 SvFLAGS(hv) &= ~SVf_OOK;
1813 Safefree(HvARRAY(hv));
1814 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1817 /* if we're freeing the HV, the SvMAGIC field has been reused for
1818 * other purposes, and so there can't be any placeholder magic */
1820 HvPLACEHOLDERS_set(hv, 0);
1823 mg_clear(MUTABLE_SV(hv));
1830 Returns the number of hash buckets that happen to be in use. This function is
1831 wrapped by the macro C<HvFILL>.
1833 Previously this value was stored in the HV structure, rather than being
1834 calculated on demand.
1840 Perl_hv_fill(pTHX_ HV const *const hv)
1843 HE **ents = HvARRAY(hv);
1845 PERL_ARGS_ASSERT_HV_FILL;
1848 HE *const *const last = ents + HvMAX(hv);
1849 count = last + 1 - ents;
1854 } while (++ents <= last);
1859 /* hash a pointer to a U32 - Used in the hash traversal randomization
1860 * and bucket order randomization code
1862 * this code was derived from Sereal, which was derived from autobox.
1865 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1868 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1869 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1871 u = (~u) + (u << 18);
1879 * This is one of Bob Jenkins' hash functions for 32-bit integers
1880 * from: http://burtleburtle.net/bob/hash/integer.html
1882 u = (u + 0x7ed55d16) + (u << 12);
1883 u = (u ^ 0xc761c23c) ^ (u >> 19);
1884 u = (u + 0x165667b1) + (u << 5);
1885 u = (u + 0xd3a2646c) ^ (u << 9);
1886 u = (u + 0xfd7046c5) + (u << 3);
1887 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1893 static struct xpvhv_aux*
1894 S_hv_auxinit(pTHX_ HV *hv) {
1895 struct xpvhv_aux *iter;
1898 PERL_ARGS_ASSERT_HV_AUXINIT;
1902 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1903 + sizeof(struct xpvhv_aux), char);
1905 array = (char *) HvARRAY(hv);
1906 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1907 + sizeof(struct xpvhv_aux), char);
1909 HvARRAY(hv) = (HE**)array;
1912 #ifdef PERL_HASH_RANDOMIZE_KEYS
1913 if (PL_HASH_RAND_BITS_ENABLED) {
1914 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
1915 if (PL_HASH_RAND_BITS_ENABLED == 1)
1916 PL_hash_rand_bits += ptr_hash((PTRV)array);
1917 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1919 iter->xhv_rand = (U32)PL_hash_rand_bits;
1925 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1926 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1927 #ifdef PERL_HASH_RANDOMIZE_KEYS
1928 iter->xhv_last_rand = iter->xhv_rand;
1930 iter->xhv_name_u.xhvnameu_name = 0;
1931 iter->xhv_name_count = 0;
1932 iter->xhv_backreferences = 0;
1933 iter->xhv_mro_meta = NULL;
1934 iter->xhv_super = NULL;
1939 =for apidoc hv_iterinit
1941 Prepares a starting point to traverse a hash table. Returns the number of
1942 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
1943 currently only meaningful for hashes without tie magic.
1945 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1946 hash buckets that happen to be in use. If you still need that esoteric
1947 value, you can get it through the macro C<HvFILL(hv)>.
1954 Perl_hv_iterinit(pTHX_ HV *hv)
1956 PERL_ARGS_ASSERT_HV_ITERINIT;
1958 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1961 Perl_croak(aTHX_ "Bad hash");
1964 struct xpvhv_aux * const iter = HvAUX(hv);
1965 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1966 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1968 hv_free_ent(hv, entry);
1970 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1971 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1972 #ifdef PERL_HASH_RANDOMIZE_KEYS
1973 iter->xhv_last_rand = iter->xhv_rand;
1979 /* used to be xhv->xhv_fill before 5.004_65 */
1980 return HvTOTALKEYS(hv);
1984 Perl_hv_riter_p(pTHX_ HV *hv) {
1985 struct xpvhv_aux *iter;
1987 PERL_ARGS_ASSERT_HV_RITER_P;
1990 Perl_croak(aTHX_ "Bad hash");
1992 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1993 return &(iter->xhv_riter);
1997 Perl_hv_eiter_p(pTHX_ HV *hv) {
1998 struct xpvhv_aux *iter;
2000 PERL_ARGS_ASSERT_HV_EITER_P;
2003 Perl_croak(aTHX_ "Bad hash");
2005 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2006 return &(iter->xhv_eiter);
2010 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2011 struct xpvhv_aux *iter;
2013 PERL_ARGS_ASSERT_HV_RITER_SET;
2016 Perl_croak(aTHX_ "Bad hash");
2024 iter = hv_auxinit(hv);
2026 iter->xhv_riter = riter;
2030 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2031 struct xpvhv_aux *iter;
2033 PERL_ARGS_ASSERT_HV_RAND_SET;
2035 #ifdef PERL_HASH_RANDOMIZE_KEYS
2037 Perl_croak(aTHX_ "Bad hash");
2042 iter = hv_auxinit(hv);
2044 iter->xhv_rand = new_xhv_rand;
2046 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2051 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2052 struct xpvhv_aux *iter;
2054 PERL_ARGS_ASSERT_HV_EITER_SET;
2057 Perl_croak(aTHX_ "Bad hash");
2062 /* 0 is the default so don't go malloc()ing a new structure just to
2067 iter = hv_auxinit(hv);
2069 iter->xhv_eiter = eiter;
2073 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2076 struct xpvhv_aux *iter;
2080 PERL_ARGS_ASSERT_HV_NAME_SET;
2083 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2087 if (iter->xhv_name_u.xhvnameu_name) {
2088 if(iter->xhv_name_count) {
2089 if(flags & HV_NAME_SETALL) {
2090 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2091 HEK **hekp = name + (
2092 iter->xhv_name_count < 0
2093 ? -iter->xhv_name_count
2094 : iter->xhv_name_count
2096 while(hekp-- > name+1)
2097 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2098 /* The first elem may be null. */
2099 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2101 spot = &iter->xhv_name_u.xhvnameu_name;
2102 iter->xhv_name_count = 0;
2105 if(iter->xhv_name_count > 0) {
2106 /* shift some things over */
2108 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2110 spot = iter->xhv_name_u.xhvnameu_names;
2111 spot[iter->xhv_name_count] = spot[1];
2113 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2115 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2116 unshare_hek_or_pvn(*spot, 0, 0, 0);
2120 else if (flags & HV_NAME_SETALL) {
2121 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2122 spot = &iter->xhv_name_u.xhvnameu_name;
2125 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2126 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2127 iter->xhv_name_count = -2;
2128 spot = iter->xhv_name_u.xhvnameu_names;
2129 spot[1] = existing_name;
2132 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2137 iter = hv_auxinit(hv);
2138 spot = &iter->xhv_name_u.xhvnameu_name;
2140 PERL_HASH(hash, name, len);
2141 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2145 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2150 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2151 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2152 if (flags & SVf_UTF8)
2153 return (bytes_cmp_utf8(
2154 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2155 (const U8*)pv, pvlen) == 0);
2157 return (bytes_cmp_utf8(
2158 (const U8*)pv, pvlen,
2159 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2162 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2163 || memEQ(HEK_KEY(hek), pv, pvlen));
2167 =for apidoc hv_ename_add
2169 Adds a name to a stash's internal list of effective names. See
2172 This is called when a stash is assigned to a new location in the symbol
2179 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2182 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2185 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2188 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2190 PERL_HASH(hash, name, len);
2192 if (aux->xhv_name_count) {
2193 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2194 I32 count = aux->xhv_name_count;
2195 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2196 while (hekp-- > xhv_name)
2198 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2199 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2200 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2202 if (hekp == xhv_name && count < 0)
2203 aux->xhv_name_count = -count;
2206 if (count < 0) aux->xhv_name_count--, count = -count;
2207 else aux->xhv_name_count++;
2208 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2209 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2212 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2215 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2216 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2217 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2220 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2221 aux->xhv_name_count = existing_name ? 2 : -2;
2222 *aux->xhv_name_u.xhvnameu_names = existing_name;
2223 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2228 =for apidoc hv_ename_delete
2230 Removes a name from a stash's internal list of effective names. If this is
2231 the name returned by C<HvENAME>, then another name in the list will take
2232 its place (C<HvENAME> will use it).
2234 This is called when a stash is deleted from the symbol table.
2240 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2243 struct xpvhv_aux *aux;
2245 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2248 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2250 if (!SvOOK(hv)) return;
2253 if (!aux->xhv_name_u.xhvnameu_name) return;
2255 if (aux->xhv_name_count) {
2256 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2257 I32 const count = aux->xhv_name_count;
2258 HEK **victim = namep + (count < 0 ? -count : count);
2259 while (victim-- > namep + 1)
2261 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2262 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2263 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2265 unshare_hek_or_pvn(*victim, 0, 0, 0);
2266 if (count < 0) ++aux->xhv_name_count;
2267 else --aux->xhv_name_count;
2269 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2271 ) { /* if there are none left */
2273 aux->xhv_name_u.xhvnameu_names = NULL;
2274 aux->xhv_name_count = 0;
2277 /* Move the last one back to fill the empty slot. It
2278 does not matter what order they are in. */
2279 *victim = *(namep + (count < 0 ? -count : count) - 1);
2284 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2285 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2286 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2288 aux->xhv_name_count = -count;
2292 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2293 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2294 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2295 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2297 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2298 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2299 *aux->xhv_name_u.xhvnameu_names = namehek;
2300 aux->xhv_name_count = -1;
2305 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2306 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2308 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2309 PERL_UNUSED_CONTEXT;
2311 return &(iter->xhv_backreferences);
2315 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2318 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2323 av = HvAUX(hv)->xhv_backreferences;
2326 HvAUX(hv)->xhv_backreferences = 0;
2327 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2328 if (SvTYPE(av) == SVt_PVAV)
2329 SvREFCNT_dec_NN(av);
2334 hv_iternext is implemented as a macro in hv.h
2336 =for apidoc hv_iternext
2338 Returns entries from a hash iterator. See C<hv_iterinit>.
2340 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2341 iterator currently points to, without losing your place or invalidating your
2342 iterator. Note that in this case the current entry is deleted from the hash
2343 with your iterator holding the last reference to it. Your iterator is flagged
2344 to free the entry on the next call to C<hv_iternext>, so you must not discard
2345 your iterator immediately else the entry will leak - call C<hv_iternext> to
2346 trigger the resource deallocation.
2348 =for apidoc hv_iternext_flags
2350 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2351 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2352 set the placeholders keys (for restricted hashes) will be returned in addition
2353 to normal keys. By default placeholders are automatically skipped over.
2354 Currently a placeholder is implemented with a value that is
2355 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2356 restricted hashes may change, and the implementation currently is
2357 insufficiently abstracted for any change to be tidy.
2363 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2370 struct xpvhv_aux *iter;
2372 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2375 Perl_croak(aTHX_ "Bad hash");
2377 xhv = (XPVHV*)SvANY(hv);
2380 /* Too many things (well, pp_each at least) merrily assume that you can
2381 call hv_iternext without calling hv_iterinit, so we'll have to deal
2387 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2388 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2389 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2390 SV * const key = sv_newmortal();
2392 sv_setsv(key, HeSVKEY_force(entry));
2393 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2394 HeSVKEY_set(entry, NULL);
2400 /* one HE per MAGICAL hash */
2401 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2402 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2404 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2406 HeKEY_hek(entry) = hek;
2407 HeKLEN(entry) = HEf_SVKEY;
2409 magic_nextpack(MUTABLE_SV(hv),mg,key);
2411 /* force key to stay around until next time */
2412 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2413 return entry; /* beware, hent_val is not set */
2415 SvREFCNT_dec(HeVAL(entry));
2416 Safefree(HeKEY_hek(entry));
2418 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2423 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2424 if (!entry && SvRMAGICAL((const SV *)hv)
2425 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2428 /* The prime_env_iter() on VMS just loaded up new hash values
2429 * so the iteration count needs to be reset back to the beginning
2433 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2438 /* hv_iterinit now ensures this. */
2439 assert (HvARRAY(hv));
2441 /* At start of hash, entry is NULL. */
2444 entry = HeNEXT(entry);
2445 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2447 * Skip past any placeholders -- don't want to include them in
2450 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2451 entry = HeNEXT(entry);
2456 #ifdef PERL_HASH_RANDOMIZE_KEYS
2457 if (iter->xhv_last_rand != iter->xhv_rand) {
2458 if (iter->xhv_riter != -1) {
2459 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2460 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2464 iter->xhv_last_rand = iter->xhv_rand;
2468 /* Skip the entire loop if the hash is empty. */
2469 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2470 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2472 /* OK. Come to the end of the current list. Grab the next one. */
2474 iter->xhv_riter++; /* HvRITER(hv)++ */
2475 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2476 /* There is no next one. End of the hash. */
2477 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2478 #ifdef PERL_HASH_RANDOMIZE_KEYS
2479 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2483 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2485 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2486 /* If we have an entry, but it's a placeholder, don't count it.
2488 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2489 entry = HeNEXT(entry);
2491 /* Will loop again if this linked list starts NULL
2492 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2493 or if we run through it and find only placeholders. */
2497 iter->xhv_riter = -1;
2498 #ifdef PERL_HASH_RANDOMIZE_KEYS
2499 iter->xhv_last_rand = iter->xhv_rand;
2503 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2505 hv_free_ent(hv, oldentry);
2508 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2513 =for apidoc hv_iterkey
2515 Returns the key from the current position of the hash iterator. See
2522 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2524 PERL_ARGS_ASSERT_HV_ITERKEY;
2526 if (HeKLEN(entry) == HEf_SVKEY) {
2528 char * const p = SvPV(HeKEY_sv(entry), len);
2533 *retlen = HeKLEN(entry);
2534 return HeKEY(entry);
2538 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2540 =for apidoc hv_iterkeysv
2542 Returns the key as an C<SV*> from the current position of the hash
2543 iterator. The return value will always be a mortal copy of the key. Also
2550 Perl_hv_iterkeysv(pTHX_ HE *entry)
2552 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2554 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2558 =for apidoc hv_iterval
2560 Returns the value from the current position of the hash iterator. See
2567 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2569 PERL_ARGS_ASSERT_HV_ITERVAL;
2571 if (SvRMAGICAL(hv)) {
2572 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2573 SV* const sv = sv_newmortal();
2574 if (HeKLEN(entry) == HEf_SVKEY)
2575 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2577 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2581 return HeVAL(entry);
2585 =for apidoc hv_iternextsv
2587 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2594 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2596 HE * const he = hv_iternext_flags(hv, 0);
2598 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2602 *key = hv_iterkey(he, retlen);
2603 return hv_iterval(hv, he);
2610 =for apidoc hv_magic
2612 Adds magic to a hash. See C<sv_magic>.
2617 /* possibly free a shared string if no one has access to it
2618 * len and hash must both be valid for str.
2621 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2623 unshare_hek_or_pvn (NULL, str, len, hash);
2628 Perl_unshare_hek(pTHX_ HEK *hek)
2631 unshare_hek_or_pvn(hek, NULL, 0, 0);
2634 /* possibly free a shared string if no one has access to it
2635 hek if non-NULL takes priority over the other 3, else str, len and hash
2636 are used. If so, len and hash must both be valid for str.
2639 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2645 bool is_utf8 = FALSE;
2647 const char * const save = str;
2648 struct shared_he *he = NULL;
2651 /* Find the shared he which is just before us in memory. */
2652 he = (struct shared_he *)(((char *)hek)
2653 - STRUCT_OFFSET(struct shared_he,
2656 /* Assert that the caller passed us a genuine (or at least consistent)
2658 assert (he->shared_he_he.hent_hek == hek);
2660 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2661 --he->shared_he_he.he_valu.hent_refcount;
2665 hash = HEK_HASH(hek);
2666 } else if (len < 0) {
2667 STRLEN tmplen = -len;
2669 /* See the note in hv_fetch(). --jhi */
2670 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2673 k_flags = HVhek_UTF8;
2675 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2678 /* what follows was the moral equivalent of:
2679 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2681 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2683 xhv = (XPVHV*)SvANY(PL_strtab);
2684 /* assert(xhv_array != 0) */
2685 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2687 const HE *const he_he = &(he->shared_he_he);
2688 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2693 const int flags_masked = k_flags & HVhek_MASK;
2694 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2695 if (HeHASH(entry) != hash) /* strings can't be equal */
2697 if (HeKLEN(entry) != len)
2699 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2701 if (HeKFLAGS(entry) != flags_masked)
2708 if (--entry->he_valu.hent_refcount == 0) {
2709 *oentry = HeNEXT(entry);
2711 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2716 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2717 "Attempt to free nonexistent shared string '%s'%s"
2719 hek ? HEK_KEY(hek) : str,
2720 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2721 if (k_flags & HVhek_FREEKEY)
2725 /* get a (constant) string ptr from the global string table
2726 * string will get added if it is not already there.
2727 * len and hash must both be valid for str.
2730 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2732 bool is_utf8 = FALSE;
2734 const char * const save = str;
2736 PERL_ARGS_ASSERT_SHARE_HEK;
2739 STRLEN tmplen = -len;
2741 /* See the note in hv_fetch(). --jhi */
2742 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2744 /* If we were able to downgrade here, then than means that we were passed
2745 in a key which only had chars 0-255, but was utf8 encoded. */
2748 /* If we found we were able to downgrade the string to bytes, then
2749 we should flag that it needs upgrading on keys or each. Also flag
2750 that we need share_hek_flags to free the string. */
2753 PERL_HASH(hash, str, len);
2754 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2758 return share_hek_flags (str, len, hash, flags);
2762 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2766 const int flags_masked = flags & HVhek_MASK;
2767 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2768 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2770 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2772 /* what follows is the moral equivalent of:
2774 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2775 hv_store(PL_strtab, str, len, NULL, hash);
2777 Can't rehash the shared string table, so not sure if it's worth
2778 counting the number of entries in the linked list
2781 /* assert(xhv_array != 0) */
2782 entry = (HvARRAY(PL_strtab))[hindex];
2783 for (;entry; entry = HeNEXT(entry)) {
2784 if (HeHASH(entry) != hash) /* strings can't be equal */
2786 if (HeKLEN(entry) != len)
2788 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2790 if (HeKFLAGS(entry) != flags_masked)
2796 /* What used to be head of the list.
2797 If this is NULL, then we're the first entry for this slot, which
2798 means we need to increate fill. */
2799 struct shared_he *new_entry;
2802 HE **const head = &HvARRAY(PL_strtab)[hindex];
2803 HE *const next = *head;
2805 /* We don't actually store a HE from the arena and a regular HEK.
2806 Instead we allocate one chunk of memory big enough for both,
2807 and put the HEK straight after the HE. This way we can find the
2808 HE directly from the HEK.
2811 Newx(k, STRUCT_OFFSET(struct shared_he,
2812 shared_he_hek.hek_key[0]) + len + 2, char);
2813 new_entry = (struct shared_he *)k;
2814 entry = &(new_entry->shared_he_he);
2815 hek = &(new_entry->shared_he_hek);
2817 Copy(str, HEK_KEY(hek), len, char);
2818 HEK_KEY(hek)[len] = 0;
2820 HEK_HASH(hek) = hash;
2821 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2823 /* Still "point" to the HEK, so that other code need not know what
2825 HeKEY_hek(entry) = hek;
2826 entry->he_valu.hent_refcount = 0;
2827 HeNEXT(entry) = next;
2830 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2831 if (!next) { /* initial entry? */
2832 } else if ( DO_HSPLIT(xhv) ) {
2833 const STRLEN oldsize = xhv->xhv_max + 1;
2834 hsplit(PL_strtab, oldsize, oldsize * 2);
2838 ++entry->he_valu.hent_refcount;
2840 if (flags & HVhek_FREEKEY)
2843 return HeKEY_hek(entry);
2847 Perl_hv_placeholders_p(pTHX_ HV *hv)
2850 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2852 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2855 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2858 Perl_die(aTHX_ "panic: hv_placeholders_p");
2861 return &(mg->mg_len);
2866 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2869 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2871 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2873 return mg ? mg->mg_len : 0;
2877 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2880 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2882 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2887 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2888 Perl_die(aTHX_ "panic: hv_placeholders_set");
2890 /* else we don't need to add magic to record 0 placeholders. */
2894 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2899 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2901 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2906 value = &PL_sv_placeholder;
2909 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2912 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2915 case HVrhek_PV_UTF8:
2916 /* Create a string SV that directly points to the bytes in our
2918 value = newSV_type(SVt_PV);
2919 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2920 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2921 /* This stops anything trying to free it */
2922 SvLEN_set(value, 0);
2924 SvREADONLY_on(value);
2925 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2929 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2930 (UV)he->refcounted_he_data[0]);
2936 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2938 Generates and returns a C<HV *> representing the content of a
2939 C<refcounted_he> chain.
2940 I<flags> is currently unused and must be zero.
2945 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2949 U32 placeholders, max;
2952 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
2955 /* We could chase the chain once to get an idea of the number of keys,
2956 and call ksplit. But for now we'll make a potentially inefficient
2957 hash with only 8 entries in its array. */
2962 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2963 HvARRAY(hv) = (HE**)array;
2969 U32 hash = chain->refcounted_he_hash;
2971 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2973 HE **oentry = &((HvARRAY(hv))[hash & max]);
2974 HE *entry = *oentry;
2977 for (; entry; entry = HeNEXT(entry)) {
2978 if (HeHASH(entry) == hash) {
2979 /* We might have a duplicate key here. If so, entry is older
2980 than the key we've already put in the hash, so if they are
2981 the same, skip adding entry. */
2983 const STRLEN klen = HeKLEN(entry);
2984 const char *const key = HeKEY(entry);
2985 if (klen == chain->refcounted_he_keylen
2986 && (!!HeKUTF8(entry)
2987 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2988 && memEQ(key, REF_HE_KEY(chain), klen))
2991 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2993 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2994 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2995 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3006 = share_hek_flags(REF_HE_KEY(chain),
3007 chain->refcounted_he_keylen,
3008 chain->refcounted_he_hash,
3009 (chain->refcounted_he_data[0]
3010 & (HVhek_UTF8|HVhek_WASUTF8)));
3012 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3014 value = refcounted_he_value(chain);
3015 if (value == &PL_sv_placeholder)
3017 HeVAL(entry) = value;
3019 /* Link it into the chain. */
3020 HeNEXT(entry) = *oentry;
3026 chain = chain->refcounted_he_next;
3030 clear_placeholders(hv, placeholders);
3031 HvTOTALKEYS(hv) -= placeholders;
3034 /* We could check in the loop to see if we encounter any keys with key
3035 flags, but it's probably not worth it, as this per-hash flag is only
3036 really meant as an optimisation for things like Storable. */
3038 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3044 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3046 Search along a C<refcounted_he> chain for an entry with the key specified
3047 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3048 bit set, the key octets are interpreted as UTF-8, otherwise they
3049 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3050 string, or zero if it has not been precomputed. Returns a mortal scalar
3051 representing the value associated with the key, or C<&PL_sv_placeholder>
3052 if there is no value associated with the key.
3058 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3059 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3063 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3065 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3066 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3069 return &PL_sv_placeholder;
3070 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3071 /* For searching purposes, canonicalise to Latin-1 where possible. */
3072 const char *keyend = keypv + keylen, *p;
3073 STRLEN nonascii_count = 0;
3074 for (p = keypv; p != keyend; p++) {
3077 if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
3078 (((U8)*p) & 0xc0) == 0x80))
3079 goto canonicalised_key;
3083 if (nonascii_count) {
3085 const char *p = keypv, *keyend = keypv + keylen;
3086 keylen -= nonascii_count;
3087 Newx(q, keylen, char);
3090 for (; p != keyend; p++, q++) {
3093 ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
3096 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3097 canonicalised_key: ;
3099 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3101 PERL_HASH(hash, keypv, keylen);
3103 for (; chain; chain = chain->refcounted_he_next) {
3106 hash == chain->refcounted_he_hash &&
3107 keylen == chain->refcounted_he_keylen &&
3108 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3109 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3111 hash == HEK_HASH(chain->refcounted_he_hek) &&
3112 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3113 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3114 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3117 if (flags & REFCOUNTED_HE_EXISTS)
3118 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3120 ? NULL : &PL_sv_yes;
3121 return sv_2mortal(refcounted_he_value(chain));
3124 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3128 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3130 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3131 instead of a string/length pair.
3137 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3138 const char *key, U32 hash, U32 flags)
3140 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3141 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3145 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3147 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3154 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3155 SV *key, U32 hash, U32 flags)
3159 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3160 if (flags & REFCOUNTED_HE_KEY_UTF8)
3161 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3163 keypv = SvPV_const(key, keylen);
3165 flags |= REFCOUNTED_HE_KEY_UTF8;
3166 if (!hash && SvIsCOW_shared_hash(key))
3167 hash = SvSHARED_HASH(key);
3168 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3172 =for apidoc m|struct refcounted_he *|refcounted_he_new_pvn|struct refcounted_he *parent|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
3174 Creates a new C<refcounted_he>. This consists of a single key/value
3175 pair and a reference to an existing C<refcounted_he> chain (which may
3176 be empty), and thus forms a longer chain. When using the longer chain,
3177 the new key/value pair takes precedence over any entry for the same key
3178 further along the chain.
3180 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3181 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3182 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3183 a precomputed hash of the key string, or zero if it has not been
3186 I<value> is the scalar value to store for this key. I<value> is copied
3187 by this function, which thus does not take ownership of any reference
3188 to it, and later changes to the scalar will not be reflected in the
3189 value visible in the C<refcounted_he>. Complex types of scalar will not
3190 be stored with referential integrity, but will be coerced to strings.
3191 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3192 value is to be associated with the key; this, as with any non-null value,
3193 takes precedence over the existence of a value for the key further along
3196 I<parent> points to the rest of the C<refcounted_he> chain to be
3197 attached to the new C<refcounted_he>. This function takes ownership
3198 of one reference to I<parent>, and returns one reference to the new
3204 struct refcounted_he *
3205 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3206 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3209 STRLEN value_len = 0;
3210 const char *value_p = NULL;
3214 STRLEN key_offset = 1;
3215 struct refcounted_he *he;
3216 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3218 if (!value || value == &PL_sv_placeholder) {
3219 value_type = HVrhek_delete;
3220 } else if (SvPOK(value)) {
3221 value_type = HVrhek_PV;
3222 } else if (SvIOK(value)) {
3223 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3224 } else if (!SvOK(value)) {
3225 value_type = HVrhek_undef;
3227 value_type = HVrhek_PV;
3229 is_pv = value_type == HVrhek_PV;
3231 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3232 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3233 value_p = SvPV_const(value, value_len);
3235 value_type = HVrhek_PV_UTF8;
3236 key_offset = value_len + 2;
3238 hekflags = value_type;
3240 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3241 /* Canonicalise to Latin-1 where possible. */
3242 const char *keyend = keypv + keylen, *p;
3243 STRLEN nonascii_count = 0;
3244 for (p = keypv; p != keyend; p++) {
3247 if (!((c & 0xfe) == 0xc2 && ++p != keyend &&
3248 (((U8)*p) & 0xc0) == 0x80))
3249 goto canonicalised_key;
3253 if (nonascii_count) {
3255 const char *p = keypv, *keyend = keypv + keylen;
3256 keylen -= nonascii_count;
3257 Newx(q, keylen, char);
3260 for (; p != keyend; p++, q++) {
3263 ((c & 0x80) ? ((c & 0x03) << 6) | (((U8)*++p) & 0x3f) : c);
3266 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3267 canonicalised_key: ;
3269 if (flags & REFCOUNTED_HE_KEY_UTF8)
3270 hekflags |= HVhek_UTF8;
3272 PERL_HASH(hash, keypv, keylen);
3275 he = (struct refcounted_he*)
3276 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3280 he = (struct refcounted_he*)
3281 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3285 he->refcounted_he_next = parent;
3288 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3289 he->refcounted_he_val.refcounted_he_u_len = value_len;
3290 } else if (value_type == HVrhek_IV) {
3291 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3292 } else if (value_type == HVrhek_UV) {
3293 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3297 he->refcounted_he_hash = hash;
3298 he->refcounted_he_keylen = keylen;
3299 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3301 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3304 he->refcounted_he_data[0] = hekflags;
3305 he->refcounted_he_refcnt = 1;
3311 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3313 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3314 of a string/length pair.
3319 struct refcounted_he *
3320 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3321 const char *key, U32 hash, SV *value, U32 flags)
3323 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3324 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3328 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3330 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3336 struct refcounted_he *
3337 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3338 SV *key, U32 hash, SV *value, U32 flags)
3342 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3343 if (flags & REFCOUNTED_HE_KEY_UTF8)
3344 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3346 keypv = SvPV_const(key, keylen);
3348 flags |= REFCOUNTED_HE_KEY_UTF8;
3349 if (!hash && SvIsCOW_shared_hash(key))
3350 hash = SvSHARED_HASH(key);
3351 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3355 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3357 Decrements the reference count of a C<refcounted_he> by one. If the
3358 reference count reaches zero the structure's memory is freed, which
3359 (recursively) causes a reduction of its parent C<refcounted_he>'s
3360 reference count. It is safe to pass a null pointer to this function:
3361 no action occurs in this case.
3367 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3369 PERL_UNUSED_CONTEXT;
3372 struct refcounted_he *copy;
3376 new_count = --he->refcounted_he_refcnt;
3377 HINTS_REFCNT_UNLOCK;
3383 #ifndef USE_ITHREADS
3384 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3387 he = he->refcounted_he_next;
3388 PerlMemShared_free(copy);
3393 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3395 Increment the reference count of a C<refcounted_he>. The pointer to the
3396 C<refcounted_he> is also returned. It is safe to pass a null pointer
3397 to this function: no action occurs and a null pointer is returned.
3402 struct refcounted_he *
3403 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3408 he->refcounted_he_refcnt++;
3409 HINTS_REFCNT_UNLOCK;
3415 =for apidoc cop_fetch_label
3417 Returns the label attached to a cop.
3418 The flags pointer may be set to C<SVf_UTF8> or 0.
3423 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3426 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3427 struct refcounted_he *const chain = cop->cop_hints_hash;
3429 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3434 if (chain->refcounted_he_keylen != 1)
3436 if (*REF_HE_KEY(chain) != ':')
3439 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3441 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3444 /* Stop anyone trying to really mess us up by adding their own value for
3446 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3447 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3451 *len = chain->refcounted_he_val.refcounted_he_u_len;
3453 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3454 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3456 return chain->refcounted_he_data + 1;
3460 =for apidoc cop_store_label
3462 Save a label into a C<cop_hints_hash>. You need to set flags to C<SVf_UTF8>
3469 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3473 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3475 if (flags & ~(SVf_UTF8))
3476 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3478 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3479 if (flags & SVf_UTF8)
3482 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3486 =for apidoc hv_assert
3488 Check that a hash is in an internally consistent state.
3496 Perl_hv_assert(pTHX_ HV *hv)
3501 int placeholders = 0;
3504 const I32 riter = HvRITER_get(hv);
3505 HE *eiter = HvEITER_get(hv);
3507 PERL_ARGS_ASSERT_HV_ASSERT;
3509 (void)hv_iterinit(hv);
3511 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3512 /* sanity check the values */
3513 if (HeVAL(entry) == &PL_sv_placeholder)
3517 /* sanity check the keys */
3518 if (HeSVKEY(entry)) {
3519 NOOP; /* Don't know what to check on SV keys. */
3520 } else if (HeKUTF8(entry)) {
3522 if (HeKWASUTF8(entry)) {
3523 PerlIO_printf(Perl_debug_log,
3524 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3525 (int) HeKLEN(entry), HeKEY(entry));
3528 } else if (HeKWASUTF8(entry))
3531 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3532 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3533 const int nhashkeys = HvUSEDKEYS(hv);
3534 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3536 if (nhashkeys != real) {
3537 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3540 if (nhashplaceholders != placeholders) {
3541 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3545 if (withflags && ! HvHASKFLAGS(hv)) {
3546 PerlIO_printf(Perl_debug_log,
3547 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3552 sv_dump(MUTABLE_SV(hv));
3554 HvRITER_set(hv, riter); /* Restore hash iterator state */
3555 HvEITER_set(hv, eiter);
3562 * c-indentation-style: bsd
3564 * indent-tabs-mode: nil
3567 * ex: set ts=8 sts=4 sw=4 et: