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 HV_MAX_LENGTH_BEFORE_SPLIT 14
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
47 /* We could generate this at compile time via (another) auxiliary C
49 const size_t arena_size = Perl_malloc_good_size(PERL_ARENA_SIZE);
50 HE* he = (HE*) Perl_get_arena(aTHX_ arena_size, HE_SVSLOT);
51 HE * const heend = &he[arena_size / sizeof(HE) - 1];
53 PL_body_roots[HE_SVSLOT] = he;
55 HeNEXT(he) = (HE*)(he + 1);
63 #define new_HE() (HE*)safemalloc(sizeof(HE))
64 #define del_HE(p) safefree((char*)p)
73 void ** const root = &PL_body_roots[HE_SVSLOT];
83 #define new_HE() new_he()
86 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
87 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
103 Newx(k, HEK_BASESIZE + len + 2, char);
105 Copy(str, HEK_KEY(hek), len, char);
106 HEK_KEY(hek)[len] = 0;
108 HEK_HASH(hek) = hash;
109 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
111 if (flags & HVhek_FREEKEY)
116 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
120 Perl_free_tied_hv_pool(pTHX)
123 HE *he = PL_hv_fetch_ent_mh;
126 Safefree(HeKEY_hek(he));
130 PL_hv_fetch_ent_mh = NULL;
133 #if defined(USE_ITHREADS)
135 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
139 PERL_ARGS_ASSERT_HEK_DUP;
140 PERL_UNUSED_ARG(param);
145 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
147 /* We already shared this hash key. */
148 (void)share_hek_hek(shared);
152 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
153 HEK_HASH(source), HEK_FLAGS(source));
154 ptr_table_store(PL_ptr_table, source, shared);
160 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
164 PERL_ARGS_ASSERT_HE_DUP;
168 /* look for it in the table first */
169 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
173 /* create anew and remember what it is */
175 ptr_table_store(PL_ptr_table, e, ret);
177 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
178 if (HeKLEN(e) == HEf_SVKEY) {
180 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
181 HeKEY_hek(ret) = (HEK*)k;
182 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
185 /* This is hek_dup inlined, which seems to be important for speed
187 HEK * const source = HeKEY_hek(e);
188 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
191 /* We already shared this hash key. */
192 (void)share_hek_hek(shared);
196 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
197 HEK_HASH(source), HEK_FLAGS(source));
198 ptr_table_store(PL_ptr_table, source, shared);
200 HeKEY_hek(ret) = shared;
203 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
205 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
208 #endif /* USE_ITHREADS */
211 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
214 SV * const sv = sv_newmortal();
216 PERL_ARGS_ASSERT_HV_NOTALLOWED;
218 if (!(flags & HVhek_FREEKEY)) {
219 sv_setpvn(sv, key, klen);
222 /* Need to free saved eventually assign to mortal SV */
223 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
224 sv_usepvn(sv, (char *) key, klen);
226 if (flags & HVhek_UTF8) {
229 Perl_croak(aTHX_ msg, SVfARG(sv));
232 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
238 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
239 the length of the key. The C<hash> parameter is the precomputed hash
240 value; if it is zero then Perl will compute it. The return value will be
241 NULL if the operation failed or if the value did not need to be actually
242 stored within the hash (as in the case of tied hashes). Otherwise it can
243 be dereferenced to get the original C<SV*>. Note that the caller is
244 responsible for suitably incrementing the reference count of C<val> before
245 the call, and decrementing it if the function returned NULL. Effectively
246 a successful hv_store takes ownership of one reference to C<val>. This is
247 usually what you want; a newly created SV has a reference count of one, so
248 if all your code does is create SVs then store them in a hash, hv_store
249 will own the only reference to the new SV, and your code doesn't need to do
250 anything further to tidy up. hv_store is not implemented as a call to
251 hv_store_ent, and does not create a temporary SV for the key, so if your
252 key data is not already in SV form then use hv_store in preference to
255 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
256 information on how to use this function on tied hashes.
258 =for apidoc hv_store_ent
260 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
261 parameter is the precomputed hash value; if it is zero then Perl will
262 compute it. The return value is the new hash entry so created. It will be
263 NULL if the operation failed or if the value did not need to be actually
264 stored within the hash (as in the case of tied hashes). Otherwise the
265 contents of the return value can be accessed using the C<He?> macros
266 described here. Note that the caller is responsible for suitably
267 incrementing the reference count of C<val> before the call, and
268 decrementing it if the function returned NULL. Effectively a successful
269 hv_store_ent takes ownership of one reference to C<val>. This is
270 usually what you want; a newly created SV has a reference count of one, so
271 if all your code does is create SVs then store them in a hash, hv_store
272 will own the only reference to the new SV, and your code doesn't need to do
273 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
274 unlike C<val> it does not take ownership of it, so maintaining the correct
275 reference count on C<key> is entirely the caller's responsibility. hv_store
276 is not implemented as a call to hv_store_ent, and does not create a temporary
277 SV for the key, so if your key data is not already in SV form then use
278 hv_store in preference to hv_store_ent.
280 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
281 information on how to use this function on tied hashes.
283 =for apidoc hv_exists
285 Returns a boolean indicating whether the specified hash key exists. The
286 C<klen> is the length of the key.
290 Returns the SV which corresponds to the specified key in the hash. The
291 C<klen> is the length of the key. If C<lval> is set then the fetch will be
292 part of a store. Check that the return value is non-null before
293 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 the specified hash key exists. C<hash>
301 can be a valid precomputed hash value, or 0 to ask for it to be
307 /* returns an HE * structure with the all fields set */
308 /* note that hent_val will be a mortal sv for MAGICAL hashes */
310 =for apidoc hv_fetch_ent
312 Returns the hash entry which corresponds to the specified key in the hash.
313 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
314 if you want the function to compute it. IF C<lval> is set then the fetch
315 will be part of a store. Make sure the return value is non-null before
316 accessing it. The return value when C<tb> is a tied hash is a pointer to a
317 static location, so be sure to make a copy of the structure if you need to
320 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
321 information on how to use this function on tied hashes.
326 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
328 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
329 const int action, SV *val, const U32 hash)
334 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
343 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
347 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
348 int flags, int action, SV *val, register U32 hash)
357 const int return_svp = action & HV_FETCH_JUST_SV;
361 if (SvTYPE(hv) == SVTYPEMASK)
364 assert(SvTYPE(hv) == SVt_PVHV);
366 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
368 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
369 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
370 if (uf->uf_set == NULL) {
371 SV* obj = mg->mg_obj;
374 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
375 ((flags & HVhek_UTF8)
379 mg->mg_obj = keysv; /* pass key */
380 uf->uf_index = action; /* pass action */
381 magic_getuvar(MUTABLE_SV(hv), mg);
382 keysv = mg->mg_obj; /* may have changed */
385 /* If the key may have changed, then we need to invalidate
386 any passed-in computed hash value. */
392 if (flags & HVhek_FREEKEY)
394 key = SvPV_const(keysv, klen);
395 is_utf8 = (SvUTF8(keysv) != 0);
396 if (SvIsCOW_shared_hash(keysv)) {
397 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
402 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
405 if (action & HV_DELETE) {
406 return (void *) hv_delete_common(hv, keysv, key, klen,
407 flags | (is_utf8 ? HVhek_UTF8 : 0),
411 xhv = (XPVHV*)SvANY(hv);
413 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
414 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
415 || SvGMAGICAL((const SV *)hv))
417 /* FIXME should be able to skimp on the HE/HEK here when
418 HV_FETCH_JUST_SV is true. */
420 keysv = newSVpvn_utf8(key, klen, is_utf8);
422 keysv = newSVsv(keysv);
425 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
427 /* grab a fake HE/HEK pair from the pool or make a new one */
428 entry = PL_hv_fetch_ent_mh;
430 PL_hv_fetch_ent_mh = HeNEXT(entry);
434 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
435 HeKEY_hek(entry) = (HEK*)k;
437 HeNEXT(entry) = NULL;
438 HeSVKEY_set(entry, keysv);
440 sv_upgrade(sv, SVt_PVLV);
442 /* so we can free entry when freeing sv */
443 LvTARG(sv) = MUTABLE_SV(entry);
445 /* XXX remove at some point? */
446 if (flags & HVhek_FREEKEY)
450 return entry ? (void *) &HeVAL(entry) : NULL;
452 return (void *) entry;
454 #ifdef ENV_IS_CASELESS
455 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
457 for (i = 0; i < klen; ++i)
458 if (isLOWER(key[i])) {
459 /* Would be nice if we had a routine to do the
460 copy and upercase in a single pass through. */
461 const char * const nkey = strupr(savepvn(key,klen));
462 /* Note that this fetch is for nkey (the uppercased
463 key) whereas the store is for key (the original) */
464 void *result = hv_common(hv, NULL, nkey, klen,
465 HVhek_FREEKEY, /* free nkey */
466 0 /* non-LVAL fetch */
467 | HV_DISABLE_UVAR_XKEY
470 0 /* compute hash */);
471 if (!result && (action & HV_FETCH_LVALUE)) {
472 /* This call will free key if necessary.
473 Do it this way to encourage compiler to tail
475 result = hv_common(hv, keysv, key, klen, flags,
477 | HV_DISABLE_UVAR_XKEY
481 if (flags & HVhek_FREEKEY)
489 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
490 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
491 || SvGMAGICAL((const SV *)hv)) {
492 /* I don't understand why hv_exists_ent has svret and sv,
493 whereas hv_exists only had one. */
494 SV * const svret = sv_newmortal();
497 if (keysv || is_utf8) {
499 keysv = newSVpvn_utf8(key, klen, TRUE);
501 keysv = newSVsv(keysv);
503 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
505 mg_copy(MUTABLE_SV(hv), sv, key, klen);
507 if (flags & HVhek_FREEKEY)
509 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
510 /* This cast somewhat evil, but I'm merely using NULL/
511 not NULL to return the boolean exists.
512 And I know hv is not NULL. */
513 return SvTRUE(svret) ? (void *)hv : NULL;
515 #ifdef ENV_IS_CASELESS
516 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
517 /* XXX This code isn't UTF8 clean. */
518 char * const keysave = (char * const)key;
519 /* Will need to free this, so set FREEKEY flag. */
520 key = savepvn(key,klen);
521 key = (const char*)strupr((char*)key);
526 if (flags & HVhek_FREEKEY) {
529 flags |= HVhek_FREEKEY;
533 else if (action & HV_FETCH_ISSTORE) {
536 hv_magic_check (hv, &needs_copy, &needs_store);
538 const bool save_taint = PL_tainted;
539 if (keysv || is_utf8) {
541 keysv = newSVpvn_utf8(key, klen, TRUE);
544 PL_tainted = SvTAINTED(keysv);
545 keysv = sv_2mortal(newSVsv(keysv));
546 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
548 mg_copy(MUTABLE_SV(hv), val, key, klen);
551 TAINT_IF(save_taint);
553 if (flags & HVhek_FREEKEY)
557 #ifdef ENV_IS_CASELESS
558 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
559 /* XXX This code isn't UTF8 clean. */
560 const char *keysave = key;
561 /* Will need to free this, so set FREEKEY flag. */
562 key = savepvn(key,klen);
563 key = (const char*)strupr((char*)key);
568 if (flags & HVhek_FREEKEY) {
571 flags |= HVhek_FREEKEY;
579 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
580 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
581 || (SvRMAGICAL((const SV *)hv)
582 && mg_find((const SV *)hv, PERL_MAGIC_env))
587 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
589 HvARRAY(hv) = (HE**)array;
591 #ifdef DYNAMIC_ENV_FETCH
592 else if (action & HV_FETCH_ISEXISTS) {
593 /* for an %ENV exists, if we do an insert it's by a recursive
594 store call, so avoid creating HvARRAY(hv) right now. */
598 /* XXX remove at some point? */
599 if (flags & HVhek_FREEKEY)
606 if (is_utf8 & !(flags & HVhek_KEYCANONICAL)) {
607 char * const keysave = (char *)key;
608 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
612 flags &= ~HVhek_UTF8;
613 if (key != keysave) {
614 if (flags & HVhek_FREEKEY)
616 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
617 /* If the caller calculated a hash, it was on the sequence of
618 octets that are the UTF-8 form. We've now changed the sequence
619 of octets stored to that of the equivalent byte representation,
620 so the hash we need is different. */
626 PERL_HASH_INTERNAL(hash, key, klen);
627 /* We don't have a pointer to the hv, so we have to replicate the
628 flag into every HEK, so that hv_iterkeysv can see it. */
629 /* And yes, you do need this even though you are not "storing" because
630 you can flip the flags below if doing an lval lookup. (And that
631 was put in to give the semantics Andreas was expecting.) */
632 flags |= HVhek_REHASH;
634 if (keysv && (SvIsCOW_shared_hash(keysv))) {
635 hash = SvSHARED_HASH(keysv);
637 PERL_HASH(hash, key, klen);
641 masked_flags = (flags & HVhek_MASK);
643 #ifdef DYNAMIC_ENV_FETCH
644 if (!HvARRAY(hv)) entry = NULL;
648 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
650 for (; entry; entry = HeNEXT(entry)) {
651 if (HeHASH(entry) != hash) /* strings can't be equal */
653 if (HeKLEN(entry) != (I32)klen)
655 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
657 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
660 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
661 if (HeKFLAGS(entry) != masked_flags) {
662 /* We match if HVhek_UTF8 bit in our flags and hash key's
663 match. But if entry was set previously with HVhek_WASUTF8
664 and key now doesn't (or vice versa) then we should change
665 the key's flag, as this is assignment. */
666 if (HvSHAREKEYS(hv)) {
667 /* Need to swap the key we have for a key with the flags we
668 need. As keys are shared we can't just write to the
669 flag, so we share the new one, unshare the old one. */
670 HEK * const new_hek = share_hek_flags(key, klen, hash,
672 unshare_hek (HeKEY_hek(entry));
673 HeKEY_hek(entry) = new_hek;
675 else if (hv == PL_strtab) {
676 /* PL_strtab is usually the only hash without HvSHAREKEYS,
677 so putting this test here is cheap */
678 if (flags & HVhek_FREEKEY)
680 Perl_croak(aTHX_ S_strtab_error,
681 action & HV_FETCH_LVALUE ? "fetch" : "store");
684 HeKFLAGS(entry) = masked_flags;
685 if (masked_flags & HVhek_ENABLEHVKFLAGS)
688 if (HeVAL(entry) == &PL_sv_placeholder) {
689 /* yes, can store into placeholder slot */
690 if (action & HV_FETCH_LVALUE) {
692 /* This preserves behaviour with the old hv_fetch
693 implementation which at this point would bail out
694 with a break; (at "if we find a placeholder, we
695 pretend we haven't found anything")
697 That break mean that if a placeholder were found, it
698 caused a call into hv_store, which in turn would
699 check magic, and if there is no magic end up pretty
700 much back at this point (in hv_store's code). */
703 /* LVAL fetch which actaully needs a store. */
705 HvPLACEHOLDERS(hv)--;
708 if (val != &PL_sv_placeholder)
709 HvPLACEHOLDERS(hv)--;
712 } else if (action & HV_FETCH_ISSTORE) {
713 SvREFCNT_dec(HeVAL(entry));
716 } else if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* if we find a placeholder, we pretend we haven't found
721 if (flags & HVhek_FREEKEY)
724 return entry ? (void *) &HeVAL(entry) : NULL;
728 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
729 if (!(action & HV_FETCH_ISSTORE)
730 && SvRMAGICAL((const SV *)hv)
731 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
733 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
735 sv = newSVpvn(env,len);
737 return hv_common(hv, keysv, key, klen, flags,
738 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
744 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
745 hv_notallowed(flags, key, klen,
746 "Attempt to access disallowed key '%"SVf"' in"
747 " a restricted hash");
749 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
750 /* Not doing some form of store, so return failure. */
751 if (flags & HVhek_FREEKEY)
755 if (action & HV_FETCH_LVALUE) {
758 /* At this point the old hv_fetch code would call to hv_store,
759 which in turn might do some tied magic. So we need to make that
760 magic check happen. */
761 /* gonna assign to this, so it better be there */
762 /* If a fetch-as-store fails on the fetch, then the action is to
763 recurse once into "hv_store". If we didn't do this, then that
764 recursive call would call the key conversion routine again.
765 However, as we replace the original key with the converted
766 key, this would result in a double conversion, which would show
767 up as a bug if the conversion routine is not idempotent. */
768 return hv_common(hv, keysv, key, klen, flags,
769 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
771 /* XXX Surely that could leak if the fetch-was-store fails?
772 Just like the hv_fetch. */
776 /* Welcome to hv_store... */
779 /* Not sure if we can get here. I think the only case of oentry being
780 NULL is for %ENV with dynamic env fetch. But that should disappear
781 with magic in the previous code. */
784 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
786 HvARRAY(hv) = (HE**)array;
789 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
792 /* share_hek_flags will do the free for us. This might be considered
795 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
796 else if (hv == PL_strtab) {
797 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
798 this test here is cheap */
799 if (flags & HVhek_FREEKEY)
801 Perl_croak(aTHX_ S_strtab_error,
802 action & HV_FETCH_LVALUE ? "fetch" : "store");
804 else /* gotta do the real thing */
805 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
807 HeNEXT(entry) = *oentry;
810 if (val == &PL_sv_placeholder)
811 HvPLACEHOLDERS(hv)++;
812 if (masked_flags & HVhek_ENABLEHVKFLAGS)
816 const HE *counter = HeNEXT(entry);
818 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
819 if (!counter) { /* initial entry? */
820 } else if (xhv->xhv_keys > xhv->xhv_max) {
822 } else if(!HvREHASH(hv)) {
825 while ((counter = HeNEXT(counter)))
828 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
829 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
830 bucket splits on a rehashed hash, as we're not going to
831 split it again, and if someone is lucky (evil) enough to
832 get all the keys in one list they could exhaust our memory
833 as we repeatedly double the number of buckets on every
834 entry. Linear search feels a less worse thing to do. */
841 return entry ? (void *) &HeVAL(entry) : NULL;
843 return (void *) entry;
847 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
849 const MAGIC *mg = SvMAGIC(hv);
851 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
856 if (isUPPER(mg->mg_type)) {
858 if (mg->mg_type == PERL_MAGIC_tied) {
859 *needs_store = FALSE;
860 return; /* We've set all there is to set. */
863 mg = mg->mg_moremagic;
868 =for apidoc hv_scalar
870 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
876 Perl_hv_scalar(pTHX_ HV *hv)
880 PERL_ARGS_ASSERT_HV_SCALAR;
882 if (SvRMAGICAL(hv)) {
883 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
885 return magic_scalarpack(hv, mg);
889 if (HvTOTALKEYS((const HV *)hv))
890 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
891 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
899 =for apidoc hv_delete
901 Deletes a key/value pair in the hash. The value SV is removed from the
902 hash and returned to the caller. The C<klen> is the length of the key.
903 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
906 =for apidoc hv_delete_ent
908 Deletes a key/value pair in the hash. The value SV is removed from the
909 hash and returned to the caller. The C<flags> value will normally be zero;
910 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
911 precomputed hash value, or 0 to ask for it to be computed.
917 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
918 int k_flags, I32 d_flags, U32 hash)
923 register HE **oentry;
924 HE *const *first_entry;
925 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
928 if (SvRMAGICAL(hv)) {
931 hv_magic_check (hv, &needs_copy, &needs_store);
935 entry = (HE *) hv_common(hv, keysv, key, klen,
936 k_flags & ~HVhek_FREEKEY,
937 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
939 sv = entry ? HeVAL(entry) : NULL;
945 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
946 /* No longer an element */
947 sv_unmagic(sv, PERL_MAGIC_tiedelem);
950 return NULL; /* element cannot be deleted */
952 #ifdef ENV_IS_CASELESS
953 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
954 /* XXX This code isn't UTF8 clean. */
955 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
956 if (k_flags & HVhek_FREEKEY) {
959 key = strupr(SvPVX(keysv));
968 xhv = (XPVHV*)SvANY(hv);
973 const char * const keysave = key;
974 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
977 k_flags |= HVhek_UTF8;
979 k_flags &= ~HVhek_UTF8;
980 if (key != keysave) {
981 if (k_flags & HVhek_FREEKEY) {
982 /* This shouldn't happen if our caller does what we expect,
983 but strictly the API allows it. */
986 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
988 HvHASKFLAGS_on(MUTABLE_SV(hv));
992 PERL_HASH_INTERNAL(hash, key, klen);
994 if (keysv && (SvIsCOW_shared_hash(keysv))) {
995 hash = SvSHARED_HASH(keysv);
997 PERL_HASH(hash, key, klen);
1001 masked_flags = (k_flags & HVhek_MASK);
1003 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1005 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1007 if (HeHASH(entry) != hash) /* strings can't be equal */
1009 if (HeKLEN(entry) != (I32)klen)
1011 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1013 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1016 if (hv == PL_strtab) {
1017 if (k_flags & HVhek_FREEKEY)
1019 Perl_croak(aTHX_ S_strtab_error, "delete");
1022 /* if placeholder is here, it's already been deleted.... */
1023 if (HeVAL(entry) == &PL_sv_placeholder) {
1024 if (k_flags & HVhek_FREEKEY)
1028 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1029 hv_notallowed(k_flags, key, klen,
1030 "Attempt to delete readonly key '%"SVf"' from"
1031 " a restricted hash");
1033 if (k_flags & HVhek_FREEKEY)
1036 if (d_flags & G_DISCARD)
1039 sv = sv_2mortal(HeVAL(entry));
1040 HeVAL(entry) = &PL_sv_placeholder;
1044 * If a restricted hash, rather than really deleting the entry, put
1045 * a placeholder there. This marks the key as being "approved", so
1046 * we can still access via not-really-existing key without raising
1049 if (SvREADONLY(hv)) {
1050 SvREFCNT_dec(HeVAL(entry));
1051 HeVAL(entry) = &PL_sv_placeholder;
1052 /* We'll be saving this slot, so the number of allocated keys
1053 * doesn't go down, but the number placeholders goes up */
1054 HvPLACEHOLDERS(hv)++;
1056 *oentry = HeNEXT(entry);
1057 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1060 hv_free_ent(hv, entry);
1061 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1062 if (xhv->xhv_keys == 0)
1063 HvHASKFLAGS_off(hv);
1067 if (SvREADONLY(hv)) {
1068 hv_notallowed(k_flags, key, klen,
1069 "Attempt to delete disallowed key '%"SVf"' from"
1070 " a restricted hash");
1073 if (k_flags & HVhek_FREEKEY)
1079 S_hsplit(pTHX_ HV *hv)
1082 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1083 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1084 register I32 newsize = oldsize * 2;
1086 char *a = (char*) HvARRAY(hv);
1088 int longest_chain = 0;
1091 PERL_ARGS_ASSERT_HSPLIT;
1093 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1094 (void*)hv, (int) oldsize);*/
1096 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1097 /* Can make this clear any placeholders first for non-restricted hashes,
1098 even though Storable rebuilds restricted hashes by putting in all the
1099 placeholders (first) before turning on the readonly flag, because
1100 Storable always pre-splits the hash. */
1101 hv_clear_placeholders(hv);
1105 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1106 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1107 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1113 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1116 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1117 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1122 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1124 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1126 if (oldsize >= 64) {
1127 offer_nice_chunk(HvARRAY(hv),
1128 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1129 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1132 Safefree(HvARRAY(hv));
1136 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1137 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1138 HvARRAY(hv) = (HE**) a;
1141 for (i=0; i<oldsize; i++,aep++) {
1142 int left_length = 0;
1143 int right_length = 0;
1148 if (!entry) /* non-existent */
1152 if ((HeHASH(entry) & newsize) != (U32)i) {
1153 *oentry = HeNEXT(entry);
1154 HeNEXT(entry) = *bep;
1159 oentry = &HeNEXT(entry);
1164 /* I think we don't actually need to keep track of the longest length,
1165 merely flag if anything is too long. But for the moment while
1166 developing this code I'll track it. */
1167 if (left_length > longest_chain)
1168 longest_chain = left_length;
1169 if (right_length > longest_chain)
1170 longest_chain = right_length;
1174 /* Pick your policy for "hashing isn't working" here: */
1175 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1180 if (hv == PL_strtab) {
1181 /* Urg. Someone is doing something nasty to the string table.
1186 /* Awooga. Awooga. Pathological data. */
1187 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1188 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1191 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1192 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1194 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1197 was_shared = HvSHAREKEYS(hv);
1199 HvSHAREKEYS_off(hv);
1204 for (i=0; i<newsize; i++,aep++) {
1205 register HE *entry = *aep;
1207 /* We're going to trash this HE's next pointer when we chain it
1208 into the new hash below, so store where we go next. */
1209 HE * const next = HeNEXT(entry);
1214 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1219 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1220 hash, HeKFLAGS(entry));
1221 unshare_hek (HeKEY_hek(entry));
1222 HeKEY_hek(entry) = new_hek;
1224 /* Not shared, so simply write the new hash in. */
1225 HeHASH(entry) = hash;
1227 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1228 HEK_REHASH_on(HeKEY_hek(entry));
1229 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1231 /* Copy oentry to the correct new chain. */
1232 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1233 HeNEXT(entry) = *bep;
1239 Safefree (HvARRAY(hv));
1240 HvARRAY(hv) = (HE **)a;
1244 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1247 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1248 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1249 register I32 newsize;
1254 PERL_ARGS_ASSERT_HV_KSPLIT;
1256 newsize = (I32) newmax; /* possible truncation here */
1257 if (newsize != newmax || newmax <= oldsize)
1259 while ((newsize & (1 + ~newsize)) != newsize) {
1260 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1262 if (newsize < newmax)
1264 if (newsize < newmax)
1265 return; /* overflow detection */
1267 a = (char *) HvARRAY(hv);
1270 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1271 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1272 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1278 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1281 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1282 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1287 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1289 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1291 if (oldsize >= 64) {
1292 offer_nice_chunk(HvARRAY(hv),
1293 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1294 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1297 Safefree(HvARRAY(hv));
1300 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1303 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1305 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1306 HvARRAY(hv) = (HE **) a;
1307 if (!xhv->xhv_keys /* !HvTOTALKEYS(hv) */) /* skip rest if no entries */
1311 for (i=0; i<oldsize; i++,aep++) {
1315 if (!entry) /* non-existent */
1318 register I32 j = (HeHASH(entry) & newsize);
1322 *oentry = HeNEXT(entry);
1323 HeNEXT(entry) = aep[j];
1327 oentry = &HeNEXT(entry);
1334 Perl_newHVhv(pTHX_ HV *ohv)
1337 HV * const hv = newHV();
1340 if (!ohv || !HvTOTALKEYS(ohv))
1342 hv_max = HvMAX(ohv);
1344 if (!SvMAGICAL((const SV *)ohv)) {
1345 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1347 const bool shared = !!HvSHAREKEYS(ohv);
1348 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1350 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1353 /* In each bucket... */
1354 for (i = 0; i <= hv_max; i++) {
1356 HE *oent = oents[i];
1363 /* Copy the linked list of entries. */
1364 for (; oent; oent = HeNEXT(oent)) {
1365 const U32 hash = HeHASH(oent);
1366 const char * const key = HeKEY(oent);
1367 const STRLEN len = HeKLEN(oent);
1368 const int flags = HeKFLAGS(oent);
1369 HE * const ent = new_HE();
1370 SV *const val = HeVAL(oent);
1372 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1374 = shared ? share_hek_flags(key, len, hash, flags)
1375 : save_hek_flags(key, len, hash, flags);
1386 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1390 /* Iterate over ohv, copying keys and values one at a time. */
1392 const I32 riter = HvRITER_get(ohv);
1393 HE * const eiter = HvEITER_get(ohv);
1394 STRLEN hv_fill = HvFILL(ohv);
1396 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1397 while (hv_max && hv_max + 1 >= hv_fill * 2)
1398 hv_max = hv_max / 2;
1402 while ((entry = hv_iternext_flags(ohv, 0))) {
1403 SV *const val = HeVAL(entry);
1404 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1405 SvIMMORTAL(val) ? val : newSVsv(val),
1406 HeHASH(entry), HeKFLAGS(entry));
1408 HvRITER_set(ohv, riter);
1409 HvEITER_set(ohv, eiter);
1415 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1416 magic stays on it. */
1418 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1420 HV * const hv = newHV();
1422 if (ohv && HvTOTALKEYS(ohv)) {
1423 STRLEN hv_max = HvMAX(ohv);
1424 STRLEN hv_fill = HvFILL(ohv);
1426 const I32 riter = HvRITER_get(ohv);
1427 HE * const eiter = HvEITER_get(ohv);
1429 while (hv_max && hv_max + 1 >= hv_fill * 2)
1430 hv_max = hv_max / 2;
1434 while ((entry = hv_iternext_flags(ohv, 0))) {
1435 SV *const sv = newSVsv(HeVAL(entry));
1436 SV *heksv = newSVhek(HeKEY_hek(entry));
1437 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1438 (char *)heksv, HEf_SVKEY);
1439 SvREFCNT_dec(heksv);
1440 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1441 sv, HeHASH(entry), HeKFLAGS(entry));
1443 HvRITER_set(ohv, riter);
1444 HvEITER_set(ohv, eiter);
1446 hv_magic(hv, NULL, PERL_MAGIC_hints);
1451 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1456 PERL_ARGS_ASSERT_HV_FREE_ENT;
1461 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1462 mro_method_changed_in(hv); /* deletion of method from stash */
1464 if (HeKLEN(entry) == HEf_SVKEY) {
1465 SvREFCNT_dec(HeKEY_sv(entry));
1466 Safefree(HeKEY_hek(entry));
1468 else if (HvSHAREKEYS(hv))
1469 unshare_hek(HeKEY_hek(entry));
1471 Safefree(HeKEY_hek(entry));
1477 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1481 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1485 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1486 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1487 if (HeKLEN(entry) == HEf_SVKEY) {
1488 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1490 hv_free_ent(hv, entry);
1494 =for apidoc hv_clear
1496 Clears a hash, making it empty.
1502 Perl_hv_clear(pTHX_ HV *hv)
1505 register XPVHV* xhv;
1509 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1511 xhv = (XPVHV*)SvANY(hv);
1513 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1514 /* restricted hash: convert all keys to placeholders */
1516 for (i = 0; i <= xhv->xhv_max; i++) {
1517 HE *entry = (HvARRAY(hv))[i];
1518 for (; entry; entry = HeNEXT(entry)) {
1519 /* not already placeholder */
1520 if (HeVAL(entry) != &PL_sv_placeholder) {
1521 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1522 SV* const keysv = hv_iterkeysv(entry);
1524 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1527 SvREFCNT_dec(HeVAL(entry));
1528 HeVAL(entry) = &PL_sv_placeholder;
1529 HvPLACEHOLDERS(hv)++;
1537 HvPLACEHOLDERS_set(hv, 0);
1539 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1542 mg_clear(MUTABLE_SV(hv));
1544 HvHASKFLAGS_off(hv);
1549 mro_isa_changed_in(hv);
1550 HvEITER_set(hv, NULL);
1555 =for apidoc hv_clear_placeholders
1557 Clears any placeholders from a hash. If a restricted hash has any of its keys
1558 marked as readonly and the key is subsequently deleted, the key is not actually
1559 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1560 it so it will be ignored by future operations such as iterating over the hash,
1561 but will still allow the hash to have a value reassigned to the key at some
1562 future point. This function clears any such placeholder keys from the hash.
1563 See Hash::Util::lock_keys() for an example of its use.
1569 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1572 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1574 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1577 clear_placeholders(hv, items);
1581 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1586 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1593 /* Loop down the linked list heads */
1595 HE **oentry = &(HvARRAY(hv))[i];
1598 while ((entry = *oentry)) {
1599 if (HeVAL(entry) == &PL_sv_placeholder) {
1600 *oentry = HeNEXT(entry);
1601 if (entry == HvEITER_get(hv))
1604 hv_free_ent(hv, entry);
1608 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1609 if (HvKEYS(hv) == 0)
1610 HvHASKFLAGS_off(hv);
1611 HvPLACEHOLDERS_set(hv, 0);
1615 oentry = &HeNEXT(entry);
1620 /* You can't get here, hence assertion should always fail. */
1621 assert (items == 0);
1626 S_hfreeentries(pTHX_ HV *hv)
1628 /* This is the array that we're going to restore */
1629 HE **const orig_array = HvARRAY(hv);
1633 PERL_ARGS_ASSERT_HFREEENTRIES;
1639 /* If the hash is actually a symbol table with a name, look after the
1641 struct xpvhv_aux *iter = HvAUX(hv);
1643 name = iter->xhv_name;
1644 iter->xhv_name = NULL;
1649 /* orig_array remains unchanged throughout the loop. If after freeing all
1650 the entries it turns out that one of the little blighters has triggered
1651 an action that has caused HvARRAY to be re-allocated, then we set
1652 array to the new HvARRAY, and try again. */
1655 /* This is the one we're going to try to empty. First time round
1656 it's the original array. (Hopefully there will only be 1 time
1658 HE ** const array = HvARRAY(hv);
1661 /* Because we have taken xhv_name out, the only allocated pointer
1662 in the aux structure that might exist is the backreference array.
1667 struct mro_meta *meta;
1668 struct xpvhv_aux * const iter = HvAUX(hv);
1669 AV *const av = iter->xhv_backreferences;
1672 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
1674 iter->xhv_backreferences = 0;
1677 entry = iter->xhv_eiter; /* HvEITER(hv) */
1678 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1680 hv_free_ent(hv, entry);
1682 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1683 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1685 if((meta = iter->xhv_mro_meta)) {
1686 if (meta->mro_linear_all) {
1687 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1688 meta->mro_linear_all = NULL;
1689 /* This is just acting as a shortcut pointer. */
1690 meta->mro_linear_current = NULL;
1691 } else if (meta->mro_linear_current) {
1692 /* Only the current MRO is stored, so this owns the data.
1694 SvREFCNT_dec(meta->mro_linear_current);
1695 meta->mro_linear_current = NULL;
1697 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1698 SvREFCNT_dec(meta->isa);
1700 iter->xhv_mro_meta = NULL;
1703 /* There are now no allocated pointers in the aux structure. */
1705 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1706 /* What aux structure? */
1709 /* make everyone else think the array is empty, so that the destructors
1710 * called for freed entries can't recursively mess with us */
1712 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1716 /* Loop down the linked list heads */
1717 HE *entry = array[i];
1720 register HE * const oentry = entry;
1721 entry = HeNEXT(entry);
1722 hv_free_ent(hv, oentry);
1726 /* As there are no allocated pointers in the aux structure, it's now
1727 safe to free the array we just cleaned up, if it's not the one we're
1728 going to put back. */
1729 if (array != orig_array) {
1734 /* Good. No-one added anything this time round. */
1739 /* Someone attempted to iterate or set the hash name while we had
1740 the array set to 0. We'll catch backferences on the next time
1741 round the while loop. */
1742 assert(HvARRAY(hv));
1744 if (HvAUX(hv)->xhv_name) {
1745 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1749 if (--attempts == 0) {
1750 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1754 HvARRAY(hv) = orig_array;
1756 /* If the hash was actually a symbol table, put the name back. */
1758 /* We have restored the original array. If name is non-NULL, then
1759 the original array had an aux structure at the end. So this is
1761 SvFLAGS(hv) |= SVf_OOK;
1762 HvAUX(hv)->xhv_name = name;
1767 =for apidoc hv_undef
1775 Perl_hv_undef(pTHX_ HV *hv)
1778 register XPVHV* xhv;
1783 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1784 xhv = (XPVHV*)SvANY(hv);
1786 if ((name = HvNAME_get(hv)) && !PL_dirty)
1787 mro_isa_changed_in(hv);
1792 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1793 hv_name_set(hv, NULL, 0, 0);
1795 SvFLAGS(hv) &= ~SVf_OOK;
1796 Safefree(HvARRAY(hv));
1797 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1799 HvPLACEHOLDERS_set(hv, 0);
1802 mg_clear(MUTABLE_SV(hv));
1808 Returns the number of hash buckets that happen to be in use. This function is
1809 wrapped by the macro C<HvFILL>.
1811 Previously this value was stored in the HV structure, rather than being
1812 calculated on demand.
1818 Perl_hv_fill(pTHX_ HV const *const hv)
1821 HE **ents = HvARRAY(hv);
1823 PERL_ARGS_ASSERT_HV_FILL;
1826 HE *const *const last = ents + HvMAX(hv);
1827 count = last + 1 - ents;
1832 } while (++ents <= last);
1837 static struct xpvhv_aux*
1838 S_hv_auxinit(HV *hv) {
1839 struct xpvhv_aux *iter;
1842 PERL_ARGS_ASSERT_HV_AUXINIT;
1845 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1846 + sizeof(struct xpvhv_aux), char);
1848 array = (char *) HvARRAY(hv);
1849 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1850 + sizeof(struct xpvhv_aux), char);
1852 HvARRAY(hv) = (HE**) array;
1853 /* SvOOK_on(hv) attacks the IV flags. */
1854 SvFLAGS(hv) |= SVf_OOK;
1857 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1858 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1860 iter->xhv_backreferences = 0;
1861 iter->xhv_mro_meta = NULL;
1866 =for apidoc hv_iterinit
1868 Prepares a starting point to traverse a hash table. Returns the number of
1869 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1870 currently only meaningful for hashes without tie magic.
1872 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1873 hash buckets that happen to be in use. If you still need that esoteric
1874 value, you can get it through the macro C<HvFILL(tb)>.
1881 Perl_hv_iterinit(pTHX_ HV *hv)
1883 PERL_ARGS_ASSERT_HV_ITERINIT;
1885 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1888 Perl_croak(aTHX_ "Bad hash");
1891 struct xpvhv_aux * const iter = HvAUX(hv);
1892 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1893 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1895 hv_free_ent(hv, entry);
1897 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1898 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1903 /* used to be xhv->xhv_fill before 5.004_65 */
1904 return HvTOTALKEYS(hv);
1908 Perl_hv_riter_p(pTHX_ HV *hv) {
1909 struct xpvhv_aux *iter;
1911 PERL_ARGS_ASSERT_HV_RITER_P;
1914 Perl_croak(aTHX_ "Bad hash");
1916 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1917 return &(iter->xhv_riter);
1921 Perl_hv_eiter_p(pTHX_ HV *hv) {
1922 struct xpvhv_aux *iter;
1924 PERL_ARGS_ASSERT_HV_EITER_P;
1927 Perl_croak(aTHX_ "Bad hash");
1929 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1930 return &(iter->xhv_eiter);
1934 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1935 struct xpvhv_aux *iter;
1937 PERL_ARGS_ASSERT_HV_RITER_SET;
1940 Perl_croak(aTHX_ "Bad hash");
1948 iter = hv_auxinit(hv);
1950 iter->xhv_riter = riter;
1954 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1955 struct xpvhv_aux *iter;
1957 PERL_ARGS_ASSERT_HV_EITER_SET;
1960 Perl_croak(aTHX_ "Bad hash");
1965 /* 0 is the default so don't go malloc()ing a new structure just to
1970 iter = hv_auxinit(hv);
1972 iter->xhv_eiter = eiter;
1976 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1979 struct xpvhv_aux *iter;
1982 PERL_ARGS_ASSERT_HV_NAME_SET;
1983 PERL_UNUSED_ARG(flags);
1986 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1990 if (iter->xhv_name) {
1991 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1997 iter = hv_auxinit(hv);
1999 PERL_HASH(hash, name, len);
2000 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2004 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2005 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2007 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2008 PERL_UNUSED_CONTEXT;
2010 return &(iter->xhv_backreferences);
2014 hv_iternext is implemented as a macro in hv.h
2016 =for apidoc hv_iternext
2018 Returns entries from a hash iterator. See C<hv_iterinit>.
2020 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2021 iterator currently points to, without losing your place or invalidating your
2022 iterator. Note that in this case the current entry is deleted from the hash
2023 with your iterator holding the last reference to it. Your iterator is flagged
2024 to free the entry on the next call to C<hv_iternext>, so you must not discard
2025 your iterator immediately else the entry will leak - call C<hv_iternext> to
2026 trigger the resource deallocation.
2028 =for apidoc hv_iternext_flags
2030 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2031 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2032 set the placeholders keys (for restricted hashes) will be returned in addition
2033 to normal keys. By default placeholders are automatically skipped over.
2034 Currently a placeholder is implemented with a value that is
2035 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2036 restricted hashes may change, and the implementation currently is
2037 insufficiently abstracted for any change to be tidy.
2043 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2046 register XPVHV* xhv;
2050 struct xpvhv_aux *iter;
2052 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2055 Perl_croak(aTHX_ "Bad hash");
2057 xhv = (XPVHV*)SvANY(hv);
2060 /* Too many things (well, pp_each at least) merrily assume that you can
2061 call iv_iternext without calling hv_iterinit, so we'll have to deal
2067 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2068 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2069 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2070 SV * const key = sv_newmortal();
2072 sv_setsv(key, HeSVKEY_force(entry));
2073 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2079 /* one HE per MAGICAL hash */
2080 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2082 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2084 HeKEY_hek(entry) = hek;
2085 HeKLEN(entry) = HEf_SVKEY;
2087 magic_nextpack(MUTABLE_SV(hv),mg,key);
2089 /* force key to stay around until next time */
2090 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2091 return entry; /* beware, hent_val is not set */
2093 SvREFCNT_dec(HeVAL(entry));
2094 Safefree(HeKEY_hek(entry));
2096 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2100 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2101 if (!entry && SvRMAGICAL((const SV *)hv)
2102 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2105 /* The prime_env_iter() on VMS just loaded up new hash values
2106 * so the iteration count needs to be reset back to the beginning
2110 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2115 /* hv_iterint now ensures this. */
2116 assert (HvARRAY(hv));
2118 /* At start of hash, entry is NULL. */
2121 entry = HeNEXT(entry);
2122 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2124 * Skip past any placeholders -- don't want to include them in
2127 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2128 entry = HeNEXT(entry);
2133 /* Skip the entire loop if the hash is empty. */
2134 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2135 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2137 /* OK. Come to the end of the current list. Grab the next one. */
2139 iter->xhv_riter++; /* HvRITER(hv)++ */
2140 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2141 /* There is no next one. End of the hash. */
2142 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2145 entry = (HvARRAY(hv))[iter->xhv_riter];
2147 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2148 /* If we have an entry, but it's a placeholder, don't count it.
2150 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2151 entry = HeNEXT(entry);
2153 /* Will loop again if this linked list starts NULL
2154 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2155 or if we run through it and find only placeholders. */
2159 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2161 hv_free_ent(hv, oldentry);
2164 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2165 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2167 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2172 =for apidoc hv_iterkey
2174 Returns the key from the current position of the hash iterator. See
2181 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2183 PERL_ARGS_ASSERT_HV_ITERKEY;
2185 if (HeKLEN(entry) == HEf_SVKEY) {
2187 char * const p = SvPV(HeKEY_sv(entry), len);
2192 *retlen = HeKLEN(entry);
2193 return HeKEY(entry);
2197 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2199 =for apidoc hv_iterkeysv
2201 Returns the key as an C<SV*> from the current position of the hash
2202 iterator. The return value will always be a mortal copy of the key. Also
2209 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2211 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2213 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2217 =for apidoc hv_iterval
2219 Returns the value from the current position of the hash iterator. See
2226 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2228 PERL_ARGS_ASSERT_HV_ITERVAL;
2230 if (SvRMAGICAL(hv)) {
2231 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2232 SV* const sv = sv_newmortal();
2233 if (HeKLEN(entry) == HEf_SVKEY)
2234 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2236 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2240 return HeVAL(entry);
2244 =for apidoc hv_iternextsv
2246 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2253 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2255 HE * const he = hv_iternext_flags(hv, 0);
2257 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2261 *key = hv_iterkey(he, retlen);
2262 return hv_iterval(hv, he);
2269 =for apidoc hv_magic
2271 Adds magic to a hash. See C<sv_magic>.
2276 /* possibly free a shared string if no one has access to it
2277 * len and hash must both be valid for str.
2280 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2282 unshare_hek_or_pvn (NULL, str, len, hash);
2287 Perl_unshare_hek(pTHX_ HEK *hek)
2290 unshare_hek_or_pvn(hek, NULL, 0, 0);
2293 /* possibly free a shared string if no one has access to it
2294 hek if non-NULL takes priority over the other 3, else str, len and hash
2295 are used. If so, len and hash must both be valid for str.
2298 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2301 register XPVHV* xhv;
2303 register HE **oentry;
2305 bool is_utf8 = FALSE;
2307 const char * const save = str;
2308 struct shared_he *he = NULL;
2311 /* Find the shared he which is just before us in memory. */
2312 he = (struct shared_he *)(((char *)hek)
2313 - STRUCT_OFFSET(struct shared_he,
2316 /* Assert that the caller passed us a genuine (or at least consistent)
2318 assert (he->shared_he_he.hent_hek == hek);
2320 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2321 --he->shared_he_he.he_valu.hent_refcount;
2325 hash = HEK_HASH(hek);
2326 } else if (len < 0) {
2327 STRLEN tmplen = -len;
2329 /* See the note in hv_fetch(). --jhi */
2330 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2333 k_flags = HVhek_UTF8;
2335 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2338 /* what follows was the moral equivalent of:
2339 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2341 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2343 xhv = (XPVHV*)SvANY(PL_strtab);
2344 /* assert(xhv_array != 0) */
2345 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2347 const HE *const he_he = &(he->shared_he_he);
2348 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2353 const int flags_masked = k_flags & HVhek_MASK;
2354 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2355 if (HeHASH(entry) != hash) /* strings can't be equal */
2357 if (HeKLEN(entry) != len)
2359 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2361 if (HeKFLAGS(entry) != flags_masked)
2368 if (--entry->he_valu.hent_refcount == 0) {
2369 *oentry = HeNEXT(entry);
2371 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2376 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2377 "Attempt to free non-existent shared string '%s'%s"
2379 hek ? HEK_KEY(hek) : str,
2380 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2381 if (k_flags & HVhek_FREEKEY)
2385 /* get a (constant) string ptr from the global string table
2386 * string will get added if it is not already there.
2387 * len and hash must both be valid for str.
2390 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2392 bool is_utf8 = FALSE;
2394 const char * const save = str;
2396 PERL_ARGS_ASSERT_SHARE_HEK;
2399 STRLEN tmplen = -len;
2401 /* See the note in hv_fetch(). --jhi */
2402 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2404 /* If we were able to downgrade here, then than means that we were passed
2405 in a key which only had chars 0-255, but was utf8 encoded. */
2408 /* If we found we were able to downgrade the string to bytes, then
2409 we should flag that it needs upgrading on keys or each. Also flag
2410 that we need share_hek_flags to free the string. */
2412 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2415 return share_hek_flags (str, len, hash, flags);
2419 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2423 const int flags_masked = flags & HVhek_MASK;
2424 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2425 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2427 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2429 /* what follows is the moral equivalent of:
2431 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2432 hv_store(PL_strtab, str, len, NULL, hash);
2434 Can't rehash the shared string table, so not sure if it's worth
2435 counting the number of entries in the linked list
2438 /* assert(xhv_array != 0) */
2439 entry = (HvARRAY(PL_strtab))[hindex];
2440 for (;entry; entry = HeNEXT(entry)) {
2441 if (HeHASH(entry) != hash) /* strings can't be equal */
2443 if (HeKLEN(entry) != len)
2445 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2447 if (HeKFLAGS(entry) != flags_masked)
2453 /* What used to be head of the list.
2454 If this is NULL, then we're the first entry for this slot, which
2455 means we need to increate fill. */
2456 struct shared_he *new_entry;
2459 HE **const head = &HvARRAY(PL_strtab)[hindex];
2460 HE *const next = *head;
2462 /* We don't actually store a HE from the arena and a regular HEK.
2463 Instead we allocate one chunk of memory big enough for both,
2464 and put the HEK straight after the HE. This way we can find the
2465 HEK directly from the HE.
2468 Newx(k, STRUCT_OFFSET(struct shared_he,
2469 shared_he_hek.hek_key[0]) + len + 2, char);
2470 new_entry = (struct shared_he *)k;
2471 entry = &(new_entry->shared_he_he);
2472 hek = &(new_entry->shared_he_hek);
2474 Copy(str, HEK_KEY(hek), len, char);
2475 HEK_KEY(hek)[len] = 0;
2477 HEK_HASH(hek) = hash;
2478 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2480 /* Still "point" to the HEK, so that other code need not know what
2482 HeKEY_hek(entry) = hek;
2483 entry->he_valu.hent_refcount = 0;
2484 HeNEXT(entry) = next;
2487 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2488 if (!next) { /* initial entry? */
2489 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2494 ++entry->he_valu.hent_refcount;
2496 if (flags & HVhek_FREEKEY)
2499 return HeKEY_hek(entry);
2503 Perl_hv_placeholders_p(pTHX_ HV *hv)
2506 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2508 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2511 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2514 Perl_die(aTHX_ "panic: hv_placeholders_p");
2517 return &(mg->mg_len);
2522 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2525 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2527 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2529 return mg ? mg->mg_len : 0;
2533 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2536 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2538 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2543 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2544 Perl_die(aTHX_ "panic: hv_placeholders_set");
2546 /* else we don't need to add magic to record 0 placeholders. */
2550 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2555 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2557 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2562 value = &PL_sv_placeholder;
2565 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2568 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2571 case HVrhek_PV_UTF8:
2572 /* Create a string SV that directly points to the bytes in our
2574 value = newSV_type(SVt_PV);
2575 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2576 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2577 /* This stops anything trying to free it */
2578 SvLEN_set(value, 0);
2580 SvREADONLY_on(value);
2581 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2585 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2586 he->refcounted_he_data[0]);
2592 =for apidoc refcounted_he_chain_2hv
2594 Generates and returns a C<HV *> by walking up the tree starting at the passed
2595 in C<struct refcounted_he *>.
2600 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2604 U32 placeholders = 0;
2605 /* We could chase the chain once to get an idea of the number of keys,
2606 and call ksplit. But for now we'll make a potentially inefficient
2607 hash with only 8 entries in its array. */
2608 const U32 max = HvMAX(hv);
2612 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2613 HvARRAY(hv) = (HE**)array;
2618 U32 hash = chain->refcounted_he_hash;
2620 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2622 HE **oentry = &((HvARRAY(hv))[hash & max]);
2623 HE *entry = *oentry;
2626 for (; entry; entry = HeNEXT(entry)) {
2627 if (HeHASH(entry) == hash) {
2628 /* We might have a duplicate key here. If so, entry is older
2629 than the key we've already put in the hash, so if they are
2630 the same, skip adding entry. */
2632 const STRLEN klen = HeKLEN(entry);
2633 const char *const key = HeKEY(entry);
2634 if (klen == chain->refcounted_he_keylen
2635 && (!!HeKUTF8(entry)
2636 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2637 && memEQ(key, REF_HE_KEY(chain), klen))
2640 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2642 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2643 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2644 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2655 = share_hek_flags(REF_HE_KEY(chain),
2656 chain->refcounted_he_keylen,
2657 chain->refcounted_he_hash,
2658 (chain->refcounted_he_data[0]
2659 & (HVhek_UTF8|HVhek_WASUTF8)));
2661 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2663 value = refcounted_he_value(chain);
2664 if (value == &PL_sv_placeholder)
2666 HeVAL(entry) = value;
2668 /* Link it into the chain. */
2669 HeNEXT(entry) = *oentry;
2675 chain = chain->refcounted_he_next;
2679 clear_placeholders(hv, placeholders);
2680 HvTOTALKEYS(hv) -= placeholders;
2683 /* We could check in the loop to see if we encounter any keys with key
2684 flags, but it's probably not worth it, as this per-hash flag is only
2685 really meant as an optimisation for things like Storable. */
2687 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2693 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2694 const char *key, STRLEN klen, int flags, U32 hash)
2697 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2698 of your key has to exactly match that which is stored. */
2699 SV *value = &PL_sv_placeholder;
2702 /* No point in doing any of this if there's nothing to find. */
2706 if (flags & HVhek_FREEKEY)
2708 key = SvPV_const(keysv, klen);
2710 is_utf8 = (SvUTF8(keysv) != 0);
2712 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2716 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2717 hash = SvSHARED_HASH(keysv);
2719 PERL_HASH(hash, key, klen);
2723 for (; chain; chain = chain->refcounted_he_next) {
2725 if (hash != chain->refcounted_he_hash)
2727 if (klen != chain->refcounted_he_keylen)
2729 if (memNE(REF_HE_KEY(chain),key,klen))
2731 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2734 if (hash != HEK_HASH(chain->refcounted_he_hek))
2736 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2738 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2740 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2744 value = sv_2mortal(refcounted_he_value(chain));
2749 if (flags & HVhek_FREEKEY)
2756 =for apidoc refcounted_he_new
2758 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2759 stored in a compact form, all references remain the property of the caller.
2760 The C<struct refcounted_he> is returned with a reference count of 1.
2765 struct refcounted_he *
2766 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2767 SV *const key, SV *const value) {
2770 const char *key_p = SvPV_const(key, key_len);
2771 STRLEN value_len = 0;
2772 const char *value_p = NULL;
2775 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2778 value_type = HVrhek_PV;
2779 } else if (SvIOK(value)) {
2780 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2781 } else if (value == &PL_sv_placeholder) {
2782 value_type = HVrhek_delete;
2783 } else if (!SvOK(value)) {
2784 value_type = HVrhek_undef;
2786 value_type = HVrhek_PV;
2789 if (value_type == HVrhek_PV) {
2790 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2791 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2792 value_p = SvPV_const(value, value_len);
2794 value_type = HVrhek_PV_UTF8;
2799 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2800 As we're going to be building hash keys from this value in future,
2801 normalise it now. */
2802 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2803 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2806 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2807 ((value_type == HVrhek_PV
2808 || value_type == HVrhek_PV_UTF8) ?
2809 (void *)value_p : (void *)value),
2813 static struct refcounted_he *
2814 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2815 const char *const key_p, const STRLEN key_len,
2816 const char flags, char value_type,
2817 const void *value, const STRLEN value_len) {
2819 struct refcounted_he *he;
2821 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2822 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2824 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2827 he = (struct refcounted_he*)
2828 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2832 he = (struct refcounted_he*)
2833 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2837 he->refcounted_he_next = parent;
2840 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2841 he->refcounted_he_val.refcounted_he_u_len = value_len;
2842 } else if (value_type == HVrhek_IV) {
2843 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2844 } else if (value_type == HVrhek_UV) {
2845 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2848 PERL_HASH(hash, key_p, key_len);
2851 he->refcounted_he_hash = hash;
2852 he->refcounted_he_keylen = key_len;
2853 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2855 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2858 if (flags & HVhek_WASUTF8) {
2859 /* If it was downgraded from UTF-8, then the pointer returned from
2860 bytes_from_utf8 is an allocated pointer that we must free. */
2864 he->refcounted_he_data[0] = flags;
2865 he->refcounted_he_refcnt = 1;
2871 =for apidoc refcounted_he_free
2873 Decrements the reference count of the passed in C<struct refcounted_he *>
2874 by one. If the reference count reaches zero the structure's memory is freed,
2875 and C<refcounted_he_free> iterates onto the parent node.
2881 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2883 PERL_UNUSED_CONTEXT;
2886 struct refcounted_he *copy;
2890 new_count = --he->refcounted_he_refcnt;
2891 HINTS_REFCNT_UNLOCK;
2897 #ifndef USE_ITHREADS
2898 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2901 he = he->refcounted_he_next;
2902 PerlMemShared_free(copy);
2906 /* pp_entereval is aware that labels are stored with a key ':' at the top of
2909 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2914 if (chain->refcounted_he_keylen != 1)
2916 if (*REF_HE_KEY(chain) != ':')
2919 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2921 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2924 /* Stop anyone trying to really mess us up by adding their own value for
2926 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2927 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2931 *len = chain->refcounted_he_val.refcounted_he_u_len;
2933 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2934 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
2936 return chain->refcounted_he_data + 1;
2939 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
2940 that interface. Once it works out how to pass in length and UTF-8 ness, this
2941 function will need superseding. */
2942 struct refcounted_he *
2943 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
2945 PERL_ARGS_ASSERT_STORE_COP_LABEL;
2947 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
2948 label, strlen(label));
2952 =for apidoc hv_assert
2954 Check that a hash is in an internally consistent state.
2962 Perl_hv_assert(pTHX_ HV *hv)
2967 int placeholders = 0;
2970 const I32 riter = HvRITER_get(hv);
2971 HE *eiter = HvEITER_get(hv);
2973 PERL_ARGS_ASSERT_HV_ASSERT;
2975 (void)hv_iterinit(hv);
2977 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2978 /* sanity check the values */
2979 if (HeVAL(entry) == &PL_sv_placeholder)
2983 /* sanity check the keys */
2984 if (HeSVKEY(entry)) {
2985 NOOP; /* Don't know what to check on SV keys. */
2986 } else if (HeKUTF8(entry)) {
2988 if (HeKWASUTF8(entry)) {
2989 PerlIO_printf(Perl_debug_log,
2990 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
2991 (int) HeKLEN(entry), HeKEY(entry));
2994 } else if (HeKWASUTF8(entry))
2997 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
2998 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
2999 const int nhashkeys = HvUSEDKEYS(hv);
3000 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3002 if (nhashkeys != real) {
3003 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3006 if (nhashplaceholders != placeholders) {
3007 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3011 if (withflags && ! HvHASKFLAGS(hv)) {
3012 PerlIO_printf(Perl_debug_log,
3013 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3018 sv_dump(MUTABLE_SV(hv));
3020 HvRITER_set(hv, riter); /* Restore hash iterator state */
3021 HvEITER_set(hv, eiter);
3028 * c-indentation-style: bsd
3030 * indent-tabs-mode: t
3033 * ex: set ts=8 sts=4 sw=4 noet: