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
21 A HV structure represents a Perl hash. It consists mainly of an array
22 of pointers, each of which points to a linked list of HE structures. The
23 array is indexed by the hash function of the key, so each linked list
24 represents all the hash entries with the same hash value. Each HE contains
25 a pointer to the actual value, plus a pointer to a HEK structure which
26 holds the key and hash value.
34 #define PERL_HASH_INTERNAL_ACCESS
37 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
38 #define HV_FILL_THRESHOLD 31
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)
54 void ** const root = &PL_body_roots[HE_SVSLOT];
57 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
64 #define new_HE() new_he()
67 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
68 PL_body_roots[HE_SVSLOT] = p; \
76 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
78 const int flags_masked = flags & HVhek_MASK;
82 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
84 Newx(k, HEK_BASESIZE + len + 2, char);
86 Copy(str, HEK_KEY(hek), len, char);
87 HEK_KEY(hek)[len] = 0;
90 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
92 if (flags & HVhek_FREEKEY)
97 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
101 Perl_free_tied_hv_pool(pTHX)
103 HE *he = PL_hv_fetch_ent_mh;
106 Safefree(HeKEY_hek(he));
110 PL_hv_fetch_ent_mh = NULL;
113 #if defined(USE_ITHREADS)
115 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
119 PERL_ARGS_ASSERT_HEK_DUP;
120 PERL_UNUSED_ARG(param);
125 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
127 /* We already shared this hash key. */
128 (void)share_hek_hek(shared);
132 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
133 HEK_HASH(source), HEK_FLAGS(source));
134 ptr_table_store(PL_ptr_table, source, shared);
140 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
144 PERL_ARGS_ASSERT_HE_DUP;
148 /* look for it in the table first */
149 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
153 /* create anew and remember what it is */
155 ptr_table_store(PL_ptr_table, e, ret);
157 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
158 if (HeKLEN(e) == HEf_SVKEY) {
160 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
161 HeKEY_hek(ret) = (HEK*)k;
162 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
165 /* This is hek_dup inlined, which seems to be important for speed
167 HEK * const source = HeKEY_hek(e);
168 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
171 /* We already shared this hash key. */
172 (void)share_hek_hek(shared);
176 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
177 HEK_HASH(source), HEK_FLAGS(source));
178 ptr_table_store(PL_ptr_table, source, shared);
180 HeKEY_hek(ret) = shared;
183 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
185 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
188 #endif /* USE_ITHREADS */
191 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
194 SV * const sv = sv_newmortal();
196 PERL_ARGS_ASSERT_HV_NOTALLOWED;
198 if (!(flags & HVhek_FREEKEY)) {
199 sv_setpvn(sv, key, klen);
202 /* Need to free saved eventually assign to mortal SV */
203 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
204 sv_usepvn(sv, (char *) key, klen);
206 if (flags & HVhek_UTF8) {
209 Perl_croak(aTHX_ msg, SVfARG(sv));
212 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
218 Stores an SV in a hash. The hash key is specified as C<key> and the
219 absolute value of C<klen> is the length of the key. If C<klen> is
220 negative the key is assumed to be in UTF-8-encoded Unicode. The
221 C<hash> parameter is the precomputed hash value; if it is zero then
222 Perl will compute it.
224 The return value will be
225 C<NULL> if the operation failed or if the value did not need to be actually
226 stored within the hash (as in the case of tied hashes). Otherwise it can
227 be dereferenced to get the original C<SV*>. Note that the caller is
228 responsible for suitably incrementing the reference count of C<val> before
229 the call, and decrementing it if the function returned C<NULL>. Effectively
230 a successful C<hv_store> takes ownership of one reference to C<val>. This is
231 usually what you want; a newly created SV has a reference count of one, so
232 if all your code does is create SVs then store them in a hash, C<hv_store>
233 will own the only reference to the new SV, and your code doesn't need to do
234 anything further to tidy up. C<hv_store> is not implemented as a call to
235 C<hv_store_ent>, and does not create a temporary SV for the key, so if your
236 key data is not already in SV form then use C<hv_store> in preference to
239 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
240 information on how to use this function on tied hashes.
242 =for apidoc hv_store_ent
244 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
245 parameter is the precomputed hash value; if it is zero then Perl will
246 compute it. The return value is the new hash entry so created. It will be
247 C<NULL> if the operation failed or if the value did not need to be actually
248 stored within the hash (as in the case of tied hashes). Otherwise the
249 contents of the return value can be accessed using the C<He?> macros
250 described here. Note that the caller is responsible for suitably
251 incrementing the reference count of C<val> before the call, and
252 decrementing it if the function returned NULL. Effectively a successful
253 C<hv_store_ent> takes ownership of one reference to C<val>. This is
254 usually what you want; a newly created SV has a reference count of one, so
255 if all your code does is create SVs then store them in a hash, C<hv_store>
256 will own the only reference to the new SV, and your code doesn't need to do
257 anything further to tidy up. Note that C<hv_store_ent> only reads the C<key>;
258 unlike C<val> it does not take ownership of it, so maintaining the correct
259 reference count on C<key> is entirely the caller's responsibility. C<hv_store>
260 is not implemented as a call to C<hv_store_ent>, and does not create a temporary
261 SV for the key, so if your key data is not already in SV form then use
262 C<hv_store> in preference to C<hv_store_ent>.
264 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
265 information on how to use this function on tied hashes.
267 =for apidoc hv_exists
269 Returns a boolean indicating whether the specified hash key exists. The
270 absolute value of C<klen> is the length of the key. If C<klen> is
271 negative the key is assumed to be in UTF-8-encoded Unicode.
275 Returns the SV which corresponds to the specified key in the hash.
276 The absolute value of C<klen> is the length of the key. If C<klen> is
277 negative the key is assumed to be in UTF-8-encoded Unicode. If
278 C<lval> is set then the fetch will be part of a store. This means that if
279 there is no value in the hash associated with the given key, then one is
280 created and a pointer to it is returned. The C<SV*> it points to can be
281 assigned to. But always check that the
282 return value is non-null before dereferencing it to an C<SV*>.
284 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
285 information on how to use this function on tied hashes.
287 =for apidoc hv_exists_ent
289 Returns a boolean indicating whether
290 the specified hash key exists. C<hash>
291 can be a valid precomputed hash value, or 0 to ask for it to be
297 /* returns an HE * structure with the all fields set */
298 /* note that hent_val will be a mortal sv for MAGICAL hashes */
300 =for apidoc hv_fetch_ent
302 Returns the hash entry which corresponds to the specified key in the hash.
303 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
304 if you want the function to compute it. IF C<lval> is set then the fetch
305 will be part of a store. Make sure the return value is non-null before
306 accessing it. The return value when C<hv> is a tied hash is a pointer to a
307 static location, so be sure to make a copy of the structure if you need to
310 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
311 information on how to use this function on tied hashes.
316 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
318 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
319 const int action, SV *val, const U32 hash)
324 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
333 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
337 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
338 int flags, int action, SV *val, U32 hash)
347 const int return_svp = action & HV_FETCH_JUST_SV;
348 HEK *keysv_hek = NULL;
352 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
355 assert(SvTYPE(hv) == SVt_PVHV);
357 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
359 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
360 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
361 if (uf->uf_set == NULL) {
362 SV* obj = mg->mg_obj;
365 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
366 ((flags & HVhek_UTF8)
370 mg->mg_obj = keysv; /* pass key */
371 uf->uf_index = action; /* pass action */
372 magic_getuvar(MUTABLE_SV(hv), mg);
373 keysv = mg->mg_obj; /* may have changed */
376 /* If the key may have changed, then we need to invalidate
377 any passed-in computed hash value. */
383 if (flags & HVhek_FREEKEY)
385 key = SvPV_const(keysv, klen);
386 is_utf8 = (SvUTF8(keysv) != 0);
387 if (SvIsCOW_shared_hash(keysv)) {
388 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
390 flags = is_utf8 ? HVhek_UTF8 : 0;
393 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
396 if (action & HV_DELETE) {
397 return (void *) hv_delete_common(hv, keysv, key, klen,
398 flags, action, hash);
401 xhv = (XPVHV*)SvANY(hv);
403 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
404 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
405 || SvGMAGICAL((const SV *)hv))
407 /* FIXME should be able to skimp on the HE/HEK here when
408 HV_FETCH_JUST_SV is true. */
410 keysv = newSVpvn_utf8(key, klen, is_utf8);
412 keysv = newSVsv(keysv);
415 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
417 /* grab a fake HE/HEK pair from the pool or make a new one */
418 entry = PL_hv_fetch_ent_mh;
420 PL_hv_fetch_ent_mh = HeNEXT(entry);
424 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
425 HeKEY_hek(entry) = (HEK*)k;
427 HeNEXT(entry) = NULL;
428 HeSVKEY_set(entry, keysv);
430 sv_upgrade(sv, SVt_PVLV);
432 /* so we can free entry when freeing sv */
433 LvTARG(sv) = MUTABLE_SV(entry);
435 /* XXX remove at some point? */
436 if (flags & HVhek_FREEKEY)
440 return entry ? (void *) &HeVAL(entry) : NULL;
442 return (void *) entry;
444 #ifdef ENV_IS_CASELESS
445 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
447 for (i = 0; i < klen; ++i)
448 if (isLOWER(key[i])) {
449 /* Would be nice if we had a routine to do the
450 copy and upercase in a single pass through. */
451 const char * const nkey = strupr(savepvn(key,klen));
452 /* Note that this fetch is for nkey (the uppercased
453 key) whereas the store is for key (the original) */
454 void *result = hv_common(hv, NULL, nkey, klen,
455 HVhek_FREEKEY, /* free nkey */
456 0 /* non-LVAL fetch */
457 | HV_DISABLE_UVAR_XKEY
460 0 /* compute hash */);
461 if (!result && (action & HV_FETCH_LVALUE)) {
462 /* This call will free key if necessary.
463 Do it this way to encourage compiler to tail
465 result = hv_common(hv, keysv, key, klen, flags,
467 | HV_DISABLE_UVAR_XKEY
471 if (flags & HVhek_FREEKEY)
479 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
480 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
481 || SvGMAGICAL((const SV *)hv)) {
482 /* I don't understand why hv_exists_ent has svret and sv,
483 whereas hv_exists only had one. */
484 SV * const svret = sv_newmortal();
487 if (keysv || is_utf8) {
489 keysv = newSVpvn_utf8(key, klen, TRUE);
491 keysv = newSVsv(keysv);
493 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
495 mg_copy(MUTABLE_SV(hv), sv, key, klen);
497 if (flags & HVhek_FREEKEY)
500 MAGIC * const mg = mg_find(sv, PERL_MAGIC_tiedelem);
502 magic_existspack(svret, mg);
504 /* This cast somewhat evil, but I'm merely using NULL/
505 not NULL to return the boolean exists.
506 And I know hv is not NULL. */
507 return SvTRUE(svret) ? (void *)hv : NULL;
509 #ifdef ENV_IS_CASELESS
510 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
511 /* XXX This code isn't UTF8 clean. */
512 char * const keysave = (char * const)key;
513 /* Will need to free this, so set FREEKEY flag. */
514 key = savepvn(key,klen);
515 key = (const char*)strupr((char*)key);
520 if (flags & HVhek_FREEKEY) {
523 flags |= HVhek_FREEKEY;
527 else if (action & HV_FETCH_ISSTORE) {
530 hv_magic_check (hv, &needs_copy, &needs_store);
532 const bool save_taint = TAINT_get;
533 if (keysv || is_utf8) {
535 keysv = newSVpvn_utf8(key, klen, TRUE);
538 TAINT_set(SvTAINTED(keysv));
539 keysv = sv_2mortal(newSVsv(keysv));
540 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
542 mg_copy(MUTABLE_SV(hv), val, key, klen);
545 TAINT_IF(save_taint);
546 #ifdef NO_TAINT_SUPPORT
547 PERL_UNUSED_VAR(save_taint);
550 if (flags & HVhek_FREEKEY)
554 #ifdef ENV_IS_CASELESS
555 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
556 /* XXX This code isn't UTF8 clean. */
557 const char *keysave = key;
558 /* Will need to free this, so set FREEKEY flag. */
559 key = savepvn(key,klen);
560 key = (const char*)strupr((char*)key);
565 if (flags & HVhek_FREEKEY) {
568 flags |= HVhek_FREEKEY;
576 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
577 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
578 || (SvRMAGICAL((const SV *)hv)
579 && mg_find((const SV *)hv, PERL_MAGIC_env))
584 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
586 HvARRAY(hv) = (HE**)array;
588 #ifdef DYNAMIC_ENV_FETCH
589 else if (action & HV_FETCH_ISEXISTS) {
590 /* for an %ENV exists, if we do an insert it's by a recursive
591 store call, so avoid creating HvARRAY(hv) right now. */
595 /* XXX remove at some point? */
596 if (flags & HVhek_FREEKEY)
603 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
604 char * const keysave = (char *)key;
605 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
609 flags &= ~HVhek_UTF8;
610 if (key != keysave) {
611 if (flags & HVhek_FREEKEY)
613 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
614 /* If the caller calculated a hash, it was on the sequence of
615 octets that are the UTF-8 form. We've now changed the sequence
616 of octets stored to that of the equivalent byte representation,
617 so the hash we need is different. */
622 if (keysv && (SvIsCOW_shared_hash(keysv))) {
624 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
625 hash = SvSHARED_HASH(keysv);
628 PERL_HASH(hash, key, klen);
630 masked_flags = (flags & HVhek_MASK);
632 #ifdef DYNAMIC_ENV_FETCH
633 if (!HvARRAY(hv)) entry = NULL;
637 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
644 /* keysv is actually a HEK in disguise, so we can match just by
645 * comparing the HEK pointers in the HE chain. There is a slight
646 * caveat: on something like "\x80", which has both plain and utf8
647 * representations, perl's hashes do encoding-insensitive lookups,
648 * but preserve the encoding of the stored key. Thus a particular
649 * key could map to two different HEKs in PL_strtab. We only
650 * conclude 'not found' if all the flags are the same; otherwise
651 * we fall back to a full search (this should only happen in rare
654 int keysv_flags = HEK_FLAGS(keysv_hek);
655 HE *orig_entry = entry;
657 for (; entry; entry = HeNEXT(entry)) {
658 HEK *hek = HeKEY_hek(entry);
659 if (hek == keysv_hek)
661 if (HEK_FLAGS(hek) != keysv_flags)
662 break; /* need to do full match */
666 /* failed on shortcut - do full search loop */
670 for (; entry; entry = HeNEXT(entry)) {
671 if (HeHASH(entry) != hash) /* strings can't be equal */
673 if (HeKLEN(entry) != (I32)klen)
675 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
677 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
681 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
682 if (HeKFLAGS(entry) != masked_flags) {
683 /* We match if HVhek_UTF8 bit in our flags and hash key's
684 match. But if entry was set previously with HVhek_WASUTF8
685 and key now doesn't (or vice versa) then we should change
686 the key's flag, as this is assignment. */
687 if (HvSHAREKEYS(hv)) {
688 /* Need to swap the key we have for a key with the flags we
689 need. As keys are shared we can't just write to the
690 flag, so we share the new one, unshare the old one. */
691 HEK * const new_hek = share_hek_flags(key, klen, hash,
693 unshare_hek (HeKEY_hek(entry));
694 HeKEY_hek(entry) = new_hek;
696 else if (hv == PL_strtab) {
697 /* PL_strtab is usually the only hash without HvSHAREKEYS,
698 so putting this test here is cheap */
699 if (flags & HVhek_FREEKEY)
701 Perl_croak(aTHX_ S_strtab_error,
702 action & HV_FETCH_LVALUE ? "fetch" : "store");
705 HeKFLAGS(entry) = masked_flags;
706 if (masked_flags & HVhek_ENABLEHVKFLAGS)
709 if (HeVAL(entry) == &PL_sv_placeholder) {
710 /* yes, can store into placeholder slot */
711 if (action & HV_FETCH_LVALUE) {
713 /* This preserves behaviour with the old hv_fetch
714 implementation which at this point would bail out
715 with a break; (at "if we find a placeholder, we
716 pretend we haven't found anything")
718 That break mean that if a placeholder were found, it
719 caused a call into hv_store, which in turn would
720 check magic, and if there is no magic end up pretty
721 much back at this point (in hv_store's code). */
724 /* LVAL fetch which actually needs a store. */
726 HvPLACEHOLDERS(hv)--;
729 if (val != &PL_sv_placeholder)
730 HvPLACEHOLDERS(hv)--;
733 } else if (action & HV_FETCH_ISSTORE) {
734 SvREFCNT_dec(HeVAL(entry));
737 } else if (HeVAL(entry) == &PL_sv_placeholder) {
738 /* if we find a placeholder, we pretend we haven't found
742 if (flags & HVhek_FREEKEY)
745 return (void *) &HeVAL(entry);
751 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
752 if (!(action & HV_FETCH_ISSTORE)
753 && SvRMAGICAL((const SV *)hv)
754 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
756 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
758 sv = newSVpvn(env,len);
760 return hv_common(hv, keysv, key, klen, flags,
761 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
767 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
768 hv_notallowed(flags, key, klen,
769 "Attempt to access disallowed key '%"SVf"' in"
770 " a restricted hash");
772 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
773 /* Not doing some form of store, so return failure. */
774 if (flags & HVhek_FREEKEY)
778 if (action & HV_FETCH_LVALUE) {
779 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
781 /* At this point the old hv_fetch code would call to hv_store,
782 which in turn might do some tied magic. So we need to make that
783 magic check happen. */
784 /* gonna assign to this, so it better be there */
785 /* If a fetch-as-store fails on the fetch, then the action is to
786 recurse once into "hv_store". If we didn't do this, then that
787 recursive call would call the key conversion routine again.
788 However, as we replace the original key with the converted
789 key, this would result in a double conversion, which would show
790 up as a bug if the conversion routine is not idempotent.
791 Hence the use of HV_DISABLE_UVAR_XKEY. */
792 return hv_common(hv, keysv, key, klen, flags,
793 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
795 /* XXX Surely that could leak if the fetch-was-store fails?
796 Just like the hv_fetch. */
800 /* Welcome to hv_store... */
803 /* Not sure if we can get here. I think the only case of oentry being
804 NULL is for %ENV with dynamic env fetch. But that should disappear
805 with magic in the previous code. */
808 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
810 HvARRAY(hv) = (HE**)array;
813 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
816 /* share_hek_flags will do the free for us. This might be considered
819 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
820 else if (hv == PL_strtab) {
821 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
822 this test here is cheap */
823 if (flags & HVhek_FREEKEY)
825 Perl_croak(aTHX_ S_strtab_error,
826 action & HV_FETCH_LVALUE ? "fetch" : "store");
828 else /* gotta do the real thing */
829 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
832 if (!*oentry && SvOOK(hv)) {
833 /* initial entry, and aux struct present. */
834 struct xpvhv_aux *const aux = HvAUX(hv);
835 if (aux->xhv_fill_lazy)
836 ++aux->xhv_fill_lazy;
839 #ifdef PERL_HASH_RANDOMIZE_KEYS
840 /* This logic semi-randomizes the insert order in a bucket.
841 * Either we insert into the top, or the slot below the top,
842 * making it harder to see if there is a collision. We also
843 * reset the iterator randomizer if there is one.
845 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
847 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
848 if ( PL_hash_rand_bits & 1 ) {
849 HeNEXT(entry) = HeNEXT(*oentry);
850 HeNEXT(*oentry) = entry;
852 HeNEXT(entry) = *oentry;
858 HeNEXT(entry) = *oentry;
861 #ifdef PERL_HASH_RANDOMIZE_KEYS
863 /* Currently this makes various tests warn in annoying ways.
864 * So Silenced for now. - Yves | bogus end of comment =>* /
865 if (HvAUX(hv)->xhv_riter != -1) {
866 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
867 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
872 if (PL_HASH_RAND_BITS_ENABLED) {
873 if (PL_HASH_RAND_BITS_ENABLED == 1)
874 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
875 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
877 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
881 if (val == &PL_sv_placeholder)
882 HvPLACEHOLDERS(hv)++;
883 if (masked_flags & HVhek_ENABLEHVKFLAGS)
886 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
887 if ( DO_HSPLIT(xhv) ) {
888 const STRLEN oldsize = xhv->xhv_max + 1;
889 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
891 if (items /* hash has placeholders */
892 && !SvREADONLY(hv) /* but is not a restricted hash */) {
893 /* If this hash previously was a "restricted hash" and had
894 placeholders, but the "restricted" flag has been turned off,
895 then the placeholders no longer serve any useful purpose.
896 However, they have the downsides of taking up RAM, and adding
897 extra steps when finding used values. It's safe to clear them
898 at this point, even though Storable rebuilds restricted hashes by
899 putting in all the placeholders (first) before turning on the
900 readonly flag, because Storable always pre-splits the hash.
901 If we're lucky, then we may clear sufficient placeholders to
902 avoid needing to split the hash at all. */
903 clear_placeholders(hv, items);
905 hsplit(hv, oldsize, oldsize * 2);
907 hsplit(hv, oldsize, oldsize * 2);
911 return entry ? (void *) &HeVAL(entry) : NULL;
913 return (void *) entry;
917 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
919 const MAGIC *mg = SvMAGIC(hv);
921 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
926 if (isUPPER(mg->mg_type)) {
928 if (mg->mg_type == PERL_MAGIC_tied) {
929 *needs_store = FALSE;
930 return; /* We've set all there is to set. */
933 mg = mg->mg_moremagic;
938 =for apidoc hv_scalar
940 Evaluates the hash in scalar context and returns the result. Handles magic
941 when the hash is tied.
947 Perl_hv_scalar(pTHX_ HV *hv)
951 PERL_ARGS_ASSERT_HV_SCALAR;
953 if (SvRMAGICAL(hv)) {
954 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
956 return magic_scalarpack(hv, mg);
960 if (HvTOTALKEYS((const HV *)hv))
961 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
962 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
970 =for apidoc hv_delete
972 Deletes a key/value pair in the hash. The value's SV is removed from
973 the hash, made mortal, and returned to the caller. The absolute
974 value of C<klen> is the length of the key. If C<klen> is negative the
975 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
976 will normally be zero; if set to C<G_DISCARD> then C<NULL> will be returned.
977 C<NULL> will also be returned if the key is not found.
979 =for apidoc hv_delete_ent
981 Deletes a key/value pair in the hash. The value SV is removed from the hash,
982 made mortal, and returned to the caller. The C<flags> value will normally be
983 zero; if set to C<G_DISCARD> then C<NULL> will be returned. C<NULL> will also
984 be returned if the key is not found. C<hash> can be a valid precomputed hash
985 value, or 0 to ask for it to be computed.
991 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
992 int k_flags, I32 d_flags, U32 hash)
999 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
1001 HEK *keysv_hek = NULL;
1002 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1007 if (SvRMAGICAL(hv)) {
1010 hv_magic_check (hv, &needs_copy, &needs_store);
1014 entry = (HE *) hv_common(hv, keysv, key, klen,
1015 k_flags & ~HVhek_FREEKEY,
1016 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1018 sv = entry ? HeVAL(entry) : NULL;
1020 if (SvMAGICAL(sv)) {
1024 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1025 /* No longer an element */
1026 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1029 return NULL; /* element cannot be deleted */
1031 #ifdef ENV_IS_CASELESS
1032 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1033 /* XXX This code isn't UTF8 clean. */
1034 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1035 if (k_flags & HVhek_FREEKEY) {
1038 key = strupr(SvPVX(keysv));
1047 xhv = (XPVHV*)SvANY(hv);
1051 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1052 const char * const keysave = key;
1053 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1056 k_flags |= HVhek_UTF8;
1058 k_flags &= ~HVhek_UTF8;
1059 if (key != keysave) {
1060 if (k_flags & HVhek_FREEKEY) {
1061 /* This shouldn't happen if our caller does what we expect,
1062 but strictly the API allows it. */
1065 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1067 HvHASKFLAGS_on(MUTABLE_SV(hv));
1070 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1071 if (HvSHAREKEYS(hv))
1072 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1073 hash = SvSHARED_HASH(keysv);
1076 PERL_HASH(hash, key, klen);
1078 masked_flags = (k_flags & HVhek_MASK);
1080 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1087 /* keysv is actually a HEK in disguise, so we can match just by
1088 * comparing the HEK pointers in the HE chain. There is a slight
1089 * caveat: on something like "\x80", which has both plain and utf8
1090 * representations, perl's hashes do encoding-insensitive lookups,
1091 * but preserve the encoding of the stored key. Thus a particular
1092 * key could map to two different HEKs in PL_strtab. We only
1093 * conclude 'not found' if all the flags are the same; otherwise
1094 * we fall back to a full search (this should only happen in rare
1097 int keysv_flags = HEK_FLAGS(keysv_hek);
1099 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1100 HEK *hek = HeKEY_hek(entry);
1101 if (hek == keysv_hek)
1103 if (HEK_FLAGS(hek) != keysv_flags)
1104 break; /* need to do full match */
1108 /* failed on shortcut - do full search loop */
1109 oentry = first_entry;
1113 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1114 if (HeHASH(entry) != hash) /* strings can't be equal */
1116 if (HeKLEN(entry) != (I32)klen)
1118 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1120 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1124 if (hv == PL_strtab) {
1125 if (k_flags & HVhek_FREEKEY)
1127 Perl_croak(aTHX_ S_strtab_error, "delete");
1130 /* if placeholder is here, it's already been deleted.... */
1131 if (HeVAL(entry) == &PL_sv_placeholder) {
1132 if (k_flags & HVhek_FREEKEY)
1136 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1137 hv_notallowed(k_flags, key, klen,
1138 "Attempt to delete readonly key '%"SVf"' from"
1139 " a restricted hash");
1141 if (k_flags & HVhek_FREEKEY)
1144 /* If this is a stash and the key ends with ::, then someone is
1145 * deleting a package.
1147 if (HeVAL(entry) && HvENAME_get(hv)) {
1148 gv = (GV *)HeVAL(entry);
1149 if (keysv) key = SvPV(keysv, klen);
1151 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1153 (klen == 1 && key[0] == ':')
1155 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1156 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1157 && HvENAME_get(stash)) {
1158 /* A previous version of this code checked that the
1159 * GV was still in the symbol table by fetching the
1160 * GV with its name. That is not necessary (and
1161 * sometimes incorrect), as HvENAME cannot be set
1162 * on hv if it is not in the symtab. */
1164 /* Hang on to it for a bit. */
1165 SvREFCNT_inc_simple_void_NN(
1166 sv_2mortal((SV *)gv)
1169 else if (klen == 3 && strnEQ(key, "ISA", 3) && GvAV(gv)) {
1171 MAGIC *mg = mg_find((SV*)isa, PERL_MAGIC_isa);
1175 if (mg->mg_obj == (SV*)gv) {
1176 /* This is the only stash this ISA was used for.
1177 * The isaelem magic asserts if there's no
1178 * isa magic on the array, so explicitly
1179 * remove the magic on both the array and its
1180 * elements. @ISA shouldn't be /too/ large.
1185 end = svp + AvFILLp(isa)+1;
1188 mg_free_type(*svp, PERL_MAGIC_isaelem);
1191 mg_free_type((SV*)GvAV(gv), PERL_MAGIC_isa);
1194 /* mg_obj is an array of stashes
1195 Note that the array doesn't keep a reference
1196 count on the stashes.
1198 AV *av = (AV*)mg->mg_obj;
1203 assert(SvTYPE(mg->mg_obj) == SVt_PVAV);
1205 /* remove the stash from the magic array */
1206 arrayp = svp = AvARRAY(av);
1207 items = AvFILLp(av) + 1;
1209 assert(*arrayp == (SV *)gv);
1211 /* avoid a double free on the last stash */
1213 /* The magic isn't MGf_REFCOUNTED, so release
1214 * the array manually.
1216 SvREFCNT_dec_NN(av);
1221 if (*svp == (SV*)gv)
1225 index = svp - arrayp;
1226 assert(index >= 0 && index <= AvFILLp(av));
1227 if (index < AvFILLp(av)) {
1228 arrayp[index] = arrayp[AvFILLp(av)];
1230 arrayp[AvFILLp(av)] = NULL;
1238 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1239 HeVAL(entry) = &PL_sv_placeholder;
1241 /* deletion of method from stash */
1242 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1244 mro_method_changed_in(hv);
1248 * If a restricted hash, rather than really deleting the entry, put
1249 * a placeholder there. This marks the key as being "approved", so
1250 * we can still access via not-really-existing key without raising
1254 /* We'll be saving this slot, so the number of allocated keys
1255 * doesn't go down, but the number placeholders goes up */
1256 HvPLACEHOLDERS(hv)++;
1258 *oentry = HeNEXT(entry);
1259 if(!*first_entry && SvOOK(hv)) {
1260 /* removed last entry, and aux struct present. */
1261 struct xpvhv_aux *const aux = HvAUX(hv);
1262 if (aux->xhv_fill_lazy)
1263 --aux->xhv_fill_lazy;
1265 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1268 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1269 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1270 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1271 hv_free_ent(hv, entry);
1273 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1274 if (xhv->xhv_keys == 0)
1275 HvHASKFLAGS_off(hv);
1278 if (d_flags & G_DISCARD) {
1283 if (mro_changes == 1) mro_isa_changed_in(hv);
1284 else if (mro_changes == 2)
1285 mro_package_moved(NULL, stash, gv, 1);
1291 if (SvREADONLY(hv)) {
1292 hv_notallowed(k_flags, key, klen,
1293 "Attempt to delete disallowed key '%"SVf"' from"
1294 " a restricted hash");
1297 if (k_flags & HVhek_FREEKEY)
1304 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1307 char *a = (char*) HvARRAY(hv);
1311 /* already have an HvAUX(hv) so we have to move it */
1313 /* no HvAUX() but array we are going to allocate is large enough
1314 * there is no point in saving the space for the iterator, and
1315 * speeds up later traversals. */
1316 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1319 PERL_ARGS_ASSERT_HSPLIT;
1322 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1323 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1329 #ifdef PERL_HASH_RANDOMIZE_KEYS
1330 /* the idea of this is that we create a "random" value by hashing the address of
1331 * the array, we then use the low bit to decide if we insert at the top, or insert
1332 * second from top. After each such insert we rotate the hashed value. So we can
1333 * use the same hashed value over and over, and in normal build environments use
1334 * very few ops to do so. ROTL32() should produce a single machine operation. */
1335 if (PL_HASH_RAND_BITS_ENABLED) {
1336 if (PL_HASH_RAND_BITS_ENABLED == 1)
1337 PL_hash_rand_bits += ptr_hash((PTRV)a);
1338 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1341 HvARRAY(hv) = (HE**) a;
1342 HvMAX(hv) = newsize - 1;
1343 /* before we zero the newly added memory, we
1344 * need to deal with the aux struct that may be there
1345 * or have been allocated by us*/
1347 struct xpvhv_aux *const dest
1348 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1350 /* alread have an aux, copy the old one in place. */
1351 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1352 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1353 #ifdef PERL_HASH_RANDOMIZE_KEYS
1354 dest->xhv_rand = (U32)PL_hash_rand_bits;
1356 /* For now, just reset the lazy fill counter.
1357 It would be possible to update the counter in the code below
1359 dest->xhv_fill_lazy = 0;
1361 /* no existing aux structure, but we allocated space for one
1362 * so initialize it properly. This unrolls hv_auxinit() a bit,
1363 * since we have to do the realloc anyway. */
1364 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1365 #ifdef PERL_HASH_RANDOMIZE_KEYS
1366 dest->xhv_rand = (U32)PL_hash_rand_bits;
1368 /* this is the "non realloc" part of the hv_auxinit() */
1369 (void)hv_auxinit_internal(dest);
1370 /* Turn on the OOK flag */
1374 /* now we can safely clear the second half */
1375 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1377 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1383 HE **oentry = aep + i;
1386 if (!entry) /* non-existent */
1389 U32 j = (HeHASH(entry) & newsize);
1391 *oentry = HeNEXT(entry);
1392 #ifdef PERL_HASH_RANDOMIZE_KEYS
1393 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1394 * insert to top, otherwise rotate the bucket rand 1 bit,
1395 * and use the new low bit to decide if we insert at top,
1396 * or next from top. IOW, we only rotate on a collision.*/
1397 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1398 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1399 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1400 if (PL_hash_rand_bits & 1) {
1401 HeNEXT(entry)= HeNEXT(aep[j]);
1402 HeNEXT(aep[j])= entry;
1404 /* Note, this is structured in such a way as the optimizer
1405 * should eliminate the duplicated code here and below without
1406 * us needing to explicitly use a goto. */
1407 HeNEXT(entry) = aep[j];
1413 /* see comment above about duplicated code */
1414 HeNEXT(entry) = aep[j];
1419 oentry = &HeNEXT(entry);
1423 } while (i++ < oldsize);
1427 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1429 XPVHV* xhv = (XPVHV*)SvANY(hv);
1430 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1434 PERL_ARGS_ASSERT_HV_KSPLIT;
1436 newsize = (I32) newmax; /* possible truncation here */
1437 if (newsize != newmax || newmax <= oldsize)
1439 while ((newsize & (1 + ~newsize)) != newsize) {
1440 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1442 if (newsize < newmax)
1444 if (newsize < newmax)
1445 return; /* overflow detection */
1447 a = (char *) HvARRAY(hv);
1449 hsplit(hv, oldsize, newsize);
1451 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1452 xhv->xhv_max = --newsize;
1453 HvARRAY(hv) = (HE **) a;
1457 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1458 * as tied hashes could play silly buggers and mess us around. We will
1459 * do the right thing during hv_store() afterwards, but still - Yves */
1460 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1461 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1462 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1463 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1465 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1466 hv_max = hv_max / 2; \
1468 HvMAX(hv) = hv_max; \
1473 Perl_newHVhv(pTHX_ HV *ohv)
1476 HV * const hv = newHV();
1479 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1481 hv_max = HvMAX(ohv);
1483 if (!SvMAGICAL((const SV *)ohv)) {
1484 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1486 const bool shared = !!HvSHAREKEYS(ohv);
1487 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1489 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1492 /* In each bucket... */
1493 for (i = 0; i <= hv_max; i++) {
1495 HE *oent = oents[i];
1502 /* Copy the linked list of entries. */
1503 for (; oent; oent = HeNEXT(oent)) {
1504 const U32 hash = HeHASH(oent);
1505 const char * const key = HeKEY(oent);
1506 const STRLEN len = HeKLEN(oent);
1507 const int flags = HeKFLAGS(oent);
1508 HE * const ent = new_HE();
1509 SV *const val = HeVAL(oent);
1511 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1513 = shared ? share_hek_flags(key, len, hash, flags)
1514 : save_hek_flags(key, len, hash, flags);
1525 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1529 /* Iterate over ohv, copying keys and values one at a time. */
1531 const I32 riter = HvRITER_get(ohv);
1532 HE * const eiter = HvEITER_get(ohv);
1533 STRLEN hv_keys = HvTOTALKEYS(ohv);
1535 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1538 while ((entry = hv_iternext_flags(ohv, 0))) {
1539 SV *val = hv_iterval(ohv,entry);
1540 SV * const keysv = HeSVKEY(entry);
1541 val = SvIMMORTAL(val) ? val : newSVsv(val);
1543 (void)hv_store_ent(hv, keysv, val, 0);
1545 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1546 HeHASH(entry), HeKFLAGS(entry));
1548 HvRITER_set(ohv, riter);
1549 HvEITER_set(ohv, eiter);
1556 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1558 A specialised version of L</newHVhv> for copying C<%^H>. C<ohv> must be
1559 a pointer to a hash (which may have C<%^H> magic, but should be generally
1560 non-magical), or C<NULL> (interpreted as an empty hash). The content
1561 of C<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1562 added to it. A pointer to the new hash is returned.
1568 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1570 HV * const hv = newHV();
1573 STRLEN hv_max = HvMAX(ohv);
1574 STRLEN hv_keys = HvTOTALKEYS(ohv);
1576 const I32 riter = HvRITER_get(ohv);
1577 HE * const eiter = HvEITER_get(ohv);
1582 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1585 while ((entry = hv_iternext_flags(ohv, 0))) {
1586 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1587 SV *heksv = HeSVKEY(entry);
1588 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1589 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1590 (char *)heksv, HEf_SVKEY);
1591 if (heksv == HeSVKEY(entry))
1592 (void)hv_store_ent(hv, heksv, sv, 0);
1594 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1595 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1596 SvREFCNT_dec_NN(heksv);
1599 HvRITER_set(ohv, riter);
1600 HvEITER_set(ohv, eiter);
1602 SvREFCNT_inc_simple_void_NN(hv);
1605 hv_magic(hv, NULL, PERL_MAGIC_hints);
1608 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1610 /* like hv_free_ent, but returns the SV rather than freeing it */
1612 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1616 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1619 if (HeKLEN(entry) == HEf_SVKEY) {
1620 SvREFCNT_dec(HeKEY_sv(entry));
1621 Safefree(HeKEY_hek(entry));
1623 else if (HvSHAREKEYS(hv))
1624 unshare_hek(HeKEY_hek(entry));
1626 Safefree(HeKEY_hek(entry));
1633 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1637 PERL_ARGS_ASSERT_HV_FREE_ENT;
1641 val = hv_free_ent_ret(hv, entry);
1647 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1649 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1653 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1654 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1655 if (HeKLEN(entry) == HEf_SVKEY) {
1656 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1658 hv_free_ent(hv, entry);
1662 =for apidoc hv_clear
1664 Frees the all the elements of a hash, leaving it empty.
1665 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1667 See L</av_clear> for a note about the hash possibly being invalid on
1674 Perl_hv_clear(pTHX_ HV *hv)
1681 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1683 xhv = (XPVHV*)SvANY(hv);
1686 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1687 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1688 /* restricted hash: convert all keys to placeholders */
1690 for (i = 0; i <= xhv->xhv_max; i++) {
1691 HE *entry = (HvARRAY(hv))[i];
1692 for (; entry; entry = HeNEXT(entry)) {
1693 /* not already placeholder */
1694 if (HeVAL(entry) != &PL_sv_placeholder) {
1696 if (SvREADONLY(HeVAL(entry))) {
1697 SV* const keysv = hv_iterkeysv(entry);
1698 Perl_croak_nocontext(
1699 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1702 SvREFCNT_dec_NN(HeVAL(entry));
1704 HeVAL(entry) = &PL_sv_placeholder;
1705 HvPLACEHOLDERS(hv)++;
1712 HvPLACEHOLDERS_set(hv, 0);
1715 mg_clear(MUTABLE_SV(hv));
1717 HvHASKFLAGS_off(hv);
1721 mro_isa_changed_in(hv);
1722 HvEITER_set(hv, NULL);
1728 =for apidoc hv_clear_placeholders
1730 Clears any placeholders from a hash. If a restricted hash has any of its keys
1731 marked as readonly and the key is subsequently deleted, the key is not actually
1732 deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags
1733 it so it will be ignored by future operations such as iterating over the hash,
1734 but will still allow the hash to have a value reassigned to the key at some
1735 future point. This function clears any such placeholder keys from the hash.
1736 See C<L<Hash::Util::lock_keys()|Hash::Util/lock_keys>> for an example of its
1743 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1745 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1747 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1750 clear_placeholders(hv, items);
1754 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1759 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1766 /* Loop down the linked list heads */
1767 HE **oentry = &(HvARRAY(hv))[i];
1770 while ((entry = *oentry)) {
1771 if (HeVAL(entry) == &PL_sv_placeholder) {
1772 *oentry = HeNEXT(entry);
1773 if (entry == HvEITER_get(hv))
1776 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1777 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1778 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1779 hv_free_ent(hv, entry);
1784 I32 placeholders = HvPLACEHOLDERS_get(hv);
1785 HvTOTALKEYS(hv) -= (IV)placeholders;
1786 /* HvUSEDKEYS expanded */
1787 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1788 HvHASKFLAGS_off(hv);
1789 HvPLACEHOLDERS_set(hv, 0);
1793 oentry = &HeNEXT(entry);
1797 /* You can't get here, hence assertion should always fail. */
1798 assert (items == 0);
1799 NOT_REACHED; /* NOTREACHED */
1803 S_hfreeentries(pTHX_ HV *hv)
1806 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1809 PERL_ARGS_ASSERT_HFREEENTRIES;
1811 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1817 /* hfree_next_entry()
1818 * For use only by S_hfreeentries() and sv_clear().
1819 * Delete the next available HE from hv and return the associated SV.
1820 * Returns null on empty hash. Nevertheless null is not a reliable
1821 * indicator that the hash is empty, as the deleted entry may have a
1823 * indexp is a pointer to the current index into HvARRAY. The index should
1824 * initially be set to 0. hfree_next_entry() may update it. */
1827 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1829 struct xpvhv_aux *iter;
1833 STRLEN orig_index = *indexp;
1836 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1838 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1839 if ((entry = iter->xhv_eiter)) {
1840 /* the iterator may get resurrected after each
1841 * destructor call, so check each time */
1842 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1844 hv_free_ent(hv, entry);
1845 /* warning: at this point HvARRAY may have been
1846 * re-allocated, HvMAX changed etc */
1848 iter = HvAUX(hv); /* may have been realloced */
1849 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1850 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1851 #ifdef PERL_HASH_RANDOMIZE_KEYS
1852 iter->xhv_last_rand = iter->xhv_rand;
1855 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1856 will actually call HvFILL() on a hash under destruction, so it
1857 seems pointless attempting to track the number of keys remaining.
1858 But if they do, we want to reset it again. */
1859 if (iter->xhv_fill_lazy)
1860 iter->xhv_fill_lazy = 0;
1863 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1866 array = HvARRAY(hv);
1868 while ( ! ((entry = array[*indexp])) ) {
1869 if ((*indexp)++ >= HvMAX(hv))
1871 assert(*indexp != orig_index);
1873 array[*indexp] = HeNEXT(entry);
1874 ((XPVHV*) SvANY(hv))->xhv_keys--;
1876 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1877 && HeVAL(entry) && isGV(HeVAL(entry))
1878 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1881 const char * const key = HePV(entry,klen);
1882 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1883 || (klen == 1 && key[0] == ':')) {
1885 NULL, GvHV(HeVAL(entry)),
1886 (GV *)HeVAL(entry), 0
1890 return hv_free_ent_ret(hv, entry);
1895 =for apidoc hv_undef
1897 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1899 As well as freeing all the elements of the hash (like C<hv_clear()>), this
1900 also frees any auxiliary data and storage associated with the hash.
1902 See L</av_clear> for a note about the hash possibly being invalid on
1909 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1916 save = !!SvREFCNT(hv);
1917 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1918 xhv = (XPVHV*)SvANY(hv);
1920 /* The name must be deleted before the call to hfreeeeentries so that
1921 CVs are anonymised properly. But the effective name must be pre-
1922 served until after that call (and only deleted afterwards if the
1923 call originated from sv_clear). For stashes with one name that is
1924 both the canonical name and the effective name, hv_name_set has to
1925 allocate an array for storing the effective name. We can skip that
1926 during global destruction, as it does not matter where the CVs point
1927 if they will be freed anyway. */
1928 /* note that the code following prior to hfreeentries is duplicated
1929 * in sv_clear(), and changes here should be done there too */
1930 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1931 if (PL_stashcache) {
1932 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1933 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1934 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1936 hv_name_set(hv, NULL, 0, 0);
1940 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1944 struct mro_meta *meta;
1947 if (HvENAME_get(hv)) {
1948 if (PL_phase != PERL_PHASE_DESTRUCT)
1949 mro_isa_changed_in(hv);
1950 if (PL_stashcache) {
1951 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1952 HEKf"'\n", HEKfARG(HvENAME_HEK(hv))));
1953 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1957 /* If this call originated from sv_clear, then we must check for
1958 * effective names that need freeing, as well as the usual name. */
1960 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
1961 if (name && PL_stashcache) {
1962 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1963 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1964 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1966 hv_name_set(hv, NULL, 0, flags);
1968 if((meta = HvAUX(hv)->xhv_mro_meta)) {
1969 if (meta->mro_linear_all) {
1970 SvREFCNT_dec_NN(meta->mro_linear_all);
1971 /* mro_linear_current is just acting as a shortcut pointer,
1975 /* Only the current MRO is stored, so this owns the data.
1977 SvREFCNT_dec(meta->mro_linear_current);
1978 SvREFCNT_dec(meta->mro_nextmethod);
1979 SvREFCNT_dec(meta->isa);
1980 SvREFCNT_dec(meta->super);
1982 HvAUX(hv)->xhv_mro_meta = NULL;
1984 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
1985 SvFLAGS(hv) &= ~SVf_OOK;
1988 Safefree(HvARRAY(hv));
1989 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1992 /* if we're freeing the HV, the SvMAGIC field has been reused for
1993 * other purposes, and so there can't be any placeholder magic */
1995 HvPLACEHOLDERS_set(hv, 0);
1998 mg_clear(MUTABLE_SV(hv));
2005 Returns the number of hash buckets that
2006 happen to be in use. This function is
2007 wrapped by the macro C<HvFILL>.
2009 Previously this value was always stored in the HV structure, which created an
2010 overhead on every hash (and pretty much every object) for something that was
2011 rarely used. Now we calculate it on demand the first
2012 time that it is needed, and cache it if that calculation
2013 is going to be costly to repeat. The cached
2014 value is updated by insertions and deletions, but (currently) discarded if
2021 Perl_hv_fill(pTHX_ HV *const hv)
2024 HE **ents = HvARRAY(hv);
2025 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
2027 PERL_ARGS_ASSERT_HV_FILL;
2029 /* No keys implies no buckets used.
2030 One key can only possibly mean one bucket used. */
2031 if (HvTOTALKEYS(hv) < 2)
2032 return HvTOTALKEYS(hv);
2035 if (aux && aux->xhv_fill_lazy)
2036 return aux->xhv_fill_lazy;
2040 HE *const *const last = ents + HvMAX(hv);
2041 count = last + 1 - ents;
2046 } while (++ents <= last);
2050 if (aux->xhv_fill_lazy)
2051 assert(aux->xhv_fill_lazy == count);
2053 aux->xhv_fill_lazy = count;
2054 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
2055 aux = hv_auxinit(hv);
2056 aux->xhv_fill_lazy = count;
2061 /* hash a pointer to a U32 - Used in the hash traversal randomization
2062 * and bucket order randomization code
2064 * this code was derived from Sereal, which was derived from autobox.
2067 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2070 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2071 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2073 u = (~u) + (u << 18);
2081 * This is one of Bob Jenkins' hash functions for 32-bit integers
2082 * from: http://burtleburtle.net/bob/hash/integer.html
2084 u = (u + 0x7ed55d16) + (u << 12);
2085 u = (u ^ 0xc761c23c) ^ (u >> 19);
2086 u = (u + 0x165667b1) + (u << 5);
2087 u = (u + 0xd3a2646c) ^ (u << 9);
2088 u = (u + 0xfd7046c5) + (u << 3);
2089 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2094 static struct xpvhv_aux*
2095 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
2096 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
2097 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2098 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2099 #ifdef PERL_HASH_RANDOMIZE_KEYS
2100 iter->xhv_last_rand = iter->xhv_rand;
2102 iter->xhv_fill_lazy = 0;
2103 iter->xhv_name_u.xhvnameu_name = 0;
2104 iter->xhv_name_count = 0;
2105 iter->xhv_backreferences = 0;
2106 iter->xhv_mro_meta = NULL;
2107 iter->xhv_aux_flags = 0;
2112 static struct xpvhv_aux*
2113 S_hv_auxinit(pTHX_ HV *hv) {
2114 struct xpvhv_aux *iter;
2117 PERL_ARGS_ASSERT_HV_AUXINIT;
2121 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2122 + sizeof(struct xpvhv_aux), char);
2124 array = (char *) HvARRAY(hv);
2125 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2126 + sizeof(struct xpvhv_aux), char);
2128 HvARRAY(hv) = (HE**)array;
2131 #ifdef PERL_HASH_RANDOMIZE_KEYS
2132 if (PL_HASH_RAND_BITS_ENABLED) {
2133 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2134 if (PL_HASH_RAND_BITS_ENABLED == 1)
2135 PL_hash_rand_bits += ptr_hash((PTRV)array);
2136 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2138 iter->xhv_rand = (U32)PL_hash_rand_bits;
2144 return hv_auxinit_internal(iter);
2148 =for apidoc hv_iterinit
2150 Prepares a starting point to traverse a hash table. Returns the number of
2151 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
2152 currently only meaningful for hashes without tie magic.
2154 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2155 hash buckets that happen to be in use. If you still need that esoteric
2156 value, you can get it through the macro C<HvFILL(hv)>.
2163 Perl_hv_iterinit(pTHX_ HV *hv)
2165 PERL_ARGS_ASSERT_HV_ITERINIT;
2168 struct xpvhv_aux * iter = HvAUX(hv);
2169 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2170 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2172 hv_free_ent(hv, entry);
2174 iter = HvAUX(hv); /* may have been reallocated */
2175 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2176 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2177 #ifdef PERL_HASH_RANDOMIZE_KEYS
2178 iter->xhv_last_rand = iter->xhv_rand;
2184 /* used to be xhv->xhv_fill before 5.004_65 */
2185 return HvTOTALKEYS(hv);
2189 Perl_hv_riter_p(pTHX_ HV *hv) {
2190 struct xpvhv_aux *iter;
2192 PERL_ARGS_ASSERT_HV_RITER_P;
2194 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2195 return &(iter->xhv_riter);
2199 Perl_hv_eiter_p(pTHX_ HV *hv) {
2200 struct xpvhv_aux *iter;
2202 PERL_ARGS_ASSERT_HV_EITER_P;
2204 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2205 return &(iter->xhv_eiter);
2209 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2210 struct xpvhv_aux *iter;
2212 PERL_ARGS_ASSERT_HV_RITER_SET;
2220 iter = hv_auxinit(hv);
2222 iter->xhv_riter = riter;
2226 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2227 struct xpvhv_aux *iter;
2229 PERL_ARGS_ASSERT_HV_RAND_SET;
2231 #ifdef PERL_HASH_RANDOMIZE_KEYS
2235 iter = hv_auxinit(hv);
2237 iter->xhv_rand = new_xhv_rand;
2239 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2244 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2245 struct xpvhv_aux *iter;
2247 PERL_ARGS_ASSERT_HV_EITER_SET;
2252 /* 0 is the default so don't go malloc()ing a new structure just to
2257 iter = hv_auxinit(hv);
2259 iter->xhv_eiter = eiter;
2263 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2266 struct xpvhv_aux *iter;
2270 PERL_ARGS_ASSERT_HV_NAME_SET;
2273 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2277 if (iter->xhv_name_u.xhvnameu_name) {
2278 if(iter->xhv_name_count) {
2279 if(flags & HV_NAME_SETALL) {
2280 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2281 HEK **hekp = name + (
2282 iter->xhv_name_count < 0
2283 ? -iter->xhv_name_count
2284 : iter->xhv_name_count
2286 while(hekp-- > name+1)
2287 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2288 /* The first elem may be null. */
2289 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2291 iter = HvAUX(hv); /* may been realloced */
2292 spot = &iter->xhv_name_u.xhvnameu_name;
2293 iter->xhv_name_count = 0;
2296 if(iter->xhv_name_count > 0) {
2297 /* shift some things over */
2299 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2301 spot = iter->xhv_name_u.xhvnameu_names;
2302 spot[iter->xhv_name_count] = spot[1];
2304 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2306 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2307 unshare_hek_or_pvn(*spot, 0, 0, 0);
2311 else if (flags & HV_NAME_SETALL) {
2312 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2313 iter = HvAUX(hv); /* may been realloced */
2314 spot = &iter->xhv_name_u.xhvnameu_name;
2317 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2318 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2319 iter->xhv_name_count = -2;
2320 spot = iter->xhv_name_u.xhvnameu_names;
2321 spot[1] = existing_name;
2324 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2329 iter = hv_auxinit(hv);
2330 spot = &iter->xhv_name_u.xhvnameu_name;
2332 PERL_HASH(hash, name, len);
2333 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2337 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2342 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2343 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2344 if (flags & SVf_UTF8)
2345 return (bytes_cmp_utf8(
2346 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2347 (const U8*)pv, pvlen) == 0);
2349 return (bytes_cmp_utf8(
2350 (const U8*)pv, pvlen,
2351 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2354 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2355 || memEQ(HEK_KEY(hek), pv, pvlen));
2359 =for apidoc hv_ename_add
2361 Adds a name to a stash's internal list of effective names. See
2362 C<L</hv_ename_delete>>.
2364 This is called when a stash is assigned to a new location in the symbol
2371 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2374 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2377 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2380 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2382 PERL_HASH(hash, name, len);
2384 if (aux->xhv_name_count) {
2385 I32 count = aux->xhv_name_count;
2386 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2387 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2388 while (hekp-- > xhv_name)
2392 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2393 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2394 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2396 if (hekp == xhv_name && count < 0)
2397 aux->xhv_name_count = -count;
2401 if (count < 0) aux->xhv_name_count--, count = -count;
2402 else aux->xhv_name_count++;
2403 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2404 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2407 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2410 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2411 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2412 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2415 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2416 aux->xhv_name_count = existing_name ? 2 : -2;
2417 *aux->xhv_name_u.xhvnameu_names = existing_name;
2418 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2423 =for apidoc hv_ename_delete
2425 Removes a name from a stash's internal list of effective names. If this is
2426 the name returned by C<HvENAME>, then another name in the list will take
2427 its place (C<HvENAME> will use it).
2429 This is called when a stash is deleted from the symbol table.
2435 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2437 struct xpvhv_aux *aux;
2439 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2442 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2444 if (!SvOOK(hv)) return;
2447 if (!aux->xhv_name_u.xhvnameu_name) return;
2449 if (aux->xhv_name_count) {
2450 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2451 I32 const count = aux->xhv_name_count;
2452 HEK **victim = namep + (count < 0 ? -count : count);
2453 while (victim-- > namep + 1)
2455 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2456 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2457 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2459 unshare_hek_or_pvn(*victim, 0, 0, 0);
2460 aux = HvAUX(hv); /* may been realloced */
2461 if (count < 0) ++aux->xhv_name_count;
2462 else --aux->xhv_name_count;
2464 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2466 ) { /* if there are none left */
2468 aux->xhv_name_u.xhvnameu_names = NULL;
2469 aux->xhv_name_count = 0;
2472 /* Move the last one back to fill the empty slot. It
2473 does not matter what order they are in. */
2474 *victim = *(namep + (count < 0 ? -count : count) - 1);
2479 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2480 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2481 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2483 aux->xhv_name_count = -count;
2487 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2488 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2489 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2490 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2492 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2493 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2494 *aux->xhv_name_u.xhvnameu_names = namehek;
2495 aux->xhv_name_count = -1;
2500 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2501 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2502 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2504 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2505 return &(iter->xhv_backreferences);
2510 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2513 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2518 av = HvAUX(hv)->xhv_backreferences;
2521 HvAUX(hv)->xhv_backreferences = 0;
2522 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2523 if (SvTYPE(av) == SVt_PVAV)
2524 SvREFCNT_dec_NN(av);
2529 hv_iternext is implemented as a macro in hv.h
2531 =for apidoc hv_iternext
2533 Returns entries from a hash iterator. See C<L</hv_iterinit>>.
2535 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2536 iterator currently points to, without losing your place or invalidating your
2537 iterator. Note that in this case the current entry is deleted from the hash
2538 with your iterator holding the last reference to it. Your iterator is flagged
2539 to free the entry on the next call to C<hv_iternext>, so you must not discard
2540 your iterator immediately else the entry will leak - call C<hv_iternext> to
2541 trigger the resource deallocation.
2543 =for apidoc hv_iternext_flags
2545 Returns entries from a hash iterator. See C<L</hv_iterinit>> and
2547 The C<flags> value will normally be zero; if C<HV_ITERNEXT_WANTPLACEHOLDERS> is
2548 set the placeholders keys (for restricted hashes) will be returned in addition
2549 to normal keys. By default placeholders are automatically skipped over.
2550 Currently a placeholder is implemented with a value that is
2551 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2552 restricted hashes may change, and the implementation currently is
2553 insufficiently abstracted for any change to be tidy.
2559 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2566 struct xpvhv_aux *iter;
2568 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2570 xhv = (XPVHV*)SvANY(hv);
2573 /* Too many things (well, pp_each at least) merrily assume that you can
2574 call hv_iternext without calling hv_iterinit, so we'll have to deal
2580 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2581 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2582 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2583 SV * const key = sv_newmortal();
2585 sv_setsv(key, HeSVKEY_force(entry));
2586 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2587 HeSVKEY_set(entry, NULL);
2593 /* one HE per MAGICAL hash */
2594 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2595 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2597 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2599 HeKEY_hek(entry) = hek;
2600 HeKLEN(entry) = HEf_SVKEY;
2602 magic_nextpack(MUTABLE_SV(hv),mg,key);
2604 /* force key to stay around until next time */
2605 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2606 return entry; /* beware, hent_val is not set */
2608 SvREFCNT_dec(HeVAL(entry));
2609 Safefree(HeKEY_hek(entry));
2611 iter = HvAUX(hv); /* may been realloced */
2612 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2617 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2618 if (!entry && SvRMAGICAL((const SV *)hv)
2619 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2622 /* The prime_env_iter() on VMS just loaded up new hash values
2623 * so the iteration count needs to be reset back to the beginning
2627 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2632 /* hv_iterinit now ensures this. */
2633 assert (HvARRAY(hv));
2635 /* At start of hash, entry is NULL. */
2638 entry = HeNEXT(entry);
2639 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2641 * Skip past any placeholders -- don't want to include them in
2644 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2645 entry = HeNEXT(entry);
2650 #ifdef PERL_HASH_RANDOMIZE_KEYS
2651 if (iter->xhv_last_rand != iter->xhv_rand) {
2652 if (iter->xhv_riter != -1) {
2653 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2654 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2658 iter = HvAUX(hv); /* may been realloced */
2659 iter->xhv_last_rand = iter->xhv_rand;
2663 /* Skip the entire loop if the hash is empty. */
2664 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2665 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2667 /* OK. Come to the end of the current list. Grab the next one. */
2669 iter->xhv_riter++; /* HvRITER(hv)++ */
2670 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2671 /* There is no next one. End of the hash. */
2672 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2673 #ifdef PERL_HASH_RANDOMIZE_KEYS
2674 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2678 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2680 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2681 /* If we have an entry, but it's a placeholder, don't count it.
2683 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2684 entry = HeNEXT(entry);
2686 /* Will loop again if this linked list starts NULL
2687 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2688 or if we run through it and find only placeholders. */
2692 iter->xhv_riter = -1;
2693 #ifdef PERL_HASH_RANDOMIZE_KEYS
2694 iter->xhv_last_rand = iter->xhv_rand;
2698 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2700 hv_free_ent(hv, oldentry);
2703 iter = HvAUX(hv); /* may been realloced */
2704 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2709 =for apidoc hv_iterkey
2711 Returns the key from the current position of the hash iterator. See
2718 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2720 PERL_ARGS_ASSERT_HV_ITERKEY;
2722 if (HeKLEN(entry) == HEf_SVKEY) {
2724 char * const p = SvPV(HeKEY_sv(entry), len);
2729 *retlen = HeKLEN(entry);
2730 return HeKEY(entry);
2734 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2736 =for apidoc hv_iterkeysv
2738 Returns the key as an C<SV*> from the current position of the hash
2739 iterator. The return value will always be a mortal copy of the key. Also
2740 see C<L</hv_iterinit>>.
2746 Perl_hv_iterkeysv(pTHX_ HE *entry)
2748 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2750 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2754 =for apidoc hv_iterval
2756 Returns the value from the current position of the hash iterator. See
2763 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2765 PERL_ARGS_ASSERT_HV_ITERVAL;
2767 if (SvRMAGICAL(hv)) {
2768 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2769 SV* const sv = sv_newmortal();
2770 if (HeKLEN(entry) == HEf_SVKEY)
2771 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2773 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2777 return HeVAL(entry);
2781 =for apidoc hv_iternextsv
2783 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2790 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2792 HE * const he = hv_iternext_flags(hv, 0);
2794 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2798 *key = hv_iterkey(he, retlen);
2799 return hv_iterval(hv, he);
2806 =for apidoc hv_magic
2808 Adds magic to a hash. See C<L</sv_magic>>.
2813 /* possibly free a shared string if no one has access to it
2814 * len and hash must both be valid for str.
2817 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2819 unshare_hek_or_pvn (NULL, str, len, hash);
2824 Perl_unshare_hek(pTHX_ HEK *hek)
2827 unshare_hek_or_pvn(hek, NULL, 0, 0);
2830 /* possibly free a shared string if no one has access to it
2831 hek if non-NULL takes priority over the other 3, else str, len and hash
2832 are used. If so, len and hash must both be valid for str.
2835 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2840 bool is_utf8 = FALSE;
2842 const char * const save = str;
2843 struct shared_he *he = NULL;
2846 /* Find the shared he which is just before us in memory. */
2847 he = (struct shared_he *)(((char *)hek)
2848 - STRUCT_OFFSET(struct shared_he,
2851 /* Assert that the caller passed us a genuine (or at least consistent)
2853 assert (he->shared_he_he.hent_hek == hek);
2855 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2856 --he->shared_he_he.he_valu.hent_refcount;
2860 hash = HEK_HASH(hek);
2861 } else if (len < 0) {
2862 STRLEN tmplen = -len;
2864 /* See the note in hv_fetch(). --jhi */
2865 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2868 k_flags = HVhek_UTF8;
2870 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2873 /* what follows was the moral equivalent of:
2874 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2876 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2878 xhv = (XPVHV*)SvANY(PL_strtab);
2879 /* assert(xhv_array != 0) */
2880 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2882 const HE *const he_he = &(he->shared_he_he);
2883 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2888 const int flags_masked = k_flags & HVhek_MASK;
2889 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2890 if (HeHASH(entry) != hash) /* strings can't be equal */
2892 if (HeKLEN(entry) != len)
2894 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2896 if (HeKFLAGS(entry) != flags_masked)
2903 if (--entry->he_valu.hent_refcount == 0) {
2904 *oentry = HeNEXT(entry);
2906 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2911 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2912 "Attempt to free nonexistent shared string '%s'%s"
2914 hek ? HEK_KEY(hek) : str,
2915 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2916 if (k_flags & HVhek_FREEKEY)
2920 /* get a (constant) string ptr from the global string table
2921 * string will get added if it is not already there.
2922 * len and hash must both be valid for str.
2925 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2927 bool is_utf8 = FALSE;
2929 const char * const save = str;
2931 PERL_ARGS_ASSERT_SHARE_HEK;
2934 STRLEN tmplen = -len;
2936 /* See the note in hv_fetch(). --jhi */
2937 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2939 /* If we were able to downgrade here, then than means that we were passed
2940 in a key which only had chars 0-255, but was utf8 encoded. */
2943 /* If we found we were able to downgrade the string to bytes, then
2944 we should flag that it needs upgrading on keys or each. Also flag
2945 that we need share_hek_flags to free the string. */
2948 PERL_HASH(hash, str, len);
2949 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2953 return share_hek_flags (str, len, hash, flags);
2957 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2960 const int flags_masked = flags & HVhek_MASK;
2961 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2962 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2964 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2966 /* what follows is the moral equivalent of:
2968 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2969 hv_store(PL_strtab, str, len, NULL, hash);
2971 Can't rehash the shared string table, so not sure if it's worth
2972 counting the number of entries in the linked list
2975 /* assert(xhv_array != 0) */
2976 entry = (HvARRAY(PL_strtab))[hindex];
2977 for (;entry; entry = HeNEXT(entry)) {
2978 if (HeHASH(entry) != hash) /* strings can't be equal */
2980 if (HeKLEN(entry) != len)
2982 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2984 if (HeKFLAGS(entry) != flags_masked)
2990 /* What used to be head of the list.
2991 If this is NULL, then we're the first entry for this slot, which
2992 means we need to increate fill. */
2993 struct shared_he *new_entry;
2996 HE **const head = &HvARRAY(PL_strtab)[hindex];
2997 HE *const next = *head;
2999 /* We don't actually store a HE from the arena and a regular HEK.
3000 Instead we allocate one chunk of memory big enough for both,
3001 and put the HEK straight after the HE. This way we can find the
3002 HE directly from the HEK.
3005 Newx(k, STRUCT_OFFSET(struct shared_he,
3006 shared_he_hek.hek_key[0]) + len + 2, char);
3007 new_entry = (struct shared_he *)k;
3008 entry = &(new_entry->shared_he_he);
3009 hek = &(new_entry->shared_he_hek);
3011 Copy(str, HEK_KEY(hek), len, char);
3012 HEK_KEY(hek)[len] = 0;
3014 HEK_HASH(hek) = hash;
3015 HEK_FLAGS(hek) = (unsigned char)flags_masked;
3017 /* Still "point" to the HEK, so that other code need not know what
3019 HeKEY_hek(entry) = hek;
3020 entry->he_valu.hent_refcount = 0;
3021 HeNEXT(entry) = next;
3024 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
3025 if (!next) { /* initial entry? */
3026 } else if ( DO_HSPLIT(xhv) ) {
3027 const STRLEN oldsize = xhv->xhv_max + 1;
3028 hsplit(PL_strtab, oldsize, oldsize * 2);
3032 ++entry->he_valu.hent_refcount;
3034 if (flags & HVhek_FREEKEY)
3037 return HeKEY_hek(entry);
3041 Perl_hv_placeholders_p(pTHX_ HV *hv)
3043 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3045 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
3048 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
3051 Perl_die(aTHX_ "panic: hv_placeholders_p");
3054 return &(mg->mg_len);
3059 Perl_hv_placeholders_get(pTHX_ const HV *hv)
3061 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3063 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
3064 PERL_UNUSED_CONTEXT;
3066 return mg ? mg->mg_len : 0;
3070 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3072 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3074 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3079 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3080 Perl_die(aTHX_ "panic: hv_placeholders_set");
3082 /* else we don't need to add magic to record 0 placeholders. */
3086 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3091 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3093 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3098 value = &PL_sv_placeholder;
3101 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3104 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3107 case HVrhek_PV_UTF8:
3108 /* Create a string SV that directly points to the bytes in our
3110 value = newSV_type(SVt_PV);
3111 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3112 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3113 /* This stops anything trying to free it */
3114 SvLEN_set(value, 0);
3116 SvREADONLY_on(value);
3117 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3121 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
3122 (UV)he->refcounted_he_data[0]);
3128 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
3130 Generates and returns a C<HV *> representing the content of a
3131 C<refcounted_he> chain.
3132 C<flags> is currently unused and must be zero.
3137 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3141 U32 placeholders, max;
3144 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3147 /* We could chase the chain once to get an idea of the number of keys,
3148 and call ksplit. But for now we'll make a potentially inefficient
3149 hash with only 8 entries in its array. */
3154 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3155 HvARRAY(hv) = (HE**)array;
3161 U32 hash = chain->refcounted_he_hash;
3163 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3165 HE **oentry = &((HvARRAY(hv))[hash & max]);
3166 HE *entry = *oentry;
3169 for (; entry; entry = HeNEXT(entry)) {
3170 if (HeHASH(entry) == hash) {
3171 /* We might have a duplicate key here. If so, entry is older
3172 than the key we've already put in the hash, so if they are
3173 the same, skip adding entry. */
3175 const STRLEN klen = HeKLEN(entry);
3176 const char *const key = HeKEY(entry);
3177 if (klen == chain->refcounted_he_keylen
3178 && (!!HeKUTF8(entry)
3179 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3180 && memEQ(key, REF_HE_KEY(chain), klen))
3183 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3185 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3186 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3187 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3198 = share_hek_flags(REF_HE_KEY(chain),
3199 chain->refcounted_he_keylen,
3200 chain->refcounted_he_hash,
3201 (chain->refcounted_he_data[0]
3202 & (HVhek_UTF8|HVhek_WASUTF8)));
3204 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3206 value = refcounted_he_value(chain);
3207 if (value == &PL_sv_placeholder)
3209 HeVAL(entry) = value;
3211 /* Link it into the chain. */
3212 HeNEXT(entry) = *oentry;
3218 chain = chain->refcounted_he_next;
3222 clear_placeholders(hv, placeholders);
3223 HvTOTALKEYS(hv) -= placeholders;
3226 /* We could check in the loop to see if we encounter any keys with key
3227 flags, but it's probably not worth it, as this per-hash flag is only
3228 really meant as an optimisation for things like Storable. */
3230 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3236 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3238 Search along a C<refcounted_he> chain for an entry with the key specified
3239 by C<keypv> and C<keylen>. If C<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3240 bit set, the key octets are interpreted as UTF-8, otherwise they
3241 are interpreted as Latin-1. C<hash> is a precomputed hash of the key
3242 string, or zero if it has not been precomputed. Returns a mortal scalar
3243 representing the value associated with the key, or C<&PL_sv_placeholder>
3244 if there is no value associated with the key.
3250 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3251 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3255 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3257 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3258 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3262 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3263 /* For searching purposes, canonicalise to Latin-1 where possible. */
3264 const char *keyend = keypv + keylen, *p;
3265 STRLEN nonascii_count = 0;
3266 for (p = keypv; p != keyend; p++) {
3267 if (! UTF8_IS_INVARIANT(*p)) {
3268 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3269 goto canonicalised_key;
3275 if (nonascii_count) {
3277 const char *p = keypv, *keyend = keypv + keylen;
3278 keylen -= nonascii_count;
3279 Newx(q, keylen, char);
3282 for (; p != keyend; p++, q++) {
3284 if (UTF8_IS_INVARIANT(c)) {
3289 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3293 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3294 canonicalised_key: ;
3296 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3298 PERL_HASH(hash, keypv, keylen);
3300 for (; chain; chain = chain->refcounted_he_next) {
3303 hash == chain->refcounted_he_hash &&
3304 keylen == chain->refcounted_he_keylen &&
3305 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3306 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3308 hash == HEK_HASH(chain->refcounted_he_hek) &&
3309 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3310 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3311 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3314 if (flags & REFCOUNTED_HE_EXISTS)
3315 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3317 ? NULL : &PL_sv_yes;
3318 return sv_2mortal(refcounted_he_value(chain));
3322 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3326 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3328 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3329 instead of a string/length pair.
3335 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3336 const char *key, U32 hash, U32 flags)
3338 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3339 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3343 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3345 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3352 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3353 SV *key, U32 hash, U32 flags)
3357 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3358 if (flags & REFCOUNTED_HE_KEY_UTF8)
3359 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3361 keypv = SvPV_const(key, keylen);
3363 flags |= REFCOUNTED_HE_KEY_UTF8;
3364 if (!hash && SvIsCOW_shared_hash(key))
3365 hash = SvSHARED_HASH(key);
3366 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3370 =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
3372 Creates a new C<refcounted_he>. This consists of a single key/value
3373 pair and a reference to an existing C<refcounted_he> chain (which may
3374 be empty), and thus forms a longer chain. When using the longer chain,
3375 the new key/value pair takes precedence over any entry for the same key
3376 further along the chain.
3378 The new key is specified by C<keypv> and C<keylen>. If C<flags> has
3379 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3380 as UTF-8, otherwise they are interpreted as Latin-1. C<hash> is
3381 a precomputed hash of the key string, or zero if it has not been
3384 C<value> is the scalar value to store for this key. C<value> is copied
3385 by this function, which thus does not take ownership of any reference
3386 to it, and later changes to the scalar will not be reflected in the
3387 value visible in the C<refcounted_he>. Complex types of scalar will not
3388 be stored with referential integrity, but will be coerced to strings.
3389 C<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3390 value is to be associated with the key; this, as with any non-null value,
3391 takes precedence over the existence of a value for the key further along
3394 C<parent> points to the rest of the C<refcounted_he> chain to be
3395 attached to the new C<refcounted_he>. This function takes ownership
3396 of one reference to C<parent>, and returns one reference to the new
3402 struct refcounted_he *
3403 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3404 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3407 STRLEN value_len = 0;
3408 const char *value_p = NULL;
3412 STRLEN key_offset = 1;
3413 struct refcounted_he *he;
3414 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3416 if (!value || value == &PL_sv_placeholder) {
3417 value_type = HVrhek_delete;
3418 } else if (SvPOK(value)) {
3419 value_type = HVrhek_PV;
3420 } else if (SvIOK(value)) {
3421 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3422 } else if (!SvOK(value)) {
3423 value_type = HVrhek_undef;
3425 value_type = HVrhek_PV;
3427 is_pv = value_type == HVrhek_PV;
3429 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3430 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3431 value_p = SvPV_const(value, value_len);
3433 value_type = HVrhek_PV_UTF8;
3434 key_offset = value_len + 2;
3436 hekflags = value_type;
3438 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3439 /* Canonicalise to Latin-1 where possible. */
3440 const char *keyend = keypv + keylen, *p;
3441 STRLEN nonascii_count = 0;
3442 for (p = keypv; p != keyend; p++) {
3443 if (! UTF8_IS_INVARIANT(*p)) {
3444 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3445 goto canonicalised_key;
3451 if (nonascii_count) {
3453 const char *p = keypv, *keyend = keypv + keylen;
3454 keylen -= nonascii_count;
3455 Newx(q, keylen, char);
3458 for (; p != keyend; p++, q++) {
3460 if (UTF8_IS_INVARIANT(c)) {
3465 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3469 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3470 canonicalised_key: ;
3472 if (flags & REFCOUNTED_HE_KEY_UTF8)
3473 hekflags |= HVhek_UTF8;
3475 PERL_HASH(hash, keypv, keylen);
3478 he = (struct refcounted_he*)
3479 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3483 he = (struct refcounted_he*)
3484 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3488 he->refcounted_he_next = parent;
3491 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3492 he->refcounted_he_val.refcounted_he_u_len = value_len;
3493 } else if (value_type == HVrhek_IV) {
3494 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3495 } else if (value_type == HVrhek_UV) {
3496 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3500 he->refcounted_he_hash = hash;
3501 he->refcounted_he_keylen = keylen;
3502 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3504 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3507 he->refcounted_he_data[0] = hekflags;
3508 he->refcounted_he_refcnt = 1;
3514 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3516 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3517 of a string/length pair.
3522 struct refcounted_he *
3523 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3524 const char *key, U32 hash, SV *value, U32 flags)
3526 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3527 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3531 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3533 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3539 struct refcounted_he *
3540 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3541 SV *key, U32 hash, SV *value, U32 flags)
3545 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3546 if (flags & REFCOUNTED_HE_KEY_UTF8)
3547 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3549 keypv = SvPV_const(key, keylen);
3551 flags |= REFCOUNTED_HE_KEY_UTF8;
3552 if (!hash && SvIsCOW_shared_hash(key))
3553 hash = SvSHARED_HASH(key);
3554 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3558 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3560 Decrements the reference count of a C<refcounted_he> by one. If the
3561 reference count reaches zero the structure's memory is freed, which
3562 (recursively) causes a reduction of its parent C<refcounted_he>'s
3563 reference count. It is safe to pass a null pointer to this function:
3564 no action occurs in this case.
3570 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3574 PERL_UNUSED_CONTEXT;
3577 struct refcounted_he *copy;
3581 new_count = --he->refcounted_he_refcnt;
3582 HINTS_REFCNT_UNLOCK;
3588 #ifndef USE_ITHREADS
3589 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3592 he = he->refcounted_he_next;
3593 PerlMemShared_free(copy);
3598 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3600 Increment the reference count of a C<refcounted_he>. The pointer to the
3601 C<refcounted_he> is also returned. It is safe to pass a null pointer
3602 to this function: no action occurs and a null pointer is returned.
3607 struct refcounted_he *
3608 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3613 PERL_UNUSED_CONTEXT;
3616 he->refcounted_he_refcnt++;
3617 HINTS_REFCNT_UNLOCK;
3623 =for apidoc cop_fetch_label
3625 Returns the label attached to a cop.
3626 The flags pointer may be set to C<SVf_UTF8> or 0.
3631 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3634 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3635 struct refcounted_he *const chain = cop->cop_hints_hash;
3637 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3638 PERL_UNUSED_CONTEXT;
3643 if (chain->refcounted_he_keylen != 1)
3645 if (*REF_HE_KEY(chain) != ':')
3648 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3650 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3653 /* Stop anyone trying to really mess us up by adding their own value for
3655 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3656 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3660 *len = chain->refcounted_he_val.refcounted_he_u_len;
3662 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3663 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3665 return chain->refcounted_he_data + 1;
3669 =for apidoc cop_store_label
3671 Save a label into a C<cop_hints_hash>.
3672 You need to set flags to C<SVf_UTF8>
3679 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3683 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3685 if (flags & ~(SVf_UTF8))
3686 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3688 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3689 if (flags & SVf_UTF8)
3692 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3696 =for apidoc hv_assert
3698 Check that a hash is in an internally consistent state.
3706 Perl_hv_assert(pTHX_ HV *hv)
3711 int placeholders = 0;
3714 const I32 riter = HvRITER_get(hv);
3715 HE *eiter = HvEITER_get(hv);
3717 PERL_ARGS_ASSERT_HV_ASSERT;
3719 (void)hv_iterinit(hv);
3721 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3722 /* sanity check the values */
3723 if (HeVAL(entry) == &PL_sv_placeholder)
3727 /* sanity check the keys */
3728 if (HeSVKEY(entry)) {
3729 NOOP; /* Don't know what to check on SV keys. */
3730 } else if (HeKUTF8(entry)) {
3732 if (HeKWASUTF8(entry)) {
3733 PerlIO_printf(Perl_debug_log,
3734 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3735 (int) HeKLEN(entry), HeKEY(entry));
3738 } else if (HeKWASUTF8(entry))
3741 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3742 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3743 const int nhashkeys = HvUSEDKEYS(hv);
3744 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3746 if (nhashkeys != real) {
3747 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3750 if (nhashplaceholders != placeholders) {
3751 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3755 if (withflags && ! HvHASKFLAGS(hv)) {
3756 PerlIO_printf(Perl_debug_log,
3757 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3762 sv_dump(MUTABLE_SV(hv));
3764 HvRITER_set(hv, riter); /* Restore hash iterator state */
3765 HvEITER_set(hv, eiter);
3771 * ex: set ts=8 sts=4 sw=4 et: