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 *iter = HvAUX(hv);
1669 /* weak references: if called from sv_clear(), the backrefs
1670 * should already have been killed; if there are any left, its
1671 * because we're doing hv_clear() or hv_undef(), and the HV
1672 * will continue to live.
1673 * Because while freeing the entries we fake up a NULL HvARRAY
1674 * (and hence HvAUX), we need to store the backref array
1675 * somewhere else; but it still needs to be visible in case
1676 * any the things we free happen to call sv_del_backref().
1677 * We do this by storing it in magic instead.
1678 * If, during the entry freeing, a destructor happens to add
1679 * a new weak backref, then sv_add_backref will look in both
1680 * places (magic in HvAUX) for the AV, but will create a new
1681 * AV in HvAUX if it can't find one (if it finds it in magic,
1682 * it moves it back into HvAUX. So at the end of the iteration
1683 * we have to allow for this. */
1686 if (iter->xhv_backreferences) {
1687 if (SvTYPE(iter->xhv_backreferences) == SVt_PVAV) {
1688 /* The sv_magic will increase the reference count of the AV,
1689 so we need to drop it first. */
1690 SvREFCNT_dec(iter->xhv_backreferences);
1691 if (AvFILLp(iter->xhv_backreferences) == -1) {
1692 /* Turns out that the array is empty. Just free it. */
1693 SvREFCNT_dec(iter->xhv_backreferences);
1696 sv_magic(MUTABLE_SV(hv),
1697 MUTABLE_SV(iter->xhv_backreferences),
1698 PERL_MAGIC_backref, NULL, 0);
1703 sv_magic(MUTABLE_SV(hv), NULL, PERL_MAGIC_backref, NULL, 0);
1704 mg = mg_find(MUTABLE_SV(hv), PERL_MAGIC_backref);
1705 mg->mg_obj = (SV*)iter->xhv_backreferences;
1707 iter->xhv_backreferences = NULL;
1710 entry = iter->xhv_eiter; /* HvEITER(hv) */
1711 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1713 hv_free_ent(hv, entry);
1715 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1716 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1718 if((meta = iter->xhv_mro_meta)) {
1719 if (meta->mro_linear_all) {
1720 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1721 meta->mro_linear_all = NULL;
1722 /* This is just acting as a shortcut pointer. */
1723 meta->mro_linear_current = NULL;
1724 } else if (meta->mro_linear_current) {
1725 /* Only the current MRO is stored, so this owns the data.
1727 SvREFCNT_dec(meta->mro_linear_current);
1728 meta->mro_linear_current = NULL;
1730 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1731 SvREFCNT_dec(meta->isa);
1733 iter->xhv_mro_meta = NULL;
1736 /* There are now no allocated pointers in the aux structure. */
1738 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1739 /* What aux structure? */
1742 /* make everyone else think the array is empty, so that the destructors
1743 * called for freed entries can't recursively mess with us */
1745 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1749 /* Loop down the linked list heads */
1750 HE *entry = array[i];
1753 register HE * const oentry = entry;
1754 entry = HeNEXT(entry);
1755 hv_free_ent(hv, oentry);
1759 /* As there are no allocated pointers in the aux structure, it's now
1760 safe to free the array we just cleaned up, if it's not the one we're
1761 going to put back. */
1762 if (array != orig_array) {
1767 /* Good. No-one added anything this time round. */
1772 /* Someone attempted to iterate or set the hash name while we had
1773 the array set to 0. We'll catch backferences on the next time
1774 round the while loop. */
1775 assert(HvARRAY(hv));
1777 if (HvAUX(hv)->xhv_name) {
1778 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1782 if (--attempts == 0) {
1783 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1787 HvARRAY(hv) = orig_array;
1789 /* If the hash was actually a symbol table, put the name back. */
1791 /* We have restored the original array. If name is non-NULL, then
1792 the original array had an aux structure at the end. So this is
1794 SvFLAGS(hv) |= SVf_OOK;
1795 HvAUX(hv)->xhv_name = name;
1800 =for apidoc hv_undef
1808 Perl_hv_undef(pTHX_ HV *hv)
1811 register XPVHV* xhv;
1816 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1817 xhv = (XPVHV*)SvANY(hv);
1819 if ((name = HvNAME_get(hv)) && !PL_dirty)
1820 mro_isa_changed_in(hv);
1825 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1826 hv_name_set(hv, NULL, 0, 0);
1828 SvFLAGS(hv) &= ~SVf_OOK;
1829 Safefree(HvARRAY(hv));
1830 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1832 HvPLACEHOLDERS_set(hv, 0);
1835 mg_clear(MUTABLE_SV(hv));
1841 Returns the number of hash buckets that happen to be in use. This function is
1842 wrapped by the macro C<HvFILL>.
1844 Previously this value was stored in the HV structure, rather than being
1845 calculated on demand.
1851 Perl_hv_fill(pTHX_ HV const *const hv)
1854 HE **ents = HvARRAY(hv);
1856 PERL_ARGS_ASSERT_HV_FILL;
1859 HE *const *const last = ents + HvMAX(hv);
1860 count = last + 1 - ents;
1865 } while (++ents <= last);
1870 static struct xpvhv_aux*
1871 S_hv_auxinit(HV *hv) {
1872 struct xpvhv_aux *iter;
1875 PERL_ARGS_ASSERT_HV_AUXINIT;
1878 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1879 + sizeof(struct xpvhv_aux), char);
1881 array = (char *) HvARRAY(hv);
1882 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1883 + sizeof(struct xpvhv_aux), char);
1885 HvARRAY(hv) = (HE**) array;
1886 /* SvOOK_on(hv) attacks the IV flags. */
1887 SvFLAGS(hv) |= SVf_OOK;
1890 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1891 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1893 iter->xhv_backreferences = 0;
1894 iter->xhv_mro_meta = NULL;
1899 =for apidoc hv_iterinit
1901 Prepares a starting point to traverse a hash table. Returns the number of
1902 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1903 currently only meaningful for hashes without tie magic.
1905 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1906 hash buckets that happen to be in use. If you still need that esoteric
1907 value, you can get it through the macro C<HvFILL(tb)>.
1914 Perl_hv_iterinit(pTHX_ HV *hv)
1916 PERL_ARGS_ASSERT_HV_ITERINIT;
1918 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1921 Perl_croak(aTHX_ "Bad hash");
1924 struct xpvhv_aux * const iter = HvAUX(hv);
1925 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1926 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1928 hv_free_ent(hv, entry);
1930 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1931 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1936 /* used to be xhv->xhv_fill before 5.004_65 */
1937 return HvTOTALKEYS(hv);
1941 Perl_hv_riter_p(pTHX_ HV *hv) {
1942 struct xpvhv_aux *iter;
1944 PERL_ARGS_ASSERT_HV_RITER_P;
1947 Perl_croak(aTHX_ "Bad hash");
1949 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1950 return &(iter->xhv_riter);
1954 Perl_hv_eiter_p(pTHX_ HV *hv) {
1955 struct xpvhv_aux *iter;
1957 PERL_ARGS_ASSERT_HV_EITER_P;
1960 Perl_croak(aTHX_ "Bad hash");
1962 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1963 return &(iter->xhv_eiter);
1967 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1968 struct xpvhv_aux *iter;
1970 PERL_ARGS_ASSERT_HV_RITER_SET;
1973 Perl_croak(aTHX_ "Bad hash");
1981 iter = hv_auxinit(hv);
1983 iter->xhv_riter = riter;
1987 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1988 struct xpvhv_aux *iter;
1990 PERL_ARGS_ASSERT_HV_EITER_SET;
1993 Perl_croak(aTHX_ "Bad hash");
1998 /* 0 is the default so don't go malloc()ing a new structure just to
2003 iter = hv_auxinit(hv);
2005 iter->xhv_eiter = eiter;
2009 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2012 struct xpvhv_aux *iter;
2015 PERL_ARGS_ASSERT_HV_NAME_SET;
2016 PERL_UNUSED_ARG(flags);
2019 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2023 if (iter->xhv_name) {
2024 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2030 iter = hv_auxinit(hv);
2032 PERL_HASH(hash, name, len);
2033 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2037 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2038 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2040 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2041 PERL_UNUSED_CONTEXT;
2043 return &(iter->xhv_backreferences);
2047 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2050 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2055 av = HvAUX(hv)->xhv_backreferences;
2058 HvAUX(hv)->xhv_backreferences = 0;
2059 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2060 if (SvTYPE(av) == SVt_PVAV)
2066 hv_iternext is implemented as a macro in hv.h
2068 =for apidoc hv_iternext
2070 Returns entries from a hash iterator. See C<hv_iterinit>.
2072 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2073 iterator currently points to, without losing your place or invalidating your
2074 iterator. Note that in this case the current entry is deleted from the hash
2075 with your iterator holding the last reference to it. Your iterator is flagged
2076 to free the entry on the next call to C<hv_iternext>, so you must not discard
2077 your iterator immediately else the entry will leak - call C<hv_iternext> to
2078 trigger the resource deallocation.
2080 =for apidoc hv_iternext_flags
2082 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2083 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2084 set the placeholders keys (for restricted hashes) will be returned in addition
2085 to normal keys. By default placeholders are automatically skipped over.
2086 Currently a placeholder is implemented with a value that is
2087 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2088 restricted hashes may change, and the implementation currently is
2089 insufficiently abstracted for any change to be tidy.
2095 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2098 register XPVHV* xhv;
2102 struct xpvhv_aux *iter;
2104 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2107 Perl_croak(aTHX_ "Bad hash");
2109 xhv = (XPVHV*)SvANY(hv);
2112 /* Too many things (well, pp_each at least) merrily assume that you can
2113 call iv_iternext without calling hv_iterinit, so we'll have to deal
2119 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2120 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2121 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2122 SV * const key = sv_newmortal();
2124 sv_setsv(key, HeSVKEY_force(entry));
2125 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2131 /* one HE per MAGICAL hash */
2132 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2134 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2136 HeKEY_hek(entry) = hek;
2137 HeKLEN(entry) = HEf_SVKEY;
2139 magic_nextpack(MUTABLE_SV(hv),mg,key);
2141 /* force key to stay around until next time */
2142 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2143 return entry; /* beware, hent_val is not set */
2145 SvREFCNT_dec(HeVAL(entry));
2146 Safefree(HeKEY_hek(entry));
2148 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2152 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2153 if (!entry && SvRMAGICAL((const SV *)hv)
2154 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2157 /* The prime_env_iter() on VMS just loaded up new hash values
2158 * so the iteration count needs to be reset back to the beginning
2162 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2167 /* hv_iterint now ensures this. */
2168 assert (HvARRAY(hv));
2170 /* At start of hash, entry is NULL. */
2173 entry = HeNEXT(entry);
2174 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2176 * Skip past any placeholders -- don't want to include them in
2179 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2180 entry = HeNEXT(entry);
2185 /* Skip the entire loop if the hash is empty. */
2186 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2187 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2189 /* OK. Come to the end of the current list. Grab the next one. */
2191 iter->xhv_riter++; /* HvRITER(hv)++ */
2192 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2193 /* There is no next one. End of the hash. */
2194 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2197 entry = (HvARRAY(hv))[iter->xhv_riter];
2199 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2200 /* If we have an entry, but it's a placeholder, don't count it.
2202 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2203 entry = HeNEXT(entry);
2205 /* Will loop again if this linked list starts NULL
2206 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2207 or if we run through it and find only placeholders. */
2211 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2213 hv_free_ent(hv, oldentry);
2216 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2217 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2219 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2224 =for apidoc hv_iterkey
2226 Returns the key from the current position of the hash iterator. See
2233 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2235 PERL_ARGS_ASSERT_HV_ITERKEY;
2237 if (HeKLEN(entry) == HEf_SVKEY) {
2239 char * const p = SvPV(HeKEY_sv(entry), len);
2244 *retlen = HeKLEN(entry);
2245 return HeKEY(entry);
2249 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2251 =for apidoc hv_iterkeysv
2253 Returns the key as an C<SV*> from the current position of the hash
2254 iterator. The return value will always be a mortal copy of the key. Also
2261 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2263 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2265 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2269 =for apidoc hv_iterval
2271 Returns the value from the current position of the hash iterator. See
2278 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2280 PERL_ARGS_ASSERT_HV_ITERVAL;
2282 if (SvRMAGICAL(hv)) {
2283 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2284 SV* const sv = sv_newmortal();
2285 if (HeKLEN(entry) == HEf_SVKEY)
2286 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2288 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2292 return HeVAL(entry);
2296 =for apidoc hv_iternextsv
2298 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2305 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2307 HE * const he = hv_iternext_flags(hv, 0);
2309 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2313 *key = hv_iterkey(he, retlen);
2314 return hv_iterval(hv, he);
2321 =for apidoc hv_magic
2323 Adds magic to a hash. See C<sv_magic>.
2328 /* possibly free a shared string if no one has access to it
2329 * len and hash must both be valid for str.
2332 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2334 unshare_hek_or_pvn (NULL, str, len, hash);
2339 Perl_unshare_hek(pTHX_ HEK *hek)
2342 unshare_hek_or_pvn(hek, NULL, 0, 0);
2345 /* possibly free a shared string if no one has access to it
2346 hek if non-NULL takes priority over the other 3, else str, len and hash
2347 are used. If so, len and hash must both be valid for str.
2350 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2353 register XPVHV* xhv;
2355 register HE **oentry;
2357 bool is_utf8 = FALSE;
2359 const char * const save = str;
2360 struct shared_he *he = NULL;
2363 /* Find the shared he which is just before us in memory. */
2364 he = (struct shared_he *)(((char *)hek)
2365 - STRUCT_OFFSET(struct shared_he,
2368 /* Assert that the caller passed us a genuine (or at least consistent)
2370 assert (he->shared_he_he.hent_hek == hek);
2372 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2373 --he->shared_he_he.he_valu.hent_refcount;
2377 hash = HEK_HASH(hek);
2378 } else if (len < 0) {
2379 STRLEN tmplen = -len;
2381 /* See the note in hv_fetch(). --jhi */
2382 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2385 k_flags = HVhek_UTF8;
2387 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2390 /* what follows was the moral equivalent of:
2391 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2393 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2395 xhv = (XPVHV*)SvANY(PL_strtab);
2396 /* assert(xhv_array != 0) */
2397 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2399 const HE *const he_he = &(he->shared_he_he);
2400 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2405 const int flags_masked = k_flags & HVhek_MASK;
2406 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2407 if (HeHASH(entry) != hash) /* strings can't be equal */
2409 if (HeKLEN(entry) != len)
2411 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2413 if (HeKFLAGS(entry) != flags_masked)
2420 if (--entry->he_valu.hent_refcount == 0) {
2421 *oentry = HeNEXT(entry);
2423 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2428 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2429 "Attempt to free non-existent shared string '%s'%s"
2431 hek ? HEK_KEY(hek) : str,
2432 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2433 if (k_flags & HVhek_FREEKEY)
2437 /* get a (constant) string ptr from the global string table
2438 * string will get added if it is not already there.
2439 * len and hash must both be valid for str.
2442 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2444 bool is_utf8 = FALSE;
2446 const char * const save = str;
2448 PERL_ARGS_ASSERT_SHARE_HEK;
2451 STRLEN tmplen = -len;
2453 /* See the note in hv_fetch(). --jhi */
2454 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2456 /* If we were able to downgrade here, then than means that we were passed
2457 in a key which only had chars 0-255, but was utf8 encoded. */
2460 /* If we found we were able to downgrade the string to bytes, then
2461 we should flag that it needs upgrading on keys or each. Also flag
2462 that we need share_hek_flags to free the string. */
2464 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2467 return share_hek_flags (str, len, hash, flags);
2471 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2475 const int flags_masked = flags & HVhek_MASK;
2476 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2477 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2479 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2481 /* what follows is the moral equivalent of:
2483 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2484 hv_store(PL_strtab, str, len, NULL, hash);
2486 Can't rehash the shared string table, so not sure if it's worth
2487 counting the number of entries in the linked list
2490 /* assert(xhv_array != 0) */
2491 entry = (HvARRAY(PL_strtab))[hindex];
2492 for (;entry; entry = HeNEXT(entry)) {
2493 if (HeHASH(entry) != hash) /* strings can't be equal */
2495 if (HeKLEN(entry) != len)
2497 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2499 if (HeKFLAGS(entry) != flags_masked)
2505 /* What used to be head of the list.
2506 If this is NULL, then we're the first entry for this slot, which
2507 means we need to increate fill. */
2508 struct shared_he *new_entry;
2511 HE **const head = &HvARRAY(PL_strtab)[hindex];
2512 HE *const next = *head;
2514 /* We don't actually store a HE from the arena and a regular HEK.
2515 Instead we allocate one chunk of memory big enough for both,
2516 and put the HEK straight after the HE. This way we can find the
2517 HEK directly from the HE.
2520 Newx(k, STRUCT_OFFSET(struct shared_he,
2521 shared_he_hek.hek_key[0]) + len + 2, char);
2522 new_entry = (struct shared_he *)k;
2523 entry = &(new_entry->shared_he_he);
2524 hek = &(new_entry->shared_he_hek);
2526 Copy(str, HEK_KEY(hek), len, char);
2527 HEK_KEY(hek)[len] = 0;
2529 HEK_HASH(hek) = hash;
2530 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2532 /* Still "point" to the HEK, so that other code need not know what
2534 HeKEY_hek(entry) = hek;
2535 entry->he_valu.hent_refcount = 0;
2536 HeNEXT(entry) = next;
2539 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2540 if (!next) { /* initial entry? */
2541 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2546 ++entry->he_valu.hent_refcount;
2548 if (flags & HVhek_FREEKEY)
2551 return HeKEY_hek(entry);
2555 Perl_hv_placeholders_p(pTHX_ HV *hv)
2558 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2560 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2563 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2566 Perl_die(aTHX_ "panic: hv_placeholders_p");
2569 return &(mg->mg_len);
2574 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2577 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2579 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2581 return mg ? mg->mg_len : 0;
2585 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2588 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2590 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2595 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2596 Perl_die(aTHX_ "panic: hv_placeholders_set");
2598 /* else we don't need to add magic to record 0 placeholders. */
2602 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2607 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2609 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2614 value = &PL_sv_placeholder;
2617 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2620 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2623 case HVrhek_PV_UTF8:
2624 /* Create a string SV that directly points to the bytes in our
2626 value = newSV_type(SVt_PV);
2627 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2628 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2629 /* This stops anything trying to free it */
2630 SvLEN_set(value, 0);
2632 SvREADONLY_on(value);
2633 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2637 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2638 he->refcounted_he_data[0]);
2644 =for apidoc refcounted_he_chain_2hv
2646 Generates and returns a C<HV *> by walking up the tree starting at the passed
2647 in C<struct refcounted_he *>.
2652 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2656 U32 placeholders = 0;
2657 /* We could chase the chain once to get an idea of the number of keys,
2658 and call ksplit. But for now we'll make a potentially inefficient
2659 hash with only 8 entries in its array. */
2660 const U32 max = HvMAX(hv);
2664 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2665 HvARRAY(hv) = (HE**)array;
2670 U32 hash = chain->refcounted_he_hash;
2672 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2674 HE **oentry = &((HvARRAY(hv))[hash & max]);
2675 HE *entry = *oentry;
2678 for (; entry; entry = HeNEXT(entry)) {
2679 if (HeHASH(entry) == hash) {
2680 /* We might have a duplicate key here. If so, entry is older
2681 than the key we've already put in the hash, so if they are
2682 the same, skip adding entry. */
2684 const STRLEN klen = HeKLEN(entry);
2685 const char *const key = HeKEY(entry);
2686 if (klen == chain->refcounted_he_keylen
2687 && (!!HeKUTF8(entry)
2688 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2689 && memEQ(key, REF_HE_KEY(chain), klen))
2692 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2694 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2695 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2696 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2707 = share_hek_flags(REF_HE_KEY(chain),
2708 chain->refcounted_he_keylen,
2709 chain->refcounted_he_hash,
2710 (chain->refcounted_he_data[0]
2711 & (HVhek_UTF8|HVhek_WASUTF8)));
2713 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2715 value = refcounted_he_value(chain);
2716 if (value == &PL_sv_placeholder)
2718 HeVAL(entry) = value;
2720 /* Link it into the chain. */
2721 HeNEXT(entry) = *oentry;
2727 chain = chain->refcounted_he_next;
2731 clear_placeholders(hv, placeholders);
2732 HvTOTALKEYS(hv) -= placeholders;
2735 /* We could check in the loop to see if we encounter any keys with key
2736 flags, but it's probably not worth it, as this per-hash flag is only
2737 really meant as an optimisation for things like Storable. */
2739 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2745 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2746 const char *key, STRLEN klen, int flags, U32 hash)
2749 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2750 of your key has to exactly match that which is stored. */
2751 SV *value = &PL_sv_placeholder;
2754 /* No point in doing any of this if there's nothing to find. */
2758 if (flags & HVhek_FREEKEY)
2760 key = SvPV_const(keysv, klen);
2762 is_utf8 = (SvUTF8(keysv) != 0);
2764 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2768 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2769 hash = SvSHARED_HASH(keysv);
2771 PERL_HASH(hash, key, klen);
2775 for (; chain; chain = chain->refcounted_he_next) {
2777 if (hash != chain->refcounted_he_hash)
2779 if (klen != chain->refcounted_he_keylen)
2781 if (memNE(REF_HE_KEY(chain),key,klen))
2783 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2786 if (hash != HEK_HASH(chain->refcounted_he_hek))
2788 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2790 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2792 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2796 value = sv_2mortal(refcounted_he_value(chain));
2801 if (flags & HVhek_FREEKEY)
2808 =for apidoc refcounted_he_new
2810 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2811 stored in a compact form, all references remain the property of the caller.
2812 The C<struct refcounted_he> is returned with a reference count of 1.
2817 struct refcounted_he *
2818 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2819 SV *const key, SV *const value) {
2822 const char *key_p = SvPV_const(key, key_len);
2823 STRLEN value_len = 0;
2824 const char *value_p = NULL;
2827 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2830 value_type = HVrhek_PV;
2831 } else if (SvIOK(value)) {
2832 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2833 } else if (value == &PL_sv_placeholder) {
2834 value_type = HVrhek_delete;
2835 } else if (!SvOK(value)) {
2836 value_type = HVrhek_undef;
2838 value_type = HVrhek_PV;
2841 if (value_type == HVrhek_PV) {
2842 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2843 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2844 value_p = SvPV_const(value, value_len);
2846 value_type = HVrhek_PV_UTF8;
2851 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2852 As we're going to be building hash keys from this value in future,
2853 normalise it now. */
2854 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2855 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2858 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2859 ((value_type == HVrhek_PV
2860 || value_type == HVrhek_PV_UTF8) ?
2861 (void *)value_p : (void *)value),
2865 static struct refcounted_he *
2866 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2867 const char *const key_p, const STRLEN key_len,
2868 const char flags, char value_type,
2869 const void *value, const STRLEN value_len) {
2871 struct refcounted_he *he;
2873 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2874 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2876 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2879 he = (struct refcounted_he*)
2880 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2884 he = (struct refcounted_he*)
2885 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2889 he->refcounted_he_next = parent;
2892 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2893 he->refcounted_he_val.refcounted_he_u_len = value_len;
2894 } else if (value_type == HVrhek_IV) {
2895 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2896 } else if (value_type == HVrhek_UV) {
2897 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2900 PERL_HASH(hash, key_p, key_len);
2903 he->refcounted_he_hash = hash;
2904 he->refcounted_he_keylen = key_len;
2905 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2907 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2910 if (flags & HVhek_WASUTF8) {
2911 /* If it was downgraded from UTF-8, then the pointer returned from
2912 bytes_from_utf8 is an allocated pointer that we must free. */
2916 he->refcounted_he_data[0] = flags;
2917 he->refcounted_he_refcnt = 1;
2923 =for apidoc refcounted_he_free
2925 Decrements the reference count of the passed in C<struct refcounted_he *>
2926 by one. If the reference count reaches zero the structure's memory is freed,
2927 and C<refcounted_he_free> iterates onto the parent node.
2933 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2935 PERL_UNUSED_CONTEXT;
2938 struct refcounted_he *copy;
2942 new_count = --he->refcounted_he_refcnt;
2943 HINTS_REFCNT_UNLOCK;
2949 #ifndef USE_ITHREADS
2950 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2953 he = he->refcounted_he_next;
2954 PerlMemShared_free(copy);
2958 /* pp_entereval is aware that labels are stored with a key ':' at the top of
2961 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2966 if (chain->refcounted_he_keylen != 1)
2968 if (*REF_HE_KEY(chain) != ':')
2971 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2973 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2976 /* Stop anyone trying to really mess us up by adding their own value for
2978 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2979 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2983 *len = chain->refcounted_he_val.refcounted_he_u_len;
2985 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2986 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
2988 return chain->refcounted_he_data + 1;
2991 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
2992 that interface. Once it works out how to pass in length and UTF-8 ness, this
2993 function will need superseding. */
2994 struct refcounted_he *
2995 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
2997 PERL_ARGS_ASSERT_STORE_COP_LABEL;
2999 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
3000 label, strlen(label));
3004 =for apidoc hv_assert
3006 Check that a hash is in an internally consistent state.
3014 Perl_hv_assert(pTHX_ HV *hv)
3019 int placeholders = 0;
3022 const I32 riter = HvRITER_get(hv);
3023 HE *eiter = HvEITER_get(hv);
3025 PERL_ARGS_ASSERT_HV_ASSERT;
3027 (void)hv_iterinit(hv);
3029 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3030 /* sanity check the values */
3031 if (HeVAL(entry) == &PL_sv_placeholder)
3035 /* sanity check the keys */
3036 if (HeSVKEY(entry)) {
3037 NOOP; /* Don't know what to check on SV keys. */
3038 } else if (HeKUTF8(entry)) {
3040 if (HeKWASUTF8(entry)) {
3041 PerlIO_printf(Perl_debug_log,
3042 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3043 (int) HeKLEN(entry), HeKEY(entry));
3046 } else if (HeKWASUTF8(entry))
3049 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3050 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3051 const int nhashkeys = HvUSEDKEYS(hv);
3052 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3054 if (nhashkeys != real) {
3055 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3058 if (nhashplaceholders != placeholders) {
3059 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3063 if (withflags && ! HvHASKFLAGS(hv)) {
3064 PerlIO_printf(Perl_debug_log,
3065 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3070 sv_dump(MUTABLE_SV(hv));
3072 HvRITER_set(hv, riter); /* Restore hash iterator state */
3073 HvEITER_set(hv, eiter);
3080 * c-indentation-style: bsd
3082 * indent-tabs-mode: t
3085 * ex: set ts=8 sts=4 sw=4 noet: