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 /* we split when we collide and we have a load factor over 0.667.
38 * NOTE if you change this formula so we split earlier than previously
39 * you MUST change the logic in hv_ksplit()
41 #define DO_HSPLIT(xhv) ( ((xhv)->xhv_keys + ((xhv)->xhv_keys >> 1)) > (xhv)->xhv_max )
42 #define HV_FILL_THRESHOLD 31
44 static const char S_strtab_error[]
45 = "Cannot modify shared string table in hv_%s";
49 #define new_HE() (HE*)safemalloc(sizeof(HE))
50 #define del_HE(p) safefree((char*)p)
58 void ** const root = &PL_body_roots[HE_SVSLOT];
61 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
68 #define new_HE() new_he()
71 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
72 PL_body_roots[HE_SVSLOT] = p; \
80 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
82 const int flags_masked = flags & HVhek_MASK;
86 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
88 Newx(k, HEK_BASESIZE + len + 2, char);
90 Copy(str, HEK_KEY(hek), len, char);
91 HEK_KEY(hek)[len] = 0;
94 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
96 if (flags & HVhek_FREEKEY)
101 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
105 Perl_free_tied_hv_pool(pTHX)
107 HE *he = PL_hv_fetch_ent_mh;
110 Safefree(HeKEY_hek(he));
114 PL_hv_fetch_ent_mh = NULL;
117 #if defined(USE_ITHREADS)
119 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
123 PERL_ARGS_ASSERT_HEK_DUP;
124 PERL_UNUSED_ARG(param);
129 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
131 /* We already shared this hash key. */
132 (void)share_hek_hek(shared);
136 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
137 HEK_HASH(source), HEK_FLAGS(source));
138 ptr_table_store(PL_ptr_table, source, shared);
144 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
148 PERL_ARGS_ASSERT_HE_DUP;
152 /* look for it in the table first */
153 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
157 /* create anew and remember what it is */
159 ptr_table_store(PL_ptr_table, e, ret);
161 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
162 if (HeKLEN(e) == HEf_SVKEY) {
164 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
165 HeKEY_hek(ret) = (HEK*)k;
166 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
169 /* This is hek_dup inlined, which seems to be important for speed
171 HEK * const source = HeKEY_hek(e);
172 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
175 /* We already shared this hash key. */
176 (void)share_hek_hek(shared);
180 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
181 HEK_HASH(source), HEK_FLAGS(source));
182 ptr_table_store(PL_ptr_table, source, shared);
184 HeKEY_hek(ret) = shared;
187 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
189 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
192 #endif /* USE_ITHREADS */
195 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
198 SV * const sv = sv_newmortal();
200 PERL_ARGS_ASSERT_HV_NOTALLOWED;
202 if (!(flags & HVhek_FREEKEY)) {
203 sv_setpvn(sv, key, klen);
206 /* Need to free saved eventually assign to mortal SV */
207 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
208 sv_usepvn(sv, (char *) key, klen);
210 if (flags & HVhek_UTF8) {
213 Perl_croak(aTHX_ msg, SVfARG(sv));
216 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
222 Stores an SV in a hash. The hash key is specified as C<key> and the
223 absolute value of C<klen> is the length of the key. If C<klen> is
224 negative the key is assumed to be in UTF-8-encoded Unicode. The
225 C<hash> parameter is the precomputed hash value; if it is zero then
226 Perl will compute it.
228 The return value will be
229 C<NULL> if the operation failed or if the value did not need to be actually
230 stored within the hash (as in the case of tied hashes). Otherwise it can
231 be dereferenced to get the original C<SV*>. Note that the caller is
232 responsible for suitably incrementing the reference count of C<val> before
233 the call, and decrementing it if the function returned C<NULL>. Effectively
234 a successful C<hv_store> takes ownership of one reference to C<val>. This is
235 usually what you want; a newly created SV has a reference count of one, so
236 if all your code does is create SVs then store them in a hash, C<hv_store>
237 will own the only reference to the new SV, and your code doesn't need to do
238 anything further to tidy up. C<hv_store> is not implemented as a call to
239 C<hv_store_ent>, and does not create a temporary SV for the key, so if your
240 key data is not already in SV form then use C<hv_store> in preference to
243 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
244 information on how to use this function on tied hashes.
246 =for apidoc hv_store_ent
248 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
249 parameter is the precomputed hash value; if it is zero then Perl will
250 compute it. The return value is the new hash entry so created. It will be
251 C<NULL> if the operation failed or if the value did not need to be actually
252 stored within the hash (as in the case of tied hashes). Otherwise the
253 contents of the return value can be accessed using the C<He?> macros
254 described here. Note that the caller is responsible for suitably
255 incrementing the reference count of C<val> before the call, and
256 decrementing it if the function returned NULL. Effectively a successful
257 C<hv_store_ent> takes ownership of one reference to C<val>. This is
258 usually what you want; a newly created SV has a reference count of one, so
259 if all your code does is create SVs then store them in a hash, C<hv_store>
260 will own the only reference to the new SV, and your code doesn't need to do
261 anything further to tidy up. Note that C<hv_store_ent> only reads the C<key>;
262 unlike C<val> it does not take ownership of it, so maintaining the correct
263 reference count on C<key> is entirely the caller's responsibility. The reason
264 it does not take ownership, is that C<key> is not used after this function
265 returns, and so can be freed immediately. C<hv_store>
266 is not implemented as a call to C<hv_store_ent>, and does not create a temporary
267 SV for the key, so if your key data is not already in SV form then use
268 C<hv_store> in preference to C<hv_store_ent>.
270 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
271 information on how to use this function on tied hashes.
273 =for apidoc hv_exists
275 Returns a boolean indicating whether the specified hash key exists. The
276 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.
281 Returns the SV which corresponds to the specified key in the hash.
282 The absolute value of C<klen> is the length of the key. If C<klen> is
283 negative the key is assumed to be in UTF-8-encoded Unicode. If
284 C<lval> is set then the fetch will be part of a store. This means that if
285 there is no value in the hash associated with the given key, then one is
286 created and a pointer to it is returned. The C<SV*> it points to can be
287 assigned to. But always check that the
288 return value is non-null before dereferencing it to an C<SV*>.
290 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
291 information on how to use this function on tied hashes.
293 =for apidoc hv_exists_ent
295 Returns a boolean indicating whether
296 the specified hash key exists. C<hash>
297 can be a valid precomputed hash value, or 0 to ask for it to be
303 /* returns an HE * structure with the all fields set */
304 /* note that hent_val will be a mortal sv for MAGICAL hashes */
306 =for apidoc hv_fetch_ent
308 Returns the hash entry which corresponds to the specified key in the hash.
309 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
310 if you want the function to compute it. IF C<lval> is set then the fetch
311 will be part of a store. Make sure the return value is non-null before
312 accessing it. The return value when C<hv> is a tied hash is a pointer to a
313 static location, so be sure to make a copy of the structure if you need to
316 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
317 information on how to use this function on tied hashes.
322 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
324 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
325 const int action, SV *val, const U32 hash)
330 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
339 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
343 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
344 int flags, int action, SV *val, U32 hash)
354 const int return_svp = action & HV_FETCH_JUST_SV;
355 HEK *keysv_hek = NULL;
359 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
362 assert(SvTYPE(hv) == SVt_PVHV);
364 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
366 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
367 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
368 if (uf->uf_set == NULL) {
369 SV* obj = mg->mg_obj;
372 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
373 ((flags & HVhek_UTF8)
377 mg->mg_obj = keysv; /* pass key */
378 uf->uf_index = action; /* pass action */
379 magic_getuvar(MUTABLE_SV(hv), mg);
380 keysv = mg->mg_obj; /* may have changed */
383 /* If the key may have changed, then we need to invalidate
384 any passed-in computed hash value. */
390 if (flags & HVhek_FREEKEY)
392 key = SvPV_const(keysv, klen);
393 is_utf8 = (SvUTF8(keysv) != 0);
394 if (SvIsCOW_shared_hash(keysv)) {
395 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
397 flags = is_utf8 ? HVhek_UTF8 : 0;
400 is_utf8 = cBOOL(flags & HVhek_UTF8);
403 if (action & HV_DELETE) {
404 return (void *) hv_delete_common(hv, keysv, key, klen,
405 flags, action, hash);
408 xhv = (XPVHV*)SvANY(hv);
410 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
411 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
412 || SvGMAGICAL((const SV *)hv))
414 /* FIXME should be able to skimp on the HE/HEK here when
415 HV_FETCH_JUST_SV is true. */
417 keysv = newSVpvn_utf8(key, klen, is_utf8);
419 keysv = newSVsv(keysv);
422 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
424 /* grab a fake HE/HEK pair from the pool or make a new one */
425 entry = PL_hv_fetch_ent_mh;
427 PL_hv_fetch_ent_mh = HeNEXT(entry);
431 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
432 HeKEY_hek(entry) = (HEK*)k;
434 HeNEXT(entry) = NULL;
435 HeSVKEY_set(entry, keysv);
437 sv_upgrade(sv, SVt_PVLV);
439 /* so we can free entry when freeing sv */
440 LvTARG(sv) = MUTABLE_SV(entry);
442 /* XXX remove at some point? */
443 if (flags & HVhek_FREEKEY)
447 return entry ? (void *) &HeVAL(entry) : NULL;
449 return (void *) entry;
451 #ifdef ENV_IS_CASELESS
452 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
454 for (i = 0; i < klen; ++i)
455 if (isLOWER(key[i])) {
456 /* Would be nice if we had a routine to do the
457 copy and upercase in a single pass through. */
458 const char * const nkey = strupr(savepvn(key,klen));
459 /* Note that this fetch is for nkey (the uppercased
460 key) whereas the store is for key (the original) */
461 void *result = hv_common(hv, NULL, nkey, klen,
462 HVhek_FREEKEY, /* free nkey */
463 0 /* non-LVAL fetch */
464 | HV_DISABLE_UVAR_XKEY
467 0 /* compute hash */);
468 if (!result && (action & HV_FETCH_LVALUE)) {
469 /* This call will free key if necessary.
470 Do it this way to encourage compiler to tail
472 result = hv_common(hv, keysv, key, klen, flags,
474 | HV_DISABLE_UVAR_XKEY
478 if (flags & HVhek_FREEKEY)
486 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
487 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
488 || SvGMAGICAL((const SV *)hv)) {
489 /* I don't understand why hv_exists_ent has svret and sv,
490 whereas hv_exists only had one. */
491 SV * const svret = sv_newmortal();
494 if (keysv || is_utf8) {
496 keysv = newSVpvn_utf8(key, klen, TRUE);
498 keysv = newSVsv(keysv);
500 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
502 mg_copy(MUTABLE_SV(hv), sv, key, klen);
504 if (flags & HVhek_FREEKEY)
507 MAGIC * const mg = mg_find(sv, PERL_MAGIC_tiedelem);
509 magic_existspack(svret, mg);
511 /* This cast somewhat evil, but I'm merely using NULL/
512 not NULL to return the boolean exists.
513 And I know hv is not NULL. */
514 return SvTRUE_NN(svret) ? (void *)hv : NULL;
516 #ifdef ENV_IS_CASELESS
517 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
518 /* XXX This code isn't UTF8 clean. */
519 char * const keysave = (char * const)key;
520 /* Will need to free this, so set FREEKEY flag. */
521 key = savepvn(key,klen);
522 key = (const char*)strupr((char*)key);
527 if (flags & HVhek_FREEKEY) {
530 flags |= HVhek_FREEKEY;
534 else if (action & HV_FETCH_ISSTORE) {
537 hv_magic_check (hv, &needs_copy, &needs_store);
539 const bool save_taint = TAINT_get;
540 if (keysv || is_utf8) {
542 keysv = newSVpvn_utf8(key, klen, TRUE);
545 TAINT_set(SvTAINTED(keysv));
546 keysv = sv_2mortal(newSVsv(keysv));
547 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
549 mg_copy(MUTABLE_SV(hv), val, key, klen);
552 TAINT_IF(save_taint);
553 #ifdef NO_TAINT_SUPPORT
554 PERL_UNUSED_VAR(save_taint);
557 if (flags & HVhek_FREEKEY)
561 #ifdef ENV_IS_CASELESS
562 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
563 /* XXX This code isn't UTF8 clean. */
564 const char *keysave = key;
565 /* Will need to free this, so set FREEKEY flag. */
566 key = savepvn(key,klen);
567 key = (const char*)strupr((char*)key);
572 if (flags & HVhek_FREEKEY) {
575 flags |= HVhek_FREEKEY;
583 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
584 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
585 || (SvRMAGICAL((const SV *)hv)
586 && mg_find((const SV *)hv, PERL_MAGIC_env))
591 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
593 HvARRAY(hv) = (HE**)array;
595 #ifdef DYNAMIC_ENV_FETCH
596 else if (action & HV_FETCH_ISEXISTS) {
597 /* for an %ENV exists, if we do an insert it's by a recursive
598 store call, so avoid creating HvARRAY(hv) right now. */
602 /* XXX remove at some point? */
603 if (flags & HVhek_FREEKEY)
610 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
611 char * const keysave = (char *)key;
612 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
616 flags &= ~HVhek_UTF8;
617 if (key != keysave) {
618 if (flags & HVhek_FREEKEY)
620 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
621 /* If the caller calculated a hash, it was on the sequence of
622 octets that are the UTF-8 form. We've now changed the sequence
623 of octets stored to that of the equivalent byte representation,
624 so the hash we need is different. */
629 if (keysv && (SvIsCOW_shared_hash(keysv))) {
631 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
632 hash = SvSHARED_HASH(keysv);
635 PERL_HASH(hash, key, klen);
637 masked_flags = (flags & HVhek_MASK);
639 #ifdef DYNAMIC_ENV_FETCH
640 if (!HvARRAY(hv)) entry = NULL;
644 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
651 /* keysv is actually a HEK in disguise, so we can match just by
652 * comparing the HEK pointers in the HE chain. There is a slight
653 * caveat: on something like "\x80", which has both plain and utf8
654 * representations, perl's hashes do encoding-insensitive lookups,
655 * but preserve the encoding of the stored key. Thus a particular
656 * key could map to two different HEKs in PL_strtab. We only
657 * conclude 'not found' if all the flags are the same; otherwise
658 * we fall back to a full search (this should only happen in rare
661 int keysv_flags = HEK_FLAGS(keysv_hek);
662 HE *orig_entry = entry;
664 for (; entry; entry = HeNEXT(entry)) {
665 HEK *hek = HeKEY_hek(entry);
666 if (hek == keysv_hek)
668 if (HEK_FLAGS(hek) != keysv_flags)
669 break; /* need to do full match */
673 /* failed on shortcut - do full search loop */
677 for (; entry; entry = HeNEXT(entry)) {
678 if (HeHASH(entry) != hash) /* strings can't be equal */
680 if (HeKLEN(entry) != (I32)klen)
682 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
684 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
688 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
689 if (HeKFLAGS(entry) != masked_flags) {
690 /* We match if HVhek_UTF8 bit in our flags and hash key's
691 match. But if entry was set previously with HVhek_WASUTF8
692 and key now doesn't (or vice versa) then we should change
693 the key's flag, as this is assignment. */
694 if (HvSHAREKEYS(hv)) {
695 /* Need to swap the key we have for a key with the flags we
696 need. As keys are shared we can't just write to the
697 flag, so we share the new one, unshare the old one. */
698 HEK * const new_hek = share_hek_flags(key, klen, hash,
700 unshare_hek (HeKEY_hek(entry));
701 HeKEY_hek(entry) = new_hek;
703 else if (hv == PL_strtab) {
704 /* PL_strtab is usually the only hash without HvSHAREKEYS,
705 so putting this test here is cheap */
706 if (flags & HVhek_FREEKEY)
708 Perl_croak(aTHX_ S_strtab_error,
709 action & HV_FETCH_LVALUE ? "fetch" : "store");
712 HeKFLAGS(entry) = masked_flags;
713 if (masked_flags & HVhek_ENABLEHVKFLAGS)
716 if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* yes, can store into placeholder slot */
718 if (action & HV_FETCH_LVALUE) {
720 /* This preserves behaviour with the old hv_fetch
721 implementation which at this point would bail out
722 with a break; (at "if we find a placeholder, we
723 pretend we haven't found anything")
725 That break mean that if a placeholder were found, it
726 caused a call into hv_store, which in turn would
727 check magic, and if there is no magic end up pretty
728 much back at this point (in hv_store's code). */
731 /* LVAL fetch which actually needs a store. */
733 HvPLACEHOLDERS(hv)--;
736 if (val != &PL_sv_placeholder)
737 HvPLACEHOLDERS(hv)--;
740 } else if (action & HV_FETCH_ISSTORE) {
741 SvREFCNT_dec(HeVAL(entry));
744 } else if (HeVAL(entry) == &PL_sv_placeholder) {
745 /* if we find a placeholder, we pretend we haven't found
749 if (flags & HVhek_FREEKEY)
752 return (void *) &HeVAL(entry);
758 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
759 if (!(action & HV_FETCH_ISSTORE)
760 && SvRMAGICAL((const SV *)hv)
761 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
763 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
765 sv = newSVpvn(env,len);
767 return hv_common(hv, keysv, key, klen, flags,
768 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
774 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
775 hv_notallowed(flags, key, klen,
776 "Attempt to access disallowed key '%" SVf "' in"
777 " a restricted hash");
779 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
780 /* Not doing some form of store, so return failure. */
781 if (flags & HVhek_FREEKEY)
785 if (action & HV_FETCH_LVALUE) {
786 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
788 /* At this point the old hv_fetch code would call to hv_store,
789 which in turn might do some tied magic. So we need to make that
790 magic check happen. */
791 /* gonna assign to this, so it better be there */
792 /* If a fetch-as-store fails on the fetch, then the action is to
793 recurse once into "hv_store". If we didn't do this, then that
794 recursive call would call the key conversion routine again.
795 However, as we replace the original key with the converted
796 key, this would result in a double conversion, which would show
797 up as a bug if the conversion routine is not idempotent.
798 Hence the use of HV_DISABLE_UVAR_XKEY. */
799 return hv_common(hv, keysv, key, klen, flags,
800 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
802 /* XXX Surely that could leak if the fetch-was-store fails?
803 Just like the hv_fetch. */
807 /* Welcome to hv_store... */
810 /* Not sure if we can get here. I think the only case of oentry being
811 NULL is for %ENV with dynamic env fetch. But that should disappear
812 with magic in the previous code. */
815 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
817 HvARRAY(hv) = (HE**)array;
820 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
823 /* share_hek_flags will do the free for us. This might be considered
826 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
827 else if (hv == PL_strtab) {
828 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
829 this test here is cheap */
830 if (flags & HVhek_FREEKEY)
832 Perl_croak(aTHX_ S_strtab_error,
833 action & HV_FETCH_LVALUE ? "fetch" : "store");
835 else /* gotta do the real thing */
836 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
839 #ifdef PERL_HASH_RANDOMIZE_KEYS
840 /* This logic semi-randomizes the insert order in a bucket.
841 * Either we insert into the top, or the slot below the top,
842 * making it harder to see if there is a collision. We also
843 * reset the iterator randomizer if there is one.
845 in_collision = *oentry != NULL;
846 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
848 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
849 if ( PL_hash_rand_bits & 1 ) {
850 HeNEXT(entry) = HeNEXT(*oentry);
851 HeNEXT(*oentry) = entry;
853 HeNEXT(entry) = *oentry;
859 HeNEXT(entry) = *oentry;
862 #ifdef PERL_HASH_RANDOMIZE_KEYS
864 /* Currently this makes various tests warn in annoying ways.
865 * So Silenced for now. - Yves | bogus end of comment =>* /
866 if (HvAUX(hv)->xhv_riter != -1) {
867 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
868 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
873 if (PL_HASH_RAND_BITS_ENABLED) {
874 if (PL_HASH_RAND_BITS_ENABLED == 1)
875 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
876 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
878 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
882 if (val == &PL_sv_placeholder)
883 HvPLACEHOLDERS(hv)++;
884 if (masked_flags & HVhek_ENABLEHVKFLAGS)
887 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
888 if ( in_collision && DO_HSPLIT(xhv) ) {
889 const STRLEN oldsize = xhv->xhv_max + 1;
890 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
892 if (items /* hash has placeholders */
893 && !SvREADONLY(hv) /* but is not a restricted hash */) {
894 /* If this hash previously was a "restricted hash" and had
895 placeholders, but the "restricted" flag has been turned off,
896 then the placeholders no longer serve any useful purpose.
897 However, they have the downsides of taking up RAM, and adding
898 extra steps when finding used values. It's safe to clear them
899 at this point, even though Storable rebuilds restricted hashes by
900 putting in all the placeholders (first) before turning on the
901 readonly flag, because Storable always pre-splits the hash.
902 If we're lucky, then we may clear sufficient placeholders to
903 avoid needing to split the hash at all. */
904 clear_placeholders(hv, items);
906 hsplit(hv, oldsize, oldsize * 2);
908 hsplit(hv, oldsize, oldsize * 2);
912 return entry ? (void *) &HeVAL(entry) : NULL;
914 return (void *) entry;
918 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
920 const MAGIC *mg = SvMAGIC(hv);
922 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
927 if (isUPPER(mg->mg_type)) {
929 if (mg->mg_type == PERL_MAGIC_tied) {
930 *needs_store = FALSE;
931 return; /* We've set all there is to set. */
934 mg = mg->mg_moremagic;
939 =for apidoc hv_scalar
941 Evaluates the hash in scalar context and returns the result.
943 When the hash is tied dispatches through to the SCALAR method,
944 otherwise returns a mortal SV containing the number of keys
947 Note, prior to 5.25 this function returned what is now
948 returned by the hv_bucket_ratio() function.
954 Perl_hv_scalar(pTHX_ HV *hv)
958 PERL_ARGS_ASSERT_HV_SCALAR;
960 if (SvRMAGICAL(hv)) {
961 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
963 return magic_scalarpack(hv, mg);
967 sv_setuv(sv, HvUSEDKEYS(hv));
974 hv_pushkv(): push all the keys and/or values of a hash onto the stack.
975 The rough Perl equivalents:
980 Resets the hash's iterator.
982 flags : 1 = push keys
984 1|2 = push keys and values
985 XXX use symbolic flag constants at some point?
986 I might unroll the non-tied hv_iternext() in here at some point - DAPM
990 Perl_hv_pushkv(pTHX_ HV *hv, U32 flags)
993 bool tied = SvRMAGICAL(hv) && (mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied)
994 #ifdef DYNAMIC_ENV_FETCH /* might not know number of keys yet */
995 || mg_find(MUTABLE_SV(hv), PERL_MAGIC_env)
1000 PERL_ARGS_ASSERT_HV_PUSHKV;
1001 assert(flags); /* must be pushing at least one of keys and values */
1003 (void)hv_iterinit(hv);
1006 SSize_t ext = (flags == 3) ? 2 : 1;
1007 while ((entry = hv_iternext(hv))) {
1010 PUSHs(hv_iterkeysv(entry));
1012 PUSHs(hv_iterval(hv, entry));
1016 Size_t nkeys = HvUSEDKEYS(hv);
1022 /* 2*nkeys() should never be big enough to truncate or wrap */
1023 assert(nkeys <= (SSize_t_MAX >> 1));
1024 ext = nkeys * ((flags == 3) ? 2 : 1);
1026 EXTEND_MORTAL(nkeys);
1029 while ((entry = hv_iternext(hv))) {
1031 SV *keysv = newSVhek(HeKEY_hek(entry));
1033 PL_tmps_stack[++PL_tmps_ix] = keysv;
1037 PUSHs(HeVAL(entry));
1046 =for apidoc hv_bucket_ratio
1048 If the hash is tied dispatches through to the SCALAR tied method,
1049 otherwise if the hash contains no keys returns 0, otherwise returns
1050 a mortal sv containing a string specifying the number of used buckets,
1051 followed by a slash, followed by the number of available buckets.
1053 This function is expensive, it must scan all of the buckets
1054 to determine which are used, and the count is NOT cached.
1055 In a large hash this could be a lot of buckets.
1061 Perl_hv_bucket_ratio(pTHX_ HV *hv)
1065 PERL_ARGS_ASSERT_HV_BUCKET_RATIO;
1067 if (SvRMAGICAL(hv)) {
1068 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
1070 return magic_scalarpack(hv, mg);
1073 if (HvUSEDKEYS((HV *)hv)) {
1074 sv = sv_newmortal();
1075 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
1076 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
1085 =for apidoc hv_delete
1087 Deletes a key/value pair in the hash. The value's SV is removed from
1088 the hash, made mortal, and returned to the caller. The absolute
1089 value of C<klen> is the length of the key. If C<klen> is negative the
1090 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
1091 will normally be zero; if set to C<G_DISCARD> then C<NULL> will be returned.
1092 C<NULL> will also be returned if the key is not found.
1094 =for apidoc hv_delete_ent
1096 Deletes a key/value pair in the hash. The value SV is removed from the hash,
1097 made mortal, and returned to the caller. The C<flags> value will normally be
1098 zero; if set to C<G_DISCARD> then C<NULL> will be returned. C<NULL> will also
1099 be returned if the key is not found. C<hash> can be a valid precomputed hash
1100 value, or 0 to ask for it to be computed.
1106 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
1107 int k_flags, I32 d_flags, U32 hash)
1114 bool is_utf8 = cBOOL(k_flags & HVhek_UTF8);
1116 HEK *keysv_hek = NULL;
1117 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1122 if (SvRMAGICAL(hv)) {
1125 hv_magic_check (hv, &needs_copy, &needs_store);
1129 entry = (HE *) hv_common(hv, keysv, key, klen,
1130 k_flags & ~HVhek_FREEKEY,
1131 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1133 sv = entry ? HeVAL(entry) : NULL;
1135 if (SvMAGICAL(sv)) {
1139 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1140 /* No longer an element */
1141 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1144 return NULL; /* element cannot be deleted */
1146 #ifdef ENV_IS_CASELESS
1147 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1148 /* XXX This code isn't UTF8 clean. */
1149 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1150 if (k_flags & HVhek_FREEKEY) {
1153 key = strupr(SvPVX(keysv));
1162 xhv = (XPVHV*)SvANY(hv);
1166 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1167 const char * const keysave = key;
1168 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1171 k_flags |= HVhek_UTF8;
1173 k_flags &= ~HVhek_UTF8;
1174 if (key != keysave) {
1175 if (k_flags & HVhek_FREEKEY) {
1176 /* This shouldn't happen if our caller does what we expect,
1177 but strictly the API allows it. */
1180 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1182 HvHASKFLAGS_on(MUTABLE_SV(hv));
1185 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1186 if (HvSHAREKEYS(hv))
1187 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1188 hash = SvSHARED_HASH(keysv);
1191 PERL_HASH(hash, key, klen);
1193 masked_flags = (k_flags & HVhek_MASK);
1195 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1202 /* keysv is actually a HEK in disguise, so we can match just by
1203 * comparing the HEK pointers in the HE chain. There is a slight
1204 * caveat: on something like "\x80", which has both plain and utf8
1205 * representations, perl's hashes do encoding-insensitive lookups,
1206 * but preserve the encoding of the stored key. Thus a particular
1207 * key could map to two different HEKs in PL_strtab. We only
1208 * conclude 'not found' if all the flags are the same; otherwise
1209 * we fall back to a full search (this should only happen in rare
1212 int keysv_flags = HEK_FLAGS(keysv_hek);
1214 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1215 HEK *hek = HeKEY_hek(entry);
1216 if (hek == keysv_hek)
1218 if (HEK_FLAGS(hek) != keysv_flags)
1219 break; /* need to do full match */
1223 /* failed on shortcut - do full search loop */
1224 oentry = first_entry;
1228 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1229 if (HeHASH(entry) != hash) /* strings can't be equal */
1231 if (HeKLEN(entry) != (I32)klen)
1233 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1235 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1239 if (hv == PL_strtab) {
1240 if (k_flags & HVhek_FREEKEY)
1242 Perl_croak(aTHX_ S_strtab_error, "delete");
1245 /* if placeholder is here, it's already been deleted.... */
1246 if (HeVAL(entry) == &PL_sv_placeholder) {
1247 if (k_flags & HVhek_FREEKEY)
1251 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1252 hv_notallowed(k_flags, key, klen,
1253 "Attempt to delete readonly key '%" SVf "' from"
1254 " a restricted hash");
1256 if (k_flags & HVhek_FREEKEY)
1259 /* If this is a stash and the key ends with ::, then someone is
1260 * deleting a package.
1262 if (HeVAL(entry) && HvENAME_get(hv)) {
1263 gv = (GV *)HeVAL(entry);
1264 if (keysv) key = SvPV(keysv, klen);
1266 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1268 (klen == 1 && key[0] == ':')
1270 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1271 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1272 && HvENAME_get(stash)) {
1273 /* A previous version of this code checked that the
1274 * GV was still in the symbol table by fetching the
1275 * GV with its name. That is not necessary (and
1276 * sometimes incorrect), as HvENAME cannot be set
1277 * on hv if it is not in the symtab. */
1279 /* Hang on to it for a bit. */
1280 SvREFCNT_inc_simple_void_NN(
1281 sv_2mortal((SV *)gv)
1284 else if (memEQs(key, klen, "ISA") && GvAV(gv)) {
1286 MAGIC *mg = mg_find((SV*)isa, PERL_MAGIC_isa);
1290 if (mg->mg_obj == (SV*)gv) {
1291 /* This is the only stash this ISA was used for.
1292 * The isaelem magic asserts if there's no
1293 * isa magic on the array, so explicitly
1294 * remove the magic on both the array and its
1295 * elements. @ISA shouldn't be /too/ large.
1300 end = svp + (AvFILLp(isa)+1);
1303 mg_free_type(*svp, PERL_MAGIC_isaelem);
1306 mg_free_type((SV*)GvAV(gv), PERL_MAGIC_isa);
1309 /* mg_obj is an array of stashes
1310 Note that the array doesn't keep a reference
1311 count on the stashes.
1313 AV *av = (AV*)mg->mg_obj;
1318 assert(SvTYPE(mg->mg_obj) == SVt_PVAV);
1320 /* remove the stash from the magic array */
1321 arrayp = svp = AvARRAY(av);
1322 items = AvFILLp(av) + 1;
1324 assert(*arrayp == (SV *)gv);
1326 /* avoid a double free on the last stash */
1328 /* The magic isn't MGf_REFCOUNTED, so release
1329 * the array manually.
1331 SvREFCNT_dec_NN(av);
1336 if (*svp == (SV*)gv)
1340 index = svp - arrayp;
1341 assert(index >= 0 && index <= AvFILLp(av));
1342 if (index < AvFILLp(av)) {
1343 arrayp[index] = arrayp[AvFILLp(av)];
1345 arrayp[AvFILLp(av)] = NULL;
1353 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1354 HeVAL(entry) = &PL_sv_placeholder;
1356 /* deletion of method from stash */
1357 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1359 mro_method_changed_in(hv);
1363 * If a restricted hash, rather than really deleting the entry, put
1364 * a placeholder there. This marks the key as being "approved", so
1365 * we can still access via not-really-existing key without raising
1369 /* We'll be saving this slot, so the number of allocated keys
1370 * doesn't go down, but the number placeholders goes up */
1371 HvPLACEHOLDERS(hv)++;
1373 *oentry = HeNEXT(entry);
1374 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1377 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1378 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1379 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1380 hv_free_ent(hv, entry);
1382 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1383 if (xhv->xhv_keys == 0)
1384 HvHASKFLAGS_off(hv);
1387 if (d_flags & G_DISCARD) {
1392 if (mro_changes == 1) mro_isa_changed_in(hv);
1393 else if (mro_changes == 2)
1394 mro_package_moved(NULL, stash, gv, 1);
1400 if (SvREADONLY(hv)) {
1401 hv_notallowed(k_flags, key, klen,
1402 "Attempt to delete disallowed key '%" SVf "' from"
1403 " a restricted hash");
1406 if (k_flags & HVhek_FREEKEY)
1413 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1416 char *a = (char*) HvARRAY(hv);
1420 /* already have an HvAUX(hv) so we have to move it */
1422 /* no HvAUX() but array we are going to allocate is large enough
1423 * there is no point in saving the space for the iterator, and
1424 * speeds up later traversals. */
1425 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1428 PERL_ARGS_ASSERT_HSPLIT;
1431 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1432 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1438 #ifdef PERL_HASH_RANDOMIZE_KEYS
1439 /* the idea of this is that we create a "random" value by hashing the address of
1440 * the array, we then use the low bit to decide if we insert at the top, or insert
1441 * second from top. After each such insert we rotate the hashed value. So we can
1442 * use the same hashed value over and over, and in normal build environments use
1443 * very few ops to do so. ROTL32() should produce a single machine operation. */
1444 if (PL_HASH_RAND_BITS_ENABLED) {
1445 if (PL_HASH_RAND_BITS_ENABLED == 1)
1446 PL_hash_rand_bits += ptr_hash((PTRV)a);
1447 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1450 HvARRAY(hv) = (HE**) a;
1451 HvMAX(hv) = newsize - 1;
1452 /* before we zero the newly added memory, we
1453 * need to deal with the aux struct that may be there
1454 * or have been allocated by us*/
1456 struct xpvhv_aux *const dest
1457 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1459 /* alread have an aux, copy the old one in place. */
1460 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1461 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1462 #ifdef PERL_HASH_RANDOMIZE_KEYS
1463 dest->xhv_rand = (U32)PL_hash_rand_bits;
1466 /* no existing aux structure, but we allocated space for one
1467 * so initialize it properly. This unrolls hv_auxinit() a bit,
1468 * since we have to do the realloc anyway. */
1469 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1470 #ifdef PERL_HASH_RANDOMIZE_KEYS
1471 dest->xhv_rand = (U32)PL_hash_rand_bits;
1473 /* this is the "non realloc" part of the hv_auxinit() */
1474 (void)hv_auxinit_internal(dest);
1475 /* Turn on the OOK flag */
1479 /* now we can safely clear the second half */
1480 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1482 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1488 HE **oentry = aep + i;
1491 if (!entry) /* non-existent */
1494 U32 j = (HeHASH(entry) & newsize);
1496 *oentry = HeNEXT(entry);
1497 #ifdef PERL_HASH_RANDOMIZE_KEYS
1498 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1499 * insert to top, otherwise rotate the bucket rand 1 bit,
1500 * and use the new low bit to decide if we insert at top,
1501 * or next from top. IOW, we only rotate on a collision.*/
1502 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1503 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1504 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1505 if (PL_hash_rand_bits & 1) {
1506 HeNEXT(entry)= HeNEXT(aep[j]);
1507 HeNEXT(aep[j])= entry;
1509 /* Note, this is structured in such a way as the optimizer
1510 * should eliminate the duplicated code here and below without
1511 * us needing to explicitly use a goto. */
1512 HeNEXT(entry) = aep[j];
1518 /* see comment above about duplicated code */
1519 HeNEXT(entry) = aep[j];
1524 oentry = &HeNEXT(entry);
1528 } while (i++ < oldsize);
1532 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1534 XPVHV* xhv = (XPVHV*)SvANY(hv);
1535 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 */
1541 PERL_ARGS_ASSERT_HV_KSPLIT;
1543 wantsize = (I32) newmax; /* possible truncation here */
1544 if (wantsize != newmax)
1547 wantsize= wantsize + (wantsize >> 1); /* wantsize *= 1.5 */
1548 if (wantsize < newmax) /* overflow detection */
1552 while (wantsize > newsize) {
1553 trysize = newsize << 1;
1554 if (trysize > newsize) {
1562 if (newsize <= oldsize)
1563 return; /* overflow detection */
1565 a = (char *) HvARRAY(hv);
1567 hsplit(hv, oldsize, newsize);
1569 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1570 xhv->xhv_max = newsize - 1;
1571 HvARRAY(hv) = (HE **) a;
1575 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1576 * as tied hashes could play silly buggers and mess us around. We will
1577 * do the right thing during hv_store() afterwards, but still - Yves */
1578 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1579 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1580 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1581 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1583 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1584 hv_max = hv_max / 2; \
1586 HvMAX(hv) = hv_max; \
1591 Perl_newHVhv(pTHX_ HV *ohv)
1594 HV * const hv = newHV();
1597 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1599 hv_max = HvMAX(ohv);
1601 if (!SvMAGICAL((const SV *)ohv)) {
1602 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1604 const bool shared = !!HvSHAREKEYS(ohv);
1605 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1607 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1610 /* In each bucket... */
1611 for (i = 0; i <= hv_max; i++) {
1613 HE *oent = oents[i];
1620 /* Copy the linked list of entries. */
1621 for (; oent; oent = HeNEXT(oent)) {
1622 const U32 hash = HeHASH(oent);
1623 const char * const key = HeKEY(oent);
1624 const STRLEN len = HeKLEN(oent);
1625 const int flags = HeKFLAGS(oent);
1626 HE * const ent = new_HE();
1627 SV *const val = HeVAL(oent);
1629 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1631 = shared ? share_hek_flags(key, len, hash, flags)
1632 : save_hek_flags(key, len, hash, flags);
1643 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1647 /* Iterate over ohv, copying keys and values one at a time. */
1649 const I32 riter = HvRITER_get(ohv);
1650 HE * const eiter = HvEITER_get(ohv);
1651 STRLEN hv_keys = HvTOTALKEYS(ohv);
1653 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1656 while ((entry = hv_iternext_flags(ohv, 0))) {
1657 SV *val = hv_iterval(ohv,entry);
1658 SV * const keysv = HeSVKEY(entry);
1659 val = SvIMMORTAL(val) ? val : newSVsv(val);
1661 (void)hv_store_ent(hv, keysv, val, 0);
1663 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1664 HeHASH(entry), HeKFLAGS(entry));
1666 HvRITER_set(ohv, riter);
1667 HvEITER_set(ohv, eiter);
1674 =for apidoc hv_copy_hints_hv
1676 A specialised version of L</newHVhv> for copying C<%^H>. C<ohv> must be
1677 a pointer to a hash (which may have C<%^H> magic, but should be generally
1678 non-magical), or C<NULL> (interpreted as an empty hash). The content
1679 of C<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1680 added to it. A pointer to the new hash is returned.
1686 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1688 HV * const hv = newHV();
1691 STRLEN hv_max = HvMAX(ohv);
1692 STRLEN hv_keys = HvTOTALKEYS(ohv);
1694 const I32 riter = HvRITER_get(ohv);
1695 HE * const eiter = HvEITER_get(ohv);
1700 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1703 while ((entry = hv_iternext_flags(ohv, 0))) {
1704 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1705 SV *heksv = HeSVKEY(entry);
1706 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1707 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1708 (char *)heksv, HEf_SVKEY);
1709 if (heksv == HeSVKEY(entry))
1710 (void)hv_store_ent(hv, heksv, sv, 0);
1712 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1713 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1714 SvREFCNT_dec_NN(heksv);
1717 HvRITER_set(ohv, riter);
1718 HvEITER_set(ohv, eiter);
1720 SvREFCNT_inc_simple_void_NN(hv);
1723 hv_magic(hv, NULL, PERL_MAGIC_hints);
1726 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1728 /* like hv_free_ent, but returns the SV rather than freeing it */
1730 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1734 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1737 if (HeKLEN(entry) == HEf_SVKEY) {
1738 SvREFCNT_dec(HeKEY_sv(entry));
1739 Safefree(HeKEY_hek(entry));
1741 else if (HvSHAREKEYS(hv))
1742 unshare_hek(HeKEY_hek(entry));
1744 Safefree(HeKEY_hek(entry));
1751 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1755 PERL_ARGS_ASSERT_HV_FREE_ENT;
1759 val = hv_free_ent_ret(hv, entry);
1765 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1767 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1771 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1772 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1773 if (HeKLEN(entry) == HEf_SVKEY) {
1774 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1776 hv_free_ent(hv, entry);
1780 =for apidoc hv_clear
1782 Frees the all the elements of a hash, leaving it empty.
1783 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1785 See L</av_clear> for a note about the hash possibly being invalid on
1792 Perl_hv_clear(pTHX_ HV *hv)
1801 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1803 xhv = (XPVHV*)SvANY(hv);
1805 /* avoid hv being freed when calling destructors below */
1807 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
1808 orig_ix = PL_tmps_ix;
1809 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1810 /* restricted hash: convert all keys to placeholders */
1812 for (i = 0; i <= xhv->xhv_max; i++) {
1813 HE *entry = (HvARRAY(hv))[i];
1814 for (; entry; entry = HeNEXT(entry)) {
1815 /* not already placeholder */
1816 if (HeVAL(entry) != &PL_sv_placeholder) {
1818 if (SvREADONLY(HeVAL(entry))) {
1819 SV* const keysv = hv_iterkeysv(entry);
1820 Perl_croak_nocontext(
1821 "Attempt to delete readonly key '%" SVf "' from a restricted hash",
1824 SvREFCNT_dec_NN(HeVAL(entry));
1826 HeVAL(entry) = &PL_sv_placeholder;
1827 HvPLACEHOLDERS(hv)++;
1833 hv_free_entries(hv);
1834 HvPLACEHOLDERS_set(hv, 0);
1837 mg_clear(MUTABLE_SV(hv));
1839 HvHASKFLAGS_off(hv);
1843 mro_isa_changed_in(hv);
1844 HvEITER_set(hv, NULL);
1846 /* disarm hv's premature free guard */
1847 if (LIKELY(PL_tmps_ix == orig_ix))
1850 PL_tmps_stack[orig_ix] = &PL_sv_undef;
1851 SvREFCNT_dec_NN(hv);
1855 =for apidoc hv_clear_placeholders
1857 Clears any placeholders from a hash. If a restricted hash has any of its keys
1858 marked as readonly and the key is subsequently deleted, the key is not actually
1859 deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags
1860 it so it will be ignored by future operations such as iterating over the hash,
1861 but will still allow the hash to have a value reassigned to the key at some
1862 future point. This function clears any such placeholder keys from the hash.
1863 See C<L<Hash::Util::lock_keys()|Hash::Util/lock_keys>> for an example of its
1870 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1872 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1874 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1877 clear_placeholders(hv, items);
1881 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1886 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1893 /* Loop down the linked list heads */
1894 HE **oentry = &(HvARRAY(hv))[i];
1897 while ((entry = *oentry)) {
1898 if (HeVAL(entry) == &PL_sv_placeholder) {
1899 *oentry = HeNEXT(entry);
1900 if (entry == HvEITER_get(hv))
1903 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1904 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1905 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1906 hv_free_ent(hv, entry);
1911 I32 placeholders = HvPLACEHOLDERS_get(hv);
1912 HvTOTALKEYS(hv) -= (IV)placeholders;
1913 /* HvUSEDKEYS expanded */
1914 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1915 HvHASKFLAGS_off(hv);
1916 HvPLACEHOLDERS_set(hv, 0);
1920 oentry = &HeNEXT(entry);
1924 /* You can't get here, hence assertion should always fail. */
1925 assert (items == 0);
1926 NOT_REACHED; /* NOTREACHED */
1930 S_hv_free_entries(pTHX_ HV *hv)
1933 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1936 PERL_ARGS_ASSERT_HV_FREE_ENTRIES;
1938 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1944 /* hfree_next_entry()
1945 * For use only by S_hv_free_entries() and sv_clear().
1946 * Delete the next available HE from hv and return the associated SV.
1947 * Returns null on empty hash. Nevertheless null is not a reliable
1948 * indicator that the hash is empty, as the deleted entry may have a
1950 * indexp is a pointer to the current index into HvARRAY. The index should
1951 * initially be set to 0. hfree_next_entry() may update it. */
1954 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1956 struct xpvhv_aux *iter;
1960 STRLEN orig_index = *indexp;
1963 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1965 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1966 if ((entry = iter->xhv_eiter)) {
1967 /* the iterator may get resurrected after each
1968 * destructor call, so check each time */
1969 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1971 hv_free_ent(hv, entry);
1972 /* warning: at this point HvARRAY may have been
1973 * re-allocated, HvMAX changed etc */
1975 iter = HvAUX(hv); /* may have been realloced */
1976 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1977 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1978 #ifdef PERL_HASH_RANDOMIZE_KEYS
1979 iter->xhv_last_rand = iter->xhv_rand;
1984 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1987 array = HvARRAY(hv);
1989 while ( ! ((entry = array[*indexp])) ) {
1990 if ((*indexp)++ >= HvMAX(hv))
1992 assert(*indexp != orig_index);
1994 array[*indexp] = HeNEXT(entry);
1995 ((XPVHV*) SvANY(hv))->xhv_keys--;
1997 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1998 && HeVAL(entry) && isGV(HeVAL(entry))
1999 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
2002 const char * const key = HePV(entry,klen);
2003 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
2004 || (klen == 1 && key[0] == ':')) {
2006 NULL, GvHV(HeVAL(entry)),
2007 (GV *)HeVAL(entry), 0
2011 return hv_free_ent_ret(hv, entry);
2016 =for apidoc hv_undef
2018 Undefines the hash. The XS equivalent of C<undef(%hash)>.
2020 As well as freeing all the elements of the hash (like C<hv_clear()>), this
2021 also frees any auxiliary data and storage associated with the hash.
2023 See L</av_clear> for a note about the hash possibly being invalid on
2030 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
2034 SSize_t orig_ix = PL_tmps_ix; /* silence compiler warning about unitialized vars */
2038 save = cBOOL(SvREFCNT(hv));
2039 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2040 xhv = (XPVHV*)SvANY(hv);
2042 /* The name must be deleted before the call to hv_free_entries so that
2043 CVs are anonymised properly. But the effective name must be pre-
2044 served until after that call (and only deleted afterwards if the
2045 call originated from sv_clear). For stashes with one name that is
2046 both the canonical name and the effective name, hv_name_set has to
2047 allocate an array for storing the effective name. We can skip that
2048 during global destruction, as it does not matter where the CVs point
2049 if they will be freed anyway. */
2050 /* note that the code following prior to hv_free_entries is duplicated
2051 * in sv_clear(), and changes here should be done there too */
2052 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
2053 if (PL_stashcache) {
2054 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
2055 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2056 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2058 hv_name_set(hv, NULL, 0, 0);
2061 /* avoid hv being freed when calling destructors below */
2063 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
2064 orig_ix = PL_tmps_ix;
2066 hv_free_entries(hv);
2068 struct mro_meta *meta;
2071 if (HvENAME_get(hv)) {
2072 if (PL_phase != PERL_PHASE_DESTRUCT)
2073 mro_isa_changed_in(hv);
2074 if (PL_stashcache) {
2075 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
2076 HEKf "'\n", HEKfARG(HvENAME_HEK(hv))));
2077 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
2081 /* If this call originated from sv_clear, then we must check for
2082 * effective names that need freeing, as well as the usual name. */
2084 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
2085 if (name && PL_stashcache) {
2086 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
2087 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2088 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2090 hv_name_set(hv, NULL, 0, flags);
2092 if((meta = HvAUX(hv)->xhv_mro_meta)) {
2093 if (meta->mro_linear_all) {
2094 SvREFCNT_dec_NN(meta->mro_linear_all);
2095 /* mro_linear_current is just acting as a shortcut pointer,
2099 /* Only the current MRO is stored, so this owns the data.
2101 SvREFCNT_dec(meta->mro_linear_current);
2102 SvREFCNT_dec(meta->mro_nextmethod);
2103 SvREFCNT_dec(meta->isa);
2104 SvREFCNT_dec(meta->super);
2106 HvAUX(hv)->xhv_mro_meta = NULL;
2108 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
2109 SvFLAGS(hv) &= ~SVf_OOK;
2112 Safefree(HvARRAY(hv));
2113 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
2116 /* if we're freeing the HV, the SvMAGIC field has been reused for
2117 * other purposes, and so there can't be any placeholder magic */
2119 HvPLACEHOLDERS_set(hv, 0);
2122 mg_clear(MUTABLE_SV(hv));
2125 /* disarm hv's premature free guard */
2126 if (LIKELY(PL_tmps_ix == orig_ix))
2129 PL_tmps_stack[orig_ix] = &PL_sv_undef;
2130 SvREFCNT_dec_NN(hv);
2137 Returns the number of hash buckets that happen to be in use.
2139 This function is wrapped by the macro C<HvFILL>.
2141 As of perl 5.25 this function is used only for debugging
2142 purposes, and the number of used hash buckets is not
2143 in any way cached, thus this function can be costly
2144 to execute as it must iterate over all the buckets in the
2151 Perl_hv_fill(pTHX_ HV *const hv)
2154 HE **ents = HvARRAY(hv);
2156 PERL_UNUSED_CONTEXT;
2157 PERL_ARGS_ASSERT_HV_FILL;
2159 /* No keys implies no buckets used.
2160 One key can only possibly mean one bucket used. */
2161 if (HvTOTALKEYS(hv) < 2)
2162 return HvTOTALKEYS(hv);
2165 /* I wonder why we count down here...
2166 * Is it some micro-optimisation?
2167 * I would have thought counting up was better.
2170 HE *const *const last = ents + HvMAX(hv);
2171 count = last + 1 - ents;
2176 } while (++ents <= last);
2181 /* hash a pointer to a U32 - Used in the hash traversal randomization
2182 * and bucket order randomization code
2184 * this code was derived from Sereal, which was derived from autobox.
2187 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2190 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2191 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2193 u = (~u) + (u << 18);
2201 * This is one of Bob Jenkins' hash functions for 32-bit integers
2202 * from: http://burtleburtle.net/bob/hash/integer.html
2204 u = (u + 0x7ed55d16) + (u << 12);
2205 u = (u ^ 0xc761c23c) ^ (u >> 19);
2206 u = (u + 0x165667b1) + (u << 5);
2207 u = (u + 0xd3a2646c) ^ (u << 9);
2208 u = (u + 0xfd7046c5) + (u << 3);
2209 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2214 static struct xpvhv_aux*
2215 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
2216 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
2217 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2218 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2219 #ifdef PERL_HASH_RANDOMIZE_KEYS
2220 iter->xhv_last_rand = iter->xhv_rand;
2222 iter->xhv_name_u.xhvnameu_name = 0;
2223 iter->xhv_name_count = 0;
2224 iter->xhv_backreferences = 0;
2225 iter->xhv_mro_meta = NULL;
2226 iter->xhv_aux_flags = 0;
2231 static struct xpvhv_aux*
2232 S_hv_auxinit(pTHX_ HV *hv) {
2233 struct xpvhv_aux *iter;
2236 PERL_ARGS_ASSERT_HV_AUXINIT;
2240 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2241 + sizeof(struct xpvhv_aux), char);
2243 array = (char *) HvARRAY(hv);
2244 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
2245 + sizeof(struct xpvhv_aux), char);
2247 HvARRAY(hv) = (HE**)array;
2250 #ifdef PERL_HASH_RANDOMIZE_KEYS
2251 if (PL_HASH_RAND_BITS_ENABLED) {
2252 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2253 if (PL_HASH_RAND_BITS_ENABLED == 1)
2254 PL_hash_rand_bits += ptr_hash((PTRV)array);
2255 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2257 iter->xhv_rand = (U32)PL_hash_rand_bits;
2263 return hv_auxinit_internal(iter);
2267 =for apidoc hv_iterinit
2269 Prepares a starting point to traverse a hash table. Returns the number of
2270 keys in the hash, including placeholders (i.e. the same as C<HvTOTALKEYS(hv)>).
2271 The return value is currently only meaningful for hashes without tie magic.
2273 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2274 hash buckets that happen to be in use. If you still need that esoteric
2275 value, you can get it through the macro C<HvFILL(hv)>.
2282 Perl_hv_iterinit(pTHX_ HV *hv)
2284 PERL_ARGS_ASSERT_HV_ITERINIT;
2287 struct xpvhv_aux * iter = HvAUX(hv);
2288 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2289 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2291 hv_free_ent(hv, entry);
2293 iter = HvAUX(hv); /* may have been reallocated */
2294 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2295 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2296 #ifdef PERL_HASH_RANDOMIZE_KEYS
2297 iter->xhv_last_rand = iter->xhv_rand;
2303 /* note this includes placeholders! */
2304 return HvTOTALKEYS(hv);
2308 Perl_hv_riter_p(pTHX_ HV *hv) {
2309 struct xpvhv_aux *iter;
2311 PERL_ARGS_ASSERT_HV_RITER_P;
2313 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2314 return &(iter->xhv_riter);
2318 Perl_hv_eiter_p(pTHX_ HV *hv) {
2319 struct xpvhv_aux *iter;
2321 PERL_ARGS_ASSERT_HV_EITER_P;
2323 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2324 return &(iter->xhv_eiter);
2328 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2329 struct xpvhv_aux *iter;
2331 PERL_ARGS_ASSERT_HV_RITER_SET;
2339 iter = hv_auxinit(hv);
2341 iter->xhv_riter = riter;
2345 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2346 struct xpvhv_aux *iter;
2348 PERL_ARGS_ASSERT_HV_RAND_SET;
2350 #ifdef PERL_HASH_RANDOMIZE_KEYS
2354 iter = hv_auxinit(hv);
2356 iter->xhv_rand = new_xhv_rand;
2358 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2363 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2364 struct xpvhv_aux *iter;
2366 PERL_ARGS_ASSERT_HV_EITER_SET;
2371 /* 0 is the default so don't go malloc()ing a new structure just to
2376 iter = hv_auxinit(hv);
2378 iter->xhv_eiter = eiter;
2382 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2385 struct xpvhv_aux *iter;
2389 PERL_ARGS_ASSERT_HV_NAME_SET;
2392 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2396 if (iter->xhv_name_u.xhvnameu_name) {
2397 if(iter->xhv_name_count) {
2398 if(flags & HV_NAME_SETALL) {
2399 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2400 HEK **hekp = name + (
2401 iter->xhv_name_count < 0
2402 ? -iter->xhv_name_count
2403 : iter->xhv_name_count
2405 while(hekp-- > name+1)
2406 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2407 /* The first elem may be null. */
2408 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2410 iter = HvAUX(hv); /* may been realloced */
2411 spot = &iter->xhv_name_u.xhvnameu_name;
2412 iter->xhv_name_count = 0;
2415 if(iter->xhv_name_count > 0) {
2416 /* shift some things over */
2418 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2420 spot = iter->xhv_name_u.xhvnameu_names;
2421 spot[iter->xhv_name_count] = spot[1];
2423 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2425 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2426 unshare_hek_or_pvn(*spot, 0, 0, 0);
2430 else if (flags & HV_NAME_SETALL) {
2431 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2432 iter = HvAUX(hv); /* may been realloced */
2433 spot = &iter->xhv_name_u.xhvnameu_name;
2436 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2437 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2438 iter->xhv_name_count = -2;
2439 spot = iter->xhv_name_u.xhvnameu_names;
2440 spot[1] = existing_name;
2443 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2448 iter = hv_auxinit(hv);
2449 spot = &iter->xhv_name_u.xhvnameu_name;
2451 PERL_HASH(hash, name, len);
2452 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2456 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2461 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2462 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2463 if (flags & SVf_UTF8)
2464 return (bytes_cmp_utf8(
2465 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2466 (const U8*)pv, pvlen) == 0);
2468 return (bytes_cmp_utf8(
2469 (const U8*)pv, pvlen,
2470 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2473 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2474 || memEQ(HEK_KEY(hek), pv, pvlen));
2478 =for apidoc hv_ename_add
2480 Adds a name to a stash's internal list of effective names. See
2481 C<L</hv_ename_delete>>.
2483 This is called when a stash is assigned to a new location in the symbol
2490 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2493 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2496 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2499 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2501 PERL_HASH(hash, name, len);
2503 if (aux->xhv_name_count) {
2504 I32 count = aux->xhv_name_count;
2505 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2506 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2507 while (hekp-- > xhv_name)
2511 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2512 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2513 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2515 if (hekp == xhv_name && count < 0)
2516 aux->xhv_name_count = -count;
2520 if (count < 0) aux->xhv_name_count--, count = -count;
2521 else aux->xhv_name_count++;
2522 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2523 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2526 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2529 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2530 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2531 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2534 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2535 aux->xhv_name_count = existing_name ? 2 : -2;
2536 *aux->xhv_name_u.xhvnameu_names = existing_name;
2537 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2542 =for apidoc hv_ename_delete
2544 Removes a name from a stash's internal list of effective names. If this is
2545 the name returned by C<HvENAME>, then another name in the list will take
2546 its place (C<HvENAME> will use it).
2548 This is called when a stash is deleted from the symbol table.
2554 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2556 struct xpvhv_aux *aux;
2558 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2561 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2563 if (!SvOOK(hv)) return;
2566 if (!aux->xhv_name_u.xhvnameu_name) return;
2568 if (aux->xhv_name_count) {
2569 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2570 I32 const count = aux->xhv_name_count;
2571 HEK **victim = namep + (count < 0 ? -count : count);
2572 while (victim-- > namep + 1)
2574 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2575 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2576 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2578 unshare_hek_or_pvn(*victim, 0, 0, 0);
2579 aux = HvAUX(hv); /* may been realloced */
2580 if (count < 0) ++aux->xhv_name_count;
2581 else --aux->xhv_name_count;
2583 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2585 ) { /* if there are none left */
2587 aux->xhv_name_u.xhvnameu_names = NULL;
2588 aux->xhv_name_count = 0;
2591 /* Move the last one back to fill the empty slot. It
2592 does not matter what order they are in. */
2593 *victim = *(namep + (count < 0 ? -count : count) - 1);
2598 count > 0 && ((HEK_UTF8(*namep) || (flags & SVf_UTF8))
2599 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2600 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2603 aux->xhv_name_count = -count;
2607 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2608 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2609 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2610 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2612 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2613 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2614 *aux->xhv_name_u.xhvnameu_names = namehek;
2615 aux->xhv_name_count = -1;
2620 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2621 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2622 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2624 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2625 return &(iter->xhv_backreferences);
2630 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2633 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2638 av = HvAUX(hv)->xhv_backreferences;
2641 HvAUX(hv)->xhv_backreferences = 0;
2642 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2643 if (SvTYPE(av) == SVt_PVAV)
2644 SvREFCNT_dec_NN(av);
2649 hv_iternext is implemented as a macro in hv.h
2651 =for apidoc hv_iternext
2653 Returns entries from a hash iterator. See C<L</hv_iterinit>>.
2655 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2656 iterator currently points to, without losing your place or invalidating your
2657 iterator. Note that in this case the current entry is deleted from the hash
2658 with your iterator holding the last reference to it. Your iterator is flagged
2659 to free the entry on the next call to C<hv_iternext>, so you must not discard
2660 your iterator immediately else the entry will leak - call C<hv_iternext> to
2661 trigger the resource deallocation.
2663 =for apidoc hv_iternext_flags
2665 Returns entries from a hash iterator. See C<L</hv_iterinit>> and
2667 The C<flags> value will normally be zero; if C<HV_ITERNEXT_WANTPLACEHOLDERS> is
2668 set the placeholders keys (for restricted hashes) will be returned in addition
2669 to normal keys. By default placeholders are automatically skipped over.
2670 Currently a placeholder is implemented with a value that is
2671 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2672 restricted hashes may change, and the implementation currently is
2673 insufficiently abstracted for any change to be tidy.
2679 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2686 struct xpvhv_aux *iter;
2688 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2690 xhv = (XPVHV*)SvANY(hv);
2693 /* Too many things (well, pp_each at least) merrily assume that you can
2694 call hv_iternext without calling hv_iterinit, so we'll have to deal
2700 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2701 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2702 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2703 SV * const key = sv_newmortal();
2705 sv_setsv(key, HeSVKEY_force(entry));
2706 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2707 HeSVKEY_set(entry, NULL);
2713 /* one HE per MAGICAL hash */
2714 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2715 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2717 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2719 HeKEY_hek(entry) = hek;
2720 HeKLEN(entry) = HEf_SVKEY;
2722 magic_nextpack(MUTABLE_SV(hv),mg,key);
2724 /* force key to stay around until next time */
2725 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2726 return entry; /* beware, hent_val is not set */
2728 SvREFCNT_dec(HeVAL(entry));
2729 Safefree(HeKEY_hek(entry));
2731 iter = HvAUX(hv); /* may been realloced */
2732 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2737 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2738 if (!entry && SvRMAGICAL((const SV *)hv)
2739 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2742 /* The prime_env_iter() on VMS just loaded up new hash values
2743 * so the iteration count needs to be reset back to the beginning
2747 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2752 /* hv_iterinit now ensures this. */
2753 assert (HvARRAY(hv));
2755 /* At start of hash, entry is NULL. */
2758 entry = HeNEXT(entry);
2759 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2761 * Skip past any placeholders -- don't want to include them in
2764 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2765 entry = HeNEXT(entry);
2770 #ifdef PERL_HASH_RANDOMIZE_KEYS
2771 if (iter->xhv_last_rand != iter->xhv_rand) {
2772 if (iter->xhv_riter != -1) {
2773 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2774 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2778 iter = HvAUX(hv); /* may been realloced */
2779 iter->xhv_last_rand = iter->xhv_rand;
2783 /* Skip the entire loop if the hash is empty. */
2784 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2785 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2787 /* OK. Come to the end of the current list. Grab the next one. */
2789 iter->xhv_riter++; /* HvRITER(hv)++ */
2790 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2791 /* There is no next one. End of the hash. */
2792 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2793 #ifdef PERL_HASH_RANDOMIZE_KEYS
2794 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2798 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2800 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2801 /* If we have an entry, but it's a placeholder, don't count it.
2803 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2804 entry = HeNEXT(entry);
2806 /* Will loop again if this linked list starts NULL
2807 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2808 or if we run through it and find only placeholders. */
2812 iter->xhv_riter = -1;
2813 #ifdef PERL_HASH_RANDOMIZE_KEYS
2814 iter->xhv_last_rand = iter->xhv_rand;
2818 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2820 hv_free_ent(hv, oldentry);
2823 iter = HvAUX(hv); /* may been realloced */
2824 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2829 =for apidoc hv_iterkey
2831 Returns the key from the current position of the hash iterator. See
2838 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2840 PERL_ARGS_ASSERT_HV_ITERKEY;
2842 if (HeKLEN(entry) == HEf_SVKEY) {
2844 char * const p = SvPV(HeKEY_sv(entry), len);
2849 *retlen = HeKLEN(entry);
2850 return HeKEY(entry);
2854 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2856 =for apidoc hv_iterkeysv
2858 Returns the key as an C<SV*> from the current position of the hash
2859 iterator. The return value will always be a mortal copy of the key. Also
2860 see C<L</hv_iterinit>>.
2866 Perl_hv_iterkeysv(pTHX_ HE *entry)
2868 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2870 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2874 =for apidoc hv_iterval
2876 Returns the value from the current position of the hash iterator. See
2883 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2885 PERL_ARGS_ASSERT_HV_ITERVAL;
2887 if (SvRMAGICAL(hv)) {
2888 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2889 SV* const sv = sv_newmortal();
2890 if (HeKLEN(entry) == HEf_SVKEY)
2891 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2893 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2897 return HeVAL(entry);
2901 =for apidoc hv_iternextsv
2903 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2910 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2912 HE * const he = hv_iternext_flags(hv, 0);
2914 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2918 *key = hv_iterkey(he, retlen);
2919 return hv_iterval(hv, he);
2926 =for apidoc hv_magic
2928 Adds magic to a hash. See C<L</sv_magic>>.
2933 /* possibly free a shared string if no one has access to it
2934 * len and hash must both be valid for str.
2937 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2939 unshare_hek_or_pvn (NULL, str, len, hash);
2944 Perl_unshare_hek(pTHX_ HEK *hek)
2947 unshare_hek_or_pvn(hek, NULL, 0, 0);
2950 /* possibly free a shared string if no one has access to it
2951 hek if non-NULL takes priority over the other 3, else str, len and hash
2952 are used. If so, len and hash must both be valid for str.
2955 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2960 bool is_utf8 = FALSE;
2962 const char * const save = str;
2963 struct shared_he *he = NULL;
2966 /* Find the shared he which is just before us in memory. */
2967 he = (struct shared_he *)(((char *)hek)
2968 - STRUCT_OFFSET(struct shared_he,
2971 /* Assert that the caller passed us a genuine (or at least consistent)
2973 assert (he->shared_he_he.hent_hek == hek);
2975 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2976 --he->shared_he_he.he_valu.hent_refcount;
2980 hash = HEK_HASH(hek);
2981 } else if (len < 0) {
2982 STRLEN tmplen = -len;
2984 /* See the note in hv_fetch(). --jhi */
2985 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2988 k_flags = HVhek_UTF8;
2990 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2993 /* what follows was the moral equivalent of:
2994 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2996 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2998 xhv = (XPVHV*)SvANY(PL_strtab);
2999 /* assert(xhv_array != 0) */
3000 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
3002 const HE *const he_he = &(he->shared_he_he);
3003 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3008 const int flags_masked = k_flags & HVhek_MASK;
3009 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3010 if (HeHASH(entry) != hash) /* strings can't be equal */
3012 if (HeKLEN(entry) != len)
3014 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3016 if (HeKFLAGS(entry) != flags_masked)
3023 if (--entry->he_valu.hent_refcount == 0) {
3024 *oentry = HeNEXT(entry);
3026 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
3031 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
3032 "Attempt to free nonexistent shared string '%s'%s"
3034 hek ? HEK_KEY(hek) : str,
3035 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
3036 if (k_flags & HVhek_FREEKEY)
3040 /* get a (constant) string ptr from the global string table
3041 * string will get added if it is not already there.
3042 * len and hash must both be valid for str.
3045 Perl_share_hek(pTHX_ const char *str, SSize_t len, U32 hash)
3047 bool is_utf8 = FALSE;
3049 const char * const save = str;
3051 PERL_ARGS_ASSERT_SHARE_HEK;
3054 STRLEN tmplen = -len;
3056 /* See the note in hv_fetch(). --jhi */
3057 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
3059 /* If we were able to downgrade here, then than means that we were passed
3060 in a key which only had chars 0-255, but was utf8 encoded. */
3063 /* If we found we were able to downgrade the string to bytes, then
3064 we should flag that it needs upgrading on keys or each. Also flag
3065 that we need share_hek_flags to free the string. */
3068 PERL_HASH(hash, str, len);
3069 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
3073 return share_hek_flags (str, len, hash, flags);
3077 S_share_hek_flags(pTHX_ const char *str, STRLEN len, U32 hash, int flags)
3080 const int flags_masked = flags & HVhek_MASK;
3081 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
3082 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
3084 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
3086 if (UNLIKELY(len > (STRLEN) I32_MAX)) {
3087 Perl_croak_nocontext("Sorry, hash keys must be smaller than 2**31 bytes");
3090 /* what follows is the moral equivalent of:
3092 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
3093 hv_store(PL_strtab, str, len, NULL, hash);
3095 Can't rehash the shared string table, so not sure if it's worth
3096 counting the number of entries in the linked list
3099 /* assert(xhv_array != 0) */
3100 entry = (HvARRAY(PL_strtab))[hindex];
3101 for (;entry; entry = HeNEXT(entry)) {
3102 if (HeHASH(entry) != hash) /* strings can't be equal */
3104 if (HeKLEN(entry) != (SSize_t) len)
3106 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3108 if (HeKFLAGS(entry) != flags_masked)
3114 /* What used to be head of the list.
3115 If this is NULL, then we're the first entry for this slot, which
3116 means we need to increate fill. */
3117 struct shared_he *new_entry;
3120 HE **const head = &HvARRAY(PL_strtab)[hindex];
3121 HE *const next = *head;
3123 /* We don't actually store a HE from the arena and a regular HEK.
3124 Instead we allocate one chunk of memory big enough for both,
3125 and put the HEK straight after the HE. This way we can find the
3126 HE directly from the HEK.
3129 Newx(k, STRUCT_OFFSET(struct shared_he,
3130 shared_he_hek.hek_key[0]) + len + 2, char);
3131 new_entry = (struct shared_he *)k;
3132 entry = &(new_entry->shared_he_he);
3133 hek = &(new_entry->shared_he_hek);
3135 Copy(str, HEK_KEY(hek), len, char);
3136 HEK_KEY(hek)[len] = 0;
3138 HEK_HASH(hek) = hash;
3139 HEK_FLAGS(hek) = (unsigned char)flags_masked;
3141 /* Still "point" to the HEK, so that other code need not know what
3143 HeKEY_hek(entry) = hek;
3144 entry->he_valu.hent_refcount = 0;
3145 HeNEXT(entry) = next;
3148 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
3149 if (!next) { /* initial entry? */
3150 } else if ( DO_HSPLIT(xhv) ) {
3151 const STRLEN oldsize = xhv->xhv_max + 1;
3152 hsplit(PL_strtab, oldsize, oldsize * 2);
3156 ++entry->he_valu.hent_refcount;
3158 if (flags & HVhek_FREEKEY)
3161 return HeKEY_hek(entry);
3165 Perl_hv_placeholders_p(pTHX_ HV *hv)
3167 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3169 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
3172 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
3175 Perl_die(aTHX_ "panic: hv_placeholders_p");
3178 return &(mg->mg_len);
3183 Perl_hv_placeholders_get(pTHX_ const HV *hv)
3185 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3187 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
3188 PERL_UNUSED_CONTEXT;
3190 return mg ? mg->mg_len : 0;
3194 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3196 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3198 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3203 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3204 Perl_die(aTHX_ "panic: hv_placeholders_set");
3206 /* else we don't need to add magic to record 0 placeholders. */
3210 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3215 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3217 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3222 value = &PL_sv_placeholder;
3225 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3228 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3231 case HVrhek_PV_UTF8:
3232 /* Create a string SV that directly points to the bytes in our
3234 value = newSV_type(SVt_PV);
3235 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3236 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3237 /* This stops anything trying to free it */
3238 SvLEN_set(value, 0);
3240 SvREADONLY_on(value);
3241 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3245 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %" UVxf,
3246 (UV)he->refcounted_he_data[0]);
3252 =for apidoc refcounted_he_chain_2hv
3254 Generates and returns a C<HV *> representing the content of a
3255 C<refcounted_he> chain.
3256 C<flags> is currently unused and must be zero.
3261 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3265 U32 placeholders, max;
3268 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %" UVxf,
3271 /* We could chase the chain once to get an idea of the number of keys,
3272 and call ksplit. But for now we'll make a potentially inefficient
3273 hash with only 8 entries in its array. */
3278 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3279 HvARRAY(hv) = (HE**)array;
3285 U32 hash = chain->refcounted_he_hash;
3287 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3289 HE **oentry = &((HvARRAY(hv))[hash & max]);
3290 HE *entry = *oentry;
3293 for (; entry; entry = HeNEXT(entry)) {
3294 if (HeHASH(entry) == hash) {
3295 /* We might have a duplicate key here. If so, entry is older
3296 than the key we've already put in the hash, so if they are
3297 the same, skip adding entry. */
3299 const STRLEN klen = HeKLEN(entry);
3300 const char *const key = HeKEY(entry);
3301 if (klen == chain->refcounted_he_keylen
3302 && (!!HeKUTF8(entry)
3303 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3304 && memEQ(key, REF_HE_KEY(chain), klen))
3307 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3309 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3310 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3311 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3322 = share_hek_flags(REF_HE_KEY(chain),
3323 chain->refcounted_he_keylen,
3324 chain->refcounted_he_hash,
3325 (chain->refcounted_he_data[0]
3326 & (HVhek_UTF8|HVhek_WASUTF8)));
3328 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3330 value = refcounted_he_value(chain);
3331 if (value == &PL_sv_placeholder)
3333 HeVAL(entry) = value;
3335 /* Link it into the chain. */
3336 HeNEXT(entry) = *oentry;
3342 chain = chain->refcounted_he_next;
3346 clear_placeholders(hv, placeholders);
3347 HvTOTALKEYS(hv) -= placeholders;
3350 /* We could check in the loop to see if we encounter any keys with key
3351 flags, but it's probably not worth it, as this per-hash flag is only
3352 really meant as an optimisation for things like Storable. */
3354 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3360 =for apidoc refcounted_he_fetch_pvn
3362 Search along a C<refcounted_he> chain for an entry with the key specified
3363 by C<keypv> and C<keylen>. If C<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3364 bit set, the key octets are interpreted as UTF-8, otherwise they
3365 are interpreted as Latin-1. C<hash> is a precomputed hash of the key
3366 string, or zero if it has not been precomputed. Returns a mortal scalar
3367 representing the value associated with the key, or C<&PL_sv_placeholder>
3368 if there is no value associated with the key.
3374 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3375 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3379 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3381 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3382 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %" UVxf,
3386 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3387 /* For searching purposes, canonicalise to Latin-1 where possible. */
3388 const char *keyend = keypv + keylen, *p;
3389 STRLEN nonascii_count = 0;
3390 for (p = keypv; p != keyend; p++) {
3391 if (! UTF8_IS_INVARIANT(*p)) {
3392 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3393 goto canonicalised_key;
3399 if (nonascii_count) {
3401 const char *p = keypv, *keyend = keypv + keylen;
3402 keylen -= nonascii_count;
3403 Newx(q, keylen, char);
3406 for (; p != keyend; p++, q++) {
3408 if (UTF8_IS_INVARIANT(c)) {
3413 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3417 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3418 canonicalised_key: ;
3420 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3422 PERL_HASH(hash, keypv, keylen);
3424 for (; chain; chain = chain->refcounted_he_next) {
3427 hash == chain->refcounted_he_hash &&
3428 keylen == chain->refcounted_he_keylen &&
3429 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3430 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3432 hash == HEK_HASH(chain->refcounted_he_hek) &&
3433 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3434 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3435 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3438 if (flags & REFCOUNTED_HE_EXISTS)
3439 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3441 ? NULL : &PL_sv_yes;
3442 return sv_2mortal(refcounted_he_value(chain));
3446 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3450 =for apidoc refcounted_he_fetch_pv
3452 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3453 instead of a string/length pair.
3459 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3460 const char *key, U32 hash, U32 flags)
3462 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3463 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3467 =for apidoc refcounted_he_fetch_sv
3469 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3476 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3477 SV *key, U32 hash, U32 flags)
3481 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3482 if (flags & REFCOUNTED_HE_KEY_UTF8)
3483 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %" UVxf,
3485 keypv = SvPV_const(key, keylen);
3487 flags |= REFCOUNTED_HE_KEY_UTF8;
3488 if (!hash && SvIsCOW_shared_hash(key))
3489 hash = SvSHARED_HASH(key);
3490 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3494 =for apidoc refcounted_he_new_pvn
3496 Creates a new C<refcounted_he>. This consists of a single key/value
3497 pair and a reference to an existing C<refcounted_he> chain (which may
3498 be empty), and thus forms a longer chain. When using the longer chain,
3499 the new key/value pair takes precedence over any entry for the same key
3500 further along the chain.
3502 The new key is specified by C<keypv> and C<keylen>. If C<flags> has
3503 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3504 as UTF-8, otherwise they are interpreted as Latin-1. C<hash> is
3505 a precomputed hash of the key string, or zero if it has not been
3508 C<value> is the scalar value to store for this key. C<value> is copied
3509 by this function, which thus does not take ownership of any reference
3510 to it, and later changes to the scalar will not be reflected in the
3511 value visible in the C<refcounted_he>. Complex types of scalar will not
3512 be stored with referential integrity, but will be coerced to strings.
3513 C<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3514 value is to be associated with the key; this, as with any non-null value,
3515 takes precedence over the existence of a value for the key further along
3518 C<parent> points to the rest of the C<refcounted_he> chain to be
3519 attached to the new C<refcounted_he>. This function takes ownership
3520 of one reference to C<parent>, and returns one reference to the new
3526 struct refcounted_he *
3527 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3528 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3531 STRLEN value_len = 0;
3532 const char *value_p = NULL;
3536 STRLEN key_offset = 1;
3537 struct refcounted_he *he;
3538 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3540 if (!value || value == &PL_sv_placeholder) {
3541 value_type = HVrhek_delete;
3542 } else if (SvPOK(value)) {
3543 value_type = HVrhek_PV;
3544 } else if (SvIOK(value)) {
3545 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3546 } else if (!SvOK(value)) {
3547 value_type = HVrhek_undef;
3549 value_type = HVrhek_PV;
3551 is_pv = value_type == HVrhek_PV;
3553 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3554 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3555 value_p = SvPV_const(value, value_len);
3557 value_type = HVrhek_PV_UTF8;
3558 key_offset = value_len + 2;
3560 hekflags = value_type;
3562 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3563 /* Canonicalise to Latin-1 where possible. */
3564 const char *keyend = keypv + keylen, *p;
3565 STRLEN nonascii_count = 0;
3566 for (p = keypv; p != keyend; p++) {
3567 if (! UTF8_IS_INVARIANT(*p)) {
3568 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3569 goto canonicalised_key;
3575 if (nonascii_count) {
3577 const char *p = keypv, *keyend = keypv + keylen;
3578 keylen -= nonascii_count;
3579 Newx(q, keylen, char);
3582 for (; p != keyend; p++, q++) {
3584 if (UTF8_IS_INVARIANT(c)) {
3589 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3593 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3594 canonicalised_key: ;
3596 if (flags & REFCOUNTED_HE_KEY_UTF8)
3597 hekflags |= HVhek_UTF8;
3599 PERL_HASH(hash, keypv, keylen);
3602 he = (struct refcounted_he*)
3603 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3607 he = (struct refcounted_he*)
3608 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3612 he->refcounted_he_next = parent;
3615 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3616 he->refcounted_he_val.refcounted_he_u_len = value_len;
3617 } else if (value_type == HVrhek_IV) {
3618 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3619 } else if (value_type == HVrhek_UV) {
3620 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3624 he->refcounted_he_hash = hash;
3625 he->refcounted_he_keylen = keylen;
3626 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3628 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3631 he->refcounted_he_data[0] = hekflags;
3632 he->refcounted_he_refcnt = 1;
3638 =for apidoc refcounted_he_new_pv
3640 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3641 of a string/length pair.
3646 struct refcounted_he *
3647 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3648 const char *key, U32 hash, SV *value, U32 flags)
3650 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3651 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3655 =for apidoc refcounted_he_new_sv
3657 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3663 struct refcounted_he *
3664 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3665 SV *key, U32 hash, SV *value, U32 flags)
3669 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3670 if (flags & REFCOUNTED_HE_KEY_UTF8)
3671 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %" UVxf,
3673 keypv = SvPV_const(key, keylen);
3675 flags |= REFCOUNTED_HE_KEY_UTF8;
3676 if (!hash && SvIsCOW_shared_hash(key))
3677 hash = SvSHARED_HASH(key);
3678 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3682 =for apidoc refcounted_he_free
3684 Decrements the reference count of a C<refcounted_he> by one. If the
3685 reference count reaches zero the structure's memory is freed, which
3686 (recursively) causes a reduction of its parent C<refcounted_he>'s
3687 reference count. It is safe to pass a null pointer to this function:
3688 no action occurs in this case.
3694 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3698 PERL_UNUSED_CONTEXT;
3701 struct refcounted_he *copy;
3705 new_count = --he->refcounted_he_refcnt;
3706 HINTS_REFCNT_UNLOCK;
3712 #ifndef USE_ITHREADS
3713 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3716 he = he->refcounted_he_next;
3717 PerlMemShared_free(copy);
3722 =for apidoc refcounted_he_inc
3724 Increment the reference count of a C<refcounted_he>. The pointer to the
3725 C<refcounted_he> is also returned. It is safe to pass a null pointer
3726 to this function: no action occurs and a null pointer is returned.
3731 struct refcounted_he *
3732 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3737 PERL_UNUSED_CONTEXT;
3740 he->refcounted_he_refcnt++;
3741 HINTS_REFCNT_UNLOCK;
3747 =for apidoc cop_fetch_label
3749 Returns the label attached to a cop.
3750 The flags pointer may be set to C<SVf_UTF8> or 0.
3755 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3758 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3759 struct refcounted_he *const chain = cop->cop_hints_hash;
3761 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3762 PERL_UNUSED_CONTEXT;
3767 if (chain->refcounted_he_keylen != 1)
3769 if (*REF_HE_KEY(chain) != ':')
3772 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3774 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3777 /* Stop anyone trying to really mess us up by adding their own value for
3779 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3780 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3784 *len = chain->refcounted_he_val.refcounted_he_u_len;
3786 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3787 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3789 return chain->refcounted_he_data + 1;
3793 =for apidoc cop_store_label
3795 Save a label into a C<cop_hints_hash>.
3796 You need to set flags to C<SVf_UTF8>
3803 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3807 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3809 if (flags & ~(SVf_UTF8))
3810 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3812 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3813 if (flags & SVf_UTF8)
3816 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3820 =for apidoc hv_assert
3822 Check that a hash is in an internally consistent state.
3830 Perl_hv_assert(pTHX_ HV *hv)
3835 int placeholders = 0;
3838 const I32 riter = HvRITER_get(hv);
3839 HE *eiter = HvEITER_get(hv);
3841 PERL_ARGS_ASSERT_HV_ASSERT;
3843 (void)hv_iterinit(hv);
3845 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3846 /* sanity check the values */
3847 if (HeVAL(entry) == &PL_sv_placeholder)
3851 /* sanity check the keys */
3852 if (HeSVKEY(entry)) {
3853 NOOP; /* Don't know what to check on SV keys. */
3854 } else if (HeKUTF8(entry)) {
3856 if (HeKWASUTF8(entry)) {
3857 PerlIO_printf(Perl_debug_log,
3858 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3859 (int) HeKLEN(entry), HeKEY(entry));
3862 } else if (HeKWASUTF8(entry))
3865 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3866 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3867 const int nhashkeys = HvUSEDKEYS(hv);
3868 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3870 if (nhashkeys != real) {
3871 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3874 if (nhashplaceholders != placeholders) {
3875 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3879 if (withflags && ! HvHASKFLAGS(hv)) {
3880 PerlIO_printf(Perl_debug_log,
3881 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3886 sv_dump(MUTABLE_SV(hv));
3888 HvRITER_set(hv, riter); /* Restore hash iterator state */
3889 HvEITER_set(hv, eiter);
3895 * ex: set ts=8 sts=4 sw=4 et: