3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
22 A HV structure represents a Perl hash. It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures. The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value. Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
35 #define PERL_HASH_INTERNAL_ACCESS
38 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
39 #define HV_FILL_THRESHOLD 31
41 static const char S_strtab_error[]
42 = "Cannot modify shared string table in hv_%s";
46 #define new_HE() (HE*)safemalloc(sizeof(HE))
47 #define del_HE(p) safefree((char*)p)
56 void ** const root = &PL_body_roots[HE_SVSLOT];
59 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
66 #define new_HE() new_he()
69 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
70 PL_body_roots[HE_SVSLOT] = p; \
78 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
80 const int flags_masked = flags & HVhek_MASK;
84 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
86 Newx(k, HEK_BASESIZE + len + 2, char);
88 Copy(str, HEK_KEY(hek), len, char);
89 HEK_KEY(hek)[len] = 0;
92 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
94 if (flags & HVhek_FREEKEY)
99 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
103 Perl_free_tied_hv_pool(pTHX)
106 HE *he = PL_hv_fetch_ent_mh;
109 Safefree(HeKEY_hek(he));
113 PL_hv_fetch_ent_mh = NULL;
116 #if defined(USE_ITHREADS)
118 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
122 PERL_ARGS_ASSERT_HEK_DUP;
123 PERL_UNUSED_ARG(param);
128 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 /* We already shared this hash key. */
131 (void)share_hek_hek(shared);
135 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
136 HEK_HASH(source), HEK_FLAGS(source));
137 ptr_table_store(PL_ptr_table, source, shared);
143 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
147 PERL_ARGS_ASSERT_HE_DUP;
151 /* look for it in the table first */
152 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
156 /* create anew and remember what it is */
158 ptr_table_store(PL_ptr_table, e, ret);
160 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
161 if (HeKLEN(e) == HEf_SVKEY) {
163 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
164 HeKEY_hek(ret) = (HEK*)k;
165 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
168 /* This is hek_dup inlined, which seems to be important for speed
170 HEK * const source = HeKEY_hek(e);
171 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
174 /* We already shared this hash key. */
175 (void)share_hek_hek(shared);
179 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
180 HEK_HASH(source), HEK_FLAGS(source));
181 ptr_table_store(PL_ptr_table, source, shared);
183 HeKEY_hek(ret) = shared;
186 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
188 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
191 #endif /* USE_ITHREADS */
194 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
197 SV * const sv = sv_newmortal();
199 PERL_ARGS_ASSERT_HV_NOTALLOWED;
201 if (!(flags & HVhek_FREEKEY)) {
202 sv_setpvn(sv, key, klen);
205 /* Need to free saved eventually assign to mortal SV */
206 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
207 sv_usepvn(sv, (char *) key, klen);
209 if (flags & HVhek_UTF8) {
212 Perl_croak(aTHX_ msg, SVfARG(sv));
215 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
221 Stores an SV in a hash. The hash key is specified as C<key> and the
222 absolute value of C<klen> is the length of the key. If C<klen> is
223 negative the key is assumed to be in UTF-8-encoded Unicode. The
224 C<hash> parameter is the precomputed hash value; if it is zero then
225 Perl will compute it.
227 The return value will be
228 NULL if the operation failed or if the value did not need to be actually
229 stored within the hash (as in the case of tied hashes). Otherwise it can
230 be dereferenced to get the original C<SV*>. Note that the caller is
231 responsible for suitably incrementing the reference count of C<val> before
232 the call, and decrementing it if the function returned NULL. Effectively
233 a successful hv_store takes ownership of one reference to C<val>. This is
234 usually what you want; a newly created SV has a reference count of one, so
235 if all your code does is create SVs then store them in a hash, hv_store
236 will own the only reference to the new SV, and your code doesn't need to do
237 anything further to tidy up. hv_store is not implemented as a call to
238 hv_store_ent, and does not create a temporary SV for the key, so if your
239 key data is not already in SV form then use hv_store in preference to
242 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
243 information on how to use this function on tied hashes.
245 =for apidoc hv_store_ent
247 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
248 parameter is the precomputed hash value; if it is zero then Perl will
249 compute it. The return value is the new hash entry so created. It will be
250 NULL if the operation failed or if the value did not need to be actually
251 stored within the hash (as in the case of tied hashes). Otherwise the
252 contents of the return value can be accessed using the C<He?> macros
253 described here. Note that the caller is responsible for suitably
254 incrementing the reference count of C<val> before the call, and
255 decrementing it if the function returned NULL. Effectively a successful
256 hv_store_ent takes ownership of one reference to C<val>. This is
257 usually what you want; a newly created SV has a reference count of one, so
258 if all your code does is create SVs then store them in a hash, hv_store
259 will own the only reference to the new SV, and your code doesn't need to do
260 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
261 unlike C<val> it does not take ownership of it, so maintaining the correct
262 reference count on C<key> is entirely the caller's responsibility. hv_store
263 is not implemented as a call to hv_store_ent, and does not create a temporary
264 SV for the key, so if your key data is not already in SV form then use
265 hv_store in preference to hv_store_ent.
267 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
268 information on how to use this function on tied hashes.
270 =for apidoc hv_exists
272 Returns a boolean indicating whether the specified hash key exists. The
273 absolute value of C<klen> is the length of the key. If C<klen> is
274 negative the key is assumed to be in UTF-8-encoded Unicode.
278 Returns the SV which corresponds to the specified key in the hash.
279 The absolute value of C<klen> is the length of the key. If C<klen> is
280 negative the key is assumed to be in UTF-8-encoded Unicode. If
281 C<lval> is set then the fetch will be part of a store. This means that if
282 there is no value in the hash associated with the given key, then one is
283 created and a pointer to it is returned. The C<SV*> it points to can be
284 assigned to. But always check that the
285 return value is non-null before dereferencing it to an C<SV*>.
287 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
288 information on how to use this function on tied hashes.
290 =for apidoc hv_exists_ent
292 Returns a boolean indicating whether
293 the specified hash key exists. C<hash>
294 can be a valid precomputed hash value, or 0 to ask for it to be
300 /* returns an HE * structure with the all fields set */
301 /* note that hent_val will be a mortal sv for MAGICAL hashes */
303 =for apidoc hv_fetch_ent
305 Returns the hash entry which corresponds to the specified key in the hash.
306 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
307 if you want the function to compute it. IF C<lval> is set then the fetch
308 will be part of a store. Make sure the return value is non-null before
309 accessing it. The return value when C<hv> is a tied hash is a pointer to a
310 static location, so be sure to make a copy of the structure if you need to
313 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
314 information on how to use this function on tied hashes.
319 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
321 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
322 const int action, SV *val, const U32 hash)
327 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
336 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
340 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
341 int flags, int action, SV *val, U32 hash)
350 const int return_svp = action & HV_FETCH_JUST_SV;
354 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
357 assert(SvTYPE(hv) == SVt_PVHV);
359 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
361 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
362 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
363 if (uf->uf_set == NULL) {
364 SV* obj = mg->mg_obj;
367 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
368 ((flags & HVhek_UTF8)
372 mg->mg_obj = keysv; /* pass key */
373 uf->uf_index = action; /* pass action */
374 magic_getuvar(MUTABLE_SV(hv), mg);
375 keysv = mg->mg_obj; /* may have changed */
378 /* If the key may have changed, then we need to invalidate
379 any passed-in computed hash value. */
385 if (flags & HVhek_FREEKEY)
387 key = SvPV_const(keysv, klen);
388 is_utf8 = (SvUTF8(keysv) != 0);
389 if (SvIsCOW_shared_hash(keysv)) {
390 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
392 flags = is_utf8 ? HVhek_UTF8 : 0;
395 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
398 if (action & HV_DELETE) {
399 return (void *) hv_delete_common(hv, keysv, key, klen,
400 flags, action, hash);
403 xhv = (XPVHV*)SvANY(hv);
405 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
406 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
407 || SvGMAGICAL((const SV *)hv))
409 /* FIXME should be able to skimp on the HE/HEK here when
410 HV_FETCH_JUST_SV is true. */
412 keysv = newSVpvn_utf8(key, klen, is_utf8);
414 keysv = newSVsv(keysv);
417 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
419 /* grab a fake HE/HEK pair from the pool or make a new one */
420 entry = PL_hv_fetch_ent_mh;
422 PL_hv_fetch_ent_mh = HeNEXT(entry);
426 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
427 HeKEY_hek(entry) = (HEK*)k;
429 HeNEXT(entry) = NULL;
430 HeSVKEY_set(entry, keysv);
432 sv_upgrade(sv, SVt_PVLV);
434 /* so we can free entry when freeing sv */
435 LvTARG(sv) = MUTABLE_SV(entry);
437 /* XXX remove at some point? */
438 if (flags & HVhek_FREEKEY)
442 return entry ? (void *) &HeVAL(entry) : NULL;
444 return (void *) entry;
446 #ifdef ENV_IS_CASELESS
447 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
449 for (i = 0; i < klen; ++i)
450 if (isLOWER(key[i])) {
451 /* Would be nice if we had a routine to do the
452 copy and upercase in a single pass through. */
453 const char * const nkey = strupr(savepvn(key,klen));
454 /* Note that this fetch is for nkey (the uppercased
455 key) whereas the store is for key (the original) */
456 void *result = hv_common(hv, NULL, nkey, klen,
457 HVhek_FREEKEY, /* free nkey */
458 0 /* non-LVAL fetch */
459 | HV_DISABLE_UVAR_XKEY
462 0 /* compute hash */);
463 if (!result && (action & HV_FETCH_LVALUE)) {
464 /* This call will free key if necessary.
465 Do it this way to encourage compiler to tail
467 result = hv_common(hv, keysv, key, klen, flags,
469 | HV_DISABLE_UVAR_XKEY
473 if (flags & HVhek_FREEKEY)
481 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
482 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
483 || SvGMAGICAL((const SV *)hv)) {
484 /* I don't understand why hv_exists_ent has svret and sv,
485 whereas hv_exists only had one. */
486 SV * const svret = sv_newmortal();
489 if (keysv || is_utf8) {
491 keysv = newSVpvn_utf8(key, klen, TRUE);
493 keysv = newSVsv(keysv);
495 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
497 mg_copy(MUTABLE_SV(hv), sv, key, klen);
499 if (flags & HVhek_FREEKEY)
501 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
502 /* This cast somewhat evil, but I'm merely using NULL/
503 not NULL to return the boolean exists.
504 And I know hv is not NULL. */
505 return SvTRUE(svret) ? (void *)hv : NULL;
507 #ifdef ENV_IS_CASELESS
508 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
509 /* XXX This code isn't UTF8 clean. */
510 char * const keysave = (char * const)key;
511 /* Will need to free this, so set FREEKEY flag. */
512 key = savepvn(key,klen);
513 key = (const char*)strupr((char*)key);
518 if (flags & HVhek_FREEKEY) {
521 flags |= HVhek_FREEKEY;
525 else if (action & HV_FETCH_ISSTORE) {
528 hv_magic_check (hv, &needs_copy, &needs_store);
530 const bool save_taint = TAINT_get;
531 if (keysv || is_utf8) {
533 keysv = newSVpvn_utf8(key, klen, TRUE);
536 TAINT_set(SvTAINTED(keysv));
537 keysv = sv_2mortal(newSVsv(keysv));
538 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
540 mg_copy(MUTABLE_SV(hv), val, key, klen);
543 TAINT_IF(save_taint);
544 #ifdef NO_TAINT_SUPPORT
545 PERL_UNUSED_VAR(save_taint);
548 if (flags & HVhek_FREEKEY)
552 #ifdef ENV_IS_CASELESS
553 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
554 /* XXX This code isn't UTF8 clean. */
555 const char *keysave = key;
556 /* Will need to free this, so set FREEKEY flag. */
557 key = savepvn(key,klen);
558 key = (const char*)strupr((char*)key);
563 if (flags & HVhek_FREEKEY) {
566 flags |= HVhek_FREEKEY;
574 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
575 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
576 || (SvRMAGICAL((const SV *)hv)
577 && mg_find((const SV *)hv, PERL_MAGIC_env))
582 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
584 HvARRAY(hv) = (HE**)array;
586 #ifdef DYNAMIC_ENV_FETCH
587 else if (action & HV_FETCH_ISEXISTS) {
588 /* for an %ENV exists, if we do an insert it's by a recursive
589 store call, so avoid creating HvARRAY(hv) right now. */
593 /* XXX remove at some point? */
594 if (flags & HVhek_FREEKEY)
601 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
602 char * const keysave = (char *)key;
603 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
607 flags &= ~HVhek_UTF8;
608 if (key != keysave) {
609 if (flags & HVhek_FREEKEY)
611 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
612 /* If the caller calculated a hash, it was on the sequence of
613 octets that are the UTF-8 form. We've now changed the sequence
614 of octets stored to that of the equivalent byte representation,
615 so the hash we need is different. */
621 if (keysv && (SvIsCOW_shared_hash(keysv)))
622 hash = SvSHARED_HASH(keysv);
624 PERL_HASH(hash, key, klen);
627 masked_flags = (flags & HVhek_MASK);
629 #ifdef DYNAMIC_ENV_FETCH
630 if (!HvARRAY(hv)) entry = NULL;
634 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
636 for (; entry; entry = HeNEXT(entry)) {
637 if (HeHASH(entry) != hash) /* strings can't be equal */
639 if (HeKLEN(entry) != (I32)klen)
641 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
643 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
646 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
647 if (HeKFLAGS(entry) != masked_flags) {
648 /* We match if HVhek_UTF8 bit in our flags and hash key's
649 match. But if entry was set previously with HVhek_WASUTF8
650 and key now doesn't (or vice versa) then we should change
651 the key's flag, as this is assignment. */
652 if (HvSHAREKEYS(hv)) {
653 /* Need to swap the key we have for a key with the flags we
654 need. As keys are shared we can't just write to the
655 flag, so we share the new one, unshare the old one. */
656 HEK * const new_hek = share_hek_flags(key, klen, hash,
658 unshare_hek (HeKEY_hek(entry));
659 HeKEY_hek(entry) = new_hek;
661 else if (hv == PL_strtab) {
662 /* PL_strtab is usually the only hash without HvSHAREKEYS,
663 so putting this test here is cheap */
664 if (flags & HVhek_FREEKEY)
666 Perl_croak(aTHX_ S_strtab_error,
667 action & HV_FETCH_LVALUE ? "fetch" : "store");
670 HeKFLAGS(entry) = masked_flags;
671 if (masked_flags & HVhek_ENABLEHVKFLAGS)
674 if (HeVAL(entry) == &PL_sv_placeholder) {
675 /* yes, can store into placeholder slot */
676 if (action & HV_FETCH_LVALUE) {
678 /* This preserves behaviour with the old hv_fetch
679 implementation which at this point would bail out
680 with a break; (at "if we find a placeholder, we
681 pretend we haven't found anything")
683 That break mean that if a placeholder were found, it
684 caused a call into hv_store, which in turn would
685 check magic, and if there is no magic end up pretty
686 much back at this point (in hv_store's code). */
689 /* LVAL fetch which actually needs a store. */
691 HvPLACEHOLDERS(hv)--;
694 if (val != &PL_sv_placeholder)
695 HvPLACEHOLDERS(hv)--;
698 } else if (action & HV_FETCH_ISSTORE) {
699 SvREFCNT_dec(HeVAL(entry));
702 } else if (HeVAL(entry) == &PL_sv_placeholder) {
703 /* if we find a placeholder, we pretend we haven't found
707 if (flags & HVhek_FREEKEY)
710 return entry ? (void *) &HeVAL(entry) : NULL;
714 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
715 if (!(action & HV_FETCH_ISSTORE)
716 && SvRMAGICAL((const SV *)hv)
717 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
719 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
721 sv = newSVpvn(env,len);
723 return hv_common(hv, keysv, key, klen, flags,
724 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
730 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
731 hv_notallowed(flags, key, klen,
732 "Attempt to access disallowed key '%"SVf"' in"
733 " a restricted hash");
735 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
736 /* Not doing some form of store, so return failure. */
737 if (flags & HVhek_FREEKEY)
741 if (action & HV_FETCH_LVALUE) {
742 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
744 /* At this point the old hv_fetch code would call to hv_store,
745 which in turn might do some tied magic. So we need to make that
746 magic check happen. */
747 /* gonna assign to this, so it better be there */
748 /* If a fetch-as-store fails on the fetch, then the action is to
749 recurse once into "hv_store". If we didn't do this, then that
750 recursive call would call the key conversion routine again.
751 However, as we replace the original key with the converted
752 key, this would result in a double conversion, which would show
753 up as a bug if the conversion routine is not idempotent.
754 Hence the use of HV_DISABLE_UVAR_XKEY. */
755 return hv_common(hv, keysv, key, klen, flags,
756 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
758 /* XXX Surely that could leak if the fetch-was-store fails?
759 Just like the hv_fetch. */
763 /* Welcome to hv_store... */
766 /* Not sure if we can get here. I think the only case of oentry being
767 NULL is for %ENV with dynamic env fetch. But that should disappear
768 with magic in the previous code. */
771 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
773 HvARRAY(hv) = (HE**)array;
776 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
779 /* share_hek_flags will do the free for us. This might be considered
782 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
783 else if (hv == PL_strtab) {
784 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
785 this test here is cheap */
786 if (flags & HVhek_FREEKEY)
788 Perl_croak(aTHX_ S_strtab_error,
789 action & HV_FETCH_LVALUE ? "fetch" : "store");
791 else /* gotta do the real thing */
792 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
795 if (!*oentry && SvOOK(hv)) {
796 /* initial entry, and aux struct present. */
797 struct xpvhv_aux *const aux = HvAUX(hv);
798 if (aux->xhv_fill_lazy)
799 ++aux->xhv_fill_lazy;
802 #ifdef PERL_HASH_RANDOMIZE_KEYS
803 /* This logic semi-randomizes the insert order in a bucket.
804 * Either we insert into the top, or the slot below the top,
805 * making it harder to see if there is a collision. We also
806 * reset the iterator randomizer if there is one.
808 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
810 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
811 if ( PL_hash_rand_bits & 1 ) {
812 HeNEXT(entry) = HeNEXT(*oentry);
813 HeNEXT(*oentry) = entry;
815 HeNEXT(entry) = *oentry;
821 HeNEXT(entry) = *oentry;
824 #ifdef PERL_HASH_RANDOMIZE_KEYS
826 /* Currently this makes various tests warn in annoying ways.
827 * So Silenced for now. - Yves | bogus end of comment =>* /
828 if (HvAUX(hv)->xhv_riter != -1) {
829 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
830 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
835 if (PL_HASH_RAND_BITS_ENABLED) {
836 if (PL_HASH_RAND_BITS_ENABLED == 1)
837 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
838 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
840 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
844 if (val == &PL_sv_placeholder)
845 HvPLACEHOLDERS(hv)++;
846 if (masked_flags & HVhek_ENABLEHVKFLAGS)
849 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
850 if ( DO_HSPLIT(xhv) ) {
851 const STRLEN oldsize = xhv->xhv_max + 1;
852 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
854 if (items /* hash has placeholders */
855 && !SvREADONLY(hv) /* but is not a restricted hash */) {
856 /* If this hash previously was a "restricted hash" and had
857 placeholders, but the "restricted" flag has been turned off,
858 then the placeholders no longer serve any useful purpose.
859 However, they have the downsides of taking up RAM, and adding
860 extra steps when finding used values. It's safe to clear them
861 at this point, even though Storable rebuilds restricted hashes by
862 putting in all the placeholders (first) before turning on the
863 readonly flag, because Storable always pre-splits the hash.
864 If we're lucky, then we may clear sufficient placeholders to
865 avoid needing to split the hash at all. */
866 clear_placeholders(hv, items);
868 hsplit(hv, oldsize, oldsize * 2);
870 hsplit(hv, oldsize, oldsize * 2);
874 return entry ? (void *) &HeVAL(entry) : NULL;
876 return (void *) entry;
880 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
882 const MAGIC *mg = SvMAGIC(hv);
884 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
889 if (isUPPER(mg->mg_type)) {
891 if (mg->mg_type == PERL_MAGIC_tied) {
892 *needs_store = FALSE;
893 return; /* We've set all there is to set. */
896 mg = mg->mg_moremagic;
901 =for apidoc hv_scalar
903 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
909 Perl_hv_scalar(pTHX_ HV *hv)
913 PERL_ARGS_ASSERT_HV_SCALAR;
915 if (SvRMAGICAL(hv)) {
916 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
918 return magic_scalarpack(hv, mg);
922 if (HvTOTALKEYS((const HV *)hv))
923 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
924 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
932 =for apidoc hv_delete
934 Deletes a key/value pair in the hash. The value's SV is removed from
935 the hash, made mortal, and returned to the caller. The absolute
936 value of C<klen> is the length of the key. If C<klen> is negative the
937 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
938 will normally be zero; if set to G_DISCARD then NULL will be returned.
939 NULL will also be returned if the key is not found.
941 =for apidoc hv_delete_ent
943 Deletes a key/value pair in the hash. The value SV is removed from the hash,
944 made mortal, and returned to the caller. The C<flags> value will normally be
945 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
946 returned if the key is not found. C<hash> can be a valid precomputed hash
947 value, or 0 to ask for it to be computed.
953 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
954 int k_flags, I32 d_flags, U32 hash)
960 HE *const *first_entry;
961 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
964 if (SvRMAGICAL(hv)) {
967 hv_magic_check (hv, &needs_copy, &needs_store);
971 entry = (HE *) hv_common(hv, keysv, key, klen,
972 k_flags & ~HVhek_FREEKEY,
973 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
975 sv = entry ? HeVAL(entry) : NULL;
981 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
982 /* No longer an element */
983 sv_unmagic(sv, PERL_MAGIC_tiedelem);
986 return NULL; /* element cannot be deleted */
988 #ifdef ENV_IS_CASELESS
989 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
990 /* XXX This code isn't UTF8 clean. */
991 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
992 if (k_flags & HVhek_FREEKEY) {
995 key = strupr(SvPVX(keysv));
1004 xhv = (XPVHV*)SvANY(hv);
1008 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1009 const char * const keysave = key;
1010 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1013 k_flags |= HVhek_UTF8;
1015 k_flags &= ~HVhek_UTF8;
1016 if (key != keysave) {
1017 if (k_flags & HVhek_FREEKEY) {
1018 /* This shouldn't happen if our caller does what we expect,
1019 but strictly the API allows it. */
1022 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1024 HvHASKFLAGS_on(MUTABLE_SV(hv));
1028 if (keysv && (SvIsCOW_shared_hash(keysv)))
1029 hash = SvSHARED_HASH(keysv);
1031 PERL_HASH(hash, key, klen);
1034 masked_flags = (k_flags & HVhek_MASK);
1036 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1038 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1040 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1044 if (HeHASH(entry) != hash) /* strings can't be equal */
1046 if (HeKLEN(entry) != (I32)klen)
1048 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1050 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1053 if (hv == PL_strtab) {
1054 if (k_flags & HVhek_FREEKEY)
1056 Perl_croak(aTHX_ S_strtab_error, "delete");
1059 /* if placeholder is here, it's already been deleted.... */
1060 if (HeVAL(entry) == &PL_sv_placeholder) {
1061 if (k_flags & HVhek_FREEKEY)
1065 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1066 hv_notallowed(k_flags, key, klen,
1067 "Attempt to delete readonly key '%"SVf"' from"
1068 " a restricted hash");
1070 if (k_flags & HVhek_FREEKEY)
1073 /* If this is a stash and the key ends with ::, then someone is
1074 * deleting a package.
1076 if (HeVAL(entry) && HvENAME_get(hv)) {
1077 gv = (GV *)HeVAL(entry);
1078 if (keysv) key = SvPV(keysv, klen);
1080 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1082 (klen == 1 && key[0] == ':')
1084 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1085 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1086 && HvENAME_get(stash)) {
1087 /* A previous version of this code checked that the
1088 * GV was still in the symbol table by fetching the
1089 * GV with its name. That is not necessary (and
1090 * sometimes incorrect), as HvENAME cannot be set
1091 * on hv if it is not in the symtab. */
1093 /* Hang on to it for a bit. */
1094 SvREFCNT_inc_simple_void_NN(
1095 sv_2mortal((SV *)gv)
1098 else if (klen == 3 && strnEQ(key, "ISA", 3))
1102 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1103 HeVAL(entry) = &PL_sv_placeholder;
1105 /* deletion of method from stash */
1106 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1108 mro_method_changed_in(hv);
1112 * If a restricted hash, rather than really deleting the entry, put
1113 * a placeholder there. This marks the key as being "approved", so
1114 * we can still access via not-really-existing key without raising
1118 /* We'll be saving this slot, so the number of allocated keys
1119 * doesn't go down, but the number placeholders goes up */
1120 HvPLACEHOLDERS(hv)++;
1122 *oentry = HeNEXT(entry);
1123 if(!*first_entry && SvOOK(hv)) {
1124 /* removed last entry, and aux struct present. */
1125 struct xpvhv_aux *const aux = HvAUX(hv);
1126 if (aux->xhv_fill_lazy)
1127 --aux->xhv_fill_lazy;
1129 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1132 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1133 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1134 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1135 hv_free_ent(hv, entry);
1137 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1138 if (xhv->xhv_keys == 0)
1139 HvHASKFLAGS_off(hv);
1142 if (d_flags & G_DISCARD) {
1147 if (mro_changes == 1) mro_isa_changed_in(hv);
1148 else if (mro_changes == 2)
1149 mro_package_moved(NULL, stash, gv, 1);
1153 if (SvREADONLY(hv)) {
1154 hv_notallowed(k_flags, key, klen,
1155 "Attempt to delete disallowed key '%"SVf"' from"
1156 " a restricted hash");
1159 if (k_flags & HVhek_FREEKEY)
1165 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1169 char *a = (char*) HvARRAY(hv);
1172 PERL_ARGS_ASSERT_HSPLIT;
1174 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1175 (void*)hv, (int) oldsize);*/
1178 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1179 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1184 #ifdef PERL_HASH_RANDOMIZE_KEYS
1185 /* the idea of this is that we create a "random" value by hashing the address of
1186 * the array, we then use the low bit to decide if we insert at the top, or insert
1187 * second from top. After each such insert we rotate the hashed value. So we can
1188 * use the same hashed value over and over, and in normal build environments use
1189 * very few ops to do so. ROTL32() should produce a single machine operation. */
1190 if (PL_HASH_RAND_BITS_ENABLED) {
1191 if (PL_HASH_RAND_BITS_ENABLED == 1)
1192 PL_hash_rand_bits += ptr_hash((PTRV)a);
1193 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1198 struct xpvhv_aux *const dest
1199 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1200 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1201 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1202 #ifdef PERL_HASH_RANDOMIZE_KEYS
1203 dest->xhv_rand = (U32)PL_hash_rand_bits;
1205 /* For now, just reset the lazy fill counter.
1206 It would be possible to update the counter in the code below
1208 dest->xhv_fill_lazy = 0;
1212 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1213 HvMAX(hv) = --newsize;
1214 HvARRAY(hv) = (HE**) a;
1216 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1221 HE **oentry = aep + i;
1224 if (!entry) /* non-existent */
1227 U32 j = (HeHASH(entry) & newsize);
1229 *oentry = HeNEXT(entry);
1230 #ifdef PERL_HASH_RANDOMIZE_KEYS
1231 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1232 * insert to top, otherwise rotate the bucket rand 1 bit,
1233 * and use the new low bit to decide if we insert at top,
1234 * or next from top. IOW, we only rotate on a collision.*/
1235 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1236 PL_hash_rand_bits+= ROTL_UV(HeHASH(entry), 17);
1237 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1238 if (PL_hash_rand_bits & 1) {
1239 HeNEXT(entry)= HeNEXT(aep[j]);
1240 HeNEXT(aep[j])= entry;
1242 /* Note, this is structured in such a way as the optimizer
1243 * should eliminate the duplicated code here and below without
1244 * us needing to explicitly use a goto. */
1245 HeNEXT(entry) = aep[j];
1251 /* see comment above about duplicated code */
1252 HeNEXT(entry) = aep[j];
1257 oentry = &HeNEXT(entry);
1261 } while (i++ < oldsize);
1265 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1268 XPVHV* xhv = (XPVHV*)SvANY(hv);
1269 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1273 PERL_ARGS_ASSERT_HV_KSPLIT;
1275 newsize = (I32) newmax; /* possible truncation here */
1276 if (newsize != newmax || newmax <= oldsize)
1278 while ((newsize & (1 + ~newsize)) != newsize) {
1279 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1281 if (newsize < newmax)
1283 if (newsize < newmax)
1284 return; /* overflow detection */
1286 a = (char *) HvARRAY(hv);
1288 hsplit(hv, oldsize, newsize);
1290 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1291 xhv->xhv_max = --newsize;
1292 HvARRAY(hv) = (HE **) a;
1296 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1297 * as tied hashes could play silly buggers and mess us around. We will
1298 * do the right thing during hv_store() afterwards, but still - Yves */
1299 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1300 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1301 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1302 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1304 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1305 hv_max = hv_max / 2; \
1307 HvMAX(hv) = hv_max; \
1312 Perl_newHVhv(pTHX_ HV *ohv)
1315 HV * const hv = newHV();
1318 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1320 hv_max = HvMAX(ohv);
1322 if (!SvMAGICAL((const SV *)ohv)) {
1323 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1325 const bool shared = !!HvSHAREKEYS(ohv);
1326 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1328 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1331 /* In each bucket... */
1332 for (i = 0; i <= hv_max; i++) {
1334 HE *oent = oents[i];
1341 /* Copy the linked list of entries. */
1342 for (; oent; oent = HeNEXT(oent)) {
1343 const U32 hash = HeHASH(oent);
1344 const char * const key = HeKEY(oent);
1345 const STRLEN len = HeKLEN(oent);
1346 const int flags = HeKFLAGS(oent);
1347 HE * const ent = new_HE();
1348 SV *const val = HeVAL(oent);
1350 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1352 = shared ? share_hek_flags(key, len, hash, flags)
1353 : save_hek_flags(key, len, hash, flags);
1364 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1368 /* Iterate over ohv, copying keys and values one at a time. */
1370 const I32 riter = HvRITER_get(ohv);
1371 HE * const eiter = HvEITER_get(ohv);
1372 STRLEN hv_keys = HvTOTALKEYS(ohv);
1374 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1377 while ((entry = hv_iternext_flags(ohv, 0))) {
1378 SV *val = hv_iterval(ohv,entry);
1379 SV * const keysv = HeSVKEY(entry);
1380 val = SvIMMORTAL(val) ? val : newSVsv(val);
1382 (void)hv_store_ent(hv, keysv, val, 0);
1384 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1385 HeHASH(entry), HeKFLAGS(entry));
1387 HvRITER_set(ohv, riter);
1388 HvEITER_set(ohv, eiter);
1395 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1397 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1398 a pointer to a hash (which may have C<%^H> magic, but should be generally
1399 non-magical), or C<NULL> (interpreted as an empty hash). The content
1400 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1401 added to it. A pointer to the new hash is returned.
1407 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1409 HV * const hv = newHV();
1412 STRLEN hv_max = HvMAX(ohv);
1413 STRLEN hv_keys = HvTOTALKEYS(ohv);
1415 const I32 riter = HvRITER_get(ohv);
1416 HE * const eiter = HvEITER_get(ohv);
1421 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1424 while ((entry = hv_iternext_flags(ohv, 0))) {
1425 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1426 SV *heksv = HeSVKEY(entry);
1427 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1428 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1429 (char *)heksv, HEf_SVKEY);
1430 if (heksv == HeSVKEY(entry))
1431 (void)hv_store_ent(hv, heksv, sv, 0);
1433 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1434 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1435 SvREFCNT_dec_NN(heksv);
1438 HvRITER_set(ohv, riter);
1439 HvEITER_set(ohv, eiter);
1441 SvREFCNT_inc_simple_void_NN(hv);
1444 hv_magic(hv, NULL, PERL_MAGIC_hints);
1447 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1449 /* like hv_free_ent, but returns the SV rather than freeing it */
1451 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1456 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1459 if (HeKLEN(entry) == HEf_SVKEY) {
1460 SvREFCNT_dec(HeKEY_sv(entry));
1461 Safefree(HeKEY_hek(entry));
1463 else if (HvSHAREKEYS(hv))
1464 unshare_hek(HeKEY_hek(entry));
1466 Safefree(HeKEY_hek(entry));
1473 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1478 PERL_ARGS_ASSERT_HV_FREE_ENT;
1482 val = hv_free_ent_ret(hv, entry);
1488 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1492 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1496 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1497 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1498 if (HeKLEN(entry) == HEf_SVKEY) {
1499 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1501 hv_free_ent(hv, entry);
1505 =for apidoc hv_clear
1507 Frees the all the elements of a hash, leaving it empty.
1508 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1510 If any destructors are triggered as a result, the hv itself may
1517 Perl_hv_clear(pTHX_ HV *hv)
1524 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1526 xhv = (XPVHV*)SvANY(hv);
1529 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1530 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1531 /* restricted hash: convert all keys to placeholders */
1533 for (i = 0; i <= xhv->xhv_max; i++) {
1534 HE *entry = (HvARRAY(hv))[i];
1535 for (; entry; entry = HeNEXT(entry)) {
1536 /* not already placeholder */
1537 if (HeVAL(entry) != &PL_sv_placeholder) {
1539 if (SvREADONLY(HeVAL(entry))) {
1540 SV* const keysv = hv_iterkeysv(entry);
1541 Perl_croak_nocontext(
1542 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1545 SvREFCNT_dec_NN(HeVAL(entry));
1547 HeVAL(entry) = &PL_sv_placeholder;
1548 HvPLACEHOLDERS(hv)++;
1555 HvPLACEHOLDERS_set(hv, 0);
1558 mg_clear(MUTABLE_SV(hv));
1560 HvHASKFLAGS_off(hv);
1564 mro_isa_changed_in(hv);
1565 HvEITER_set(hv, NULL);
1571 =for apidoc hv_clear_placeholders
1573 Clears any placeholders from a hash. If a restricted hash has any of its keys
1574 marked as readonly and the key is subsequently deleted, the key is not actually
1575 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1576 it so it will be ignored by future operations such as iterating over the hash,
1577 but will still allow the hash to have a value reassigned to the key at some
1578 future point. This function clears any such placeholder keys from the hash.
1579 See Hash::Util::lock_keys() for an example of its use.
1585 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1588 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1590 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1593 clear_placeholders(hv, items);
1597 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1602 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1609 /* Loop down the linked list heads */
1610 HE **oentry = &(HvARRAY(hv))[i];
1613 while ((entry = *oentry)) {
1614 if (HeVAL(entry) == &PL_sv_placeholder) {
1615 *oentry = HeNEXT(entry);
1616 if (entry == HvEITER_get(hv))
1619 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1620 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1621 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1622 hv_free_ent(hv, entry);
1627 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1628 if (HvUSEDKEYS(hv) == 0)
1629 HvHASKFLAGS_off(hv);
1630 HvPLACEHOLDERS_set(hv, 0);
1634 oentry = &HeNEXT(entry);
1638 /* You can't get here, hence assertion should always fail. */
1639 assert (items == 0);
1644 S_hfreeentries(pTHX_ HV *hv)
1647 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1650 PERL_ARGS_ASSERT_HFREEENTRIES;
1652 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1658 /* hfree_next_entry()
1659 * For use only by S_hfreeentries() and sv_clear().
1660 * Delete the next available HE from hv and return the associated SV.
1661 * Returns null on empty hash. Nevertheless null is not a reliable
1662 * indicator that the hash is empty, as the deleted entry may have a
1664 * indexp is a pointer to the current index into HvARRAY. The index should
1665 * initially be set to 0. hfree_next_entry() may update it. */
1668 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1670 struct xpvhv_aux *iter;
1674 STRLEN orig_index = *indexp;
1677 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1679 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1680 if ((entry = iter->xhv_eiter)) {
1681 /* the iterator may get resurrected after each
1682 * destructor call, so check each time */
1683 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1685 hv_free_ent(hv, entry);
1686 /* warning: at this point HvARRAY may have been
1687 * re-allocated, HvMAX changed etc */
1689 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1690 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1691 #ifdef PERL_HASH_RANDOMIZE_KEYS
1692 iter->xhv_last_rand = iter->xhv_rand;
1695 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1696 will actually call HvFILL() on a hash under destruction, so it
1697 seems pointless attempting to track the number of keys remaining.
1698 But if they do, we want to reset it again. */
1699 if (iter->xhv_fill_lazy)
1700 iter->xhv_fill_lazy = 0;
1703 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1706 array = HvARRAY(hv);
1708 while ( ! ((entry = array[*indexp])) ) {
1709 if ((*indexp)++ >= HvMAX(hv))
1711 assert(*indexp != orig_index);
1713 array[*indexp] = HeNEXT(entry);
1714 ((XPVHV*) SvANY(hv))->xhv_keys--;
1716 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1717 && HeVAL(entry) && isGV(HeVAL(entry))
1718 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1721 const char * const key = HePV(entry,klen);
1722 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1723 || (klen == 1 && key[0] == ':')) {
1725 NULL, GvHV(HeVAL(entry)),
1726 (GV *)HeVAL(entry), 0
1730 return hv_free_ent_ret(hv, entry);
1735 =for apidoc hv_undef
1737 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1739 As well as freeing all the elements of the hash (like hv_clear()), this
1740 also frees any auxiliary data and storage associated with the hash.
1742 If any destructors are triggered as a result, the hv itself may
1745 See also L</hv_clear>.
1751 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1755 const bool save = !!SvREFCNT(hv);
1759 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1760 xhv = (XPVHV*)SvANY(hv);
1762 /* The name must be deleted before the call to hfreeeeentries so that
1763 CVs are anonymised properly. But the effective name must be pre-
1764 served until after that call (and only deleted afterwards if the
1765 call originated from sv_clear). For stashes with one name that is
1766 both the canonical name and the effective name, hv_name_set has to
1767 allocate an array for storing the effective name. We can skip that
1768 during global destruction, as it does not matter where the CVs point
1769 if they will be freed anyway. */
1770 /* note that the code following prior to hfreeentries is duplicated
1771 * in sv_clear(), and changes here should be done there too */
1772 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1773 if (PL_stashcache) {
1774 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1775 HEKf"'\n", HvNAME_HEK(hv)));
1776 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1778 hv_name_set(hv, NULL, 0, 0);
1782 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1786 struct xpvhv_aux * const aux = HvAUX(hv);
1787 struct mro_meta *meta;
1790 if (HvENAME_get(hv)) {
1791 if (PL_phase != PERL_PHASE_DESTRUCT)
1792 mro_isa_changed_in(hv);
1793 if (PL_stashcache) {
1794 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1795 HEKf"'\n", HvENAME_HEK(hv)));
1796 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1800 /* If this call originated from sv_clear, then we must check for
1801 * effective names that need freeing, as well as the usual name. */
1803 if (flags & HV_NAME_SETALL ? !!aux->xhv_name_u.xhvnameu_name : !!name) {
1804 if (name && PL_stashcache) {
1805 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1806 HEKf"'\n", HvNAME_HEK(hv)));
1807 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1809 hv_name_set(hv, NULL, 0, flags);
1811 if((meta = aux->xhv_mro_meta)) {
1812 if (meta->mro_linear_all) {
1813 SvREFCNT_dec_NN(meta->mro_linear_all);
1814 /* mro_linear_current is just acting as a shortcut pointer,
1818 /* Only the current MRO is stored, so this owns the data.
1820 SvREFCNT_dec(meta->mro_linear_current);
1821 SvREFCNT_dec(meta->mro_nextmethod);
1822 SvREFCNT_dec(meta->isa);
1823 SvREFCNT_dec(meta->super);
1825 aux->xhv_mro_meta = NULL;
1827 if (!aux->xhv_name_u.xhvnameu_name && ! aux->xhv_backreferences)
1828 SvFLAGS(hv) &= ~SVf_OOK;
1831 Safefree(HvARRAY(hv));
1832 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1835 /* if we're freeing the HV, the SvMAGIC field has been reused for
1836 * other purposes, and so there can't be any placeholder magic */
1838 HvPLACEHOLDERS_set(hv, 0);
1841 mg_clear(MUTABLE_SV(hv));
1848 Returns the number of hash buckets that happen to be in use. This function is
1849 wrapped by the macro C<HvFILL>.
1851 Previously this value was always stored in the HV structure, which created an
1852 overhead on every hash (and pretty much every object) for something that was
1853 rarely used. Now we calculate it on demand the first time that it is needed,
1854 and cache it if that calculation is going to be costly to repeat. The cached
1855 value is updated by insertions and deletions, but (currently) discarded if
1862 Perl_hv_fill(pTHX_ HV *const hv)
1865 HE **ents = HvARRAY(hv);
1866 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1868 PERL_ARGS_ASSERT_HV_FILL;
1870 /* No keys implies no buckets used.
1871 One key can only possibly mean one bucket used. */
1872 if (HvTOTALKEYS(hv) < 2)
1873 return HvTOTALKEYS(hv);
1876 if (aux && aux->xhv_fill_lazy)
1877 return aux->xhv_fill_lazy;
1881 HE *const *const last = ents + HvMAX(hv);
1882 count = last + 1 - ents;
1887 } while (++ents <= last);
1891 if (aux->xhv_fill_lazy)
1892 assert(aux->xhv_fill_lazy == count);
1894 aux->xhv_fill_lazy = count;
1895 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1896 aux = hv_auxinit(hv);
1897 aux->xhv_fill_lazy = count;
1902 /* hash a pointer to a U32 - Used in the hash traversal randomization
1903 * and bucket order randomization code
1905 * this code was derived from Sereal, which was derived from autobox.
1908 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1911 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1912 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1914 u = (~u) + (u << 18);
1922 * This is one of Bob Jenkins' hash functions for 32-bit integers
1923 * from: http://burtleburtle.net/bob/hash/integer.html
1925 u = (u + 0x7ed55d16) + (u << 12);
1926 u = (u ^ 0xc761c23c) ^ (u >> 19);
1927 u = (u + 0x165667b1) + (u << 5);
1928 u = (u + 0xd3a2646c) ^ (u << 9);
1929 u = (u + 0xfd7046c5) + (u << 3);
1930 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1936 static struct xpvhv_aux*
1937 S_hv_auxinit(pTHX_ HV *hv) {
1938 struct xpvhv_aux *iter;
1941 PERL_ARGS_ASSERT_HV_AUXINIT;
1945 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1946 + sizeof(struct xpvhv_aux), char);
1948 array = (char *) HvARRAY(hv);
1949 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1950 + sizeof(struct xpvhv_aux), char);
1952 HvARRAY(hv) = (HE**)array;
1955 #ifdef PERL_HASH_RANDOMIZE_KEYS
1956 if (PL_HASH_RAND_BITS_ENABLED) {
1957 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
1958 if (PL_HASH_RAND_BITS_ENABLED == 1)
1959 PL_hash_rand_bits += ptr_hash((PTRV)array);
1960 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1962 iter->xhv_rand = (U32)PL_hash_rand_bits;
1968 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1969 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1970 #ifdef PERL_HASH_RANDOMIZE_KEYS
1971 iter->xhv_last_rand = iter->xhv_rand;
1973 iter->xhv_fill_lazy = 0;
1974 iter->xhv_name_u.xhvnameu_name = 0;
1975 iter->xhv_name_count = 0;
1976 iter->xhv_backreferences = 0;
1977 iter->xhv_mro_meta = NULL;
1982 =for apidoc hv_iterinit
1984 Prepares a starting point to traverse a hash table. Returns the number of
1985 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
1986 currently only meaningful for hashes without tie magic.
1988 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1989 hash buckets that happen to be in use. If you still need that esoteric
1990 value, you can get it through the macro C<HvFILL(hv)>.
1997 Perl_hv_iterinit(pTHX_ HV *hv)
1999 PERL_ARGS_ASSERT_HV_ITERINIT;
2001 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
2004 Perl_croak(aTHX_ "Bad hash");
2007 struct xpvhv_aux * const iter = HvAUX(hv);
2008 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2009 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2011 hv_free_ent(hv, entry);
2013 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2014 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2015 #ifdef PERL_HASH_RANDOMIZE_KEYS
2016 iter->xhv_last_rand = iter->xhv_rand;
2022 /* used to be xhv->xhv_fill before 5.004_65 */
2023 return HvTOTALKEYS(hv);
2027 Perl_hv_riter_p(pTHX_ HV *hv) {
2028 struct xpvhv_aux *iter;
2030 PERL_ARGS_ASSERT_HV_RITER_P;
2033 Perl_croak(aTHX_ "Bad hash");
2035 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2036 return &(iter->xhv_riter);
2040 Perl_hv_eiter_p(pTHX_ HV *hv) {
2041 struct xpvhv_aux *iter;
2043 PERL_ARGS_ASSERT_HV_EITER_P;
2046 Perl_croak(aTHX_ "Bad hash");
2048 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2049 return &(iter->xhv_eiter);
2053 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2054 struct xpvhv_aux *iter;
2056 PERL_ARGS_ASSERT_HV_RITER_SET;
2059 Perl_croak(aTHX_ "Bad hash");
2067 iter = hv_auxinit(hv);
2069 iter->xhv_riter = riter;
2073 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2074 struct xpvhv_aux *iter;
2076 PERL_ARGS_ASSERT_HV_RAND_SET;
2078 #ifdef PERL_HASH_RANDOMIZE_KEYS
2080 Perl_croak(aTHX_ "Bad hash");
2085 iter = hv_auxinit(hv);
2087 iter->xhv_rand = new_xhv_rand;
2089 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2094 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2095 struct xpvhv_aux *iter;
2097 PERL_ARGS_ASSERT_HV_EITER_SET;
2100 Perl_croak(aTHX_ "Bad hash");
2105 /* 0 is the default so don't go malloc()ing a new structure just to
2110 iter = hv_auxinit(hv);
2112 iter->xhv_eiter = eiter;
2116 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2119 struct xpvhv_aux *iter;
2123 PERL_ARGS_ASSERT_HV_NAME_SET;
2126 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2130 if (iter->xhv_name_u.xhvnameu_name) {
2131 if(iter->xhv_name_count) {
2132 if(flags & HV_NAME_SETALL) {
2133 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2134 HEK **hekp = name + (
2135 iter->xhv_name_count < 0
2136 ? -iter->xhv_name_count
2137 : iter->xhv_name_count
2139 while(hekp-- > name+1)
2140 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2141 /* The first elem may be null. */
2142 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2144 spot = &iter->xhv_name_u.xhvnameu_name;
2145 iter->xhv_name_count = 0;
2148 if(iter->xhv_name_count > 0) {
2149 /* shift some things over */
2151 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2153 spot = iter->xhv_name_u.xhvnameu_names;
2154 spot[iter->xhv_name_count] = spot[1];
2156 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2158 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2159 unshare_hek_or_pvn(*spot, 0, 0, 0);
2163 else if (flags & HV_NAME_SETALL) {
2164 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2165 spot = &iter->xhv_name_u.xhvnameu_name;
2168 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2169 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2170 iter->xhv_name_count = -2;
2171 spot = iter->xhv_name_u.xhvnameu_names;
2172 spot[1] = existing_name;
2175 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2180 iter = hv_auxinit(hv);
2181 spot = &iter->xhv_name_u.xhvnameu_name;
2183 PERL_HASH(hash, name, len);
2184 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2188 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2193 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2194 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2195 if (flags & SVf_UTF8)
2196 return (bytes_cmp_utf8(
2197 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2198 (const U8*)pv, pvlen) == 0);
2200 return (bytes_cmp_utf8(
2201 (const U8*)pv, pvlen,
2202 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2205 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2206 || memEQ(HEK_KEY(hek), pv, pvlen));
2210 =for apidoc hv_ename_add
2212 Adds a name to a stash's internal list of effective names. See
2215 This is called when a stash is assigned to a new location in the symbol
2222 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2225 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2228 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2231 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2233 PERL_HASH(hash, name, len);
2235 if (aux->xhv_name_count) {
2236 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2237 I32 count = aux->xhv_name_count;
2238 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2239 while (hekp-- > xhv_name)
2241 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2242 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2243 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2245 if (hekp == xhv_name && count < 0)
2246 aux->xhv_name_count = -count;
2249 if (count < 0) aux->xhv_name_count--, count = -count;
2250 else aux->xhv_name_count++;
2251 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2252 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2255 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2258 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2259 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2260 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2263 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2264 aux->xhv_name_count = existing_name ? 2 : -2;
2265 *aux->xhv_name_u.xhvnameu_names = existing_name;
2266 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2271 =for apidoc hv_ename_delete
2273 Removes a name from a stash's internal list of effective names. If this is
2274 the name returned by C<HvENAME>, then another name in the list will take
2275 its place (C<HvENAME> will use it).
2277 This is called when a stash is deleted from the symbol table.
2283 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2286 struct xpvhv_aux *aux;
2288 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2291 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2293 if (!SvOOK(hv)) return;
2296 if (!aux->xhv_name_u.xhvnameu_name) return;
2298 if (aux->xhv_name_count) {
2299 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2300 I32 const count = aux->xhv_name_count;
2301 HEK **victim = namep + (count < 0 ? -count : count);
2302 while (victim-- > namep + 1)
2304 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2305 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2306 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2308 unshare_hek_or_pvn(*victim, 0, 0, 0);
2309 if (count < 0) ++aux->xhv_name_count;
2310 else --aux->xhv_name_count;
2312 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2314 ) { /* if there are none left */
2316 aux->xhv_name_u.xhvnameu_names = NULL;
2317 aux->xhv_name_count = 0;
2320 /* Move the last one back to fill the empty slot. It
2321 does not matter what order they are in. */
2322 *victim = *(namep + (count < 0 ? -count : count) - 1);
2327 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2328 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2329 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2331 aux->xhv_name_count = -count;
2335 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2336 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2337 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2338 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2340 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2341 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2342 *aux->xhv_name_u.xhvnameu_names = namehek;
2343 aux->xhv_name_count = -1;
2348 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2349 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2351 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2352 PERL_UNUSED_CONTEXT;
2354 return &(iter->xhv_backreferences);
2358 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2361 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2366 av = HvAUX(hv)->xhv_backreferences;
2369 HvAUX(hv)->xhv_backreferences = 0;
2370 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2371 if (SvTYPE(av) == SVt_PVAV)
2372 SvREFCNT_dec_NN(av);
2377 hv_iternext is implemented as a macro in hv.h
2379 =for apidoc hv_iternext
2381 Returns entries from a hash iterator. See C<hv_iterinit>.
2383 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2384 iterator currently points to, without losing your place or invalidating your
2385 iterator. Note that in this case the current entry is deleted from the hash
2386 with your iterator holding the last reference to it. Your iterator is flagged
2387 to free the entry on the next call to C<hv_iternext>, so you must not discard
2388 your iterator immediately else the entry will leak - call C<hv_iternext> to
2389 trigger the resource deallocation.
2391 =for apidoc hv_iternext_flags
2393 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2394 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2395 set the placeholders keys (for restricted hashes) will be returned in addition
2396 to normal keys. By default placeholders are automatically skipped over.
2397 Currently a placeholder is implemented with a value that is
2398 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2399 restricted hashes may change, and the implementation currently is
2400 insufficiently abstracted for any change to be tidy.
2406 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2413 struct xpvhv_aux *iter;
2415 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2418 Perl_croak(aTHX_ "Bad hash");
2420 xhv = (XPVHV*)SvANY(hv);
2423 /* Too many things (well, pp_each at least) merrily assume that you can
2424 call hv_iternext without calling hv_iterinit, so we'll have to deal
2430 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2431 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2432 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2433 SV * const key = sv_newmortal();
2435 sv_setsv(key, HeSVKEY_force(entry));
2436 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2437 HeSVKEY_set(entry, NULL);
2443 /* one HE per MAGICAL hash */
2444 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2445 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2447 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2449 HeKEY_hek(entry) = hek;
2450 HeKLEN(entry) = HEf_SVKEY;
2452 magic_nextpack(MUTABLE_SV(hv),mg,key);
2454 /* force key to stay around until next time */
2455 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2456 return entry; /* beware, hent_val is not set */
2458 SvREFCNT_dec(HeVAL(entry));
2459 Safefree(HeKEY_hek(entry));
2461 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2466 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2467 if (!entry && SvRMAGICAL((const SV *)hv)
2468 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2471 /* The prime_env_iter() on VMS just loaded up new hash values
2472 * so the iteration count needs to be reset back to the beginning
2476 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2481 /* hv_iterinit now ensures this. */
2482 assert (HvARRAY(hv));
2484 /* At start of hash, entry is NULL. */
2487 entry = HeNEXT(entry);
2488 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2490 * Skip past any placeholders -- don't want to include them in
2493 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2494 entry = HeNEXT(entry);
2499 #ifdef PERL_HASH_RANDOMIZE_KEYS
2500 if (iter->xhv_last_rand != iter->xhv_rand) {
2501 if (iter->xhv_riter != -1) {
2502 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2503 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2507 iter->xhv_last_rand = iter->xhv_rand;
2511 /* Skip the entire loop if the hash is empty. */
2512 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2513 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2515 /* OK. Come to the end of the current list. Grab the next one. */
2517 iter->xhv_riter++; /* HvRITER(hv)++ */
2518 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2519 /* There is no next one. End of the hash. */
2520 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2521 #ifdef PERL_HASH_RANDOMIZE_KEYS
2522 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2526 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2528 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2529 /* If we have an entry, but it's a placeholder, don't count it.
2531 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2532 entry = HeNEXT(entry);
2534 /* Will loop again if this linked list starts NULL
2535 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2536 or if we run through it and find only placeholders. */
2540 iter->xhv_riter = -1;
2541 #ifdef PERL_HASH_RANDOMIZE_KEYS
2542 iter->xhv_last_rand = iter->xhv_rand;
2546 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2548 hv_free_ent(hv, oldentry);
2551 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2556 =for apidoc hv_iterkey
2558 Returns the key from the current position of the hash iterator. See
2565 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2567 PERL_ARGS_ASSERT_HV_ITERKEY;
2569 if (HeKLEN(entry) == HEf_SVKEY) {
2571 char * const p = SvPV(HeKEY_sv(entry), len);
2576 *retlen = HeKLEN(entry);
2577 return HeKEY(entry);
2581 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2583 =for apidoc hv_iterkeysv
2585 Returns the key as an C<SV*> from the current position of the hash
2586 iterator. The return value will always be a mortal copy of the key. Also
2593 Perl_hv_iterkeysv(pTHX_ HE *entry)
2595 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2597 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2601 =for apidoc hv_iterval
2603 Returns the value from the current position of the hash iterator. See
2610 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2612 PERL_ARGS_ASSERT_HV_ITERVAL;
2614 if (SvRMAGICAL(hv)) {
2615 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2616 SV* const sv = sv_newmortal();
2617 if (HeKLEN(entry) == HEf_SVKEY)
2618 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2620 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2624 return HeVAL(entry);
2628 =for apidoc hv_iternextsv
2630 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2637 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2639 HE * const he = hv_iternext_flags(hv, 0);
2641 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2645 *key = hv_iterkey(he, retlen);
2646 return hv_iterval(hv, he);
2653 =for apidoc hv_magic
2655 Adds magic to a hash. See C<sv_magic>.
2660 /* possibly free a shared string if no one has access to it
2661 * len and hash must both be valid for str.
2664 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2666 unshare_hek_or_pvn (NULL, str, len, hash);
2671 Perl_unshare_hek(pTHX_ HEK *hek)
2674 unshare_hek_or_pvn(hek, NULL, 0, 0);
2677 /* possibly free a shared string if no one has access to it
2678 hek if non-NULL takes priority over the other 3, else str, len and hash
2679 are used. If so, len and hash must both be valid for str.
2682 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2688 bool is_utf8 = FALSE;
2690 const char * const save = str;
2691 struct shared_he *he = NULL;
2694 /* Find the shared he which is just before us in memory. */
2695 he = (struct shared_he *)(((char *)hek)
2696 - STRUCT_OFFSET(struct shared_he,
2699 /* Assert that the caller passed us a genuine (or at least consistent)
2701 assert (he->shared_he_he.hent_hek == hek);
2703 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2704 --he->shared_he_he.he_valu.hent_refcount;
2708 hash = HEK_HASH(hek);
2709 } else if (len < 0) {
2710 STRLEN tmplen = -len;
2712 /* See the note in hv_fetch(). --jhi */
2713 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2716 k_flags = HVhek_UTF8;
2718 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2721 /* what follows was the moral equivalent of:
2722 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2724 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2726 xhv = (XPVHV*)SvANY(PL_strtab);
2727 /* assert(xhv_array != 0) */
2728 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2730 const HE *const he_he = &(he->shared_he_he);
2731 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2736 const int flags_masked = k_flags & HVhek_MASK;
2737 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2738 if (HeHASH(entry) != hash) /* strings can't be equal */
2740 if (HeKLEN(entry) != len)
2742 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2744 if (HeKFLAGS(entry) != flags_masked)
2751 if (--entry->he_valu.hent_refcount == 0) {
2752 *oentry = HeNEXT(entry);
2754 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2759 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2760 "Attempt to free nonexistent shared string '%s'%s"
2762 hek ? HEK_KEY(hek) : str,
2763 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2764 if (k_flags & HVhek_FREEKEY)
2768 /* get a (constant) string ptr from the global string table
2769 * string will get added if it is not already there.
2770 * len and hash must both be valid for str.
2773 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2775 bool is_utf8 = FALSE;
2777 const char * const save = str;
2779 PERL_ARGS_ASSERT_SHARE_HEK;
2782 STRLEN tmplen = -len;
2784 /* See the note in hv_fetch(). --jhi */
2785 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2787 /* If we were able to downgrade here, then than means that we were passed
2788 in a key which only had chars 0-255, but was utf8 encoded. */
2791 /* If we found we were able to downgrade the string to bytes, then
2792 we should flag that it needs upgrading on keys or each. Also flag
2793 that we need share_hek_flags to free the string. */
2796 PERL_HASH(hash, str, len);
2797 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2801 return share_hek_flags (str, len, hash, flags);
2805 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2809 const int flags_masked = flags & HVhek_MASK;
2810 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2811 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2813 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2815 /* what follows is the moral equivalent of:
2817 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2818 hv_store(PL_strtab, str, len, NULL, hash);
2820 Can't rehash the shared string table, so not sure if it's worth
2821 counting the number of entries in the linked list
2824 /* assert(xhv_array != 0) */
2825 entry = (HvARRAY(PL_strtab))[hindex];
2826 for (;entry; entry = HeNEXT(entry)) {
2827 if (HeHASH(entry) != hash) /* strings can't be equal */
2829 if (HeKLEN(entry) != len)
2831 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2833 if (HeKFLAGS(entry) != flags_masked)
2839 /* What used to be head of the list.
2840 If this is NULL, then we're the first entry for this slot, which
2841 means we need to increate fill. */
2842 struct shared_he *new_entry;
2845 HE **const head = &HvARRAY(PL_strtab)[hindex];
2846 HE *const next = *head;
2848 /* We don't actually store a HE from the arena and a regular HEK.
2849 Instead we allocate one chunk of memory big enough for both,
2850 and put the HEK straight after the HE. This way we can find the
2851 HE directly from the HEK.
2854 Newx(k, STRUCT_OFFSET(struct shared_he,
2855 shared_he_hek.hek_key[0]) + len + 2, char);
2856 new_entry = (struct shared_he *)k;
2857 entry = &(new_entry->shared_he_he);
2858 hek = &(new_entry->shared_he_hek);
2860 Copy(str, HEK_KEY(hek), len, char);
2861 HEK_KEY(hek)[len] = 0;
2863 HEK_HASH(hek) = hash;
2864 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2866 /* Still "point" to the HEK, so that other code need not know what
2868 HeKEY_hek(entry) = hek;
2869 entry->he_valu.hent_refcount = 0;
2870 HeNEXT(entry) = next;
2873 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2874 if (!next) { /* initial entry? */
2875 } else if ( DO_HSPLIT(xhv) ) {
2876 const STRLEN oldsize = xhv->xhv_max + 1;
2877 hsplit(PL_strtab, oldsize, oldsize * 2);
2881 ++entry->he_valu.hent_refcount;
2883 if (flags & HVhek_FREEKEY)
2886 return HeKEY_hek(entry);
2890 Perl_hv_placeholders_p(pTHX_ HV *hv)
2893 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2895 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2898 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2901 Perl_die(aTHX_ "panic: hv_placeholders_p");
2904 return &(mg->mg_len);
2909 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2912 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2914 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2916 return mg ? mg->mg_len : 0;
2920 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2923 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2925 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2930 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2931 Perl_die(aTHX_ "panic: hv_placeholders_set");
2933 /* else we don't need to add magic to record 0 placeholders. */
2937 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2942 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2944 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2949 value = &PL_sv_placeholder;
2952 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2955 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2958 case HVrhek_PV_UTF8:
2959 /* Create a string SV that directly points to the bytes in our
2961 value = newSV_type(SVt_PV);
2962 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2963 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2964 /* This stops anything trying to free it */
2965 SvLEN_set(value, 0);
2967 SvREADONLY_on(value);
2968 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2972 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2973 (UV)he->refcounted_he_data[0]);
2979 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2981 Generates and returns a C<HV *> representing the content of a
2982 C<refcounted_he> chain.
2983 I<flags> is currently unused and must be zero.
2988 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2992 U32 placeholders, max;
2995 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
2998 /* We could chase the chain once to get an idea of the number of keys,
2999 and call ksplit. But for now we'll make a potentially inefficient
3000 hash with only 8 entries in its array. */
3005 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3006 HvARRAY(hv) = (HE**)array;
3012 U32 hash = chain->refcounted_he_hash;
3014 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3016 HE **oentry = &((HvARRAY(hv))[hash & max]);
3017 HE *entry = *oentry;
3020 for (; entry; entry = HeNEXT(entry)) {
3021 if (HeHASH(entry) == hash) {
3022 /* We might have a duplicate key here. If so, entry is older
3023 than the key we've already put in the hash, so if they are
3024 the same, skip adding entry. */
3026 const STRLEN klen = HeKLEN(entry);
3027 const char *const key = HeKEY(entry);
3028 if (klen == chain->refcounted_he_keylen
3029 && (!!HeKUTF8(entry)
3030 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3031 && memEQ(key, REF_HE_KEY(chain), klen))
3034 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3036 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3037 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3038 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3049 = share_hek_flags(REF_HE_KEY(chain),
3050 chain->refcounted_he_keylen,
3051 chain->refcounted_he_hash,
3052 (chain->refcounted_he_data[0]
3053 & (HVhek_UTF8|HVhek_WASUTF8)));
3055 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3057 value = refcounted_he_value(chain);
3058 if (value == &PL_sv_placeholder)
3060 HeVAL(entry) = value;
3062 /* Link it into the chain. */
3063 HeNEXT(entry) = *oentry;
3069 chain = chain->refcounted_he_next;
3073 clear_placeholders(hv, placeholders);
3074 HvTOTALKEYS(hv) -= placeholders;
3077 /* We could check in the loop to see if we encounter any keys with key
3078 flags, but it's probably not worth it, as this per-hash flag is only
3079 really meant as an optimisation for things like Storable. */
3081 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3087 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3089 Search along a C<refcounted_he> chain for an entry with the key specified
3090 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3091 bit set, the key octets are interpreted as UTF-8, otherwise they
3092 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3093 string, or zero if it has not been precomputed. Returns a mortal scalar
3094 representing the value associated with the key, or C<&PL_sv_placeholder>
3095 if there is no value associated with the key.
3101 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3102 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3106 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3108 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3109 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3112 return &PL_sv_placeholder;
3113 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3114 /* For searching purposes, canonicalise to Latin-1 where possible. */
3115 const char *keyend = keypv + keylen, *p;
3116 STRLEN nonascii_count = 0;
3117 for (p = keypv; p != keyend; p++) {
3118 if (! UTF8_IS_INVARIANT(*p)) {
3119 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3120 goto canonicalised_key;
3126 if (nonascii_count) {
3128 const char *p = keypv, *keyend = keypv + keylen;
3129 keylen -= nonascii_count;
3130 Newx(q, keylen, char);
3133 for (; p != keyend; p++, q++) {
3135 if (UTF8_IS_INVARIANT(c)) {
3140 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3144 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3145 canonicalised_key: ;
3147 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3149 PERL_HASH(hash, keypv, keylen);
3151 for (; chain; chain = chain->refcounted_he_next) {
3154 hash == chain->refcounted_he_hash &&
3155 keylen == chain->refcounted_he_keylen &&
3156 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3157 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3159 hash == HEK_HASH(chain->refcounted_he_hek) &&
3160 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3161 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3162 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3165 if (flags & REFCOUNTED_HE_EXISTS)
3166 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3168 ? NULL : &PL_sv_yes;
3169 return sv_2mortal(refcounted_he_value(chain));
3172 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3176 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3178 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3179 instead of a string/length pair.
3185 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3186 const char *key, U32 hash, U32 flags)
3188 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3189 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3193 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3195 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3202 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3203 SV *key, U32 hash, U32 flags)
3207 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3208 if (flags & REFCOUNTED_HE_KEY_UTF8)
3209 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3211 keypv = SvPV_const(key, keylen);
3213 flags |= REFCOUNTED_HE_KEY_UTF8;
3214 if (!hash && SvIsCOW_shared_hash(key))
3215 hash = SvSHARED_HASH(key);
3216 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3220 =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
3222 Creates a new C<refcounted_he>. This consists of a single key/value
3223 pair and a reference to an existing C<refcounted_he> chain (which may
3224 be empty), and thus forms a longer chain. When using the longer chain,
3225 the new key/value pair takes precedence over any entry for the same key
3226 further along the chain.
3228 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3229 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3230 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3231 a precomputed hash of the key string, or zero if it has not been
3234 I<value> is the scalar value to store for this key. I<value> is copied
3235 by this function, which thus does not take ownership of any reference
3236 to it, and later changes to the scalar will not be reflected in the
3237 value visible in the C<refcounted_he>. Complex types of scalar will not
3238 be stored with referential integrity, but will be coerced to strings.
3239 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3240 value is to be associated with the key; this, as with any non-null value,
3241 takes precedence over the existence of a value for the key further along
3244 I<parent> points to the rest of the C<refcounted_he> chain to be
3245 attached to the new C<refcounted_he>. This function takes ownership
3246 of one reference to I<parent>, and returns one reference to the new
3252 struct refcounted_he *
3253 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3254 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3257 STRLEN value_len = 0;
3258 const char *value_p = NULL;
3262 STRLEN key_offset = 1;
3263 struct refcounted_he *he;
3264 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3266 if (!value || value == &PL_sv_placeholder) {
3267 value_type = HVrhek_delete;
3268 } else if (SvPOK(value)) {
3269 value_type = HVrhek_PV;
3270 } else if (SvIOK(value)) {
3271 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3272 } else if (!SvOK(value)) {
3273 value_type = HVrhek_undef;
3275 value_type = HVrhek_PV;
3277 is_pv = value_type == HVrhek_PV;
3279 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3280 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3281 value_p = SvPV_const(value, value_len);
3283 value_type = HVrhek_PV_UTF8;
3284 key_offset = value_len + 2;
3286 hekflags = value_type;
3288 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3289 /* Canonicalise to Latin-1 where possible. */
3290 const char *keyend = keypv + keylen, *p;
3291 STRLEN nonascii_count = 0;
3292 for (p = keypv; p != keyend; p++) {
3293 if (! UTF8_IS_INVARIANT(*p)) {
3294 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3295 goto canonicalised_key;
3301 if (nonascii_count) {
3303 const char *p = keypv, *keyend = keypv + keylen;
3304 keylen -= nonascii_count;
3305 Newx(q, keylen, char);
3308 for (; p != keyend; p++, q++) {
3310 if (UTF8_IS_INVARIANT(c)) {
3315 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3319 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3320 canonicalised_key: ;
3322 if (flags & REFCOUNTED_HE_KEY_UTF8)
3323 hekflags |= HVhek_UTF8;
3325 PERL_HASH(hash, keypv, keylen);
3328 he = (struct refcounted_he*)
3329 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3333 he = (struct refcounted_he*)
3334 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3338 he->refcounted_he_next = parent;
3341 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3342 he->refcounted_he_val.refcounted_he_u_len = value_len;
3343 } else if (value_type == HVrhek_IV) {
3344 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3345 } else if (value_type == HVrhek_UV) {
3346 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3350 he->refcounted_he_hash = hash;
3351 he->refcounted_he_keylen = keylen;
3352 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3354 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3357 he->refcounted_he_data[0] = hekflags;
3358 he->refcounted_he_refcnt = 1;
3364 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3366 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3367 of a string/length pair.
3372 struct refcounted_he *
3373 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3374 const char *key, U32 hash, SV *value, U32 flags)
3376 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3377 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3381 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3383 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3389 struct refcounted_he *
3390 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3391 SV *key, U32 hash, SV *value, U32 flags)
3395 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3396 if (flags & REFCOUNTED_HE_KEY_UTF8)
3397 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3399 keypv = SvPV_const(key, keylen);
3401 flags |= REFCOUNTED_HE_KEY_UTF8;
3402 if (!hash && SvIsCOW_shared_hash(key))
3403 hash = SvSHARED_HASH(key);
3404 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3408 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3410 Decrements the reference count of a C<refcounted_he> by one. If the
3411 reference count reaches zero the structure's memory is freed, which
3412 (recursively) causes a reduction of its parent C<refcounted_he>'s
3413 reference count. It is safe to pass a null pointer to this function:
3414 no action occurs in this case.
3420 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3422 PERL_UNUSED_CONTEXT;
3425 struct refcounted_he *copy;
3429 new_count = --he->refcounted_he_refcnt;
3430 HINTS_REFCNT_UNLOCK;
3436 #ifndef USE_ITHREADS
3437 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3440 he = he->refcounted_he_next;
3441 PerlMemShared_free(copy);
3446 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3448 Increment the reference count of a C<refcounted_he>. The pointer to the
3449 C<refcounted_he> is also returned. It is safe to pass a null pointer
3450 to this function: no action occurs and a null pointer is returned.
3455 struct refcounted_he *
3456 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3461 he->refcounted_he_refcnt++;
3462 HINTS_REFCNT_UNLOCK;
3468 =for apidoc cop_fetch_label
3470 Returns the label attached to a cop.
3471 The flags pointer may be set to C<SVf_UTF8> or 0.
3476 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3479 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3480 struct refcounted_he *const chain = cop->cop_hints_hash;
3482 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3487 if (chain->refcounted_he_keylen != 1)
3489 if (*REF_HE_KEY(chain) != ':')
3492 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3494 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3497 /* Stop anyone trying to really mess us up by adding their own value for
3499 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3500 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3504 *len = chain->refcounted_he_val.refcounted_he_u_len;
3506 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3507 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3509 return chain->refcounted_he_data + 1;
3513 =for apidoc cop_store_label
3515 Save a label into a C<cop_hints_hash>. You need to set flags to C<SVf_UTF8>
3522 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3526 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3528 if (flags & ~(SVf_UTF8))
3529 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3531 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3532 if (flags & SVf_UTF8)
3535 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3539 =for apidoc hv_assert
3541 Check that a hash is in an internally consistent state.
3549 Perl_hv_assert(pTHX_ HV *hv)
3554 int placeholders = 0;
3557 const I32 riter = HvRITER_get(hv);
3558 HE *eiter = HvEITER_get(hv);
3560 PERL_ARGS_ASSERT_HV_ASSERT;
3562 (void)hv_iterinit(hv);
3564 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3565 /* sanity check the values */
3566 if (HeVAL(entry) == &PL_sv_placeholder)
3570 /* sanity check the keys */
3571 if (HeSVKEY(entry)) {
3572 NOOP; /* Don't know what to check on SV keys. */
3573 } else if (HeKUTF8(entry)) {
3575 if (HeKWASUTF8(entry)) {
3576 PerlIO_printf(Perl_debug_log,
3577 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3578 (int) HeKLEN(entry), HeKEY(entry));
3581 } else if (HeKWASUTF8(entry))
3584 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3585 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3586 const int nhashkeys = HvUSEDKEYS(hv);
3587 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3589 if (nhashkeys != real) {
3590 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3593 if (nhashplaceholders != placeholders) {
3594 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3598 if (withflags && ! HvHASKFLAGS(hv)) {
3599 PerlIO_printf(Perl_debug_log,
3600 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3605 sv_dump(MUTABLE_SV(hv));
3607 HvRITER_set(hv, riter); /* Restore hash iterator state */
3608 HvEITER_set(hv, eiter);
3615 * c-indentation-style: bsd
3617 * indent-tabs-mode: nil
3620 * ex: set ts=8 sts=4 sw=4 et: