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"]
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()
42 /* MAX_BUCKET_MAX is the maximum max bucket index, at which point we stop growing the
45 #define MAX_BUCKET_MAX ((1<<26)-1)
46 #define DO_HSPLIT(xhv) ( ( ((xhv)->xhv_keys + ((xhv)->xhv_keys >> 1)) > (xhv)->xhv_max ) && \
47 ((xhv)->xhv_max < MAX_BUCKET_MAX) )
49 static const char S_strtab_error[]
50 = "Cannot modify shared string table in hv_%s";
54 #define new_HE() (HE*)safemalloc(sizeof(HE))
55 #define del_HE(p) safefree((char*)p)
63 void ** const root = &PL_body_roots[HE_SVSLOT];
66 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
73 #define new_HE() new_he()
76 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
77 PL_body_roots[HE_SVSLOT] = p; \
85 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
87 const int flags_masked = flags & HVhek_MASK;
91 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
93 Newx(k, HEK_BASESIZE + len + 2, char);
95 Copy(str, HEK_KEY(hek), len, char);
96 HEK_KEY(hek)[len] = 0;
99 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
101 if (flags & HVhek_FREEKEY)
106 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
110 Perl_free_tied_hv_pool(pTHX)
112 HE *he = PL_hv_fetch_ent_mh;
115 Safefree(HeKEY_hek(he));
119 PL_hv_fetch_ent_mh = NULL;
122 #if defined(USE_ITHREADS)
124 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
128 PERL_ARGS_ASSERT_HEK_DUP;
129 PERL_UNUSED_ARG(param);
134 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
136 /* We already shared this hash key. */
137 (void)share_hek_hek(shared);
141 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
142 HEK_HASH(source), HEK_FLAGS(source));
143 ptr_table_store(PL_ptr_table, source, shared);
149 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
153 PERL_ARGS_ASSERT_HE_DUP;
157 /* look for it in the table first */
158 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
162 /* create anew and remember what it is */
164 ptr_table_store(PL_ptr_table, e, ret);
166 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
167 if (HeKLEN(e) == HEf_SVKEY) {
169 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
170 HeKEY_hek(ret) = (HEK*)k;
171 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
174 /* This is hek_dup inlined, which seems to be important for speed
176 HEK * const source = HeKEY_hek(e);
177 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
180 /* We already shared this hash key. */
181 (void)share_hek_hek(shared);
185 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
186 HEK_HASH(source), HEK_FLAGS(source));
187 ptr_table_store(PL_ptr_table, source, shared);
189 HeKEY_hek(ret) = shared;
192 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
194 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
197 #endif /* USE_ITHREADS */
200 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
203 SV * const sv = sv_newmortal();
205 PERL_ARGS_ASSERT_HV_NOTALLOWED;
207 if (!(flags & HVhek_FREEKEY)) {
208 sv_setpvn(sv, key, klen);
211 /* Need to free saved eventually assign to mortal SV */
212 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
213 sv_usepvn(sv, (char *) key, klen);
215 if (flags & HVhek_UTF8) {
218 Perl_croak(aTHX_ msg, SVfARG(sv));
221 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
227 Stores an SV in a hash. The hash key is specified as C<key> and the
228 absolute value of C<klen> is the length of the key. If C<klen> is
229 negative the key is assumed to be in UTF-8-encoded Unicode. The
230 C<hash> parameter is the precomputed hash value; if it is zero then
231 Perl will compute it.
233 The return value will be
234 C<NULL> if the operation failed or if the value did not need to be actually
235 stored within the hash (as in the case of tied hashes). Otherwise it can
236 be dereferenced to get the original C<SV*>. Note that the caller is
237 responsible for suitably incrementing the reference count of C<val> before
238 the call, and decrementing it if the function returned C<NULL>. Effectively
239 a successful C<hv_store> takes ownership of one reference to C<val>. This is
240 usually what you want; a newly created SV has a reference count of one, so
241 if all your code does is create SVs then store them in a hash, C<hv_store>
242 will own the only reference to the new SV, and your code doesn't need to do
243 anything further to tidy up. C<hv_store> is not implemented as a call to
244 C<hv_store_ent>, and does not create a temporary SV for the key, so if your
245 key data is not already in SV form then use C<hv_store> in preference to
248 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
249 information on how to use this function on tied hashes.
251 =for apidoc hv_store_ent
253 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
254 parameter is the precomputed hash value; if it is zero then Perl will
255 compute it. The return value is the new hash entry so created. It will be
256 C<NULL> if the operation failed or if the value did not need to be actually
257 stored within the hash (as in the case of tied hashes). Otherwise the
258 contents of the return value can be accessed using the C<He?> macros
259 described here. Note that the caller is responsible for suitably
260 incrementing the reference count of C<val> before the call, and
261 decrementing it if the function returned NULL. Effectively a successful
262 C<hv_store_ent> takes ownership of one reference to C<val>. This is
263 usually what you want; a newly created SV has a reference count of one, so
264 if all your code does is create SVs then store them in a hash, C<hv_store>
265 will own the only reference to the new SV, and your code doesn't need to do
266 anything further to tidy up. Note that C<hv_store_ent> only reads the C<key>;
267 unlike C<val> it does not take ownership of it, so maintaining the correct
268 reference count on C<key> is entirely the caller's responsibility. The reason
269 it does not take ownership, is that C<key> is not used after this function
270 returns, and so can be freed immediately. C<hv_store>
271 is not implemented as a call to C<hv_store_ent>, and does not create a temporary
272 SV for the key, so if your key data is not already in SV form then use
273 C<hv_store> in preference to C<hv_store_ent>.
275 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
276 information on how to use this function on tied hashes.
278 =for apidoc hv_exists
280 Returns a boolean indicating whether the specified hash key exists. The
281 absolute value of C<klen> is the length of the key. If C<klen> is
282 negative the key is assumed to be in UTF-8-encoded Unicode.
286 Returns the SV which corresponds to the specified key in the hash.
287 The absolute value of C<klen> is the length of the key. If C<klen> is
288 negative the key is assumed to be in UTF-8-encoded Unicode. If
289 C<lval> is set then the fetch will be part of a store. This means that if
290 there is no value in the hash associated with the given key, then one is
291 created and a pointer to it is returned. The C<SV*> it points to can be
292 assigned to. But always check that the
293 return value is non-null before dereferencing it to an C<SV*>.
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
298 =for apidoc hv_exists_ent
300 Returns a boolean indicating whether
301 the specified hash key exists. C<hash>
302 can be a valid precomputed hash value, or 0 to ask for it to be
308 /* returns an HE * structure with the all fields set */
309 /* note that hent_val will be a mortal sv for MAGICAL hashes */
311 =for apidoc hv_fetch_ent
313 Returns the hash entry which corresponds to the specified key in the hash.
314 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
315 if you want the function to compute it. IF C<lval> is set then the fetch
316 will be part of a store. Make sure the return value is non-null before
317 accessing it. The return value when C<hv> is a tied hash is a pointer to a
318 static location, so be sure to make a copy of the structure if you need to
321 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
322 information on how to use this function on tied hashes.
327 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
329 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
330 const int action, SV *val, const U32 hash)
335 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
344 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
348 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
349 int flags, int action, SV *val, U32 hash)
358 const int return_svp = action & HV_FETCH_JUST_SV;
359 HEK *keysv_hek = NULL;
363 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
366 assert(SvTYPE(hv) == SVt_PVHV);
368 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
370 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
371 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
372 if (uf->uf_set == NULL) {
373 SV* obj = mg->mg_obj;
376 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
377 ((flags & HVhek_UTF8)
381 mg->mg_obj = keysv; /* pass key */
382 uf->uf_index = action; /* pass action */
383 magic_getuvar(MUTABLE_SV(hv), mg);
384 keysv = mg->mg_obj; /* may have changed */
387 /* If the key may have changed, then we need to invalidate
388 any passed-in computed hash value. */
394 if (flags & HVhek_FREEKEY)
396 key = SvPV_const(keysv, klen);
397 is_utf8 = (SvUTF8(keysv) != 0);
398 if (SvIsCOW_shared_hash(keysv)) {
399 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
404 is_utf8 = cBOOL(flags & HVhek_UTF8);
407 if (action & HV_DELETE) {
408 return (void *) hv_delete_common(hv, keysv, key, klen,
409 flags | (is_utf8 ? HVhek_UTF8 : 0),
413 xhv = (XPVHV*)SvANY(hv);
415 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
416 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
417 || SvGMAGICAL((const SV *)hv))
419 /* FIXME should be able to skimp on the HE/HEK here when
420 HV_FETCH_JUST_SV is true. */
422 keysv = newSVpvn_utf8(key, klen, is_utf8);
424 keysv = newSVsv(keysv);
427 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
429 /* grab a fake HE/HEK pair from the pool or make a new one */
430 entry = PL_hv_fetch_ent_mh;
432 PL_hv_fetch_ent_mh = HeNEXT(entry);
436 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
437 HeKEY_hek(entry) = (HEK*)k;
439 HeNEXT(entry) = NULL;
440 HeSVKEY_set(entry, keysv);
442 sv_upgrade(sv, SVt_PVLV);
444 /* so we can free entry when freeing sv */
445 LvTARG(sv) = MUTABLE_SV(entry);
447 /* XXX remove at some point? */
448 if (flags & HVhek_FREEKEY)
452 return entry ? (void *) &HeVAL(entry) : NULL;
454 return (void *) entry;
456 #ifdef ENV_IS_CASELESS
457 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
459 for (i = 0; i < klen; ++i)
460 if (isLOWER(key[i])) {
461 /* Would be nice if we had a routine to do the
462 copy and upercase in a single pass through. */
463 const char * const nkey = strupr(savepvn(key,klen));
464 /* Note that this fetch is for nkey (the uppercased
465 key) whereas the store is for key (the original) */
466 void *result = hv_common(hv, NULL, nkey, klen,
467 HVhek_FREEKEY, /* free nkey */
468 0 /* non-LVAL fetch */
469 | HV_DISABLE_UVAR_XKEY
472 0 /* compute hash */);
473 if (!result && (action & HV_FETCH_LVALUE)) {
474 /* This call will free key if necessary.
475 Do it this way to encourage compiler to tail
477 result = hv_common(hv, keysv, key, klen, flags,
479 | HV_DISABLE_UVAR_XKEY
483 if (flags & HVhek_FREEKEY)
491 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
492 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
493 || SvGMAGICAL((const SV *)hv)) {
494 /* I don't understand why hv_exists_ent has svret and sv,
495 whereas hv_exists only had one. */
496 SV * const svret = sv_newmortal();
499 if (keysv || is_utf8) {
501 keysv = newSVpvn_utf8(key, klen, TRUE);
503 keysv = newSVsv(keysv);
505 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
507 mg_copy(MUTABLE_SV(hv), sv, key, klen);
509 if (flags & HVhek_FREEKEY)
512 MAGIC * const mg = mg_find(sv, PERL_MAGIC_tiedelem);
514 magic_existspack(svret, mg);
516 /* This cast somewhat evil, but I'm merely using NULL/
517 not NULL to return the boolean exists.
518 And I know hv is not NULL. */
519 return SvTRUE_NN(svret) ? (void *)hv : NULL;
521 #ifdef ENV_IS_CASELESS
522 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
523 /* XXX This code isn't UTF8 clean. */
524 char * const keysave = (char * const)key;
525 /* Will need to free this, so set FREEKEY flag. */
526 key = savepvn(key,klen);
527 key = (const char*)strupr((char*)key);
532 if (flags & HVhek_FREEKEY) {
535 flags |= HVhek_FREEKEY;
539 else if (action & HV_FETCH_ISSTORE) {
542 hv_magic_check (hv, &needs_copy, &needs_store);
544 const bool save_taint = TAINT_get;
545 if (keysv || is_utf8) {
547 keysv = newSVpvn_utf8(key, klen, TRUE);
550 TAINT_set(SvTAINTED(keysv));
551 keysv = sv_2mortal(newSVsv(keysv));
552 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
554 mg_copy(MUTABLE_SV(hv), val, key, klen);
557 TAINT_IF(save_taint);
558 #ifdef NO_TAINT_SUPPORT
559 PERL_UNUSED_VAR(save_taint);
562 if (flags & HVhek_FREEKEY)
566 #ifdef ENV_IS_CASELESS
567 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
568 /* XXX This code isn't UTF8 clean. */
569 const char *keysave = key;
570 /* Will need to free this, so set FREEKEY flag. */
571 key = savepvn(key,klen);
572 key = (const char*)strupr((char*)key);
577 if (flags & HVhek_FREEKEY) {
580 flags |= HVhek_FREEKEY;
588 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
589 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
590 || (SvRMAGICAL((const SV *)hv)
591 && mg_find((const SV *)hv, PERL_MAGIC_env))
596 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
598 HvARRAY(hv) = (HE**)array;
600 #ifdef DYNAMIC_ENV_FETCH
601 else if (action & HV_FETCH_ISEXISTS) {
602 /* for an %ENV exists, if we do an insert it's by a recursive
603 store call, so avoid creating HvARRAY(hv) right now. */
607 /* XXX remove at some point? */
608 if (flags & HVhek_FREEKEY)
615 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
616 char * const keysave = (char *)key;
617 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
621 flags &= ~HVhek_UTF8;
622 if (key != keysave) {
623 if (flags & HVhek_FREEKEY)
625 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
626 /* If the caller calculated a hash, it was on the sequence of
627 octets that are the UTF-8 form. We've now changed the sequence
628 of octets stored to that of the equivalent byte representation,
629 so the hash we need is different. */
634 if (keysv && (SvIsCOW_shared_hash(keysv))) {
636 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
637 hash = SvSHARED_HASH(keysv);
640 PERL_HASH(hash, key, klen);
642 masked_flags = (flags & HVhek_MASK);
644 #ifdef DYNAMIC_ENV_FETCH
645 if (!HvARRAY(hv)) entry = NULL;
649 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
656 /* keysv is actually a HEK in disguise, so we can match just by
657 * comparing the HEK pointers in the HE chain. There is a slight
658 * caveat: on something like "\x80", which has both plain and utf8
659 * representations, perl's hashes do encoding-insensitive lookups,
660 * but preserve the encoding of the stored key. Thus a particular
661 * key could map to two different HEKs in PL_strtab. We only
662 * conclude 'not found' if all the flags are the same; otherwise
663 * we fall back to a full search (this should only happen in rare
666 int keysv_flags = HEK_FLAGS(keysv_hek);
667 HE *orig_entry = entry;
669 for (; entry; entry = HeNEXT(entry)) {
670 HEK *hek = HeKEY_hek(entry);
671 if (hek == keysv_hek)
673 if (HEK_FLAGS(hek) != keysv_flags)
674 break; /* need to do full match */
678 /* failed on shortcut - do full search loop */
682 for (; entry; entry = HeNEXT(entry)) {
683 if (HeHASH(entry) != hash) /* strings can't be equal */
685 if (HeKLEN(entry) != (I32)klen)
687 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
689 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
693 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
694 if (HeKFLAGS(entry) != masked_flags) {
695 /* We match if HVhek_UTF8 bit in our flags and hash key's
696 match. But if entry was set previously with HVhek_WASUTF8
697 and key now doesn't (or vice versa) then we should change
698 the key's flag, as this is assignment. */
699 if (HvSHAREKEYS(hv)) {
700 /* Need to swap the key we have for a key with the flags we
701 need. As keys are shared we can't just write to the
702 flag, so we share the new one, unshare the old one. */
703 HEK * const new_hek = share_hek_flags(key, klen, hash,
705 unshare_hek (HeKEY_hek(entry));
706 HeKEY_hek(entry) = new_hek;
708 else if (hv == PL_strtab) {
709 /* PL_strtab is usually the only hash without HvSHAREKEYS,
710 so putting this test here is cheap */
711 if (flags & HVhek_FREEKEY)
713 Perl_croak(aTHX_ S_strtab_error,
714 action & HV_FETCH_LVALUE ? "fetch" : "store");
717 HeKFLAGS(entry) = masked_flags;
718 if (masked_flags & HVhek_ENABLEHVKFLAGS)
721 if (HeVAL(entry) == &PL_sv_placeholder) {
722 /* yes, can store into placeholder slot */
723 if (action & HV_FETCH_LVALUE) {
725 /* This preserves behaviour with the old hv_fetch
726 implementation which at this point would bail out
727 with a break; (at "if we find a placeholder, we
728 pretend we haven't found anything")
730 That break mean that if a placeholder were found, it
731 caused a call into hv_store, which in turn would
732 check magic, and if there is no magic end up pretty
733 much back at this point (in hv_store's code). */
736 /* LVAL fetch which actually needs a store. */
738 HvPLACEHOLDERS(hv)--;
741 if (val != &PL_sv_placeholder)
742 HvPLACEHOLDERS(hv)--;
745 } else if (action & HV_FETCH_ISSTORE) {
746 SvREFCNT_dec(HeVAL(entry));
749 } else if (HeVAL(entry) == &PL_sv_placeholder) {
750 /* if we find a placeholder, we pretend we haven't found
754 if (flags & HVhek_FREEKEY)
757 return (void *) &HeVAL(entry);
763 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
764 if (!(action & HV_FETCH_ISSTORE)
765 && SvRMAGICAL((const SV *)hv)
766 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
768 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
770 sv = newSVpvn(env,len);
772 return hv_common(hv, keysv, key, klen, flags,
773 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
779 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
780 hv_notallowed(flags, key, klen,
781 "Attempt to access disallowed key '%" SVf "' in"
782 " a restricted hash");
784 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
785 /* Not doing some form of store, so return failure. */
786 if (flags & HVhek_FREEKEY)
790 if (action & HV_FETCH_LVALUE) {
791 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
793 /* At this point the old hv_fetch code would call to hv_store,
794 which in turn might do some tied magic. So we need to make that
795 magic check happen. */
796 /* gonna assign to this, so it better be there */
797 /* If a fetch-as-store fails on the fetch, then the action is to
798 recurse once into "hv_store". If we didn't do this, then that
799 recursive call would call the key conversion routine again.
800 However, as we replace the original key with the converted
801 key, this would result in a double conversion, which would show
802 up as a bug if the conversion routine is not idempotent.
803 Hence the use of HV_DISABLE_UVAR_XKEY. */
804 return hv_common(hv, keysv, key, klen, flags,
805 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
807 /* XXX Surely that could leak if the fetch-was-store fails?
808 Just like the hv_fetch. */
812 /* Welcome to hv_store... */
815 /* Not sure if we can get here. I think the only case of oentry being
816 NULL is for %ENV with dynamic env fetch. But that should disappear
817 with magic in the previous code. */
820 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
822 HvARRAY(hv) = (HE**)array;
825 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
827 /* share_hek_flags will do the free for us. This might be considered
829 if (LIKELY(HvSHAREKEYS(hv))) {
831 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
833 else if (UNLIKELY(hv == PL_strtab)) {
834 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
835 this test here is cheap */
836 if (flags & HVhek_FREEKEY)
838 Perl_croak(aTHX_ S_strtab_error,
839 action & HV_FETCH_LVALUE ? "fetch" : "store");
842 /* gotta do the real thing */
844 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
848 #ifdef PERL_HASH_RANDOMIZE_KEYS
849 /* This logic semi-randomizes the insert order in a bucket.
850 * Either we insert into the top, or the slot below the top,
851 * making it harder to see if there is a collision. We also
852 * reset the iterator randomizer if there is one.
854 in_collision = *oentry != NULL;
855 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
857 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
858 if ( PL_hash_rand_bits & 1 ) {
859 HeNEXT(entry) = HeNEXT(*oentry);
860 HeNEXT(*oentry) = entry;
862 HeNEXT(entry) = *oentry;
868 HeNEXT(entry) = *oentry;
871 #ifdef PERL_HASH_RANDOMIZE_KEYS
873 /* Currently this makes various tests warn in annoying ways.
874 * So Silenced for now. - Yves | bogus end of comment =>* /
875 if (HvAUX(hv)->xhv_riter != -1) {
876 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
877 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
882 if (PL_HASH_RAND_BITS_ENABLED) {
883 if (PL_HASH_RAND_BITS_ENABLED == 1)
884 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
885 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
887 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
891 if (val == &PL_sv_placeholder)
892 HvPLACEHOLDERS(hv)++;
893 if (masked_flags & HVhek_ENABLEHVKFLAGS)
896 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
897 if ( in_collision && DO_HSPLIT(xhv) ) {
898 const STRLEN oldsize = xhv->xhv_max + 1;
899 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
901 if (items /* hash has placeholders */
902 && !SvREADONLY(hv) /* but is not a restricted hash */) {
903 /* If this hash previously was a "restricted hash" and had
904 placeholders, but the "restricted" flag has been turned off,
905 then the placeholders no longer serve any useful purpose.
906 However, they have the downsides of taking up RAM, and adding
907 extra steps when finding used values. It's safe to clear them
908 at this point, even though Storable rebuilds restricted hashes by
909 putting in all the placeholders (first) before turning on the
910 readonly flag, because Storable always pre-splits the hash.
911 If we're lucky, then we may clear sufficient placeholders to
912 avoid needing to split the hash at all. */
913 clear_placeholders(hv, items);
915 hsplit(hv, oldsize, oldsize * 2);
917 hsplit(hv, oldsize, oldsize * 2);
921 return entry ? (void *) &HeVAL(entry) : NULL;
923 return (void *) entry;
927 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
929 const MAGIC *mg = SvMAGIC(hv);
931 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
936 if (isUPPER(mg->mg_type)) {
938 if (mg->mg_type == PERL_MAGIC_tied) {
939 *needs_store = FALSE;
940 return; /* We've set all there is to set. */
943 mg = mg->mg_moremagic;
948 =for apidoc hv_scalar
950 Evaluates the hash in scalar context and returns the result.
952 When the hash is tied dispatches through to the SCALAR method,
953 otherwise returns a mortal SV containing the number of keys
956 Note, prior to 5.25 this function returned what is now
957 returned by the hv_bucket_ratio() function.
963 Perl_hv_scalar(pTHX_ HV *hv)
967 PERL_ARGS_ASSERT_HV_SCALAR;
969 if (SvRMAGICAL(hv)) {
970 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
972 return magic_scalarpack(hv, mg);
976 sv_setuv(sv, HvUSEDKEYS(hv));
983 hv_pushkv(): push all the keys and/or values of a hash onto the stack.
984 The rough Perl equivalents:
989 Resets the hash's iterator.
991 flags : 1 = push keys
993 1|2 = push keys and values
994 XXX use symbolic flag constants at some point?
995 I might unroll the non-tied hv_iternext() in here at some point - DAPM
999 Perl_hv_pushkv(pTHX_ HV *hv, U32 flags)
1002 bool tied = SvRMAGICAL(hv) && (mg_find(MUTABLE_SV(hv), PERL_MAGIC_tied)
1003 #ifdef DYNAMIC_ENV_FETCH /* might not know number of keys yet */
1004 || mg_find(MUTABLE_SV(hv), PERL_MAGIC_env)
1009 PERL_ARGS_ASSERT_HV_PUSHKV;
1010 assert(flags); /* must be pushing at least one of keys and values */
1012 (void)hv_iterinit(hv);
1015 SSize_t ext = (flags == 3) ? 2 : 1;
1016 while ((entry = hv_iternext(hv))) {
1019 PUSHs(hv_iterkeysv(entry));
1021 PUSHs(hv_iterval(hv, entry));
1025 Size_t nkeys = HvUSEDKEYS(hv);
1031 /* 2*nkeys() should never be big enough to truncate or wrap */
1032 assert(nkeys <= (SSize_t_MAX >> 1));
1033 ext = nkeys * ((flags == 3) ? 2 : 1);
1035 EXTEND_MORTAL(nkeys);
1038 while ((entry = hv_iternext(hv))) {
1040 SV *keysv = newSVhek(HeKEY_hek(entry));
1042 PL_tmps_stack[++PL_tmps_ix] = keysv;
1046 PUSHs(HeVAL(entry));
1055 =for apidoc hv_bucket_ratio
1057 If the hash is tied dispatches through to the SCALAR tied method,
1058 otherwise if the hash contains no keys returns 0, otherwise returns
1059 a mortal sv containing a string specifying the number of used buckets,
1060 followed by a slash, followed by the number of available buckets.
1062 This function is expensive, it must scan all of the buckets
1063 to determine which are used, and the count is NOT cached.
1064 In a large hash this could be a lot of buckets.
1070 Perl_hv_bucket_ratio(pTHX_ HV *hv)
1074 PERL_ARGS_ASSERT_HV_BUCKET_RATIO;
1076 if (SvRMAGICAL(hv)) {
1077 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
1079 return magic_scalarpack(hv, mg);
1082 if (HvUSEDKEYS((HV *)hv)) {
1083 sv = sv_newmortal();
1084 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
1085 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
1094 =for apidoc hv_delete
1096 Deletes a key/value pair in the hash. The value's SV is removed from
1097 the hash, made mortal, and returned to the caller. The absolute
1098 value of C<klen> is the length of the key. If C<klen> is negative the
1099 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
1100 will normally be zero; if set to C<G_DISCARD> then C<NULL> will be returned.
1101 C<NULL> will also be returned if the key is not found.
1103 =for apidoc hv_delete_ent
1105 Deletes a key/value pair in the hash. The value SV is removed from the hash,
1106 made mortal, and returned to the caller. The C<flags> value will normally be
1107 zero; if set to C<G_DISCARD> then C<NULL> will be returned. C<NULL> will also
1108 be returned if the key is not found. C<hash> can be a valid precomputed hash
1109 value, or 0 to ask for it to be computed.
1115 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
1116 int k_flags, I32 d_flags, U32 hash)
1122 bool is_utf8 = cBOOL(k_flags & HVhek_UTF8);
1124 HEK *keysv_hek = NULL;
1125 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1130 if (SvMAGICAL(hv)) {
1133 hv_magic_check (hv, &needs_copy, &needs_store);
1137 entry = (HE *) hv_common(hv, keysv, key, klen,
1138 k_flags & ~HVhek_FREEKEY,
1139 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
1141 sv = entry ? HeVAL(entry) : NULL;
1143 if (SvMAGICAL(sv)) {
1147 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
1148 /* No longer an element */
1149 sv_unmagic(sv, PERL_MAGIC_tiedelem);
1152 return NULL; /* element cannot be deleted */
1154 #ifdef ENV_IS_CASELESS
1155 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
1156 /* XXX This code isn't UTF8 clean. */
1157 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
1158 if (k_flags & HVhek_FREEKEY) {
1161 key = strupr(SvPVX(keysv));
1170 xhv = (XPVHV*)SvANY(hv);
1171 if (!HvTOTALKEYS(hv))
1174 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1175 const char * const keysave = key;
1176 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1179 k_flags |= HVhek_UTF8;
1181 k_flags &= ~HVhek_UTF8;
1182 if (key != keysave) {
1183 if (k_flags & HVhek_FREEKEY) {
1184 /* This shouldn't happen if our caller does what we expect,
1185 but strictly the API allows it. */
1188 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1192 if (keysv && (SvIsCOW_shared_hash(keysv))) {
1193 if (HvSHAREKEYS(hv))
1194 keysv_hek = SvSHARED_HEK_FROM_PV(SvPVX_const(keysv));
1195 hash = SvSHARED_HASH(keysv);
1198 PERL_HASH(hash, key, klen);
1200 masked_flags = (k_flags & HVhek_MASK);
1202 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1209 /* keysv is actually a HEK in disguise, so we can match just by
1210 * comparing the HEK pointers in the HE chain. There is a slight
1211 * caveat: on something like "\x80", which has both plain and utf8
1212 * representations, perl's hashes do encoding-insensitive lookups,
1213 * but preserve the encoding of the stored key. Thus a particular
1214 * key could map to two different HEKs in PL_strtab. We only
1215 * conclude 'not found' if all the flags are the same; otherwise
1216 * we fall back to a full search (this should only happen in rare
1219 int keysv_flags = HEK_FLAGS(keysv_hek);
1221 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1222 HEK *hek = HeKEY_hek(entry);
1223 if (hek == keysv_hek)
1225 if (HEK_FLAGS(hek) != keysv_flags)
1226 break; /* need to do full match */
1230 /* failed on shortcut - do full search loop */
1231 oentry = first_entry;
1235 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1236 if (HeHASH(entry) != hash) /* strings can't be equal */
1238 if (HeKLEN(entry) != (I32)klen)
1240 if (memNE(HeKEY(entry),key,klen)) /* is this it? */
1242 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1246 if (hv == PL_strtab) {
1247 if (k_flags & HVhek_FREEKEY)
1249 Perl_croak(aTHX_ S_strtab_error, "delete");
1254 /* if placeholder is here, it's already been deleted.... */
1255 if (sv == &PL_sv_placeholder) {
1256 if (k_flags & HVhek_FREEKEY)
1260 if (SvREADONLY(hv) && sv && SvREADONLY(sv)) {
1261 hv_notallowed(k_flags, key, klen,
1262 "Attempt to delete readonly key '%" SVf "' from"
1263 " a restricted hash");
1267 * If a restricted hash, rather than really deleting the entry, put
1268 * a placeholder there. This marks the key as being "approved", so
1269 * we can still access via not-really-existing key without raising
1272 if (SvREADONLY(hv)) {
1273 /* We'll be saving this slot, so the number of allocated keys
1274 * doesn't go down, but the number placeholders goes up */
1275 HeVAL(entry) = &PL_sv_placeholder;
1276 HvPLACEHOLDERS(hv)++;
1279 HeVAL(entry) = NULL;
1280 *oentry = HeNEXT(entry);
1281 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */) {
1285 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1286 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1287 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1288 hv_free_ent(hv, entry);
1290 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1291 if (xhv->xhv_keys == 0)
1292 HvHASKFLAGS_off(hv);
1295 /* If this is a stash and the key ends with ::, then someone is
1296 * deleting a package.
1298 if (sv && HvENAME_get(hv)) {
1301 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1303 (klen == 1 && key[0] == ':')
1305 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1306 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1307 && HvENAME_get(stash)) {
1308 /* A previous version of this code checked that the
1309 * GV was still in the symbol table by fetching the
1310 * GV with its name. That is not necessary (and
1311 * sometimes incorrect), as HvENAME cannot be set
1312 * on hv if it is not in the symtab. */
1314 /* Hang on to it for a bit. */
1315 SvREFCNT_inc_simple_void_NN(
1316 sv_2mortal((SV *)gv)
1319 else if (memEQs(key, klen, "ISA") && GvAV(gv)) {
1321 MAGIC *mg = mg_find((SV*)isa, PERL_MAGIC_isa);
1325 if (mg->mg_obj == (SV*)gv) {
1326 /* This is the only stash this ISA was used for.
1327 * The isaelem magic asserts if there's no
1328 * isa magic on the array, so explicitly
1329 * remove the magic on both the array and its
1330 * elements. @ISA shouldn't be /too/ large.
1335 end = svp + (AvFILLp(isa)+1);
1338 mg_free_type(*svp, PERL_MAGIC_isaelem);
1341 mg_free_type((SV*)GvAV(gv), PERL_MAGIC_isa);
1344 /* mg_obj is an array of stashes
1345 Note that the array doesn't keep a reference
1346 count on the stashes.
1348 AV *av = (AV*)mg->mg_obj;
1353 assert(SvTYPE(mg->mg_obj) == SVt_PVAV);
1355 /* remove the stash from the magic array */
1356 arrayp = svp = AvARRAY(av);
1357 items = AvFILLp(av) + 1;
1359 assert(*arrayp == (SV *)gv);
1361 /* avoid a double free on the last stash */
1363 /* The magic isn't MGf_REFCOUNTED, so release
1364 * the array manually.
1366 SvREFCNT_dec_NN(av);
1371 if (*svp == (SV*)gv)
1375 index = svp - arrayp;
1376 assert(index >= 0 && index <= AvFILLp(av));
1377 if (index < AvFILLp(av)) {
1378 arrayp[index] = arrayp[AvFILLp(av)];
1380 arrayp[AvFILLp(av)] = NULL;
1388 if (k_flags & HVhek_FREEKEY)
1392 /* deletion of method from stash */
1393 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1395 mro_method_changed_in(hv);
1397 if (d_flags & G_DISCARD) {
1406 if (mro_changes == 1) mro_isa_changed_in(hv);
1407 else if (mro_changes == 2)
1408 mro_package_moved(NULL, stash, gv, 1);
1414 if (SvREADONLY(hv)) {
1415 hv_notallowed(k_flags, key, klen,
1416 "Attempt to delete disallowed key '%" SVf "' from"
1417 " a restricted hash");
1420 if (k_flags & HVhek_FREEKEY)
1427 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1430 char *a = (char*) HvARRAY(hv);
1434 /* already have an HvAUX(hv) so we have to move it */
1436 /* no HvAUX() but array we are going to allocate is large enough
1437 * there is no point in saving the space for the iterator, and
1438 * speeds up later traversals. */
1439 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1442 PERL_ARGS_ASSERT_HSPLIT;
1443 if (newsize > MAX_BUCKET_MAX+1)
1447 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1453 #ifdef PERL_HASH_RANDOMIZE_KEYS
1454 /* the idea of this is that we create a "random" value by hashing the address of
1455 * the array, we then use the low bit to decide if we insert at the top, or insert
1456 * second from top. After each such insert we rotate the hashed value. So we can
1457 * use the same hashed value over and over, and in normal build environments use
1458 * very few ops to do so. ROTL32() should produce a single machine operation. */
1459 if (PL_HASH_RAND_BITS_ENABLED) {
1460 if (PL_HASH_RAND_BITS_ENABLED == 1)
1461 PL_hash_rand_bits += ptr_hash((PTRV)a);
1462 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1465 HvARRAY(hv) = (HE**) a;
1466 HvMAX(hv) = newsize - 1;
1467 /* before we zero the newly added memory, we
1468 * need to deal with the aux struct that may be there
1469 * or have been allocated by us*/
1471 struct xpvhv_aux *const dest = HvAUX(hv);
1473 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1474 #ifdef PERL_HASH_RANDOMIZE_KEYS
1475 dest->xhv_rand = (U32)PL_hash_rand_bits;
1478 /* no existing aux structure, but we allocated space for one
1479 * so initialize it properly. This unrolls hv_auxinit() a bit,
1480 * since we have to do the realloc anyway. */
1481 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1482 #ifdef PERL_HASH_RANDOMIZE_KEYS
1483 dest->xhv_rand = (U32)PL_hash_rand_bits;
1485 /* this is the "non realloc" part of the hv_auxinit() */
1486 (void)hv_auxinit_internal(dest);
1487 /* Turn on the OOK flag */
1491 /* now we can safely clear the second half */
1492 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1494 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1500 HE **oentry = aep + i;
1503 if (!entry) /* non-existent */
1506 U32 j = (HeHASH(entry) & newsize);
1508 *oentry = HeNEXT(entry);
1509 #ifdef PERL_HASH_RANDOMIZE_KEYS
1510 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1511 * insert to top, otherwise rotate the bucket rand 1 bit,
1512 * and use the new low bit to decide if we insert at top,
1513 * or next from top. IOW, we only rotate on a collision.*/
1514 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1515 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1516 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1517 if (PL_hash_rand_bits & 1) {
1518 HeNEXT(entry)= HeNEXT(aep[j]);
1519 HeNEXT(aep[j])= entry;
1521 /* Note, this is structured in such a way as the optimizer
1522 * should eliminate the duplicated code here and below without
1523 * us needing to explicitly use a goto. */
1524 HeNEXT(entry) = aep[j];
1530 /* see comment above about duplicated code */
1531 HeNEXT(entry) = aep[j];
1536 oentry = &HeNEXT(entry);
1540 } while (i++ < oldsize);
1544 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1546 XPVHV* xhv = (XPVHV*)SvANY(hv);
1547 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 */
1553 PERL_ARGS_ASSERT_HV_KSPLIT;
1555 wantsize = (I32) newmax; /* possible truncation here */
1556 if (wantsize != newmax)
1559 wantsize= wantsize + (wantsize >> 1); /* wantsize *= 1.5 */
1560 if (wantsize < newmax) /* overflow detection */
1564 while (wantsize > newsize) {
1565 trysize = newsize << 1;
1566 if (trysize > newsize) {
1574 if (newsize <= oldsize)
1575 return; /* overflow detection */
1577 a = (char *) HvARRAY(hv);
1579 hsplit(hv, oldsize, newsize);
1581 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1582 xhv->xhv_max = newsize - 1;
1583 HvARRAY(hv) = (HE **) a;
1587 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1588 * as tied hashes could play silly buggers and mess us around. We will
1589 * do the right thing during hv_store() afterwards, but still - Yves */
1590 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1591 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1592 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1593 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1595 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1596 hv_max = hv_max / 2; \
1598 HvMAX(hv) = hv_max; \
1603 Perl_newHVhv(pTHX_ HV *ohv)
1605 HV * const hv = newHV();
1608 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1610 hv_max = HvMAX(ohv);
1612 if (!SvMAGICAL((const SV *)ohv)) {
1613 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1615 const bool shared = !!HvSHAREKEYS(ohv);
1616 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1618 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1621 /* In each bucket... */
1622 for (i = 0; i <= hv_max; i++) {
1624 HE *oent = oents[i];
1631 /* Copy the linked list of entries. */
1632 for (; oent; oent = HeNEXT(oent)) {
1633 const U32 hash = HeHASH(oent);
1634 const char * const key = HeKEY(oent);
1635 const STRLEN len = HeKLEN(oent);
1636 const int flags = HeKFLAGS(oent);
1637 HE * const ent = new_HE();
1638 SV *const val = HeVAL(oent);
1640 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1642 = shared ? share_hek_flags(key, len, hash, flags)
1643 : save_hek_flags(key, len, hash, flags);
1654 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1658 /* Iterate over ohv, copying keys and values one at a time. */
1660 const I32 riter = HvRITER_get(ohv);
1661 HE * const eiter = HvEITER_get(ohv);
1662 STRLEN hv_keys = HvTOTALKEYS(ohv);
1664 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1667 while ((entry = hv_iternext_flags(ohv, 0))) {
1668 SV *val = hv_iterval(ohv,entry);
1669 SV * const keysv = HeSVKEY(entry);
1670 val = SvIMMORTAL(val) ? val : newSVsv(val);
1672 (void)hv_store_ent(hv, keysv, val, 0);
1674 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1675 HeHASH(entry), HeKFLAGS(entry));
1677 HvRITER_set(ohv, riter);
1678 HvEITER_set(ohv, eiter);
1685 =for apidoc hv_copy_hints_hv
1687 A specialised version of L</newHVhv> for copying C<%^H>. C<ohv> must be
1688 a pointer to a hash (which may have C<%^H> magic, but should be generally
1689 non-magical), or C<NULL> (interpreted as an empty hash). The content
1690 of C<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1691 added to it. A pointer to the new hash is returned.
1697 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1699 HV * const hv = newHV();
1702 STRLEN hv_max = HvMAX(ohv);
1703 STRLEN hv_keys = HvTOTALKEYS(ohv);
1705 const I32 riter = HvRITER_get(ohv);
1706 HE * const eiter = HvEITER_get(ohv);
1711 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1714 while ((entry = hv_iternext_flags(ohv, 0))) {
1715 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1716 SV *heksv = HeSVKEY(entry);
1717 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1718 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1719 (char *)heksv, HEf_SVKEY);
1720 if (heksv == HeSVKEY(entry))
1721 (void)hv_store_ent(hv, heksv, sv, 0);
1723 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1724 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1725 SvREFCNT_dec_NN(heksv);
1728 HvRITER_set(ohv, riter);
1729 HvEITER_set(ohv, eiter);
1731 SvREFCNT_inc_simple_void_NN(hv);
1734 hv_magic(hv, NULL, PERL_MAGIC_hints);
1737 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1739 /* like hv_free_ent, but returns the SV rather than freeing it */
1741 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1745 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1748 if (HeKLEN(entry) == HEf_SVKEY) {
1749 SvREFCNT_dec(HeKEY_sv(entry));
1750 Safefree(HeKEY_hek(entry));
1752 else if (HvSHAREKEYS(hv))
1753 unshare_hek(HeKEY_hek(entry));
1755 Safefree(HeKEY_hek(entry));
1762 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1766 PERL_ARGS_ASSERT_HV_FREE_ENT;
1770 val = hv_free_ent_ret(hv, entry);
1776 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1778 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1782 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1783 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1784 if (HeKLEN(entry) == HEf_SVKEY) {
1785 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1787 hv_free_ent(hv, entry);
1791 =for apidoc hv_clear
1793 Frees all the elements of a hash, leaving it empty.
1794 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1796 See L</av_clear> for a note about the hash possibly being invalid on
1803 Perl_hv_clear(pTHX_ HV *hv)
1811 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1813 xhv = (XPVHV*)SvANY(hv);
1815 /* avoid hv being freed when calling destructors below */
1817 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
1818 orig_ix = PL_tmps_ix;
1819 if (SvREADONLY(hv) && HvTOTALKEYS(hv)) {
1820 /* restricted hash: convert all keys to placeholders */
1822 for (i = 0; i <= xhv->xhv_max; i++) {
1823 HE *entry = (HvARRAY(hv))[i];
1824 for (; entry; entry = HeNEXT(entry)) {
1825 /* not already placeholder */
1826 if (HeVAL(entry) != &PL_sv_placeholder) {
1828 if (SvREADONLY(HeVAL(entry))) {
1829 SV* const keysv = hv_iterkeysv(entry);
1830 Perl_croak_nocontext(
1831 "Attempt to delete readonly key '%" SVf "' from a restricted hash",
1834 SvREFCNT_dec_NN(HeVAL(entry));
1836 HeVAL(entry) = &PL_sv_placeholder;
1837 HvPLACEHOLDERS(hv)++;
1843 hv_free_entries(hv);
1844 HvPLACEHOLDERS_set(hv, 0);
1847 mg_clear(MUTABLE_SV(hv));
1849 HvHASKFLAGS_off(hv);
1853 mro_isa_changed_in(hv);
1854 HvEITER_set(hv, NULL);
1856 /* disarm hv's premature free guard */
1857 if (LIKELY(PL_tmps_ix == orig_ix))
1860 PL_tmps_stack[orig_ix] = &PL_sv_undef;
1861 SvREFCNT_dec_NN(hv);
1865 =for apidoc hv_clear_placeholders
1867 Clears any placeholders from a hash. If a restricted hash has any of its keys
1868 marked as readonly and the key is subsequently deleted, the key is not actually
1869 deleted but is marked by assigning it a value of C<&PL_sv_placeholder>. This tags
1870 it so it will be ignored by future operations such as iterating over the hash,
1871 but will still allow the hash to have a value reassigned to the key at some
1872 future point. This function clears any such placeholder keys from the hash.
1873 See C<L<Hash::Util::lock_keys()|Hash::Util/lock_keys>> for an example of its
1880 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1882 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1884 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1887 clear_placeholders(hv, items);
1891 S_clear_placeholders(pTHX_ HV *hv, const U32 placeholders)
1894 U32 to_find = placeholders;
1896 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1902 /* Loop down the linked list heads */
1903 HE **oentry = &(HvARRAY(hv))[i];
1906 while ((entry = *oentry)) {
1907 if (HeVAL(entry) == &PL_sv_placeholder) {
1908 *oentry = HeNEXT(entry);
1909 if (entry == HvEITER_get(hv))
1912 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1913 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1914 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1915 hv_free_ent(hv, entry);
1918 if (--to_find == 0) {
1920 HvTOTALKEYS(hv) -= (IV)placeholders;
1921 if (HvTOTALKEYS(hv) == 0)
1922 HvHASKFLAGS_off(hv);
1923 HvPLACEHOLDERS_set(hv, 0);
1927 oentry = &HeNEXT(entry);
1931 /* You can't get here, hence assertion should always fail. */
1932 assert (to_find == 0);
1933 NOT_REACHED; /* NOTREACHED */
1937 S_hv_free_entries(pTHX_ HV *hv)
1940 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1943 PERL_ARGS_ASSERT_HV_FREE_ENTRIES;
1945 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1951 /* hfree_next_entry()
1952 * For use only by S_hv_free_entries() and sv_clear().
1953 * Delete the next available HE from hv and return the associated SV.
1954 * Returns null on empty hash. Nevertheless null is not a reliable
1955 * indicator that the hash is empty, as the deleted entry may have a
1957 * indexp is a pointer to the current index into HvARRAY. The index should
1958 * initially be set to 0. hfree_next_entry() may update it. */
1961 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1963 struct xpvhv_aux *iter;
1967 STRLEN orig_index = *indexp;
1970 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1972 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1973 if ((entry = iter->xhv_eiter)) {
1974 /* the iterator may get resurrected after each
1975 * destructor call, so check each time */
1976 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1978 hv_free_ent(hv, entry);
1979 /* warning: at this point HvARRAY may have been
1980 * re-allocated, HvMAX changed etc */
1982 iter = HvAUX(hv); /* may have been realloced */
1983 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1984 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1985 #ifdef PERL_HASH_RANDOMIZE_KEYS
1986 iter->xhv_last_rand = iter->xhv_rand;
1991 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1994 array = HvARRAY(hv);
1996 while ( ! ((entry = array[*indexp])) ) {
1997 if ((*indexp)++ >= HvMAX(hv))
1999 assert(*indexp != orig_index);
2001 array[*indexp] = HeNEXT(entry);
2002 ((XPVHV*) SvANY(hv))->xhv_keys--;
2004 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
2005 && HeVAL(entry) && isGV(HeVAL(entry))
2006 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
2009 const char * const key = HePV(entry,klen);
2010 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
2011 || (klen == 1 && key[0] == ':')) {
2013 NULL, GvHV(HeVAL(entry)),
2014 (GV *)HeVAL(entry), 0
2018 return hv_free_ent_ret(hv, entry);
2023 =for apidoc hv_undef
2025 Undefines the hash. The XS equivalent of C<undef(%hash)>.
2027 As well as freeing all the elements of the hash (like C<hv_clear()>), this
2028 also frees any auxiliary data and storage associated with the hash.
2030 See L</av_clear> for a note about the hash possibly being invalid on
2037 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
2041 SSize_t orig_ix = PL_tmps_ix; /* silence compiler warning about unitialized vars */
2045 save = cBOOL(SvREFCNT(hv));
2046 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2047 xhv = (XPVHV*)SvANY(hv);
2049 /* The name must be deleted before the call to hv_free_entries so that
2050 CVs are anonymised properly. But the effective name must be pre-
2051 served until after that call (and only deleted afterwards if the
2052 call originated from sv_clear). For stashes with one name that is
2053 both the canonical name and the effective name, hv_name_set has to
2054 allocate an array for storing the effective name. We can skip that
2055 during global destruction, as it does not matter where the CVs point
2056 if they will be freed anyway. */
2057 /* note that the code following prior to hv_free_entries is duplicated
2058 * in sv_clear(), and changes here should be done there too */
2059 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
2060 if (PL_stashcache) {
2061 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
2062 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2063 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2065 hv_name_set(hv, NULL, 0, 0);
2068 /* avoid hv being freed when calling destructors below */
2070 PL_tmps_stack[++PL_tmps_ix] = SvREFCNT_inc_simple_NN(hv);
2071 orig_ix = PL_tmps_ix;
2073 hv_free_entries(hv);
2075 struct mro_meta *meta;
2078 if (HvENAME_get(hv)) {
2079 if (PL_phase != PERL_PHASE_DESTRUCT)
2080 mro_isa_changed_in(hv);
2081 if (PL_stashcache) {
2082 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
2083 HEKf "'\n", HEKfARG(HvENAME_HEK(hv))));
2084 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
2088 /* If this call originated from sv_clear, then we must check for
2089 * effective names that need freeing, as well as the usual name. */
2091 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
2092 if (name && PL_stashcache) {
2093 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
2094 HEKf "'\n", HEKfARG(HvNAME_HEK(hv))));
2095 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
2097 hv_name_set(hv, NULL, 0, flags);
2099 if((meta = HvAUX(hv)->xhv_mro_meta)) {
2100 if (meta->mro_linear_all) {
2101 SvREFCNT_dec_NN(meta->mro_linear_all);
2102 /* mro_linear_current is just acting as a shortcut pointer,
2106 /* Only the current MRO is stored, so this owns the data.
2108 SvREFCNT_dec(meta->mro_linear_current);
2109 SvREFCNT_dec(meta->mro_nextmethod);
2110 SvREFCNT_dec(meta->isa);
2111 SvREFCNT_dec(meta->super);
2113 HvAUX(hv)->xhv_mro_meta = NULL;
2115 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
2116 SvFLAGS(hv) &= ~SVf_OOK;
2119 Safefree(HvARRAY(hv));
2120 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
2123 /* if we're freeing the HV, the SvMAGIC field has been reused for
2124 * other purposes, and so there can't be any placeholder magic */
2126 HvPLACEHOLDERS_set(hv, 0);
2129 mg_clear(MUTABLE_SV(hv));
2132 /* disarm hv's premature free guard */
2133 if (LIKELY(PL_tmps_ix == orig_ix))
2136 PL_tmps_stack[orig_ix] = &PL_sv_undef;
2137 SvREFCNT_dec_NN(hv);
2144 Returns the number of hash buckets that happen to be in use.
2146 This function is wrapped by the macro C<HvFILL>.
2148 As of perl 5.25 this function is used only for debugging
2149 purposes, and the number of used hash buckets is not
2150 in any way cached, thus this function can be costly
2151 to execute as it must iterate over all the buckets in the
2158 Perl_hv_fill(pTHX_ HV *const hv)
2161 HE **ents = HvARRAY(hv);
2163 PERL_UNUSED_CONTEXT;
2164 PERL_ARGS_ASSERT_HV_FILL;
2166 /* No keys implies no buckets used.
2167 One key can only possibly mean one bucket used. */
2168 if (HvTOTALKEYS(hv) < 2)
2169 return HvTOTALKEYS(hv);
2172 /* I wonder why we count down here...
2173 * Is it some micro-optimisation?
2174 * I would have thought counting up was better.
2177 HE *const *const last = ents + HvMAX(hv);
2178 count = last + 1 - ents;
2183 } while (++ents <= last);
2188 /* hash a pointer to a U32 - Used in the hash traversal randomization
2189 * and bucket order randomization code
2191 * this code was derived from Sereal, which was derived from autobox.
2194 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
2197 * This is one of Thomas Wang's hash functions for 64-bit integers from:
2198 * http://www.concentric.net/~Ttwang/tech/inthash.htm
2200 u = (~u) + (u << 18);
2208 * This is one of Bob Jenkins' hash functions for 32-bit integers
2209 * from: http://burtleburtle.net/bob/hash/integer.html
2211 u = (u + 0x7ed55d16) + (u << 12);
2212 u = (u ^ 0xc761c23c) ^ (u >> 19);
2213 u = (u + 0x165667b1) + (u << 5);
2214 u = (u + 0xd3a2646c) ^ (u << 9);
2215 u = (u + 0xfd7046c5) + (u << 3);
2216 u = (u ^ 0xb55a4f09) ^ (u >> 16);
2221 static struct xpvhv_aux*
2222 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
2223 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
2224 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2225 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2226 #ifdef PERL_HASH_RANDOMIZE_KEYS
2227 iter->xhv_last_rand = iter->xhv_rand;
2229 iter->xhv_name_u.xhvnameu_name = 0;
2230 iter->xhv_name_count = 0;
2231 iter->xhv_backreferences = 0;
2232 iter->xhv_mro_meta = NULL;
2233 iter->xhv_aux_flags = 0;
2238 static struct xpvhv_aux*
2239 S_hv_auxinit(pTHX_ HV *hv) {
2240 struct xpvhv_aux *iter;
2243 PERL_ARGS_ASSERT_HV_AUXINIT;
2247 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2249 array = (char *) HvARRAY(hv);
2250 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1), char);
2252 HvARRAY(hv) = (HE**)array;
2255 #ifdef PERL_HASH_RANDOMIZE_KEYS
2256 if (PL_HASH_RAND_BITS_ENABLED) {
2257 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2258 if (PL_HASH_RAND_BITS_ENABLED == 1)
2259 PL_hash_rand_bits += ptr_hash((PTRV)array);
2260 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2262 iter->xhv_rand = (U32)PL_hash_rand_bits;
2268 return hv_auxinit_internal(iter);
2272 =for apidoc hv_iterinit
2274 Prepares a starting point to traverse a hash table. Returns the number of
2275 keys in the hash, including placeholders (i.e. the same as C<HvTOTALKEYS(hv)>).
2276 The return value is currently only meaningful for hashes without tie magic.
2278 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2279 hash buckets that happen to be in use. If you still need that esoteric
2280 value, you can get it through the macro C<HvFILL(hv)>.
2287 Perl_hv_iterinit(pTHX_ HV *hv)
2289 PERL_ARGS_ASSERT_HV_ITERINIT;
2292 struct xpvhv_aux * iter = HvAUX(hv);
2293 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2294 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2296 hv_free_ent(hv, entry);
2298 iter = HvAUX(hv); /* may have been reallocated */
2299 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2300 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2301 #ifdef PERL_HASH_RANDOMIZE_KEYS
2302 iter->xhv_last_rand = iter->xhv_rand;
2308 /* note this includes placeholders! */
2309 return HvTOTALKEYS(hv);
2313 Perl_hv_riter_p(pTHX_ HV *hv) {
2314 struct xpvhv_aux *iter;
2316 PERL_ARGS_ASSERT_HV_RITER_P;
2318 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2319 return &(iter->xhv_riter);
2323 Perl_hv_eiter_p(pTHX_ HV *hv) {
2324 struct xpvhv_aux *iter;
2326 PERL_ARGS_ASSERT_HV_EITER_P;
2328 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2329 return &(iter->xhv_eiter);
2333 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2334 struct xpvhv_aux *iter;
2336 PERL_ARGS_ASSERT_HV_RITER_SET;
2344 iter = hv_auxinit(hv);
2346 iter->xhv_riter = riter;
2350 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2351 struct xpvhv_aux *iter;
2353 PERL_ARGS_ASSERT_HV_RAND_SET;
2355 #ifdef PERL_HASH_RANDOMIZE_KEYS
2359 iter = hv_auxinit(hv);
2361 iter->xhv_rand = new_xhv_rand;
2363 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2368 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2369 struct xpvhv_aux *iter;
2371 PERL_ARGS_ASSERT_HV_EITER_SET;
2376 /* 0 is the default so don't go malloc()ing a new structure just to
2381 iter = hv_auxinit(hv);
2383 iter->xhv_eiter = eiter;
2387 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2389 struct xpvhv_aux *iter;
2393 PERL_ARGS_ASSERT_HV_NAME_SET;
2396 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2400 if (iter->xhv_name_u.xhvnameu_name) {
2401 if(iter->xhv_name_count) {
2402 if(flags & HV_NAME_SETALL) {
2403 HEK ** const this_name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2404 HEK **hekp = this_name + (
2405 iter->xhv_name_count < 0
2406 ? -iter->xhv_name_count
2407 : iter->xhv_name_count
2409 while(hekp-- > this_name+1)
2410 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2411 /* The first elem may be null. */
2412 if(*this_name) unshare_hek_or_pvn(*this_name, 0, 0, 0);
2413 Safefree(this_name);
2414 iter = HvAUX(hv); /* may been realloced */
2415 spot = &iter->xhv_name_u.xhvnameu_name;
2416 iter->xhv_name_count = 0;
2419 if(iter->xhv_name_count > 0) {
2420 /* shift some things over */
2422 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2424 spot = iter->xhv_name_u.xhvnameu_names;
2425 spot[iter->xhv_name_count] = spot[1];
2427 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2429 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2430 unshare_hek_or_pvn(*spot, 0, 0, 0);
2434 else if (flags & HV_NAME_SETALL) {
2435 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2436 iter = HvAUX(hv); /* may been realloced */
2437 spot = &iter->xhv_name_u.xhvnameu_name;
2440 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2441 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2442 iter->xhv_name_count = -2;
2443 spot = iter->xhv_name_u.xhvnameu_names;
2444 spot[1] = existing_name;
2447 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2452 iter = hv_auxinit(hv);
2453 spot = &iter->xhv_name_u.xhvnameu_name;
2455 PERL_HASH(hash, name, len);
2456 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2460 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2465 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2466 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2467 if (flags & SVf_UTF8)
2468 return (bytes_cmp_utf8(
2469 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2470 (const U8*)pv, pvlen) == 0);
2472 return (bytes_cmp_utf8(
2473 (const U8*)pv, pvlen,
2474 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2477 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2478 || memEQ(HEK_KEY(hek), pv, pvlen));
2482 =for apidoc hv_ename_add
2484 Adds a name to a stash's internal list of effective names. See
2485 C<L</hv_ename_delete>>.
2487 This is called when a stash is assigned to a new location in the symbol
2494 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2496 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2499 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2502 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2504 PERL_HASH(hash, name, len);
2506 if (aux->xhv_name_count) {
2507 I32 count = aux->xhv_name_count;
2508 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names + (count<0);
2509 HEK **hekp = xhv_name + (count < 0 ? -count - 1 : count);
2510 while (hekp-- > xhv_name)
2514 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2515 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2516 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2518 if (hekp == xhv_name && count < 0)
2519 aux->xhv_name_count = -count;
2523 if (count < 0) aux->xhv_name_count--, count = -count;
2524 else aux->xhv_name_count++;
2525 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2526 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2529 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2532 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2533 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2534 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2537 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2538 aux->xhv_name_count = existing_name ? 2 : -2;
2539 *aux->xhv_name_u.xhvnameu_names = existing_name;
2540 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2545 =for apidoc hv_ename_delete
2547 Removes a name from a stash's internal list of effective names. If this is
2548 the name returned by C<HvENAME>, then another name in the list will take
2549 its place (C<HvENAME> will use it).
2551 This is called when a stash is deleted from the symbol table.
2557 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2559 struct xpvhv_aux *aux;
2561 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2564 Perl_croak(aTHX_ "panic: hv name too long (%" UVuf ")", (UV) len);
2566 if (!SvOOK(hv)) return;
2569 if (!aux->xhv_name_u.xhvnameu_name) return;
2571 if (aux->xhv_name_count) {
2572 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2573 I32 const count = aux->xhv_name_count;
2574 HEK **victim = namep + (count < 0 ? -count : count);
2575 while (victim-- > namep + 1)
2577 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2578 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2579 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2581 unshare_hek_or_pvn(*victim, 0, 0, 0);
2582 aux = HvAUX(hv); /* may been realloced */
2583 if (count < 0) ++aux->xhv_name_count;
2584 else --aux->xhv_name_count;
2586 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2588 ) { /* if there are none left */
2590 aux->xhv_name_u.xhvnameu_names = NULL;
2591 aux->xhv_name_count = 0;
2594 /* Move the last one back to fill the empty slot. It
2595 does not matter what order they are in. */
2596 *victim = *(namep + (count < 0 ? -count : count) - 1);
2601 count > 0 && ((HEK_UTF8(*namep) || (flags & SVf_UTF8))
2602 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2603 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2606 aux->xhv_name_count = -count;
2610 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2611 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2612 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2613 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2615 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2616 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2617 *aux->xhv_name_u.xhvnameu_names = namehek;
2618 aux->xhv_name_count = -1;
2623 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2624 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2625 /* See also Perl_sv_get_backrefs in sv.c where this logic is unrolled */
2627 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2628 return &(iter->xhv_backreferences);
2633 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2636 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2641 av = HvAUX(hv)->xhv_backreferences;
2644 HvAUX(hv)->xhv_backreferences = 0;
2645 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2646 if (SvTYPE(av) == SVt_PVAV)
2647 SvREFCNT_dec_NN(av);
2652 hv_iternext is implemented as a macro in hv.h
2654 =for apidoc hv_iternext
2656 Returns entries from a hash iterator. See C<L</hv_iterinit>>.
2658 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2659 iterator currently points to, without losing your place or invalidating your
2660 iterator. Note that in this case the current entry is deleted from the hash
2661 with your iterator holding the last reference to it. Your iterator is flagged
2662 to free the entry on the next call to C<hv_iternext>, so you must not discard
2663 your iterator immediately else the entry will leak - call C<hv_iternext> to
2664 trigger the resource deallocation.
2666 =for apidoc hv_iternext_flags
2668 Returns entries from a hash iterator. See C<L</hv_iterinit>> and
2670 The C<flags> value will normally be zero; if C<HV_ITERNEXT_WANTPLACEHOLDERS> is
2671 set the placeholders keys (for restricted hashes) will be returned in addition
2672 to normal keys. By default placeholders are automatically skipped over.
2673 Currently a placeholder is implemented with a value that is
2674 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2675 restricted hashes may change, and the implementation currently is
2676 insufficiently abstracted for any change to be tidy.
2678 =for apidoc Amnh||HV_ITERNEXT_WANTPLACEHOLDERS
2684 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2689 struct xpvhv_aux *iter;
2691 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2694 /* Too many things (well, pp_each at least) merrily assume that you can
2695 call hv_iternext without calling hv_iterinit, so we'll have to deal
2701 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2702 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2703 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2704 SV * const key = sv_newmortal();
2706 sv_setsv(key, HeSVKEY_force(entry));
2707 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2708 HeSVKEY_set(entry, NULL);
2714 /* one HE per MAGICAL hash */
2715 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2716 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2718 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2720 HeKEY_hek(entry) = hek;
2721 HeKLEN(entry) = HEf_SVKEY;
2723 magic_nextpack(MUTABLE_SV(hv),mg,key);
2725 /* force key to stay around until next time */
2726 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2727 return entry; /* beware, hent_val is not set */
2729 SvREFCNT_dec(HeVAL(entry));
2730 Safefree(HeKEY_hek(entry));
2732 iter = HvAUX(hv); /* may been realloced */
2733 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2738 #if defined(DYNAMIC_ENV_FETCH) && defined(VMS) /* set up %ENV for iteration */
2739 if (!entry && SvRMAGICAL((const SV *)hv)
2740 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2742 /* The prime_env_iter() on VMS just loaded up new hash values
2743 * so HvARRAY() liked has been reallocated
2749 /* hv_iterinit now ensures this. */
2750 assert (HvARRAY(hv));
2752 /* At start of hash, entry is NULL. */
2755 entry = HeNEXT(entry);
2756 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2758 * Skip past any placeholders -- don't want to include them in
2761 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2762 entry = HeNEXT(entry);
2767 #ifdef PERL_HASH_RANDOMIZE_KEYS
2768 if (iter->xhv_last_rand != iter->xhv_rand) {
2769 if (iter->xhv_riter != -1) {
2770 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2771 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2775 iter = HvAUX(hv); /* may been realloced */
2776 iter->xhv_last_rand = iter->xhv_rand;
2780 /* Skip the entire loop if the hash is empty. */
2781 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2782 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2783 STRLEN max = HvMAX(hv);
2785 /* OK. Come to the end of the current list. Grab the next one. */
2787 iter->xhv_riter++; /* HvRITER(hv)++ */
2788 if (iter->xhv_riter > (I32)max /* HvRITER(hv) > HvMAX(hv) */) {
2789 /* There is no next one. End of the hash. */
2790 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2791 #ifdef PERL_HASH_RANDOMIZE_KEYS
2792 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2796 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & max ];
2798 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2799 /* If we have an entry, but it's a placeholder, don't count it.
2801 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2802 entry = HeNEXT(entry);
2804 /* Will loop again if this linked list starts NULL
2805 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2806 or if we run through it and find only placeholders. */
2810 iter->xhv_riter = -1;
2811 #ifdef PERL_HASH_RANDOMIZE_KEYS
2812 iter->xhv_last_rand = iter->xhv_rand;
2816 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2818 hv_free_ent(hv, oldentry);
2821 iter = HvAUX(hv); /* may been realloced */
2822 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2827 =for apidoc hv_iterkey
2829 Returns the key from the current position of the hash iterator. See
2836 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2838 PERL_ARGS_ASSERT_HV_ITERKEY;
2840 if (HeKLEN(entry) == HEf_SVKEY) {
2842 char * const p = SvPV(HeKEY_sv(entry), len);
2847 *retlen = HeKLEN(entry);
2848 return HeKEY(entry);
2852 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2854 =for apidoc hv_iterkeysv
2856 Returns the key as an C<SV*> from the current position of the hash
2857 iterator. The return value will always be a mortal copy of the key. Also
2858 see C<L</hv_iterinit>>.
2864 Perl_hv_iterkeysv(pTHX_ HE *entry)
2866 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2868 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2872 =for apidoc hv_iterval
2874 Returns the value from the current position of the hash iterator. See
2881 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2883 PERL_ARGS_ASSERT_HV_ITERVAL;
2885 if (SvRMAGICAL(hv)) {
2886 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2887 SV* const sv = sv_newmortal();
2888 if (HeKLEN(entry) == HEf_SVKEY)
2889 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2891 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2895 return HeVAL(entry);
2899 =for apidoc hv_iternextsv
2901 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2908 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2910 HE * const he = hv_iternext_flags(hv, 0);
2912 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2916 *key = hv_iterkey(he, retlen);
2917 return hv_iterval(hv, he);
2924 =for apidoc hv_magic
2926 Adds magic to a hash. See C<L</sv_magic>>.
2931 /* possibly free a shared string if no one has access to it
2932 * len and hash must both be valid for str.
2935 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2937 unshare_hek_or_pvn (NULL, str, len, hash);
2942 Perl_unshare_hek(pTHX_ HEK *hek)
2945 unshare_hek_or_pvn(hek, NULL, 0, 0);
2948 /* possibly free a shared string if no one has access to it
2949 hek if non-NULL takes priority over the other 3, else str, len and hash
2950 are used. If so, len and hash must both be valid for str.
2953 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2958 bool is_utf8 = FALSE;
2960 const char * const save = str;
2961 struct shared_he *he = NULL;
2964 /* Find the shared he which is just before us in memory. */
2965 he = (struct shared_he *)(((char *)hek)
2966 - STRUCT_OFFSET(struct shared_he,
2969 /* Assert that the caller passed us a genuine (or at least consistent)
2971 assert (he->shared_he_he.hent_hek == hek);
2973 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2974 --he->shared_he_he.he_valu.hent_refcount;
2978 hash = HEK_HASH(hek);
2979 } else if (len < 0) {
2980 STRLEN tmplen = -len;
2982 /* See the note in hv_fetch(). --jhi */
2983 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2986 k_flags = HVhek_UTF8;
2988 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2991 /* what follows was the moral equivalent of:
2992 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2994 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2996 xhv = (XPVHV*)SvANY(PL_strtab);
2997 /* assert(xhv_array != 0) */
2998 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
3000 const HE *const he_he = &(he->shared_he_he);
3001 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3006 const int flags_masked = k_flags & HVhek_MASK;
3007 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
3008 if (HeHASH(entry) != hash) /* strings can't be equal */
3010 if (HeKLEN(entry) != len)
3012 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3014 if (HeKFLAGS(entry) != flags_masked)
3021 if (--entry->he_valu.hent_refcount == 0) {
3022 *oentry = HeNEXT(entry);
3024 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
3029 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
3030 "Attempt to free nonexistent shared string '%s'%s"
3032 hek ? HEK_KEY(hek) : str,
3033 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
3034 if (k_flags & HVhek_FREEKEY)
3038 /* get a (constant) string ptr from the global string table
3039 * string will get added if it is not already there.
3040 * len and hash must both be valid for str.
3043 Perl_share_hek(pTHX_ const char *str, SSize_t len, U32 hash)
3045 bool is_utf8 = FALSE;
3047 const char * const save = str;
3049 PERL_ARGS_ASSERT_SHARE_HEK;
3052 STRLEN tmplen = -len;
3054 /* See the note in hv_fetch(). --jhi */
3055 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
3057 /* If we were able to downgrade here, then than means that we were passed
3058 in a key which only had chars 0-255, but was utf8 encoded. */
3061 /* If we found we were able to downgrade the string to bytes, then
3062 we should flag that it needs upgrading on keys or each. Also flag
3063 that we need share_hek_flags to free the string. */
3065 PERL_HASH(hash, str, len);
3066 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
3070 return share_hek_flags (str, len, hash, flags);
3074 S_share_hek_flags(pTHX_ const char *str, STRLEN len, U32 hash, int flags)
3077 const int flags_masked = flags & HVhek_MASK;
3078 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
3079 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
3081 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
3083 if (UNLIKELY(len > (STRLEN) I32_MAX)) {
3084 Perl_croak_nocontext("Sorry, hash keys must be smaller than 2**31 bytes");
3087 /* what follows is the moral equivalent of:
3089 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
3090 hv_store(PL_strtab, str, len, NULL, hash);
3092 Can't rehash the shared string table, so not sure if it's worth
3093 counting the number of entries in the linked list
3096 /* assert(xhv_array != 0) */
3097 entry = (HvARRAY(PL_strtab))[hindex];
3098 for (;entry; entry = HeNEXT(entry)) {
3099 if (HeHASH(entry) != hash) /* strings can't be equal */
3101 if (HeKLEN(entry) != (SSize_t) len)
3103 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
3105 if (HeKFLAGS(entry) != flags_masked)
3111 /* What used to be head of the list.
3112 If this is NULL, then we're the first entry for this slot, which
3113 means we need to increate fill. */
3114 struct shared_he *new_entry;
3117 HE **const head = &HvARRAY(PL_strtab)[hindex];
3118 HE *const next = *head;
3120 /* We don't actually store a HE from the arena and a regular HEK.
3121 Instead we allocate one chunk of memory big enough for both,
3122 and put the HEK straight after the HE. This way we can find the
3123 HE directly from the HEK.
3126 Newx(k, STRUCT_OFFSET(struct shared_he,
3127 shared_he_hek.hek_key[0]) + len + 2, char);
3128 new_entry = (struct shared_he *)k;
3129 entry = &(new_entry->shared_he_he);
3130 hek = &(new_entry->shared_he_hek);
3132 Copy(str, HEK_KEY(hek), len, char);
3133 HEK_KEY(hek)[len] = 0;
3135 HEK_HASH(hek) = hash;
3136 HEK_FLAGS(hek) = (unsigned char)flags_masked;
3138 /* Still "point" to the HEK, so that other code need not know what
3140 HeKEY_hek(entry) = hek;
3141 entry->he_valu.hent_refcount = 0;
3142 HeNEXT(entry) = next;
3145 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
3146 if (!next) { /* initial entry? */
3147 } else if ( DO_HSPLIT(xhv) ) {
3148 const STRLEN oldsize = xhv->xhv_max + 1;
3149 hsplit(PL_strtab, oldsize, oldsize * 2);
3153 ++entry->he_valu.hent_refcount;
3155 if (flags & HVhek_FREEKEY)
3158 return HeKEY_hek(entry);
3162 Perl_hv_placeholders_p(pTHX_ HV *hv)
3164 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3166 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
3169 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
3172 Perl_die(aTHX_ "panic: hv_placeholders_p");
3175 return &(mg->mg_len);
3180 Perl_hv_placeholders_get(pTHX_ const HV *hv)
3182 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3184 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
3185 PERL_UNUSED_CONTEXT;
3187 return mg ? mg->mg_len : 0;
3191 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
3193 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
3195 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
3200 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
3201 Perl_die(aTHX_ "panic: hv_placeholders_set");
3203 /* else we don't need to add magic to record 0 placeholders. */
3207 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
3211 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
3213 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
3218 value = &PL_sv_placeholder;
3221 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3224 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3227 case HVrhek_PV_UTF8:
3228 /* Create a string SV that directly points to the bytes in our
3230 value = newSV_type(SVt_PV);
3231 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3232 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3233 /* This stops anything trying to free it */
3234 SvLEN_set(value, 0);
3236 SvREADONLY_on(value);
3237 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3241 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %" UVxf,
3242 (UV)he->refcounted_he_data[0]);
3248 =for apidoc refcounted_he_chain_2hv
3250 Generates and returns a C<HV *> representing the content of a
3251 C<refcounted_he> chain.
3252 C<flags> is currently unused and must be zero.
3257 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3260 U32 placeholders, max;
3263 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %" UVxf,
3266 /* We could chase the chain once to get an idea of the number of keys,
3267 and call ksplit. But for now we'll make a potentially inefficient
3268 hash with only 8 entries in its array. */
3273 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3274 HvARRAY(hv) = (HE**)array;
3280 U32 hash = chain->refcounted_he_hash;
3282 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3284 HE **oentry = &((HvARRAY(hv))[hash & max]);
3285 HE *entry = *oentry;
3288 for (; entry; entry = HeNEXT(entry)) {
3289 if (HeHASH(entry) == hash) {
3290 /* We might have a duplicate key here. If so, entry is older
3291 than the key we've already put in the hash, so if they are
3292 the same, skip adding entry. */
3294 const STRLEN klen = HeKLEN(entry);
3295 const char *const key = HeKEY(entry);
3296 if (klen == chain->refcounted_he_keylen
3297 && (!!HeKUTF8(entry)
3298 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3299 && memEQ(key, REF_HE_KEY(chain), klen))
3302 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3304 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3305 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3306 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3317 = share_hek_flags(REF_HE_KEY(chain),
3318 chain->refcounted_he_keylen,
3319 chain->refcounted_he_hash,
3320 (chain->refcounted_he_data[0]
3321 & (HVhek_UTF8|HVhek_WASUTF8)));
3323 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3325 value = refcounted_he_value(chain);
3326 if (value == &PL_sv_placeholder)
3328 HeVAL(entry) = value;
3330 /* Link it into the chain. */
3331 HeNEXT(entry) = *oentry;
3337 chain = chain->refcounted_he_next;
3341 clear_placeholders(hv, placeholders);
3344 /* We could check in the loop to see if we encounter any keys with key
3345 flags, but it's probably not worth it, as this per-hash flag is only
3346 really meant as an optimisation for things like Storable. */
3348 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3354 =for apidoc refcounted_he_fetch_pvn
3356 Search along a C<refcounted_he> chain for an entry with the key specified
3357 by C<keypv> and C<keylen>. If C<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3358 bit set, the key octets are interpreted as UTF-8, otherwise they
3359 are interpreted as Latin-1. C<hash> is a precomputed hash of the key
3360 string, or zero if it has not been precomputed. Returns a mortal scalar
3361 representing the value associated with the key, or C<&PL_sv_placeholder>
3362 if there is no value associated with the key.
3368 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3369 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3372 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3374 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3375 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %" UVxf,
3379 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3380 /* For searching purposes, canonicalise to Latin-1 where possible. */
3381 const char *keyend = keypv + keylen, *p;
3382 STRLEN nonascii_count = 0;
3383 for (p = keypv; p != keyend; p++) {
3384 if (! UTF8_IS_INVARIANT(*p)) {
3385 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3386 goto canonicalised_key;
3392 if (nonascii_count) {
3394 const char *p = keypv, *keyend = keypv + keylen;
3395 keylen -= nonascii_count;
3396 Newx(q, keylen, char);
3399 for (; p != keyend; p++, q++) {
3401 if (UTF8_IS_INVARIANT(c)) {
3406 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3410 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3411 canonicalised_key: ;
3413 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3415 PERL_HASH(hash, keypv, keylen);
3417 for (; chain; chain = chain->refcounted_he_next) {
3420 hash == chain->refcounted_he_hash &&
3421 keylen == chain->refcounted_he_keylen &&
3422 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3423 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3425 hash == HEK_HASH(chain->refcounted_he_hek) &&
3426 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3427 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3428 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3431 if (flags & REFCOUNTED_HE_EXISTS)
3432 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3434 ? NULL : &PL_sv_yes;
3435 return sv_2mortal(refcounted_he_value(chain));
3439 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3443 =for apidoc refcounted_he_fetch_pv
3445 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3446 instead of a string/length pair.
3452 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3453 const char *key, U32 hash, U32 flags)
3455 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3456 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3460 =for apidoc refcounted_he_fetch_sv
3462 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3469 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3470 SV *key, U32 hash, U32 flags)
3474 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3475 if (flags & REFCOUNTED_HE_KEY_UTF8)
3476 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %" UVxf,
3478 keypv = SvPV_const(key, keylen);
3480 flags |= REFCOUNTED_HE_KEY_UTF8;
3481 if (!hash && SvIsCOW_shared_hash(key))
3482 hash = SvSHARED_HASH(key);
3483 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3487 =for apidoc refcounted_he_new_pvn
3489 Creates a new C<refcounted_he>. This consists of a single key/value
3490 pair and a reference to an existing C<refcounted_he> chain (which may
3491 be empty), and thus forms a longer chain. When using the longer chain,
3492 the new key/value pair takes precedence over any entry for the same key
3493 further along the chain.
3495 The new key is specified by C<keypv> and C<keylen>. If C<flags> has
3496 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3497 as UTF-8, otherwise they are interpreted as Latin-1. C<hash> is
3498 a precomputed hash of the key string, or zero if it has not been
3501 C<value> is the scalar value to store for this key. C<value> is copied
3502 by this function, which thus does not take ownership of any reference
3503 to it, and later changes to the scalar will not be reflected in the
3504 value visible in the C<refcounted_he>. Complex types of scalar will not
3505 be stored with referential integrity, but will be coerced to strings.
3506 C<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3507 value is to be associated with the key; this, as with any non-null value,
3508 takes precedence over the existence of a value for the key further along
3511 C<parent> points to the rest of the C<refcounted_he> chain to be
3512 attached to the new C<refcounted_he>. This function takes ownership
3513 of one reference to C<parent>, and returns one reference to the new
3519 struct refcounted_he *
3520 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3521 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3523 STRLEN value_len = 0;
3524 const char *value_p = NULL;
3528 STRLEN key_offset = 1;
3529 struct refcounted_he *he;
3530 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3532 if (!value || value == &PL_sv_placeholder) {
3533 value_type = HVrhek_delete;
3534 } else if (SvPOK(value)) {
3535 value_type = HVrhek_PV;
3536 } else if (SvIOK(value)) {
3537 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3538 } else if (!SvOK(value)) {
3539 value_type = HVrhek_undef;
3541 value_type = HVrhek_PV;
3543 is_pv = value_type == HVrhek_PV;
3545 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3546 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3547 value_p = SvPV_const(value, value_len);
3549 value_type = HVrhek_PV_UTF8;
3550 key_offset = value_len + 2;
3552 hekflags = value_type;
3554 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3555 /* Canonicalise to Latin-1 where possible. */
3556 const char *keyend = keypv + keylen, *p;
3557 STRLEN nonascii_count = 0;
3558 for (p = keypv; p != keyend; p++) {
3559 if (! UTF8_IS_INVARIANT(*p)) {
3560 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3561 goto canonicalised_key;
3567 if (nonascii_count) {
3569 const char *p = keypv, *keyend = keypv + keylen;
3570 keylen -= nonascii_count;
3571 Newx(q, keylen, char);
3574 for (; p != keyend; p++, q++) {
3576 if (UTF8_IS_INVARIANT(c)) {
3581 *q = (char) EIGHT_BIT_UTF8_TO_NATIVE(c, *p);
3585 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3586 canonicalised_key: ;
3588 if (flags & REFCOUNTED_HE_KEY_UTF8)
3589 hekflags |= HVhek_UTF8;
3591 PERL_HASH(hash, keypv, keylen);
3594 he = (struct refcounted_he*)
3595 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3599 he = (struct refcounted_he*)
3600 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3604 he->refcounted_he_next = parent;
3607 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3608 he->refcounted_he_val.refcounted_he_u_len = value_len;
3609 } else if (value_type == HVrhek_IV) {
3610 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3611 } else if (value_type == HVrhek_UV) {
3612 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3616 he->refcounted_he_hash = hash;
3617 he->refcounted_he_keylen = keylen;
3618 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3620 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3623 he->refcounted_he_data[0] = hekflags;
3624 he->refcounted_he_refcnt = 1;
3630 =for apidoc refcounted_he_new_pv
3632 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3633 of a string/length pair.
3638 struct refcounted_he *
3639 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3640 const char *key, U32 hash, SV *value, U32 flags)
3642 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3643 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3647 =for apidoc refcounted_he_new_sv
3649 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3655 struct refcounted_he *
3656 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3657 SV *key, U32 hash, SV *value, U32 flags)
3661 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3662 if (flags & REFCOUNTED_HE_KEY_UTF8)
3663 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %" UVxf,
3665 keypv = SvPV_const(key, keylen);
3667 flags |= REFCOUNTED_HE_KEY_UTF8;
3668 if (!hash && SvIsCOW_shared_hash(key))
3669 hash = SvSHARED_HASH(key);
3670 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3674 =for apidoc refcounted_he_free
3676 Decrements the reference count of a C<refcounted_he> by one. If the
3677 reference count reaches zero the structure's memory is freed, which
3678 (recursively) causes a reduction of its parent C<refcounted_he>'s
3679 reference count. It is safe to pass a null pointer to this function:
3680 no action occurs in this case.
3686 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3687 PERL_UNUSED_CONTEXT;
3690 struct refcounted_he *copy;
3694 new_count = --he->refcounted_he_refcnt;
3695 HINTS_REFCNT_UNLOCK;
3701 #ifndef USE_ITHREADS
3702 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3705 he = he->refcounted_he_next;
3706 PerlMemShared_free(copy);
3711 =for apidoc refcounted_he_inc
3713 Increment the reference count of a C<refcounted_he>. The pointer to the
3714 C<refcounted_he> is also returned. It is safe to pass a null pointer
3715 to this function: no action occurs and a null pointer is returned.
3720 struct refcounted_he *
3721 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3723 PERL_UNUSED_CONTEXT;
3726 he->refcounted_he_refcnt++;
3727 HINTS_REFCNT_UNLOCK;
3733 =for apidoc_section $COP
3734 =for apidoc cop_fetch_label
3736 Returns the label attached to a cop, and stores its length in bytes into
3738 Upon return, C<*flags> will be set to either C<SVf_UTF8> or 0.
3740 Alternatively, use the macro C<L</CopLABEL_len_flags>>;
3741 or if you don't need to know if the label is UTF-8 or not, the macro
3742 C<L</CopLABEL_len>>;
3743 or if you additionally dont need to know the length, C<L</CopLABEL>>.
3748 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3751 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3752 struct refcounted_he *const chain = cop->cop_hints_hash;
3754 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3755 PERL_UNUSED_CONTEXT;
3760 if (chain->refcounted_he_keylen != 1)
3762 if (*REF_HE_KEY(chain) != ':')
3765 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3767 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3770 /* Stop anyone trying to really mess us up by adding their own value for
3772 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3773 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3777 *len = chain->refcounted_he_val.refcounted_he_u_len;
3779 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3780 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3782 return chain->refcounted_he_data + 1;
3786 =for apidoc cop_store_label
3788 Save a label into a C<cop_hints_hash>.
3789 You need to set flags to C<SVf_UTF8>
3790 for a UTF-8 label. Any other flag is ignored.
3796 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3800 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3802 if (flags & ~(SVf_UTF8))
3803 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3805 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3806 if (flags & SVf_UTF8)
3809 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3813 =for apidoc_section $HV
3814 =for apidoc hv_assert
3816 Check that a hash is in an internally consistent state.
3824 Perl_hv_assert(pTHX_ HV *hv)
3828 int placeholders = 0;
3831 const I32 riter = HvRITER_get(hv);
3832 HE *eiter = HvEITER_get(hv);
3834 PERL_ARGS_ASSERT_HV_ASSERT;
3836 (void)hv_iterinit(hv);
3838 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3839 /* sanity check the values */
3840 if (HeVAL(entry) == &PL_sv_placeholder)
3844 /* sanity check the keys */
3845 if (HeSVKEY(entry)) {
3846 NOOP; /* Don't know what to check on SV keys. */
3847 } else if (HeKUTF8(entry)) {
3849 if (HeKWASUTF8(entry)) {
3850 PerlIO_printf(Perl_debug_log,
3851 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3852 (int) HeKLEN(entry), HeKEY(entry));
3855 } else if (HeKWASUTF8(entry))
3858 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3859 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3860 const int nhashkeys = HvUSEDKEYS(hv);
3861 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3863 if (nhashkeys != real) {
3864 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3867 if (nhashplaceholders != placeholders) {
3868 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3872 if (withflags && ! HvHASKFLAGS(hv)) {
3873 PerlIO_printf(Perl_debug_log,
3874 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3879 sv_dump(MUTABLE_SV(hv));
3881 HvRITER_set(hv, riter); /* Restore hash iterator state */
3882 HvEITER_set(hv, eiter);
3888 * ex: set ts=8 sts=4 sw=4 et: