3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
21 A HV structure represents a Perl hash. It consists mainly of an array
22 of pointers, each of which points to a linked list of HE structures. The
23 array is indexed by the hash function of the key, so each linked list
24 represents all the hash entries with the same hash value. Each HE contains
25 a pointer to the actual value, plus a pointer to a HEK structure which
26 holds the key and hash value.
34 #define PERL_HASH_INTERNAL_ACCESS
37 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
38 #define HV_FILL_THRESHOLD 31
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
45 #define new_HE() (HE*)safemalloc(sizeof(HE))
46 #define del_HE(p) safefree((char*)p)
55 void ** const root = &PL_body_roots[HE_SVSLOT];
58 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
65 #define new_HE() new_he()
68 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
69 PL_body_roots[HE_SVSLOT] = p; \
77 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
79 const int flags_masked = flags & HVhek_MASK;
83 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
85 Newx(k, HEK_BASESIZE + len + 2, char);
87 Copy(str, HEK_KEY(hek), len, char);
88 HEK_KEY(hek)[len] = 0;
91 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
93 if (flags & HVhek_FREEKEY)
98 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
102 Perl_free_tied_hv_pool(pTHX)
105 HE *he = PL_hv_fetch_ent_mh;
108 Safefree(HeKEY_hek(he));
112 PL_hv_fetch_ent_mh = NULL;
115 #if defined(USE_ITHREADS)
117 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
121 PERL_ARGS_ASSERT_HEK_DUP;
122 PERL_UNUSED_ARG(param);
127 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
129 /* We already shared this hash key. */
130 (void)share_hek_hek(shared);
134 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
135 HEK_HASH(source), HEK_FLAGS(source));
136 ptr_table_store(PL_ptr_table, source, shared);
142 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
146 PERL_ARGS_ASSERT_HE_DUP;
150 /* look for it in the table first */
151 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
155 /* create anew and remember what it is */
157 ptr_table_store(PL_ptr_table, e, ret);
159 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
160 if (HeKLEN(e) == HEf_SVKEY) {
162 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
163 HeKEY_hek(ret) = (HEK*)k;
164 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
167 /* This is hek_dup inlined, which seems to be important for speed
169 HEK * const source = HeKEY_hek(e);
170 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
173 /* We already shared this hash key. */
174 (void)share_hek_hek(shared);
178 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
179 HEK_HASH(source), HEK_FLAGS(source));
180 ptr_table_store(PL_ptr_table, source, shared);
182 HeKEY_hek(ret) = shared;
185 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
187 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
190 #endif /* USE_ITHREADS */
193 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
196 SV * const sv = sv_newmortal();
198 PERL_ARGS_ASSERT_HV_NOTALLOWED;
200 if (!(flags & HVhek_FREEKEY)) {
201 sv_setpvn(sv, key, klen);
204 /* Need to free saved eventually assign to mortal SV */
205 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
206 sv_usepvn(sv, (char *) key, klen);
208 if (flags & HVhek_UTF8) {
211 Perl_croak(aTHX_ msg, SVfARG(sv));
214 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
220 Stores an SV in a hash. The hash key is specified as C<key> and the
221 absolute value of C<klen> is the length of the key. If C<klen> is
222 negative the key is assumed to be in UTF-8-encoded Unicode. The
223 C<hash> parameter is the precomputed hash value; if it is zero then
224 Perl will compute it.
226 The return value will be
227 NULL if the operation failed or if the value did not need to be actually
228 stored within the hash (as in the case of tied hashes). Otherwise it can
229 be dereferenced to get the original C<SV*>. Note that the caller is
230 responsible for suitably incrementing the reference count of C<val> before
231 the call, and decrementing it if the function returned NULL. Effectively
232 a successful hv_store takes ownership of one reference to C<val>. This is
233 usually what you want; a newly created SV has a reference count of one, so
234 if all your code does is create SVs then store them in a hash, hv_store
235 will own the only reference to the new SV, and your code doesn't need to do
236 anything further to tidy up. hv_store is not implemented as a call to
237 hv_store_ent, and does not create a temporary SV for the key, so if your
238 key data is not already in SV form then use hv_store in preference to
241 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
242 information on how to use this function on tied hashes.
244 =for apidoc hv_store_ent
246 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
247 parameter is the precomputed hash value; if it is zero then Perl will
248 compute it. The return value is the new hash entry so created. It will be
249 NULL if the operation failed or if the value did not need to be actually
250 stored within the hash (as in the case of tied hashes). Otherwise the
251 contents of the return value can be accessed using the C<He?> macros
252 described here. Note that the caller is responsible for suitably
253 incrementing the reference count of C<val> before the call, and
254 decrementing it if the function returned NULL. Effectively a successful
255 hv_store_ent takes ownership of one reference to C<val>. This is
256 usually what you want; a newly created SV has a reference count of one, so
257 if all your code does is create SVs then store them in a hash, hv_store
258 will own the only reference to the new SV, and your code doesn't need to do
259 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
260 unlike C<val> it does not take ownership of it, so maintaining the correct
261 reference count on C<key> is entirely the caller's responsibility. hv_store
262 is not implemented as a call to hv_store_ent, and does not create a temporary
263 SV for the key, so if your key data is not already in SV form then use
264 hv_store in preference to hv_store_ent.
266 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
267 information on how to use this function on tied hashes.
269 =for apidoc hv_exists
271 Returns a boolean indicating whether the specified hash key exists. The
272 absolute value of C<klen> is the length of the key. If C<klen> is
273 negative the key is assumed to be in UTF-8-encoded Unicode.
277 Returns the SV which corresponds to the specified key in the hash.
278 The absolute value of C<klen> is the length of the key. If C<klen> is
279 negative the key is assumed to be in UTF-8-encoded Unicode. If
280 C<lval> is set then the fetch will be part of a store. This means that if
281 there is no value in the hash associated with the given key, then one is
282 created and a pointer to it is returned. The C<SV*> it points to can be
283 assigned to. But always check that the
284 return value is non-null before dereferencing it to an C<SV*>.
286 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
287 information on how to use this function on tied hashes.
289 =for apidoc hv_exists_ent
291 Returns a boolean indicating whether
292 the specified hash key exists. C<hash>
293 can be a valid precomputed hash value, or 0 to ask for it to be
299 /* returns an HE * structure with the all fields set */
300 /* note that hent_val will be a mortal sv for MAGICAL hashes */
302 =for apidoc hv_fetch_ent
304 Returns the hash entry which corresponds to the specified key in the hash.
305 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
306 if you want the function to compute it. IF C<lval> is set then the fetch
307 will be part of a store. Make sure the return value is non-null before
308 accessing it. The return value when C<hv> is a tied hash is a pointer to a
309 static location, so be sure to make a copy of the structure if you need to
312 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
313 information on how to use this function on tied hashes.
318 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
320 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
321 const int action, SV *val, const U32 hash)
326 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
335 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
339 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
340 int flags, int action, SV *val, U32 hash)
349 const int return_svp = action & HV_FETCH_JUST_SV;
353 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
356 assert(SvTYPE(hv) == SVt_PVHV);
358 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
360 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
361 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
362 if (uf->uf_set == NULL) {
363 SV* obj = mg->mg_obj;
366 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
367 ((flags & HVhek_UTF8)
371 mg->mg_obj = keysv; /* pass key */
372 uf->uf_index = action; /* pass action */
373 magic_getuvar(MUTABLE_SV(hv), mg);
374 keysv = mg->mg_obj; /* may have changed */
377 /* If the key may have changed, then we need to invalidate
378 any passed-in computed hash value. */
384 if (flags & HVhek_FREEKEY)
386 key = SvPV_const(keysv, klen);
387 is_utf8 = (SvUTF8(keysv) != 0);
388 if (SvIsCOW_shared_hash(keysv)) {
389 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
391 flags = is_utf8 ? HVhek_UTF8 : 0;
394 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
397 if (action & HV_DELETE) {
398 return (void *) hv_delete_common(hv, keysv, key, klen,
399 flags, action, hash);
402 xhv = (XPVHV*)SvANY(hv);
404 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
405 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
406 || SvGMAGICAL((const SV *)hv))
408 /* FIXME should be able to skimp on the HE/HEK here when
409 HV_FETCH_JUST_SV is true. */
411 keysv = newSVpvn_utf8(key, klen, is_utf8);
413 keysv = newSVsv(keysv);
416 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
418 /* grab a fake HE/HEK pair from the pool or make a new one */
419 entry = PL_hv_fetch_ent_mh;
421 PL_hv_fetch_ent_mh = HeNEXT(entry);
425 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
426 HeKEY_hek(entry) = (HEK*)k;
428 HeNEXT(entry) = NULL;
429 HeSVKEY_set(entry, keysv);
431 sv_upgrade(sv, SVt_PVLV);
433 /* so we can free entry when freeing sv */
434 LvTARG(sv) = MUTABLE_SV(entry);
436 /* XXX remove at some point? */
437 if (flags & HVhek_FREEKEY)
441 return entry ? (void *) &HeVAL(entry) : NULL;
443 return (void *) entry;
445 #ifdef ENV_IS_CASELESS
446 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
448 for (i = 0; i < klen; ++i)
449 if (isLOWER(key[i])) {
450 /* Would be nice if we had a routine to do the
451 copy and upercase in a single pass through. */
452 const char * const nkey = strupr(savepvn(key,klen));
453 /* Note that this fetch is for nkey (the uppercased
454 key) whereas the store is for key (the original) */
455 void *result = hv_common(hv, NULL, nkey, klen,
456 HVhek_FREEKEY, /* free nkey */
457 0 /* non-LVAL fetch */
458 | HV_DISABLE_UVAR_XKEY
461 0 /* compute hash */);
462 if (!result && (action & HV_FETCH_LVALUE)) {
463 /* This call will free key if necessary.
464 Do it this way to encourage compiler to tail
466 result = hv_common(hv, keysv, key, klen, flags,
468 | HV_DISABLE_UVAR_XKEY
472 if (flags & HVhek_FREEKEY)
480 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
481 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
482 || SvGMAGICAL((const SV *)hv)) {
483 /* I don't understand why hv_exists_ent has svret and sv,
484 whereas hv_exists only had one. */
485 SV * const svret = sv_newmortal();
488 if (keysv || is_utf8) {
490 keysv = newSVpvn_utf8(key, klen, TRUE);
492 keysv = newSVsv(keysv);
494 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
496 mg_copy(MUTABLE_SV(hv), sv, key, klen);
498 if (flags & HVhek_FREEKEY)
500 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
501 /* This cast somewhat evil, but I'm merely using NULL/
502 not NULL to return the boolean exists.
503 And I know hv is not NULL. */
504 return SvTRUE(svret) ? (void *)hv : NULL;
506 #ifdef ENV_IS_CASELESS
507 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
508 /* XXX This code isn't UTF8 clean. */
509 char * const keysave = (char * const)key;
510 /* Will need to free this, so set FREEKEY flag. */
511 key = savepvn(key,klen);
512 key = (const char*)strupr((char*)key);
517 if (flags & HVhek_FREEKEY) {
520 flags |= HVhek_FREEKEY;
524 else if (action & HV_FETCH_ISSTORE) {
527 hv_magic_check (hv, &needs_copy, &needs_store);
529 const bool save_taint = TAINT_get;
530 if (keysv || is_utf8) {
532 keysv = newSVpvn_utf8(key, klen, TRUE);
535 TAINT_set(SvTAINTED(keysv));
536 keysv = sv_2mortal(newSVsv(keysv));
537 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
539 mg_copy(MUTABLE_SV(hv), val, key, klen);
542 TAINT_IF(save_taint);
543 #ifdef NO_TAINT_SUPPORT
544 PERL_UNUSED_VAR(save_taint);
547 if (flags & HVhek_FREEKEY)
551 #ifdef ENV_IS_CASELESS
552 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
553 /* XXX This code isn't UTF8 clean. */
554 const char *keysave = key;
555 /* Will need to free this, so set FREEKEY flag. */
556 key = savepvn(key,klen);
557 key = (const char*)strupr((char*)key);
562 if (flags & HVhek_FREEKEY) {
565 flags |= HVhek_FREEKEY;
573 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
574 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
575 || (SvRMAGICAL((const SV *)hv)
576 && mg_find((const SV *)hv, PERL_MAGIC_env))
581 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
583 HvARRAY(hv) = (HE**)array;
585 #ifdef DYNAMIC_ENV_FETCH
586 else if (action & HV_FETCH_ISEXISTS) {
587 /* for an %ENV exists, if we do an insert it's by a recursive
588 store call, so avoid creating HvARRAY(hv) right now. */
592 /* XXX remove at some point? */
593 if (flags & HVhek_FREEKEY)
600 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
601 char * const keysave = (char *)key;
602 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
606 flags &= ~HVhek_UTF8;
607 if (key != keysave) {
608 if (flags & HVhek_FREEKEY)
610 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
611 /* If the caller calculated a hash, it was on the sequence of
612 octets that are the UTF-8 form. We've now changed the sequence
613 of octets stored to that of the equivalent byte representation,
614 so the hash we need is different. */
620 if (keysv && (SvIsCOW_shared_hash(keysv)))
621 hash = SvSHARED_HASH(keysv);
623 PERL_HASH(hash, key, klen);
626 masked_flags = (flags & HVhek_MASK);
628 #ifdef DYNAMIC_ENV_FETCH
629 if (!HvARRAY(hv)) entry = NULL;
633 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
635 for (; entry; entry = HeNEXT(entry)) {
636 if (HeHASH(entry) != hash) /* strings can't be equal */
638 if (HeKLEN(entry) != (I32)klen)
640 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
642 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
645 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
646 if (HeKFLAGS(entry) != masked_flags) {
647 /* We match if HVhek_UTF8 bit in our flags and hash key's
648 match. But if entry was set previously with HVhek_WASUTF8
649 and key now doesn't (or vice versa) then we should change
650 the key's flag, as this is assignment. */
651 if (HvSHAREKEYS(hv)) {
652 /* Need to swap the key we have for a key with the flags we
653 need. As keys are shared we can't just write to the
654 flag, so we share the new one, unshare the old one. */
655 HEK * const new_hek = share_hek_flags(key, klen, hash,
657 unshare_hek (HeKEY_hek(entry));
658 HeKEY_hek(entry) = new_hek;
660 else if (hv == PL_strtab) {
661 /* PL_strtab is usually the only hash without HvSHAREKEYS,
662 so putting this test here is cheap */
663 if (flags & HVhek_FREEKEY)
665 Perl_croak(aTHX_ S_strtab_error,
666 action & HV_FETCH_LVALUE ? "fetch" : "store");
669 HeKFLAGS(entry) = masked_flags;
670 if (masked_flags & HVhek_ENABLEHVKFLAGS)
673 if (HeVAL(entry) == &PL_sv_placeholder) {
674 /* yes, can store into placeholder slot */
675 if (action & HV_FETCH_LVALUE) {
677 /* This preserves behaviour with the old hv_fetch
678 implementation which at this point would bail out
679 with a break; (at "if we find a placeholder, we
680 pretend we haven't found anything")
682 That break mean that if a placeholder were found, it
683 caused a call into hv_store, which in turn would
684 check magic, and if there is no magic end up pretty
685 much back at this point (in hv_store's code). */
688 /* LVAL fetch which actually needs a store. */
690 HvPLACEHOLDERS(hv)--;
693 if (val != &PL_sv_placeholder)
694 HvPLACEHOLDERS(hv)--;
697 } else if (action & HV_FETCH_ISSTORE) {
698 SvREFCNT_dec(HeVAL(entry));
701 } else if (HeVAL(entry) == &PL_sv_placeholder) {
702 /* if we find a placeholder, we pretend we haven't found
706 if (flags & HVhek_FREEKEY)
709 return entry ? (void *) &HeVAL(entry) : NULL;
713 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
714 if (!(action & HV_FETCH_ISSTORE)
715 && SvRMAGICAL((const SV *)hv)
716 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
718 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
720 sv = newSVpvn(env,len);
722 return hv_common(hv, keysv, key, klen, flags,
723 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
729 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
730 hv_notallowed(flags, key, klen,
731 "Attempt to access disallowed key '%"SVf"' in"
732 " a restricted hash");
734 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
735 /* Not doing some form of store, so return failure. */
736 if (flags & HVhek_FREEKEY)
740 if (action & HV_FETCH_LVALUE) {
741 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
743 /* At this point the old hv_fetch code would call to hv_store,
744 which in turn might do some tied magic. So we need to make that
745 magic check happen. */
746 /* gonna assign to this, so it better be there */
747 /* If a fetch-as-store fails on the fetch, then the action is to
748 recurse once into "hv_store". If we didn't do this, then that
749 recursive call would call the key conversion routine again.
750 However, as we replace the original key with the converted
751 key, this would result in a double conversion, which would show
752 up as a bug if the conversion routine is not idempotent.
753 Hence the use of HV_DISABLE_UVAR_XKEY. */
754 return hv_common(hv, keysv, key, klen, flags,
755 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
757 /* XXX Surely that could leak if the fetch-was-store fails?
758 Just like the hv_fetch. */
762 /* Welcome to hv_store... */
765 /* Not sure if we can get here. I think the only case of oentry being
766 NULL is for %ENV with dynamic env fetch. But that should disappear
767 with magic in the previous code. */
770 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
772 HvARRAY(hv) = (HE**)array;
775 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
778 /* share_hek_flags will do the free for us. This might be considered
781 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
782 else if (hv == PL_strtab) {
783 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
784 this test here is cheap */
785 if (flags & HVhek_FREEKEY)
787 Perl_croak(aTHX_ S_strtab_error,
788 action & HV_FETCH_LVALUE ? "fetch" : "store");
790 else /* gotta do the real thing */
791 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
794 if (!*oentry && SvOOK(hv)) {
795 /* initial entry, and aux struct present. */
796 struct xpvhv_aux *const aux = HvAUX(hv);
797 if (aux->xhv_fill_lazy)
798 ++aux->xhv_fill_lazy;
801 #ifdef PERL_HASH_RANDOMIZE_KEYS
802 /* This logic semi-randomizes the insert order in a bucket.
803 * Either we insert into the top, or the slot below the top,
804 * making it harder to see if there is a collision. We also
805 * reset the iterator randomizer if there is one.
807 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
809 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
810 if ( PL_hash_rand_bits & 1 ) {
811 HeNEXT(entry) = HeNEXT(*oentry);
812 HeNEXT(*oentry) = entry;
814 HeNEXT(entry) = *oentry;
820 HeNEXT(entry) = *oentry;
823 #ifdef PERL_HASH_RANDOMIZE_KEYS
825 /* Currently this makes various tests warn in annoying ways.
826 * So Silenced for now. - Yves | bogus end of comment =>* /
827 if (HvAUX(hv)->xhv_riter != -1) {
828 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
829 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
834 if (PL_HASH_RAND_BITS_ENABLED) {
835 if (PL_HASH_RAND_BITS_ENABLED == 1)
836 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
837 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
839 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
843 if (val == &PL_sv_placeholder)
844 HvPLACEHOLDERS(hv)++;
845 if (masked_flags & HVhek_ENABLEHVKFLAGS)
848 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
849 if ( DO_HSPLIT(xhv) ) {
850 const STRLEN oldsize = xhv->xhv_max + 1;
851 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
853 if (items /* hash has placeholders */
854 && !SvREADONLY(hv) /* but is not a restricted hash */) {
855 /* If this hash previously was a "restricted hash" and had
856 placeholders, but the "restricted" flag has been turned off,
857 then the placeholders no longer serve any useful purpose.
858 However, they have the downsides of taking up RAM, and adding
859 extra steps when finding used values. It's safe to clear them
860 at this point, even though Storable rebuilds restricted hashes by
861 putting in all the placeholders (first) before turning on the
862 readonly flag, because Storable always pre-splits the hash.
863 If we're lucky, then we may clear sufficient placeholders to
864 avoid needing to split the hash at all. */
865 clear_placeholders(hv, items);
867 hsplit(hv, oldsize, oldsize * 2);
869 hsplit(hv, oldsize, oldsize * 2);
873 return entry ? (void *) &HeVAL(entry) : NULL;
875 return (void *) entry;
879 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
881 const MAGIC *mg = SvMAGIC(hv);
883 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
888 if (isUPPER(mg->mg_type)) {
890 if (mg->mg_type == PERL_MAGIC_tied) {
891 *needs_store = FALSE;
892 return; /* We've set all there is to set. */
895 mg = mg->mg_moremagic;
900 =for apidoc hv_scalar
902 Evaluates the hash in scalar context and returns the result. Handles magic
903 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)
1166 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1170 char *a = (char*) HvARRAY(hv);
1174 /* already have an HvAUX(hv) so we have to move it */
1176 /* no HvAUX() but array we are going to allocate is large enough
1177 * there is no point in saving the space for the iterator, and
1178 * speeds up later traversals. */
1179 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1182 PERL_ARGS_ASSERT_HSPLIT;
1185 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1186 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1192 #ifdef PERL_HASH_RANDOMIZE_KEYS
1193 /* the idea of this is that we create a "random" value by hashing the address of
1194 * the array, we then use the low bit to decide if we insert at the top, or insert
1195 * second from top. After each such insert we rotate the hashed value. So we can
1196 * use the same hashed value over and over, and in normal build environments use
1197 * very few ops to do so. ROTL32() should produce a single machine operation. */
1198 if (PL_HASH_RAND_BITS_ENABLED) {
1199 if (PL_HASH_RAND_BITS_ENABLED == 1)
1200 PL_hash_rand_bits += ptr_hash((PTRV)a);
1201 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1204 HvARRAY(hv) = (HE**) a;
1205 HvMAX(hv) = newsize - 1;
1206 /* before we zero the newly added memory, we
1207 * need to deal with the aux struct that may be there
1208 * or have been allocated by us*/
1210 struct xpvhv_aux *const dest
1211 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1213 /* alread have an aux, copy the old one in place. */
1214 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1215 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1216 #ifdef PERL_HASH_RANDOMIZE_KEYS
1217 dest->xhv_rand = (U32)PL_hash_rand_bits;
1219 /* For now, just reset the lazy fill counter.
1220 It would be possible to update the counter in the code below
1222 dest->xhv_fill_lazy = 0;
1224 /* no existing aux structure, but we allocated space for one
1225 * so intialize it properly. This unrolls hv_auxinit() a bit,
1226 * since we have to do the realloc anyway. */
1227 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1228 #ifdef PERL_HASH_RANDOMIZE_KEYS
1229 dest->xhv_rand = (U32)PL_hash_rand_bits;
1231 /* this is the "non realloc" part of the hv_auxinit() */
1232 (void)hv_auxinit_internal(dest);
1233 /* Turn on the OOK flag */
1237 /* now we can safely clear the second half */
1238 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1240 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1246 HE **oentry = aep + i;
1249 if (!entry) /* non-existent */
1252 U32 j = (HeHASH(entry) & newsize);
1254 *oentry = HeNEXT(entry);
1255 #ifdef PERL_HASH_RANDOMIZE_KEYS
1256 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1257 * insert to top, otherwise rotate the bucket rand 1 bit,
1258 * and use the new low bit to decide if we insert at top,
1259 * or next from top. IOW, we only rotate on a collision.*/
1260 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1261 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1262 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1263 if (PL_hash_rand_bits & 1) {
1264 HeNEXT(entry)= HeNEXT(aep[j]);
1265 HeNEXT(aep[j])= entry;
1267 /* Note, this is structured in such a way as the optimizer
1268 * should eliminate the duplicated code here and below without
1269 * us needing to explicitly use a goto. */
1270 HeNEXT(entry) = aep[j];
1276 /* see comment above about duplicated code */
1277 HeNEXT(entry) = aep[j];
1282 oentry = &HeNEXT(entry);
1286 } while (i++ < oldsize);
1290 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1293 XPVHV* xhv = (XPVHV*)SvANY(hv);
1294 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1298 PERL_ARGS_ASSERT_HV_KSPLIT;
1300 newsize = (I32) newmax; /* possible truncation here */
1301 if (newsize != newmax || newmax <= oldsize)
1303 while ((newsize & (1 + ~newsize)) != newsize) {
1304 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1306 if (newsize < newmax)
1308 if (newsize < newmax)
1309 return; /* overflow detection */
1311 a = (char *) HvARRAY(hv);
1313 hsplit(hv, oldsize, newsize);
1315 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1316 xhv->xhv_max = --newsize;
1317 HvARRAY(hv) = (HE **) a;
1321 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1322 * as tied hashes could play silly buggers and mess us around. We will
1323 * do the right thing during hv_store() afterwards, but still - Yves */
1324 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1325 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1326 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1327 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1329 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1330 hv_max = hv_max / 2; \
1332 HvMAX(hv) = hv_max; \
1337 Perl_newHVhv(pTHX_ HV *ohv)
1340 HV * const hv = newHV();
1343 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1345 hv_max = HvMAX(ohv);
1347 if (!SvMAGICAL((const SV *)ohv)) {
1348 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1350 const bool shared = !!HvSHAREKEYS(ohv);
1351 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1353 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1356 /* In each bucket... */
1357 for (i = 0; i <= hv_max; i++) {
1359 HE *oent = oents[i];
1366 /* Copy the linked list of entries. */
1367 for (; oent; oent = HeNEXT(oent)) {
1368 const U32 hash = HeHASH(oent);
1369 const char * const key = HeKEY(oent);
1370 const STRLEN len = HeKLEN(oent);
1371 const int flags = HeKFLAGS(oent);
1372 HE * const ent = new_HE();
1373 SV *const val = HeVAL(oent);
1375 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1377 = shared ? share_hek_flags(key, len, hash, flags)
1378 : save_hek_flags(key, len, hash, flags);
1389 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1393 /* Iterate over ohv, copying keys and values one at a time. */
1395 const I32 riter = HvRITER_get(ohv);
1396 HE * const eiter = HvEITER_get(ohv);
1397 STRLEN hv_keys = HvTOTALKEYS(ohv);
1399 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1402 while ((entry = hv_iternext_flags(ohv, 0))) {
1403 SV *val = hv_iterval(ohv,entry);
1404 SV * const keysv = HeSVKEY(entry);
1405 val = SvIMMORTAL(val) ? val : newSVsv(val);
1407 (void)hv_store_ent(hv, keysv, val, 0);
1409 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1410 HeHASH(entry), HeKFLAGS(entry));
1412 HvRITER_set(ohv, riter);
1413 HvEITER_set(ohv, eiter);
1420 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1422 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1423 a pointer to a hash (which may have C<%^H> magic, but should be generally
1424 non-magical), or C<NULL> (interpreted as an empty hash). The content
1425 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1426 added to it. A pointer to the new hash is returned.
1432 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1434 HV * const hv = newHV();
1437 STRLEN hv_max = HvMAX(ohv);
1438 STRLEN hv_keys = HvTOTALKEYS(ohv);
1440 const I32 riter = HvRITER_get(ohv);
1441 HE * const eiter = HvEITER_get(ohv);
1446 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1449 while ((entry = hv_iternext_flags(ohv, 0))) {
1450 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1451 SV *heksv = HeSVKEY(entry);
1452 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1453 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1454 (char *)heksv, HEf_SVKEY);
1455 if (heksv == HeSVKEY(entry))
1456 (void)hv_store_ent(hv, heksv, sv, 0);
1458 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1459 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1460 SvREFCNT_dec_NN(heksv);
1463 HvRITER_set(ohv, riter);
1464 HvEITER_set(ohv, eiter);
1466 SvREFCNT_inc_simple_void_NN(hv);
1469 hv_magic(hv, NULL, PERL_MAGIC_hints);
1472 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1474 /* like hv_free_ent, but returns the SV rather than freeing it */
1476 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1481 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1484 if (HeKLEN(entry) == HEf_SVKEY) {
1485 SvREFCNT_dec(HeKEY_sv(entry));
1486 Safefree(HeKEY_hek(entry));
1488 else if (HvSHAREKEYS(hv))
1489 unshare_hek(HeKEY_hek(entry));
1491 Safefree(HeKEY_hek(entry));
1498 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1503 PERL_ARGS_ASSERT_HV_FREE_ENT;
1507 val = hv_free_ent_ret(hv, entry);
1513 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1517 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1521 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1522 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1523 if (HeKLEN(entry) == HEf_SVKEY) {
1524 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1526 hv_free_ent(hv, entry);
1530 =for apidoc hv_clear
1532 Frees the all the elements of a hash, leaving it empty.
1533 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1535 If any destructors are triggered as a result, the hv itself may
1542 Perl_hv_clear(pTHX_ HV *hv)
1549 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1551 xhv = (XPVHV*)SvANY(hv);
1554 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1555 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1556 /* restricted hash: convert all keys to placeholders */
1558 for (i = 0; i <= xhv->xhv_max; i++) {
1559 HE *entry = (HvARRAY(hv))[i];
1560 for (; entry; entry = HeNEXT(entry)) {
1561 /* not already placeholder */
1562 if (HeVAL(entry) != &PL_sv_placeholder) {
1564 if (SvREADONLY(HeVAL(entry))) {
1565 SV* const keysv = hv_iterkeysv(entry);
1566 Perl_croak_nocontext(
1567 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1570 SvREFCNT_dec_NN(HeVAL(entry));
1572 HeVAL(entry) = &PL_sv_placeholder;
1573 HvPLACEHOLDERS(hv)++;
1580 HvPLACEHOLDERS_set(hv, 0);
1583 mg_clear(MUTABLE_SV(hv));
1585 HvHASKFLAGS_off(hv);
1589 mro_isa_changed_in(hv);
1590 HvEITER_set(hv, NULL);
1596 =for apidoc hv_clear_placeholders
1598 Clears any placeholders from a hash. If a restricted hash has any of its keys
1599 marked as readonly and the key is subsequently deleted, the key is not actually
1600 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1601 it so it will be ignored by future operations such as iterating over the hash,
1602 but will still allow the hash to have a value reassigned to the key at some
1603 future point. This function clears any such placeholder keys from the hash.
1604 See Hash::Util::lock_keys() for an example of its use.
1610 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1613 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1615 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1618 clear_placeholders(hv, items);
1622 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1627 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1634 /* Loop down the linked list heads */
1635 HE **oentry = &(HvARRAY(hv))[i];
1638 while ((entry = *oentry)) {
1639 if (HeVAL(entry) == &PL_sv_placeholder) {
1640 *oentry = HeNEXT(entry);
1641 if (entry == HvEITER_get(hv))
1644 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1645 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1646 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1647 hv_free_ent(hv, entry);
1652 I32 placeholders = HvPLACEHOLDERS_get(hv);
1653 HvTOTALKEYS(hv) -= (IV)placeholders;
1654 /* HvUSEDKEYS expanded */
1655 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1656 HvHASKFLAGS_off(hv);
1657 HvPLACEHOLDERS_set(hv, 0);
1661 oentry = &HeNEXT(entry);
1665 /* You can't get here, hence assertion should always fail. */
1666 assert (items == 0);
1671 S_hfreeentries(pTHX_ HV *hv)
1674 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1677 PERL_ARGS_ASSERT_HFREEENTRIES;
1679 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1685 /* hfree_next_entry()
1686 * For use only by S_hfreeentries() and sv_clear().
1687 * Delete the next available HE from hv and return the associated SV.
1688 * Returns null on empty hash. Nevertheless null is not a reliable
1689 * indicator that the hash is empty, as the deleted entry may have a
1691 * indexp is a pointer to the current index into HvARRAY. The index should
1692 * initially be set to 0. hfree_next_entry() may update it. */
1695 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1697 struct xpvhv_aux *iter;
1701 STRLEN orig_index = *indexp;
1704 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1706 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1707 if ((entry = iter->xhv_eiter)) {
1708 /* the iterator may get resurrected after each
1709 * destructor call, so check each time */
1710 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1712 hv_free_ent(hv, entry);
1713 /* warning: at this point HvARRAY may have been
1714 * re-allocated, HvMAX changed etc */
1716 iter = HvAUX(hv); /* may have been realloced */
1717 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1718 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1719 #ifdef PERL_HASH_RANDOMIZE_KEYS
1720 iter->xhv_last_rand = iter->xhv_rand;
1723 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1724 will actually call HvFILL() on a hash under destruction, so it
1725 seems pointless attempting to track the number of keys remaining.
1726 But if they do, we want to reset it again. */
1727 if (iter->xhv_fill_lazy)
1728 iter->xhv_fill_lazy = 0;
1731 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1734 array = HvARRAY(hv);
1736 while ( ! ((entry = array[*indexp])) ) {
1737 if ((*indexp)++ >= HvMAX(hv))
1739 assert(*indexp != orig_index);
1741 array[*indexp] = HeNEXT(entry);
1742 ((XPVHV*) SvANY(hv))->xhv_keys--;
1744 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1745 && HeVAL(entry) && isGV(HeVAL(entry))
1746 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1749 const char * const key = HePV(entry,klen);
1750 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1751 || (klen == 1 && key[0] == ':')) {
1753 NULL, GvHV(HeVAL(entry)),
1754 (GV *)HeVAL(entry), 0
1758 return hv_free_ent_ret(hv, entry);
1763 =for apidoc hv_undef
1765 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1767 As well as freeing all the elements of the hash (like hv_clear()), this
1768 also frees any auxiliary data and storage associated with the hash.
1770 If any destructors are triggered as a result, the hv itself may
1773 See also L</hv_clear>.
1779 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1787 save = !!SvREFCNT(hv);
1788 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1789 xhv = (XPVHV*)SvANY(hv);
1791 /* The name must be deleted before the call to hfreeeeentries so that
1792 CVs are anonymised properly. But the effective name must be pre-
1793 served until after that call (and only deleted afterwards if the
1794 call originated from sv_clear). For stashes with one name that is
1795 both the canonical name and the effective name, hv_name_set has to
1796 allocate an array for storing the effective name. We can skip that
1797 during global destruction, as it does not matter where the CVs point
1798 if they will be freed anyway. */
1799 /* note that the code following prior to hfreeentries is duplicated
1800 * in sv_clear(), and changes here should be done there too */
1801 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1802 if (PL_stashcache) {
1803 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1804 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1805 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1807 hv_name_set(hv, NULL, 0, 0);
1811 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1815 struct mro_meta *meta;
1818 if (HvENAME_get(hv)) {
1819 if (PL_phase != PERL_PHASE_DESTRUCT)
1820 mro_isa_changed_in(hv);
1821 if (PL_stashcache) {
1822 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1823 HEKf"'\n", HEKfARG(HvENAME_HEK(hv))));
1824 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1828 /* If this call originated from sv_clear, then we must check for
1829 * effective names that need freeing, as well as the usual name. */
1831 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
1832 if (name && PL_stashcache) {
1833 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1834 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1835 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1837 hv_name_set(hv, NULL, 0, flags);
1839 if((meta = HvAUX(hv)->xhv_mro_meta)) {
1840 if (meta->mro_linear_all) {
1841 SvREFCNT_dec_NN(meta->mro_linear_all);
1842 /* mro_linear_current is just acting as a shortcut pointer,
1846 /* Only the current MRO is stored, so this owns the data.
1848 SvREFCNT_dec(meta->mro_linear_current);
1849 SvREFCNT_dec(meta->mro_nextmethod);
1850 SvREFCNT_dec(meta->isa);
1851 SvREFCNT_dec(meta->super);
1853 HvAUX(hv)->xhv_mro_meta = NULL;
1855 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
1856 SvFLAGS(hv) &= ~SVf_OOK;
1859 Safefree(HvARRAY(hv));
1860 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1863 /* if we're freeing the HV, the SvMAGIC field has been reused for
1864 * other purposes, and so there can't be any placeholder magic */
1866 HvPLACEHOLDERS_set(hv, 0);
1869 mg_clear(MUTABLE_SV(hv));
1876 Returns the number of hash buckets that
1877 happen to be in use. This function is
1878 wrapped by the macro C<HvFILL>.
1880 Previously this value was always stored in the HV structure, which created an
1881 overhead on every hash (and pretty much every object) for something that was
1882 rarely used. Now we calculate it on demand the first
1883 time that it is needed, and cache it if that calculation
1884 is going to be costly to repeat. The cached
1885 value is updated by insertions and deletions, but (currently) discarded if
1892 Perl_hv_fill(pTHX_ HV *const hv)
1895 HE **ents = HvARRAY(hv);
1896 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1898 PERL_ARGS_ASSERT_HV_FILL;
1900 /* No keys implies no buckets used.
1901 One key can only possibly mean one bucket used. */
1902 if (HvTOTALKEYS(hv) < 2)
1903 return HvTOTALKEYS(hv);
1906 if (aux && aux->xhv_fill_lazy)
1907 return aux->xhv_fill_lazy;
1911 HE *const *const last = ents + HvMAX(hv);
1912 count = last + 1 - ents;
1917 } while (++ents <= last);
1921 if (aux->xhv_fill_lazy)
1922 assert(aux->xhv_fill_lazy == count);
1924 aux->xhv_fill_lazy = count;
1925 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1926 aux = hv_auxinit(hv);
1927 aux->xhv_fill_lazy = count;
1932 /* hash a pointer to a U32 - Used in the hash traversal randomization
1933 * and bucket order randomization code
1935 * this code was derived from Sereal, which was derived from autobox.
1938 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1941 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1942 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1944 u = (~u) + (u << 18);
1952 * This is one of Bob Jenkins' hash functions for 32-bit integers
1953 * from: http://burtleburtle.net/bob/hash/integer.html
1955 u = (u + 0x7ed55d16) + (u << 12);
1956 u = (u ^ 0xc761c23c) ^ (u >> 19);
1957 u = (u + 0x165667b1) + (u << 5);
1958 u = (u + 0xd3a2646c) ^ (u << 9);
1959 u = (u + 0xfd7046c5) + (u << 3);
1960 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1965 static struct xpvhv_aux*
1966 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
1967 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
1968 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1969 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1970 #ifdef PERL_HASH_RANDOMIZE_KEYS
1971 iter->xhv_last_rand = iter->xhv_rand;
1973 iter->xhv_fill_lazy = 0;
1974 iter->xhv_name_u.xhvnameu_name = 0;
1975 iter->xhv_name_count = 0;
1976 iter->xhv_backreferences = 0;
1977 iter->xhv_mro_meta = NULL;
1978 iter->xhv_aux_flags = 0;
1983 static struct xpvhv_aux*
1984 S_hv_auxinit(pTHX_ HV *hv) {
1985 struct xpvhv_aux *iter;
1988 PERL_ARGS_ASSERT_HV_AUXINIT;
1992 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1993 + sizeof(struct xpvhv_aux), char);
1995 array = (char *) HvARRAY(hv);
1996 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1997 + sizeof(struct xpvhv_aux), char);
1999 HvARRAY(hv) = (HE**)array;
2002 #ifdef PERL_HASH_RANDOMIZE_KEYS
2003 if (PL_HASH_RAND_BITS_ENABLED) {
2004 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2005 if (PL_HASH_RAND_BITS_ENABLED == 1)
2006 PL_hash_rand_bits += ptr_hash((PTRV)array);
2007 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2009 iter->xhv_rand = (U32)PL_hash_rand_bits;
2015 return hv_auxinit_internal(iter);
2019 =for apidoc hv_iterinit
2021 Prepares a starting point to traverse a hash table. Returns the number of
2022 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
2023 currently only meaningful for hashes without tie magic.
2025 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2026 hash buckets that happen to be in use. If you still need that esoteric
2027 value, you can get it through the macro C<HvFILL(hv)>.
2034 Perl_hv_iterinit(pTHX_ HV *hv)
2036 PERL_ARGS_ASSERT_HV_ITERINIT;
2038 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
2041 Perl_croak(aTHX_ "Bad hash");
2044 struct xpvhv_aux * iter = HvAUX(hv);
2045 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2046 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2048 hv_free_ent(hv, entry);
2050 iter = HvAUX(hv); /* may have been reallocated */
2051 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2052 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2053 #ifdef PERL_HASH_RANDOMIZE_KEYS
2054 iter->xhv_last_rand = iter->xhv_rand;
2060 /* used to be xhv->xhv_fill before 5.004_65 */
2061 return HvTOTALKEYS(hv);
2065 Perl_hv_riter_p(pTHX_ HV *hv) {
2066 struct xpvhv_aux *iter;
2068 PERL_ARGS_ASSERT_HV_RITER_P;
2071 Perl_croak(aTHX_ "Bad hash");
2073 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2074 return &(iter->xhv_riter);
2078 Perl_hv_eiter_p(pTHX_ HV *hv) {
2079 struct xpvhv_aux *iter;
2081 PERL_ARGS_ASSERT_HV_EITER_P;
2084 Perl_croak(aTHX_ "Bad hash");
2086 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2087 return &(iter->xhv_eiter);
2091 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2092 struct xpvhv_aux *iter;
2094 PERL_ARGS_ASSERT_HV_RITER_SET;
2097 Perl_croak(aTHX_ "Bad hash");
2105 iter = hv_auxinit(hv);
2107 iter->xhv_riter = riter;
2111 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2112 struct xpvhv_aux *iter;
2114 PERL_ARGS_ASSERT_HV_RAND_SET;
2116 #ifdef PERL_HASH_RANDOMIZE_KEYS
2118 Perl_croak(aTHX_ "Bad hash");
2123 iter = hv_auxinit(hv);
2125 iter->xhv_rand = new_xhv_rand;
2127 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2132 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2133 struct xpvhv_aux *iter;
2135 PERL_ARGS_ASSERT_HV_EITER_SET;
2138 Perl_croak(aTHX_ "Bad hash");
2143 /* 0 is the default so don't go malloc()ing a new structure just to
2148 iter = hv_auxinit(hv);
2150 iter->xhv_eiter = eiter;
2154 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2157 struct xpvhv_aux *iter;
2161 PERL_ARGS_ASSERT_HV_NAME_SET;
2164 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2168 if (iter->xhv_name_u.xhvnameu_name) {
2169 if(iter->xhv_name_count) {
2170 if(flags & HV_NAME_SETALL) {
2171 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2172 HEK **hekp = name + (
2173 iter->xhv_name_count < 0
2174 ? -iter->xhv_name_count
2175 : iter->xhv_name_count
2177 while(hekp-- > name+1)
2178 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2179 /* The first elem may be null. */
2180 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2182 iter = HvAUX(hv); /* may been realloced */
2183 spot = &iter->xhv_name_u.xhvnameu_name;
2184 iter->xhv_name_count = 0;
2187 if(iter->xhv_name_count > 0) {
2188 /* shift some things over */
2190 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2192 spot = iter->xhv_name_u.xhvnameu_names;
2193 spot[iter->xhv_name_count] = spot[1];
2195 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2197 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2198 unshare_hek_or_pvn(*spot, 0, 0, 0);
2202 else if (flags & HV_NAME_SETALL) {
2203 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2204 iter = HvAUX(hv); /* may been realloced */
2205 spot = &iter->xhv_name_u.xhvnameu_name;
2208 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2209 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2210 iter->xhv_name_count = -2;
2211 spot = iter->xhv_name_u.xhvnameu_names;
2212 spot[1] = existing_name;
2215 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2220 iter = hv_auxinit(hv);
2221 spot = &iter->xhv_name_u.xhvnameu_name;
2223 PERL_HASH(hash, name, len);
2224 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2228 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2233 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2234 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2235 if (flags & SVf_UTF8)
2236 return (bytes_cmp_utf8(
2237 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2238 (const U8*)pv, pvlen) == 0);
2240 return (bytes_cmp_utf8(
2241 (const U8*)pv, pvlen,
2242 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2245 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2246 || memEQ(HEK_KEY(hek), pv, pvlen));
2250 =for apidoc hv_ename_add
2252 Adds a name to a stash's internal list of effective names. See
2255 This is called when a stash is assigned to a new location in the symbol
2262 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2265 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2268 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2271 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2273 PERL_HASH(hash, name, len);
2275 if (aux->xhv_name_count) {
2276 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2277 I32 count = aux->xhv_name_count;
2278 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2279 while (hekp-- > xhv_name)
2281 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2282 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2283 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2285 if (hekp == xhv_name && count < 0)
2286 aux->xhv_name_count = -count;
2289 if (count < 0) aux->xhv_name_count--, count = -count;
2290 else aux->xhv_name_count++;
2291 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2292 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2295 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2298 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2299 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2300 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2303 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2304 aux->xhv_name_count = existing_name ? 2 : -2;
2305 *aux->xhv_name_u.xhvnameu_names = existing_name;
2306 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2311 =for apidoc hv_ename_delete
2313 Removes a name from a stash's internal list of effective names. If this is
2314 the name returned by C<HvENAME>, then another name in the list will take
2315 its place (C<HvENAME> will use it).
2317 This is called when a stash is deleted from the symbol table.
2323 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2326 struct xpvhv_aux *aux;
2328 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2331 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2333 if (!SvOOK(hv)) return;
2336 if (!aux->xhv_name_u.xhvnameu_name) return;
2338 if (aux->xhv_name_count) {
2339 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2340 I32 const count = aux->xhv_name_count;
2341 HEK **victim = namep + (count < 0 ? -count : count);
2342 while (victim-- > namep + 1)
2344 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2345 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2346 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2348 unshare_hek_or_pvn(*victim, 0, 0, 0);
2349 aux = HvAUX(hv); /* may been realloced */
2350 if (count < 0) ++aux->xhv_name_count;
2351 else --aux->xhv_name_count;
2353 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2355 ) { /* if there are none left */
2357 aux->xhv_name_u.xhvnameu_names = NULL;
2358 aux->xhv_name_count = 0;
2361 /* Move the last one back to fill the empty slot. It
2362 does not matter what order they are in. */
2363 *victim = *(namep + (count < 0 ? -count : count) - 1);
2368 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2369 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2370 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2372 aux->xhv_name_count = -count;
2376 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2377 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2378 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2379 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2381 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2382 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2383 *aux->xhv_name_u.xhvnameu_names = namehek;
2384 aux->xhv_name_count = -1;
2389 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2390 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2392 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2393 PERL_UNUSED_CONTEXT;
2395 return &(iter->xhv_backreferences);
2399 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2402 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2407 av = HvAUX(hv)->xhv_backreferences;
2410 HvAUX(hv)->xhv_backreferences = 0;
2411 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2412 if (SvTYPE(av) == SVt_PVAV)
2413 SvREFCNT_dec_NN(av);
2418 hv_iternext is implemented as a macro in hv.h
2420 =for apidoc hv_iternext
2422 Returns entries from a hash iterator. See C<hv_iterinit>.
2424 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2425 iterator currently points to, without losing your place or invalidating your
2426 iterator. Note that in this case the current entry is deleted from the hash
2427 with your iterator holding the last reference to it. Your iterator is flagged
2428 to free the entry on the next call to C<hv_iternext>, so you must not discard
2429 your iterator immediately else the entry will leak - call C<hv_iternext> to
2430 trigger the resource deallocation.
2432 =for apidoc hv_iternext_flags
2434 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2435 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2436 set the placeholders keys (for restricted hashes) will be returned in addition
2437 to normal keys. By default placeholders are automatically skipped over.
2438 Currently a placeholder is implemented with a value that is
2439 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2440 restricted hashes may change, and the implementation currently is
2441 insufficiently abstracted for any change to be tidy.
2447 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2454 struct xpvhv_aux *iter;
2456 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2459 Perl_croak(aTHX_ "Bad hash");
2461 xhv = (XPVHV*)SvANY(hv);
2464 /* Too many things (well, pp_each at least) merrily assume that you can
2465 call hv_iternext without calling hv_iterinit, so we'll have to deal
2471 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2472 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2473 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2474 SV * const key = sv_newmortal();
2476 sv_setsv(key, HeSVKEY_force(entry));
2477 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2478 HeSVKEY_set(entry, NULL);
2484 /* one HE per MAGICAL hash */
2485 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2486 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2488 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2490 HeKEY_hek(entry) = hek;
2491 HeKLEN(entry) = HEf_SVKEY;
2493 magic_nextpack(MUTABLE_SV(hv),mg,key);
2495 /* force key to stay around until next time */
2496 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2497 return entry; /* beware, hent_val is not set */
2499 SvREFCNT_dec(HeVAL(entry));
2500 Safefree(HeKEY_hek(entry));
2502 iter = HvAUX(hv); /* may been realloced */
2503 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2508 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2509 if (!entry && SvRMAGICAL((const SV *)hv)
2510 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2513 /* The prime_env_iter() on VMS just loaded up new hash values
2514 * so the iteration count needs to be reset back to the beginning
2518 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2523 /* hv_iterinit now ensures this. */
2524 assert (HvARRAY(hv));
2526 /* At start of hash, entry is NULL. */
2529 entry = HeNEXT(entry);
2530 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2532 * Skip past any placeholders -- don't want to include them in
2535 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2536 entry = HeNEXT(entry);
2541 #ifdef PERL_HASH_RANDOMIZE_KEYS
2542 if (iter->xhv_last_rand != iter->xhv_rand) {
2543 if (iter->xhv_riter != -1) {
2544 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2545 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2549 iter = HvAUX(hv); /* may been realloced */
2550 iter->xhv_last_rand = iter->xhv_rand;
2554 /* Skip the entire loop if the hash is empty. */
2555 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2556 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2558 /* OK. Come to the end of the current list. Grab the next one. */
2560 iter->xhv_riter++; /* HvRITER(hv)++ */
2561 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2562 /* There is no next one. End of the hash. */
2563 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2564 #ifdef PERL_HASH_RANDOMIZE_KEYS
2565 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2569 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2571 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2572 /* If we have an entry, but it's a placeholder, don't count it.
2574 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2575 entry = HeNEXT(entry);
2577 /* Will loop again if this linked list starts NULL
2578 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2579 or if we run through it and find only placeholders. */
2583 iter->xhv_riter = -1;
2584 #ifdef PERL_HASH_RANDOMIZE_KEYS
2585 iter->xhv_last_rand = iter->xhv_rand;
2589 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2591 hv_free_ent(hv, oldentry);
2594 iter = HvAUX(hv); /* may been realloced */
2595 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2600 =for apidoc hv_iterkey
2602 Returns the key from the current position of the hash iterator. See
2609 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2611 PERL_ARGS_ASSERT_HV_ITERKEY;
2613 if (HeKLEN(entry) == HEf_SVKEY) {
2615 char * const p = SvPV(HeKEY_sv(entry), len);
2620 *retlen = HeKLEN(entry);
2621 return HeKEY(entry);
2625 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2627 =for apidoc hv_iterkeysv
2629 Returns the key as an C<SV*> from the current position of the hash
2630 iterator. The return value will always be a mortal copy of the key. Also
2637 Perl_hv_iterkeysv(pTHX_ HE *entry)
2639 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2641 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2645 =for apidoc hv_iterval
2647 Returns the value from the current position of the hash iterator. See
2654 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2656 PERL_ARGS_ASSERT_HV_ITERVAL;
2658 if (SvRMAGICAL(hv)) {
2659 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2660 SV* const sv = sv_newmortal();
2661 if (HeKLEN(entry) == HEf_SVKEY)
2662 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2664 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2668 return HeVAL(entry);
2672 =for apidoc hv_iternextsv
2674 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2681 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2683 HE * const he = hv_iternext_flags(hv, 0);
2685 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2689 *key = hv_iterkey(he, retlen);
2690 return hv_iterval(hv, he);
2697 =for apidoc hv_magic
2699 Adds magic to a hash. See C<sv_magic>.
2704 /* possibly free a shared string if no one has access to it
2705 * len and hash must both be valid for str.
2708 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2710 unshare_hek_or_pvn (NULL, str, len, hash);
2715 Perl_unshare_hek(pTHX_ HEK *hek)
2718 unshare_hek_or_pvn(hek, NULL, 0, 0);
2721 /* possibly free a shared string if no one has access to it
2722 hek if non-NULL takes priority over the other 3, else str, len and hash
2723 are used. If so, len and hash must both be valid for str.
2726 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2732 bool is_utf8 = FALSE;
2734 const char * const save = str;
2735 struct shared_he *he = NULL;
2738 /* Find the shared he which is just before us in memory. */
2739 he = (struct shared_he *)(((char *)hek)
2740 - STRUCT_OFFSET(struct shared_he,
2743 /* Assert that the caller passed us a genuine (or at least consistent)
2745 assert (he->shared_he_he.hent_hek == hek);
2747 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2748 --he->shared_he_he.he_valu.hent_refcount;
2752 hash = HEK_HASH(hek);
2753 } else if (len < 0) {
2754 STRLEN tmplen = -len;
2756 /* See the note in hv_fetch(). --jhi */
2757 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2760 k_flags = HVhek_UTF8;
2762 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2765 /* what follows was the moral equivalent of:
2766 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2768 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2770 xhv = (XPVHV*)SvANY(PL_strtab);
2771 /* assert(xhv_array != 0) */
2772 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2774 const HE *const he_he = &(he->shared_he_he);
2775 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2780 const int flags_masked = k_flags & HVhek_MASK;
2781 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2782 if (HeHASH(entry) != hash) /* strings can't be equal */
2784 if (HeKLEN(entry) != len)
2786 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2788 if (HeKFLAGS(entry) != flags_masked)
2795 if (--entry->he_valu.hent_refcount == 0) {
2796 *oentry = HeNEXT(entry);
2798 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2803 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2804 "Attempt to free nonexistent shared string '%s'%s"
2806 hek ? HEK_KEY(hek) : str,
2807 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2808 if (k_flags & HVhek_FREEKEY)
2812 /* get a (constant) string ptr from the global string table
2813 * string will get added if it is not already there.
2814 * len and hash must both be valid for str.
2817 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2819 bool is_utf8 = FALSE;
2821 const char * const save = str;
2823 PERL_ARGS_ASSERT_SHARE_HEK;
2826 STRLEN tmplen = -len;
2828 /* See the note in hv_fetch(). --jhi */
2829 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2831 /* If we were able to downgrade here, then than means that we were passed
2832 in a key which only had chars 0-255, but was utf8 encoded. */
2835 /* If we found we were able to downgrade the string to bytes, then
2836 we should flag that it needs upgrading on keys or each. Also flag
2837 that we need share_hek_flags to free the string. */
2840 PERL_HASH(hash, str, len);
2841 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2845 return share_hek_flags (str, len, hash, flags);
2849 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2853 const int flags_masked = flags & HVhek_MASK;
2854 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2855 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2857 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2859 /* what follows is the moral equivalent of:
2861 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2862 hv_store(PL_strtab, str, len, NULL, hash);
2864 Can't rehash the shared string table, so not sure if it's worth
2865 counting the number of entries in the linked list
2868 /* assert(xhv_array != 0) */
2869 entry = (HvARRAY(PL_strtab))[hindex];
2870 for (;entry; entry = HeNEXT(entry)) {
2871 if (HeHASH(entry) != hash) /* strings can't be equal */
2873 if (HeKLEN(entry) != len)
2875 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2877 if (HeKFLAGS(entry) != flags_masked)
2883 /* What used to be head of the list.
2884 If this is NULL, then we're the first entry for this slot, which
2885 means we need to increate fill. */
2886 struct shared_he *new_entry;
2889 HE **const head = &HvARRAY(PL_strtab)[hindex];
2890 HE *const next = *head;
2892 /* We don't actually store a HE from the arena and a regular HEK.
2893 Instead we allocate one chunk of memory big enough for both,
2894 and put the HEK straight after the HE. This way we can find the
2895 HE directly from the HEK.
2898 Newx(k, STRUCT_OFFSET(struct shared_he,
2899 shared_he_hek.hek_key[0]) + len + 2, char);
2900 new_entry = (struct shared_he *)k;
2901 entry = &(new_entry->shared_he_he);
2902 hek = &(new_entry->shared_he_hek);
2904 Copy(str, HEK_KEY(hek), len, char);
2905 HEK_KEY(hek)[len] = 0;
2907 HEK_HASH(hek) = hash;
2908 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2910 /* Still "point" to the HEK, so that other code need not know what
2912 HeKEY_hek(entry) = hek;
2913 entry->he_valu.hent_refcount = 0;
2914 HeNEXT(entry) = next;
2917 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2918 if (!next) { /* initial entry? */
2919 } else if ( DO_HSPLIT(xhv) ) {
2920 const STRLEN oldsize = xhv->xhv_max + 1;
2921 hsplit(PL_strtab, oldsize, oldsize * 2);
2925 ++entry->he_valu.hent_refcount;
2927 if (flags & HVhek_FREEKEY)
2930 return HeKEY_hek(entry);
2934 Perl_hv_placeholders_p(pTHX_ HV *hv)
2937 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2939 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2942 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2945 Perl_die(aTHX_ "panic: hv_placeholders_p");
2948 return &(mg->mg_len);
2953 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2956 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2958 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2960 return mg ? mg->mg_len : 0;
2964 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2967 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2969 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2974 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2975 Perl_die(aTHX_ "panic: hv_placeholders_set");
2977 /* else we don't need to add magic to record 0 placeholders. */
2981 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2986 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2988 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2993 value = &PL_sv_placeholder;
2996 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2999 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3002 case HVrhek_PV_UTF8:
3003 /* Create a string SV that directly points to the bytes in our
3005 value = newSV_type(SVt_PV);
3006 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3007 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3008 /* This stops anything trying to free it */
3009 SvLEN_set(value, 0);
3011 SvREADONLY_on(value);
3012 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3016 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
3017 (UV)he->refcounted_he_data[0]);
3023 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
3025 Generates and returns a C<HV *> representing the content of a
3026 C<refcounted_he> chain.
3027 I<flags> is currently unused and must be zero.
3032 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3036 U32 placeholders, max;
3039 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3042 /* We could chase the chain once to get an idea of the number of keys,
3043 and call ksplit. But for now we'll make a potentially inefficient
3044 hash with only 8 entries in its array. */
3049 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3050 HvARRAY(hv) = (HE**)array;
3056 U32 hash = chain->refcounted_he_hash;
3058 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3060 HE **oentry = &((HvARRAY(hv))[hash & max]);
3061 HE *entry = *oentry;
3064 for (; entry; entry = HeNEXT(entry)) {
3065 if (HeHASH(entry) == hash) {
3066 /* We might have a duplicate key here. If so, entry is older
3067 than the key we've already put in the hash, so if they are
3068 the same, skip adding entry. */
3070 const STRLEN klen = HeKLEN(entry);
3071 const char *const key = HeKEY(entry);
3072 if (klen == chain->refcounted_he_keylen
3073 && (!!HeKUTF8(entry)
3074 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3075 && memEQ(key, REF_HE_KEY(chain), klen))
3078 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3080 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3081 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3082 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3093 = share_hek_flags(REF_HE_KEY(chain),
3094 chain->refcounted_he_keylen,
3095 chain->refcounted_he_hash,
3096 (chain->refcounted_he_data[0]
3097 & (HVhek_UTF8|HVhek_WASUTF8)));
3099 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3101 value = refcounted_he_value(chain);
3102 if (value == &PL_sv_placeholder)
3104 HeVAL(entry) = value;
3106 /* Link it into the chain. */
3107 HeNEXT(entry) = *oentry;
3113 chain = chain->refcounted_he_next;
3117 clear_placeholders(hv, placeholders);
3118 HvTOTALKEYS(hv) -= placeholders;
3121 /* We could check in the loop to see if we encounter any keys with key
3122 flags, but it's probably not worth it, as this per-hash flag is only
3123 really meant as an optimisation for things like Storable. */
3125 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3131 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3133 Search along a C<refcounted_he> chain for an entry with the key specified
3134 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3135 bit set, the key octets are interpreted as UTF-8, otherwise they
3136 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3137 string, or zero if it has not been precomputed. Returns a mortal scalar
3138 representing the value associated with the key, or C<&PL_sv_placeholder>
3139 if there is no value associated with the key.
3145 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3146 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3150 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3152 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3153 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3156 return &PL_sv_placeholder;
3157 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3158 /* For searching purposes, canonicalise to Latin-1 where possible. */
3159 const char *keyend = keypv + keylen, *p;
3160 STRLEN nonascii_count = 0;
3161 for (p = keypv; p != keyend; p++) {
3162 if (! UTF8_IS_INVARIANT(*p)) {
3163 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3164 goto canonicalised_key;
3170 if (nonascii_count) {
3172 const char *p = keypv, *keyend = keypv + keylen;
3173 keylen -= nonascii_count;
3174 Newx(q, keylen, char);
3177 for (; p != keyend; p++, q++) {
3179 if (UTF8_IS_INVARIANT(c)) {
3184 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3188 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3189 canonicalised_key: ;
3191 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3193 PERL_HASH(hash, keypv, keylen);
3195 for (; chain; chain = chain->refcounted_he_next) {
3198 hash == chain->refcounted_he_hash &&
3199 keylen == chain->refcounted_he_keylen &&
3200 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3201 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3203 hash == HEK_HASH(chain->refcounted_he_hek) &&
3204 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3205 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3206 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3209 if (flags & REFCOUNTED_HE_EXISTS)
3210 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3212 ? NULL : &PL_sv_yes;
3213 return sv_2mortal(refcounted_he_value(chain));
3216 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3220 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3222 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3223 instead of a string/length pair.
3229 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3230 const char *key, U32 hash, U32 flags)
3232 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3233 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3237 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3239 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3246 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3247 SV *key, U32 hash, U32 flags)
3251 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3252 if (flags & REFCOUNTED_HE_KEY_UTF8)
3253 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3255 keypv = SvPV_const(key, keylen);
3257 flags |= REFCOUNTED_HE_KEY_UTF8;
3258 if (!hash && SvIsCOW_shared_hash(key))
3259 hash = SvSHARED_HASH(key);
3260 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3264 =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
3266 Creates a new C<refcounted_he>. This consists of a single key/value
3267 pair and a reference to an existing C<refcounted_he> chain (which may
3268 be empty), and thus forms a longer chain. When using the longer chain,
3269 the new key/value pair takes precedence over any entry for the same key
3270 further along the chain.
3272 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3273 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3274 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3275 a precomputed hash of the key string, or zero if it has not been
3278 I<value> is the scalar value to store for this key. I<value> is copied
3279 by this function, which thus does not take ownership of any reference
3280 to it, and later changes to the scalar will not be reflected in the
3281 value visible in the C<refcounted_he>. Complex types of scalar will not
3282 be stored with referential integrity, but will be coerced to strings.
3283 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3284 value is to be associated with the key; this, as with any non-null value,
3285 takes precedence over the existence of a value for the key further along
3288 I<parent> points to the rest of the C<refcounted_he> chain to be
3289 attached to the new C<refcounted_he>. This function takes ownership
3290 of one reference to I<parent>, and returns one reference to the new
3296 struct refcounted_he *
3297 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3298 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3301 STRLEN value_len = 0;
3302 const char *value_p = NULL;
3306 STRLEN key_offset = 1;
3307 struct refcounted_he *he;
3308 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3310 if (!value || value == &PL_sv_placeholder) {
3311 value_type = HVrhek_delete;
3312 } else if (SvPOK(value)) {
3313 value_type = HVrhek_PV;
3314 } else if (SvIOK(value)) {
3315 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3316 } else if (!SvOK(value)) {
3317 value_type = HVrhek_undef;
3319 value_type = HVrhek_PV;
3321 is_pv = value_type == HVrhek_PV;
3323 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3324 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3325 value_p = SvPV_const(value, value_len);
3327 value_type = HVrhek_PV_UTF8;
3328 key_offset = value_len + 2;
3330 hekflags = value_type;
3332 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3333 /* Canonicalise to Latin-1 where possible. */
3334 const char *keyend = keypv + keylen, *p;
3335 STRLEN nonascii_count = 0;
3336 for (p = keypv; p != keyend; p++) {
3337 if (! UTF8_IS_INVARIANT(*p)) {
3338 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3339 goto canonicalised_key;
3345 if (nonascii_count) {
3347 const char *p = keypv, *keyend = keypv + keylen;
3348 keylen -= nonascii_count;
3349 Newx(q, keylen, char);
3352 for (; p != keyend; p++, q++) {
3354 if (UTF8_IS_INVARIANT(c)) {
3359 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3363 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3364 canonicalised_key: ;
3366 if (flags & REFCOUNTED_HE_KEY_UTF8)
3367 hekflags |= HVhek_UTF8;
3369 PERL_HASH(hash, keypv, keylen);
3372 he = (struct refcounted_he*)
3373 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3377 he = (struct refcounted_he*)
3378 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3382 he->refcounted_he_next = parent;
3385 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3386 he->refcounted_he_val.refcounted_he_u_len = value_len;
3387 } else if (value_type == HVrhek_IV) {
3388 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3389 } else if (value_type == HVrhek_UV) {
3390 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3394 he->refcounted_he_hash = hash;
3395 he->refcounted_he_keylen = keylen;
3396 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3398 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3401 he->refcounted_he_data[0] = hekflags;
3402 he->refcounted_he_refcnt = 1;
3408 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3410 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3411 of a string/length pair.
3416 struct refcounted_he *
3417 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3418 const char *key, U32 hash, SV *value, U32 flags)
3420 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3421 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3425 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3427 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3433 struct refcounted_he *
3434 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3435 SV *key, U32 hash, SV *value, U32 flags)
3439 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3440 if (flags & REFCOUNTED_HE_KEY_UTF8)
3441 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3443 keypv = SvPV_const(key, keylen);
3445 flags |= REFCOUNTED_HE_KEY_UTF8;
3446 if (!hash && SvIsCOW_shared_hash(key))
3447 hash = SvSHARED_HASH(key);
3448 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3452 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3454 Decrements the reference count of a C<refcounted_he> by one. If the
3455 reference count reaches zero the structure's memory is freed, which
3456 (recursively) causes a reduction of its parent C<refcounted_he>'s
3457 reference count. It is safe to pass a null pointer to this function:
3458 no action occurs in this case.
3464 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3466 PERL_UNUSED_CONTEXT;
3469 struct refcounted_he *copy;
3473 new_count = --he->refcounted_he_refcnt;
3474 HINTS_REFCNT_UNLOCK;
3480 #ifndef USE_ITHREADS
3481 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3484 he = he->refcounted_he_next;
3485 PerlMemShared_free(copy);
3490 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3492 Increment the reference count of a C<refcounted_he>. The pointer to the
3493 C<refcounted_he> is also returned. It is safe to pass a null pointer
3494 to this function: no action occurs and a null pointer is returned.
3499 struct refcounted_he *
3500 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3503 PERL_UNUSED_CONTEXT;
3506 he->refcounted_he_refcnt++;
3507 HINTS_REFCNT_UNLOCK;
3513 =for apidoc cop_fetch_label
3515 Returns the label attached to a cop.
3516 The flags pointer may be set to C<SVf_UTF8> or 0.
3521 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3524 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3525 struct refcounted_he *const chain = cop->cop_hints_hash;
3527 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3528 PERL_UNUSED_CONTEXT;
3533 if (chain->refcounted_he_keylen != 1)
3535 if (*REF_HE_KEY(chain) != ':')
3538 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3540 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3543 /* Stop anyone trying to really mess us up by adding their own value for
3545 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3546 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3550 *len = chain->refcounted_he_val.refcounted_he_u_len;
3552 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3553 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3555 return chain->refcounted_he_data + 1;
3559 =for apidoc cop_store_label
3561 Save a label into a C<cop_hints_hash>.
3562 You need to set flags to C<SVf_UTF8>
3569 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3573 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3575 if (flags & ~(SVf_UTF8))
3576 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3578 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3579 if (flags & SVf_UTF8)
3582 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3586 =for apidoc hv_assert
3588 Check that a hash is in an internally consistent state.
3596 Perl_hv_assert(pTHX_ HV *hv)
3601 int placeholders = 0;
3604 const I32 riter = HvRITER_get(hv);
3605 HE *eiter = HvEITER_get(hv);
3607 PERL_ARGS_ASSERT_HV_ASSERT;
3609 (void)hv_iterinit(hv);
3611 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3612 /* sanity check the values */
3613 if (HeVAL(entry) == &PL_sv_placeholder)
3617 /* sanity check the keys */
3618 if (HeSVKEY(entry)) {
3619 NOOP; /* Don't know what to check on SV keys. */
3620 } else if (HeKUTF8(entry)) {
3622 if (HeKWASUTF8(entry)) {
3623 PerlIO_printf(Perl_debug_log,
3624 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3625 (int) HeKLEN(entry), HeKEY(entry));
3628 } else if (HeKWASUTF8(entry))
3631 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3632 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3633 const int nhashkeys = HvUSEDKEYS(hv);
3634 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3636 if (nhashkeys != real) {
3637 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3640 if (nhashplaceholders != placeholders) {
3641 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3645 if (withflags && ! HvHASKFLAGS(hv)) {
3646 PerlIO_printf(Perl_debug_log,
3647 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3652 sv_dump(MUTABLE_SV(hv));
3654 HvRITER_set(hv, riter); /* Restore hash iterator state */
3655 HvEITER_set(hv, eiter);
3662 * c-indentation-style: bsd
3664 * indent-tabs-mode: nil
3667 * ex: set ts=8 sts=4 sw=4 et: