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
904 when the hash is tied.
910 Perl_hv_scalar(pTHX_ HV *hv)
914 PERL_ARGS_ASSERT_HV_SCALAR;
916 if (SvRMAGICAL(hv)) {
917 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
919 return magic_scalarpack(hv, mg);
923 if (HvTOTALKEYS((const HV *)hv))
924 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
925 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
933 =for apidoc hv_delete
935 Deletes a key/value pair in the hash. The value's SV is removed from
936 the hash, made mortal, and returned to the caller. The absolute
937 value of C<klen> is the length of the key. If C<klen> is negative the
938 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
939 will normally be zero; if set to G_DISCARD then NULL will be returned.
940 NULL will also be returned if the key is not found.
942 =for apidoc hv_delete_ent
944 Deletes a key/value pair in the hash. The value SV is removed from the hash,
945 made mortal, and returned to the caller. The C<flags> value will normally be
946 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
947 returned if the key is not found. C<hash> can be a valid precomputed hash
948 value, or 0 to ask for it to be computed.
954 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
955 int k_flags, I32 d_flags, U32 hash)
961 HE *const *first_entry;
962 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
965 if (SvRMAGICAL(hv)) {
968 hv_magic_check (hv, &needs_copy, &needs_store);
972 entry = (HE *) hv_common(hv, keysv, key, klen,
973 k_flags & ~HVhek_FREEKEY,
974 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
976 sv = entry ? HeVAL(entry) : NULL;
982 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
983 /* No longer an element */
984 sv_unmagic(sv, PERL_MAGIC_tiedelem);
987 return NULL; /* element cannot be deleted */
989 #ifdef ENV_IS_CASELESS
990 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
991 /* XXX This code isn't UTF8 clean. */
992 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
993 if (k_flags & HVhek_FREEKEY) {
996 key = strupr(SvPVX(keysv));
1005 xhv = (XPVHV*)SvANY(hv);
1009 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1010 const char * const keysave = key;
1011 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1014 k_flags |= HVhek_UTF8;
1016 k_flags &= ~HVhek_UTF8;
1017 if (key != keysave) {
1018 if (k_flags & HVhek_FREEKEY) {
1019 /* This shouldn't happen if our caller does what we expect,
1020 but strictly the API allows it. */
1023 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1025 HvHASKFLAGS_on(MUTABLE_SV(hv));
1029 if (keysv && (SvIsCOW_shared_hash(keysv)))
1030 hash = SvSHARED_HASH(keysv);
1032 PERL_HASH(hash, key, klen);
1035 masked_flags = (k_flags & HVhek_MASK);
1037 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1039 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1041 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1045 if (HeHASH(entry) != hash) /* strings can't be equal */
1047 if (HeKLEN(entry) != (I32)klen)
1049 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1051 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1054 if (hv == PL_strtab) {
1055 if (k_flags & HVhek_FREEKEY)
1057 Perl_croak(aTHX_ S_strtab_error, "delete");
1060 /* if placeholder is here, it's already been deleted.... */
1061 if (HeVAL(entry) == &PL_sv_placeholder) {
1062 if (k_flags & HVhek_FREEKEY)
1066 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1067 hv_notallowed(k_flags, key, klen,
1068 "Attempt to delete readonly key '%"SVf"' from"
1069 " a restricted hash");
1071 if (k_flags & HVhek_FREEKEY)
1074 /* If this is a stash and the key ends with ::, then someone is
1075 * deleting a package.
1077 if (HeVAL(entry) && HvENAME_get(hv)) {
1078 gv = (GV *)HeVAL(entry);
1079 if (keysv) key = SvPV(keysv, klen);
1081 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1083 (klen == 1 && key[0] == ':')
1085 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1086 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1087 && HvENAME_get(stash)) {
1088 /* A previous version of this code checked that the
1089 * GV was still in the symbol table by fetching the
1090 * GV with its name. That is not necessary (and
1091 * sometimes incorrect), as HvENAME cannot be set
1092 * on hv if it is not in the symtab. */
1094 /* Hang on to it for a bit. */
1095 SvREFCNT_inc_simple_void_NN(
1096 sv_2mortal((SV *)gv)
1099 else if (klen == 3 && strnEQ(key, "ISA", 3))
1103 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1104 HeVAL(entry) = &PL_sv_placeholder;
1106 /* deletion of method from stash */
1107 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1109 mro_method_changed_in(hv);
1113 * If a restricted hash, rather than really deleting the entry, put
1114 * a placeholder there. This marks the key as being "approved", so
1115 * we can still access via not-really-existing key without raising
1119 /* We'll be saving this slot, so the number of allocated keys
1120 * doesn't go down, but the number placeholders goes up */
1121 HvPLACEHOLDERS(hv)++;
1123 *oentry = HeNEXT(entry);
1124 if(!*first_entry && SvOOK(hv)) {
1125 /* removed last entry, and aux struct present. */
1126 struct xpvhv_aux *const aux = HvAUX(hv);
1127 if (aux->xhv_fill_lazy)
1128 --aux->xhv_fill_lazy;
1130 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1133 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1134 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1135 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1136 hv_free_ent(hv, entry);
1138 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1139 if (xhv->xhv_keys == 0)
1140 HvHASKFLAGS_off(hv);
1143 if (d_flags & G_DISCARD) {
1148 if (mro_changes == 1) mro_isa_changed_in(hv);
1149 else if (mro_changes == 2)
1150 mro_package_moved(NULL, stash, gv, 1);
1154 if (SvREADONLY(hv)) {
1155 hv_notallowed(k_flags, key, klen,
1156 "Attempt to delete disallowed key '%"SVf"' from"
1157 " a restricted hash");
1160 if (k_flags & HVhek_FREEKEY)
1166 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1170 char *a = (char*) HvARRAY(hv);
1173 PERL_ARGS_ASSERT_HSPLIT;
1175 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1176 (void*)hv, (int) oldsize);*/
1179 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1180 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1185 #ifdef PERL_HASH_RANDOMIZE_KEYS
1186 /* the idea of this is that we create a "random" value by hashing the address of
1187 * the array, we then use the low bit to decide if we insert at the top, or insert
1188 * second from top. After each such insert we rotate the hashed value. So we can
1189 * use the same hashed value over and over, and in normal build environments use
1190 * very few ops to do so. ROTL32() should produce a single machine operation. */
1191 if (PL_HASH_RAND_BITS_ENABLED) {
1192 if (PL_HASH_RAND_BITS_ENABLED == 1)
1193 PL_hash_rand_bits += ptr_hash((PTRV)a);
1194 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1199 struct xpvhv_aux *const dest
1200 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1201 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1202 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1203 #ifdef PERL_HASH_RANDOMIZE_KEYS
1204 dest->xhv_rand = (U32)PL_hash_rand_bits;
1206 /* For now, just reset the lazy fill counter.
1207 It would be possible to update the counter in the code below
1209 dest->xhv_fill_lazy = 0;
1213 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1214 HvMAX(hv) = --newsize;
1215 HvARRAY(hv) = (HE**) a;
1217 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1222 HE **oentry = aep + i;
1225 if (!entry) /* non-existent */
1228 U32 j = (HeHASH(entry) & newsize);
1230 *oentry = HeNEXT(entry);
1231 #ifdef PERL_HASH_RANDOMIZE_KEYS
1232 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1233 * insert to top, otherwise rotate the bucket rand 1 bit,
1234 * and use the new low bit to decide if we insert at top,
1235 * or next from top. IOW, we only rotate on a collision.*/
1236 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1237 PL_hash_rand_bits+= ROTL_UV(HeHASH(entry), 17);
1238 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1239 if (PL_hash_rand_bits & 1) {
1240 HeNEXT(entry)= HeNEXT(aep[j]);
1241 HeNEXT(aep[j])= entry;
1243 /* Note, this is structured in such a way as the optimizer
1244 * should eliminate the duplicated code here and below without
1245 * us needing to explicitly use a goto. */
1246 HeNEXT(entry) = aep[j];
1252 /* see comment above about duplicated code */
1253 HeNEXT(entry) = aep[j];
1258 oentry = &HeNEXT(entry);
1262 } while (i++ < oldsize);
1266 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1269 XPVHV* xhv = (XPVHV*)SvANY(hv);
1270 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1274 PERL_ARGS_ASSERT_HV_KSPLIT;
1276 newsize = (I32) newmax; /* possible truncation here */
1277 if (newsize != newmax || newmax <= oldsize)
1279 while ((newsize & (1 + ~newsize)) != newsize) {
1280 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1282 if (newsize < newmax)
1284 if (newsize < newmax)
1285 return; /* overflow detection */
1287 a = (char *) HvARRAY(hv);
1289 hsplit(hv, oldsize, newsize);
1291 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1292 xhv->xhv_max = --newsize;
1293 HvARRAY(hv) = (HE **) a;
1297 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1298 * as tied hashes could play silly buggers and mess us around. We will
1299 * do the right thing during hv_store() afterwards, but still - Yves */
1300 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1301 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1302 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1303 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1305 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1306 hv_max = hv_max / 2; \
1308 HvMAX(hv) = hv_max; \
1313 Perl_newHVhv(pTHX_ HV *ohv)
1316 HV * const hv = newHV();
1319 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1321 hv_max = HvMAX(ohv);
1323 if (!SvMAGICAL((const SV *)ohv)) {
1324 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1326 const bool shared = !!HvSHAREKEYS(ohv);
1327 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1329 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1332 /* In each bucket... */
1333 for (i = 0; i <= hv_max; i++) {
1335 HE *oent = oents[i];
1342 /* Copy the linked list of entries. */
1343 for (; oent; oent = HeNEXT(oent)) {
1344 const U32 hash = HeHASH(oent);
1345 const char * const key = HeKEY(oent);
1346 const STRLEN len = HeKLEN(oent);
1347 const int flags = HeKFLAGS(oent);
1348 HE * const ent = new_HE();
1349 SV *const val = HeVAL(oent);
1351 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1353 = shared ? share_hek_flags(key, len, hash, flags)
1354 : save_hek_flags(key, len, hash, flags);
1365 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1369 /* Iterate over ohv, copying keys and values one at a time. */
1371 const I32 riter = HvRITER_get(ohv);
1372 HE * const eiter = HvEITER_get(ohv);
1373 STRLEN hv_keys = HvTOTALKEYS(ohv);
1375 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1378 while ((entry = hv_iternext_flags(ohv, 0))) {
1379 SV *val = hv_iterval(ohv,entry);
1380 SV * const keysv = HeSVKEY(entry);
1381 val = SvIMMORTAL(val) ? val : newSVsv(val);
1383 (void)hv_store_ent(hv, keysv, val, 0);
1385 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1386 HeHASH(entry), HeKFLAGS(entry));
1388 HvRITER_set(ohv, riter);
1389 HvEITER_set(ohv, eiter);
1396 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1398 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1399 a pointer to a hash (which may have C<%^H> magic, but should be generally
1400 non-magical), or C<NULL> (interpreted as an empty hash). The content
1401 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1402 added to it. A pointer to the new hash is returned.
1408 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1410 HV * const hv = newHV();
1413 STRLEN hv_max = HvMAX(ohv);
1414 STRLEN hv_keys = HvTOTALKEYS(ohv);
1416 const I32 riter = HvRITER_get(ohv);
1417 HE * const eiter = HvEITER_get(ohv);
1422 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1425 while ((entry = hv_iternext_flags(ohv, 0))) {
1426 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1427 SV *heksv = HeSVKEY(entry);
1428 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1429 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1430 (char *)heksv, HEf_SVKEY);
1431 if (heksv == HeSVKEY(entry))
1432 (void)hv_store_ent(hv, heksv, sv, 0);
1434 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1435 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1436 SvREFCNT_dec_NN(heksv);
1439 HvRITER_set(ohv, riter);
1440 HvEITER_set(ohv, eiter);
1442 SvREFCNT_inc_simple_void_NN(hv);
1445 hv_magic(hv, NULL, PERL_MAGIC_hints);
1448 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1450 /* like hv_free_ent, but returns the SV rather than freeing it */
1452 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1457 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1460 if (HeKLEN(entry) == HEf_SVKEY) {
1461 SvREFCNT_dec(HeKEY_sv(entry));
1462 Safefree(HeKEY_hek(entry));
1464 else if (HvSHAREKEYS(hv))
1465 unshare_hek(HeKEY_hek(entry));
1467 Safefree(HeKEY_hek(entry));
1474 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1479 PERL_ARGS_ASSERT_HV_FREE_ENT;
1483 val = hv_free_ent_ret(hv, entry);
1489 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1493 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1497 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1498 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1499 if (HeKLEN(entry) == HEf_SVKEY) {
1500 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1502 hv_free_ent(hv, entry);
1506 =for apidoc hv_clear
1508 Frees the all the elements of a hash, leaving it empty.
1509 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1511 If any destructors are triggered as a result, the hv itself may
1518 Perl_hv_clear(pTHX_ HV *hv)
1525 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1527 xhv = (XPVHV*)SvANY(hv);
1530 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1531 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1532 /* restricted hash: convert all keys to placeholders */
1534 for (i = 0; i <= xhv->xhv_max; i++) {
1535 HE *entry = (HvARRAY(hv))[i];
1536 for (; entry; entry = HeNEXT(entry)) {
1537 /* not already placeholder */
1538 if (HeVAL(entry) != &PL_sv_placeholder) {
1540 if (SvREADONLY(HeVAL(entry))) {
1541 SV* const keysv = hv_iterkeysv(entry);
1542 Perl_croak_nocontext(
1543 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1546 SvREFCNT_dec_NN(HeVAL(entry));
1548 HeVAL(entry) = &PL_sv_placeholder;
1549 HvPLACEHOLDERS(hv)++;
1556 HvPLACEHOLDERS_set(hv, 0);
1559 mg_clear(MUTABLE_SV(hv));
1561 HvHASKFLAGS_off(hv);
1565 mro_isa_changed_in(hv);
1566 HvEITER_set(hv, NULL);
1572 =for apidoc hv_clear_placeholders
1574 Clears any placeholders from a hash. If a restricted hash has any of its keys
1575 marked as readonly and the key is subsequently deleted, the key is not actually
1576 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1577 it so it will be ignored by future operations such as iterating over the hash,
1578 but will still allow the hash to have a value reassigned to the key at some
1579 future point. This function clears any such placeholder keys from the hash.
1580 See Hash::Util::lock_keys() for an example of its use.
1586 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1589 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1591 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1594 clear_placeholders(hv, items);
1598 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1603 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1610 /* Loop down the linked list heads */
1611 HE **oentry = &(HvARRAY(hv))[i];
1614 while ((entry = *oentry)) {
1615 if (HeVAL(entry) == &PL_sv_placeholder) {
1616 *oentry = HeNEXT(entry);
1617 if (entry == HvEITER_get(hv))
1620 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1621 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1622 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1623 hv_free_ent(hv, entry);
1628 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1629 if (HvUSEDKEYS(hv) == 0)
1630 HvHASKFLAGS_off(hv);
1631 HvPLACEHOLDERS_set(hv, 0);
1635 oentry = &HeNEXT(entry);
1639 /* You can't get here, hence assertion should always fail. */
1640 assert (items == 0);
1645 S_hfreeentries(pTHX_ HV *hv)
1648 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1651 PERL_ARGS_ASSERT_HFREEENTRIES;
1653 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1659 /* hfree_next_entry()
1660 * For use only by S_hfreeentries() and sv_clear().
1661 * Delete the next available HE from hv and return the associated SV.
1662 * Returns null on empty hash. Nevertheless null is not a reliable
1663 * indicator that the hash is empty, as the deleted entry may have a
1665 * indexp is a pointer to the current index into HvARRAY. The index should
1666 * initially be set to 0. hfree_next_entry() may update it. */
1669 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1671 struct xpvhv_aux *iter;
1675 STRLEN orig_index = *indexp;
1678 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1680 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1681 if ((entry = iter->xhv_eiter)) {
1682 /* the iterator may get resurrected after each
1683 * destructor call, so check each time */
1684 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1686 hv_free_ent(hv, entry);
1687 /* warning: at this point HvARRAY may have been
1688 * re-allocated, HvMAX changed etc */
1690 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1691 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1692 #ifdef PERL_HASH_RANDOMIZE_KEYS
1693 iter->xhv_last_rand = iter->xhv_rand;
1696 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1697 will actually call HvFILL() on a hash under destruction, so it
1698 seems pointless attempting to track the number of keys remaining.
1699 But if they do, we want to reset it again. */
1700 if (iter->xhv_fill_lazy)
1701 iter->xhv_fill_lazy = 0;
1704 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1707 array = HvARRAY(hv);
1709 while ( ! ((entry = array[*indexp])) ) {
1710 if ((*indexp)++ >= HvMAX(hv))
1712 assert(*indexp != orig_index);
1714 array[*indexp] = HeNEXT(entry);
1715 ((XPVHV*) SvANY(hv))->xhv_keys--;
1717 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1718 && HeVAL(entry) && isGV(HeVAL(entry))
1719 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1722 const char * const key = HePV(entry,klen);
1723 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1724 || (klen == 1 && key[0] == ':')) {
1726 NULL, GvHV(HeVAL(entry)),
1727 (GV *)HeVAL(entry), 0
1731 return hv_free_ent_ret(hv, entry);
1736 =for apidoc hv_undef
1738 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1740 As well as freeing all the elements of the hash (like hv_clear()), this
1741 also frees any auxiliary data and storage associated with the hash.
1743 If any destructors are triggered as a result, the hv itself may
1746 See also L</hv_clear>.
1752 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 && 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_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1779 hv_name_set(hv, NULL, 0, 0);
1783 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1787 struct xpvhv_aux * const aux = HvAUX(hv);
1788 struct mro_meta *meta;
1791 if (HvENAME_get(hv)) {
1792 if (PL_phase != PERL_PHASE_DESTRUCT)
1793 mro_isa_changed_in(hv);
1794 if (PL_stashcache) {
1795 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1796 HEKf"'\n", HvENAME_HEK(hv)));
1797 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1801 /* If this call originated from sv_clear, then we must check for
1802 * effective names that need freeing, as well as the usual name. */
1804 if (flags & HV_NAME_SETALL ? !!aux->xhv_name_u.xhvnameu_name : !!name) {
1805 if (name && PL_stashcache) {
1806 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1807 HEKf"'\n", HvNAME_HEK(hv)));
1808 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1810 hv_name_set(hv, NULL, 0, flags);
1812 if((meta = aux->xhv_mro_meta)) {
1813 if (meta->mro_linear_all) {
1814 SvREFCNT_dec_NN(meta->mro_linear_all);
1815 /* mro_linear_current is just acting as a shortcut pointer,
1819 /* Only the current MRO is stored, so this owns the data.
1821 SvREFCNT_dec(meta->mro_linear_current);
1822 SvREFCNT_dec(meta->mro_nextmethod);
1823 SvREFCNT_dec(meta->isa);
1824 SvREFCNT_dec(meta->super);
1826 aux->xhv_mro_meta = NULL;
1828 if (!aux->xhv_name_u.xhvnameu_name && ! aux->xhv_backreferences)
1829 SvFLAGS(hv) &= ~SVf_OOK;
1832 Safefree(HvARRAY(hv));
1833 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1836 /* if we're freeing the HV, the SvMAGIC field has been reused for
1837 * other purposes, and so there can't be any placeholder magic */
1839 HvPLACEHOLDERS_set(hv, 0);
1842 mg_clear(MUTABLE_SV(hv));
1849 Returns the number of hash buckets that
1850 happen to be in use. This function is
1851 wrapped by the macro C<HvFILL>.
1853 Previously this value was always stored in the HV structure, which created an
1854 overhead on every hash (and pretty much every object) for something that was
1855 rarely used. Now we calculate it on demand the first
1856 time that it is needed, and cache it if that calculation
1857 is going to be costly to repeat. The cached
1858 value is updated by insertions and deletions, but (currently) discarded if
1865 Perl_hv_fill(pTHX_ HV *const hv)
1868 HE **ents = HvARRAY(hv);
1869 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1871 PERL_ARGS_ASSERT_HV_FILL;
1873 /* No keys implies no buckets used.
1874 One key can only possibly mean one bucket used. */
1875 if (HvTOTALKEYS(hv) < 2)
1876 return HvTOTALKEYS(hv);
1879 if (aux && aux->xhv_fill_lazy)
1880 return aux->xhv_fill_lazy;
1884 HE *const *const last = ents + HvMAX(hv);
1885 count = last + 1 - ents;
1890 } while (++ents <= last);
1894 if (aux->xhv_fill_lazy)
1895 assert(aux->xhv_fill_lazy == count);
1897 aux->xhv_fill_lazy = count;
1898 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1899 aux = hv_auxinit(hv);
1900 aux->xhv_fill_lazy = count;
1905 /* hash a pointer to a U32 - Used in the hash traversal randomization
1906 * and bucket order randomization code
1908 * this code was derived from Sereal, which was derived from autobox.
1911 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1914 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1915 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1917 u = (~u) + (u << 18);
1925 * This is one of Bob Jenkins' hash functions for 32-bit integers
1926 * from: http://burtleburtle.net/bob/hash/integer.html
1928 u = (u + 0x7ed55d16) + (u << 12);
1929 u = (u ^ 0xc761c23c) ^ (u >> 19);
1930 u = (u + 0x165667b1) + (u << 5);
1931 u = (u + 0xd3a2646c) ^ (u << 9);
1932 u = (u + 0xfd7046c5) + (u << 3);
1933 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1939 static struct xpvhv_aux*
1940 S_hv_auxinit(pTHX_ HV *hv) {
1941 struct xpvhv_aux *iter;
1944 PERL_ARGS_ASSERT_HV_AUXINIT;
1948 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1949 + sizeof(struct xpvhv_aux), char);
1951 array = (char *) HvARRAY(hv);
1952 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1953 + sizeof(struct xpvhv_aux), char);
1955 HvARRAY(hv) = (HE**)array;
1958 #ifdef PERL_HASH_RANDOMIZE_KEYS
1959 if (PL_HASH_RAND_BITS_ENABLED) {
1960 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
1961 if (PL_HASH_RAND_BITS_ENABLED == 1)
1962 PL_hash_rand_bits += ptr_hash((PTRV)array);
1963 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1965 iter->xhv_rand = (U32)PL_hash_rand_bits;
1971 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1972 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1973 #ifdef PERL_HASH_RANDOMIZE_KEYS
1974 iter->xhv_last_rand = iter->xhv_rand;
1976 iter->xhv_fill_lazy = 0;
1977 iter->xhv_name_u.xhvnameu_name = 0;
1978 iter->xhv_name_count = 0;
1979 iter->xhv_backreferences = 0;
1980 iter->xhv_mro_meta = NULL;
1985 =for apidoc hv_iterinit
1987 Prepares a starting point to traverse a hash table. Returns the number of
1988 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
1989 currently only meaningful for hashes without tie magic.
1991 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1992 hash buckets that happen to be in use. If you still need that esoteric
1993 value, you can get it through the macro C<HvFILL(hv)>.
2000 Perl_hv_iterinit(pTHX_ HV *hv)
2002 PERL_ARGS_ASSERT_HV_ITERINIT;
2004 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
2007 Perl_croak(aTHX_ "Bad hash");
2010 struct xpvhv_aux * const iter = HvAUX(hv);
2011 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2012 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2014 hv_free_ent(hv, entry);
2016 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2017 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2018 #ifdef PERL_HASH_RANDOMIZE_KEYS
2019 iter->xhv_last_rand = iter->xhv_rand;
2025 /* used to be xhv->xhv_fill before 5.004_65 */
2026 return HvTOTALKEYS(hv);
2030 Perl_hv_riter_p(pTHX_ HV *hv) {
2031 struct xpvhv_aux *iter;
2033 PERL_ARGS_ASSERT_HV_RITER_P;
2036 Perl_croak(aTHX_ "Bad hash");
2038 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2039 return &(iter->xhv_riter);
2043 Perl_hv_eiter_p(pTHX_ HV *hv) {
2044 struct xpvhv_aux *iter;
2046 PERL_ARGS_ASSERT_HV_EITER_P;
2049 Perl_croak(aTHX_ "Bad hash");
2051 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2052 return &(iter->xhv_eiter);
2056 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2057 struct xpvhv_aux *iter;
2059 PERL_ARGS_ASSERT_HV_RITER_SET;
2062 Perl_croak(aTHX_ "Bad hash");
2070 iter = hv_auxinit(hv);
2072 iter->xhv_riter = riter;
2076 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2077 struct xpvhv_aux *iter;
2079 PERL_ARGS_ASSERT_HV_RAND_SET;
2081 #ifdef PERL_HASH_RANDOMIZE_KEYS
2083 Perl_croak(aTHX_ "Bad hash");
2088 iter = hv_auxinit(hv);
2090 iter->xhv_rand = new_xhv_rand;
2092 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2097 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2098 struct xpvhv_aux *iter;
2100 PERL_ARGS_ASSERT_HV_EITER_SET;
2103 Perl_croak(aTHX_ "Bad hash");
2108 /* 0 is the default so don't go malloc()ing a new structure just to
2113 iter = hv_auxinit(hv);
2115 iter->xhv_eiter = eiter;
2119 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2122 struct xpvhv_aux *iter;
2126 PERL_ARGS_ASSERT_HV_NAME_SET;
2129 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2133 if (iter->xhv_name_u.xhvnameu_name) {
2134 if(iter->xhv_name_count) {
2135 if(flags & HV_NAME_SETALL) {
2136 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2137 HEK **hekp = name + (
2138 iter->xhv_name_count < 0
2139 ? -iter->xhv_name_count
2140 : iter->xhv_name_count
2142 while(hekp-- > name+1)
2143 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2144 /* The first elem may be null. */
2145 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2147 spot = &iter->xhv_name_u.xhvnameu_name;
2148 iter->xhv_name_count = 0;
2151 if(iter->xhv_name_count > 0) {
2152 /* shift some things over */
2154 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2156 spot = iter->xhv_name_u.xhvnameu_names;
2157 spot[iter->xhv_name_count] = spot[1];
2159 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2161 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2162 unshare_hek_or_pvn(*spot, 0, 0, 0);
2166 else if (flags & HV_NAME_SETALL) {
2167 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2168 spot = &iter->xhv_name_u.xhvnameu_name;
2171 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2172 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2173 iter->xhv_name_count = -2;
2174 spot = iter->xhv_name_u.xhvnameu_names;
2175 spot[1] = existing_name;
2178 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2183 iter = hv_auxinit(hv);
2184 spot = &iter->xhv_name_u.xhvnameu_name;
2186 PERL_HASH(hash, name, len);
2187 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2191 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2196 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2197 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2198 if (flags & SVf_UTF8)
2199 return (bytes_cmp_utf8(
2200 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2201 (const U8*)pv, pvlen) == 0);
2203 return (bytes_cmp_utf8(
2204 (const U8*)pv, pvlen,
2205 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2208 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2209 || memEQ(HEK_KEY(hek), pv, pvlen));
2213 =for apidoc hv_ename_add
2215 Adds a name to a stash's internal list of effective names. See
2218 This is called when a stash is assigned to a new location in the symbol
2225 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2228 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2231 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2234 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2236 PERL_HASH(hash, name, len);
2238 if (aux->xhv_name_count) {
2239 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2240 I32 count = aux->xhv_name_count;
2241 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2242 while (hekp-- > xhv_name)
2244 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2245 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2246 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2248 if (hekp == xhv_name && count < 0)
2249 aux->xhv_name_count = -count;
2252 if (count < 0) aux->xhv_name_count--, count = -count;
2253 else aux->xhv_name_count++;
2254 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2255 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2258 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2261 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2262 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2263 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2266 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2267 aux->xhv_name_count = existing_name ? 2 : -2;
2268 *aux->xhv_name_u.xhvnameu_names = existing_name;
2269 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2274 =for apidoc hv_ename_delete
2276 Removes a name from a stash's internal list of effective names. If this is
2277 the name returned by C<HvENAME>, then another name in the list will take
2278 its place (C<HvENAME> will use it).
2280 This is called when a stash is deleted from the symbol table.
2286 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2289 struct xpvhv_aux *aux;
2291 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2294 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2296 if (!SvOOK(hv)) return;
2299 if (!aux->xhv_name_u.xhvnameu_name) return;
2301 if (aux->xhv_name_count) {
2302 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2303 I32 const count = aux->xhv_name_count;
2304 HEK **victim = namep + (count < 0 ? -count : count);
2305 while (victim-- > namep + 1)
2307 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2308 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2309 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2311 unshare_hek_or_pvn(*victim, 0, 0, 0);
2312 if (count < 0) ++aux->xhv_name_count;
2313 else --aux->xhv_name_count;
2315 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2317 ) { /* if there are none left */
2319 aux->xhv_name_u.xhvnameu_names = NULL;
2320 aux->xhv_name_count = 0;
2323 /* Move the last one back to fill the empty slot. It
2324 does not matter what order they are in. */
2325 *victim = *(namep + (count < 0 ? -count : count) - 1);
2330 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2331 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2332 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2334 aux->xhv_name_count = -count;
2338 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2339 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2340 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2341 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2343 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2344 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2345 *aux->xhv_name_u.xhvnameu_names = namehek;
2346 aux->xhv_name_count = -1;
2351 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2352 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2354 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2355 PERL_UNUSED_CONTEXT;
2357 return &(iter->xhv_backreferences);
2361 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2364 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2369 av = HvAUX(hv)->xhv_backreferences;
2372 HvAUX(hv)->xhv_backreferences = 0;
2373 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2374 if (SvTYPE(av) == SVt_PVAV)
2375 SvREFCNT_dec_NN(av);
2380 hv_iternext is implemented as a macro in hv.h
2382 =for apidoc hv_iternext
2384 Returns entries from a hash iterator. See C<hv_iterinit>.
2386 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2387 iterator currently points to, without losing your place or invalidating your
2388 iterator. Note that in this case the current entry is deleted from the hash
2389 with your iterator holding the last reference to it. Your iterator is flagged
2390 to free the entry on the next call to C<hv_iternext>, so you must not discard
2391 your iterator immediately else the entry will leak - call C<hv_iternext> to
2392 trigger the resource deallocation.
2394 =for apidoc hv_iternext_flags
2396 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2397 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2398 set the placeholders keys (for restricted hashes) will be returned in addition
2399 to normal keys. By default placeholders are automatically skipped over.
2400 Currently a placeholder is implemented with a value that is
2401 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2402 restricted hashes may change, and the implementation currently is
2403 insufficiently abstracted for any change to be tidy.
2409 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2416 struct xpvhv_aux *iter;
2418 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2421 Perl_croak(aTHX_ "Bad hash");
2423 xhv = (XPVHV*)SvANY(hv);
2426 /* Too many things (well, pp_each at least) merrily assume that you can
2427 call hv_iternext without calling hv_iterinit, so we'll have to deal
2433 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2434 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2435 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2436 SV * const key = sv_newmortal();
2438 sv_setsv(key, HeSVKEY_force(entry));
2439 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2440 HeSVKEY_set(entry, NULL);
2446 /* one HE per MAGICAL hash */
2447 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2448 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2450 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2452 HeKEY_hek(entry) = hek;
2453 HeKLEN(entry) = HEf_SVKEY;
2455 magic_nextpack(MUTABLE_SV(hv),mg,key);
2457 /* force key to stay around until next time */
2458 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2459 return entry; /* beware, hent_val is not set */
2461 SvREFCNT_dec(HeVAL(entry));
2462 Safefree(HeKEY_hek(entry));
2464 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2469 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2470 if (!entry && SvRMAGICAL((const SV *)hv)
2471 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2474 /* The prime_env_iter() on VMS just loaded up new hash values
2475 * so the iteration count needs to be reset back to the beginning
2479 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2484 /* hv_iterinit now ensures this. */
2485 assert (HvARRAY(hv));
2487 /* At start of hash, entry is NULL. */
2490 entry = HeNEXT(entry);
2491 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2493 * Skip past any placeholders -- don't want to include them in
2496 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2497 entry = HeNEXT(entry);
2502 #ifdef PERL_HASH_RANDOMIZE_KEYS
2503 if (iter->xhv_last_rand != iter->xhv_rand) {
2504 if (iter->xhv_riter != -1) {
2505 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2506 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2510 iter->xhv_last_rand = iter->xhv_rand;
2514 /* Skip the entire loop if the hash is empty. */
2515 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2516 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2518 /* OK. Come to the end of the current list. Grab the next one. */
2520 iter->xhv_riter++; /* HvRITER(hv)++ */
2521 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2522 /* There is no next one. End of the hash. */
2523 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2524 #ifdef PERL_HASH_RANDOMIZE_KEYS
2525 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2529 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2531 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2532 /* If we have an entry, but it's a placeholder, don't count it.
2534 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2535 entry = HeNEXT(entry);
2537 /* Will loop again if this linked list starts NULL
2538 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2539 or if we run through it and find only placeholders. */
2543 iter->xhv_riter = -1;
2544 #ifdef PERL_HASH_RANDOMIZE_KEYS
2545 iter->xhv_last_rand = iter->xhv_rand;
2549 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2551 hv_free_ent(hv, oldentry);
2554 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2559 =for apidoc hv_iterkey
2561 Returns the key from the current position of the hash iterator. See
2568 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2570 PERL_ARGS_ASSERT_HV_ITERKEY;
2572 if (HeKLEN(entry) == HEf_SVKEY) {
2574 char * const p = SvPV(HeKEY_sv(entry), len);
2579 *retlen = HeKLEN(entry);
2580 return HeKEY(entry);
2584 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2586 =for apidoc hv_iterkeysv
2588 Returns the key as an C<SV*> from the current position of the hash
2589 iterator. The return value will always be a mortal copy of the key. Also
2596 Perl_hv_iterkeysv(pTHX_ HE *entry)
2598 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2600 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2604 =for apidoc hv_iterval
2606 Returns the value from the current position of the hash iterator. See
2613 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2615 PERL_ARGS_ASSERT_HV_ITERVAL;
2617 if (SvRMAGICAL(hv)) {
2618 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2619 SV* const sv = sv_newmortal();
2620 if (HeKLEN(entry) == HEf_SVKEY)
2621 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2623 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2627 return HeVAL(entry);
2631 =for apidoc hv_iternextsv
2633 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2640 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2642 HE * const he = hv_iternext_flags(hv, 0);
2644 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2648 *key = hv_iterkey(he, retlen);
2649 return hv_iterval(hv, he);
2656 =for apidoc hv_magic
2658 Adds magic to a hash. See C<sv_magic>.
2663 /* possibly free a shared string if no one has access to it
2664 * len and hash must both be valid for str.
2667 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2669 unshare_hek_or_pvn (NULL, str, len, hash);
2674 Perl_unshare_hek(pTHX_ HEK *hek)
2677 unshare_hek_or_pvn(hek, NULL, 0, 0);
2680 /* possibly free a shared string if no one has access to it
2681 hek if non-NULL takes priority over the other 3, else str, len and hash
2682 are used. If so, len and hash must both be valid for str.
2685 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2691 bool is_utf8 = FALSE;
2693 const char * const save = str;
2694 struct shared_he *he = NULL;
2697 /* Find the shared he which is just before us in memory. */
2698 he = (struct shared_he *)(((char *)hek)
2699 - STRUCT_OFFSET(struct shared_he,
2702 /* Assert that the caller passed us a genuine (or at least consistent)
2704 assert (he->shared_he_he.hent_hek == hek);
2706 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2707 --he->shared_he_he.he_valu.hent_refcount;
2711 hash = HEK_HASH(hek);
2712 } else if (len < 0) {
2713 STRLEN tmplen = -len;
2715 /* See the note in hv_fetch(). --jhi */
2716 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2719 k_flags = HVhek_UTF8;
2721 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2724 /* what follows was the moral equivalent of:
2725 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2727 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2729 xhv = (XPVHV*)SvANY(PL_strtab);
2730 /* assert(xhv_array != 0) */
2731 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2733 const HE *const he_he = &(he->shared_he_he);
2734 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2739 const int flags_masked = k_flags & HVhek_MASK;
2740 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2741 if (HeHASH(entry) != hash) /* strings can't be equal */
2743 if (HeKLEN(entry) != len)
2745 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2747 if (HeKFLAGS(entry) != flags_masked)
2754 if (--entry->he_valu.hent_refcount == 0) {
2755 *oentry = HeNEXT(entry);
2757 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2762 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2763 "Attempt to free nonexistent shared string '%s'%s"
2765 hek ? HEK_KEY(hek) : str,
2766 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2767 if (k_flags & HVhek_FREEKEY)
2771 /* get a (constant) string ptr from the global string table
2772 * string will get added if it is not already there.
2773 * len and hash must both be valid for str.
2776 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2778 bool is_utf8 = FALSE;
2780 const char * const save = str;
2782 PERL_ARGS_ASSERT_SHARE_HEK;
2785 STRLEN tmplen = -len;
2787 /* See the note in hv_fetch(). --jhi */
2788 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2790 /* If we were able to downgrade here, then than means that we were passed
2791 in a key which only had chars 0-255, but was utf8 encoded. */
2794 /* If we found we were able to downgrade the string to bytes, then
2795 we should flag that it needs upgrading on keys or each. Also flag
2796 that we need share_hek_flags to free the string. */
2799 PERL_HASH(hash, str, len);
2800 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2804 return share_hek_flags (str, len, hash, flags);
2808 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2812 const int flags_masked = flags & HVhek_MASK;
2813 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2814 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2816 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2818 /* what follows is the moral equivalent of:
2820 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2821 hv_store(PL_strtab, str, len, NULL, hash);
2823 Can't rehash the shared string table, so not sure if it's worth
2824 counting the number of entries in the linked list
2827 /* assert(xhv_array != 0) */
2828 entry = (HvARRAY(PL_strtab))[hindex];
2829 for (;entry; entry = HeNEXT(entry)) {
2830 if (HeHASH(entry) != hash) /* strings can't be equal */
2832 if (HeKLEN(entry) != len)
2834 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2836 if (HeKFLAGS(entry) != flags_masked)
2842 /* What used to be head of the list.
2843 If this is NULL, then we're the first entry for this slot, which
2844 means we need to increate fill. */
2845 struct shared_he *new_entry;
2848 HE **const head = &HvARRAY(PL_strtab)[hindex];
2849 HE *const next = *head;
2851 /* We don't actually store a HE from the arena and a regular HEK.
2852 Instead we allocate one chunk of memory big enough for both,
2853 and put the HEK straight after the HE. This way we can find the
2854 HE directly from the HEK.
2857 Newx(k, STRUCT_OFFSET(struct shared_he,
2858 shared_he_hek.hek_key[0]) + len + 2, char);
2859 new_entry = (struct shared_he *)k;
2860 entry = &(new_entry->shared_he_he);
2861 hek = &(new_entry->shared_he_hek);
2863 Copy(str, HEK_KEY(hek), len, char);
2864 HEK_KEY(hek)[len] = 0;
2866 HEK_HASH(hek) = hash;
2867 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2869 /* Still "point" to the HEK, so that other code need not know what
2871 HeKEY_hek(entry) = hek;
2872 entry->he_valu.hent_refcount = 0;
2873 HeNEXT(entry) = next;
2876 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2877 if (!next) { /* initial entry? */
2878 } else if ( DO_HSPLIT(xhv) ) {
2879 const STRLEN oldsize = xhv->xhv_max + 1;
2880 hsplit(PL_strtab, oldsize, oldsize * 2);
2884 ++entry->he_valu.hent_refcount;
2886 if (flags & HVhek_FREEKEY)
2889 return HeKEY_hek(entry);
2893 Perl_hv_placeholders_p(pTHX_ HV *hv)
2896 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2898 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2901 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2904 Perl_die(aTHX_ "panic: hv_placeholders_p");
2907 return &(mg->mg_len);
2912 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2915 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2917 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2919 return mg ? mg->mg_len : 0;
2923 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2926 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2928 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2933 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2934 Perl_die(aTHX_ "panic: hv_placeholders_set");
2936 /* else we don't need to add magic to record 0 placeholders. */
2940 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2945 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2947 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2952 value = &PL_sv_placeholder;
2955 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2958 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2961 case HVrhek_PV_UTF8:
2962 /* Create a string SV that directly points to the bytes in our
2964 value = newSV_type(SVt_PV);
2965 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2966 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2967 /* This stops anything trying to free it */
2968 SvLEN_set(value, 0);
2970 SvREADONLY_on(value);
2971 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2975 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
2976 (UV)he->refcounted_he_data[0]);
2982 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
2984 Generates and returns a C<HV *> representing the content of a
2985 C<refcounted_he> chain.
2986 I<flags> is currently unused and must be zero.
2991 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
2995 U32 placeholders, max;
2998 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3001 /* We could chase the chain once to get an idea of the number of keys,
3002 and call ksplit. But for now we'll make a potentially inefficient
3003 hash with only 8 entries in its array. */
3008 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3009 HvARRAY(hv) = (HE**)array;
3015 U32 hash = chain->refcounted_he_hash;
3017 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3019 HE **oentry = &((HvARRAY(hv))[hash & max]);
3020 HE *entry = *oentry;
3023 for (; entry; entry = HeNEXT(entry)) {
3024 if (HeHASH(entry) == hash) {
3025 /* We might have a duplicate key here. If so, entry is older
3026 than the key we've already put in the hash, so if they are
3027 the same, skip adding entry. */
3029 const STRLEN klen = HeKLEN(entry);
3030 const char *const key = HeKEY(entry);
3031 if (klen == chain->refcounted_he_keylen
3032 && (!!HeKUTF8(entry)
3033 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3034 && memEQ(key, REF_HE_KEY(chain), klen))
3037 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3039 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3040 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3041 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3052 = share_hek_flags(REF_HE_KEY(chain),
3053 chain->refcounted_he_keylen,
3054 chain->refcounted_he_hash,
3055 (chain->refcounted_he_data[0]
3056 & (HVhek_UTF8|HVhek_WASUTF8)));
3058 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3060 value = refcounted_he_value(chain);
3061 if (value == &PL_sv_placeholder)
3063 HeVAL(entry) = value;
3065 /* Link it into the chain. */
3066 HeNEXT(entry) = *oentry;
3072 chain = chain->refcounted_he_next;
3076 clear_placeholders(hv, placeholders);
3077 HvTOTALKEYS(hv) -= placeholders;
3080 /* We could check in the loop to see if we encounter any keys with key
3081 flags, but it's probably not worth it, as this per-hash flag is only
3082 really meant as an optimisation for things like Storable. */
3084 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3090 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3092 Search along a C<refcounted_he> chain for an entry with the key specified
3093 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3094 bit set, the key octets are interpreted as UTF-8, otherwise they
3095 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3096 string, or zero if it has not been precomputed. Returns a mortal scalar
3097 representing the value associated with the key, or C<&PL_sv_placeholder>
3098 if there is no value associated with the key.
3104 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3105 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3109 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3111 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3112 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3115 return &PL_sv_placeholder;
3116 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3117 /* For searching purposes, canonicalise to Latin-1 where possible. */
3118 const char *keyend = keypv + keylen, *p;
3119 STRLEN nonascii_count = 0;
3120 for (p = keypv; p != keyend; p++) {
3121 if (! UTF8_IS_INVARIANT(*p)) {
3122 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3123 goto canonicalised_key;
3129 if (nonascii_count) {
3131 const char *p = keypv, *keyend = keypv + keylen;
3132 keylen -= nonascii_count;
3133 Newx(q, keylen, char);
3136 for (; p != keyend; p++, q++) {
3138 if (UTF8_IS_INVARIANT(c)) {
3143 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3147 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3148 canonicalised_key: ;
3150 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3152 PERL_HASH(hash, keypv, keylen);
3154 for (; chain; chain = chain->refcounted_he_next) {
3157 hash == chain->refcounted_he_hash &&
3158 keylen == chain->refcounted_he_keylen &&
3159 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3160 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3162 hash == HEK_HASH(chain->refcounted_he_hek) &&
3163 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3164 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3165 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3168 if (flags & REFCOUNTED_HE_EXISTS)
3169 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3171 ? NULL : &PL_sv_yes;
3172 return sv_2mortal(refcounted_he_value(chain));
3175 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3179 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3181 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3182 instead of a string/length pair.
3188 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3189 const char *key, U32 hash, U32 flags)
3191 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3192 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3196 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3198 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3205 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3206 SV *key, U32 hash, U32 flags)
3210 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3211 if (flags & REFCOUNTED_HE_KEY_UTF8)
3212 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3214 keypv = SvPV_const(key, keylen);
3216 flags |= REFCOUNTED_HE_KEY_UTF8;
3217 if (!hash && SvIsCOW_shared_hash(key))
3218 hash = SvSHARED_HASH(key);
3219 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3223 =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
3225 Creates a new C<refcounted_he>. This consists of a single key/value
3226 pair and a reference to an existing C<refcounted_he> chain (which may
3227 be empty), and thus forms a longer chain. When using the longer chain,
3228 the new key/value pair takes precedence over any entry for the same key
3229 further along the chain.
3231 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3232 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3233 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3234 a precomputed hash of the key string, or zero if it has not been
3237 I<value> is the scalar value to store for this key. I<value> is copied
3238 by this function, which thus does not take ownership of any reference
3239 to it, and later changes to the scalar will not be reflected in the
3240 value visible in the C<refcounted_he>. Complex types of scalar will not
3241 be stored with referential integrity, but will be coerced to strings.
3242 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3243 value is to be associated with the key; this, as with any non-null value,
3244 takes precedence over the existence of a value for the key further along
3247 I<parent> points to the rest of the C<refcounted_he> chain to be
3248 attached to the new C<refcounted_he>. This function takes ownership
3249 of one reference to I<parent>, and returns one reference to the new
3255 struct refcounted_he *
3256 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3257 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3260 STRLEN value_len = 0;
3261 const char *value_p = NULL;
3265 STRLEN key_offset = 1;
3266 struct refcounted_he *he;
3267 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3269 if (!value || value == &PL_sv_placeholder) {
3270 value_type = HVrhek_delete;
3271 } else if (SvPOK(value)) {
3272 value_type = HVrhek_PV;
3273 } else if (SvIOK(value)) {
3274 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3275 } else if (!SvOK(value)) {
3276 value_type = HVrhek_undef;
3278 value_type = HVrhek_PV;
3280 is_pv = value_type == HVrhek_PV;
3282 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3283 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3284 value_p = SvPV_const(value, value_len);
3286 value_type = HVrhek_PV_UTF8;
3287 key_offset = value_len + 2;
3289 hekflags = value_type;
3291 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3292 /* Canonicalise to Latin-1 where possible. */
3293 const char *keyend = keypv + keylen, *p;
3294 STRLEN nonascii_count = 0;
3295 for (p = keypv; p != keyend; p++) {
3296 if (! UTF8_IS_INVARIANT(*p)) {
3297 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3298 goto canonicalised_key;
3304 if (nonascii_count) {
3306 const char *p = keypv, *keyend = keypv + keylen;
3307 keylen -= nonascii_count;
3308 Newx(q, keylen, char);
3311 for (; p != keyend; p++, q++) {
3313 if (UTF8_IS_INVARIANT(c)) {
3318 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3322 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3323 canonicalised_key: ;
3325 if (flags & REFCOUNTED_HE_KEY_UTF8)
3326 hekflags |= HVhek_UTF8;
3328 PERL_HASH(hash, keypv, keylen);
3331 he = (struct refcounted_he*)
3332 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3336 he = (struct refcounted_he*)
3337 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3341 he->refcounted_he_next = parent;
3344 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3345 he->refcounted_he_val.refcounted_he_u_len = value_len;
3346 } else if (value_type == HVrhek_IV) {
3347 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3348 } else if (value_type == HVrhek_UV) {
3349 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3353 he->refcounted_he_hash = hash;
3354 he->refcounted_he_keylen = keylen;
3355 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3357 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3360 he->refcounted_he_data[0] = hekflags;
3361 he->refcounted_he_refcnt = 1;
3367 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3369 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3370 of a string/length pair.
3375 struct refcounted_he *
3376 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3377 const char *key, U32 hash, SV *value, U32 flags)
3379 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3380 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3384 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3386 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3392 struct refcounted_he *
3393 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3394 SV *key, U32 hash, SV *value, U32 flags)
3398 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3399 if (flags & REFCOUNTED_HE_KEY_UTF8)
3400 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3402 keypv = SvPV_const(key, keylen);
3404 flags |= REFCOUNTED_HE_KEY_UTF8;
3405 if (!hash && SvIsCOW_shared_hash(key))
3406 hash = SvSHARED_HASH(key);
3407 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3411 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3413 Decrements the reference count of a C<refcounted_he> by one. If the
3414 reference count reaches zero the structure's memory is freed, which
3415 (recursively) causes a reduction of its parent C<refcounted_he>'s
3416 reference count. It is safe to pass a null pointer to this function:
3417 no action occurs in this case.
3423 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3425 PERL_UNUSED_CONTEXT;
3428 struct refcounted_he *copy;
3432 new_count = --he->refcounted_he_refcnt;
3433 HINTS_REFCNT_UNLOCK;
3439 #ifndef USE_ITHREADS
3440 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3443 he = he->refcounted_he_next;
3444 PerlMemShared_free(copy);
3449 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3451 Increment the reference count of a C<refcounted_he>. The pointer to the
3452 C<refcounted_he> is also returned. It is safe to pass a null pointer
3453 to this function: no action occurs and a null pointer is returned.
3458 struct refcounted_he *
3459 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3464 he->refcounted_he_refcnt++;
3465 HINTS_REFCNT_UNLOCK;
3471 =for apidoc cop_fetch_label
3473 Returns the label attached to a cop.
3474 The flags pointer may be set to C<SVf_UTF8> or 0.
3479 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3482 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3483 struct refcounted_he *const chain = cop->cop_hints_hash;
3485 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3490 if (chain->refcounted_he_keylen != 1)
3492 if (*REF_HE_KEY(chain) != ':')
3495 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3497 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3500 /* Stop anyone trying to really mess us up by adding their own value for
3502 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3503 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3507 *len = chain->refcounted_he_val.refcounted_he_u_len;
3509 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3510 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3512 return chain->refcounted_he_data + 1;
3516 =for apidoc cop_store_label
3518 Save a label into a C<cop_hints_hash>.
3519 You need to set flags to C<SVf_UTF8>
3526 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3530 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3532 if (flags & ~(SVf_UTF8))
3533 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3535 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3536 if (flags & SVf_UTF8)
3539 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3543 =for apidoc hv_assert
3545 Check that a hash is in an internally consistent state.
3553 Perl_hv_assert(pTHX_ HV *hv)
3558 int placeholders = 0;
3561 const I32 riter = HvRITER_get(hv);
3562 HE *eiter = HvEITER_get(hv);
3564 PERL_ARGS_ASSERT_HV_ASSERT;
3566 (void)hv_iterinit(hv);
3568 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3569 /* sanity check the values */
3570 if (HeVAL(entry) == &PL_sv_placeholder)
3574 /* sanity check the keys */
3575 if (HeSVKEY(entry)) {
3576 NOOP; /* Don't know what to check on SV keys. */
3577 } else if (HeKUTF8(entry)) {
3579 if (HeKWASUTF8(entry)) {
3580 PerlIO_printf(Perl_debug_log,
3581 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3582 (int) HeKLEN(entry), HeKEY(entry));
3585 } else if (HeKWASUTF8(entry))
3588 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3589 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3590 const int nhashkeys = HvUSEDKEYS(hv);
3591 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3593 if (nhashkeys != real) {
3594 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3597 if (nhashplaceholders != placeholders) {
3598 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3602 if (withflags && ! HvHASKFLAGS(hv)) {
3603 PerlIO_printf(Perl_debug_log,
3604 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3609 sv_dump(MUTABLE_SV(hv));
3611 HvRITER_set(hv, riter); /* Restore hash iterator state */
3612 HvEITER_set(hv, eiter);
3619 * c-indentation-style: bsd
3621 * indent-tabs-mode: nil
3624 * ex: set ts=8 sts=4 sw=4 et: