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)
1756 const bool save = !!SvREFCNT(hv);
1760 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1761 xhv = (XPVHV*)SvANY(hv);
1763 /* The name must be deleted before the call to hfreeeeentries so that
1764 CVs are anonymised properly. But the effective name must be pre-
1765 served until after that call (and only deleted afterwards if the
1766 call originated from sv_clear). For stashes with one name that is
1767 both the canonical name and the effective name, hv_name_set has to
1768 allocate an array for storing the effective name. We can skip that
1769 during global destruction, as it does not matter where the CVs point
1770 if they will be freed anyway. */
1771 /* note that the code following prior to hfreeentries is duplicated
1772 * in sv_clear(), and changes here should be done there too */
1773 if (PL_phase != PERL_PHASE_DESTRUCT && (name = HvNAME(hv))) {
1774 if (PL_stashcache) {
1775 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1776 HEKf"'\n", HvNAME_HEK(hv)));
1777 (void)hv_delete(PL_stashcache, name,
1778 HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv),
1782 hv_name_set(hv, NULL, 0, 0);
1786 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1790 struct xpvhv_aux * const aux = HvAUX(hv);
1791 struct mro_meta *meta;
1793 if ((name = HvENAME_get(hv))) {
1794 if (PL_phase != PERL_PHASE_DESTRUCT)
1795 mro_isa_changed_in(hv);
1796 if (PL_stashcache) {
1797 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1798 HEKf"'\n", HvENAME_HEK(hv)));
1800 PL_stashcache, name,
1801 HEK_UTF8(HvENAME_HEK(hv)) ? -HvENAMELEN_get(hv) : HvENAMELEN_get(hv),
1807 /* If this call originated from sv_clear, then we must check for
1808 * effective names that need freeing, as well as the usual name. */
1810 if (flags & HV_NAME_SETALL ? !!aux->xhv_name_u.xhvnameu_name : !!name) {
1811 if (name && PL_stashcache) {
1812 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1813 HEKf"'\n", HvNAME_HEK(hv)));
1814 (void)hv_delete(PL_stashcache, name, (HEK_UTF8(HvNAME_HEK(hv)) ? -HvNAMELEN_get(hv) : HvNAMELEN_get(hv)), G_DISCARD);
1816 hv_name_set(hv, NULL, 0, flags);
1818 if((meta = aux->xhv_mro_meta)) {
1819 if (meta->mro_linear_all) {
1820 SvREFCNT_dec_NN(meta->mro_linear_all);
1821 /* mro_linear_current is just acting as a shortcut pointer,
1825 /* Only the current MRO is stored, so this owns the data.
1827 SvREFCNT_dec(meta->mro_linear_current);
1828 SvREFCNT_dec(meta->mro_nextmethod);
1829 SvREFCNT_dec(meta->isa);
1830 SvREFCNT_dec(meta->super);
1832 aux->xhv_mro_meta = NULL;
1834 if (!aux->xhv_name_u.xhvnameu_name && ! aux->xhv_backreferences)
1835 SvFLAGS(hv) &= ~SVf_OOK;
1838 Safefree(HvARRAY(hv));
1839 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1842 /* if we're freeing the HV, the SvMAGIC field has been reused for
1843 * other purposes, and so there can't be any placeholder magic */
1845 HvPLACEHOLDERS_set(hv, 0);
1848 mg_clear(MUTABLE_SV(hv));
1855 Returns the number of hash buckets that happen to be in use. This function is
1856 wrapped by the macro C<HvFILL>.
1858 Previously this value was always stored in the HV structure, which created an
1859 overhead on every hash (and pretty much every object) for something that was
1860 rarely used. Now we calculate it on demand the first time that it is needed,
1861 and cache it if that calculation is going to be costly to repeat. The cached
1862 value is updated by insertions and deletions, but (currently) discarded if
1869 Perl_hv_fill(pTHX_ HV *const hv)
1872 HE **ents = HvARRAY(hv);
1873 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1875 PERL_ARGS_ASSERT_HV_FILL;
1877 /* No keys implies no buckets used.
1878 One key can only possibly mean one bucket used. */
1879 if (HvTOTALKEYS(hv) < 2)
1880 return HvTOTALKEYS(hv);
1883 if (aux && aux->xhv_fill_lazy)
1884 return aux->xhv_fill_lazy;
1888 HE *const *const last = ents + HvMAX(hv);
1889 count = last + 1 - ents;
1894 } while (++ents <= last);
1898 if (aux->xhv_fill_lazy)
1899 assert(aux->xhv_fill_lazy == count);
1901 aux->xhv_fill_lazy = count;
1902 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1903 aux = hv_auxinit(hv);
1904 aux->xhv_fill_lazy = count;
1909 /* hash a pointer to a U32 - Used in the hash traversal randomization
1910 * and bucket order randomization code
1912 * this code was derived from Sereal, which was derived from autobox.
1915 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1918 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1919 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1921 u = (~u) + (u << 18);
1929 * This is one of Bob Jenkins' hash functions for 32-bit integers
1930 * from: http://burtleburtle.net/bob/hash/integer.html
1932 u = (u + 0x7ed55d16) + (u << 12);
1933 u = (u ^ 0xc761c23c) ^ (u >> 19);
1934 u = (u + 0x165667b1) + (u << 5);
1935 u = (u + 0xd3a2646c) ^ (u << 9);
1936 u = (u + 0xfd7046c5) + (u << 3);
1937 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1943 static struct xpvhv_aux*
1944 S_hv_auxinit(pTHX_ HV *hv) {
1945 struct xpvhv_aux *iter;
1948 PERL_ARGS_ASSERT_HV_AUXINIT;
1952 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1953 + sizeof(struct xpvhv_aux), char);
1955 array = (char *) HvARRAY(hv);
1956 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1957 + sizeof(struct xpvhv_aux), char);
1959 HvARRAY(hv) = (HE**)array;
1962 #ifdef PERL_HASH_RANDOMIZE_KEYS
1963 if (PL_HASH_RAND_BITS_ENABLED) {
1964 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
1965 if (PL_HASH_RAND_BITS_ENABLED == 1)
1966 PL_hash_rand_bits += ptr_hash((PTRV)array);
1967 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1969 iter->xhv_rand = (U32)PL_hash_rand_bits;
1975 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1976 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1977 #ifdef PERL_HASH_RANDOMIZE_KEYS
1978 iter->xhv_last_rand = iter->xhv_rand;
1980 iter->xhv_fill_lazy = 0;
1981 iter->xhv_name_u.xhvnameu_name = 0;
1982 iter->xhv_name_count = 0;
1983 iter->xhv_backreferences = 0;
1984 iter->xhv_mro_meta = NULL;
1989 =for apidoc hv_iterinit
1991 Prepares a starting point to traverse a hash table. Returns the number of
1992 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
1993 currently only meaningful for hashes without tie magic.
1995 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1996 hash buckets that happen to be in use. If you still need that esoteric
1997 value, you can get it through the macro C<HvFILL(hv)>.
2004 Perl_hv_iterinit(pTHX_ HV *hv)
2006 PERL_ARGS_ASSERT_HV_ITERINIT;
2008 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
2011 Perl_croak(aTHX_ "Bad hash");
2014 struct xpvhv_aux * const iter = HvAUX(hv);
2015 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2016 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2018 hv_free_ent(hv, entry);
2020 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2021 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2022 #ifdef PERL_HASH_RANDOMIZE_KEYS
2023 iter->xhv_last_rand = iter->xhv_rand;
2029 /* used to be xhv->xhv_fill before 5.004_65 */
2030 return HvTOTALKEYS(hv);
2034 Perl_hv_riter_p(pTHX_ HV *hv) {
2035 struct xpvhv_aux *iter;
2037 PERL_ARGS_ASSERT_HV_RITER_P;
2040 Perl_croak(aTHX_ "Bad hash");
2042 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2043 return &(iter->xhv_riter);
2047 Perl_hv_eiter_p(pTHX_ HV *hv) {
2048 struct xpvhv_aux *iter;
2050 PERL_ARGS_ASSERT_HV_EITER_P;
2053 Perl_croak(aTHX_ "Bad hash");
2055 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2056 return &(iter->xhv_eiter);
2060 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2061 struct xpvhv_aux *iter;
2063 PERL_ARGS_ASSERT_HV_RITER_SET;
2066 Perl_croak(aTHX_ "Bad hash");
2074 iter = hv_auxinit(hv);
2076 iter->xhv_riter = riter;
2080 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2081 struct xpvhv_aux *iter;
2083 PERL_ARGS_ASSERT_HV_RAND_SET;
2085 #ifdef PERL_HASH_RANDOMIZE_KEYS
2087 Perl_croak(aTHX_ "Bad hash");
2092 iter = hv_auxinit(hv);
2094 iter->xhv_rand = new_xhv_rand;
2096 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2101 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2102 struct xpvhv_aux *iter;
2104 PERL_ARGS_ASSERT_HV_EITER_SET;
2107 Perl_croak(aTHX_ "Bad hash");
2112 /* 0 is the default so don't go malloc()ing a new structure just to
2117 iter = hv_auxinit(hv);
2119 iter->xhv_eiter = eiter;
2123 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2126 struct xpvhv_aux *iter;
2130 PERL_ARGS_ASSERT_HV_NAME_SET;
2133 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2137 if (iter->xhv_name_u.xhvnameu_name) {
2138 if(iter->xhv_name_count) {
2139 if(flags & HV_NAME_SETALL) {
2140 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2141 HEK **hekp = name + (
2142 iter->xhv_name_count < 0
2143 ? -iter->xhv_name_count
2144 : iter->xhv_name_count
2146 while(hekp-- > name+1)
2147 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2148 /* The first elem may be null. */
2149 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2151 spot = &iter->xhv_name_u.xhvnameu_name;
2152 iter->xhv_name_count = 0;
2155 if(iter->xhv_name_count > 0) {
2156 /* shift some things over */
2158 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2160 spot = iter->xhv_name_u.xhvnameu_names;
2161 spot[iter->xhv_name_count] = spot[1];
2163 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2165 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2166 unshare_hek_or_pvn(*spot, 0, 0, 0);
2170 else if (flags & HV_NAME_SETALL) {
2171 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2172 spot = &iter->xhv_name_u.xhvnameu_name;
2175 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2176 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2177 iter->xhv_name_count = -2;
2178 spot = iter->xhv_name_u.xhvnameu_names;
2179 spot[1] = existing_name;
2182 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2187 iter = hv_auxinit(hv);
2188 spot = &iter->xhv_name_u.xhvnameu_name;
2190 PERL_HASH(hash, name, len);
2191 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2195 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2200 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2201 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2202 if (flags & SVf_UTF8)
2203 return (bytes_cmp_utf8(
2204 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2205 (const U8*)pv, pvlen) == 0);
2207 return (bytes_cmp_utf8(
2208 (const U8*)pv, pvlen,
2209 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2212 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2213 || memEQ(HEK_KEY(hek), pv, pvlen));
2217 =for apidoc hv_ename_add
2219 Adds a name to a stash's internal list of effective names. See
2222 This is called when a stash is assigned to a new location in the symbol
2229 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2232 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2235 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2238 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2240 PERL_HASH(hash, name, len);
2242 if (aux->xhv_name_count) {
2243 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2244 I32 count = aux->xhv_name_count;
2245 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2246 while (hekp-- > xhv_name)
2248 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2249 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2250 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2252 if (hekp == xhv_name && count < 0)
2253 aux->xhv_name_count = -count;
2256 if (count < 0) aux->xhv_name_count--, count = -count;
2257 else aux->xhv_name_count++;
2258 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2259 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2262 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2265 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2266 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2267 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2270 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2271 aux->xhv_name_count = existing_name ? 2 : -2;
2272 *aux->xhv_name_u.xhvnameu_names = existing_name;
2273 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2278 =for apidoc hv_ename_delete
2280 Removes a name from a stash's internal list of effective names. If this is
2281 the name returned by C<HvENAME>, then another name in the list will take
2282 its place (C<HvENAME> will use it).
2284 This is called when a stash is deleted from the symbol table.
2290 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2293 struct xpvhv_aux *aux;
2295 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2298 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2300 if (!SvOOK(hv)) return;
2303 if (!aux->xhv_name_u.xhvnameu_name) return;
2305 if (aux->xhv_name_count) {
2306 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2307 I32 const count = aux->xhv_name_count;
2308 HEK **victim = namep + (count < 0 ? -count : count);
2309 while (victim-- > namep + 1)
2311 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2312 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2313 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2315 unshare_hek_or_pvn(*victim, 0, 0, 0);
2316 if (count < 0) ++aux->xhv_name_count;
2317 else --aux->xhv_name_count;
2319 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2321 ) { /* if there are none left */
2323 aux->xhv_name_u.xhvnameu_names = NULL;
2324 aux->xhv_name_count = 0;
2327 /* Move the last one back to fill the empty slot. It
2328 does not matter what order they are in. */
2329 *victim = *(namep + (count < 0 ? -count : count) - 1);
2334 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2335 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2336 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2338 aux->xhv_name_count = -count;
2342 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2343 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2344 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2345 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2347 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2348 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2349 *aux->xhv_name_u.xhvnameu_names = namehek;
2350 aux->xhv_name_count = -1;
2355 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2356 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2358 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2359 PERL_UNUSED_CONTEXT;
2361 return &(iter->xhv_backreferences);
2365 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2368 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2373 av = HvAUX(hv)->xhv_backreferences;
2376 HvAUX(hv)->xhv_backreferences = 0;
2377 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2378 if (SvTYPE(av) == SVt_PVAV)
2379 SvREFCNT_dec_NN(av);
2384 hv_iternext is implemented as a macro in hv.h
2386 =for apidoc hv_iternext
2388 Returns entries from a hash iterator. See C<hv_iterinit>.
2390 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2391 iterator currently points to, without losing your place or invalidating your
2392 iterator. Note that in this case the current entry is deleted from the hash
2393 with your iterator holding the last reference to it. Your iterator is flagged
2394 to free the entry on the next call to C<hv_iternext>, so you must not discard
2395 your iterator immediately else the entry will leak - call C<hv_iternext> to
2396 trigger the resource deallocation.
2398 =for apidoc hv_iternext_flags
2400 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2401 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2402 set the placeholders keys (for restricted hashes) will be returned in addition
2403 to normal keys. By default placeholders are automatically skipped over.
2404 Currently a placeholder is implemented with a value that is
2405 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2406 restricted hashes may change, and the implementation currently is
2407 insufficiently abstracted for any change to be tidy.
2413 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2420 struct xpvhv_aux *iter;
2422 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2425 Perl_croak(aTHX_ "Bad hash");
2427 xhv = (XPVHV*)SvANY(hv);
2430 /* Too many things (well, pp_each at least) merrily assume that you can
2431 call hv_iternext without calling hv_iterinit, so we'll have to deal
2437 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2438 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2439 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2440 SV * const key = sv_newmortal();
2442 sv_setsv(key, HeSVKEY_force(entry));
2443 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2444 HeSVKEY_set(entry, NULL);
2450 /* one HE per MAGICAL hash */
2451 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2452 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2454 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2456 HeKEY_hek(entry) = hek;
2457 HeKLEN(entry) = HEf_SVKEY;
2459 magic_nextpack(MUTABLE_SV(hv),mg,key);
2461 /* force key to stay around until next time */
2462 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2463 return entry; /* beware, hent_val is not set */
2465 SvREFCNT_dec(HeVAL(entry));
2466 Safefree(HeKEY_hek(entry));
2468 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2473 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2474 if (!entry && SvRMAGICAL((const SV *)hv)
2475 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2478 /* The prime_env_iter() on VMS just loaded up new hash values
2479 * so the iteration count needs to be reset back to the beginning
2483 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2488 /* hv_iterinit now ensures this. */
2489 assert (HvARRAY(hv));
2491 /* At start of hash, entry is NULL. */
2494 entry = HeNEXT(entry);
2495 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2497 * Skip past any placeholders -- don't want to include them in
2500 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2501 entry = HeNEXT(entry);
2506 #ifdef PERL_HASH_RANDOMIZE_KEYS
2507 if (iter->xhv_last_rand != iter->xhv_rand) {
2508 if (iter->xhv_riter != -1) {
2509 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2510 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2514 iter->xhv_last_rand = iter->xhv_rand;
2518 /* Skip the entire loop if the hash is empty. */
2519 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2520 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2522 /* OK. Come to the end of the current list. Grab the next one. */
2524 iter->xhv_riter++; /* HvRITER(hv)++ */
2525 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2526 /* There is no next one. End of the hash. */
2527 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2528 #ifdef PERL_HASH_RANDOMIZE_KEYS
2529 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2533 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2535 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2536 /* If we have an entry, but it's a placeholder, don't count it.
2538 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2539 entry = HeNEXT(entry);
2541 /* Will loop again if this linked list starts NULL
2542 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2543 or if we run through it and find only placeholders. */
2547 iter->xhv_riter = -1;
2548 #ifdef PERL_HASH_RANDOMIZE_KEYS
2549 iter->xhv_last_rand = iter->xhv_rand;
2553 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2555 hv_free_ent(hv, oldentry);
2558 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2563 =for apidoc hv_iterkey
2565 Returns the key from the current position of the hash iterator. See
2572 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2574 PERL_ARGS_ASSERT_HV_ITERKEY;
2576 if (HeKLEN(entry) == HEf_SVKEY) {
2578 char * const p = SvPV(HeKEY_sv(entry), len);
2583 *retlen = HeKLEN(entry);
2584 return HeKEY(entry);
2588 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2590 =for apidoc hv_iterkeysv
2592 Returns the key as an C<SV*> from the current position of the hash
2593 iterator. The return value will always be a mortal copy of the key. Also
2600 Perl_hv_iterkeysv(pTHX_ HE *entry)
2602 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2604 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2608 =for apidoc hv_iterval
2610 Returns the value from the current position of the hash iterator. See
2617 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2619 PERL_ARGS_ASSERT_HV_ITERVAL;
2621 if (SvRMAGICAL(hv)) {
2622 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2623 SV* const sv = sv_newmortal();
2624 if (HeKLEN(entry) == HEf_SVKEY)
2625 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2627 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2631 return HeVAL(entry);
2635 =for apidoc hv_iternextsv
2637 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2644 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2646 HE * const he = hv_iternext_flags(hv, 0);
2648 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2652 *key = hv_iterkey(he, retlen);
2653 return hv_iterval(hv, he);
2660 =for apidoc hv_magic
2662 Adds magic to a hash. See C<sv_magic>.
2667 /* possibly free a shared string if no one has access to it
2668 * len and hash must both be valid for str.
2671 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2673 unshare_hek_or_pvn (NULL, str, len, hash);
2678 Perl_unshare_hek(pTHX_ HEK *hek)
2681 unshare_hek_or_pvn(hek, NULL, 0, 0);
2684 /* possibly free a shared string if no one has access to it
2685 hek if non-NULL takes priority over the other 3, else str, len and hash
2686 are used. If so, len and hash must both be valid for str.
2689 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2695 bool is_utf8 = FALSE;
2697 const char * const save = str;
2698 struct shared_he *he = NULL;
2701 /* Find the shared he which is just before us in memory. */
2702 he = (struct shared_he *)(((char *)hek)
2703 - STRUCT_OFFSET(struct shared_he,
2706 /* Assert that the caller passed us a genuine (or at least consistent)
2708 assert (he->shared_he_he.hent_hek == hek);
2710 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2711 --he->shared_he_he.he_valu.hent_refcount;
2715 hash = HEK_HASH(hek);
2716 } else if (len < 0) {
2717 STRLEN tmplen = -len;
2719 /* See the note in hv_fetch(). --jhi */
2720 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2723 k_flags = HVhek_UTF8;
2725 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2728 /* what follows was the moral equivalent of:
2729 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2731 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2733 xhv = (XPVHV*)SvANY(PL_strtab);
2734 /* assert(xhv_array != 0) */
2735 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2737 const HE *const he_he = &(he->shared_he_he);
2738 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2743 const int flags_masked = k_flags & HVhek_MASK;
2744 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2745 if (HeHASH(entry) != hash) /* strings can't be equal */
2747 if (HeKLEN(entry) != len)
2749 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2751 if (HeKFLAGS(entry) != flags_masked)
2758 if (--entry->he_valu.hent_refcount == 0) {
2759 *oentry = HeNEXT(entry);
2761 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2766 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2767 "Attempt to free nonexistent shared string '%s'%s"
2769 hek ? HEK_KEY(hek) : str,
2770 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2771 if (k_flags & HVhek_FREEKEY)
2775 /* get a (constant) string ptr from the global string table
2776 * string will get added if it is not already there.
2777 * len and hash must both be valid for str.
2780 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2782 bool is_utf8 = FALSE;
2784 const char * const save = str;
2786 PERL_ARGS_ASSERT_SHARE_HEK;
2789 STRLEN tmplen = -len;
2791 /* See the note in hv_fetch(). --jhi */
2792 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2794 /* If we were able to downgrade here, then than means that we were passed
2795 in a key which only had chars 0-255, but was utf8 encoded. */
2798 /* If we found we were able to downgrade the string to bytes, then
2799 we should flag that it needs upgrading on keys or each. Also flag
2800 that we need share_hek_flags to free the string. */
2803 PERL_HASH(hash, str, len);
2804 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2808 return share_hek_flags (str, len, hash, flags);
2812 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2816 const int flags_masked = flags & HVhek_MASK;
2817 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2818 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2820 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2822 /* what follows is the moral equivalent of:
2824 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2825 hv_store(PL_strtab, str, len, NULL, hash);
2827 Can't rehash the shared string table, so not sure if it's worth
2828 counting the number of entries in the linked list
2831 /* assert(xhv_array != 0) */
2832 entry = (HvARRAY(PL_strtab))[hindex];
2833 for (;entry; entry = HeNEXT(entry)) {
2834 if (HeHASH(entry) != hash) /* strings can't be equal */
2836 if (HeKLEN(entry) != len)
2838 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2840 if (HeKFLAGS(entry) != flags_masked)
2846 /* What used to be head of the list.
2847 If this is NULL, then we're the first entry for this slot, which
2848 means we need to increate fill. */
2849 struct shared_he *new_entry;
2852 HE **const head = &HvARRAY(PL_strtab)[hindex];
2853 HE *const next = *head;
2855 /* We don't actually store a HE from the arena and a regular HEK.
2856 Instead we allocate one chunk of memory big enough for both,
2857 and put the HEK straight after the HE. This way we can find the
2858 HE directly from the HEK.
2861 Newx(k, STRUCT_OFFSET(struct shared_he,
2862 shared_he_hek.hek_key[0]) + len + 2, char);
2863 new_entry = (struct shared_he *)k;
2864 entry = &(new_entry->shared_he_he);
2865 hek = &(new_entry->shared_he_hek);
2867 Copy(str, HEK_KEY(hek), len, char);
2868 HEK_KEY(hek)[len] = 0;
2870 HEK_HASH(hek) = hash;
2871 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2873 /* Still "point" to the HEK, so that other code need not know what
2875 HeKEY_hek(entry) = hek;
2876 entry->he_valu.hent_refcount = 0;
2877 HeNEXT(entry) = next;
2880 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2881 if (!next) { /* initial entry? */
2882 } else if ( DO_HSPLIT(xhv) ) {
2883 const STRLEN oldsize = xhv->xhv_max + 1;
2884 hsplit(PL_strtab, oldsize, oldsize * 2);
2888 ++entry->he_valu.hent_refcount;
2890 if (flags & HVhek_FREEKEY)
2893 return HeKEY_hek(entry);
2897 Perl_hv_placeholders_p(pTHX_ HV *hv)
2900 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2902 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2905 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2908 Perl_die(aTHX_ "panic: hv_placeholders_p");
2911 return &(mg->mg_len);
2916 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2919 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2921 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2923 return mg ? mg->mg_len : 0;
2927 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2930 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2932 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2937 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2938 Perl_die(aTHX_ "panic: hv_placeholders_set");
2940 /* else we don't need to add magic to record 0 placeholders. */
2944 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2949 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2951 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2956 value = &PL_sv_placeholder;
2959 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2962 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2965 case HVrhek_PV_UTF8:
2966 /* Create a string SV that directly points to the bytes in our
2968 value = newSV_type(SVt_PV);
2969 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2970 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2971 /* This stops anything trying to free it */
2972 SvLEN_set(value, 0);
2974 SvREADONLY_on(value);
2975 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2979 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2980 (UV)he->refcounted_he_data[0]);
2986 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2988 Generates and returns a C<HV *> representing the content of a
2989 C<refcounted_he> chain.
2990 I<flags> is currently unused and must be zero.
2995 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2999 U32 placeholders, max;
3002 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3005 /* We could chase the chain once to get an idea of the number of keys,
3006 and call ksplit. But for now we'll make a potentially inefficient
3007 hash with only 8 entries in its array. */
3012 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3013 HvARRAY(hv) = (HE**)array;
3019 U32 hash = chain->refcounted_he_hash;
3021 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3023 HE **oentry = &((HvARRAY(hv))[hash & max]);
3024 HE *entry = *oentry;
3027 for (; entry; entry = HeNEXT(entry)) {
3028 if (HeHASH(entry) == hash) {
3029 /* We might have a duplicate key here. If so, entry is older
3030 than the key we've already put in the hash, so if they are
3031 the same, skip adding entry. */
3033 const STRLEN klen = HeKLEN(entry);
3034 const char *const key = HeKEY(entry);
3035 if (klen == chain->refcounted_he_keylen
3036 && (!!HeKUTF8(entry)
3037 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3038 && memEQ(key, REF_HE_KEY(chain), klen))
3041 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3043 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3044 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3045 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3056 = share_hek_flags(REF_HE_KEY(chain),
3057 chain->refcounted_he_keylen,
3058 chain->refcounted_he_hash,
3059 (chain->refcounted_he_data[0]
3060 & (HVhek_UTF8|HVhek_WASUTF8)));
3062 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3064 value = refcounted_he_value(chain);
3065 if (value == &PL_sv_placeholder)
3067 HeVAL(entry) = value;
3069 /* Link it into the chain. */
3070 HeNEXT(entry) = *oentry;
3076 chain = chain->refcounted_he_next;
3080 clear_placeholders(hv, placeholders);
3081 HvTOTALKEYS(hv) -= placeholders;
3084 /* We could check in the loop to see if we encounter any keys with key
3085 flags, but it's probably not worth it, as this per-hash flag is only
3086 really meant as an optimisation for things like Storable. */
3088 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3094 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3096 Search along a C<refcounted_he> chain for an entry with the key specified
3097 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3098 bit set, the key octets are interpreted as UTF-8, otherwise they
3099 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3100 string, or zero if it has not been precomputed. Returns a mortal scalar
3101 representing the value associated with the key, or C<&PL_sv_placeholder>
3102 if there is no value associated with the key.
3108 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3109 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3113 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3115 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3116 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3119 return &PL_sv_placeholder;
3120 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3121 /* For searching purposes, canonicalise to Latin-1 where possible. */
3122 const char *keyend = keypv + keylen, *p;
3123 STRLEN nonascii_count = 0;
3124 for (p = keypv; p != keyend; p++) {
3125 if (! UTF8_IS_INVARIANT(*p)) {
3126 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3127 goto canonicalised_key;
3133 if (nonascii_count) {
3135 const char *p = keypv, *keyend = keypv + keylen;
3136 keylen -= nonascii_count;
3137 Newx(q, keylen, char);
3140 for (; p != keyend; p++, q++) {
3142 if (UTF8_IS_INVARIANT(c)) {
3147 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3151 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3152 canonicalised_key: ;
3154 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3156 PERL_HASH(hash, keypv, keylen);
3158 for (; chain; chain = chain->refcounted_he_next) {
3161 hash == chain->refcounted_he_hash &&
3162 keylen == chain->refcounted_he_keylen &&
3163 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3164 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3166 hash == HEK_HASH(chain->refcounted_he_hek) &&
3167 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3168 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3169 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3172 if (flags & REFCOUNTED_HE_EXISTS)
3173 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3175 ? NULL : &PL_sv_yes;
3176 return sv_2mortal(refcounted_he_value(chain));
3179 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3183 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3185 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3186 instead of a string/length pair.
3192 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3193 const char *key, U32 hash, U32 flags)
3195 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3196 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3200 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3202 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3209 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3210 SV *key, U32 hash, U32 flags)
3214 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3215 if (flags & REFCOUNTED_HE_KEY_UTF8)
3216 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3218 keypv = SvPV_const(key, keylen);
3220 flags |= REFCOUNTED_HE_KEY_UTF8;
3221 if (!hash && SvIsCOW_shared_hash(key))
3222 hash = SvSHARED_HASH(key);
3223 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3227 =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
3229 Creates a new C<refcounted_he>. This consists of a single key/value
3230 pair and a reference to an existing C<refcounted_he> chain (which may
3231 be empty), and thus forms a longer chain. When using the longer chain,
3232 the new key/value pair takes precedence over any entry for the same key
3233 further along the chain.
3235 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3236 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3237 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3238 a precomputed hash of the key string, or zero if it has not been
3241 I<value> is the scalar value to store for this key. I<value> is copied
3242 by this function, which thus does not take ownership of any reference
3243 to it, and later changes to the scalar will not be reflected in the
3244 value visible in the C<refcounted_he>. Complex types of scalar will not
3245 be stored with referential integrity, but will be coerced to strings.
3246 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3247 value is to be associated with the key; this, as with any non-null value,
3248 takes precedence over the existence of a value for the key further along
3251 I<parent> points to the rest of the C<refcounted_he> chain to be
3252 attached to the new C<refcounted_he>. This function takes ownership
3253 of one reference to I<parent>, and returns one reference to the new
3259 struct refcounted_he *
3260 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3261 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3264 STRLEN value_len = 0;
3265 const char *value_p = NULL;
3269 STRLEN key_offset = 1;
3270 struct refcounted_he *he;
3271 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3273 if (!value || value == &PL_sv_placeholder) {
3274 value_type = HVrhek_delete;
3275 } else if (SvPOK(value)) {
3276 value_type = HVrhek_PV;
3277 } else if (SvIOK(value)) {
3278 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3279 } else if (!SvOK(value)) {
3280 value_type = HVrhek_undef;
3282 value_type = HVrhek_PV;
3284 is_pv = value_type == HVrhek_PV;
3286 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3287 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3288 value_p = SvPV_const(value, value_len);
3290 value_type = HVrhek_PV_UTF8;
3291 key_offset = value_len + 2;
3293 hekflags = value_type;
3295 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3296 /* Canonicalise to Latin-1 where possible. */
3297 const char *keyend = keypv + keylen, *p;
3298 STRLEN nonascii_count = 0;
3299 for (p = keypv; p != keyend; p++) {
3300 if (! UTF8_IS_INVARIANT(*p)) {
3301 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3302 goto canonicalised_key;
3308 if (nonascii_count) {
3310 const char *p = keypv, *keyend = keypv + keylen;
3311 keylen -= nonascii_count;
3312 Newx(q, keylen, char);
3315 for (; p != keyend; p++, q++) {
3317 if (UTF8_IS_INVARIANT(c)) {
3322 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3326 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3327 canonicalised_key: ;
3329 if (flags & REFCOUNTED_HE_KEY_UTF8)
3330 hekflags |= HVhek_UTF8;
3332 PERL_HASH(hash, keypv, keylen);
3335 he = (struct refcounted_he*)
3336 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3340 he = (struct refcounted_he*)
3341 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3345 he->refcounted_he_next = parent;
3348 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3349 he->refcounted_he_val.refcounted_he_u_len = value_len;
3350 } else if (value_type == HVrhek_IV) {
3351 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3352 } else if (value_type == HVrhek_UV) {
3353 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3357 he->refcounted_he_hash = hash;
3358 he->refcounted_he_keylen = keylen;
3359 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3361 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3364 he->refcounted_he_data[0] = hekflags;
3365 he->refcounted_he_refcnt = 1;
3371 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3373 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3374 of a string/length pair.
3379 struct refcounted_he *
3380 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3381 const char *key, U32 hash, SV *value, U32 flags)
3383 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3384 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3388 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3390 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3396 struct refcounted_he *
3397 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3398 SV *key, U32 hash, SV *value, U32 flags)
3402 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3403 if (flags & REFCOUNTED_HE_KEY_UTF8)
3404 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3406 keypv = SvPV_const(key, keylen);
3408 flags |= REFCOUNTED_HE_KEY_UTF8;
3409 if (!hash && SvIsCOW_shared_hash(key))
3410 hash = SvSHARED_HASH(key);
3411 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3415 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3417 Decrements the reference count of a C<refcounted_he> by one. If the
3418 reference count reaches zero the structure's memory is freed, which
3419 (recursively) causes a reduction of its parent C<refcounted_he>'s
3420 reference count. It is safe to pass a null pointer to this function:
3421 no action occurs in this case.
3427 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3429 PERL_UNUSED_CONTEXT;
3432 struct refcounted_he *copy;
3436 new_count = --he->refcounted_he_refcnt;
3437 HINTS_REFCNT_UNLOCK;
3443 #ifndef USE_ITHREADS
3444 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3447 he = he->refcounted_he_next;
3448 PerlMemShared_free(copy);
3453 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3455 Increment the reference count of a C<refcounted_he>. The pointer to the
3456 C<refcounted_he> is also returned. It is safe to pass a null pointer
3457 to this function: no action occurs and a null pointer is returned.
3462 struct refcounted_he *
3463 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3468 he->refcounted_he_refcnt++;
3469 HINTS_REFCNT_UNLOCK;
3475 =for apidoc cop_fetch_label
3477 Returns the label attached to a cop.
3478 The flags pointer may be set to C<SVf_UTF8> or 0.
3483 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3486 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3487 struct refcounted_he *const chain = cop->cop_hints_hash;
3489 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3494 if (chain->refcounted_he_keylen != 1)
3496 if (*REF_HE_KEY(chain) != ':')
3499 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3501 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3504 /* Stop anyone trying to really mess us up by adding their own value for
3506 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3507 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3511 *len = chain->refcounted_he_val.refcounted_he_u_len;
3513 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3514 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3516 return chain->refcounted_he_data + 1;
3520 =for apidoc cop_store_label
3522 Save a label into a C<cop_hints_hash>. You need to set flags to C<SVf_UTF8>
3529 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3533 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3535 if (flags & ~(SVf_UTF8))
3536 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3538 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3539 if (flags & SVf_UTF8)
3542 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3546 =for apidoc hv_assert
3548 Check that a hash is in an internally consistent state.
3556 Perl_hv_assert(pTHX_ HV *hv)
3561 int placeholders = 0;
3564 const I32 riter = HvRITER_get(hv);
3565 HE *eiter = HvEITER_get(hv);
3567 PERL_ARGS_ASSERT_HV_ASSERT;
3569 (void)hv_iterinit(hv);
3571 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3572 /* sanity check the values */
3573 if (HeVAL(entry) == &PL_sv_placeholder)
3577 /* sanity check the keys */
3578 if (HeSVKEY(entry)) {
3579 NOOP; /* Don't know what to check on SV keys. */
3580 } else if (HeKUTF8(entry)) {
3582 if (HeKWASUTF8(entry)) {
3583 PerlIO_printf(Perl_debug_log,
3584 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3585 (int) HeKLEN(entry), HeKEY(entry));
3588 } else if (HeKWASUTF8(entry))
3591 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3592 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3593 const int nhashkeys = HvUSEDKEYS(hv);
3594 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3596 if (nhashkeys != real) {
3597 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3600 if (nhashplaceholders != placeholders) {
3601 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3605 if (withflags && ! HvHASKFLAGS(hv)) {
3606 PerlIO_printf(Perl_debug_log,
3607 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3612 sv_dump(MUTABLE_SV(hv));
3614 HvRITER_set(hv, riter); /* Restore hash iterator state */
3615 HvEITER_set(hv, eiter);
3622 * c-indentation-style: bsd
3624 * indent-tabs-mode: nil
3627 * ex: set ts=8 sts=4 sw=4 et: