3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
21 A HV structure represents a Perl hash. It consists mainly of an array
22 of pointers, each of which points to a linked list of HE structures. The
23 array is indexed by the hash function of the key, so each linked list
24 represents all the hash entries with the same hash value. Each HE contains
25 a pointer to the actual value, plus a pointer to a HEK structure which
26 holds the key and hash value.
34 #define PERL_HASH_INTERNAL_ACCESS
37 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
38 #define HV_FILL_THRESHOLD 31
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
45 #define new_HE() (HE*)safemalloc(sizeof(HE))
46 #define del_HE(p) safefree((char*)p)
54 void ** const root = &PL_body_roots[HE_SVSLOT];
57 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
64 #define new_HE() new_he()
67 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
68 PL_body_roots[HE_SVSLOT] = p; \
76 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
78 const int flags_masked = flags & HVhek_MASK;
82 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
84 Newx(k, HEK_BASESIZE + len + 2, char);
86 Copy(str, HEK_KEY(hek), len, char);
87 HEK_KEY(hek)[len] = 0;
90 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
92 if (flags & HVhek_FREEKEY)
97 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
101 Perl_free_tied_hv_pool(pTHX)
103 HE *he = PL_hv_fetch_ent_mh;
106 Safefree(HeKEY_hek(he));
110 PL_hv_fetch_ent_mh = NULL;
113 #if defined(USE_ITHREADS)
115 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
119 PERL_ARGS_ASSERT_HEK_DUP;
120 PERL_UNUSED_ARG(param);
125 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
127 /* We already shared this hash key. */
128 (void)share_hek_hek(shared);
132 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
133 HEK_HASH(source), HEK_FLAGS(source));
134 ptr_table_store(PL_ptr_table, source, shared);
140 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
144 PERL_ARGS_ASSERT_HE_DUP;
148 /* look for it in the table first */
149 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
153 /* create anew and remember what it is */
155 ptr_table_store(PL_ptr_table, e, ret);
157 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
158 if (HeKLEN(e) == HEf_SVKEY) {
160 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
161 HeKEY_hek(ret) = (HEK*)k;
162 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
165 /* This is hek_dup inlined, which seems to be important for speed
167 HEK * const source = HeKEY_hek(e);
168 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
171 /* We already shared this hash key. */
172 (void)share_hek_hek(shared);
176 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
177 HEK_HASH(source), HEK_FLAGS(source));
178 ptr_table_store(PL_ptr_table, source, shared);
180 HeKEY_hek(ret) = shared;
183 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
185 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
188 #endif /* USE_ITHREADS */
191 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
194 SV * const sv = sv_newmortal();
196 PERL_ARGS_ASSERT_HV_NOTALLOWED;
198 if (!(flags & HVhek_FREEKEY)) {
199 sv_setpvn(sv, key, klen);
202 /* Need to free saved eventually assign to mortal SV */
203 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
204 sv_usepvn(sv, (char *) key, klen);
206 if (flags & HVhek_UTF8) {
209 Perl_croak(aTHX_ msg, SVfARG(sv));
212 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
218 Stores an SV in a hash. The hash key is specified as C<key> and the
219 absolute value of C<klen> is the length of the key. If C<klen> is
220 negative the key is assumed to be in UTF-8-encoded Unicode. The
221 C<hash> parameter is the precomputed hash value; if it is zero then
222 Perl will compute it.
224 The return value will be
225 NULL if the operation failed or if the value did not need to be actually
226 stored within the hash (as in the case of tied hashes). Otherwise it can
227 be dereferenced to get the original C<SV*>. Note that the caller is
228 responsible for suitably incrementing the reference count of C<val> before
229 the call, and decrementing it if the function returned NULL. Effectively
230 a successful hv_store takes ownership of one reference to C<val>. This is
231 usually what you want; a newly created SV has a reference count of one, so
232 if all your code does is create SVs then store them in a hash, hv_store
233 will own the only reference to the new SV, and your code doesn't need to do
234 anything further to tidy up. hv_store is not implemented as a call to
235 hv_store_ent, and does not create a temporary SV for the key, so if your
236 key data is not already in SV form then use hv_store in preference to
239 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
240 information on how to use this function on tied hashes.
242 =for apidoc hv_store_ent
244 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
245 parameter is the precomputed hash value; if it is zero then Perl will
246 compute it. The return value is the new hash entry so created. It will be
247 NULL if the operation failed or if the value did not need to be actually
248 stored within the hash (as in the case of tied hashes). Otherwise the
249 contents of the return value can be accessed using the C<He?> macros
250 described here. Note that the caller is responsible for suitably
251 incrementing the reference count of C<val> before the call, and
252 decrementing it if the function returned NULL. Effectively a successful
253 hv_store_ent takes ownership of one reference to C<val>. This is
254 usually what you want; a newly created SV has a reference count of one, so
255 if all your code does is create SVs then store them in a hash, hv_store
256 will own the only reference to the new SV, and your code doesn't need to do
257 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
258 unlike C<val> it does not take ownership of it, so maintaining the correct
259 reference count on C<key> is entirely the caller's responsibility. hv_store
260 is not implemented as a call to hv_store_ent, and does not create a temporary
261 SV for the key, so if your key data is not already in SV form then use
262 hv_store in preference to hv_store_ent.
264 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
265 information on how to use this function on tied hashes.
267 =for apidoc hv_exists
269 Returns a boolean indicating whether the specified hash key exists. The
270 absolute value of C<klen> is the length of the key. If C<klen> is
271 negative the key is assumed to be in UTF-8-encoded Unicode.
275 Returns the SV which corresponds to the specified key in the hash.
276 The absolute value of C<klen> is the length of the key. If C<klen> is
277 negative the key is assumed to be in UTF-8-encoded Unicode. If
278 C<lval> is set then the fetch will be part of a store. This means that if
279 there is no value in the hash associated with the given key, then one is
280 created and a pointer to it is returned. The C<SV*> it points to can be
281 assigned to. But always check that the
282 return value is non-null before dereferencing it to an C<SV*>.
284 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
285 information on how to use this function on tied hashes.
287 =for apidoc hv_exists_ent
289 Returns a boolean indicating whether
290 the specified hash key exists. C<hash>
291 can be a valid precomputed hash value, or 0 to ask for it to be
297 /* returns an HE * structure with the all fields set */
298 /* note that hent_val will be a mortal sv for MAGICAL hashes */
300 =for apidoc hv_fetch_ent
302 Returns the hash entry which corresponds to the specified key in the hash.
303 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
304 if you want the function to compute it. IF C<lval> is set then the fetch
305 will be part of a store. Make sure the return value is non-null before
306 accessing it. The return value when C<hv> is a tied hash is a pointer to a
307 static location, so be sure to make a copy of the structure if you need to
310 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
311 information on how to use this function on tied hashes.
316 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
318 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
319 const int action, SV *val, const U32 hash)
324 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
333 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
337 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
338 int flags, int action, SV *val, U32 hash)
347 const int return_svp = action & HV_FETCH_JUST_SV;
348 HEK *keysv_hek = NULL;
352 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
355 assert(SvTYPE(hv) == SVt_PVHV);
357 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
359 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
360 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
361 if (uf->uf_set == NULL) {
362 SV* obj = mg->mg_obj;
365 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
366 ((flags & HVhek_UTF8)
370 mg->mg_obj = keysv; /* pass key */
371 uf->uf_index = action; /* pass action */
372 magic_getuvar(MUTABLE_SV(hv), mg);
373 keysv = mg->mg_obj; /* may have changed */
376 /* If the key may have changed, then we need to invalidate
377 any passed-in computed hash value. */
383 if (flags & HVhek_FREEKEY)
385 key = SvPV_const(keysv, klen);
386 is_utf8 = (SvUTF8(keysv) != 0);
387 if (SvIsCOW_shared_hash(keysv)) {
388 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
390 flags = is_utf8 ? HVhek_UTF8 : 0;
393 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
396 if (action & HV_DELETE) {
397 return (void *) hv_delete_common(hv, keysv, key, klen,
398 flags, action, hash);
401 xhv = (XPVHV*)SvANY(hv);
403 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
404 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
405 || SvGMAGICAL((const SV *)hv))
407 /* FIXME should be able to skimp on the HE/HEK here when
408 HV_FETCH_JUST_SV is true. */
410 keysv = newSVpvn_utf8(key, klen, is_utf8);
412 keysv = newSVsv(keysv);
415 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
417 /* grab a fake HE/HEK pair from the pool or make a new one */
418 entry = PL_hv_fetch_ent_mh;
420 PL_hv_fetch_ent_mh = HeNEXT(entry);
424 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
425 HeKEY_hek(entry) = (HEK*)k;
427 HeNEXT(entry) = NULL;
428 HeSVKEY_set(entry, keysv);
430 sv_upgrade(sv, SVt_PVLV);
432 /* so we can free entry when freeing sv */
433 LvTARG(sv) = MUTABLE_SV(entry);
435 /* XXX remove at some point? */
436 if (flags & HVhek_FREEKEY)
440 return entry ? (void *) &HeVAL(entry) : NULL;
442 return (void *) entry;
444 #ifdef ENV_IS_CASELESS
445 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
447 for (i = 0; i < klen; ++i)
448 if (isLOWER(key[i])) {
449 /* Would be nice if we had a routine to do the
450 copy and upercase in a single pass through. */
451 const char * const nkey = strupr(savepvn(key,klen));
452 /* Note that this fetch is for nkey (the uppercased
453 key) whereas the store is for key (the original) */
454 void *result = hv_common(hv, NULL, nkey, klen,
455 HVhek_FREEKEY, /* free nkey */
456 0 /* non-LVAL fetch */
457 | HV_DISABLE_UVAR_XKEY
460 0 /* compute hash */);
461 if (!result && (action & HV_FETCH_LVALUE)) {
462 /* This call will free key if necessary.
463 Do it this way to encourage compiler to tail
465 result = hv_common(hv, keysv, key, klen, flags,
467 | HV_DISABLE_UVAR_XKEY
471 if (flags & HVhek_FREEKEY)
479 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
480 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
481 || SvGMAGICAL((const SV *)hv)) {
482 /* I don't understand why hv_exists_ent has svret and sv,
483 whereas hv_exists only had one. */
484 SV * const svret = sv_newmortal();
487 if (keysv || is_utf8) {
489 keysv = newSVpvn_utf8(key, klen, TRUE);
491 keysv = newSVsv(keysv);
493 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
495 mg_copy(MUTABLE_SV(hv), sv, key, klen);
497 if (flags & HVhek_FREEKEY)
499 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
500 /* This cast somewhat evil, but I'm merely using NULL/
501 not NULL to return the boolean exists.
502 And I know hv is not NULL. */
503 return SvTRUE(svret) ? (void *)hv : NULL;
505 #ifdef ENV_IS_CASELESS
506 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
507 /* XXX This code isn't UTF8 clean. */
508 char * const keysave = (char * const)key;
509 /* Will need to free this, so set FREEKEY flag. */
510 key = savepvn(key,klen);
511 key = (const char*)strupr((char*)key);
516 if (flags & HVhek_FREEKEY) {
519 flags |= HVhek_FREEKEY;
523 else if (action & HV_FETCH_ISSTORE) {
526 hv_magic_check (hv, &needs_copy, &needs_store);
528 const bool save_taint = TAINT_get;
529 if (keysv || is_utf8) {
531 keysv = newSVpvn_utf8(key, klen, TRUE);
534 TAINT_set(SvTAINTED(keysv));
535 keysv = sv_2mortal(newSVsv(keysv));
536 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
538 mg_copy(MUTABLE_SV(hv), val, key, klen);
541 TAINT_IF(save_taint);
542 #ifdef NO_TAINT_SUPPORT
543 PERL_UNUSED_VAR(save_taint);
546 if (flags & HVhek_FREEKEY)
550 #ifdef ENV_IS_CASELESS
551 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
552 /* XXX This code isn't UTF8 clean. */
553 const char *keysave = key;
554 /* Will need to free this, so set FREEKEY flag. */
555 key = savepvn(key,klen);
556 key = (const char*)strupr((char*)key);
561 if (flags & HVhek_FREEKEY) {
564 flags |= HVhek_FREEKEY;
572 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
573 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
574 || (SvRMAGICAL((const SV *)hv)
575 && mg_find((const SV *)hv, PERL_MAGIC_env))
580 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
582 HvARRAY(hv) = (HE**)array;
584 #ifdef DYNAMIC_ENV_FETCH
585 else if (action & HV_FETCH_ISEXISTS) {
586 /* for an %ENV exists, if we do an insert it's by a recursive
587 store call, so avoid creating HvARRAY(hv) right now. */
591 /* XXX remove at some point? */
592 if (flags & HVhek_FREEKEY)
599 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
600 char * const keysave = (char *)key;
601 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
605 flags &= ~HVhek_UTF8;
606 if (key != keysave) {
607 if (flags & HVhek_FREEKEY)
609 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
610 /* If the caller calculated a hash, it was on the sequence of
611 octets that are the UTF-8 form. We've now changed the sequence
612 of octets stored to that of the equivalent byte representation,
613 so the hash we need is different. */
618 if (keysv && (SvIsCOW_shared_hash(keysv))) {
620 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
621 hash = SvSHARED_HASH(keysv);
624 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)];
640 /* keysv is actually a HEK in disguise, so we can match just by
641 * comparing the HEK pointers in the HE chain. There is a slight
642 * caveat: on something like "\x80", which has both plain and utf8
643 * representations, perl's hashes do encoding-insensitive lookups,
644 * but preserve the encoding of the stored key. Thus a particular
645 * key could map to two different HEKs in PL_strtab. We only
646 * conclude 'not found' if all the flags are the same; otherwise
647 * we fall back to a full search (this should only happen in rare
650 int keysv_flags = HEK_FLAGS(keysv_hek);
651 HE *orig_entry = entry;
653 for (; entry; entry = HeNEXT(entry)) {
654 HEK *hek = HeKEY_hek(entry);
655 if (hek == keysv_hek)
657 if (HEK_FLAGS(hek) != keysv_flags)
658 break; /* need to do full match */
662 /* failed on shortcut - do full search loop */
666 for (; entry; entry = HeNEXT(entry)) {
667 if (HeHASH(entry) != hash) /* strings can't be equal */
669 if (HeKLEN(entry) != (I32)klen)
671 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
673 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
677 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
678 if (HeKFLAGS(entry) != masked_flags) {
679 /* We match if HVhek_UTF8 bit in our flags and hash key's
680 match. But if entry was set previously with HVhek_WASUTF8
681 and key now doesn't (or vice versa) then we should change
682 the key's flag, as this is assignment. */
683 if (HvSHAREKEYS(hv)) {
684 /* Need to swap the key we have for a key with the flags we
685 need. As keys are shared we can't just write to the
686 flag, so we share the new one, unshare the old one. */
687 HEK * const new_hek = share_hek_flags(key, klen, hash,
689 unshare_hek (HeKEY_hek(entry));
690 HeKEY_hek(entry) = new_hek;
692 else if (hv == PL_strtab) {
693 /* PL_strtab is usually the only hash without HvSHAREKEYS,
694 so putting this test here is cheap */
695 if (flags & HVhek_FREEKEY)
697 Perl_croak(aTHX_ S_strtab_error,
698 action & HV_FETCH_LVALUE ? "fetch" : "store");
701 HeKFLAGS(entry) = masked_flags;
702 if (masked_flags & HVhek_ENABLEHVKFLAGS)
705 if (HeVAL(entry) == &PL_sv_placeholder) {
706 /* yes, can store into placeholder slot */
707 if (action & HV_FETCH_LVALUE) {
709 /* This preserves behaviour with the old hv_fetch
710 implementation which at this point would bail out
711 with a break; (at "if we find a placeholder, we
712 pretend we haven't found anything")
714 That break mean that if a placeholder were found, it
715 caused a call into hv_store, which in turn would
716 check magic, and if there is no magic end up pretty
717 much back at this point (in hv_store's code). */
720 /* LVAL fetch which actually needs a store. */
722 HvPLACEHOLDERS(hv)--;
725 if (val != &PL_sv_placeholder)
726 HvPLACEHOLDERS(hv)--;
729 } else if (action & HV_FETCH_ISSTORE) {
730 SvREFCNT_dec(HeVAL(entry));
733 } else if (HeVAL(entry) == &PL_sv_placeholder) {
734 /* if we find a placeholder, we pretend we haven't found
738 if (flags & HVhek_FREEKEY)
741 return entry ? (void *) &HeVAL(entry) : NULL;
747 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
748 if (!(action & HV_FETCH_ISSTORE)
749 && SvRMAGICAL((const SV *)hv)
750 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
752 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
754 sv = newSVpvn(env,len);
756 return hv_common(hv, keysv, key, klen, flags,
757 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
763 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
764 hv_notallowed(flags, key, klen,
765 "Attempt to access disallowed key '%"SVf"' in"
766 " a restricted hash");
768 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
769 /* Not doing some form of store, so return failure. */
770 if (flags & HVhek_FREEKEY)
774 if (action & HV_FETCH_LVALUE) {
775 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
777 /* At this point the old hv_fetch code would call to hv_store,
778 which in turn might do some tied magic. So we need to make that
779 magic check happen. */
780 /* gonna assign to this, so it better be there */
781 /* If a fetch-as-store fails on the fetch, then the action is to
782 recurse once into "hv_store". If we didn't do this, then that
783 recursive call would call the key conversion routine again.
784 However, as we replace the original key with the converted
785 key, this would result in a double conversion, which would show
786 up as a bug if the conversion routine is not idempotent.
787 Hence the use of HV_DISABLE_UVAR_XKEY. */
788 return hv_common(hv, keysv, key, klen, flags,
789 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
791 /* XXX Surely that could leak if the fetch-was-store fails?
792 Just like the hv_fetch. */
796 /* Welcome to hv_store... */
799 /* Not sure if we can get here. I think the only case of oentry being
800 NULL is for %ENV with dynamic env fetch. But that should disappear
801 with magic in the previous code. */
804 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
806 HvARRAY(hv) = (HE**)array;
809 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
812 /* share_hek_flags will do the free for us. This might be considered
815 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
816 else if (hv == PL_strtab) {
817 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
818 this test here is cheap */
819 if (flags & HVhek_FREEKEY)
821 Perl_croak(aTHX_ S_strtab_error,
822 action & HV_FETCH_LVALUE ? "fetch" : "store");
824 else /* gotta do the real thing */
825 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
828 if (!*oentry && SvOOK(hv)) {
829 /* initial entry, and aux struct present. */
830 struct xpvhv_aux *const aux = HvAUX(hv);
831 if (aux->xhv_fill_lazy)
832 ++aux->xhv_fill_lazy;
835 #ifdef PERL_HASH_RANDOMIZE_KEYS
836 /* This logic semi-randomizes the insert order in a bucket.
837 * Either we insert into the top, or the slot below the top,
838 * making it harder to see if there is a collision. We also
839 * reset the iterator randomizer if there is one.
841 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
843 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
844 if ( PL_hash_rand_bits & 1 ) {
845 HeNEXT(entry) = HeNEXT(*oentry);
846 HeNEXT(*oentry) = entry;
848 HeNEXT(entry) = *oentry;
854 HeNEXT(entry) = *oentry;
857 #ifdef PERL_HASH_RANDOMIZE_KEYS
859 /* Currently this makes various tests warn in annoying ways.
860 * So Silenced for now. - Yves | bogus end of comment =>* /
861 if (HvAUX(hv)->xhv_riter != -1) {
862 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
863 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
868 if (PL_HASH_RAND_BITS_ENABLED) {
869 if (PL_HASH_RAND_BITS_ENABLED == 1)
870 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
871 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
873 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
877 if (val == &PL_sv_placeholder)
878 HvPLACEHOLDERS(hv)++;
879 if (masked_flags & HVhek_ENABLEHVKFLAGS)
882 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
883 if ( DO_HSPLIT(xhv) ) {
884 const STRLEN oldsize = xhv->xhv_max + 1;
885 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
887 if (items /* hash has placeholders */
888 && !SvREADONLY(hv) /* but is not a restricted hash */) {
889 /* If this hash previously was a "restricted hash" and had
890 placeholders, but the "restricted" flag has been turned off,
891 then the placeholders no longer serve any useful purpose.
892 However, they have the downsides of taking up RAM, and adding
893 extra steps when finding used values. It's safe to clear them
894 at this point, even though Storable rebuilds restricted hashes by
895 putting in all the placeholders (first) before turning on the
896 readonly flag, because Storable always pre-splits the hash.
897 If we're lucky, then we may clear sufficient placeholders to
898 avoid needing to split the hash at all. */
899 clear_placeholders(hv, items);
901 hsplit(hv, oldsize, oldsize * 2);
903 hsplit(hv, oldsize, oldsize * 2);
907 return entry ? (void *) &HeVAL(entry) : NULL;
909 return (void *) entry;
913 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
915 const MAGIC *mg = SvMAGIC(hv);
917 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
922 if (isUPPER(mg->mg_type)) {
924 if (mg->mg_type == PERL_MAGIC_tied) {
925 *needs_store = FALSE;
926 return; /* We've set all there is to set. */
929 mg = mg->mg_moremagic;
934 =for apidoc hv_scalar
936 Evaluates the hash in scalar context and returns the result. Handles magic
937 when the hash is tied.
943 Perl_hv_scalar(pTHX_ HV *hv)
947 PERL_ARGS_ASSERT_HV_SCALAR;
949 if (SvRMAGICAL(hv)) {
950 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
952 return magic_scalarpack(hv, mg);
956 if (HvTOTALKEYS((const HV *)hv))
957 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
958 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
966 =for apidoc hv_delete
968 Deletes a key/value pair in the hash. The value's SV is removed from
969 the hash, made mortal, and returned to the caller. The absolute
970 value of C<klen> is the length of the key. If C<klen> is negative the
971 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
972 will normally be zero; if set to G_DISCARD then NULL will be returned.
973 NULL will also be returned if the key is not found.
975 =for apidoc hv_delete_ent
977 Deletes a key/value pair in the hash. The value SV is removed from the hash,
978 made mortal, and returned to the caller. The C<flags> value will normally be
979 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
980 returned if the key is not found. C<hash> can be a valid precomputed hash
981 value, or 0 to ask for it to be computed.
987 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
988 int k_flags, I32 d_flags, U32 hash)
995 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
997 HEK *keysv_hek = NULL;
998 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1003 if (SvRMAGICAL(hv)) {
1006 hv_magic_check (hv, &needs_copy, &needs_store);
1010 entry = (HE *) hv_common(hv, keysv, key, klen,
1011 k_flags & ~HVhek_FREEKEY,
1012 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1014 sv = entry ? HeVAL(entry) : NULL;
1016 if (SvMAGICAL(sv)) {
1020 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1021 /* No longer an element */
1022 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1025 return NULL; /* element cannot be deleted */
1027 #ifdef ENV_IS_CASELESS
1028 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1029 /* XXX This code isn't UTF8 clean. */
1030 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1031 if (k_flags & HVhek_FREEKEY) {
1034 key = strupr(SvPVX(keysv));
1043 xhv = (XPVHV*)SvANY(hv);
1047 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1048 const char * const keysave = key;
1049 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1052 k_flags |= HVhek_UTF8;
1054 k_flags &= ~HVhek_UTF8;
1055 if (key != keysave) {
1056 if (k_flags & HVhek_FREEKEY) {
1057 /* This shouldn't happen if our caller does what we expect,
1058 but strictly the API allows it. */
1061 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1063 HvHASKFLAGS_on(MUTABLE_SV(hv));
1066 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1067 if (HvSHAREKEYS(hv))
1068 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1069 hash = SvSHARED_HASH(keysv);
1072 PERL_HASH(hash, key, klen);
1074 masked_flags = (k_flags & HVhek_MASK);
1076 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1083 /* keysv is actually a HEK in disguise, so we can match just by
1084 * comparing the HEK pointers in the HE chain. There is a slight
1085 * caveat: on something like "\x80", which has both plain and utf8
1086 * representations, perl's hashes do encoding-insensitive lookups,
1087 * but preserve the encoding of the stored key. Thus a particular
1088 * key could map to two different HEKs in PL_strtab. We only
1089 * conclude 'not found' if all the flags are the same; otherwise
1090 * we fall back to a full search (this should only happen in rare
1093 int keysv_flags = HEK_FLAGS(keysv_hek);
1095 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1096 HEK *hek = HeKEY_hek(entry);
1097 if (hek == keysv_hek)
1099 if (HEK_FLAGS(hek) != keysv_flags)
1100 break; /* need to do full match */
1104 /* failed on shortcut - do full search loop */
1105 oentry = first_entry;
1109 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1110 if (HeHASH(entry) != hash) /* strings can't be equal */
1112 if (HeKLEN(entry) != (I32)klen)
1114 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1116 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1120 if (hv == PL_strtab) {
1121 if (k_flags & HVhek_FREEKEY)
1123 Perl_croak(aTHX_ S_strtab_error, "delete");
1126 /* if placeholder is here, it's already been deleted.... */
1127 if (HeVAL(entry) == &PL_sv_placeholder) {
1128 if (k_flags & HVhek_FREEKEY)
1132 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1133 hv_notallowed(k_flags, key, klen,
1134 "Attempt to delete readonly key '%"SVf"' from"
1135 " a restricted hash");
1137 if (k_flags & HVhek_FREEKEY)
1140 /* If this is a stash and the key ends with ::, then someone is
1141 * deleting a package.
1143 if (HeVAL(entry) && HvENAME_get(hv)) {
1144 gv = (GV *)HeVAL(entry);
1145 if (keysv) key = SvPV(keysv, klen);
1147 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1149 (klen == 1 && key[0] == ':')
1151 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1152 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1153 && HvENAME_get(stash)) {
1154 /* A previous version of this code checked that the
1155 * GV was still in the symbol table by fetching the
1156 * GV with its name. That is not necessary (and
1157 * sometimes incorrect), as HvENAME cannot be set
1158 * on hv if it is not in the symtab. */
1160 /* Hang on to it for a bit. */
1161 SvREFCNT_inc_simple_void_NN(
1162 sv_2mortal((SV *)gv)
1165 else if (klen == 3 && strnEQ(key, "ISA", 3))
1169 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1170 HeVAL(entry) = &PL_sv_placeholder;
1172 /* deletion of method from stash */
1173 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1175 mro_method_changed_in(hv);
1179 * If a restricted hash, rather than really deleting the entry, put
1180 * a placeholder there. This marks the key as being "approved", so
1181 * we can still access via not-really-existing key without raising
1185 /* We'll be saving this slot, so the number of allocated keys
1186 * doesn't go down, but the number placeholders goes up */
1187 HvPLACEHOLDERS(hv)++;
1189 *oentry = HeNEXT(entry);
1190 if(!*first_entry && SvOOK(hv)) {
1191 /* removed last entry, and aux struct present. */
1192 struct xpvhv_aux *const aux = HvAUX(hv);
1193 if (aux->xhv_fill_lazy)
1194 --aux->xhv_fill_lazy;
1196 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1199 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1200 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1201 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1202 hv_free_ent(hv, entry);
1204 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1205 if (xhv->xhv_keys == 0)
1206 HvHASKFLAGS_off(hv);
1209 if (d_flags & G_DISCARD) {
1214 if (mro_changes == 1) mro_isa_changed_in(hv);
1215 else if (mro_changes == 2)
1216 mro_package_moved(NULL, stash, gv, 1);
1222 if (SvREADONLY(hv)) {
1223 hv_notallowed(k_flags, key, klen,
1224 "Attempt to delete disallowed key '%"SVf"' from"
1225 " a restricted hash");
1228 if (k_flags & HVhek_FREEKEY)
1235 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1238 char *a = (char*) HvARRAY(hv);
1242 /* already have an HvAUX(hv) so we have to move it */
1244 /* no HvAUX() but array we are going to allocate is large enough
1245 * there is no point in saving the space for the iterator, and
1246 * speeds up later traversals. */
1247 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1250 PERL_ARGS_ASSERT_HSPLIT;
1253 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1254 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1260 #ifdef PERL_HASH_RANDOMIZE_KEYS
1261 /* the idea of this is that we create a "random" value by hashing the address of
1262 * the array, we then use the low bit to decide if we insert at the top, or insert
1263 * second from top. After each such insert we rotate the hashed value. So we can
1264 * use the same hashed value over and over, and in normal build environments use
1265 * very few ops to do so. ROTL32() should produce a single machine operation. */
1266 if (PL_HASH_RAND_BITS_ENABLED) {
1267 if (PL_HASH_RAND_BITS_ENABLED == 1)
1268 PL_hash_rand_bits += ptr_hash((PTRV)a);
1269 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1272 HvARRAY(hv) = (HE**) a;
1273 HvMAX(hv) = newsize - 1;
1274 /* before we zero the newly added memory, we
1275 * need to deal with the aux struct that may be there
1276 * or have been allocated by us*/
1278 struct xpvhv_aux *const dest
1279 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1281 /* alread have an aux, copy the old one in place. */
1282 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1283 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1284 #ifdef PERL_HASH_RANDOMIZE_KEYS
1285 dest->xhv_rand = (U32)PL_hash_rand_bits;
1287 /* For now, just reset the lazy fill counter.
1288 It would be possible to update the counter in the code below
1290 dest->xhv_fill_lazy = 0;
1292 /* no existing aux structure, but we allocated space for one
1293 * so initialize it properly. This unrolls hv_auxinit() a bit,
1294 * since we have to do the realloc anyway. */
1295 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1296 #ifdef PERL_HASH_RANDOMIZE_KEYS
1297 dest->xhv_rand = (U32)PL_hash_rand_bits;
1299 /* this is the "non realloc" part of the hv_auxinit() */
1300 (void)hv_auxinit_internal(dest);
1301 /* Turn on the OOK flag */
1305 /* now we can safely clear the second half */
1306 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1308 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1314 HE **oentry = aep + i;
1317 if (!entry) /* non-existent */
1320 U32 j = (HeHASH(entry) & newsize);
1322 *oentry = HeNEXT(entry);
1323 #ifdef PERL_HASH_RANDOMIZE_KEYS
1324 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1325 * insert to top, otherwise rotate the bucket rand 1 bit,
1326 * and use the new low bit to decide if we insert at top,
1327 * or next from top. IOW, we only rotate on a collision.*/
1328 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1329 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1330 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1331 if (PL_hash_rand_bits & 1) {
1332 HeNEXT(entry)= HeNEXT(aep[j]);
1333 HeNEXT(aep[j])= entry;
1335 /* Note, this is structured in such a way as the optimizer
1336 * should eliminate the duplicated code here and below without
1337 * us needing to explicitly use a goto. */
1338 HeNEXT(entry) = aep[j];
1344 /* see comment above about duplicated code */
1345 HeNEXT(entry) = aep[j];
1350 oentry = &HeNEXT(entry);
1354 } while (i++ < oldsize);
1358 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1360 XPVHV* xhv = (XPVHV*)SvANY(hv);
1361 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1365 PERL_ARGS_ASSERT_HV_KSPLIT;
1367 newsize = (I32) newmax; /* possible truncation here */
1368 if (newsize != newmax || newmax <= oldsize)
1370 while ((newsize & (1 + ~newsize)) != newsize) {
1371 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1373 if (newsize < newmax)
1375 if (newsize < newmax)
1376 return; /* overflow detection */
1378 a = (char *) HvARRAY(hv);
1380 hsplit(hv, oldsize, newsize);
1382 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1383 xhv->xhv_max = --newsize;
1384 HvARRAY(hv) = (HE **) a;
1388 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1389 * as tied hashes could play silly buggers and mess us around. We will
1390 * do the right thing during hv_store() afterwards, but still - Yves */
1391 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1392 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1393 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1394 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1396 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1397 hv_max = hv_max / 2; \
1399 HvMAX(hv) = hv_max; \
1404 Perl_newHVhv(pTHX_ HV *ohv)
1407 HV * const hv = newHV();
1410 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1412 hv_max = HvMAX(ohv);
1414 if (!SvMAGICAL((const SV *)ohv)) {
1415 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1417 const bool shared = !!HvSHAREKEYS(ohv);
1418 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1420 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1423 /* In each bucket... */
1424 for (i = 0; i <= hv_max; i++) {
1426 HE *oent = oents[i];
1433 /* Copy the linked list of entries. */
1434 for (; oent; oent = HeNEXT(oent)) {
1435 const U32 hash = HeHASH(oent);
1436 const char * const key = HeKEY(oent);
1437 const STRLEN len = HeKLEN(oent);
1438 const int flags = HeKFLAGS(oent);
1439 HE * const ent = new_HE();
1440 SV *const val = HeVAL(oent);
1442 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1444 = shared ? share_hek_flags(key, len, hash, flags)
1445 : save_hek_flags(key, len, hash, flags);
1456 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1460 /* Iterate over ohv, copying keys and values one at a time. */
1462 const I32 riter = HvRITER_get(ohv);
1463 HE * const eiter = HvEITER_get(ohv);
1464 STRLEN hv_keys = HvTOTALKEYS(ohv);
1466 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1469 while ((entry = hv_iternext_flags(ohv, 0))) {
1470 SV *val = hv_iterval(ohv,entry);
1471 SV * const keysv = HeSVKEY(entry);
1472 val = SvIMMORTAL(val) ? val : newSVsv(val);
1474 (void)hv_store_ent(hv, keysv, val, 0);
1476 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1477 HeHASH(entry), HeKFLAGS(entry));
1479 HvRITER_set(ohv, riter);
1480 HvEITER_set(ohv, eiter);
1487 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1489 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1490 a pointer to a hash (which may have C<%^H> magic, but should be generally
1491 non-magical), or C<NULL> (interpreted as an empty hash). The content
1492 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1493 added to it. A pointer to the new hash is returned.
1499 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1501 HV * const hv = newHV();
1504 STRLEN hv_max = HvMAX(ohv);
1505 STRLEN hv_keys = HvTOTALKEYS(ohv);
1507 const I32 riter = HvRITER_get(ohv);
1508 HE * const eiter = HvEITER_get(ohv);
1513 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1516 while ((entry = hv_iternext_flags(ohv, 0))) {
1517 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1518 SV *heksv = HeSVKEY(entry);
1519 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1520 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1521 (char *)heksv, HEf_SVKEY);
1522 if (heksv == HeSVKEY(entry))
1523 (void)hv_store_ent(hv, heksv, sv, 0);
1525 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1526 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1527 SvREFCNT_dec_NN(heksv);
1530 HvRITER_set(ohv, riter);
1531 HvEITER_set(ohv, eiter);
1533 SvREFCNT_inc_simple_void_NN(hv);
1536 hv_magic(hv, NULL, PERL_MAGIC_hints);
1539 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1541 /* like hv_free_ent, but returns the SV rather than freeing it */
1543 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1547 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1550 if (HeKLEN(entry) == HEf_SVKEY) {
1551 SvREFCNT_dec(HeKEY_sv(entry));
1552 Safefree(HeKEY_hek(entry));
1554 else if (HvSHAREKEYS(hv))
1555 unshare_hek(HeKEY_hek(entry));
1557 Safefree(HeKEY_hek(entry));
1564 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1568 PERL_ARGS_ASSERT_HV_FREE_ENT;
1572 val = hv_free_ent_ret(hv, entry);
1578 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1580 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1584 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1585 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1586 if (HeKLEN(entry) == HEf_SVKEY) {
1587 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1589 hv_free_ent(hv, entry);
1593 =for apidoc hv_clear
1595 Frees the all the elements of a hash, leaving it empty.
1596 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1598 If any destructors are triggered as a result, the hv itself may
1605 Perl_hv_clear(pTHX_ HV *hv)
1612 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1614 xhv = (XPVHV*)SvANY(hv);
1617 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1618 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1619 /* restricted hash: convert all keys to placeholders */
1621 for (i = 0; i <= xhv->xhv_max; i++) {
1622 HE *entry = (HvARRAY(hv))[i];
1623 for (; entry; entry = HeNEXT(entry)) {
1624 /* not already placeholder */
1625 if (HeVAL(entry) != &PL_sv_placeholder) {
1627 if (SvREADONLY(HeVAL(entry))) {
1628 SV* const keysv = hv_iterkeysv(entry);
1629 Perl_croak_nocontext(
1630 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1633 SvREFCNT_dec_NN(HeVAL(entry));
1635 HeVAL(entry) = &PL_sv_placeholder;
1636 HvPLACEHOLDERS(hv)++;
1643 HvPLACEHOLDERS_set(hv, 0);
1646 mg_clear(MUTABLE_SV(hv));
1648 HvHASKFLAGS_off(hv);
1652 mro_isa_changed_in(hv);
1653 HvEITER_set(hv, NULL);
1659 =for apidoc hv_clear_placeholders
1661 Clears any placeholders from a hash. If a restricted hash has any of its keys
1662 marked as readonly and the key is subsequently deleted, the key is not actually
1663 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1664 it so it will be ignored by future operations such as iterating over the hash,
1665 but will still allow the hash to have a value reassigned to the key at some
1666 future point. This function clears any such placeholder keys from the hash.
1667 See Hash::Util::lock_keys() for an example of its use.
1673 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1675 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1677 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1680 clear_placeholders(hv, items);
1684 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1689 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1696 /* Loop down the linked list heads */
1697 HE **oentry = &(HvARRAY(hv))[i];
1700 while ((entry = *oentry)) {
1701 if (HeVAL(entry) == &PL_sv_placeholder) {
1702 *oentry = HeNEXT(entry);
1703 if (entry == HvEITER_get(hv))
1706 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1707 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1708 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1709 hv_free_ent(hv, entry);
1714 I32 placeholders = HvPLACEHOLDERS_get(hv);
1715 HvTOTALKEYS(hv) -= (IV)placeholders;
1716 /* HvUSEDKEYS expanded */
1717 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1718 HvHASKFLAGS_off(hv);
1719 HvPLACEHOLDERS_set(hv, 0);
1723 oentry = &HeNEXT(entry);
1727 /* You can't get here, hence assertion should always fail. */
1728 assert (items == 0);
1729 NOT_REACHED; /* NOTREACHED */
1733 S_hfreeentries(pTHX_ HV *hv)
1736 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1739 PERL_ARGS_ASSERT_HFREEENTRIES;
1741 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1747 /* hfree_next_entry()
1748 * For use only by S_hfreeentries() and sv_clear().
1749 * Delete the next available HE from hv and return the associated SV.
1750 * Returns null on empty hash. Nevertheless null is not a reliable
1751 * indicator that the hash is empty, as the deleted entry may have a
1753 * indexp is a pointer to the current index into HvARRAY. The index should
1754 * initially be set to 0. hfree_next_entry() may update it. */
1757 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1759 struct xpvhv_aux *iter;
1763 STRLEN orig_index = *indexp;
1766 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1768 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1769 if ((entry = iter->xhv_eiter)) {
1770 /* the iterator may get resurrected after each
1771 * destructor call, so check each time */
1772 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1774 hv_free_ent(hv, entry);
1775 /* warning: at this point HvARRAY may have been
1776 * re-allocated, HvMAX changed etc */
1778 iter = HvAUX(hv); /* may have been realloced */
1779 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1780 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1781 #ifdef PERL_HASH_RANDOMIZE_KEYS
1782 iter->xhv_last_rand = iter->xhv_rand;
1785 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1786 will actually call HvFILL() on a hash under destruction, so it
1787 seems pointless attempting to track the number of keys remaining.
1788 But if they do, we want to reset it again. */
1789 if (iter->xhv_fill_lazy)
1790 iter->xhv_fill_lazy = 0;
1793 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1796 array = HvARRAY(hv);
1798 while ( ! ((entry = array[*indexp])) ) {
1799 if ((*indexp)++ >= HvMAX(hv))
1801 assert(*indexp != orig_index);
1803 array[*indexp] = HeNEXT(entry);
1804 ((XPVHV*) SvANY(hv))->xhv_keys--;
1806 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1807 && HeVAL(entry) && isGV(HeVAL(entry))
1808 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1811 const char * const key = HePV(entry,klen);
1812 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1813 || (klen == 1 && key[0] == ':')) {
1815 NULL, GvHV(HeVAL(entry)),
1816 (GV *)HeVAL(entry), 0
1820 return hv_free_ent_ret(hv, entry);
1825 =for apidoc hv_undef
1827 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1829 As well as freeing all the elements of the hash (like hv_clear()), this
1830 also frees any auxiliary data and storage associated with the hash.
1832 If any destructors are triggered as a result, the hv itself may
1835 See also L</hv_clear>.
1841 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1848 save = !!SvREFCNT(hv);
1849 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1850 xhv = (XPVHV*)SvANY(hv);
1852 /* The name must be deleted before the call to hfreeeeentries so that
1853 CVs are anonymised properly. But the effective name must be pre-
1854 served until after that call (and only deleted afterwards if the
1855 call originated from sv_clear). For stashes with one name that is
1856 both the canonical name and the effective name, hv_name_set has to
1857 allocate an array for storing the effective name. We can skip that
1858 during global destruction, as it does not matter where the CVs point
1859 if they will be freed anyway. */
1860 /* note that the code following prior to hfreeentries is duplicated
1861 * in sv_clear(), and changes here should be done there too */
1862 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1863 if (PL_stashcache) {
1864 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1865 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1866 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1868 hv_name_set(hv, NULL, 0, 0);
1872 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1876 struct mro_meta *meta;
1879 if (HvENAME_get(hv)) {
1880 if (PL_phase != PERL_PHASE_DESTRUCT)
1881 mro_isa_changed_in(hv);
1882 if (PL_stashcache) {
1883 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1884 HEKf"'\n", HEKfARG(HvENAME_HEK(hv))));
1885 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1889 /* If this call originated from sv_clear, then we must check for
1890 * effective names that need freeing, as well as the usual name. */
1892 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
1893 if (name && PL_stashcache) {
1894 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1895 HEKf"'\n", HEKfARG(HvNAME_HEK(hv))));
1896 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1898 hv_name_set(hv, NULL, 0, flags);
1900 if((meta = HvAUX(hv)->xhv_mro_meta)) {
1901 if (meta->mro_linear_all) {
1902 SvREFCNT_dec_NN(meta->mro_linear_all);
1903 /* mro_linear_current is just acting as a shortcut pointer,
1907 /* Only the current MRO is stored, so this owns the data.
1909 SvREFCNT_dec(meta->mro_linear_current);
1910 SvREFCNT_dec(meta->mro_nextmethod);
1911 SvREFCNT_dec(meta->isa);
1912 SvREFCNT_dec(meta->super);
1914 HvAUX(hv)->xhv_mro_meta = NULL;
1916 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
1917 SvFLAGS(hv) &= ~SVf_OOK;
1920 Safefree(HvARRAY(hv));
1921 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1924 /* if we're freeing the HV, the SvMAGIC field has been reused for
1925 * other purposes, and so there can't be any placeholder magic */
1927 HvPLACEHOLDERS_set(hv, 0);
1930 mg_clear(MUTABLE_SV(hv));
1937 Returns the number of hash buckets that
1938 happen to be in use. This function is
1939 wrapped by the macro C<HvFILL>.
1941 Previously this value was always stored in the HV structure, which created an
1942 overhead on every hash (and pretty much every object) for something that was
1943 rarely used. Now we calculate it on demand the first
1944 time that it is needed, and cache it if that calculation
1945 is going to be costly to repeat. The cached
1946 value is updated by insertions and deletions, but (currently) discarded if
1953 Perl_hv_fill(pTHX_ HV *const hv)
1956 HE **ents = HvARRAY(hv);
1957 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1959 PERL_ARGS_ASSERT_HV_FILL;
1961 /* No keys implies no buckets used.
1962 One key can only possibly mean one bucket used. */
1963 if (HvTOTALKEYS(hv) < 2)
1964 return HvTOTALKEYS(hv);
1967 if (aux && aux->xhv_fill_lazy)
1968 return aux->xhv_fill_lazy;
1972 HE *const *const last = ents + HvMAX(hv);
1973 count = last + 1 - ents;
1978 } while (++ents <= last);
1982 if (aux->xhv_fill_lazy)
1983 assert(aux->xhv_fill_lazy == count);
1985 aux->xhv_fill_lazy = count;
1986 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1987 aux = hv_auxinit(hv);
1988 aux->xhv_fill_lazy = count;
1993 /* hash a pointer to a U32 - Used in the hash traversal randomization
1994 * and bucket order randomization code
1996 * this code was derived from Sereal, which was derived from autobox.
1999 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2002 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2003 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2005 u = (~u) + (u << 18);
2013 * This is one of Bob Jenkins' hash functions for 32-bit integers
2014 * from: http://burtleburtle.net/bob/hash/integer.html
2016 u = (u + 0x7ed55d16) + (u << 12);
2017 u = (u ^ 0xc761c23c) ^ (u >> 19);
2018 u = (u + 0x165667b1) + (u << 5);
2019 u = (u + 0xd3a2646c) ^ (u << 9);
2020 u = (u + 0xfd7046c5) + (u << 3);
2021 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2026 static struct xpvhv_aux*
2027 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
2028 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
2029 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2030 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2031 #ifdef PERL_HASH_RANDOMIZE_KEYS
2032 iter->xhv_last_rand = iter->xhv_rand;
2034 iter->xhv_fill_lazy = 0;
2035 iter->xhv_name_u.xhvnameu_name = 0;
2036 iter->xhv_name_count = 0;
2037 iter->xhv_backreferences = 0;
2038 iter->xhv_mro_meta = NULL;
2039 iter->xhv_aux_flags = 0;
2044 static struct xpvhv_aux*
2045 S_hv_auxinit(pTHX_ HV *hv) {
2046 struct xpvhv_aux *iter;
2049 PERL_ARGS_ASSERT_HV_AUXINIT;
2053 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2054 + sizeof(struct xpvhv_aux), char);
2056 array = (char *) HvARRAY(hv);
2057 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2058 + sizeof(struct xpvhv_aux), char);
2060 HvARRAY(hv) = (HE**)array;
2063 #ifdef PERL_HASH_RANDOMIZE_KEYS
2064 if (PL_HASH_RAND_BITS_ENABLED) {
2065 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2066 if (PL_HASH_RAND_BITS_ENABLED == 1)
2067 PL_hash_rand_bits += ptr_hash((PTRV)array);
2068 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2070 iter->xhv_rand = (U32)PL_hash_rand_bits;
2076 return hv_auxinit_internal(iter);
2080 =for apidoc hv_iterinit
2082 Prepares a starting point to traverse a hash table. Returns the number of
2083 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
2084 currently only meaningful for hashes without tie magic.
2086 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2087 hash buckets that happen to be in use. If you still need that esoteric
2088 value, you can get it through the macro C<HvFILL(hv)>.
2095 Perl_hv_iterinit(pTHX_ HV *hv)
2097 PERL_ARGS_ASSERT_HV_ITERINIT;
2100 struct xpvhv_aux * iter = HvAUX(hv);
2101 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2102 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2104 hv_free_ent(hv, entry);
2106 iter = HvAUX(hv); /* may have been reallocated */
2107 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2108 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2109 #ifdef PERL_HASH_RANDOMIZE_KEYS
2110 iter->xhv_last_rand = iter->xhv_rand;
2116 /* used to be xhv->xhv_fill before 5.004_65 */
2117 return HvTOTALKEYS(hv);
2121 Perl_hv_riter_p(pTHX_ HV *hv) {
2122 struct xpvhv_aux *iter;
2124 PERL_ARGS_ASSERT_HV_RITER_P;
2126 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2127 return &(iter->xhv_riter);
2131 Perl_hv_eiter_p(pTHX_ HV *hv) {
2132 struct xpvhv_aux *iter;
2134 PERL_ARGS_ASSERT_HV_EITER_P;
2136 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2137 return &(iter->xhv_eiter);
2141 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2142 struct xpvhv_aux *iter;
2144 PERL_ARGS_ASSERT_HV_RITER_SET;
2152 iter = hv_auxinit(hv);
2154 iter->xhv_riter = riter;
2158 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2159 struct xpvhv_aux *iter;
2161 PERL_ARGS_ASSERT_HV_RAND_SET;
2163 #ifdef PERL_HASH_RANDOMIZE_KEYS
2167 iter = hv_auxinit(hv);
2169 iter->xhv_rand = new_xhv_rand;
2171 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2176 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2177 struct xpvhv_aux *iter;
2179 PERL_ARGS_ASSERT_HV_EITER_SET;
2184 /* 0 is the default so don't go malloc()ing a new structure just to
2189 iter = hv_auxinit(hv);
2191 iter->xhv_eiter = eiter;
2195 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2198 struct xpvhv_aux *iter;
2202 PERL_ARGS_ASSERT_HV_NAME_SET;
2205 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2209 if (iter->xhv_name_u.xhvnameu_name) {
2210 if(iter->xhv_name_count) {
2211 if(flags & HV_NAME_SETALL) {
2212 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2213 HEK **hekp = name + (
2214 iter->xhv_name_count < 0
2215 ? -iter->xhv_name_count
2216 : iter->xhv_name_count
2218 while(hekp-- > name+1)
2219 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2220 /* The first elem may be null. */
2221 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2223 iter = HvAUX(hv); /* may been realloced */
2224 spot = &iter->xhv_name_u.xhvnameu_name;
2225 iter->xhv_name_count = 0;
2228 if(iter->xhv_name_count > 0) {
2229 /* shift some things over */
2231 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2233 spot = iter->xhv_name_u.xhvnameu_names;
2234 spot[iter->xhv_name_count] = spot[1];
2236 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2238 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2239 unshare_hek_or_pvn(*spot, 0, 0, 0);
2243 else if (flags & HV_NAME_SETALL) {
2244 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2245 iter = HvAUX(hv); /* may been realloced */
2246 spot = &iter->xhv_name_u.xhvnameu_name;
2249 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2250 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2251 iter->xhv_name_count = -2;
2252 spot = iter->xhv_name_u.xhvnameu_names;
2253 spot[1] = existing_name;
2256 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2261 iter = hv_auxinit(hv);
2262 spot = &iter->xhv_name_u.xhvnameu_name;
2264 PERL_HASH(hash, name, len);
2265 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2269 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2274 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2275 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2276 if (flags & SVf_UTF8)
2277 return (bytes_cmp_utf8(
2278 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2279 (const U8*)pv, pvlen) == 0);
2281 return (bytes_cmp_utf8(
2282 (const U8*)pv, pvlen,
2283 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2286 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2287 || memEQ(HEK_KEY(hek), pv, pvlen));
2291 =for apidoc hv_ename_add
2293 Adds a name to a stash's internal list of effective names. See
2296 This is called when a stash is assigned to a new location in the symbol
2303 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2306 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2309 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2312 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2314 PERL_HASH(hash, name, len);
2316 if (aux->xhv_name_count) {
2317 I32 count = aux->xhv_name_count;
2318 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2319 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2320 while (hekp-- > xhv_name)
2324 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2325 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2326 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2328 if (hekp == xhv_name && count < 0)
2329 aux->xhv_name_count = -count;
2333 if (count < 0) aux->xhv_name_count--, count = -count;
2334 else aux->xhv_name_count++;
2335 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2336 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2339 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2342 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2343 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2344 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2347 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2348 aux->xhv_name_count = existing_name ? 2 : -2;
2349 *aux->xhv_name_u.xhvnameu_names = existing_name;
2350 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2355 =for apidoc hv_ename_delete
2357 Removes a name from a stash's internal list of effective names. If this is
2358 the name returned by C<HvENAME>, then another name in the list will take
2359 its place (C<HvENAME> will use it).
2361 This is called when a stash is deleted from the symbol table.
2367 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2369 struct xpvhv_aux *aux;
2371 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2374 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2376 if (!SvOOK(hv)) return;
2379 if (!aux->xhv_name_u.xhvnameu_name) return;
2381 if (aux->xhv_name_count) {
2382 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2383 I32 const count = aux->xhv_name_count;
2384 HEK **victim = namep + (count < 0 ? -count : count);
2385 while (victim-- > namep + 1)
2387 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2388 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2389 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2391 unshare_hek_or_pvn(*victim, 0, 0, 0);
2392 aux = HvAUX(hv); /* may been realloced */
2393 if (count < 0) ++aux->xhv_name_count;
2394 else --aux->xhv_name_count;
2396 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2398 ) { /* if there are none left */
2400 aux->xhv_name_u.xhvnameu_names = NULL;
2401 aux->xhv_name_count = 0;
2404 /* Move the last one back to fill the empty slot. It
2405 does not matter what order they are in. */
2406 *victim = *(namep + (count < 0 ? -count : count) - 1);
2411 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2412 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2413 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2415 aux->xhv_name_count = -count;
2419 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2420 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2421 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2422 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2424 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2425 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2426 *aux->xhv_name_u.xhvnameu_names = namehek;
2427 aux->xhv_name_count = -1;
2432 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2433 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2434 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2436 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2437 return &(iter->xhv_backreferences);
2442 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2445 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2450 av = HvAUX(hv)->xhv_backreferences;
2453 HvAUX(hv)->xhv_backreferences = 0;
2454 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2455 if (SvTYPE(av) == SVt_PVAV)
2456 SvREFCNT_dec_NN(av);
2461 hv_iternext is implemented as a macro in hv.h
2463 =for apidoc hv_iternext
2465 Returns entries from a hash iterator. See C<hv_iterinit>.
2467 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2468 iterator currently points to, without losing your place or invalidating your
2469 iterator. Note that in this case the current entry is deleted from the hash
2470 with your iterator holding the last reference to it. Your iterator is flagged
2471 to free the entry on the next call to C<hv_iternext>, so you must not discard
2472 your iterator immediately else the entry will leak - call C<hv_iternext> to
2473 trigger the resource deallocation.
2475 =for apidoc hv_iternext_flags
2477 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2478 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2479 set the placeholders keys (for restricted hashes) will be returned in addition
2480 to normal keys. By default placeholders are automatically skipped over.
2481 Currently a placeholder is implemented with a value that is
2482 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2483 restricted hashes may change, and the implementation currently is
2484 insufficiently abstracted for any change to be tidy.
2490 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2497 struct xpvhv_aux *iter;
2499 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2501 xhv = (XPVHV*)SvANY(hv);
2504 /* Too many things (well, pp_each at least) merrily assume that you can
2505 call hv_iternext without calling hv_iterinit, so we'll have to deal
2511 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2512 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2513 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2514 SV * const key = sv_newmortal();
2516 sv_setsv(key, HeSVKEY_force(entry));
2517 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2518 HeSVKEY_set(entry, NULL);
2524 /* one HE per MAGICAL hash */
2525 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2526 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2528 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2530 HeKEY_hek(entry) = hek;
2531 HeKLEN(entry) = HEf_SVKEY;
2533 magic_nextpack(MUTABLE_SV(hv),mg,key);
2535 /* force key to stay around until next time */
2536 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2537 return entry; /* beware, hent_val is not set */
2539 SvREFCNT_dec(HeVAL(entry));
2540 Safefree(HeKEY_hek(entry));
2542 iter = HvAUX(hv); /* may been realloced */
2543 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2548 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2549 if (!entry && SvRMAGICAL((const SV *)hv)
2550 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2553 /* The prime_env_iter() on VMS just loaded up new hash values
2554 * so the iteration count needs to be reset back to the beginning
2558 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2563 /* hv_iterinit now ensures this. */
2564 assert (HvARRAY(hv));
2566 /* At start of hash, entry is NULL. */
2569 entry = HeNEXT(entry);
2570 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2572 * Skip past any placeholders -- don't want to include them in
2575 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2576 entry = HeNEXT(entry);
2581 #ifdef PERL_HASH_RANDOMIZE_KEYS
2582 if (iter->xhv_last_rand != iter->xhv_rand) {
2583 if (iter->xhv_riter != -1) {
2584 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2585 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2589 iter = HvAUX(hv); /* may been realloced */
2590 iter->xhv_last_rand = iter->xhv_rand;
2594 /* Skip the entire loop if the hash is empty. */
2595 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2596 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2598 /* OK. Come to the end of the current list. Grab the next one. */
2600 iter->xhv_riter++; /* HvRITER(hv)++ */
2601 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2602 /* There is no next one. End of the hash. */
2603 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2604 #ifdef PERL_HASH_RANDOMIZE_KEYS
2605 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2609 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2611 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2612 /* If we have an entry, but it's a placeholder, don't count it.
2614 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2615 entry = HeNEXT(entry);
2617 /* Will loop again if this linked list starts NULL
2618 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2619 or if we run through it and find only placeholders. */
2623 iter->xhv_riter = -1;
2624 #ifdef PERL_HASH_RANDOMIZE_KEYS
2625 iter->xhv_last_rand = iter->xhv_rand;
2629 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2631 hv_free_ent(hv, oldentry);
2634 iter = HvAUX(hv); /* may been realloced */
2635 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2640 =for apidoc hv_iterkey
2642 Returns the key from the current position of the hash iterator. See
2649 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2651 PERL_ARGS_ASSERT_HV_ITERKEY;
2653 if (HeKLEN(entry) == HEf_SVKEY) {
2655 char * const p = SvPV(HeKEY_sv(entry), len);
2660 *retlen = HeKLEN(entry);
2661 return HeKEY(entry);
2665 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2667 =for apidoc hv_iterkeysv
2669 Returns the key as an C<SV*> from the current position of the hash
2670 iterator. The return value will always be a mortal copy of the key. Also
2677 Perl_hv_iterkeysv(pTHX_ HE *entry)
2679 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2681 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2685 =for apidoc hv_iterval
2687 Returns the value from the current position of the hash iterator. See
2694 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2696 PERL_ARGS_ASSERT_HV_ITERVAL;
2698 if (SvRMAGICAL(hv)) {
2699 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2700 SV* const sv = sv_newmortal();
2701 if (HeKLEN(entry) == HEf_SVKEY)
2702 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2704 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2708 return HeVAL(entry);
2712 =for apidoc hv_iternextsv
2714 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2721 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2723 HE * const he = hv_iternext_flags(hv, 0);
2725 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2729 *key = hv_iterkey(he, retlen);
2730 return hv_iterval(hv, he);
2737 =for apidoc hv_magic
2739 Adds magic to a hash. See C<sv_magic>.
2744 /* possibly free a shared string if no one has access to it
2745 * len and hash must both be valid for str.
2748 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2750 unshare_hek_or_pvn (NULL, str, len, hash);
2755 Perl_unshare_hek(pTHX_ HEK *hek)
2758 unshare_hek_or_pvn(hek, NULL, 0, 0);
2761 /* possibly free a shared string if no one has access to it
2762 hek if non-NULL takes priority over the other 3, else str, len and hash
2763 are used. If so, len and hash must both be valid for str.
2766 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2771 bool is_utf8 = FALSE;
2773 const char * const save = str;
2774 struct shared_he *he = NULL;
2777 /* Find the shared he which is just before us in memory. */
2778 he = (struct shared_he *)(((char *)hek)
2779 - STRUCT_OFFSET(struct shared_he,
2782 /* Assert that the caller passed us a genuine (or at least consistent)
2784 assert (he->shared_he_he.hent_hek == hek);
2786 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2787 --he->shared_he_he.he_valu.hent_refcount;
2791 hash = HEK_HASH(hek);
2792 } else if (len < 0) {
2793 STRLEN tmplen = -len;
2795 /* See the note in hv_fetch(). --jhi */
2796 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2799 k_flags = HVhek_UTF8;
2801 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2804 /* what follows was the moral equivalent of:
2805 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2807 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2809 xhv = (XPVHV*)SvANY(PL_strtab);
2810 /* assert(xhv_array != 0) */
2811 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2813 const HE *const he_he = &(he->shared_he_he);
2814 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2819 const int flags_masked = k_flags & HVhek_MASK;
2820 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2821 if (HeHASH(entry) != hash) /* strings can't be equal */
2823 if (HeKLEN(entry) != len)
2825 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2827 if (HeKFLAGS(entry) != flags_masked)
2834 if (--entry->he_valu.hent_refcount == 0) {
2835 *oentry = HeNEXT(entry);
2837 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2842 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2843 "Attempt to free nonexistent shared string '%s'%s"
2845 hek ? HEK_KEY(hek) : str,
2846 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2847 if (k_flags & HVhek_FREEKEY)
2851 /* get a (constant) string ptr from the global string table
2852 * string will get added if it is not already there.
2853 * len and hash must both be valid for str.
2856 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2858 bool is_utf8 = FALSE;
2860 const char * const save = str;
2862 PERL_ARGS_ASSERT_SHARE_HEK;
2865 STRLEN tmplen = -len;
2867 /* See the note in hv_fetch(). --jhi */
2868 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2870 /* If we were able to downgrade here, then than means that we were passed
2871 in a key which only had chars 0-255, but was utf8 encoded. */
2874 /* If we found we were able to downgrade the string to bytes, then
2875 we should flag that it needs upgrading on keys or each. Also flag
2876 that we need share_hek_flags to free the string. */
2879 PERL_HASH(hash, str, len);
2880 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2884 return share_hek_flags (str, len, hash, flags);
2888 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2891 const int flags_masked = flags & HVhek_MASK;
2892 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2893 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2895 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2897 /* what follows is the moral equivalent of:
2899 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2900 hv_store(PL_strtab, str, len, NULL, hash);
2902 Can't rehash the shared string table, so not sure if it's worth
2903 counting the number of entries in the linked list
2906 /* assert(xhv_array != 0) */
2907 entry = (HvARRAY(PL_strtab))[hindex];
2908 for (;entry; entry = HeNEXT(entry)) {
2909 if (HeHASH(entry) != hash) /* strings can't be equal */
2911 if (HeKLEN(entry) != len)
2913 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2915 if (HeKFLAGS(entry) != flags_masked)
2921 /* What used to be head of the list.
2922 If this is NULL, then we're the first entry for this slot, which
2923 means we need to increate fill. */
2924 struct shared_he *new_entry;
2927 HE **const head = &HvARRAY(PL_strtab)[hindex];
2928 HE *const next = *head;
2930 /* We don't actually store a HE from the arena and a regular HEK.
2931 Instead we allocate one chunk of memory big enough for both,
2932 and put the HEK straight after the HE. This way we can find the
2933 HE directly from the HEK.
2936 Newx(k, STRUCT_OFFSET(struct shared_he,
2937 shared_he_hek.hek_key[0]) + len + 2, char);
2938 new_entry = (struct shared_he *)k;
2939 entry = &(new_entry->shared_he_he);
2940 hek = &(new_entry->shared_he_hek);
2942 Copy(str, HEK_KEY(hek), len, char);
2943 HEK_KEY(hek)[len] = 0;
2945 HEK_HASH(hek) = hash;
2946 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2948 /* Still "point" to the HEK, so that other code need not know what
2950 HeKEY_hek(entry) = hek;
2951 entry->he_valu.hent_refcount = 0;
2952 HeNEXT(entry) = next;
2955 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2956 if (!next) { /* initial entry? */
2957 } else if ( DO_HSPLIT(xhv) ) {
2958 const STRLEN oldsize = xhv->xhv_max + 1;
2959 hsplit(PL_strtab, oldsize, oldsize * 2);
2963 ++entry->he_valu.hent_refcount;
2965 if (flags & HVhek_FREEKEY)
2968 return HeKEY_hek(entry);
2972 Perl_hv_placeholders_p(pTHX_ HV *hv)
2974 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2976 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2979 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2982 Perl_die(aTHX_ "panic: hv_placeholders_p");
2985 return &(mg->mg_len);
2990 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2992 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2994 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2995 PERL_UNUSED_CONTEXT;
2997 return mg ? mg->mg_len : 0;
3001 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3003 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3005 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3010 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3011 Perl_die(aTHX_ "panic: hv_placeholders_set");
3013 /* else we don't need to add magic to record 0 placeholders. */
3017 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3022 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3024 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3029 value = &PL_sv_placeholder;
3032 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3035 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3038 case HVrhek_PV_UTF8:
3039 /* Create a string SV that directly points to the bytes in our
3041 value = newSV_type(SVt_PV);
3042 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3043 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3044 /* This stops anything trying to free it */
3045 SvLEN_set(value, 0);
3047 SvREADONLY_on(value);
3048 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3052 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
3053 (UV)he->refcounted_he_data[0]);
3059 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
3061 Generates and returns a C<HV *> representing the content of a
3062 C<refcounted_he> chain.
3063 I<flags> is currently unused and must be zero.
3068 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3072 U32 placeholders, max;
3075 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3078 /* We could chase the chain once to get an idea of the number of keys,
3079 and call ksplit. But for now we'll make a potentially inefficient
3080 hash with only 8 entries in its array. */
3085 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3086 HvARRAY(hv) = (HE**)array;
3092 U32 hash = chain->refcounted_he_hash;
3094 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3096 HE **oentry = &((HvARRAY(hv))[hash & max]);
3097 HE *entry = *oentry;
3100 for (; entry; entry = HeNEXT(entry)) {
3101 if (HeHASH(entry) == hash) {
3102 /* We might have a duplicate key here. If so, entry is older
3103 than the key we've already put in the hash, so if they are
3104 the same, skip adding entry. */
3106 const STRLEN klen = HeKLEN(entry);
3107 const char *const key = HeKEY(entry);
3108 if (klen == chain->refcounted_he_keylen
3109 && (!!HeKUTF8(entry)
3110 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3111 && memEQ(key, REF_HE_KEY(chain), klen))
3114 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3116 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3117 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3118 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3129 = share_hek_flags(REF_HE_KEY(chain),
3130 chain->refcounted_he_keylen,
3131 chain->refcounted_he_hash,
3132 (chain->refcounted_he_data[0]
3133 & (HVhek_UTF8|HVhek_WASUTF8)));
3135 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3137 value = refcounted_he_value(chain);
3138 if (value == &PL_sv_placeholder)
3140 HeVAL(entry) = value;
3142 /* Link it into the chain. */
3143 HeNEXT(entry) = *oentry;
3149 chain = chain->refcounted_he_next;
3153 clear_placeholders(hv, placeholders);
3154 HvTOTALKEYS(hv) -= placeholders;
3157 /* We could check in the loop to see if we encounter any keys with key
3158 flags, but it's probably not worth it, as this per-hash flag is only
3159 really meant as an optimisation for things like Storable. */
3161 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3167 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3169 Search along a C<refcounted_he> chain for an entry with the key specified
3170 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3171 bit set, the key octets are interpreted as UTF-8, otherwise they
3172 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3173 string, or zero if it has not been precomputed. Returns a mortal scalar
3174 representing the value associated with the key, or C<&PL_sv_placeholder>
3175 if there is no value associated with the key.
3181 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3182 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3186 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3188 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3189 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3192 return &PL_sv_placeholder;
3193 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3194 /* For searching purposes, canonicalise to Latin-1 where possible. */
3195 const char *keyend = keypv + keylen, *p;
3196 STRLEN nonascii_count = 0;
3197 for (p = keypv; p != keyend; p++) {
3198 if (! UTF8_IS_INVARIANT(*p)) {
3199 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3200 goto canonicalised_key;
3206 if (nonascii_count) {
3208 const char *p = keypv, *keyend = keypv + keylen;
3209 keylen -= nonascii_count;
3210 Newx(q, keylen, char);
3213 for (; p != keyend; p++, q++) {
3215 if (UTF8_IS_INVARIANT(c)) {
3220 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3224 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3225 canonicalised_key: ;
3227 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3229 PERL_HASH(hash, keypv, keylen);
3231 for (; chain; chain = chain->refcounted_he_next) {
3234 hash == chain->refcounted_he_hash &&
3235 keylen == chain->refcounted_he_keylen &&
3236 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3237 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3239 hash == HEK_HASH(chain->refcounted_he_hek) &&
3240 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3241 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3242 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3245 if (flags & REFCOUNTED_HE_EXISTS)
3246 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3248 ? NULL : &PL_sv_yes;
3249 return sv_2mortal(refcounted_he_value(chain));
3252 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3256 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3258 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3259 instead of a string/length pair.
3265 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3266 const char *key, U32 hash, U32 flags)
3268 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3269 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3273 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3275 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3282 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3283 SV *key, U32 hash, U32 flags)
3287 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3288 if (flags & REFCOUNTED_HE_KEY_UTF8)
3289 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3291 keypv = SvPV_const(key, keylen);
3293 flags |= REFCOUNTED_HE_KEY_UTF8;
3294 if (!hash && SvIsCOW_shared_hash(key))
3295 hash = SvSHARED_HASH(key);
3296 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3300 =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
3302 Creates a new C<refcounted_he>. This consists of a single key/value
3303 pair and a reference to an existing C<refcounted_he> chain (which may
3304 be empty), and thus forms a longer chain. When using the longer chain,
3305 the new key/value pair takes precedence over any entry for the same key
3306 further along the chain.
3308 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3309 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3310 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3311 a precomputed hash of the key string, or zero if it has not been
3314 I<value> is the scalar value to store for this key. I<value> is copied
3315 by this function, which thus does not take ownership of any reference
3316 to it, and later changes to the scalar will not be reflected in the
3317 value visible in the C<refcounted_he>. Complex types of scalar will not
3318 be stored with referential integrity, but will be coerced to strings.
3319 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3320 value is to be associated with the key; this, as with any non-null value,
3321 takes precedence over the existence of a value for the key further along
3324 I<parent> points to the rest of the C<refcounted_he> chain to be
3325 attached to the new C<refcounted_he>. This function takes ownership
3326 of one reference to I<parent>, and returns one reference to the new
3332 struct refcounted_he *
3333 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3334 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3337 STRLEN value_len = 0;
3338 const char *value_p = NULL;
3342 STRLEN key_offset = 1;
3343 struct refcounted_he *he;
3344 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3346 if (!value || value == &PL_sv_placeholder) {
3347 value_type = HVrhek_delete;
3348 } else if (SvPOK(value)) {
3349 value_type = HVrhek_PV;
3350 } else if (SvIOK(value)) {
3351 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3352 } else if (!SvOK(value)) {
3353 value_type = HVrhek_undef;
3355 value_type = HVrhek_PV;
3357 is_pv = value_type == HVrhek_PV;
3359 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3360 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3361 value_p = SvPV_const(value, value_len);
3363 value_type = HVrhek_PV_UTF8;
3364 key_offset = value_len + 2;
3366 hekflags = value_type;
3368 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3369 /* Canonicalise to Latin-1 where possible. */
3370 const char *keyend = keypv + keylen, *p;
3371 STRLEN nonascii_count = 0;
3372 for (p = keypv; p != keyend; p++) {
3373 if (! UTF8_IS_INVARIANT(*p)) {
3374 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3375 goto canonicalised_key;
3381 if (nonascii_count) {
3383 const char *p = keypv, *keyend = keypv + keylen;
3384 keylen -= nonascii_count;
3385 Newx(q, keylen, char);
3388 for (; p != keyend; p++, q++) {
3390 if (UTF8_IS_INVARIANT(c)) {
3395 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3399 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3400 canonicalised_key: ;
3402 if (flags & REFCOUNTED_HE_KEY_UTF8)
3403 hekflags |= HVhek_UTF8;
3405 PERL_HASH(hash, keypv, keylen);
3408 he = (struct refcounted_he*)
3409 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3413 he = (struct refcounted_he*)
3414 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3418 he->refcounted_he_next = parent;
3421 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3422 he->refcounted_he_val.refcounted_he_u_len = value_len;
3423 } else if (value_type == HVrhek_IV) {
3424 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3425 } else if (value_type == HVrhek_UV) {
3426 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3430 he->refcounted_he_hash = hash;
3431 he->refcounted_he_keylen = keylen;
3432 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3434 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3437 he->refcounted_he_data[0] = hekflags;
3438 he->refcounted_he_refcnt = 1;
3444 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3446 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3447 of a string/length pair.
3452 struct refcounted_he *
3453 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3454 const char *key, U32 hash, SV *value, U32 flags)
3456 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3457 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3461 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3463 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3469 struct refcounted_he *
3470 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3471 SV *key, U32 hash, SV *value, U32 flags)
3475 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3476 if (flags & REFCOUNTED_HE_KEY_UTF8)
3477 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3479 keypv = SvPV_const(key, keylen);
3481 flags |= REFCOUNTED_HE_KEY_UTF8;
3482 if (!hash && SvIsCOW_shared_hash(key))
3483 hash = SvSHARED_HASH(key);
3484 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3488 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3490 Decrements the reference count of a C<refcounted_he> by one. If the
3491 reference count reaches zero the structure's memory is freed, which
3492 (recursively) causes a reduction of its parent C<refcounted_he>'s
3493 reference count. It is safe to pass a null pointer to this function:
3494 no action occurs in this case.
3500 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3504 PERL_UNUSED_CONTEXT;
3507 struct refcounted_he *copy;
3511 new_count = --he->refcounted_he_refcnt;
3512 HINTS_REFCNT_UNLOCK;
3518 #ifndef USE_ITHREADS
3519 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3522 he = he->refcounted_he_next;
3523 PerlMemShared_free(copy);
3528 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3530 Increment the reference count of a C<refcounted_he>. The pointer to the
3531 C<refcounted_he> is also returned. It is safe to pass a null pointer
3532 to this function: no action occurs and a null pointer is returned.
3537 struct refcounted_he *
3538 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3543 PERL_UNUSED_CONTEXT;
3546 he->refcounted_he_refcnt++;
3547 HINTS_REFCNT_UNLOCK;
3553 =for apidoc cop_fetch_label
3555 Returns the label attached to a cop.
3556 The flags pointer may be set to C<SVf_UTF8> or 0.
3561 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3564 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3565 struct refcounted_he *const chain = cop->cop_hints_hash;
3567 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3568 PERL_UNUSED_CONTEXT;
3573 if (chain->refcounted_he_keylen != 1)
3575 if (*REF_HE_KEY(chain) != ':')
3578 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3580 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3583 /* Stop anyone trying to really mess us up by adding their own value for
3585 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3586 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3590 *len = chain->refcounted_he_val.refcounted_he_u_len;
3592 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3593 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3595 return chain->refcounted_he_data + 1;
3599 =for apidoc cop_store_label
3601 Save a label into a C<cop_hints_hash>.
3602 You need to set flags to C<SVf_UTF8>
3609 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3613 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3615 if (flags & ~(SVf_UTF8))
3616 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3618 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3619 if (flags & SVf_UTF8)
3622 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3626 =for apidoc hv_assert
3628 Check that a hash is in an internally consistent state.
3636 Perl_hv_assert(pTHX_ HV *hv)
3641 int placeholders = 0;
3644 const I32 riter = HvRITER_get(hv);
3645 HE *eiter = HvEITER_get(hv);
3647 PERL_ARGS_ASSERT_HV_ASSERT;
3649 (void)hv_iterinit(hv);
3651 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3652 /* sanity check the values */
3653 if (HeVAL(entry) == &PL_sv_placeholder)
3657 /* sanity check the keys */
3658 if (HeSVKEY(entry)) {
3659 NOOP; /* Don't know what to check on SV keys. */
3660 } else if (HeKUTF8(entry)) {
3662 if (HeKWASUTF8(entry)) {
3663 PerlIO_printf(Perl_debug_log,
3664 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3665 (int) HeKLEN(entry), HeKEY(entry));
3668 } else if (HeKWASUTF8(entry))
3671 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3672 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3673 const int nhashkeys = HvUSEDKEYS(hv);
3674 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3676 if (nhashkeys != real) {
3677 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3680 if (nhashplaceholders != placeholders) {
3681 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3685 if (withflags && ! HvHASKFLAGS(hv)) {
3686 PerlIO_printf(Perl_debug_log,
3687 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3692 sv_dump(MUTABLE_SV(hv));
3694 HvRITER_set(hv, riter); /* Restore hash iterator state */
3695 HvEITER_set(hv, eiter);
3702 * c-indentation-style: bsd
3704 * indent-tabs-mode: nil
3707 * ex: set ts=8 sts=4 sw=4 et: