3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
22 A HV structure represents a Perl hash. It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures. The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value. Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
35 #define PERL_HASH_INTERNAL_ACCESS
38 #define DO_HSPLIT(xhv) ((xhv)->xhv_keys > (xhv)->xhv_max) /* HvTOTALKEYS(hv) > HvMAX(hv) */
39 #define HV_FILL_THRESHOLD 31
41 static const char S_strtab_error[]
42 = "Cannot modify shared string table in hv_%s";
46 #define new_HE() (HE*)safemalloc(sizeof(HE))
47 #define del_HE(p) safefree((char*)p)
56 void ** const root = &PL_body_roots[HE_SVSLOT];
59 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
66 #define new_HE() new_he()
69 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
70 PL_body_roots[HE_SVSLOT] = p; \
78 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
80 const int flags_masked = flags & HVhek_MASK;
84 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
86 Newx(k, HEK_BASESIZE + len + 2, char);
88 Copy(str, HEK_KEY(hek), len, char);
89 HEK_KEY(hek)[len] = 0;
92 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
94 if (flags & HVhek_FREEKEY)
99 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
103 Perl_free_tied_hv_pool(pTHX)
106 HE *he = PL_hv_fetch_ent_mh;
109 Safefree(HeKEY_hek(he));
113 PL_hv_fetch_ent_mh = NULL;
116 #if defined(USE_ITHREADS)
118 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
122 PERL_ARGS_ASSERT_HEK_DUP;
123 PERL_UNUSED_ARG(param);
128 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
130 /* We already shared this hash key. */
131 (void)share_hek_hek(shared);
135 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
136 HEK_HASH(source), HEK_FLAGS(source));
137 ptr_table_store(PL_ptr_table, source, shared);
143 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
147 PERL_ARGS_ASSERT_HE_DUP;
151 /* look for it in the table first */
152 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
156 /* create anew and remember what it is */
158 ptr_table_store(PL_ptr_table, e, ret);
160 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
161 if (HeKLEN(e) == HEf_SVKEY) {
163 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
164 HeKEY_hek(ret) = (HEK*)k;
165 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
168 /* This is hek_dup inlined, which seems to be important for speed
170 HEK * const source = HeKEY_hek(e);
171 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
174 /* We already shared this hash key. */
175 (void)share_hek_hek(shared);
179 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
180 HEK_HASH(source), HEK_FLAGS(source));
181 ptr_table_store(PL_ptr_table, source, shared);
183 HeKEY_hek(ret) = shared;
186 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
188 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
191 #endif /* USE_ITHREADS */
194 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
197 SV * const sv = sv_newmortal();
199 PERL_ARGS_ASSERT_HV_NOTALLOWED;
201 if (!(flags & HVhek_FREEKEY)) {
202 sv_setpvn(sv, key, klen);
205 /* Need to free saved eventually assign to mortal SV */
206 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
207 sv_usepvn(sv, (char *) key, klen);
209 if (flags & HVhek_UTF8) {
212 Perl_croak(aTHX_ msg, SVfARG(sv));
215 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
221 Stores an SV in a hash. The hash key is specified as C<key> and the
222 absolute value of C<klen> is the length of the key. If C<klen> is
223 negative the key is assumed to be in UTF-8-encoded Unicode. The
224 C<hash> parameter is the precomputed hash value; if it is zero then
225 Perl will compute it.
227 The return value will be
228 NULL if the operation failed or if the value did not need to be actually
229 stored within the hash (as in the case of tied hashes). Otherwise it can
230 be dereferenced to get the original C<SV*>. Note that the caller is
231 responsible for suitably incrementing the reference count of C<val> before
232 the call, and decrementing it if the function returned NULL. Effectively
233 a successful hv_store takes ownership of one reference to C<val>. This is
234 usually what you want; a newly created SV has a reference count of one, so
235 if all your code does is create SVs then store them in a hash, hv_store
236 will own the only reference to the new SV, and your code doesn't need to do
237 anything further to tidy up. hv_store is not implemented as a call to
238 hv_store_ent, and does not create a temporary SV for the key, so if your
239 key data is not already in SV form then use hv_store in preference to
242 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
243 information on how to use this function on tied hashes.
245 =for apidoc hv_store_ent
247 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
248 parameter is the precomputed hash value; if it is zero then Perl will
249 compute it. The return value is the new hash entry so created. It will be
250 NULL if the operation failed or if the value did not need to be actually
251 stored within the hash (as in the case of tied hashes). Otherwise the
252 contents of the return value can be accessed using the C<He?> macros
253 described here. Note that the caller is responsible for suitably
254 incrementing the reference count of C<val> before the call, and
255 decrementing it if the function returned NULL. Effectively a successful
256 hv_store_ent takes ownership of one reference to C<val>. This is
257 usually what you want; a newly created SV has a reference count of one, so
258 if all your code does is create SVs then store them in a hash, hv_store
259 will own the only reference to the new SV, and your code doesn't need to do
260 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
261 unlike C<val> it does not take ownership of it, so maintaining the correct
262 reference count on C<key> is entirely the caller's responsibility. hv_store
263 is not implemented as a call to hv_store_ent, and does not create a temporary
264 SV for the key, so if your key data is not already in SV form then use
265 hv_store in preference to hv_store_ent.
267 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
268 information on how to use this function on tied hashes.
270 =for apidoc hv_exists
272 Returns a boolean indicating whether the specified hash key exists. The
273 absolute value of C<klen> is the length of the key. If C<klen> is
274 negative the key is assumed to be in UTF-8-encoded Unicode.
278 Returns the SV which corresponds to the specified key in the hash.
279 The absolute value of C<klen> is the length of the key. If C<klen> is
280 negative the key is assumed to be in UTF-8-encoded Unicode. If
281 C<lval> is set then the fetch will be part of a store. This means that if
282 there is no value in the hash associated with the given key, then one is
283 created and a pointer to it is returned. The C<SV*> it points to can be
284 assigned to. But always check that the
285 return value is non-null before dereferencing it to an C<SV*>.
287 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
288 information on how to use this function on tied hashes.
290 =for apidoc hv_exists_ent
292 Returns a boolean indicating whether
293 the specified hash key exists. C<hash>
294 can be a valid precomputed hash value, or 0 to ask for it to be
300 /* returns an HE * structure with the all fields set */
301 /* note that hent_val will be a mortal sv for MAGICAL hashes */
303 =for apidoc hv_fetch_ent
305 Returns the hash entry which corresponds to the specified key in the hash.
306 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
307 if you want the function to compute it. IF C<lval> is set then the fetch
308 will be part of a store. Make sure the return value is non-null before
309 accessing it. The return value when C<hv> is a tied hash is a pointer to a
310 static location, so be sure to make a copy of the structure if you need to
313 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
314 information on how to use this function on tied hashes.
319 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
321 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
322 const int action, SV *val, const U32 hash)
327 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
336 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
340 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
341 int flags, int action, SV *val, U32 hash)
350 const int return_svp = action & HV_FETCH_JUST_SV;
354 if (SvTYPE(hv) == (svtype)SVTYPEMASK)
357 assert(SvTYPE(hv) == SVt_PVHV);
359 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
361 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
362 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
363 if (uf->uf_set == NULL) {
364 SV* obj = mg->mg_obj;
367 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
368 ((flags & HVhek_UTF8)
372 mg->mg_obj = keysv; /* pass key */
373 uf->uf_index = action; /* pass action */
374 magic_getuvar(MUTABLE_SV(hv), mg);
375 keysv = mg->mg_obj; /* may have changed */
378 /* If the key may have changed, then we need to invalidate
379 any passed-in computed hash value. */
385 if (flags & HVhek_FREEKEY)
387 key = SvPV_const(keysv, klen);
388 is_utf8 = (SvUTF8(keysv) != 0);
389 if (SvIsCOW_shared_hash(keysv)) {
390 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
392 flags = is_utf8 ? HVhek_UTF8 : 0;
395 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
398 if (action & HV_DELETE) {
399 return (void *) hv_delete_common(hv, keysv, key, klen,
400 flags, action, hash);
403 xhv = (XPVHV*)SvANY(hv);
405 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
406 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
407 || SvGMAGICAL((const SV *)hv))
409 /* FIXME should be able to skimp on the HE/HEK here when
410 HV_FETCH_JUST_SV is true. */
412 keysv = newSVpvn_utf8(key, klen, is_utf8);
414 keysv = newSVsv(keysv);
417 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
419 /* grab a fake HE/HEK pair from the pool or make a new one */
420 entry = PL_hv_fetch_ent_mh;
422 PL_hv_fetch_ent_mh = HeNEXT(entry);
426 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
427 HeKEY_hek(entry) = (HEK*)k;
429 HeNEXT(entry) = NULL;
430 HeSVKEY_set(entry, keysv);
432 sv_upgrade(sv, SVt_PVLV);
434 /* so we can free entry when freeing sv */
435 LvTARG(sv) = MUTABLE_SV(entry);
437 /* XXX remove at some point? */
438 if (flags & HVhek_FREEKEY)
442 return entry ? (void *) &HeVAL(entry) : NULL;
444 return (void *) entry;
446 #ifdef ENV_IS_CASELESS
447 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
449 for (i = 0; i < klen; ++i)
450 if (isLOWER(key[i])) {
451 /* Would be nice if we had a routine to do the
452 copy and upercase in a single pass through. */
453 const char * const nkey = strupr(savepvn(key,klen));
454 /* Note that this fetch is for nkey (the uppercased
455 key) whereas the store is for key (the original) */
456 void *result = hv_common(hv, NULL, nkey, klen,
457 HVhek_FREEKEY, /* free nkey */
458 0 /* non-LVAL fetch */
459 | HV_DISABLE_UVAR_XKEY
462 0 /* compute hash */);
463 if (!result && (action & HV_FETCH_LVALUE)) {
464 /* This call will free key if necessary.
465 Do it this way to encourage compiler to tail
467 result = hv_common(hv, keysv, key, klen, flags,
469 | HV_DISABLE_UVAR_XKEY
473 if (flags & HVhek_FREEKEY)
481 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
482 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
483 || SvGMAGICAL((const SV *)hv)) {
484 /* I don't understand why hv_exists_ent has svret and sv,
485 whereas hv_exists only had one. */
486 SV * const svret = sv_newmortal();
489 if (keysv || is_utf8) {
491 keysv = newSVpvn_utf8(key, klen, TRUE);
493 keysv = newSVsv(keysv);
495 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
497 mg_copy(MUTABLE_SV(hv), sv, key, klen);
499 if (flags & HVhek_FREEKEY)
501 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
502 /* This cast somewhat evil, but I'm merely using NULL/
503 not NULL to return the boolean exists.
504 And I know hv is not NULL. */
505 return SvTRUE(svret) ? (void *)hv : NULL;
507 #ifdef ENV_IS_CASELESS
508 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
509 /* XXX This code isn't UTF8 clean. */
510 char * const keysave = (char * const)key;
511 /* Will need to free this, so set FREEKEY flag. */
512 key = savepvn(key,klen);
513 key = (const char*)strupr((char*)key);
518 if (flags & HVhek_FREEKEY) {
521 flags |= HVhek_FREEKEY;
525 else if (action & HV_FETCH_ISSTORE) {
528 hv_magic_check (hv, &needs_copy, &needs_store);
530 const bool save_taint = TAINT_get;
531 if (keysv || is_utf8) {
533 keysv = newSVpvn_utf8(key, klen, TRUE);
536 TAINT_set(SvTAINTED(keysv));
537 keysv = sv_2mortal(newSVsv(keysv));
538 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
540 mg_copy(MUTABLE_SV(hv), val, key, klen);
543 TAINT_IF(save_taint);
544 #ifdef NO_TAINT_SUPPORT
545 PERL_UNUSED_VAR(save_taint);
548 if (flags & HVhek_FREEKEY)
552 #ifdef ENV_IS_CASELESS
553 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
554 /* XXX This code isn't UTF8 clean. */
555 const char *keysave = key;
556 /* Will need to free this, so set FREEKEY flag. */
557 key = savepvn(key,klen);
558 key = (const char*)strupr((char*)key);
563 if (flags & HVhek_FREEKEY) {
566 flags |= HVhek_FREEKEY;
574 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
575 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
576 || (SvRMAGICAL((const SV *)hv)
577 && mg_find((const SV *)hv, PERL_MAGIC_env))
582 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
584 HvARRAY(hv) = (HE**)array;
586 #ifdef DYNAMIC_ENV_FETCH
587 else if (action & HV_FETCH_ISEXISTS) {
588 /* for an %ENV exists, if we do an insert it's by a recursive
589 store call, so avoid creating HvARRAY(hv) right now. */
593 /* XXX remove at some point? */
594 if (flags & HVhek_FREEKEY)
601 if (is_utf8 && !(flags & HVhek_KEYCANONICAL)) {
602 char * const keysave = (char *)key;
603 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
607 flags &= ~HVhek_UTF8;
608 if (key != keysave) {
609 if (flags & HVhek_FREEKEY)
611 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
612 /* If the caller calculated a hash, it was on the sequence of
613 octets that are the UTF-8 form. We've now changed the sequence
614 of octets stored to that of the equivalent byte representation,
615 so the hash we need is different. */
621 if (keysv && (SvIsCOW_shared_hash(keysv)))
622 hash = SvSHARED_HASH(keysv);
624 PERL_HASH(hash, key, klen);
627 masked_flags = (flags & HVhek_MASK);
629 #ifdef DYNAMIC_ENV_FETCH
630 if (!HvARRAY(hv)) entry = NULL;
634 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
636 for (; entry; entry = HeNEXT(entry)) {
637 if (HeHASH(entry) != hash) /* strings can't be equal */
639 if (HeKLEN(entry) != (I32)klen)
641 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
643 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
646 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
647 if (HeKFLAGS(entry) != masked_flags) {
648 /* We match if HVhek_UTF8 bit in our flags and hash key's
649 match. But if entry was set previously with HVhek_WASUTF8
650 and key now doesn't (or vice versa) then we should change
651 the key's flag, as this is assignment. */
652 if (HvSHAREKEYS(hv)) {
653 /* Need to swap the key we have for a key with the flags we
654 need. As keys are shared we can't just write to the
655 flag, so we share the new one, unshare the old one. */
656 HEK * const new_hek = share_hek_flags(key, klen, hash,
658 unshare_hek (HeKEY_hek(entry));
659 HeKEY_hek(entry) = new_hek;
661 else if (hv == PL_strtab) {
662 /* PL_strtab is usually the only hash without HvSHAREKEYS,
663 so putting this test here is cheap */
664 if (flags & HVhek_FREEKEY)
666 Perl_croak(aTHX_ S_strtab_error,
667 action & HV_FETCH_LVALUE ? "fetch" : "store");
670 HeKFLAGS(entry) = masked_flags;
671 if (masked_flags & HVhek_ENABLEHVKFLAGS)
674 if (HeVAL(entry) == &PL_sv_placeholder) {
675 /* yes, can store into placeholder slot */
676 if (action & HV_FETCH_LVALUE) {
678 /* This preserves behaviour with the old hv_fetch
679 implementation which at this point would bail out
680 with a break; (at "if we find a placeholder, we
681 pretend we haven't found anything")
683 That break mean that if a placeholder were found, it
684 caused a call into hv_store, which in turn would
685 check magic, and if there is no magic end up pretty
686 much back at this point (in hv_store's code). */
689 /* LVAL fetch which actually needs a store. */
691 HvPLACEHOLDERS(hv)--;
694 if (val != &PL_sv_placeholder)
695 HvPLACEHOLDERS(hv)--;
698 } else if (action & HV_FETCH_ISSTORE) {
699 SvREFCNT_dec(HeVAL(entry));
702 } else if (HeVAL(entry) == &PL_sv_placeholder) {
703 /* if we find a placeholder, we pretend we haven't found
707 if (flags & HVhek_FREEKEY)
710 return entry ? (void *) &HeVAL(entry) : NULL;
714 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
715 if (!(action & HV_FETCH_ISSTORE)
716 && SvRMAGICAL((const SV *)hv)
717 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
719 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
721 sv = newSVpvn(env,len);
723 return hv_common(hv, keysv, key, klen, flags,
724 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
730 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
731 hv_notallowed(flags, key, klen,
732 "Attempt to access disallowed key '%"SVf"' in"
733 " a restricted hash");
735 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
736 /* Not doing some form of store, so return failure. */
737 if (flags & HVhek_FREEKEY)
741 if (action & HV_FETCH_LVALUE) {
742 val = action & HV_FETCH_EMPTY_HE ? NULL : newSV(0);
744 /* At this point the old hv_fetch code would call to hv_store,
745 which in turn might do some tied magic. So we need to make that
746 magic check happen. */
747 /* gonna assign to this, so it better be there */
748 /* If a fetch-as-store fails on the fetch, then the action is to
749 recurse once into "hv_store". If we didn't do this, then that
750 recursive call would call the key conversion routine again.
751 However, as we replace the original key with the converted
752 key, this would result in a double conversion, which would show
753 up as a bug if the conversion routine is not idempotent.
754 Hence the use of HV_DISABLE_UVAR_XKEY. */
755 return hv_common(hv, keysv, key, klen, flags,
756 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
758 /* XXX Surely that could leak if the fetch-was-store fails?
759 Just like the hv_fetch. */
763 /* Welcome to hv_store... */
766 /* Not sure if we can get here. I think the only case of oentry being
767 NULL is for %ENV with dynamic env fetch. But that should disappear
768 with magic in the previous code. */
771 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
773 HvARRAY(hv) = (HE**)array;
776 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
779 /* share_hek_flags will do the free for us. This might be considered
782 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
783 else if (hv == PL_strtab) {
784 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
785 this test here is cheap */
786 if (flags & HVhek_FREEKEY)
788 Perl_croak(aTHX_ S_strtab_error,
789 action & HV_FETCH_LVALUE ? "fetch" : "store");
791 else /* gotta do the real thing */
792 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
795 if (!*oentry && SvOOK(hv)) {
796 /* initial entry, and aux struct present. */
797 struct xpvhv_aux *const aux = HvAUX(hv);
798 if (aux->xhv_fill_lazy)
799 ++aux->xhv_fill_lazy;
802 #ifdef PERL_HASH_RANDOMIZE_KEYS
803 /* This logic semi-randomizes the insert order in a bucket.
804 * Either we insert into the top, or the slot below the top,
805 * making it harder to see if there is a collision. We also
806 * reset the iterator randomizer if there is one.
808 if ( *oentry && PL_HASH_RAND_BITS_ENABLED) {
810 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
811 if ( PL_hash_rand_bits & 1 ) {
812 HeNEXT(entry) = HeNEXT(*oentry);
813 HeNEXT(*oentry) = entry;
815 HeNEXT(entry) = *oentry;
821 HeNEXT(entry) = *oentry;
824 #ifdef PERL_HASH_RANDOMIZE_KEYS
826 /* Currently this makes various tests warn in annoying ways.
827 * So Silenced for now. - Yves | bogus end of comment =>* /
828 if (HvAUX(hv)->xhv_riter != -1) {
829 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
830 "[TESTING] Inserting into a hash during each() traversal results in undefined behavior"
835 if (PL_HASH_RAND_BITS_ENABLED) {
836 if (PL_HASH_RAND_BITS_ENABLED == 1)
837 PL_hash_rand_bits += (PTRV)entry + 1; /* we don't bother to use ptr_hash here */
838 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
840 HvAUX(hv)->xhv_rand= (U32)PL_hash_rand_bits;
844 if (val == &PL_sv_placeholder)
845 HvPLACEHOLDERS(hv)++;
846 if (masked_flags & HVhek_ENABLEHVKFLAGS)
849 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
850 if ( DO_HSPLIT(xhv) ) {
851 const STRLEN oldsize = xhv->xhv_max + 1;
852 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
854 if (items /* hash has placeholders */
855 && !SvREADONLY(hv) /* but is not a restricted hash */) {
856 /* If this hash previously was a "restricted hash" and had
857 placeholders, but the "restricted" flag has been turned off,
858 then the placeholders no longer serve any useful purpose.
859 However, they have the downsides of taking up RAM, and adding
860 extra steps when finding used values. It's safe to clear them
861 at this point, even though Storable rebuilds restricted hashes by
862 putting in all the placeholders (first) before turning on the
863 readonly flag, because Storable always pre-splits the hash.
864 If we're lucky, then we may clear sufficient placeholders to
865 avoid needing to split the hash at all. */
866 clear_placeholders(hv, items);
868 hsplit(hv, oldsize, oldsize * 2);
870 hsplit(hv, oldsize, oldsize * 2);
874 return entry ? (void *) &HeVAL(entry) : NULL;
876 return (void *) entry;
880 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
882 const MAGIC *mg = SvMAGIC(hv);
884 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
889 if (isUPPER(mg->mg_type)) {
891 if (mg->mg_type == PERL_MAGIC_tied) {
892 *needs_store = FALSE;
893 return; /* We've set all there is to set. */
896 mg = mg->mg_moremagic;
901 =for apidoc hv_scalar
903 Evaluates the hash in scalar context and returns the result. Handles magic
904 when the hash is tied.
910 Perl_hv_scalar(pTHX_ HV *hv)
914 PERL_ARGS_ASSERT_HV_SCALAR;
916 if (SvRMAGICAL(hv)) {
917 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
919 return magic_scalarpack(hv, mg);
923 if (HvTOTALKEYS((const HV *)hv))
924 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
925 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
933 =for apidoc hv_delete
935 Deletes a key/value pair in the hash. The value's SV is removed from
936 the hash, made mortal, and returned to the caller. The absolute
937 value of C<klen> is the length of the key. If C<klen> is negative the
938 key is assumed to be in UTF-8-encoded Unicode. The C<flags> value
939 will normally be zero; if set to G_DISCARD then NULL will be returned.
940 NULL will also be returned if the key is not found.
942 =for apidoc hv_delete_ent
944 Deletes a key/value pair in the hash. The value SV is removed from the hash,
945 made mortal, and returned to the caller. The C<flags> value will normally be
946 zero; if set to G_DISCARD then NULL will be returned. NULL will also be
947 returned if the key is not found. C<hash> can be a valid precomputed hash
948 value, or 0 to ask for it to be computed.
954 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
955 int k_flags, I32 d_flags, U32 hash)
961 HE *const *first_entry;
962 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
965 if (SvRMAGICAL(hv)) {
968 hv_magic_check (hv, &needs_copy, &needs_store);
972 entry = (HE *) hv_common(hv, keysv, key, klen,
973 k_flags & ~HVhek_FREEKEY,
974 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
976 sv = entry ? HeVAL(entry) : NULL;
982 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
983 /* No longer an element */
984 sv_unmagic(sv, PERL_MAGIC_tiedelem);
987 return NULL; /* element cannot be deleted */
989 #ifdef ENV_IS_CASELESS
990 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
991 /* XXX This code isn't UTF8 clean. */
992 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
993 if (k_flags & HVhek_FREEKEY) {
996 key = strupr(SvPVX(keysv));
1005 xhv = (XPVHV*)SvANY(hv);
1009 if (is_utf8 && !(k_flags & HVhek_KEYCANONICAL)) {
1010 const char * const keysave = key;
1011 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
1014 k_flags |= HVhek_UTF8;
1016 k_flags &= ~HVhek_UTF8;
1017 if (key != keysave) {
1018 if (k_flags & HVhek_FREEKEY) {
1019 /* This shouldn't happen if our caller does what we expect,
1020 but strictly the API allows it. */
1023 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
1025 HvHASKFLAGS_on(MUTABLE_SV(hv));
1029 if (keysv && (SvIsCOW_shared_hash(keysv)))
1030 hash = SvSHARED_HASH(keysv);
1032 PERL_HASH(hash, key, klen);
1035 masked_flags = (k_flags & HVhek_MASK);
1037 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1039 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1041 U8 mro_changes = 0; /* 1 = isa; 2 = package moved */
1045 if (HeHASH(entry) != hash) /* strings can't be equal */
1047 if (HeKLEN(entry) != (I32)klen)
1049 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1051 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1054 if (hv == PL_strtab) {
1055 if (k_flags & HVhek_FREEKEY)
1057 Perl_croak(aTHX_ S_strtab_error, "delete");
1060 /* if placeholder is here, it's already been deleted.... */
1061 if (HeVAL(entry) == &PL_sv_placeholder) {
1062 if (k_flags & HVhek_FREEKEY)
1066 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1067 hv_notallowed(k_flags, key, klen,
1068 "Attempt to delete readonly key '%"SVf"' from"
1069 " a restricted hash");
1071 if (k_flags & HVhek_FREEKEY)
1074 /* If this is a stash and the key ends with ::, then someone is
1075 * deleting a package.
1077 if (HeVAL(entry) && HvENAME_get(hv)) {
1078 gv = (GV *)HeVAL(entry);
1079 if (keysv) key = SvPV(keysv, klen);
1081 (klen > 1 && key[klen-2] == ':' && key[klen-1] == ':')
1083 (klen == 1 && key[0] == ':')
1085 && (klen != 6 || hv!=PL_defstash || memNE(key,"main::",6))
1086 && SvTYPE(gv) == SVt_PVGV && (stash = GvHV((GV *)gv))
1087 && HvENAME_get(stash)) {
1088 /* A previous version of this code checked that the
1089 * GV was still in the symbol table by fetching the
1090 * GV with its name. That is not necessary (and
1091 * sometimes incorrect), as HvENAME cannot be set
1092 * on hv if it is not in the symtab. */
1094 /* Hang on to it for a bit. */
1095 SvREFCNT_inc_simple_void_NN(
1096 sv_2mortal((SV *)gv)
1099 else if (klen == 3 && strnEQ(key, "ISA", 3))
1103 sv = d_flags & G_DISCARD ? HeVAL(entry) : sv_2mortal(HeVAL(entry));
1104 HeVAL(entry) = &PL_sv_placeholder;
1106 /* deletion of method from stash */
1107 if (isGV(sv) && isGV_with_GP(sv) && GvCVu(sv)
1109 mro_method_changed_in(hv);
1113 * If a restricted hash, rather than really deleting the entry, put
1114 * a placeholder there. This marks the key as being "approved", so
1115 * we can still access via not-really-existing key without raising
1119 /* We'll be saving this slot, so the number of allocated keys
1120 * doesn't go down, but the number placeholders goes up */
1121 HvPLACEHOLDERS(hv)++;
1123 *oentry = HeNEXT(entry);
1124 if(!*first_entry && SvOOK(hv)) {
1125 /* removed last entry, and aux struct present. */
1126 struct xpvhv_aux *const aux = HvAUX(hv);
1127 if (aux->xhv_fill_lazy)
1128 --aux->xhv_fill_lazy;
1130 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1133 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1134 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1135 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1136 hv_free_ent(hv, entry);
1138 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1139 if (xhv->xhv_keys == 0)
1140 HvHASKFLAGS_off(hv);
1143 if (d_flags & G_DISCARD) {
1148 if (mro_changes == 1) mro_isa_changed_in(hv);
1149 else if (mro_changes == 2)
1150 mro_package_moved(NULL, stash, gv, 1);
1154 if (SvREADONLY(hv)) {
1155 hv_notallowed(k_flags, key, klen,
1156 "Attempt to delete disallowed key '%"SVf"' from"
1157 " a restricted hash");
1160 if (k_flags & HVhek_FREEKEY)
1167 S_hsplit(pTHX_ HV *hv, STRLEN const oldsize, STRLEN newsize)
1171 char *a = (char*) HvARRAY(hv);
1175 /* already have an HvAUX(hv) so we have to move it */
1177 /* no HvAUX() but array we are going to allocate is large enough
1178 * there is no point in saving the space for the iterator, and
1179 * speeds up later traversals. */
1180 ( ( hv != PL_strtab ) && ( newsize >= PERL_HV_ALLOC_AUX_SIZE ) )
1183 PERL_ARGS_ASSERT_HSPLIT;
1186 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1187 + (do_aux ? sizeof(struct xpvhv_aux) : 0), char);
1193 #ifdef PERL_HASH_RANDOMIZE_KEYS
1194 /* the idea of this is that we create a "random" value by hashing the address of
1195 * the array, we then use the low bit to decide if we insert at the top, or insert
1196 * second from top. After each such insert we rotate the hashed value. So we can
1197 * use the same hashed value over and over, and in normal build environments use
1198 * very few ops to do so. ROTL32() should produce a single machine operation. */
1199 if (PL_HASH_RAND_BITS_ENABLED) {
1200 if (PL_HASH_RAND_BITS_ENABLED == 1)
1201 PL_hash_rand_bits += ptr_hash((PTRV)a);
1202 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
1205 HvARRAY(hv) = (HE**) a;
1206 HvMAX(hv) = newsize - 1;
1207 /* before we zero the newly added memory, we
1208 * need to deal with the aux struct that may be there
1209 * or have been allocated by us*/
1211 struct xpvhv_aux *const dest
1212 = (struct xpvhv_aux*) &a[newsize * sizeof(HE*)];
1214 /* alread have an aux, copy the old one in place. */
1215 Move(&a[oldsize * sizeof(HE*)], dest, 1, struct xpvhv_aux);
1216 /* we reset the iterator's xhv_rand as well, so they get a totally new ordering */
1217 #ifdef PERL_HASH_RANDOMIZE_KEYS
1218 dest->xhv_rand = (U32)PL_hash_rand_bits;
1220 /* For now, just reset the lazy fill counter.
1221 It would be possible to update the counter in the code below
1223 dest->xhv_fill_lazy = 0;
1225 /* no existing aux structure, but we allocated space for one
1226 * so intialize it properly. This unrolls hv_auxinit() a bit,
1227 * since we have to do the realloc anyway. */
1228 /* first we set the iterator's xhv_rand so it can be copied into lastrand below */
1229 #ifdef PERL_HASH_RANDOMIZE_KEYS
1230 dest->xhv_rand = (U32)PL_hash_rand_bits;
1232 /* this is the "non realloc" part of the hv_auxinit() */
1233 (void)hv_auxinit_internal(dest);
1234 /* Turn on the OOK flag */
1238 /* now we can safely clear the second half */
1239 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1241 if (!HvTOTALKEYS(hv)) /* skip rest if no entries */
1247 HE **oentry = aep + i;
1250 if (!entry) /* non-existent */
1253 U32 j = (HeHASH(entry) & newsize);
1255 *oentry = HeNEXT(entry);
1256 #ifdef PERL_HASH_RANDOMIZE_KEYS
1257 /* if the target cell is empty or PL_HASH_RAND_BITS_ENABLED is false
1258 * insert to top, otherwise rotate the bucket rand 1 bit,
1259 * and use the new low bit to decide if we insert at top,
1260 * or next from top. IOW, we only rotate on a collision.*/
1261 if (aep[j] && PL_HASH_RAND_BITS_ENABLED) {
1262 PL_hash_rand_bits+= ROTL32(HeHASH(entry), 17);
1263 PL_hash_rand_bits= ROTL_UV(PL_hash_rand_bits,1);
1264 if (PL_hash_rand_bits & 1) {
1265 HeNEXT(entry)= HeNEXT(aep[j]);
1266 HeNEXT(aep[j])= entry;
1268 /* Note, this is structured in such a way as the optimizer
1269 * should eliminate the duplicated code here and below without
1270 * us needing to explicitly use a goto. */
1271 HeNEXT(entry) = aep[j];
1277 /* see comment above about duplicated code */
1278 HeNEXT(entry) = aep[j];
1283 oentry = &HeNEXT(entry);
1287 } while (i++ < oldsize);
1291 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1294 XPVHV* xhv = (XPVHV*)SvANY(hv);
1295 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1299 PERL_ARGS_ASSERT_HV_KSPLIT;
1301 newsize = (I32) newmax; /* possible truncation here */
1302 if (newsize != newmax || newmax <= oldsize)
1304 while ((newsize & (1 + ~newsize)) != newsize) {
1305 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1307 if (newsize < newmax)
1309 if (newsize < newmax)
1310 return; /* overflow detection */
1312 a = (char *) HvARRAY(hv);
1314 hsplit(hv, oldsize, newsize);
1316 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1317 xhv->xhv_max = --newsize;
1318 HvARRAY(hv) = (HE **) a;
1322 /* IMO this should also handle cases where hv_max is smaller than hv_keys
1323 * as tied hashes could play silly buggers and mess us around. We will
1324 * do the right thing during hv_store() afterwards, but still - Yves */
1325 #define HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys) STMT_START {\
1326 /* Can we use fewer buckets? (hv_max is always 2^n-1) */ \
1327 if (hv_max < PERL_HASH_DEFAULT_HvMAX) { \
1328 hv_max = PERL_HASH_DEFAULT_HvMAX; \
1330 while (hv_max > PERL_HASH_DEFAULT_HvMAX && hv_max + 1 >= hv_keys * 2) \
1331 hv_max = hv_max / 2; \
1333 HvMAX(hv) = hv_max; \
1338 Perl_newHVhv(pTHX_ HV *ohv)
1341 HV * const hv = newHV();
1344 if (!ohv || (!HvTOTALKEYS(ohv) && !SvMAGICAL((const SV *)ohv)))
1346 hv_max = HvMAX(ohv);
1348 if (!SvMAGICAL((const SV *)ohv)) {
1349 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1351 const bool shared = !!HvSHAREKEYS(ohv);
1352 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1354 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1357 /* In each bucket... */
1358 for (i = 0; i <= hv_max; i++) {
1360 HE *oent = oents[i];
1367 /* Copy the linked list of entries. */
1368 for (; oent; oent = HeNEXT(oent)) {
1369 const U32 hash = HeHASH(oent);
1370 const char * const key = HeKEY(oent);
1371 const STRLEN len = HeKLEN(oent);
1372 const int flags = HeKFLAGS(oent);
1373 HE * const ent = new_HE();
1374 SV *const val = HeVAL(oent);
1376 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1378 = shared ? share_hek_flags(key, len, hash, flags)
1379 : save_hek_flags(key, len, hash, flags);
1390 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1394 /* Iterate over ohv, copying keys and values one at a time. */
1396 const I32 riter = HvRITER_get(ohv);
1397 HE * const eiter = HvEITER_get(ohv);
1398 STRLEN hv_keys = HvTOTALKEYS(ohv);
1400 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1403 while ((entry = hv_iternext_flags(ohv, 0))) {
1404 SV *val = hv_iterval(ohv,entry);
1405 SV * const keysv = HeSVKEY(entry);
1406 val = SvIMMORTAL(val) ? val : newSVsv(val);
1408 (void)hv_store_ent(hv, keysv, val, 0);
1410 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry), val,
1411 HeHASH(entry), HeKFLAGS(entry));
1413 HvRITER_set(ohv, riter);
1414 HvEITER_set(ohv, eiter);
1421 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1423 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1424 a pointer to a hash (which may have C<%^H> magic, but should be generally
1425 non-magical), or C<NULL> (interpreted as an empty hash). The content
1426 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1427 added to it. A pointer to the new hash is returned.
1433 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1435 HV * const hv = newHV();
1438 STRLEN hv_max = HvMAX(ohv);
1439 STRLEN hv_keys = HvTOTALKEYS(ohv);
1441 const I32 riter = HvRITER_get(ohv);
1442 HE * const eiter = HvEITER_get(ohv);
1447 HV_SET_MAX_ADJUSTED_FOR_KEYS(hv,hv_max,hv_keys);
1450 while ((entry = hv_iternext_flags(ohv, 0))) {
1451 SV *const sv = newSVsv(hv_iterval(ohv,entry));
1452 SV *heksv = HeSVKEY(entry);
1453 if (!heksv && sv) heksv = newSVhek(HeKEY_hek(entry));
1454 if (sv) sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1455 (char *)heksv, HEf_SVKEY);
1456 if (heksv == HeSVKEY(entry))
1457 (void)hv_store_ent(hv, heksv, sv, 0);
1459 (void)hv_common(hv, heksv, HeKEY(entry), HeKLEN(entry),
1460 HeKFLAGS(entry), HV_FETCH_ISSTORE|HV_FETCH_JUST_SV, sv, HeHASH(entry));
1461 SvREFCNT_dec_NN(heksv);
1464 HvRITER_set(ohv, riter);
1465 HvEITER_set(ohv, eiter);
1467 SvREFCNT_inc_simple_void_NN(hv);
1470 hv_magic(hv, NULL, PERL_MAGIC_hints);
1473 #undef HV_SET_MAX_ADJUSTED_FOR_KEYS
1475 /* like hv_free_ent, but returns the SV rather than freeing it */
1477 S_hv_free_ent_ret(pTHX_ HV *hv, HE *entry)
1482 PERL_ARGS_ASSERT_HV_FREE_ENT_RET;
1485 if (HeKLEN(entry) == HEf_SVKEY) {
1486 SvREFCNT_dec(HeKEY_sv(entry));
1487 Safefree(HeKEY_hek(entry));
1489 else if (HvSHAREKEYS(hv))
1490 unshare_hek(HeKEY_hek(entry));
1492 Safefree(HeKEY_hek(entry));
1499 Perl_hv_free_ent(pTHX_ HV *hv, HE *entry)
1504 PERL_ARGS_ASSERT_HV_FREE_ENT;
1508 val = hv_free_ent_ret(hv, entry);
1514 Perl_hv_delayfree_ent(pTHX_ HV *hv, HE *entry)
1518 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1522 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1523 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1524 if (HeKLEN(entry) == HEf_SVKEY) {
1525 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1527 hv_free_ent(hv, entry);
1531 =for apidoc hv_clear
1533 Frees the all the elements of a hash, leaving it empty.
1534 The XS equivalent of C<%hash = ()>. See also L</hv_undef>.
1536 If any destructors are triggered as a result, the hv itself may
1543 Perl_hv_clear(pTHX_ HV *hv)
1550 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1552 xhv = (XPVHV*)SvANY(hv);
1555 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1556 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1557 /* restricted hash: convert all keys to placeholders */
1559 for (i = 0; i <= xhv->xhv_max; i++) {
1560 HE *entry = (HvARRAY(hv))[i];
1561 for (; entry; entry = HeNEXT(entry)) {
1562 /* not already placeholder */
1563 if (HeVAL(entry) != &PL_sv_placeholder) {
1565 if (SvREADONLY(HeVAL(entry))) {
1566 SV* const keysv = hv_iterkeysv(entry);
1567 Perl_croak_nocontext(
1568 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1571 SvREFCNT_dec_NN(HeVAL(entry));
1573 HeVAL(entry) = &PL_sv_placeholder;
1574 HvPLACEHOLDERS(hv)++;
1581 HvPLACEHOLDERS_set(hv, 0);
1584 mg_clear(MUTABLE_SV(hv));
1586 HvHASKFLAGS_off(hv);
1590 mro_isa_changed_in(hv);
1591 HvEITER_set(hv, NULL);
1597 =for apidoc hv_clear_placeholders
1599 Clears any placeholders from a hash. If a restricted hash has any of its keys
1600 marked as readonly and the key is subsequently deleted, the key is not actually
1601 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1602 it so it will be ignored by future operations such as iterating over the hash,
1603 but will still allow the hash to have a value reassigned to the key at some
1604 future point. This function clears any such placeholder keys from the hash.
1605 See Hash::Util::lock_keys() for an example of its use.
1611 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1614 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1616 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1619 clear_placeholders(hv, items);
1623 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1628 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1635 /* Loop down the linked list heads */
1636 HE **oentry = &(HvARRAY(hv))[i];
1639 while ((entry = *oentry)) {
1640 if (HeVAL(entry) == &PL_sv_placeholder) {
1641 *oentry = HeNEXT(entry);
1642 if (entry == HvEITER_get(hv))
1645 if (SvOOK(hv) && HvLAZYDEL(hv) &&
1646 entry == HeNEXT(HvAUX(hv)->xhv_eiter))
1647 HeNEXT(HvAUX(hv)->xhv_eiter) = HeNEXT(entry);
1648 hv_free_ent(hv, entry);
1653 I32 placeholders = HvPLACEHOLDERS_get(hv);
1654 HvTOTALKEYS(hv) -= (IV)placeholders;
1655 /* HvUSEDKEYS expanded */
1656 if ((HvTOTALKEYS(hv) - placeholders) == 0)
1657 HvHASKFLAGS_off(hv);
1658 HvPLACEHOLDERS_set(hv, 0);
1662 oentry = &HeNEXT(entry);
1666 /* You can't get here, hence assertion should always fail. */
1667 assert (items == 0);
1672 S_hfreeentries(pTHX_ HV *hv)
1675 XPVHV * const xhv = (XPVHV*)SvANY(hv);
1678 PERL_ARGS_ASSERT_HFREEENTRIES;
1680 while ((sv = Perl_hfree_next_entry(aTHX_ hv, &index))||xhv->xhv_keys) {
1686 /* hfree_next_entry()
1687 * For use only by S_hfreeentries() and sv_clear().
1688 * Delete the next available HE from hv and return the associated SV.
1689 * Returns null on empty hash. Nevertheless null is not a reliable
1690 * indicator that the hash is empty, as the deleted entry may have a
1692 * indexp is a pointer to the current index into HvARRAY. The index should
1693 * initially be set to 0. hfree_next_entry() may update it. */
1696 Perl_hfree_next_entry(pTHX_ HV *hv, STRLEN *indexp)
1698 struct xpvhv_aux *iter;
1702 STRLEN orig_index = *indexp;
1705 PERL_ARGS_ASSERT_HFREE_NEXT_ENTRY;
1707 if (SvOOK(hv) && ((iter = HvAUX(hv)))) {
1708 if ((entry = iter->xhv_eiter)) {
1709 /* the iterator may get resurrected after each
1710 * destructor call, so check each time */
1711 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1713 hv_free_ent(hv, entry);
1714 /* warning: at this point HvARRAY may have been
1715 * re-allocated, HvMAX changed etc */
1717 iter = HvAUX(hv); /* may have been realloced */
1718 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1719 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1720 #ifdef PERL_HASH_RANDOMIZE_KEYS
1721 iter->xhv_last_rand = iter->xhv_rand;
1724 /* Reset any cached HvFILL() to "unknown". It's unlikely that anyone
1725 will actually call HvFILL() on a hash under destruction, so it
1726 seems pointless attempting to track the number of keys remaining.
1727 But if they do, we want to reset it again. */
1728 if (iter->xhv_fill_lazy)
1729 iter->xhv_fill_lazy = 0;
1732 if (!((XPVHV*)SvANY(hv))->xhv_keys)
1735 array = HvARRAY(hv);
1737 while ( ! ((entry = array[*indexp])) ) {
1738 if ((*indexp)++ >= HvMAX(hv))
1740 assert(*indexp != orig_index);
1742 array[*indexp] = HeNEXT(entry);
1743 ((XPVHV*) SvANY(hv))->xhv_keys--;
1745 if ( PL_phase != PERL_PHASE_DESTRUCT && HvENAME(hv)
1746 && HeVAL(entry) && isGV(HeVAL(entry))
1747 && GvHV(HeVAL(entry)) && HvENAME(GvHV(HeVAL(entry)))
1750 const char * const key = HePV(entry,klen);
1751 if ((klen > 1 && key[klen-1]==':' && key[klen-2]==':')
1752 || (klen == 1 && key[0] == ':')) {
1754 NULL, GvHV(HeVAL(entry)),
1755 (GV *)HeVAL(entry), 0
1759 return hv_free_ent_ret(hv, entry);
1764 =for apidoc hv_undef
1766 Undefines the hash. The XS equivalent of C<undef(%hash)>.
1768 As well as freeing all the elements of the hash (like hv_clear()), this
1769 also frees any auxiliary data and storage associated with the hash.
1771 If any destructors are triggered as a result, the hv itself may
1774 See also L</hv_clear>.
1780 Perl_hv_undef_flags(pTHX_ HV *hv, U32 flags)
1788 save = !!SvREFCNT(hv);
1789 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1790 xhv = (XPVHV*)SvANY(hv);
1792 /* The name must be deleted before the call to hfreeeeentries so that
1793 CVs are anonymised properly. But the effective name must be pre-
1794 served until after that call (and only deleted afterwards if the
1795 call originated from sv_clear). For stashes with one name that is
1796 both the canonical name and the effective name, hv_name_set has to
1797 allocate an array for storing the effective name. We can skip that
1798 during global destruction, as it does not matter where the CVs point
1799 if they will be freed anyway. */
1800 /* note that the code following prior to hfreeentries is duplicated
1801 * in sv_clear(), and changes here should be done there too */
1802 if (PL_phase != PERL_PHASE_DESTRUCT && HvNAME(hv)) {
1803 if (PL_stashcache) {
1804 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for '%"
1805 HEKf"'\n", HvNAME_HEK(hv)));
1806 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1808 hv_name_set(hv, NULL, 0, 0);
1812 SAVEFREESV(SvREFCNT_inc_simple_NN(hv));
1816 struct mro_meta *meta;
1819 if (HvENAME_get(hv)) {
1820 if (PL_phase != PERL_PHASE_DESTRUCT)
1821 mro_isa_changed_in(hv);
1822 if (PL_stashcache) {
1823 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for effective name '%"
1824 HEKf"'\n", HvENAME_HEK(hv)));
1825 (void)hv_deletehek(PL_stashcache, HvENAME_HEK(hv), G_DISCARD);
1829 /* If this call originated from sv_clear, then we must check for
1830 * effective names that need freeing, as well as the usual name. */
1832 if (flags & HV_NAME_SETALL ? !!HvAUX(hv)->xhv_name_u.xhvnameu_name : !!name) {
1833 if (name && PL_stashcache) {
1834 DEBUG_o(Perl_deb(aTHX_ "hv_undef_flags clearing PL_stashcache for name '%"
1835 HEKf"'\n", HvNAME_HEK(hv)));
1836 (void)hv_deletehek(PL_stashcache, HvNAME_HEK(hv), G_DISCARD);
1838 hv_name_set(hv, NULL, 0, flags);
1840 if((meta = HvAUX(hv)->xhv_mro_meta)) {
1841 if (meta->mro_linear_all) {
1842 SvREFCNT_dec_NN(meta->mro_linear_all);
1843 /* mro_linear_current is just acting as a shortcut pointer,
1847 /* Only the current MRO is stored, so this owns the data.
1849 SvREFCNT_dec(meta->mro_linear_current);
1850 SvREFCNT_dec(meta->mro_nextmethod);
1851 SvREFCNT_dec(meta->isa);
1852 SvREFCNT_dec(meta->super);
1854 HvAUX(hv)->xhv_mro_meta = NULL;
1856 if (!HvAUX(hv)->xhv_name_u.xhvnameu_name && ! HvAUX(hv)->xhv_backreferences)
1857 SvFLAGS(hv) &= ~SVf_OOK;
1860 Safefree(HvARRAY(hv));
1861 xhv->xhv_max = PERL_HASH_DEFAULT_HvMAX; /* HvMAX(hv) = 7 (it's a normal hash) */
1864 /* if we're freeing the HV, the SvMAGIC field has been reused for
1865 * other purposes, and so there can't be any placeholder magic */
1867 HvPLACEHOLDERS_set(hv, 0);
1870 mg_clear(MUTABLE_SV(hv));
1877 Returns the number of hash buckets that
1878 happen to be in use. This function is
1879 wrapped by the macro C<HvFILL>.
1881 Previously this value was always stored in the HV structure, which created an
1882 overhead on every hash (and pretty much every object) for something that was
1883 rarely used. Now we calculate it on demand the first
1884 time that it is needed, and cache it if that calculation
1885 is going to be costly to repeat. The cached
1886 value is updated by insertions and deletions, but (currently) discarded if
1893 Perl_hv_fill(pTHX_ HV *const hv)
1896 HE **ents = HvARRAY(hv);
1897 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : NULL;
1899 PERL_ARGS_ASSERT_HV_FILL;
1901 /* No keys implies no buckets used.
1902 One key can only possibly mean one bucket used. */
1903 if (HvTOTALKEYS(hv) < 2)
1904 return HvTOTALKEYS(hv);
1907 if (aux && aux->xhv_fill_lazy)
1908 return aux->xhv_fill_lazy;
1912 HE *const *const last = ents + HvMAX(hv);
1913 count = last + 1 - ents;
1918 } while (++ents <= last);
1922 if (aux->xhv_fill_lazy)
1923 assert(aux->xhv_fill_lazy == count);
1925 aux->xhv_fill_lazy = count;
1926 } else if (HvMAX(hv) >= HV_FILL_THRESHOLD) {
1927 aux = hv_auxinit(hv);
1928 aux->xhv_fill_lazy = count;
1933 /* hash a pointer to a U32 - Used in the hash traversal randomization
1934 * and bucket order randomization code
1936 * this code was derived from Sereal, which was derived from autobox.
1939 PERL_STATIC_INLINE U32 S_ptr_hash(PTRV u) {
1942 * This is one of Thomas Wang's hash functions for 64-bit integers from:
1943 * http://www.concentric.net/~Ttwang/tech/inthash.htm
1945 u = (~u) + (u << 18);
1953 * This is one of Bob Jenkins' hash functions for 32-bit integers
1954 * from: http://burtleburtle.net/bob/hash/integer.html
1956 u = (u + 0x7ed55d16) + (u << 12);
1957 u = (u ^ 0xc761c23c) ^ (u >> 19);
1958 u = (u + 0x165667b1) + (u << 5);
1959 u = (u + 0xd3a2646c) ^ (u << 9);
1960 u = (u + 0xfd7046c5) + (u << 3);
1961 u = (u ^ 0xb55a4f09) ^ (u >> 16);
1966 static struct xpvhv_aux*
1967 S_hv_auxinit_internal(struct xpvhv_aux *iter) {
1968 PERL_ARGS_ASSERT_HV_AUXINIT_INTERNAL;
1969 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1970 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1971 #ifdef PERL_HASH_RANDOMIZE_KEYS
1972 iter->xhv_last_rand = iter->xhv_rand;
1974 iter->xhv_fill_lazy = 0;
1975 iter->xhv_name_u.xhvnameu_name = 0;
1976 iter->xhv_name_count = 0;
1977 iter->xhv_backreferences = 0;
1978 iter->xhv_mro_meta = NULL;
1979 iter->xhv_aux_flags = 0;
1984 static struct xpvhv_aux*
1985 S_hv_auxinit(pTHX_ HV *hv) {
1986 struct xpvhv_aux *iter;
1989 PERL_ARGS_ASSERT_HV_AUXINIT;
1993 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1994 + sizeof(struct xpvhv_aux), char);
1996 array = (char *) HvARRAY(hv);
1997 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1998 + sizeof(struct xpvhv_aux), char);
2000 HvARRAY(hv) = (HE**)array;
2003 #ifdef PERL_HASH_RANDOMIZE_KEYS
2004 if (PL_HASH_RAND_BITS_ENABLED) {
2005 /* mix in some new state to PL_hash_rand_bits to "randomize" the traversal order*/
2006 if (PL_HASH_RAND_BITS_ENABLED == 1)
2007 PL_hash_rand_bits += ptr_hash((PTRV)array);
2008 PL_hash_rand_bits = ROTL_UV(PL_hash_rand_bits,1);
2010 iter->xhv_rand = (U32)PL_hash_rand_bits;
2016 return hv_auxinit_internal(iter);
2020 =for apidoc hv_iterinit
2022 Prepares a starting point to traverse a hash table. Returns the number of
2023 keys in the hash (i.e. the same as C<HvUSEDKEYS(hv)>). The return value is
2024 currently only meaningful for hashes without tie magic.
2026 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
2027 hash buckets that happen to be in use. If you still need that esoteric
2028 value, you can get it through the macro C<HvFILL(hv)>.
2035 Perl_hv_iterinit(pTHX_ HV *hv)
2037 PERL_ARGS_ASSERT_HV_ITERINIT;
2039 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
2042 Perl_croak(aTHX_ "Bad hash");
2045 struct xpvhv_aux * iter = HvAUX(hv);
2046 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
2047 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2049 hv_free_ent(hv, entry);
2051 iter = HvAUX(hv); /* may have been reallocated */
2052 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2053 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2054 #ifdef PERL_HASH_RANDOMIZE_KEYS
2055 iter->xhv_last_rand = iter->xhv_rand;
2061 /* used to be xhv->xhv_fill before 5.004_65 */
2062 return HvTOTALKEYS(hv);
2066 Perl_hv_riter_p(pTHX_ HV *hv) {
2067 struct xpvhv_aux *iter;
2069 PERL_ARGS_ASSERT_HV_RITER_P;
2072 Perl_croak(aTHX_ "Bad hash");
2074 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2075 return &(iter->xhv_riter);
2079 Perl_hv_eiter_p(pTHX_ HV *hv) {
2080 struct xpvhv_aux *iter;
2082 PERL_ARGS_ASSERT_HV_EITER_P;
2085 Perl_croak(aTHX_ "Bad hash");
2087 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2088 return &(iter->xhv_eiter);
2092 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
2093 struct xpvhv_aux *iter;
2095 PERL_ARGS_ASSERT_HV_RITER_SET;
2098 Perl_croak(aTHX_ "Bad hash");
2106 iter = hv_auxinit(hv);
2108 iter->xhv_riter = riter;
2112 Perl_hv_rand_set(pTHX_ HV *hv, U32 new_xhv_rand) {
2113 struct xpvhv_aux *iter;
2115 PERL_ARGS_ASSERT_HV_RAND_SET;
2117 #ifdef PERL_HASH_RANDOMIZE_KEYS
2119 Perl_croak(aTHX_ "Bad hash");
2124 iter = hv_auxinit(hv);
2126 iter->xhv_rand = new_xhv_rand;
2128 Perl_croak(aTHX_ "This Perl has not been built with support for randomized hash key traversal but something called Perl_hv_rand_set().");
2133 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2134 struct xpvhv_aux *iter;
2136 PERL_ARGS_ASSERT_HV_EITER_SET;
2139 Perl_croak(aTHX_ "Bad hash");
2144 /* 0 is the default so don't go malloc()ing a new structure just to
2149 iter = hv_auxinit(hv);
2151 iter->xhv_eiter = eiter;
2155 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2158 struct xpvhv_aux *iter;
2162 PERL_ARGS_ASSERT_HV_NAME_SET;
2165 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2169 if (iter->xhv_name_u.xhvnameu_name) {
2170 if(iter->xhv_name_count) {
2171 if(flags & HV_NAME_SETALL) {
2172 HEK ** const name = HvAUX(hv)->xhv_name_u.xhvnameu_names;
2173 HEK **hekp = name + (
2174 iter->xhv_name_count < 0
2175 ? -iter->xhv_name_count
2176 : iter->xhv_name_count
2178 while(hekp-- > name+1)
2179 unshare_hek_or_pvn(*hekp, 0, 0, 0);
2180 /* The first elem may be null. */
2181 if(*name) unshare_hek_or_pvn(*name, 0, 0, 0);
2183 iter = HvAUX(hv); /* may been realloced */
2184 spot = &iter->xhv_name_u.xhvnameu_name;
2185 iter->xhv_name_count = 0;
2188 if(iter->xhv_name_count > 0) {
2189 /* shift some things over */
2191 iter->xhv_name_u.xhvnameu_names, iter->xhv_name_count + 1, HEK *
2193 spot = iter->xhv_name_u.xhvnameu_names;
2194 spot[iter->xhv_name_count] = spot[1];
2196 iter->xhv_name_count = -(iter->xhv_name_count + 1);
2198 else if(*(spot = iter->xhv_name_u.xhvnameu_names)) {
2199 unshare_hek_or_pvn(*spot, 0, 0, 0);
2203 else if (flags & HV_NAME_SETALL) {
2204 unshare_hek_or_pvn(iter->xhv_name_u.xhvnameu_name, 0, 0, 0);
2205 iter = HvAUX(hv); /* may been realloced */
2206 spot = &iter->xhv_name_u.xhvnameu_name;
2209 HEK * const existing_name = iter->xhv_name_u.xhvnameu_name;
2210 Newx(iter->xhv_name_u.xhvnameu_names, 2, HEK *);
2211 iter->xhv_name_count = -2;
2212 spot = iter->xhv_name_u.xhvnameu_names;
2213 spot[1] = existing_name;
2216 else { spot = &iter->xhv_name_u.xhvnameu_name; iter->xhv_name_count = 0; }
2221 iter = hv_auxinit(hv);
2222 spot = &iter->xhv_name_u.xhvnameu_name;
2224 PERL_HASH(hash, name, len);
2225 *spot = name ? share_hek(name, flags & SVf_UTF8 ? -(I32)len : (I32)len, hash) : NULL;
2229 This is basically sv_eq_flags() in sv.c, but we avoid the magic
2234 hek_eq_pvn_flags(pTHX_ const HEK *hek, const char* pv, const I32 pvlen, const U32 flags) {
2235 if ( (HEK_UTF8(hek) ? 1 : 0) != (flags & SVf_UTF8 ? 1 : 0) ) {
2236 if (flags & SVf_UTF8)
2237 return (bytes_cmp_utf8(
2238 (const U8*)HEK_KEY(hek), HEK_LEN(hek),
2239 (const U8*)pv, pvlen) == 0);
2241 return (bytes_cmp_utf8(
2242 (const U8*)pv, pvlen,
2243 (const U8*)HEK_KEY(hek), HEK_LEN(hek)) == 0);
2246 return HEK_LEN(hek) == pvlen && ((HEK_KEY(hek) == pv)
2247 || memEQ(HEK_KEY(hek), pv, pvlen));
2251 =for apidoc hv_ename_add
2253 Adds a name to a stash's internal list of effective names. See
2256 This is called when a stash is assigned to a new location in the symbol
2263 Perl_hv_ename_add(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2266 struct xpvhv_aux *aux = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2269 PERL_ARGS_ASSERT_HV_ENAME_ADD;
2272 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2274 PERL_HASH(hash, name, len);
2276 if (aux->xhv_name_count) {
2277 HEK ** const xhv_name = aux->xhv_name_u.xhvnameu_names;
2278 I32 count = aux->xhv_name_count;
2279 HEK **hekp = xhv_name + (count < 0 ? -count : count);
2280 while (hekp-- > xhv_name)
2282 (HEK_UTF8(*hekp) || (flags & SVf_UTF8))
2283 ? hek_eq_pvn_flags(aTHX_ *hekp, name, (I32)len, flags)
2284 : (HEK_LEN(*hekp) == (I32)len && memEQ(HEK_KEY(*hekp), name, len))
2286 if (hekp == xhv_name && count < 0)
2287 aux->xhv_name_count = -count;
2290 if (count < 0) aux->xhv_name_count--, count = -count;
2291 else aux->xhv_name_count++;
2292 Renew(aux->xhv_name_u.xhvnameu_names, count + 1, HEK *);
2293 (aux->xhv_name_u.xhvnameu_names)[count] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2296 HEK *existing_name = aux->xhv_name_u.xhvnameu_name;
2299 (HEK_UTF8(existing_name) || (flags & SVf_UTF8))
2300 ? hek_eq_pvn_flags(aTHX_ existing_name, name, (I32)len, flags)
2301 : (HEK_LEN(existing_name) == (I32)len && memEQ(HEK_KEY(existing_name), name, len))
2304 Newx(aux->xhv_name_u.xhvnameu_names, 2, HEK *);
2305 aux->xhv_name_count = existing_name ? 2 : -2;
2306 *aux->xhv_name_u.xhvnameu_names = existing_name;
2307 (aux->xhv_name_u.xhvnameu_names)[1] = share_hek(name, (flags & SVf_UTF8 ? -(I32)len : (I32)len), hash);
2312 =for apidoc hv_ename_delete
2314 Removes a name from a stash's internal list of effective names. If this is
2315 the name returned by C<HvENAME>, then another name in the list will take
2316 its place (C<HvENAME> will use it).
2318 This is called when a stash is deleted from the symbol table.
2324 Perl_hv_ename_delete(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2327 struct xpvhv_aux *aux;
2329 PERL_ARGS_ASSERT_HV_ENAME_DELETE;
2332 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2334 if (!SvOOK(hv)) return;
2337 if (!aux->xhv_name_u.xhvnameu_name) return;
2339 if (aux->xhv_name_count) {
2340 HEK ** const namep = aux->xhv_name_u.xhvnameu_names;
2341 I32 const count = aux->xhv_name_count;
2342 HEK **victim = namep + (count < 0 ? -count : count);
2343 while (victim-- > namep + 1)
2345 (HEK_UTF8(*victim) || (flags & SVf_UTF8))
2346 ? hek_eq_pvn_flags(aTHX_ *victim, name, (I32)len, flags)
2347 : (HEK_LEN(*victim) == (I32)len && memEQ(HEK_KEY(*victim), name, len))
2349 unshare_hek_or_pvn(*victim, 0, 0, 0);
2350 aux = HvAUX(hv); /* may been realloced */
2351 if (count < 0) ++aux->xhv_name_count;
2352 else --aux->xhv_name_count;
2354 (aux->xhv_name_count == 1 || aux->xhv_name_count == -1)
2356 ) { /* if there are none left */
2358 aux->xhv_name_u.xhvnameu_names = NULL;
2359 aux->xhv_name_count = 0;
2362 /* Move the last one back to fill the empty slot. It
2363 does not matter what order they are in. */
2364 *victim = *(namep + (count < 0 ? -count : count) - 1);
2369 count > 0 && (HEK_UTF8(*namep) || (flags & SVf_UTF8))
2370 ? hek_eq_pvn_flags(aTHX_ *namep, name, (I32)len, flags)
2371 : (HEK_LEN(*namep) == (I32)len && memEQ(HEK_KEY(*namep), name, len))
2373 aux->xhv_name_count = -count;
2377 (HEK_UTF8(aux->xhv_name_u.xhvnameu_name) || (flags & SVf_UTF8))
2378 ? hek_eq_pvn_flags(aTHX_ aux->xhv_name_u.xhvnameu_name, name, (I32)len, flags)
2379 : (HEK_LEN(aux->xhv_name_u.xhvnameu_name) == (I32)len &&
2380 memEQ(HEK_KEY(aux->xhv_name_u.xhvnameu_name), name, len))
2382 HEK * const namehek = aux->xhv_name_u.xhvnameu_name;
2383 Newx(aux->xhv_name_u.xhvnameu_names, 1, HEK *);
2384 *aux->xhv_name_u.xhvnameu_names = namehek;
2385 aux->xhv_name_count = -1;
2390 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2391 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2393 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2394 PERL_UNUSED_CONTEXT;
2396 return &(iter->xhv_backreferences);
2400 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2403 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2408 av = HvAUX(hv)->xhv_backreferences;
2411 HvAUX(hv)->xhv_backreferences = 0;
2412 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2413 if (SvTYPE(av) == SVt_PVAV)
2414 SvREFCNT_dec_NN(av);
2419 hv_iternext is implemented as a macro in hv.h
2421 =for apidoc hv_iternext
2423 Returns entries from a hash iterator. See C<hv_iterinit>.
2425 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2426 iterator currently points to, without losing your place or invalidating your
2427 iterator. Note that in this case the current entry is deleted from the hash
2428 with your iterator holding the last reference to it. Your iterator is flagged
2429 to free the entry on the next call to C<hv_iternext>, so you must not discard
2430 your iterator immediately else the entry will leak - call C<hv_iternext> to
2431 trigger the resource deallocation.
2433 =for apidoc hv_iternext_flags
2435 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2436 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2437 set the placeholders keys (for restricted hashes) will be returned in addition
2438 to normal keys. By default placeholders are automatically skipped over.
2439 Currently a placeholder is implemented with a value that is
2440 C<&PL_sv_placeholder>. Note that the implementation of placeholders and
2441 restricted hashes may change, and the implementation currently is
2442 insufficiently abstracted for any change to be tidy.
2448 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2455 struct xpvhv_aux *iter;
2457 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2460 Perl_croak(aTHX_ "Bad hash");
2462 xhv = (XPVHV*)SvANY(hv);
2465 /* Too many things (well, pp_each at least) merrily assume that you can
2466 call hv_iternext without calling hv_iterinit, so we'll have to deal
2472 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2473 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2474 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2475 SV * const key = sv_newmortal();
2477 sv_setsv(key, HeSVKEY_force(entry));
2478 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2479 HeSVKEY_set(entry, NULL);
2485 /* one HE per MAGICAL hash */
2486 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2487 HvLAZYDEL_on(hv); /* make sure entry gets freed */
2489 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2491 HeKEY_hek(entry) = hek;
2492 HeKLEN(entry) = HEf_SVKEY;
2494 magic_nextpack(MUTABLE_SV(hv),mg,key);
2496 /* force key to stay around until next time */
2497 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2498 return entry; /* beware, hent_val is not set */
2500 SvREFCNT_dec(HeVAL(entry));
2501 Safefree(HeKEY_hek(entry));
2503 iter = HvAUX(hv); /* may been realloced */
2504 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2509 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2510 if (!entry && SvRMAGICAL((const SV *)hv)
2511 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2514 /* The prime_env_iter() on VMS just loaded up new hash values
2515 * so the iteration count needs to be reset back to the beginning
2519 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2524 /* hv_iterinit now ensures this. */
2525 assert (HvARRAY(hv));
2527 /* At start of hash, entry is NULL. */
2530 entry = HeNEXT(entry);
2531 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2533 * Skip past any placeholders -- don't want to include them in
2536 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2537 entry = HeNEXT(entry);
2542 #ifdef PERL_HASH_RANDOMIZE_KEYS
2543 if (iter->xhv_last_rand != iter->xhv_rand) {
2544 if (iter->xhv_riter != -1) {
2545 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2546 "Use of each() on hash after insertion without resetting hash iterator results in undefined behavior"
2550 iter = HvAUX(hv); /* may been realloced */
2551 iter->xhv_last_rand = iter->xhv_rand;
2555 /* Skip the entire loop if the hash is empty. */
2556 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2557 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2559 /* OK. Come to the end of the current list. Grab the next one. */
2561 iter->xhv_riter++; /* HvRITER(hv)++ */
2562 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2563 /* There is no next one. End of the hash. */
2564 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2565 #ifdef PERL_HASH_RANDOMIZE_KEYS
2566 iter->xhv_last_rand = iter->xhv_rand; /* reset xhv_last_rand so we can detect inserts during traversal */
2570 entry = (HvARRAY(hv))[ PERL_HASH_ITER_BUCKET(iter) & xhv->xhv_max ];
2572 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2573 /* If we have an entry, but it's a placeholder, don't count it.
2575 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2576 entry = HeNEXT(entry);
2578 /* Will loop again if this linked list starts NULL
2579 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2580 or if we run through it and find only placeholders. */
2584 iter->xhv_riter = -1;
2585 #ifdef PERL_HASH_RANDOMIZE_KEYS
2586 iter->xhv_last_rand = iter->xhv_rand;
2590 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2592 hv_free_ent(hv, oldentry);
2595 iter = HvAUX(hv); /* may been realloced */
2596 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2601 =for apidoc hv_iterkey
2603 Returns the key from the current position of the hash iterator. See
2610 Perl_hv_iterkey(pTHX_ HE *entry, I32 *retlen)
2612 PERL_ARGS_ASSERT_HV_ITERKEY;
2614 if (HeKLEN(entry) == HEf_SVKEY) {
2616 char * const p = SvPV(HeKEY_sv(entry), len);
2621 *retlen = HeKLEN(entry);
2622 return HeKEY(entry);
2626 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2628 =for apidoc hv_iterkeysv
2630 Returns the key as an C<SV*> from the current position of the hash
2631 iterator. The return value will always be a mortal copy of the key. Also
2638 Perl_hv_iterkeysv(pTHX_ HE *entry)
2640 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2642 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2646 =for apidoc hv_iterval
2648 Returns the value from the current position of the hash iterator. See
2655 Perl_hv_iterval(pTHX_ HV *hv, HE *entry)
2657 PERL_ARGS_ASSERT_HV_ITERVAL;
2659 if (SvRMAGICAL(hv)) {
2660 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2661 SV* const sv = sv_newmortal();
2662 if (HeKLEN(entry) == HEf_SVKEY)
2663 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2665 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2669 return HeVAL(entry);
2673 =for apidoc hv_iternextsv
2675 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2682 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2684 HE * const he = hv_iternext_flags(hv, 0);
2686 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2690 *key = hv_iterkey(he, retlen);
2691 return hv_iterval(hv, he);
2698 =for apidoc hv_magic
2700 Adds magic to a hash. See C<sv_magic>.
2705 /* possibly free a shared string if no one has access to it
2706 * len and hash must both be valid for str.
2709 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2711 unshare_hek_or_pvn (NULL, str, len, hash);
2716 Perl_unshare_hek(pTHX_ HEK *hek)
2719 unshare_hek_or_pvn(hek, NULL, 0, 0);
2722 /* possibly free a shared string if no one has access to it
2723 hek if non-NULL takes priority over the other 3, else str, len and hash
2724 are used. If so, len and hash must both be valid for str.
2727 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2733 bool is_utf8 = FALSE;
2735 const char * const save = str;
2736 struct shared_he *he = NULL;
2739 /* Find the shared he which is just before us in memory. */
2740 he = (struct shared_he *)(((char *)hek)
2741 - STRUCT_OFFSET(struct shared_he,
2744 /* Assert that the caller passed us a genuine (or at least consistent)
2746 assert (he->shared_he_he.hent_hek == hek);
2748 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2749 --he->shared_he_he.he_valu.hent_refcount;
2753 hash = HEK_HASH(hek);
2754 } else if (len < 0) {
2755 STRLEN tmplen = -len;
2757 /* See the note in hv_fetch(). --jhi */
2758 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2761 k_flags = HVhek_UTF8;
2763 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2766 /* what follows was the moral equivalent of:
2767 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2769 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2771 xhv = (XPVHV*)SvANY(PL_strtab);
2772 /* assert(xhv_array != 0) */
2773 oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2775 const HE *const he_he = &(he->shared_he_he);
2776 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2781 const int flags_masked = k_flags & HVhek_MASK;
2782 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2783 if (HeHASH(entry) != hash) /* strings can't be equal */
2785 if (HeKLEN(entry) != len)
2787 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2789 if (HeKFLAGS(entry) != flags_masked)
2796 if (--entry->he_valu.hent_refcount == 0) {
2797 *oentry = HeNEXT(entry);
2799 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2804 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2805 "Attempt to free nonexistent shared string '%s'%s"
2807 hek ? HEK_KEY(hek) : str,
2808 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2809 if (k_flags & HVhek_FREEKEY)
2813 /* get a (constant) string ptr from the global string table
2814 * string will get added if it is not already there.
2815 * len and hash must both be valid for str.
2818 Perl_share_hek(pTHX_ const char *str, I32 len, U32 hash)
2820 bool is_utf8 = FALSE;
2822 const char * const save = str;
2824 PERL_ARGS_ASSERT_SHARE_HEK;
2827 STRLEN tmplen = -len;
2829 /* See the note in hv_fetch(). --jhi */
2830 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2832 /* If we were able to downgrade here, then than means that we were passed
2833 in a key which only had chars 0-255, but was utf8 encoded. */
2836 /* If we found we were able to downgrade the string to bytes, then
2837 we should flag that it needs upgrading on keys or each. Also flag
2838 that we need share_hek_flags to free the string. */
2841 PERL_HASH(hash, str, len);
2842 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2846 return share_hek_flags (str, len, hash, flags);
2850 S_share_hek_flags(pTHX_ const char *str, I32 len, U32 hash, int flags)
2854 const int flags_masked = flags & HVhek_MASK;
2855 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2856 XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2858 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2860 /* what follows is the moral equivalent of:
2862 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2863 hv_store(PL_strtab, str, len, NULL, hash);
2865 Can't rehash the shared string table, so not sure if it's worth
2866 counting the number of entries in the linked list
2869 /* assert(xhv_array != 0) */
2870 entry = (HvARRAY(PL_strtab))[hindex];
2871 for (;entry; entry = HeNEXT(entry)) {
2872 if (HeHASH(entry) != hash) /* strings can't be equal */
2874 if (HeKLEN(entry) != len)
2876 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2878 if (HeKFLAGS(entry) != flags_masked)
2884 /* What used to be head of the list.
2885 If this is NULL, then we're the first entry for this slot, which
2886 means we need to increate fill. */
2887 struct shared_he *new_entry;
2890 HE **const head = &HvARRAY(PL_strtab)[hindex];
2891 HE *const next = *head;
2893 /* We don't actually store a HE from the arena and a regular HEK.
2894 Instead we allocate one chunk of memory big enough for both,
2895 and put the HEK straight after the HE. This way we can find the
2896 HE directly from the HEK.
2899 Newx(k, STRUCT_OFFSET(struct shared_he,
2900 shared_he_hek.hek_key[0]) + len + 2, char);
2901 new_entry = (struct shared_he *)k;
2902 entry = &(new_entry->shared_he_he);
2903 hek = &(new_entry->shared_he_hek);
2905 Copy(str, HEK_KEY(hek), len, char);
2906 HEK_KEY(hek)[len] = 0;
2908 HEK_HASH(hek) = hash;
2909 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2911 /* Still "point" to the HEK, so that other code need not know what
2913 HeKEY_hek(entry) = hek;
2914 entry->he_valu.hent_refcount = 0;
2915 HeNEXT(entry) = next;
2918 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2919 if (!next) { /* initial entry? */
2920 } else if ( DO_HSPLIT(xhv) ) {
2921 const STRLEN oldsize = xhv->xhv_max + 1;
2922 hsplit(PL_strtab, oldsize, oldsize * 2);
2926 ++entry->he_valu.hent_refcount;
2928 if (flags & HVhek_FREEKEY)
2931 return HeKEY_hek(entry);
2935 Perl_hv_placeholders_p(pTHX_ HV *hv)
2938 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2940 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2943 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2946 Perl_die(aTHX_ "panic: hv_placeholders_p");
2949 return &(mg->mg_len);
2954 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2957 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2959 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2961 return mg ? mg->mg_len : 0;
2965 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2968 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2970 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2975 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2976 Perl_die(aTHX_ "panic: hv_placeholders_set");
2978 /* else we don't need to add magic to record 0 placeholders. */
2982 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2987 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2989 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2994 value = &PL_sv_placeholder;
2997 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
3000 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
3003 case HVrhek_PV_UTF8:
3004 /* Create a string SV that directly points to the bytes in our
3006 value = newSV_type(SVt_PV);
3007 SvPV_set(value, (char *) he->refcounted_he_data + 1);
3008 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
3009 /* This stops anything trying to free it */
3010 SvLEN_set(value, 0);
3012 SvREADONLY_on(value);
3013 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
3017 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %"UVxf,
3018 (UV)he->refcounted_he_data[0]);
3024 =for apidoc m|HV *|refcounted_he_chain_2hv|const struct refcounted_he *c|U32 flags
3026 Generates and returns a C<HV *> representing the content of a
3027 C<refcounted_he> chain.
3028 I<flags> is currently unused and must be zero.
3033 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain, U32 flags)
3037 U32 placeholders, max;
3040 Perl_croak(aTHX_ "panic: refcounted_he_chain_2hv bad flags %"UVxf,
3043 /* We could chase the chain once to get an idea of the number of keys,
3044 and call ksplit. But for now we'll make a potentially inefficient
3045 hash with only 8 entries in its array. */
3050 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
3051 HvARRAY(hv) = (HE**)array;
3057 U32 hash = chain->refcounted_he_hash;
3059 U32 hash = HEK_HASH(chain->refcounted_he_hek);
3061 HE **oentry = &((HvARRAY(hv))[hash & max]);
3062 HE *entry = *oentry;
3065 for (; entry; entry = HeNEXT(entry)) {
3066 if (HeHASH(entry) == hash) {
3067 /* We might have a duplicate key here. If so, entry is older
3068 than the key we've already put in the hash, so if they are
3069 the same, skip adding entry. */
3071 const STRLEN klen = HeKLEN(entry);
3072 const char *const key = HeKEY(entry);
3073 if (klen == chain->refcounted_he_keylen
3074 && (!!HeKUTF8(entry)
3075 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
3076 && memEQ(key, REF_HE_KEY(chain), klen))
3079 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
3081 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
3082 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
3083 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
3094 = share_hek_flags(REF_HE_KEY(chain),
3095 chain->refcounted_he_keylen,
3096 chain->refcounted_he_hash,
3097 (chain->refcounted_he_data[0]
3098 & (HVhek_UTF8|HVhek_WASUTF8)));
3100 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
3102 value = refcounted_he_value(chain);
3103 if (value == &PL_sv_placeholder)
3105 HeVAL(entry) = value;
3107 /* Link it into the chain. */
3108 HeNEXT(entry) = *oentry;
3114 chain = chain->refcounted_he_next;
3118 clear_placeholders(hv, placeholders);
3119 HvTOTALKEYS(hv) -= placeholders;
3122 /* We could check in the loop to see if we encounter any keys with key
3123 flags, but it's probably not worth it, as this per-hash flag is only
3124 really meant as an optimisation for things like Storable. */
3126 DEBUG_A(Perl_hv_assert(aTHX_ hv));
3132 =for apidoc m|SV *|refcounted_he_fetch_pvn|const struct refcounted_he *chain|const char *keypv|STRLEN keylen|U32 hash|U32 flags
3134 Search along a C<refcounted_he> chain for an entry with the key specified
3135 by I<keypv> and I<keylen>. If I<flags> has the C<REFCOUNTED_HE_KEY_UTF8>
3136 bit set, the key octets are interpreted as UTF-8, otherwise they
3137 are interpreted as Latin-1. I<hash> is a precomputed hash of the key
3138 string, or zero if it has not been precomputed. Returns a mortal scalar
3139 representing the value associated with the key, or C<&PL_sv_placeholder>
3140 if there is no value associated with the key.
3146 Perl_refcounted_he_fetch_pvn(pTHX_ const struct refcounted_he *chain,
3147 const char *keypv, STRLEN keylen, U32 hash, U32 flags)
3151 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PVN;
3153 if (flags & ~(REFCOUNTED_HE_KEY_UTF8|REFCOUNTED_HE_EXISTS))
3154 Perl_croak(aTHX_ "panic: refcounted_he_fetch_pvn bad flags %"UVxf,
3157 return &PL_sv_placeholder;
3158 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3159 /* For searching purposes, canonicalise to Latin-1 where possible. */
3160 const char *keyend = keypv + keylen, *p;
3161 STRLEN nonascii_count = 0;
3162 for (p = keypv; p != keyend; p++) {
3163 if (! UTF8_IS_INVARIANT(*p)) {
3164 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3165 goto canonicalised_key;
3171 if (nonascii_count) {
3173 const char *p = keypv, *keyend = keypv + keylen;
3174 keylen -= nonascii_count;
3175 Newx(q, keylen, char);
3178 for (; p != keyend; p++, q++) {
3180 if (UTF8_IS_INVARIANT(c)) {
3185 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3189 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3190 canonicalised_key: ;
3192 utf8_flag = (flags & REFCOUNTED_HE_KEY_UTF8) ? HVhek_UTF8 : 0;
3194 PERL_HASH(hash, keypv, keylen);
3196 for (; chain; chain = chain->refcounted_he_next) {
3199 hash == chain->refcounted_he_hash &&
3200 keylen == chain->refcounted_he_keylen &&
3201 memEQ(REF_HE_KEY(chain), keypv, keylen) &&
3202 utf8_flag == (chain->refcounted_he_data[0] & HVhek_UTF8)
3204 hash == HEK_HASH(chain->refcounted_he_hek) &&
3205 keylen == (STRLEN)HEK_LEN(chain->refcounted_he_hek) &&
3206 memEQ(HEK_KEY(chain->refcounted_he_hek), keypv, keylen) &&
3207 utf8_flag == (HEK_FLAGS(chain->refcounted_he_hek) & HVhek_UTF8)
3210 if (flags & REFCOUNTED_HE_EXISTS)
3211 return (chain->refcounted_he_data[0] & HVrhek_typemask)
3213 ? NULL : &PL_sv_yes;
3214 return sv_2mortal(refcounted_he_value(chain));
3217 return flags & REFCOUNTED_HE_EXISTS ? NULL : &PL_sv_placeholder;
3221 =for apidoc m|SV *|refcounted_he_fetch_pv|const struct refcounted_he *chain|const char *key|U32 hash|U32 flags
3223 Like L</refcounted_he_fetch_pvn>, but takes a nul-terminated string
3224 instead of a string/length pair.
3230 Perl_refcounted_he_fetch_pv(pTHX_ const struct refcounted_he *chain,
3231 const char *key, U32 hash, U32 flags)
3233 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_PV;
3234 return refcounted_he_fetch_pvn(chain, key, strlen(key), hash, flags);
3238 =for apidoc m|SV *|refcounted_he_fetch_sv|const struct refcounted_he *chain|SV *key|U32 hash|U32 flags
3240 Like L</refcounted_he_fetch_pvn>, but takes a Perl scalar instead of a
3247 Perl_refcounted_he_fetch_sv(pTHX_ const struct refcounted_he *chain,
3248 SV *key, U32 hash, U32 flags)
3252 PERL_ARGS_ASSERT_REFCOUNTED_HE_FETCH_SV;
3253 if (flags & REFCOUNTED_HE_KEY_UTF8)
3254 Perl_croak(aTHX_ "panic: refcounted_he_fetch_sv bad flags %"UVxf,
3256 keypv = SvPV_const(key, keylen);
3258 flags |= REFCOUNTED_HE_KEY_UTF8;
3259 if (!hash && SvIsCOW_shared_hash(key))
3260 hash = SvSHARED_HASH(key);
3261 return refcounted_he_fetch_pvn(chain, keypv, keylen, hash, flags);
3265 =for apidoc m|struct refcounted_he *|refcounted_he_new_pvn|struct refcounted_he *parent|const char *keypv|STRLEN keylen|U32 hash|SV *value|U32 flags
3267 Creates a new C<refcounted_he>. This consists of a single key/value
3268 pair and a reference to an existing C<refcounted_he> chain (which may
3269 be empty), and thus forms a longer chain. When using the longer chain,
3270 the new key/value pair takes precedence over any entry for the same key
3271 further along the chain.
3273 The new key is specified by I<keypv> and I<keylen>. If I<flags> has
3274 the C<REFCOUNTED_HE_KEY_UTF8> bit set, the key octets are interpreted
3275 as UTF-8, otherwise they are interpreted as Latin-1. I<hash> is
3276 a precomputed hash of the key string, or zero if it has not been
3279 I<value> is the scalar value to store for this key. I<value> is copied
3280 by this function, which thus does not take ownership of any reference
3281 to it, and later changes to the scalar will not be reflected in the
3282 value visible in the C<refcounted_he>. Complex types of scalar will not
3283 be stored with referential integrity, but will be coerced to strings.
3284 I<value> may be either null or C<&PL_sv_placeholder> to indicate that no
3285 value is to be associated with the key; this, as with any non-null value,
3286 takes precedence over the existence of a value for the key further along
3289 I<parent> points to the rest of the C<refcounted_he> chain to be
3290 attached to the new C<refcounted_he>. This function takes ownership
3291 of one reference to I<parent>, and returns one reference to the new
3297 struct refcounted_he *
3298 Perl_refcounted_he_new_pvn(pTHX_ struct refcounted_he *parent,
3299 const char *keypv, STRLEN keylen, U32 hash, SV *value, U32 flags)
3302 STRLEN value_len = 0;
3303 const char *value_p = NULL;
3307 STRLEN key_offset = 1;
3308 struct refcounted_he *he;
3309 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PVN;
3311 if (!value || value == &PL_sv_placeholder) {
3312 value_type = HVrhek_delete;
3313 } else if (SvPOK(value)) {
3314 value_type = HVrhek_PV;
3315 } else if (SvIOK(value)) {
3316 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
3317 } else if (!SvOK(value)) {
3318 value_type = HVrhek_undef;
3320 value_type = HVrhek_PV;
3322 is_pv = value_type == HVrhek_PV;
3324 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
3325 the value is overloaded, and doesn't yet have the UTF-8flag set. */
3326 value_p = SvPV_const(value, value_len);
3328 value_type = HVrhek_PV_UTF8;
3329 key_offset = value_len + 2;
3331 hekflags = value_type;
3333 if (flags & REFCOUNTED_HE_KEY_UTF8) {
3334 /* Canonicalise to Latin-1 where possible. */
3335 const char *keyend = keypv + keylen, *p;
3336 STRLEN nonascii_count = 0;
3337 for (p = keypv; p != keyend; p++) {
3338 if (! UTF8_IS_INVARIANT(*p)) {
3339 if (! UTF8_IS_NEXT_CHAR_DOWNGRADEABLE(p, keyend)) {
3340 goto canonicalised_key;
3346 if (nonascii_count) {
3348 const char *p = keypv, *keyend = keypv + keylen;
3349 keylen -= nonascii_count;
3350 Newx(q, keylen, char);
3353 for (; p != keyend; p++, q++) {
3355 if (UTF8_IS_INVARIANT(c)) {
3360 *q = (char) TWO_BYTE_UTF8_TO_NATIVE(c, *p);
3364 flags &= ~REFCOUNTED_HE_KEY_UTF8;
3365 canonicalised_key: ;
3367 if (flags & REFCOUNTED_HE_KEY_UTF8)
3368 hekflags |= HVhek_UTF8;
3370 PERL_HASH(hash, keypv, keylen);
3373 he = (struct refcounted_he*)
3374 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3378 he = (struct refcounted_he*)
3379 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
3383 he->refcounted_he_next = parent;
3386 Copy(value_p, he->refcounted_he_data + 1, value_len + 1, char);
3387 he->refcounted_he_val.refcounted_he_u_len = value_len;
3388 } else if (value_type == HVrhek_IV) {
3389 he->refcounted_he_val.refcounted_he_u_iv = SvIVX(value);
3390 } else if (value_type == HVrhek_UV) {
3391 he->refcounted_he_val.refcounted_he_u_uv = SvUVX(value);
3395 he->refcounted_he_hash = hash;
3396 he->refcounted_he_keylen = keylen;
3397 Copy(keypv, he->refcounted_he_data + key_offset, keylen, char);
3399 he->refcounted_he_hek = share_hek_flags(keypv, keylen, hash, hekflags);
3402 he->refcounted_he_data[0] = hekflags;
3403 he->refcounted_he_refcnt = 1;
3409 =for apidoc m|struct refcounted_he *|refcounted_he_new_pv|struct refcounted_he *parent|const char *key|U32 hash|SV *value|U32 flags
3411 Like L</refcounted_he_new_pvn>, but takes a nul-terminated string instead
3412 of a string/length pair.
3417 struct refcounted_he *
3418 Perl_refcounted_he_new_pv(pTHX_ struct refcounted_he *parent,
3419 const char *key, U32 hash, SV *value, U32 flags)
3421 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_PV;
3422 return refcounted_he_new_pvn(parent, key, strlen(key), hash, value, flags);
3426 =for apidoc m|struct refcounted_he *|refcounted_he_new_sv|struct refcounted_he *parent|SV *key|U32 hash|SV *value|U32 flags
3428 Like L</refcounted_he_new_pvn>, but takes a Perl scalar instead of a
3434 struct refcounted_he *
3435 Perl_refcounted_he_new_sv(pTHX_ struct refcounted_he *parent,
3436 SV *key, U32 hash, SV *value, U32 flags)
3440 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_SV;
3441 if (flags & REFCOUNTED_HE_KEY_UTF8)
3442 Perl_croak(aTHX_ "panic: refcounted_he_new_sv bad flags %"UVxf,
3444 keypv = SvPV_const(key, keylen);
3446 flags |= REFCOUNTED_HE_KEY_UTF8;
3447 if (!hash && SvIsCOW_shared_hash(key))
3448 hash = SvSHARED_HASH(key);
3449 return refcounted_he_new_pvn(parent, keypv, keylen, hash, value, flags);
3453 =for apidoc m|void|refcounted_he_free|struct refcounted_he *he
3455 Decrements the reference count of a C<refcounted_he> by one. If the
3456 reference count reaches zero the structure's memory is freed, which
3457 (recursively) causes a reduction of its parent C<refcounted_he>'s
3458 reference count. It is safe to pass a null pointer to this function:
3459 no action occurs in this case.
3465 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
3467 PERL_UNUSED_CONTEXT;
3470 struct refcounted_he *copy;
3474 new_count = --he->refcounted_he_refcnt;
3475 HINTS_REFCNT_UNLOCK;
3481 #ifndef USE_ITHREADS
3482 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
3485 he = he->refcounted_he_next;
3486 PerlMemShared_free(copy);
3491 =for apidoc m|struct refcounted_he *|refcounted_he_inc|struct refcounted_he *he
3493 Increment the reference count of a C<refcounted_he>. The pointer to the
3494 C<refcounted_he> is also returned. It is safe to pass a null pointer
3495 to this function: no action occurs and a null pointer is returned.
3500 struct refcounted_he *
3501 Perl_refcounted_he_inc(pTHX_ struct refcounted_he *he)
3506 he->refcounted_he_refcnt++;
3507 HINTS_REFCNT_UNLOCK;
3513 =for apidoc cop_fetch_label
3515 Returns the label attached to a cop.
3516 The flags pointer may be set to C<SVf_UTF8> or 0.
3521 /* pp_entereval is aware that labels are stored with a key ':' at the top of
3524 Perl_cop_fetch_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
3525 struct refcounted_he *const chain = cop->cop_hints_hash;
3527 PERL_ARGS_ASSERT_COP_FETCH_LABEL;
3532 if (chain->refcounted_he_keylen != 1)
3534 if (*REF_HE_KEY(chain) != ':')
3537 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3539 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3542 /* Stop anyone trying to really mess us up by adding their own value for
3544 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3545 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3549 *len = chain->refcounted_he_val.refcounted_he_u_len;
3551 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3552 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3554 return chain->refcounted_he_data + 1;
3558 =for apidoc cop_store_label
3560 Save a label into a C<cop_hints_hash>.
3561 You need to set flags to C<SVf_UTF8>
3568 Perl_cop_store_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3572 PERL_ARGS_ASSERT_COP_STORE_LABEL;
3574 if (flags & ~(SVf_UTF8))
3575 Perl_croak(aTHX_ "panic: cop_store_label illegal flag bits 0x%" UVxf,
3577 labelsv = newSVpvn_flags(label, len, SVs_TEMP);
3578 if (flags & SVf_UTF8)
3581 = refcounted_he_new_pvs(cop->cop_hints_hash, ":", labelsv, 0);
3585 =for apidoc hv_assert
3587 Check that a hash is in an internally consistent state.
3595 Perl_hv_assert(pTHX_ HV *hv)
3600 int placeholders = 0;
3603 const I32 riter = HvRITER_get(hv);
3604 HE *eiter = HvEITER_get(hv);
3606 PERL_ARGS_ASSERT_HV_ASSERT;
3608 (void)hv_iterinit(hv);
3610 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3611 /* sanity check the values */
3612 if (HeVAL(entry) == &PL_sv_placeholder)
3616 /* sanity check the keys */
3617 if (HeSVKEY(entry)) {
3618 NOOP; /* Don't know what to check on SV keys. */
3619 } else if (HeKUTF8(entry)) {
3621 if (HeKWASUTF8(entry)) {
3622 PerlIO_printf(Perl_debug_log,
3623 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3624 (int) HeKLEN(entry), HeKEY(entry));
3627 } else if (HeKWASUTF8(entry))
3630 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3631 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3632 const int nhashkeys = HvUSEDKEYS(hv);
3633 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3635 if (nhashkeys != real) {
3636 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3639 if (nhashplaceholders != placeholders) {
3640 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3644 if (withflags && ! HvHASKFLAGS(hv)) {
3645 PerlIO_printf(Perl_debug_log,
3646 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3651 sv_dump(MUTABLE_SV(hv));
3653 HvRITER_set(hv, riter); /* Restore hash iterator state */
3654 HvEITER_set(hv, eiter);
3661 * c-indentation-style: bsd
3663 * indent-tabs-mode: nil
3666 * ex: set ts=8 sts=4 sw=4 et: