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 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 NULL. Effectively
230 a successful 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, 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. hv_store is not implemented as a call to
235 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 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 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 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, 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 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. hv_store
260 is not implemented as a call to 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 hv_store in preference to 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 G_DISCARD then NULL will be returned.
977 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 G_DISCARD then NULL will be returned. NULL will also be
984 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))
1173 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1174 HeVAL(entry) = &PL_sv_placeholder;
1176 /* deletion of method from stash */
1177 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1179 mro_method_changed_in(hv);
1183 * If a restricted hash, rather than really deleting the entry, put
1184 * a placeholder there. This marks the key as being "approved", so
1185 * we can still access via not-really-existing key without raising
1189 /* We'll be saving this slot, so the number of allocated keys
1190 * doesn't go down, but the number placeholders goes up */
1191 HvPLACEHOLDERS(hv)++;
1193 *oentry = HeNEXT(entry);
1194 if(!*first_entry && SvOOK(hv)) {
1195 /* removed last entry, and aux struct present. */
1196 struct xpvhv_aux *const aux = HvAUX(hv);
1197 if (aux->xhv_fill_lazy)
1198 --aux->xhv_fill_lazy;
1200 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1203 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1204 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1205 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1206 hv_free_ent(hv, entry);
1208 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1209 if (xhv->xhv_keys == 0)
1210 HvHASKFLAGS_off(hv);
1213 if (d_flags & G_DISCARD) {
1218 if (mro_changes == 1) mro_isa_changed_in(hv);
1219 else if (mro_changes == 2)
1220 mro_package_moved(NULL, stash, gv, 1);
1226 if (SvREADONLY(hv)) {
1227 hv_notallowed(k_flags, key, klen,
1228 "Attempt to delete disallowed key '%"SVf"' from"
1229 " a restricted hash");
1232 if (k_flags & HVhek_FREEKEY)
1239 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1242 char *a = (char*) HvARRAY(hv);
1246 /* already have an HvAUX(hv) so we have to move it */
1248 /* no HvAUX() but array we are going to allocate is large enough
1249 * there is no point in saving the space for the iterator, and
1250 * speeds up later traversals. */
1251 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1254 PERL_ARGS_ASSERT_HSPLIT;
1257 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1258 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1264 #ifdef PERL_HASH_RANDOMIZE_KEYS
1265 /* the idea of this is that we create a "random" value by hashing the address of
1266 * the array, we then use the low bit to decide if we insert at the top, or insert
1267 * second from top. After each such insert we rotate the hashed value. So we can
1268 * use the same hashed value over and over, and in normal build environments use
1269 * very few ops to do so. ROTL32() should produce a single machine operation. */
1270 if (PL_HASH_RAND_BITS_ENABLED) {
1271 if (PL_HASH_RAND_BITS_ENABLED == 1)
1272 PL_hash_rand_bits += ptr_hash((PTRV)a);
1273 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1276 HvARRAY(hv) = (HE**) a;
1277 HvMAX(hv) = newsize - 1;
1278 /* before we zero the newly added memory, we
1279 * need to deal with the aux struct that may be there
1280 * or have been allocated by us*/
1282 struct xpvhv_aux *const dest
1283 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1285 /* alread have an aux, copy the old one in place. */
1286 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1287 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1288 #ifdef PERL_HASH_RANDOMIZE_KEYS
1289 dest->xhv_rand = (U32)PL_hash_rand_bits;
1291 /* For now, just reset the lazy fill counter.
1292 It would be possible to update the counter in the code below
1294 dest->xhv_fill_lazy = 0;
1296 /* no existing aux structure, but we allocated space for one
1297 * so initialize it properly. This unrolls hv_auxinit() a bit,
1298 * since we have to do the realloc anyway. */
1299 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1300 #ifdef PERL_HASH_RANDOMIZE_KEYS
1301 dest->xhv_rand = (U32)PL_hash_rand_bits;
1303 /* this is the "non realloc" part of the hv_auxinit() */
1304 (void)hv_auxinit_internal(dest);
1305 /* Turn on the OOK flag */
1309 /* now we can safely clear the second half */
1310 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1312 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1318 HE **oentry = aep + i;
1321 if (!entry) /* non-existent */
1324 U32 j = (HeHASH(entry) & newsize);
1326 *oentry = HeNEXT(entry);
1327 #ifdef PERL_HASH_RANDOMIZE_KEYS
1328 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1329 * insert to top, otherwise rotate the bucket rand 1 bit,
1330 * and use the new low bit to decide if we insert at top,
1331 * or next from top. IOW, we only rotate on a collision.*/
1332 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1333 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1334 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1335 if (PL_hash_rand_bits & 1) {
1336 HeNEXT(entry)= HeNEXT(aep[j]);
1337 HeNEXT(aep[j])= entry;
1339 /* Note, this is structured in such a way as the optimizer
1340 * should eliminate the duplicated code here and below without
1341 * us needing to explicitly use a goto. */
1342 HeNEXT(entry) = aep[j];
1348 /* see comment above about duplicated code */
1349 HeNEXT(entry) = aep[j];
1354 oentry = &HeNEXT(entry);
1358 } while (i++ < oldsize);
1362 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1364 XPVHV* xhv = (XPVHV*)SvANY(hv);
1365 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1369 PERL_ARGS_ASSERT_HV_KSPLIT;
1371 newsize = (I32) newmax; /* possible truncation here */
1372 if (newsize != newmax || newmax <= oldsize)
1374 while ((newsize & (1 + ~newsize)) != newsize) {
1375 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1377 if (newsize < newmax)
1379 if (newsize < newmax)
1380 return; /* overflow detection */
1382 a = (char *) HvARRAY(hv);
1384 hsplit(hv, oldsize, newsize);
1386 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1387 xhv->xhv_max = --newsize;
1388 HvARRAY(hv) = (HE **) a;
1392 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1393 * as tied hashes could play silly buggers and mess us around. We will
1394 * do the right thing during hv_store() afterwards, but still - Yves */
1395 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1396 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1397 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1398 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1400 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1401 hv_max = hv_max / 2; \
1403 HvMAX(hv) = hv_max; \
1408 Perl_newHVhv(pTHX_ HV *ohv)
1411 HV * const hv = newHV();
1414 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1416 hv_max = HvMAX(ohv);
1418 if (!SvMAGICAL((const SV *)ohv)) {
1419 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1421 const bool shared = !!HvSHAREKEYS(ohv);
1422 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1424 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1427 /* In each bucket... */
1428 for (i = 0; i <= hv_max; i++) {
1430 HE *oent = oents[i];
1437 /* Copy the linked list of entries. */
1438 for (; oent; oent = HeNEXT(oent)) {
1439 const U32 hash = HeHASH(oent);
1440 const char * const key = HeKEY(oent);
1441 const STRLEN len = HeKLEN(oent);
1442 const int flags = HeKFLAGS(oent);
1443 HE * const ent = new_HE();
1444 SV *const val = HeVAL(oent);
1446 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1448 = shared ? share_hek_flags(key, len, hash, flags)
1449 : save_hek_flags(key, len, hash, flags);
1460 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1464 /* Iterate over ohv, copying keys and values one at a time. */
1466 const I32 riter = HvRITER_get(ohv);
1467 HE * const eiter = HvEITER_get(ohv);
1468 STRLEN hv_keys = HvTOTALKEYS(ohv);
1470 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1473 while ((entry = hv_iternext_flags(ohv, 0))) {
1474 SV *val = hv_iterval(ohv,entry);
1475 SV * const keysv = HeSVKEY(entry);
1476 val = SvIMMORTAL(val) ? val : newSVsv(val);
1478 (void)hv_store_ent(hv, keysv, val, 0);
1480 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1481 HeHASH(entry), HeKFLAGS(entry));
1483 HvRITER_set(ohv, riter);
1484 HvEITER_set(ohv, eiter);
1491 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1493 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1494 a pointer to a hash (which may have C<%^H> magic, but should be generally
1495 non-magical), or C<NULL> (interpreted as an empty hash). The content
1496 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1497 added to it. A pointer to the new hash is returned.
1503 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1505 HV * const hv = newHV();
1508 STRLEN hv_max = HvMAX(ohv);
1509 STRLEN hv_keys = HvTOTALKEYS(ohv);
1511 const I32 riter = HvRITER_get(ohv);
1512 HE * const eiter = HvEITER_get(ohv);
1517 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1520 while ((entry = hv_iternext_flags(ohv, 0))) {
1521 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1522 SV *heksv = HeSVKEY(entry);
1523 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1524 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1525 (char *)heksv, HEf_SVKEY);
1526 if (heksv == HeSVKEY(entry))
1527 (void)hv_store_ent(hv, heksv, sv, 0);
1529 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1530 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1531 SvREFCNT_dec_NN(heksv);
1534 HvRITER_set(ohv, riter);
1535 HvEITER_set(ohv, eiter);
1537 SvREFCNT_inc_simple_void_NN(hv);
1540 hv_magic(hv, NULL, PERL_MAGIC_hints);
1543 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1545 /* like hv_free_ent, but returns the SV rather than freeing it */
1547 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1551 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1554 if (HeKLEN(entry) == HEf_SVKEY) {
1555 SvREFCNT_dec(HeKEY_sv(entry));
1556 Safefree(HeKEY_hek(entry));
1558 else if (HvSHAREKEYS(hv))
1559 unshare_hek(HeKEY_hek(entry));
1561 Safefree(HeKEY_hek(entry));
1568 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1572 PERL_ARGS_ASSERT_HV_FREE_ENT;
1576 val = hv_free_ent_ret(hv, entry);
1582 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1584 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1588 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1589 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1590 if (HeKLEN(entry) == HEf_SVKEY) {
1591 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1593 hv_free_ent(hv, entry);
1597 =for apidoc hv_clear
1599 Frees the all the elements of a hash, leaving it empty.
1600 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1602 If any destructors are triggered as a result, the hv itself may
1609 Perl_hv_clear(pTHX_ HV *hv)
1616 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1618 xhv = (XPVHV*)SvANY(hv);
1621 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1622 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1623 /* restricted hash: convert all keys to placeholders */
1625 for (i = 0; i <= xhv->xhv_max; i++) {
1626 HE *entry = (HvARRAY(hv))[i];
1627 for (; entry; entry = HeNEXT(entry)) {
1628 /* not already placeholder */
1629 if (HeVAL(entry) != &PL_sv_placeholder) {
1631 if (SvREADONLY(HeVAL(entry))) {
1632 SV* const keysv = hv_iterkeysv(entry);
1633 Perl_croak_nocontext(
1634 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1637 SvREFCNT_dec_NN(HeVAL(entry));
1639 HeVAL(entry) = &PL_sv_placeholder;
1640 HvPLACEHOLDERS(hv)++;
1647 HvPLACEHOLDERS_set(hv, 0);
1650 mg_clear(MUTABLE_SV(hv));
1652 HvHASKFLAGS_off(hv);
1656 mro_isa_changed_in(hv);
1657 HvEITER_set(hv, NULL);
1663 =for apidoc hv_clear_placeholders
1665 Clears any placeholders from a hash. If a restricted hash has any of its keys
1666 marked as readonly and the key is subsequently deleted, the key is not actually
1667 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1668 it so it will be ignored by future operations such as iterating over the hash,
1669 but will still allow the hash to have a value reassigned to the key at some
1670 future point. This function clears any such placeholder keys from the hash.
1671 See Hash::Util::lock_keys() for an example of its use.
1677 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1679 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1681 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1684 clear_placeholders(hv, items);
1688 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1693 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1700 /* Loop down the linked list heads */
1701 HE **oentry = &(HvARRAY(hv))[i];
1704 while ((entry = *oentry)) {
1705 if (HeVAL(entry) == &PL_sv_placeholder) {
1706 *oentry = HeNEXT(entry);
1707 if (entry == HvEITER_get(hv))
1710 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1711 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1712 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1713 hv_free_ent(hv, entry);
1718 I32 placeholders = HvPLACEHOLDERS_get(hv);
1719 HvTOTALKEYS(hv) -= (IV)placeholders;
1720 /* HvUSEDKEYS expanded */
1721 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1722 HvHASKFLAGS_off(hv);
1723 HvPLACEHOLDERS_set(hv, 0);
1727 oentry = &HeNEXT(entry);
1731 /* You can't get here, hence assertion should always fail. */
1732 assert (items == 0);
1733 NOT_REACHED; /* NOTREACHED */
1737 S_hfreeentries(pTHX_ HV *hv)
1740 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1743 PERL_ARGS_ASSERT_HFREEENTRIES;
1745 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1751 /* hfree_next_entry()
1752 * For use only by S_hfreeentries() and sv_clear().
1753 * Delete the next available HE from hv and return the associated SV.
1754 * Returns null on empty hash. Nevertheless null is not a reliable
1755 * indicator that the hash is empty, as the deleted entry may have a
1757 * indexp is a pointer to the current index into HvARRAY. The index should
1758 * initially be set to 0. hfree_next_entry() may update it. */
1761 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1763 struct xpvhv_aux *iter;
1767 STRLEN orig_index = *indexp;
1770 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1772 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1773 if ((entry = iter->xhv_eiter)) {
1774 /* the iterator may get resurrected after each
1775 * destructor call, so check each time */
1776 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1778 hv_free_ent(hv, entry);
1779 /* warning: at this point HvARRAY may have been
1780 * re-allocated, HvMAX changed etc */
1782 iter = HvAUX(hv); /* may have been realloced */
1783 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1784 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1785 #ifdef PERL_HASH_RANDOMIZE_KEYS
1786 iter->xhv_last_rand = iter->xhv_rand;
1789 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1790 will actually call HvFILL() on a hash under destruction, so it
1791 seems pointless attempting to track the number of keys remaining.
1792 But if they do, we want to reset it again. */
1793 if (iter->xhv_fill_lazy)
1794 iter->xhv_fill_lazy = 0;
1797 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1800 array = HvARRAY(hv);
1802 while ( ! ((entry = array[*indexp])) ) {
1803 if ((*indexp)++ >= HvMAX(hv))
1805 assert(*indexp != orig_index);
1807 array[*indexp] = HeNEXT(entry);
1808 ((XPVHV*) SvANY(hv))->xhv_keys--;
1810 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1811 && HeVAL(entry) && isGV(HeVAL(entry))
1812 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1815 const char * const key = HePV(entry,klen);
1816 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1817 || (klen == 1 && key[0] == ':')) {
1819 NULL, GvHV(HeVAL(entry)),
1820 (GV *)HeVAL(entry), 0
1824 return hv_free_ent_ret(hv, entry);
1829 =for apidoc hv_undef
1831 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1833 As well as freeing all the elements of the hash (like hv_clear()), this
1834 also frees any auxiliary data and storage associated with the hash.
1836 If any destructors are triggered as a result, the hv itself may
1839 See also L</hv_clear>.
1845 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1852 save = !!SvREFCNT(hv);
1853 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1854 xhv = (XPVHV*)SvANY(hv);
1856 /* The name must be deleted before the call to hfreeeeentries so that
1857 CVs are anonymised properly. But the effective name must be pre-
1858 served until after that call (and only deleted afterwards if the
1859 call originated from sv_clear). For stashes with one name that is
1860 both the canonical name and the effective name, hv_name_set has to
1861 allocate an array for storing the effective name. We can skip that
1862 during global destruction, as it does not matter where the CVs point
1863 if they will be freed anyway. */
1864 /* note that the code following prior to hfreeentries is duplicated
1865 * in sv_clear(), and changes here should be done there too */
1866 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1867 if (PL_stashcache) {
1868 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1869 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1870 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1872 hv_name_set(hv, NULL, 0, 0);
1876 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1880 struct mro_meta *meta;
1883 if (HvENAME_get(hv)) {
1884 if (PL_phase != PERL_PHASE_DESTRUCT)
1885 mro_isa_changed_in(hv);
1886 if (PL_stashcache) {
1887 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1888 HEKf"'\n", HEKfARG(HvENAME_HEK(hv))));
1889 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1893 /* If this call originated from sv_clear, then we must check for
1894 * effective names that need freeing, as well as the usual name. */
1896 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
1897 if (name && PL_stashcache) {
1898 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1899 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1900 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1902 hv_name_set(hv, NULL, 0, flags);
1904 if((meta = HvAUX(hv)->xhv_mro_meta)) {
1905 if (meta->mro_linear_all) {
1906 SvREFCNT_dec_NN(meta->mro_linear_all);
1907 /* mro_linear_current is just acting as a shortcut pointer,
1911 /* Only the current MRO is stored, so this owns the data.
1913 SvREFCNT_dec(meta->mro_linear_current);
1914 SvREFCNT_dec(meta->mro_nextmethod);
1915 SvREFCNT_dec(meta->isa);
1916 SvREFCNT_dec(meta->super);
1918 HvAUX(hv)->xhv_mro_meta = NULL;
1920 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
1921 SvFLAGS(hv) &= ~SVf_OOK;
1924 Safefree(HvARRAY(hv));
1925 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1928 /* if we're freeing the HV, the SvMAGIC field has been reused for
1929 * other purposes, and so there can't be any placeholder magic */
1931 HvPLACEHOLDERS_set(hv, 0);
1934 mg_clear(MUTABLE_SV(hv));
1941 Returns the number of hash buckets that
1942 happen to be in use. This function is
1943 wrapped by the macro C<HvFILL>.
1945 Previously this value was always stored in the HV structure, which created an
1946 overhead on every hash (and pretty much every object) for something that was
1947 rarely used. Now we calculate it on demand the first
1948 time that it is needed, and cache it if that calculation
1949 is going to be costly to repeat. The cached
1950 value is updated by insertions and deletions, but (currently) discarded if
1957 Perl_hv_fill(pTHX_ HV *const hv)
1960 HE **ents = HvARRAY(hv);
1961 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1963 PERL_ARGS_ASSERT_HV_FILL;
1965 /* No keys implies no buckets used.
1966 One key can only possibly mean one bucket used. */
1967 if (HvTOTALKEYS(hv) < 2)
1968 return HvTOTALKEYS(hv);
1971 if (aux && aux->xhv_fill_lazy)
1972 return aux->xhv_fill_lazy;
1976 HE *const *const last = ents + HvMAX(hv);
1977 count = last + 1 - ents;
1982 } while (++ents <= last);
1986 if (aux->xhv_fill_lazy)
1987 assert(aux->xhv_fill_lazy == count);
1989 aux->xhv_fill_lazy = count;
1990 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1991 aux = hv_auxinit(hv);
1992 aux->xhv_fill_lazy = count;
1997 /* hash a pointer to a U32 - Used in the hash traversal randomization
1998 * and bucket order randomization code
2000 * this code was derived from Sereal, which was derived from autobox.
2003 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2006 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2007 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2009 u = (~u) + (u << 18);
2017 * This is one of Bob Jenkins' hash functions for 32-bit integers
2018 * from: http://burtleburtle.net/bob/hash/integer.html
2020 u = (u + 0x7ed55d16) + (u << 12);
2021 u = (u ^ 0xc761c23c) ^ (u >> 19);
2022 u = (u + 0x165667b1) + (u << 5);
2023 u = (u + 0xd3a2646c) ^ (u << 9);
2024 u = (u + 0xfd7046c5) + (u << 3);
2025 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2030 static struct xpvhv_aux*
2031 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
2032 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
2033 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2034 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2035 #ifdef PERL_HASH_RANDOMIZE_KEYS
2036 iter->xhv_last_rand = iter->xhv_rand;
2038 iter->xhv_fill_lazy = 0;
2039 iter->xhv_name_u.xhvnameu_name = 0;
2040 iter->xhv_name_count = 0;
2041 iter->xhv_backreferences = 0;
2042 iter->xhv_mro_meta = NULL;
2043 iter->xhv_aux_flags = 0;
2048 static struct xpvhv_aux*
2049 S_hv_auxinit(pTHX_ HV *hv) {
2050 struct xpvhv_aux *iter;
2053 PERL_ARGS_ASSERT_HV_AUXINIT;
2057 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2058 + sizeof(struct xpvhv_aux), char);
2060 array = (char *) HvARRAY(hv);
2061 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2062 + sizeof(struct xpvhv_aux), char);
2064 HvARRAY(hv) = (HE**)array;
2067 #ifdef PERL_HASH_RANDOMIZE_KEYS
2068 if (PL_HASH_RAND_BITS_ENABLED) {
2069 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2070 if (PL_HASH_RAND_BITS_ENABLED == 1)
2071 PL_hash_rand_bits += ptr_hash((PTRV)array);
2072 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2074 iter->xhv_rand = (U32)PL_hash_rand_bits;
2080 return hv_auxinit_internal(iter);
2084 =for apidoc hv_iterinit
2086 Prepares a starting point to traverse a hash table. Returns the number of
2087 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
2088 currently only meaningful for hashes without tie magic.
2090 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2091 hash buckets that happen to be in use. If you still need that esoteric
2092 value, you can get it through the macro C<HvFILL(hv)>.
2099 Perl_hv_iterinit(pTHX_ HV *hv)
2101 PERL_ARGS_ASSERT_HV_ITERINIT;
2104 struct xpvhv_aux * iter = HvAUX(hv);
2105 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2106 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2108 hv_free_ent(hv, entry);
2110 iter = HvAUX(hv); /* may have been reallocated */
2111 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2112 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2113 #ifdef PERL_HASH_RANDOMIZE_KEYS
2114 iter->xhv_last_rand = iter->xhv_rand;
2120 /* used to be xhv->xhv_fill before 5.004_65 */
2121 return HvTOTALKEYS(hv);
2125 Perl_hv_riter_p(pTHX_ HV *hv) {
2126 struct xpvhv_aux *iter;
2128 PERL_ARGS_ASSERT_HV_RITER_P;
2130 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2131 return &(iter->xhv_riter);
2135 Perl_hv_eiter_p(pTHX_ HV *hv) {
2136 struct xpvhv_aux *iter;
2138 PERL_ARGS_ASSERT_HV_EITER_P;
2140 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2141 return &(iter->xhv_eiter);
2145 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2146 struct xpvhv_aux *iter;
2148 PERL_ARGS_ASSERT_HV_RITER_SET;
2156 iter = hv_auxinit(hv);
2158 iter->xhv_riter = riter;
2162 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2163 struct xpvhv_aux *iter;
2165 PERL_ARGS_ASSERT_HV_RAND_SET;
2167 #ifdef PERL_HASH_RANDOMIZE_KEYS
2171 iter = hv_auxinit(hv);
2173 iter->xhv_rand = new_xhv_rand;
2175 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2180 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2181 struct xpvhv_aux *iter;
2183 PERL_ARGS_ASSERT_HV_EITER_SET;
2188 /* 0 is the default so don't go malloc()ing a new structure just to
2193 iter = hv_auxinit(hv);
2195 iter->xhv_eiter = eiter;
2199 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2202 struct xpvhv_aux *iter;
2206 PERL_ARGS_ASSERT_HV_NAME_SET;
2209 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2213 if (iter->xhv_name_u.xhvnameu_name) {
2214 if(iter->xhv_name_count) {
2215 if(flags & HV_NAME_SETALL) {
2216 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2217 HEK **hekp = name + (
2218 iter->xhv_name_count < 0
2219 ? -iter->xhv_name_count
2220 : iter->xhv_name_count
2222 while(hekp-- > name+1)
2223 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2224 /* The first elem may be null. */
2225 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2227 iter = HvAUX(hv); /* may been realloced */
2228 spot = &iter->xhv_name_u.xhvnameu_name;
2229 iter->xhv_name_count = 0;
2232 if(iter->xhv_name_count > 0) {
2233 /* shift some things over */
2235 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2237 spot = iter->xhv_name_u.xhvnameu_names;
2238 spot[iter->xhv_name_count] = spot[1];
2240 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2242 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2243 unshare_hek_or_pvn(*spot, 0, 0, 0);
2247 else if (flags & HV_NAME_SETALL) {
2248 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2249 iter = HvAUX(hv); /* may been realloced */
2250 spot = &iter->xhv_name_u.xhvnameu_name;
2253 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2254 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2255 iter->xhv_name_count = -2;
2256 spot = iter->xhv_name_u.xhvnameu_names;
2257 spot[1] = existing_name;
2260 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2265 iter = hv_auxinit(hv);
2266 spot = &iter->xhv_name_u.xhvnameu_name;
2268 PERL_HASH(hash, name, len);
2269 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2273 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2278 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2279 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2280 if (flags & SVf_UTF8)
2281 return (bytes_cmp_utf8(
2282 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2283 (const U8*)pv, pvlen) == 0);
2285 return (bytes_cmp_utf8(
2286 (const U8*)pv, pvlen,
2287 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2290 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2291 || memEQ(HEK_KEY(hek), pv, pvlen));
2295 =for apidoc hv_ename_add
2297 Adds a name to a stash's internal list of effective names. See
2300 This is called when a stash is assigned to a new location in the symbol
2307 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2310 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2313 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2316 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2318 PERL_HASH(hash, name, len);
2320 if (aux->xhv_name_count) {
2321 I32 count = aux->xhv_name_count;
2322 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2323 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2324 while (hekp-- > xhv_name)
2328 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2329 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2330 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2332 if (hekp == xhv_name && count < 0)
2333 aux->xhv_name_count = -count;
2337 if (count < 0) aux->xhv_name_count--, count = -count;
2338 else aux->xhv_name_count++;
2339 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2340 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2343 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2346 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2347 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2348 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2351 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2352 aux->xhv_name_count = existing_name ? 2 : -2;
2353 *aux->xhv_name_u.xhvnameu_names = existing_name;
2354 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2359 =for apidoc hv_ename_delete
2361 Removes a name from a stash's internal list of effective names. If this is
2362 the name returned by C<HvENAME>, then another name in the list will take
2363 its place (C<HvENAME> will use it).
2365 This is called when a stash is deleted from the symbol table.
2371 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2373 struct xpvhv_aux *aux;
2375 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2378 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2380 if (!SvOOK(hv)) return;
2383 if (!aux->xhv_name_u.xhvnameu_name) return;
2385 if (aux->xhv_name_count) {
2386 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2387 I32 const count = aux->xhv_name_count;
2388 HEK **victim = namep + (count < 0 ? -count : count);
2389 while (victim-- > namep + 1)
2391 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2392 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2393 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2395 unshare_hek_or_pvn(*victim, 0, 0, 0);
2396 aux = HvAUX(hv); /* may been realloced */
2397 if (count < 0) ++aux->xhv_name_count;
2398 else --aux->xhv_name_count;
2400 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2402 ) { /* if there are none left */
2404 aux->xhv_name_u.xhvnameu_names = NULL;
2405 aux->xhv_name_count = 0;
2408 /* Move the last one back to fill the empty slot. It
2409 does not matter what order they are in. */
2410 *victim = *(namep + (count < 0 ? -count : count) - 1);
2415 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2416 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2417 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2419 aux->xhv_name_count = -count;
2423 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2424 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2425 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2426 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2428 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2429 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2430 *aux->xhv_name_u.xhvnameu_names = namehek;
2431 aux->xhv_name_count = -1;
2436 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2437 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2438 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2440 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2441 return &(iter->xhv_backreferences);
2446 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2449 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2454 av = HvAUX(hv)->xhv_backreferences;
2457 HvAUX(hv)->xhv_backreferences = 0;
2458 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2459 if (SvTYPE(av) == SVt_PVAV)
2460 SvREFCNT_dec_NN(av);
2465 hv_iternext is implemented as a macro in hv.h
2467 =for apidoc hv_iternext
2469 Returns entries from a hash iterator. See C<hv_iterinit>.
2471 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2472 iterator currently points to, without losing your place or invalidating your
2473 iterator. Note that in this case the current entry is deleted from the hash
2474 with your iterator holding the last reference to it. Your iterator is flagged
2475 to free the entry on the next call to C<hv_iternext>, so you must not discard
2476 your iterator immediately else the entry will leak - call C<hv_iternext> to
2477 trigger the resource deallocation.
2479 =for apidoc hv_iternext_flags
2481 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2482 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2483 set the placeholders keys (for restricted hashes) will be returned in addition
2484 to normal keys. By default placeholders are automatically skipped over.
2485 Currently a placeholder is implemented with a value that is
2486 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2487 restricted hashes may change, and the implementation currently is
2488 insufficiently abstracted for any change to be tidy.
2494 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2501 struct xpvhv_aux *iter;
2503 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2505 xhv = (XPVHV*)SvANY(hv);
2508 /* Too many things (well, pp_each at least) merrily assume that you can
2509 call hv_iternext without calling hv_iterinit, so we'll have to deal
2515 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2516 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2517 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2518 SV * const key = sv_newmortal();
2520 sv_setsv(key, HeSVKEY_force(entry));
2521 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2522 HeSVKEY_set(entry, NULL);
2528 /* one HE per MAGICAL hash */
2529 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2530 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2532 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2534 HeKEY_hek(entry) = hek;
2535 HeKLEN(entry) = HEf_SVKEY;
2537 magic_nextpack(MUTABLE_SV(hv),mg,key);
2539 /* force key to stay around until next time */
2540 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2541 return entry; /* beware, hent_val is not set */
2543 SvREFCNT_dec(HeVAL(entry));
2544 Safefree(HeKEY_hek(entry));
2546 iter = HvAUX(hv); /* may been realloced */
2547 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2552 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2553 if (!entry && SvRMAGICAL((const SV *)hv)
2554 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2557 /* The prime_env_iter() on VMS just loaded up new hash values
2558 * so the iteration count needs to be reset back to the beginning
2562 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2567 /* hv_iterinit now ensures this. */
2568 assert (HvARRAY(hv));
2570 /* At start of hash, entry is NULL. */
2573 entry = HeNEXT(entry);
2574 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2576 * Skip past any placeholders -- don't want to include them in
2579 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2580 entry = HeNEXT(entry);
2585 #ifdef PERL_HASH_RANDOMIZE_KEYS
2586 if (iter->xhv_last_rand != iter->xhv_rand) {
2587 if (iter->xhv_riter != -1) {
2588 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2589 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2593 iter = HvAUX(hv); /* may been realloced */
2594 iter->xhv_last_rand = iter->xhv_rand;
2598 /* Skip the entire loop if the hash is empty. */
2599 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2600 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2602 /* OK. Come to the end of the current list. Grab the next one. */
2604 iter->xhv_riter++; /* HvRITER(hv)++ */
2605 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2606 /* There is no next one. End of the hash. */
2607 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2608 #ifdef PERL_HASH_RANDOMIZE_KEYS
2609 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2613 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2615 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2616 /* If we have an entry, but it's a placeholder, don't count it.
2618 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2619 entry = HeNEXT(entry);
2621 /* Will loop again if this linked list starts NULL
2622 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2623 or if we run through it and find only placeholders. */
2627 iter->xhv_riter = -1;
2628 #ifdef PERL_HASH_RANDOMIZE_KEYS
2629 iter->xhv_last_rand = iter->xhv_rand;
2633 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2635 hv_free_ent(hv, oldentry);
2638 iter = HvAUX(hv); /* may been realloced */
2639 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2644 =for apidoc hv_iterkey
2646 Returns the key from the current position of the hash iterator. See
2653 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2655 PERL_ARGS_ASSERT_HV_ITERKEY;
2657 if (HeKLEN(entry) == HEf_SVKEY) {
2659 char * const p = SvPV(HeKEY_sv(entry), len);
2664 *retlen = HeKLEN(entry);
2665 return HeKEY(entry);
2669 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2671 =for apidoc hv_iterkeysv
2673 Returns the key as an C<SV*> from the current position of the hash
2674 iterator. The return value will always be a mortal copy of the key. Also
2681 Perl_hv_iterkeysv(pTHX_ HE *entry)
2683 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2685 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2689 =for apidoc hv_iterval
2691 Returns the value from the current position of the hash iterator. See
2698 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2700 PERL_ARGS_ASSERT_HV_ITERVAL;
2702 if (SvRMAGICAL(hv)) {
2703 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2704 SV* const sv = sv_newmortal();
2705 if (HeKLEN(entry) == HEf_SVKEY)
2706 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2708 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2712 return HeVAL(entry);
2716 =for apidoc hv_iternextsv
2718 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2725 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2727 HE * const he = hv_iternext_flags(hv, 0);
2729 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2733 *key = hv_iterkey(he, retlen);
2734 return hv_iterval(hv, he);
2741 =for apidoc hv_magic
2743 Adds magic to a hash. See C<sv_magic>.
2748 /* possibly free a shared string if no one has access to it
2749 * len and hash must both be valid for str.
2752 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2754 unshare_hek_or_pvn (NULL, str, len, hash);
2759 Perl_unshare_hek(pTHX_ HEK *hek)
2762 unshare_hek_or_pvn(hek, NULL, 0, 0);
2765 /* possibly free a shared string if no one has access to it
2766 hek if non-NULL takes priority over the other 3, else str, len and hash
2767 are used. If so, len and hash must both be valid for str.
2770 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2775 bool is_utf8 = FALSE;
2777 const char * const save = str;
2778 struct shared_he *he = NULL;
2781 /* Find the shared he which is just before us in memory. */
2782 he = (struct shared_he *)(((char *)hek)
2783 - STRUCT_OFFSET(struct shared_he,
2786 /* Assert that the caller passed us a genuine (or at least consistent)
2788 assert (he->shared_he_he.hent_hek == hek);
2790 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2791 --he->shared_he_he.he_valu.hent_refcount;
2795 hash = HEK_HASH(hek);
2796 } else if (len < 0) {
2797 STRLEN tmplen = -len;
2799 /* See the note in hv_fetch(). --jhi */
2800 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2803 k_flags = HVhek_UTF8;
2805 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2808 /* what follows was the moral equivalent of:
2809 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2811 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2813 xhv = (XPVHV*)SvANY(PL_strtab);
2814 /* assert(xhv_array != 0) */
2815 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2817 const HE *const he_he = &(he->shared_he_he);
2818 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2823 const int flags_masked = k_flags & HVhek_MASK;
2824 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2825 if (HeHASH(entry) != hash) /* strings can't be equal */
2827 if (HeKLEN(entry) != len)
2829 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2831 if (HeKFLAGS(entry) != flags_masked)
2838 if (--entry->he_valu.hent_refcount == 0) {
2839 *oentry = HeNEXT(entry);
2841 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2846 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2847 "Attempt to free nonexistent shared string '%s'%s"
2849 hek ? HEK_KEY(hek) : str,
2850 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2851 if (k_flags & HVhek_FREEKEY)
2855 /* get a (constant) string ptr from the global string table
2856 * string will get added if it is not already there.
2857 * len and hash must both be valid for str.
2860 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2862 bool is_utf8 = FALSE;
2864 const char * const save = str;
2866 PERL_ARGS_ASSERT_SHARE_HEK;
2869 STRLEN tmplen = -len;
2871 /* See the note in hv_fetch(). --jhi */
2872 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2874 /* If we were able to downgrade here, then than means that we were passed
2875 in a key which only had chars 0-255, but was utf8 encoded. */
2878 /* If we found we were able to downgrade the string to bytes, then
2879 we should flag that it needs upgrading on keys or each. Also flag
2880 that we need share_hek_flags to free the string. */
2883 PERL_HASH(hash, str, len);
2884 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2888 return share_hek_flags (str, len, hash, flags);
2892 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2895 const int flags_masked = flags & HVhek_MASK;
2896 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2897 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2899 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2901 /* what follows is the moral equivalent of:
2903 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2904 hv_store(PL_strtab, str, len, NULL, hash);
2906 Can't rehash the shared string table, so not sure if it's worth
2907 counting the number of entries in the linked list
2910 /* assert(xhv_array != 0) */
2911 entry = (HvARRAY(PL_strtab))[hindex];
2912 for (;entry; entry = HeNEXT(entry)) {
2913 if (HeHASH(entry) != hash) /* strings can't be equal */
2915 if (HeKLEN(entry) != len)
2917 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2919 if (HeKFLAGS(entry) != flags_masked)
2925 /* What used to be head of the list.
2926 If this is NULL, then we're the first entry for this slot, which
2927 means we need to increate fill. */
2928 struct shared_he *new_entry;
2931 HE **const head = &HvARRAY(PL_strtab)[hindex];
2932 HE *const next = *head;
2934 /* We don't actually store a HE from the arena and a regular HEK.
2935 Instead we allocate one chunk of memory big enough for both,
2936 and put the HEK straight after the HE. This way we can find the
2937 HE directly from the HEK.
2940 Newx(k, STRUCT_OFFSET(struct shared_he,
2941 shared_he_hek.hek_key[0]) + len + 2, char);
2942 new_entry = (struct shared_he *)k;
2943 entry = &(new_entry->shared_he_he);
2944 hek = &(new_entry->shared_he_hek);
2946 Copy(str, HEK_KEY(hek), len, char);
2947 HEK_KEY(hek)[len] = 0;
2949 HEK_HASH(hek) = hash;
2950 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2952 /* Still "point" to the HEK, so that other code need not know what
2954 HeKEY_hek(entry) = hek;
2955 entry->he_valu.hent_refcount = 0;
2956 HeNEXT(entry) = next;
2959 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2960 if (!next) { /* initial entry? */
2961 } else if ( DO_HSPLIT(xhv) ) {
2962 const STRLEN oldsize = xhv->xhv_max + 1;
2963 hsplit(PL_strtab, oldsize, oldsize * 2);
2967 ++entry->he_valu.hent_refcount;
2969 if (flags & HVhek_FREEKEY)
2972 return HeKEY_hek(entry);
2976 Perl_hv_placeholders_p(pTHX_ HV *hv)
2978 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2980 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2983 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2986 Perl_die(aTHX_ "panic: hv_placeholders_p");
2989 return &(mg->mg_len);
2994 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2996 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2998 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2999 PERL_UNUSED_CONTEXT;
3001 return mg ? mg->mg_len : 0;
3005 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3007 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3009 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3014 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3015 Perl_die(aTHX_ "panic: hv_placeholders_set");
3017 /* else we don't need to add magic to record 0 placeholders. */
3021 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3026 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3028 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3033 value = &PL_sv_placeholder;
3036 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3039 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3042 case HVrhek_PV_UTF8:
3043 /* Create a string SV that directly points to the bytes in our
3045 value = newSV_type(SVt_PV);
3046 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3047 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3048 /* This stops anything trying to free it */
3049 SvLEN_set(value, 0);
3051 SvREADONLY_on(value);
3052 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3056 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
3057 (UV)he->refcounted_he_data[0]);
3063 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
3065 Generates and returns a C<HV *> representing the content of a
3066 C<refcounted_he> chain.
3067 I<flags> is currently unused and must be zero.
3072 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3076 U32 placeholders, max;
3079 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3082 /* We could chase the chain once to get an idea of the number of keys,
3083 and call ksplit. But for now we'll make a potentially inefficient
3084 hash with only 8 entries in its array. */
3089 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3090 HvARRAY(hv) = (HE**)array;
3096 U32 hash = chain->refcounted_he_hash;
3098 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3100 HE **oentry = &((HvARRAY(hv))[hash & max]);
3101 HE *entry = *oentry;
3104 for (; entry; entry = HeNEXT(entry)) {
3105 if (HeHASH(entry) == hash) {
3106 /* We might have a duplicate key here. If so, entry is older
3107 than the key we've already put in the hash, so if they are
3108 the same, skip adding entry. */
3110 const STRLEN klen = HeKLEN(entry);
3111 const char *const key = HeKEY(entry);
3112 if (klen == chain->refcounted_he_keylen
3113 && (!!HeKUTF8(entry)
3114 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3115 && memEQ(key, REF_HE_KEY(chain), klen))
3118 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3120 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3121 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3122 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3133 = share_hek_flags(REF_HE_KEY(chain),
3134 chain->refcounted_he_keylen,
3135 chain->refcounted_he_hash,
3136 (chain->refcounted_he_data[0]
3137 & (HVhek_UTF8|HVhek_WASUTF8)));
3139 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3141 value = refcounted_he_value(chain);
3142 if (value == &PL_sv_placeholder)
3144 HeVAL(entry) = value;
3146 /* Link it into the chain. */
3147 HeNEXT(entry) = *oentry;
3153 chain = chain->refcounted_he_next;
3157 clear_placeholders(hv, placeholders);
3158 HvTOTALKEYS(hv) -= placeholders;
3161 /* We could check in the loop to see if we encounter any keys with key
3162 flags, but it's probably not worth it, as this per-hash flag is only
3163 really meant as an optimisation for things like Storable. */
3165 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3171 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3173 Search along a C<refcounted_he> chain for an entry with the key specified
3174 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3175 bit set, the key octets are interpreted as UTF-8, otherwise they
3176 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3177 string, or zero if it has not been precomputed. Returns a mortal scalar
3178 representing the value associated with the key, or C<&PL_sv_placeholder>
3179 if there is no value associated with the key.
3185 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3186 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3190 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3192 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3193 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3197 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3198 /* For searching purposes, canonicalise to Latin-1 where possible. */
3199 const char *keyend = keypv + keylen, *p;
3200 STRLEN nonascii_count = 0;
3201 for (p = keypv; p != keyend; p++) {
3202 if (! UTF8_IS_INVARIANT(*p)) {
3203 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3204 goto canonicalised_key;
3210 if (nonascii_count) {
3212 const char *p = keypv, *keyend = keypv + keylen;
3213 keylen -= nonascii_count;
3214 Newx(q, keylen, char);
3217 for (; p != keyend; p++, q++) {
3219 if (UTF8_IS_INVARIANT(c)) {
3224 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3228 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3229 canonicalised_key: ;
3231 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3233 PERL_HASH(hash, keypv, keylen);
3235 for (; chain; chain = chain->refcounted_he_next) {
3238 hash == chain->refcounted_he_hash &&
3239 keylen == chain->refcounted_he_keylen &&
3240 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3241 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3243 hash == HEK_HASH(chain->refcounted_he_hek) &&
3244 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3245 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3246 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3249 if (flags & REFCOUNTED_HE_EXISTS)
3250 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3252 ? NULL : &PL_sv_yes;
3253 return sv_2mortal(refcounted_he_value(chain));
3257 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3261 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3263 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3264 instead of a string/length pair.
3270 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3271 const char *key, U32 hash, U32 flags)
3273 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3274 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3278 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3280 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3287 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3288 SV *key, U32 hash, U32 flags)
3292 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3293 if (flags & REFCOUNTED_HE_KEY_UTF8)
3294 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3296 keypv = SvPV_const(key, keylen);
3298 flags |= REFCOUNTED_HE_KEY_UTF8;
3299 if (!hash && SvIsCOW_shared_hash(key))
3300 hash = SvSHARED_HASH(key);
3301 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3305 =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
3307 Creates a new C<refcounted_he>. This consists of a single key/value
3308 pair and a reference to an existing C<refcounted_he> chain (which may
3309 be empty), and thus forms a longer chain. When using the longer chain,
3310 the new key/value pair takes precedence over any entry for the same key
3311 further along the chain.
3313 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3314 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3315 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3316 a precomputed hash of the key string, or zero if it has not been
3319 I<value> is the scalar value to store for this key. I<value> is copied
3320 by this function, which thus does not take ownership of any reference
3321 to it, and later changes to the scalar will not be reflected in the
3322 value visible in the C<refcounted_he>. Complex types of scalar will not
3323 be stored with referential integrity, but will be coerced to strings.
3324 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3325 value is to be associated with the key; this, as with any non-null value,
3326 takes precedence over the existence of a value for the key further along
3329 I<parent> points to the rest of the C<refcounted_he> chain to be
3330 attached to the new C<refcounted_he>. This function takes ownership
3331 of one reference to I<parent>, and returns one reference to the new
3337 struct refcounted_he *
3338 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3339 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3342 STRLEN value_len = 0;
3343 const char *value_p = NULL;
3347 STRLEN key_offset = 1;
3348 struct refcounted_he *he;
3349 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3351 if (!value || value == &PL_sv_placeholder) {
3352 value_type = HVrhek_delete;
3353 } else if (SvPOK(value)) {
3354 value_type = HVrhek_PV;
3355 } else if (SvIOK(value)) {
3356 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3357 } else if (!SvOK(value)) {
3358 value_type = HVrhek_undef;
3360 value_type = HVrhek_PV;
3362 is_pv = value_type == HVrhek_PV;
3364 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3365 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3366 value_p = SvPV_const(value, value_len);
3368 value_type = HVrhek_PV_UTF8;
3369 key_offset = value_len + 2;
3371 hekflags = value_type;
3373 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3374 /* Canonicalise to Latin-1 where possible. */
3375 const char *keyend = keypv + keylen, *p;
3376 STRLEN nonascii_count = 0;
3377 for (p = keypv; p != keyend; p++) {
3378 if (! UTF8_IS_INVARIANT(*p)) {
3379 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3380 goto canonicalised_key;
3386 if (nonascii_count) {
3388 const char *p = keypv, *keyend = keypv + keylen;
3389 keylen -= nonascii_count;
3390 Newx(q, keylen, char);
3393 for (; p != keyend; p++, q++) {
3395 if (UTF8_IS_INVARIANT(c)) {
3400 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3404 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3405 canonicalised_key: ;
3407 if (flags & REFCOUNTED_HE_KEY_UTF8)
3408 hekflags |= HVhek_UTF8;
3410 PERL_HASH(hash, keypv, keylen);
3413 he = (struct refcounted_he*)
3414 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3418 he = (struct refcounted_he*)
3419 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3423 he->refcounted_he_next = parent;
3426 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3427 he->refcounted_he_val.refcounted_he_u_len = value_len;
3428 } else if (value_type == HVrhek_IV) {
3429 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3430 } else if (value_type == HVrhek_UV) {
3431 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3435 he->refcounted_he_hash = hash;
3436 he->refcounted_he_keylen = keylen;
3437 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3439 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3442 he->refcounted_he_data[0] = hekflags;
3443 he->refcounted_he_refcnt = 1;
3449 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3451 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3452 of a string/length pair.
3457 struct refcounted_he *
3458 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3459 const char *key, U32 hash, SV *value, U32 flags)
3461 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3462 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3466 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3468 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3474 struct refcounted_he *
3475 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3476 SV *key, U32 hash, SV *value, U32 flags)
3480 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3481 if (flags & REFCOUNTED_HE_KEY_UTF8)
3482 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3484 keypv = SvPV_const(key, keylen);
3486 flags |= REFCOUNTED_HE_KEY_UTF8;
3487 if (!hash && SvIsCOW_shared_hash(key))
3488 hash = SvSHARED_HASH(key);
3489 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3493 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3495 Decrements the reference count of a C<refcounted_he> by one. If the
3496 reference count reaches zero the structure's memory is freed, which
3497 (recursively) causes a reduction of its parent C<refcounted_he>'s
3498 reference count. It is safe to pass a null pointer to this function:
3499 no action occurs in this case.
3505 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3509 PERL_UNUSED_CONTEXT;
3512 struct refcounted_he *copy;
3516 new_count = --he->refcounted_he_refcnt;
3517 HINTS_REFCNT_UNLOCK;
3523 #ifndef USE_ITHREADS
3524 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3527 he = he->refcounted_he_next;
3528 PerlMemShared_free(copy);
3533 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3535 Increment the reference count of a C<refcounted_he>. The pointer to the
3536 C<refcounted_he> is also returned. It is safe to pass a null pointer
3537 to this function: no action occurs and a null pointer is returned.
3542 struct refcounted_he *
3543 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3548 PERL_UNUSED_CONTEXT;
3551 he->refcounted_he_refcnt++;
3552 HINTS_REFCNT_UNLOCK;
3558 =for apidoc cop_fetch_label
3560 Returns the label attached to a cop.
3561 The flags pointer may be set to C<SVf_UTF8> or 0.
3566 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3569 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3570 struct refcounted_he *const chain = cop->cop_hints_hash;
3572 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3573 PERL_UNUSED_CONTEXT;
3578 if (chain->refcounted_he_keylen != 1)
3580 if (*REF_HE_KEY(chain) != ':')
3583 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3585 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3588 /* Stop anyone trying to really mess us up by adding their own value for
3590 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3591 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3595 *len = chain->refcounted_he_val.refcounted_he_u_len;
3597 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3598 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3600 return chain->refcounted_he_data + 1;
3604 =for apidoc cop_store_label
3606 Save a label into a C<cop_hints_hash>.
3607 You need to set flags to C<SVf_UTF8>
3614 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3618 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3620 if (flags & ~(SVf_UTF8))
3621 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3623 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3624 if (flags & SVf_UTF8)
3627 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3631 =for apidoc hv_assert
3633 Check that a hash is in an internally consistent state.
3641 Perl_hv_assert(pTHX_ HV *hv)
3646 int placeholders = 0;
3649 const I32 riter = HvRITER_get(hv);
3650 HE *eiter = HvEITER_get(hv);
3652 PERL_ARGS_ASSERT_HV_ASSERT;
3654 (void)hv_iterinit(hv);
3656 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3657 /* sanity check the values */
3658 if (HeVAL(entry) == &PL_sv_placeholder)
3662 /* sanity check the keys */
3663 if (HeSVKEY(entry)) {
3664 NOOP; /* Don't know what to check on SV keys. */
3665 } else if (HeKUTF8(entry)) {
3667 if (HeKWASUTF8(entry)) {
3668 PerlIO_printf(Perl_debug_log,
3669 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3670 (int) HeKLEN(entry), HeKEY(entry));
3673 } else if (HeKWASUTF8(entry))
3676 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3677 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3678 const int nhashkeys = HvUSEDKEYS(hv);
3679 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3681 if (nhashkeys != real) {
3682 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3685 if (nhashplaceholders != placeholders) {
3686 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3690 if (withflags && ! HvHASKFLAGS(hv)) {
3691 PerlIO_printf(Perl_debug_log,
3692 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3697 sv_dump(MUTABLE_SV(hv));
3699 HvRITER_set(hv, riter); /* Restore hash iterator state */
3700 HvEITER_set(hv, eiter);
3706 * ex: set ts=8 sts=4 sw=4 et: