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) = SvREFCNT_inc(sv_dup(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) = SvREFCNT_inc(sv_dup(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 xhv->xhv_fill++; /* HvFILL(hv)++ */
821 } else if (xhv->xhv_keys > (IV)xhv->xhv_max) {
823 } else if(!HvREHASH(hv)) {
826 while ((counter = HeNEXT(counter)))
829 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
830 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
831 bucket splits on a rehashed hash, as we're not going to
832 split it again, and if someone is lucky (evil) enough to
833 get all the keys in one list they could exhaust our memory
834 as we repeatedly double the number of buckets on every
835 entry. Linear search feels a less worse thing to do. */
842 return entry ? (void *) &HeVAL(entry) : NULL;
844 return (void *) entry;
848 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
850 const MAGIC *mg = SvMAGIC(hv);
852 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
857 if (isUPPER(mg->mg_type)) {
859 if (mg->mg_type == PERL_MAGIC_tied) {
860 *needs_store = FALSE;
861 return; /* We've set all there is to set. */
864 mg = mg->mg_moremagic;
869 =for apidoc hv_scalar
871 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
877 Perl_hv_scalar(pTHX_ HV *hv)
881 PERL_ARGS_ASSERT_HV_SCALAR;
883 if (SvRMAGICAL(hv)) {
884 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
886 return magic_scalarpack(hv, mg);
890 if (HvFILL((const HV *)hv))
891 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
892 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
900 =for apidoc hv_delete
902 Deletes a key/value pair in the hash. The value SV is removed from the
903 hash and returned to the caller. The C<klen> is the length of the key.
904 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
907 =for apidoc hv_delete_ent
909 Deletes a key/value pair in the hash. The value SV is removed from the
910 hash and returned to the caller. The C<flags> value will normally be zero;
911 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
912 precomputed hash value, or 0 to ask for it to be computed.
918 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
919 int k_flags, I32 d_flags, U32 hash)
924 register HE **oentry;
925 HE *const *first_entry;
926 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
929 if (SvRMAGICAL(hv)) {
932 hv_magic_check (hv, &needs_copy, &needs_store);
936 entry = (HE *) hv_common(hv, keysv, key, klen,
937 k_flags & ~HVhek_FREEKEY,
938 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
940 sv = entry ? HeVAL(entry) : NULL;
946 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
947 /* No longer an element */
948 sv_unmagic(sv, PERL_MAGIC_tiedelem);
951 return NULL; /* element cannot be deleted */
953 #ifdef ENV_IS_CASELESS
954 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
955 /* XXX This code isn't UTF8 clean. */
956 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
957 if (k_flags & HVhek_FREEKEY) {
960 key = strupr(SvPVX(keysv));
969 xhv = (XPVHV*)SvANY(hv);
974 const char * const keysave = key;
975 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
978 k_flags |= HVhek_UTF8;
980 k_flags &= ~HVhek_UTF8;
981 if (key != keysave) {
982 if (k_flags & HVhek_FREEKEY) {
983 /* This shouldn't happen if our caller does what we expect,
984 but strictly the API allows it. */
987 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
989 HvHASKFLAGS_on(MUTABLE_SV(hv));
993 PERL_HASH_INTERNAL(hash, key, klen);
995 if (keysv && (SvIsCOW_shared_hash(keysv))) {
996 hash = SvSHARED_HASH(keysv);
998 PERL_HASH(hash, key, klen);
1002 masked_flags = (k_flags & HVhek_MASK);
1004 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1006 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1008 if (HeHASH(entry) != hash) /* strings can't be equal */
1010 if (HeKLEN(entry) != (I32)klen)
1012 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1014 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1017 if (hv == PL_strtab) {
1018 if (k_flags & HVhek_FREEKEY)
1020 Perl_croak(aTHX_ S_strtab_error, "delete");
1023 /* if placeholder is here, it's already been deleted.... */
1024 if (HeVAL(entry) == &PL_sv_placeholder) {
1025 if (k_flags & HVhek_FREEKEY)
1029 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1030 hv_notallowed(k_flags, key, klen,
1031 "Attempt to delete readonly key '%"SVf"' from"
1032 " a restricted hash");
1034 if (k_flags & HVhek_FREEKEY)
1037 if (d_flags & G_DISCARD)
1040 sv = sv_2mortal(HeVAL(entry));
1041 HeVAL(entry) = &PL_sv_placeholder;
1045 * If a restricted hash, rather than really deleting the entry, put
1046 * a placeholder there. This marks the key as being "approved", so
1047 * we can still access via not-really-existing key without raising
1050 if (SvREADONLY(hv)) {
1051 SvREFCNT_dec(HeVAL(entry));
1052 HeVAL(entry) = &PL_sv_placeholder;
1053 /* We'll be saving this slot, so the number of allocated keys
1054 * doesn't go down, but the number placeholders goes up */
1055 HvPLACEHOLDERS(hv)++;
1057 *oentry = HeNEXT(entry);
1059 xhv->xhv_fill--; /* HvFILL(hv)-- */
1061 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1064 hv_free_ent(hv, entry);
1065 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1066 if (xhv->xhv_keys == 0)
1067 HvHASKFLAGS_off(hv);
1071 if (SvREADONLY(hv)) {
1072 hv_notallowed(k_flags, key, klen,
1073 "Attempt to delete disallowed key '%"SVf"' from"
1074 " a restricted hash");
1077 if (k_flags & HVhek_FREEKEY)
1083 S_hsplit(pTHX_ HV *hv)
1086 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1087 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1088 register I32 newsize = oldsize * 2;
1090 char *a = (char*) HvARRAY(hv);
1092 register HE **oentry;
1093 int longest_chain = 0;
1096 PERL_ARGS_ASSERT_HSPLIT;
1098 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1099 (void*)hv, (int) oldsize);*/
1101 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1102 /* Can make this clear any placeholders first for non-restricted hashes,
1103 even though Storable rebuilds restricted hashes by putting in all the
1104 placeholders (first) before turning on the readonly flag, because
1105 Storable always pre-splits the hash. */
1106 hv_clear_placeholders(hv);
1110 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1111 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1112 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1118 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1121 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1122 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1127 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1129 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1131 if (oldsize >= 64) {
1132 offer_nice_chunk(HvARRAY(hv),
1133 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1134 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1137 Safefree(HvARRAY(hv));
1141 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1142 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1143 HvARRAY(hv) = (HE**) a;
1146 for (i=0; i<oldsize; i++,aep++) {
1147 int left_length = 0;
1148 int right_length = 0;
1152 if (!*aep) /* non-existent */
1155 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1156 if ((HeHASH(entry) & newsize) != (U32)i) {
1157 *oentry = HeNEXT(entry);
1158 HeNEXT(entry) = *bep;
1160 xhv->xhv_fill++; /* HvFILL(hv)++ */
1166 oentry = &HeNEXT(entry);
1170 if (!*aep) /* everything moved */
1171 xhv->xhv_fill--; /* HvFILL(hv)-- */
1172 /* I think we don't actually need to keep track of the longest length,
1173 merely flag if anything is too long. But for the moment while
1174 developing this code I'll track it. */
1175 if (left_length > longest_chain)
1176 longest_chain = left_length;
1177 if (right_length > longest_chain)
1178 longest_chain = right_length;
1182 /* Pick your policy for "hashing isn't working" here: */
1183 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1188 if (hv == PL_strtab) {
1189 /* Urg. Someone is doing something nasty to the string table.
1194 /* Awooga. Awooga. Pathological data. */
1195 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1196 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1199 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1200 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1202 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1205 was_shared = HvSHAREKEYS(hv);
1208 HvSHAREKEYS_off(hv);
1213 for (i=0; i<newsize; i++,aep++) {
1214 register HE *entry = *aep;
1216 /* We're going to trash this HE's next pointer when we chain it
1217 into the new hash below, so store where we go next. */
1218 HE * const next = HeNEXT(entry);
1223 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1228 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1229 hash, HeKFLAGS(entry));
1230 unshare_hek (HeKEY_hek(entry));
1231 HeKEY_hek(entry) = new_hek;
1233 /* Not shared, so simply write the new hash in. */
1234 HeHASH(entry) = hash;
1236 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1237 HEK_REHASH_on(HeKEY_hek(entry));
1238 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1240 /* Copy oentry to the correct new chain. */
1241 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1243 xhv->xhv_fill++; /* HvFILL(hv)++ */
1244 HeNEXT(entry) = *bep;
1250 Safefree (HvARRAY(hv));
1251 HvARRAY(hv) = (HE **)a;
1255 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1258 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1259 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1260 register I32 newsize;
1265 register HE **oentry;
1267 PERL_ARGS_ASSERT_HV_KSPLIT;
1269 newsize = (I32) newmax; /* possible truncation here */
1270 if (newsize != newmax || newmax <= oldsize)
1272 while ((newsize & (1 + ~newsize)) != newsize) {
1273 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1275 if (newsize < newmax)
1277 if (newsize < newmax)
1278 return; /* overflow detection */
1280 a = (char *) HvARRAY(hv);
1283 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1284 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1285 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1291 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1294 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1295 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1300 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1302 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1304 if (oldsize >= 64) {
1305 offer_nice_chunk(HvARRAY(hv),
1306 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1307 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1310 Safefree(HvARRAY(hv));
1313 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1316 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1318 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1319 HvARRAY(hv) = (HE **) a;
1320 if (!xhv->xhv_fill /* !HvFILL(hv) */) /* skip rest if no entries */
1324 for (i=0; i<oldsize; i++,aep++) {
1325 if (!*aep) /* non-existent */
1327 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1328 register I32 j = (HeHASH(entry) & newsize);
1332 *oentry = HeNEXT(entry);
1333 if (!(HeNEXT(entry) = aep[j]))
1334 xhv->xhv_fill++; /* HvFILL(hv)++ */
1339 oentry = &HeNEXT(entry);
1341 if (!*aep) /* everything moved */
1342 xhv->xhv_fill--; /* HvFILL(hv)-- */
1347 Perl_newHVhv(pTHX_ HV *ohv)
1349 HV * const hv = newHV();
1350 STRLEN hv_max, hv_fill;
1352 if (!ohv || (hv_fill = HvFILL(ohv)) == 0)
1354 hv_max = HvMAX(ohv);
1356 if (!SvMAGICAL((const SV *)ohv)) {
1357 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1359 const bool shared = !!HvSHAREKEYS(ohv);
1360 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1362 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1365 /* In each bucket... */
1366 for (i = 0; i <= hv_max; i++) {
1368 HE *oent = oents[i];
1375 /* Copy the linked list of entries. */
1376 for (; oent; oent = HeNEXT(oent)) {
1377 const U32 hash = HeHASH(oent);
1378 const char * const key = HeKEY(oent);
1379 const STRLEN len = HeKLEN(oent);
1380 const int flags = HeKFLAGS(oent);
1381 HE * const ent = new_HE();
1383 HeVAL(ent) = newSVsv(HeVAL(oent));
1385 = shared ? share_hek_flags(key, len, hash, flags)
1386 : save_hek_flags(key, len, hash, flags);
1397 HvFILL(hv) = hv_fill;
1398 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1402 /* Iterate over ohv, copying keys and values one at a time. */
1404 const I32 riter = HvRITER_get(ohv);
1405 HE * const eiter = HvEITER_get(ohv);
1407 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1408 while (hv_max && hv_max + 1 >= hv_fill * 2)
1409 hv_max = hv_max / 2;
1413 while ((entry = hv_iternext_flags(ohv, 0))) {
1414 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1415 newSVsv(HeVAL(entry)), HeHASH(entry),
1418 HvRITER_set(ohv, riter);
1419 HvEITER_set(ohv, eiter);
1425 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1426 magic stays on it. */
1428 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1430 HV * const hv = newHV();
1433 if (ohv && (hv_fill = HvFILL(ohv))) {
1434 STRLEN hv_max = HvMAX(ohv);
1436 const I32 riter = HvRITER_get(ohv);
1437 HE * const eiter = HvEITER_get(ohv);
1439 while (hv_max && hv_max + 1 >= hv_fill * 2)
1440 hv_max = hv_max / 2;
1444 while ((entry = hv_iternext_flags(ohv, 0))) {
1445 SV *const sv = newSVsv(HeVAL(entry));
1446 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1447 (char *)newSVhek (HeKEY_hek(entry)), HEf_SVKEY);
1448 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1449 sv, HeHASH(entry), HeKFLAGS(entry));
1451 HvRITER_set(ohv, riter);
1452 HvEITER_set(ohv, eiter);
1454 hv_magic(hv, NULL, PERL_MAGIC_hints);
1459 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1464 PERL_ARGS_ASSERT_HV_FREE_ENT;
1469 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1470 mro_method_changed_in(hv); /* deletion of method from stash */
1472 if (HeKLEN(entry) == HEf_SVKEY) {
1473 SvREFCNT_dec(HeKEY_sv(entry));
1474 Safefree(HeKEY_hek(entry));
1476 else if (HvSHAREKEYS(hv))
1477 unshare_hek(HeKEY_hek(entry));
1479 Safefree(HeKEY_hek(entry));
1484 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1488 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1492 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1493 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1494 if (HeKLEN(entry) == HEf_SVKEY) {
1495 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1497 hv_free_ent(hv, entry);
1501 =for apidoc hv_clear
1503 Clears a hash, making it empty.
1509 Perl_hv_clear(pTHX_ HV *hv)
1512 register XPVHV* xhv;
1516 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1518 xhv = (XPVHV*)SvANY(hv);
1520 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1521 /* restricted hash: convert all keys to placeholders */
1523 for (i = 0; i <= xhv->xhv_max; i++) {
1524 HE *entry = (HvARRAY(hv))[i];
1525 for (; entry; entry = HeNEXT(entry)) {
1526 /* not already placeholder */
1527 if (HeVAL(entry) != &PL_sv_placeholder) {
1528 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1529 SV* const keysv = hv_iterkeysv(entry);
1531 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1534 SvREFCNT_dec(HeVAL(entry));
1535 HeVAL(entry) = &PL_sv_placeholder;
1536 HvPLACEHOLDERS(hv)++;
1544 HvPLACEHOLDERS_set(hv, 0);
1546 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1549 mg_clear(MUTABLE_SV(hv));
1551 HvHASKFLAGS_off(hv);
1556 mro_isa_changed_in(hv);
1557 HvEITER_set(hv, NULL);
1562 =for apidoc hv_clear_placeholders
1564 Clears any placeholders from a hash. If a restricted hash has any of its keys
1565 marked as readonly and the key is subsequently deleted, the key is not actually
1566 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1567 it so it will be ignored by future operations such as iterating over the hash,
1568 but will still allow the hash to have a value reassigned to the key at some
1569 future point. This function clears any such placeholder keys from the hash.
1570 See Hash::Util::lock_keys() for an example of its use.
1576 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1579 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1581 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1584 clear_placeholders(hv, items);
1588 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1593 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1600 /* Loop down the linked list heads */
1602 HE **oentry = &(HvARRAY(hv))[i];
1605 while ((entry = *oentry)) {
1606 if (HeVAL(entry) == &PL_sv_placeholder) {
1607 *oentry = HeNEXT(entry);
1608 if (first && !*oentry)
1609 HvFILL(hv)--; /* This linked list is now empty. */
1610 if (entry == HvEITER_get(hv))
1613 hv_free_ent(hv, entry);
1617 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1618 if (HvKEYS(hv) == 0)
1619 HvHASKFLAGS_off(hv);
1620 HvPLACEHOLDERS_set(hv, 0);
1624 oentry = &HeNEXT(entry);
1629 /* You can't get here, hence assertion should always fail. */
1630 assert (items == 0);
1635 S_hfreeentries(pTHX_ HV *hv)
1637 /* This is the array that we're going to restore */
1638 HE **const orig_array = HvARRAY(hv);
1642 PERL_ARGS_ASSERT_HFREEENTRIES;
1648 /* If the hash is actually a symbol table with a name, look after the
1650 struct xpvhv_aux *iter = HvAUX(hv);
1652 name = iter->xhv_name;
1653 iter->xhv_name = NULL;
1658 /* orig_array remains unchanged throughout the loop. If after freeing all
1659 the entries it turns out that one of the little blighters has triggered
1660 an action that has caused HvARRAY to be re-allocated, then we set
1661 array to the new HvARRAY, and try again. */
1664 /* This is the one we're going to try to empty. First time round
1665 it's the original array. (Hopefully there will only be 1 time
1667 HE ** const array = HvARRAY(hv);
1670 /* Because we have taken xhv_name out, the only allocated pointer
1671 in the aux structure that might exist is the backreference array.
1676 struct mro_meta *meta;
1677 struct xpvhv_aux *iter = HvAUX(hv);
1678 /* If there are weak references to this HV, we need to avoid
1679 freeing them up here. In particular we need to keep the AV
1680 visible as what we're deleting might well have weak references
1681 back to this HV, so the for loop below may well trigger
1682 the removal of backreferences from this array. */
1684 if (iter->xhv_backreferences) {
1685 /* So donate them to regular backref magic to keep them safe.
1686 The sv_magic will increase the reference count of the AV,
1687 so we need to drop it first. */
1688 SvREFCNT_dec(iter->xhv_backreferences);
1689 if (AvFILLp(iter->xhv_backreferences) == -1) {
1690 /* Turns out that the array is empty. Just free it. */
1691 SvREFCNT_dec(iter->xhv_backreferences);
1694 sv_magic(MUTABLE_SV(hv),
1695 MUTABLE_SV(iter->xhv_backreferences),
1696 PERL_MAGIC_backref, NULL, 0);
1698 iter->xhv_backreferences = NULL;
1701 entry = iter->xhv_eiter; /* HvEITER(hv) */
1702 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1704 hv_free_ent(hv, entry);
1706 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1707 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1709 if((meta = iter->xhv_mro_meta)) {
1710 if (meta->mro_linear_all) {
1711 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1712 meta->mro_linear_all = NULL;
1713 /* This is just acting as a shortcut pointer. */
1714 meta->mro_linear_current = NULL;
1715 } else if (meta->mro_linear_current) {
1716 /* Only the current MRO is stored, so this owns the data.
1718 SvREFCNT_dec(meta->mro_linear_current);
1719 meta->mro_linear_current = NULL;
1721 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1722 SvREFCNT_dec(meta->isa);
1724 iter->xhv_mro_meta = NULL;
1727 /* There are now no allocated pointers in the aux structure. */
1729 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1730 /* What aux structure? */
1733 /* make everyone else think the array is empty, so that the destructors
1734 * called for freed entries can't recusively mess with us */
1737 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1741 /* Loop down the linked list heads */
1742 HE *entry = array[i];
1745 register HE * const oentry = entry;
1746 entry = HeNEXT(entry);
1747 hv_free_ent(hv, oentry);
1751 /* As there are no allocated pointers in the aux structure, it's now
1752 safe to free the array we just cleaned up, if it's not the one we're
1753 going to put back. */
1754 if (array != orig_array) {
1759 /* Good. No-one added anything this time round. */
1764 /* Someone attempted to iterate or set the hash name while we had
1765 the array set to 0. We'll catch backferences on the next time
1766 round the while loop. */
1767 assert(HvARRAY(hv));
1769 if (HvAUX(hv)->xhv_name) {
1770 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1774 if (--attempts == 0) {
1775 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1779 HvARRAY(hv) = orig_array;
1781 /* If the hash was actually a symbol table, put the name back. */
1783 /* We have restored the original array. If name is non-NULL, then
1784 the original array had an aux structure at the end. So this is
1786 SvFLAGS(hv) |= SVf_OOK;
1787 HvAUX(hv)->xhv_name = name;
1792 =for apidoc hv_undef
1800 Perl_hv_undef(pTHX_ HV *hv)
1803 register XPVHV* xhv;
1808 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1809 xhv = (XPVHV*)SvANY(hv);
1811 if ((name = HvNAME_get(hv)) && !PL_dirty)
1812 mro_isa_changed_in(hv);
1817 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1818 hv_name_set(hv, NULL, 0, 0);
1820 SvFLAGS(hv) &= ~SVf_OOK;
1821 Safefree(HvARRAY(hv));
1822 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1824 HvPLACEHOLDERS_set(hv, 0);
1827 mg_clear(MUTABLE_SV(hv));
1830 static struct xpvhv_aux*
1831 S_hv_auxinit(HV *hv) {
1832 struct xpvhv_aux *iter;
1835 PERL_ARGS_ASSERT_HV_AUXINIT;
1838 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1839 + sizeof(struct xpvhv_aux), char);
1841 array = (char *) HvARRAY(hv);
1842 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1843 + sizeof(struct xpvhv_aux), char);
1845 HvARRAY(hv) = (HE**) array;
1846 /* SvOOK_on(hv) attacks the IV flags. */
1847 SvFLAGS(hv) |= SVf_OOK;
1850 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1851 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1853 iter->xhv_backreferences = 0;
1854 iter->xhv_mro_meta = NULL;
1859 =for apidoc hv_iterinit
1861 Prepares a starting point to traverse a hash table. Returns the number of
1862 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1863 currently only meaningful for hashes without tie magic.
1865 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1866 hash buckets that happen to be in use. If you still need that esoteric
1867 value, you can get it through the macro C<HvFILL(tb)>.
1874 Perl_hv_iterinit(pTHX_ HV *hv)
1876 PERL_ARGS_ASSERT_HV_ITERINIT;
1878 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1881 Perl_croak(aTHX_ "Bad hash");
1884 struct xpvhv_aux * const iter = HvAUX(hv);
1885 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1886 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1888 hv_free_ent(hv, entry);
1890 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1891 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1896 /* used to be xhv->xhv_fill before 5.004_65 */
1897 return HvTOTALKEYS(hv);
1901 Perl_hv_riter_p(pTHX_ HV *hv) {
1902 struct xpvhv_aux *iter;
1904 PERL_ARGS_ASSERT_HV_RITER_P;
1907 Perl_croak(aTHX_ "Bad hash");
1909 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1910 return &(iter->xhv_riter);
1914 Perl_hv_eiter_p(pTHX_ HV *hv) {
1915 struct xpvhv_aux *iter;
1917 PERL_ARGS_ASSERT_HV_EITER_P;
1920 Perl_croak(aTHX_ "Bad hash");
1922 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1923 return &(iter->xhv_eiter);
1927 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1928 struct xpvhv_aux *iter;
1930 PERL_ARGS_ASSERT_HV_RITER_SET;
1933 Perl_croak(aTHX_ "Bad hash");
1941 iter = hv_auxinit(hv);
1943 iter->xhv_riter = riter;
1947 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1948 struct xpvhv_aux *iter;
1950 PERL_ARGS_ASSERT_HV_EITER_SET;
1953 Perl_croak(aTHX_ "Bad hash");
1958 /* 0 is the default so don't go malloc()ing a new structure just to
1963 iter = hv_auxinit(hv);
1965 iter->xhv_eiter = eiter;
1969 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1972 struct xpvhv_aux *iter;
1975 PERL_ARGS_ASSERT_HV_NAME_SET;
1976 PERL_UNUSED_ARG(flags);
1979 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
1983 if (iter->xhv_name) {
1984 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
1990 iter = hv_auxinit(hv);
1992 PERL_HASH(hash, name, len);
1993 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
1997 Perl_hv_backreferences_p(pTHX_ HV *hv) {
1998 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2000 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2001 PERL_UNUSED_CONTEXT;
2003 return &(iter->xhv_backreferences);
2007 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2010 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2015 av = HvAUX(hv)->xhv_backreferences;
2018 HvAUX(hv)->xhv_backreferences = 0;
2019 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2025 hv_iternext is implemented as a macro in hv.h
2027 =for apidoc hv_iternext
2029 Returns entries from a hash iterator. See C<hv_iterinit>.
2031 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2032 iterator currently points to, without losing your place or invalidating your
2033 iterator. Note that in this case the current entry is deleted from the hash
2034 with your iterator holding the last reference to it. Your iterator is flagged
2035 to free the entry on the next call to C<hv_iternext>, so you must not discard
2036 your iterator immediately else the entry will leak - call C<hv_iternext> to
2037 trigger the resource deallocation.
2039 =for apidoc hv_iternext_flags
2041 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2042 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2043 set the placeholders keys (for restricted hashes) will be returned in addition
2044 to normal keys. By default placeholders are automatically skipped over.
2045 Currently a placeholder is implemented with a value that is
2046 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2047 restricted hashes may change, and the implementation currently is
2048 insufficiently abstracted for any change to be tidy.
2054 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2057 register XPVHV* xhv;
2061 struct xpvhv_aux *iter;
2063 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2066 Perl_croak(aTHX_ "Bad hash");
2068 xhv = (XPVHV*)SvANY(hv);
2071 /* Too many things (well, pp_each at least) merrily assume that you can
2072 call iv_iternext without calling hv_iterinit, so we'll have to deal
2078 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2079 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2080 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2081 SV * const key = sv_newmortal();
2083 sv_setsv(key, HeSVKEY_force(entry));
2084 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2090 /* one HE per MAGICAL hash */
2091 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2093 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2095 HeKEY_hek(entry) = hek;
2096 HeKLEN(entry) = HEf_SVKEY;
2098 magic_nextpack(MUTABLE_SV(hv),mg,key);
2100 /* force key to stay around until next time */
2101 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2102 return entry; /* beware, hent_val is not set */
2105 SvREFCNT_dec(HeVAL(entry));
2106 Safefree(HeKEY_hek(entry));
2108 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2112 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2113 if (!entry && SvRMAGICAL((const SV *)hv)
2114 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2117 /* The prime_env_iter() on VMS just loaded up new hash values
2118 * so the iteration count needs to be reset back to the beginning
2122 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2127 /* hv_iterint now ensures this. */
2128 assert (HvARRAY(hv));
2130 /* At start of hash, entry is NULL. */
2133 entry = HeNEXT(entry);
2134 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2136 * Skip past any placeholders -- don't want to include them in
2139 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2140 entry = HeNEXT(entry);
2145 /* OK. Come to the end of the current list. Grab the next one. */
2147 iter->xhv_riter++; /* HvRITER(hv)++ */
2148 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2149 /* There is no next one. End of the hash. */
2150 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2153 entry = (HvARRAY(hv))[iter->xhv_riter];
2155 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2156 /* If we have an entry, but it's a placeholder, don't count it.
2158 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2159 entry = HeNEXT(entry);
2161 /* Will loop again if this linked list starts NULL
2162 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2163 or if we run through it and find only placeholders. */
2166 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2168 hv_free_ent(hv, oldentry);
2171 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2172 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2174 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2179 =for apidoc hv_iterkey
2181 Returns the key from the current position of the hash iterator. See
2188 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2190 PERL_ARGS_ASSERT_HV_ITERKEY;
2192 if (HeKLEN(entry) == HEf_SVKEY) {
2194 char * const p = SvPV(HeKEY_sv(entry), len);
2199 *retlen = HeKLEN(entry);
2200 return HeKEY(entry);
2204 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2206 =for apidoc hv_iterkeysv
2208 Returns the key as an C<SV*> from the current position of the hash
2209 iterator. The return value will always be a mortal copy of the key. Also
2216 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2218 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2220 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2224 =for apidoc hv_iterval
2226 Returns the value from the current position of the hash iterator. See
2233 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2235 PERL_ARGS_ASSERT_HV_ITERVAL;
2237 if (SvRMAGICAL(hv)) {
2238 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2239 SV* const sv = sv_newmortal();
2240 if (HeKLEN(entry) == HEf_SVKEY)
2241 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2243 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2247 return HeVAL(entry);
2251 =for apidoc hv_iternextsv
2253 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2260 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2262 HE * const he = hv_iternext_flags(hv, 0);
2264 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2268 *key = hv_iterkey(he, retlen);
2269 return hv_iterval(hv, he);
2276 =for apidoc hv_magic
2278 Adds magic to a hash. See C<sv_magic>.
2283 /* possibly free a shared string if no one has access to it
2284 * len and hash must both be valid for str.
2287 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2289 unshare_hek_or_pvn (NULL, str, len, hash);
2294 Perl_unshare_hek(pTHX_ HEK *hek)
2297 unshare_hek_or_pvn(hek, NULL, 0, 0);
2300 /* possibly free a shared string if no one has access to it
2301 hek if non-NULL takes priority over the other 3, else str, len and hash
2302 are used. If so, len and hash must both be valid for str.
2305 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2308 register XPVHV* xhv;
2310 register HE **oentry;
2312 bool is_utf8 = FALSE;
2314 const char * const save = str;
2315 struct shared_he *he = NULL;
2318 /* Find the shared he which is just before us in memory. */
2319 he = (struct shared_he *)(((char *)hek)
2320 - STRUCT_OFFSET(struct shared_he,
2323 /* Assert that the caller passed us a genuine (or at least consistent)
2325 assert (he->shared_he_he.hent_hek == hek);
2327 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2328 --he->shared_he_he.he_valu.hent_refcount;
2332 hash = HEK_HASH(hek);
2333 } else if (len < 0) {
2334 STRLEN tmplen = -len;
2336 /* See the note in hv_fetch(). --jhi */
2337 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2340 k_flags = HVhek_UTF8;
2342 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2345 /* what follows was the moral equivalent of:
2346 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2348 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2350 xhv = (XPVHV*)SvANY(PL_strtab);
2351 /* assert(xhv_array != 0) */
2352 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2354 const HE *const he_he = &(he->shared_he_he);
2355 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2360 const int flags_masked = k_flags & HVhek_MASK;
2361 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2362 if (HeHASH(entry) != hash) /* strings can't be equal */
2364 if (HeKLEN(entry) != len)
2366 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2368 if (HeKFLAGS(entry) != flags_masked)
2375 if (--entry->he_valu.hent_refcount == 0) {
2376 *oentry = HeNEXT(entry);
2378 /* There are now no entries in our slot. */
2379 xhv->xhv_fill--; /* HvFILL(hv)-- */
2382 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2386 if (!entry && ckWARN_d(WARN_INTERNAL))
2387 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2388 "Attempt to free non-existent shared string '%s'%s"
2390 hek ? HEK_KEY(hek) : str,
2391 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2392 if (k_flags & HVhek_FREEKEY)
2396 /* get a (constant) string ptr from the global string table
2397 * string will get added if it is not already there.
2398 * len and hash must both be valid for str.
2401 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2403 bool is_utf8 = FALSE;
2405 const char * const save = str;
2407 PERL_ARGS_ASSERT_SHARE_HEK;
2410 STRLEN tmplen = -len;
2412 /* See the note in hv_fetch(). --jhi */
2413 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2415 /* If we were able to downgrade here, then than means that we were passed
2416 in a key which only had chars 0-255, but was utf8 encoded. */
2419 /* If we found we were able to downgrade the string to bytes, then
2420 we should flag that it needs upgrading on keys or each. Also flag
2421 that we need share_hek_flags to free the string. */
2423 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2426 return share_hek_flags (str, len, hash, flags);
2430 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2434 const int flags_masked = flags & HVhek_MASK;
2435 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2436 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2438 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2440 /* what follows is the moral equivalent of:
2442 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2443 hv_store(PL_strtab, str, len, NULL, hash);
2445 Can't rehash the shared string table, so not sure if it's worth
2446 counting the number of entries in the linked list
2449 /* assert(xhv_array != 0) */
2450 entry = (HvARRAY(PL_strtab))[hindex];
2451 for (;entry; entry = HeNEXT(entry)) {
2452 if (HeHASH(entry) != hash) /* strings can't be equal */
2454 if (HeKLEN(entry) != len)
2456 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2458 if (HeKFLAGS(entry) != flags_masked)
2464 /* What used to be head of the list.
2465 If this is NULL, then we're the first entry for this slot, which
2466 means we need to increate fill. */
2467 struct shared_he *new_entry;
2470 HE **const head = &HvARRAY(PL_strtab)[hindex];
2471 HE *const next = *head;
2473 /* We don't actually store a HE from the arena and a regular HEK.
2474 Instead we allocate one chunk of memory big enough for both,
2475 and put the HEK straight after the HE. This way we can find the
2476 HEK directly from the HE.
2479 Newx(k, STRUCT_OFFSET(struct shared_he,
2480 shared_he_hek.hek_key[0]) + len + 2, char);
2481 new_entry = (struct shared_he *)k;
2482 entry = &(new_entry->shared_he_he);
2483 hek = &(new_entry->shared_he_hek);
2485 Copy(str, HEK_KEY(hek), len, char);
2486 HEK_KEY(hek)[len] = 0;
2488 HEK_HASH(hek) = hash;
2489 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2491 /* Still "point" to the HEK, so that other code need not know what
2493 HeKEY_hek(entry) = hek;
2494 entry->he_valu.hent_refcount = 0;
2495 HeNEXT(entry) = next;
2498 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2499 if (!next) { /* initial entry? */
2500 xhv->xhv_fill++; /* HvFILL(hv)++ */
2501 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2506 ++entry->he_valu.hent_refcount;
2508 if (flags & HVhek_FREEKEY)
2511 return HeKEY_hek(entry);
2515 Perl_hv_placeholders_p(pTHX_ HV *hv)
2518 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2520 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2523 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2526 Perl_die(aTHX_ "panic: hv_placeholders_p");
2529 return &(mg->mg_len);
2534 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2537 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2539 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2541 return mg ? mg->mg_len : 0;
2545 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2548 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2550 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2555 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2556 Perl_die(aTHX_ "panic: hv_placeholders_set");
2558 /* else we don't need to add magic to record 0 placeholders. */
2562 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2567 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2569 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2574 value = &PL_sv_placeholder;
2577 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2580 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2583 case HVrhek_PV_UTF8:
2584 /* Create a string SV that directly points to the bytes in our
2586 value = newSV_type(SVt_PV);
2587 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2588 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2589 /* This stops anything trying to free it */
2590 SvLEN_set(value, 0);
2592 SvREADONLY_on(value);
2593 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2597 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2598 he->refcounted_he_data[0]);
2604 =for apidoc refcounted_he_chain_2hv
2606 Generates and returns a C<HV *> by walking up the tree starting at the passed
2607 in C<struct refcounted_he *>.
2612 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2616 U32 placeholders = 0;
2617 /* We could chase the chain once to get an idea of the number of keys,
2618 and call ksplit. But for now we'll make a potentially inefficient
2619 hash with only 8 entries in its array. */
2620 const U32 max = HvMAX(hv);
2624 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2625 HvARRAY(hv) = (HE**)array;
2630 U32 hash = chain->refcounted_he_hash;
2632 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2634 HE **oentry = &((HvARRAY(hv))[hash & max]);
2635 HE *entry = *oentry;
2638 for (; entry; entry = HeNEXT(entry)) {
2639 if (HeHASH(entry) == hash) {
2640 /* We might have a duplicate key here. If so, entry is older
2641 than the key we've already put in the hash, so if they are
2642 the same, skip adding entry. */
2644 const STRLEN klen = HeKLEN(entry);
2645 const char *const key = HeKEY(entry);
2646 if (klen == chain->refcounted_he_keylen
2647 && (!!HeKUTF8(entry)
2648 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2649 && memEQ(key, REF_HE_KEY(chain), klen))
2652 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2654 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2655 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2656 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2667 = share_hek_flags(REF_HE_KEY(chain),
2668 chain->refcounted_he_keylen,
2669 chain->refcounted_he_hash,
2670 (chain->refcounted_he_data[0]
2671 & (HVhek_UTF8|HVhek_WASUTF8)));
2673 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2675 value = refcounted_he_value(chain);
2676 if (value == &PL_sv_placeholder)
2678 HeVAL(entry) = value;
2680 /* Link it into the chain. */
2681 HeNEXT(entry) = *oentry;
2682 if (!HeNEXT(entry)) {
2683 /* initial entry. */
2691 chain = chain->refcounted_he_next;
2695 clear_placeholders(hv, placeholders);
2696 HvTOTALKEYS(hv) -= placeholders;
2699 /* We could check in the loop to see if we encounter any keys with key
2700 flags, but it's probably not worth it, as this per-hash flag is only
2701 really meant as an optimisation for things like Storable. */
2703 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2709 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2710 const char *key, STRLEN klen, int flags, U32 hash)
2713 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2714 of your key has to exactly match that which is stored. */
2715 SV *value = &PL_sv_placeholder;
2718 /* No point in doing any of this if there's nothing to find. */
2722 if (flags & HVhek_FREEKEY)
2724 key = SvPV_const(keysv, klen);
2726 is_utf8 = (SvUTF8(keysv) != 0);
2728 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2732 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2733 hash = SvSHARED_HASH(keysv);
2735 PERL_HASH(hash, key, klen);
2739 for (; chain; chain = chain->refcounted_he_next) {
2741 if (hash != chain->refcounted_he_hash)
2743 if (klen != chain->refcounted_he_keylen)
2745 if (memNE(REF_HE_KEY(chain),key,klen))
2747 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2750 if (hash != HEK_HASH(chain->refcounted_he_hek))
2752 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2754 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2756 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2760 value = sv_2mortal(refcounted_he_value(chain));
2765 if (flags & HVhek_FREEKEY)
2772 =for apidoc refcounted_he_new
2774 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2775 stored in a compact form, all references remain the property of the caller.
2776 The C<struct refcounted_he> is returned with a reference count of 1.
2781 struct refcounted_he *
2782 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2783 SV *const key, SV *const value) {
2786 const char *key_p = SvPV_const(key, key_len);
2787 STRLEN value_len = 0;
2788 const char *value_p = NULL;
2791 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2794 value_type = HVrhek_PV;
2795 } else if (SvIOK(value)) {
2796 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2797 } else if (value == &PL_sv_placeholder) {
2798 value_type = HVrhek_delete;
2799 } else if (!SvOK(value)) {
2800 value_type = HVrhek_undef;
2802 value_type = HVrhek_PV;
2805 if (value_type == HVrhek_PV) {
2806 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2807 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2808 value_p = SvPV_const(value, value_len);
2810 value_type = HVrhek_PV_UTF8;
2815 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2816 As we're going to be building hash keys from this value in future,
2817 normalise it now. */
2818 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2819 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2822 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2823 ((value_type == HVrhek_PV
2824 || value_type == HVrhek_PV_UTF8) ?
2825 (void *)value_p : (void *)value),
2829 static struct refcounted_he *
2830 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2831 const char *const key_p, const STRLEN key_len,
2832 const char flags, char value_type,
2833 const void *value, const STRLEN value_len) {
2835 struct refcounted_he *he;
2837 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2838 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2840 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2843 he = (struct refcounted_he*)
2844 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2848 he = (struct refcounted_he*)
2849 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2853 he->refcounted_he_next = parent;
2856 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2857 he->refcounted_he_val.refcounted_he_u_len = value_len;
2858 } else if (value_type == HVrhek_IV) {
2859 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2860 } else if (value_type == HVrhek_UV) {
2861 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2864 PERL_HASH(hash, key_p, key_len);
2867 he->refcounted_he_hash = hash;
2868 he->refcounted_he_keylen = key_len;
2869 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2871 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2874 if (flags & HVhek_WASUTF8) {
2875 /* If it was downgraded from UTF-8, then the pointer returned from
2876 bytes_from_utf8 is an allocated pointer that we must free. */
2880 he->refcounted_he_data[0] = flags;
2881 he->refcounted_he_refcnt = 1;
2887 =for apidoc refcounted_he_free
2889 Decrements the reference count of the passed in C<struct refcounted_he *>
2890 by one. If the reference count reaches zero the structure's memory is freed,
2891 and C<refcounted_he_free> iterates onto the parent node.
2897 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2899 PERL_UNUSED_CONTEXT;
2902 struct refcounted_he *copy;
2906 new_count = --he->refcounted_he_refcnt;
2907 HINTS_REFCNT_UNLOCK;
2913 #ifndef USE_ITHREADS
2914 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2917 he = he->refcounted_he_next;
2918 PerlMemShared_free(copy);
2923 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2928 if (chain->refcounted_he_keylen != 1)
2930 if (*REF_HE_KEY(chain) != ':')
2933 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2935 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2938 /* Stop anyone trying to really mess us up by adding their own value for
2940 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2941 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2945 *len = chain->refcounted_he_val.refcounted_he_u_len;
2947 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2948 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
2950 return chain->refcounted_he_data + 1;
2953 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
2954 that interface. Once it works out how to pass in length and UTF-8 ness, this
2955 function will need superseding. */
2956 struct refcounted_he *
2957 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
2959 PERL_ARGS_ASSERT_STORE_COP_LABEL;
2961 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
2962 label, strlen(label));
2966 =for apidoc hv_assert
2968 Check that a hash is in an internally consistent state.
2976 Perl_hv_assert(pTHX_ HV *hv)
2981 int placeholders = 0;
2984 const I32 riter = HvRITER_get(hv);
2985 HE *eiter = HvEITER_get(hv);
2987 PERL_ARGS_ASSERT_HV_ASSERT;
2989 (void)hv_iterinit(hv);
2991 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
2992 /* sanity check the values */
2993 if (HeVAL(entry) == &PL_sv_placeholder)
2997 /* sanity check the keys */
2998 if (HeSVKEY(entry)) {
2999 NOOP; /* Don't know what to check on SV keys. */
3000 } else if (HeKUTF8(entry)) {
3002 if (HeKWASUTF8(entry)) {
3003 PerlIO_printf(Perl_debug_log,
3004 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3005 (int) HeKLEN(entry), HeKEY(entry));
3008 } else if (HeKWASUTF8(entry))
3011 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3012 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3013 const int nhashkeys = HvUSEDKEYS(hv);
3014 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3016 if (nhashkeys != real) {
3017 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3020 if (nhashplaceholders != placeholders) {
3021 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3025 if (withflags && ! HvHASKFLAGS(hv)) {
3026 PerlIO_printf(Perl_debug_log,
3027 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3032 sv_dump(MUTABLE_SV(hv));
3034 HvRITER_set(hv, riter); /* Restore hash iterator state */
3035 HvEITER_set(hv, eiter);
3042 * c-indentation-style: bsd
3044 * indent-tabs-mode: t
3047 * ex: set ts=8 sts=4 sw=4 noet: