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 *heksv = newSVhek(HeKEY_hek(entry));
1447 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1448 (char *)heksv, HEf_SVKEY);
1449 SvREFCNT_dec(heksv);
1450 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1451 sv, HeHASH(entry), HeKFLAGS(entry));
1453 HvRITER_set(ohv, riter);
1454 HvEITER_set(ohv, eiter);
1456 hv_magic(hv, NULL, PERL_MAGIC_hints);
1461 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1466 PERL_ARGS_ASSERT_HV_FREE_ENT;
1471 if (HvNAME(hv) && anonymise_cv(HvNAME_HEK(hv), val) && GvCVu(val))
1472 mro_method_changed_in(hv);
1474 if (HeKLEN(entry) == HEf_SVKEY) {
1475 SvREFCNT_dec(HeKEY_sv(entry));
1476 Safefree(HeKEY_hek(entry));
1478 else if (HvSHAREKEYS(hv))
1479 unshare_hek(HeKEY_hek(entry));
1481 Safefree(HeKEY_hek(entry));
1486 S_anonymise_cv(pTHX_ HEK *stash, SV *val)
1490 PERL_ARGS_ASSERT_ANONYMISE_CV;
1492 if (val && isGV(val) && isGV_with_GP(val) && (cv = GvCV(val))) {
1493 if ((SV *)CvGV(cv) == val) {
1497 SV *gvname = newSVhek(stash);
1498 sv_catpvs(gvname, "::__ANON__");
1499 anongv = gv_fetchsv(gvname, GV_ADDMULTI, SVt_PVCV);
1500 SvREFCNT_dec(gvname);
1502 anongv = gv_fetchpvs("__ANON__::__ANON__", GV_ADDMULTI,
1514 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1518 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1522 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1523 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1524 if (HeKLEN(entry) == HEf_SVKEY) {
1525 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1527 hv_free_ent(hv, entry);
1531 =for apidoc hv_clear
1533 Clears a hash, making it empty.
1539 Perl_hv_clear(pTHX_ HV *hv)
1542 register XPVHV* xhv;
1546 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1548 xhv = (XPVHV*)SvANY(hv);
1550 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1551 /* restricted hash: convert all keys to placeholders */
1553 for (i = 0; i <= xhv->xhv_max; i++) {
1554 HE *entry = (HvARRAY(hv))[i];
1555 for (; entry; entry = HeNEXT(entry)) {
1556 /* not already placeholder */
1557 if (HeVAL(entry) != &PL_sv_placeholder) {
1558 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1559 SV* const keysv = hv_iterkeysv(entry);
1561 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1564 SvREFCNT_dec(HeVAL(entry));
1565 HeVAL(entry) = &PL_sv_placeholder;
1566 HvPLACEHOLDERS(hv)++;
1574 HvPLACEHOLDERS_set(hv, 0);
1576 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1579 mg_clear(MUTABLE_SV(hv));
1581 HvHASKFLAGS_off(hv);
1586 mro_isa_changed_in(hv);
1587 HvEITER_set(hv, NULL);
1592 =for apidoc hv_clear_placeholders
1594 Clears any placeholders from a hash. If a restricted hash has any of its keys
1595 marked as readonly and the key is subsequently deleted, the key is not actually
1596 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1597 it so it will be ignored by future operations such as iterating over the hash,
1598 but will still allow the hash to have a value reassigned to the key at some
1599 future point. This function clears any such placeholder keys from the hash.
1600 See Hash::Util::lock_keys() for an example of its use.
1606 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1609 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1611 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1614 clear_placeholders(hv, items);
1618 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1623 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1630 /* Loop down the linked list heads */
1632 HE **oentry = &(HvARRAY(hv))[i];
1635 while ((entry = *oentry)) {
1636 if (HeVAL(entry) == &PL_sv_placeholder) {
1637 *oentry = HeNEXT(entry);
1638 if (first && !*oentry)
1639 HvFILL(hv)--; /* This linked list is now empty. */
1640 if (entry == HvEITER_get(hv))
1643 hv_free_ent(hv, entry);
1647 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1648 if (HvKEYS(hv) == 0)
1649 HvHASKFLAGS_off(hv);
1650 HvPLACEHOLDERS_set(hv, 0);
1654 oentry = &HeNEXT(entry);
1659 /* You can't get here, hence assertion should always fail. */
1660 assert (items == 0);
1665 S_hfreeentries(pTHX_ HV *hv)
1667 /* This is the array that we're going to restore */
1668 HE **const orig_array = HvARRAY(hv);
1672 PERL_ARGS_ASSERT_HFREEENTRIES;
1677 if (HvNAME(hv) && orig_array != NULL) {
1678 /* symbol table: make all the contained subs ANON */
1680 XPVHV *xhv = (XPVHV*)SvANY(hv);
1682 for (i = 0; i <= xhv->xhv_max; i++) {
1683 HE *entry = (HvARRAY(hv))[i];
1684 for (; entry; entry = HeNEXT(entry)) {
1685 SV *val = HeVAL(entry);
1686 /* we need to put the subs in the __ANON__ symtable, as
1687 * this one is being cleared. */
1688 anonymise_cv(NULL, val);
1694 /* If the hash is actually a symbol table with a name, look after the
1696 struct xpvhv_aux *iter = HvAUX(hv);
1698 name = iter->xhv_name;
1699 iter->xhv_name = NULL;
1704 /* orig_array remains unchanged throughout the loop. If after freeing all
1705 the entries it turns out that one of the little blighters has triggered
1706 an action that has caused HvARRAY to be re-allocated, then we set
1707 array to the new HvARRAY, and try again. */
1710 /* This is the one we're going to try to empty. First time round
1711 it's the original array. (Hopefully there will only be 1 time
1713 HE ** const array = HvARRAY(hv);
1716 /* Because we have taken xhv_name out, the only allocated pointer
1717 in the aux structure that might exist is the backreference array.
1722 struct mro_meta *meta;
1723 struct xpvhv_aux *iter = HvAUX(hv);
1724 /* If there are weak references to this HV, we need to avoid
1725 freeing them up here. In particular we need to keep the AV
1726 visible as what we're deleting might well have weak references
1727 back to this HV, so the for loop below may well trigger
1728 the removal of backreferences from this array. */
1730 if (iter->xhv_backreferences) {
1731 /* So donate them to regular backref magic to keep them safe.
1732 The sv_magic will increase the reference count of the AV,
1733 so we need to drop it first. */
1734 SvREFCNT_dec(iter->xhv_backreferences);
1735 if (AvFILLp(iter->xhv_backreferences) == -1) {
1736 /* Turns out that the array is empty. Just free it. */
1737 SvREFCNT_dec(iter->xhv_backreferences);
1740 sv_magic(MUTABLE_SV(hv),
1741 MUTABLE_SV(iter->xhv_backreferences),
1742 PERL_MAGIC_backref, NULL, 0);
1744 iter->xhv_backreferences = NULL;
1747 entry = iter->xhv_eiter; /* HvEITER(hv) */
1748 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1750 hv_free_ent(hv, entry);
1752 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1753 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1755 if((meta = iter->xhv_mro_meta)) {
1756 if (meta->mro_linear_all) {
1757 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1758 meta->mro_linear_all = NULL;
1759 /* This is just acting as a shortcut pointer. */
1760 meta->mro_linear_current = NULL;
1761 } else if (meta->mro_linear_current) {
1762 /* Only the current MRO is stored, so this owns the data.
1764 SvREFCNT_dec(meta->mro_linear_current);
1765 meta->mro_linear_current = NULL;
1767 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1768 SvREFCNT_dec(meta->isa);
1770 iter->xhv_mro_meta = NULL;
1773 /* There are now no allocated pointers in the aux structure. */
1775 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1776 /* What aux structure? */
1779 /* make everyone else think the array is empty, so that the destructors
1780 * called for freed entries can't recusively mess with us */
1783 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1787 /* Loop down the linked list heads */
1788 HE *entry = array[i];
1791 register HE * const oentry = entry;
1792 entry = HeNEXT(entry);
1793 hv_free_ent(hv, oentry);
1797 /* As there are no allocated pointers in the aux structure, it's now
1798 safe to free the array we just cleaned up, if it's not the one we're
1799 going to put back. */
1800 if (array != orig_array) {
1805 /* Good. No-one added anything this time round. */
1810 /* Someone attempted to iterate or set the hash name while we had
1811 the array set to 0. We'll catch backferences on the next time
1812 round the while loop. */
1813 assert(HvARRAY(hv));
1815 if (HvAUX(hv)->xhv_name) {
1816 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1820 if (--attempts == 0) {
1821 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1825 HvARRAY(hv) = orig_array;
1827 /* If the hash was actually a symbol table, put the name back. */
1829 /* We have restored the original array. If name is non-NULL, then
1830 the original array had an aux structure at the end. So this is
1832 SvFLAGS(hv) |= SVf_OOK;
1833 HvAUX(hv)->xhv_name = name;
1838 =for apidoc hv_undef
1846 Perl_hv_undef(pTHX_ HV *hv)
1849 register XPVHV* xhv;
1854 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1855 xhv = (XPVHV*)SvANY(hv);
1857 if ((name = HvNAME_get(hv)) && !PL_dirty)
1858 mro_isa_changed_in(hv);
1863 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1864 hv_name_set(hv, NULL, 0, 0);
1866 SvFLAGS(hv) &= ~SVf_OOK;
1867 Safefree(HvARRAY(hv));
1868 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1870 HvPLACEHOLDERS_set(hv, 0);
1873 mg_clear(MUTABLE_SV(hv));
1876 static struct xpvhv_aux*
1877 S_hv_auxinit(HV *hv) {
1878 struct xpvhv_aux *iter;
1881 PERL_ARGS_ASSERT_HV_AUXINIT;
1884 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1885 + sizeof(struct xpvhv_aux), char);
1887 array = (char *) HvARRAY(hv);
1888 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1889 + sizeof(struct xpvhv_aux), char);
1891 HvARRAY(hv) = (HE**) array;
1892 /* SvOOK_on(hv) attacks the IV flags. */
1893 SvFLAGS(hv) |= SVf_OOK;
1896 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1897 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1899 iter->xhv_backreferences = 0;
1900 iter->xhv_mro_meta = NULL;
1905 =for apidoc hv_iterinit
1907 Prepares a starting point to traverse a hash table. Returns the number of
1908 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1909 currently only meaningful for hashes without tie magic.
1911 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1912 hash buckets that happen to be in use. If you still need that esoteric
1913 value, you can get it through the macro C<HvFILL(tb)>.
1920 Perl_hv_iterinit(pTHX_ HV *hv)
1922 PERL_ARGS_ASSERT_HV_ITERINIT;
1924 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1927 Perl_croak(aTHX_ "Bad hash");
1930 struct xpvhv_aux * const iter = HvAUX(hv);
1931 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1932 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1934 hv_free_ent(hv, entry);
1936 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1937 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1942 /* used to be xhv->xhv_fill before 5.004_65 */
1943 return HvTOTALKEYS(hv);
1947 Perl_hv_riter_p(pTHX_ HV *hv) {
1948 struct xpvhv_aux *iter;
1950 PERL_ARGS_ASSERT_HV_RITER_P;
1953 Perl_croak(aTHX_ "Bad hash");
1955 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1956 return &(iter->xhv_riter);
1960 Perl_hv_eiter_p(pTHX_ HV *hv) {
1961 struct xpvhv_aux *iter;
1963 PERL_ARGS_ASSERT_HV_EITER_P;
1966 Perl_croak(aTHX_ "Bad hash");
1968 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1969 return &(iter->xhv_eiter);
1973 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1974 struct xpvhv_aux *iter;
1976 PERL_ARGS_ASSERT_HV_RITER_SET;
1979 Perl_croak(aTHX_ "Bad hash");
1987 iter = hv_auxinit(hv);
1989 iter->xhv_riter = riter;
1993 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1994 struct xpvhv_aux *iter;
1996 PERL_ARGS_ASSERT_HV_EITER_SET;
1999 Perl_croak(aTHX_ "Bad hash");
2004 /* 0 is the default so don't go malloc()ing a new structure just to
2009 iter = hv_auxinit(hv);
2011 iter->xhv_eiter = eiter;
2015 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2018 struct xpvhv_aux *iter;
2021 PERL_ARGS_ASSERT_HV_NAME_SET;
2022 PERL_UNUSED_ARG(flags);
2025 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2029 if (iter->xhv_name) {
2030 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2036 iter = hv_auxinit(hv);
2038 PERL_HASH(hash, name, len);
2039 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2043 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2044 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2046 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2047 PERL_UNUSED_CONTEXT;
2049 return &(iter->xhv_backreferences);
2053 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2056 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2061 av = HvAUX(hv)->xhv_backreferences;
2064 HvAUX(hv)->xhv_backreferences = 0;
2065 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2071 hv_iternext is implemented as a macro in hv.h
2073 =for apidoc hv_iternext
2075 Returns entries from a hash iterator. See C<hv_iterinit>.
2077 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2078 iterator currently points to, without losing your place or invalidating your
2079 iterator. Note that in this case the current entry is deleted from the hash
2080 with your iterator holding the last reference to it. Your iterator is flagged
2081 to free the entry on the next call to C<hv_iternext>, so you must not discard
2082 your iterator immediately else the entry will leak - call C<hv_iternext> to
2083 trigger the resource deallocation.
2085 =for apidoc hv_iternext_flags
2087 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2088 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2089 set the placeholders keys (for restricted hashes) will be returned in addition
2090 to normal keys. By default placeholders are automatically skipped over.
2091 Currently a placeholder is implemented with a value that is
2092 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2093 restricted hashes may change, and the implementation currently is
2094 insufficiently abstracted for any change to be tidy.
2100 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2103 register XPVHV* xhv;
2107 struct xpvhv_aux *iter;
2109 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2112 Perl_croak(aTHX_ "Bad hash");
2114 xhv = (XPVHV*)SvANY(hv);
2117 /* Too many things (well, pp_each at least) merrily assume that you can
2118 call iv_iternext without calling hv_iterinit, so we'll have to deal
2124 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2125 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2126 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2127 SV * const key = sv_newmortal();
2129 sv_setsv(key, HeSVKEY_force(entry));
2130 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2136 /* one HE per MAGICAL hash */
2137 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2139 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2141 HeKEY_hek(entry) = hek;
2142 HeKLEN(entry) = HEf_SVKEY;
2144 magic_nextpack(MUTABLE_SV(hv),mg,key);
2146 /* force key to stay around until next time */
2147 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2148 return entry; /* beware, hent_val is not set */
2151 SvREFCNT_dec(HeVAL(entry));
2152 Safefree(HeKEY_hek(entry));
2154 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2158 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2159 if (!entry && SvRMAGICAL((const SV *)hv)
2160 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2163 /* The prime_env_iter() on VMS just loaded up new hash values
2164 * so the iteration count needs to be reset back to the beginning
2168 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2173 /* hv_iterint now ensures this. */
2174 assert (HvARRAY(hv));
2176 /* At start of hash, entry is NULL. */
2179 entry = HeNEXT(entry);
2180 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2182 * Skip past any placeholders -- don't want to include them in
2185 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2186 entry = HeNEXT(entry);
2191 /* Skip the entire loop if the hash is empty. */
2192 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2193 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2195 /* OK. Come to the end of the current list. Grab the next one. */
2197 iter->xhv_riter++; /* HvRITER(hv)++ */
2198 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2199 /* There is no next one. End of the hash. */
2200 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2203 entry = (HvARRAY(hv))[iter->xhv_riter];
2205 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2206 /* If we have an entry, but it's a placeholder, don't count it.
2208 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2209 entry = HeNEXT(entry);
2211 /* Will loop again if this linked list starts NULL
2212 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2213 or if we run through it and find only placeholders. */
2217 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2219 hv_free_ent(hv, oldentry);
2222 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2223 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2225 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2230 =for apidoc hv_iterkey
2232 Returns the key from the current position of the hash iterator. See
2239 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2241 PERL_ARGS_ASSERT_HV_ITERKEY;
2243 if (HeKLEN(entry) == HEf_SVKEY) {
2245 char * const p = SvPV(HeKEY_sv(entry), len);
2250 *retlen = HeKLEN(entry);
2251 return HeKEY(entry);
2255 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2257 =for apidoc hv_iterkeysv
2259 Returns the key as an C<SV*> from the current position of the hash
2260 iterator. The return value will always be a mortal copy of the key. Also
2267 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2269 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2271 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2275 =for apidoc hv_iterval
2277 Returns the value from the current position of the hash iterator. See
2284 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2286 PERL_ARGS_ASSERT_HV_ITERVAL;
2288 if (SvRMAGICAL(hv)) {
2289 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2290 SV* const sv = sv_newmortal();
2291 if (HeKLEN(entry) == HEf_SVKEY)
2292 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2294 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2298 return HeVAL(entry);
2302 =for apidoc hv_iternextsv
2304 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2311 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2313 HE * const he = hv_iternext_flags(hv, 0);
2315 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2319 *key = hv_iterkey(he, retlen);
2320 return hv_iterval(hv, he);
2327 =for apidoc hv_magic
2329 Adds magic to a hash. See C<sv_magic>.
2334 /* possibly free a shared string if no one has access to it
2335 * len and hash must both be valid for str.
2338 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2340 unshare_hek_or_pvn (NULL, str, len, hash);
2345 Perl_unshare_hek(pTHX_ HEK *hek)
2348 unshare_hek_or_pvn(hek, NULL, 0, 0);
2351 /* possibly free a shared string if no one has access to it
2352 hek if non-NULL takes priority over the other 3, else str, len and hash
2353 are used. If so, len and hash must both be valid for str.
2356 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2359 register XPVHV* xhv;
2361 register HE **oentry;
2363 bool is_utf8 = FALSE;
2365 const char * const save = str;
2366 struct shared_he *he = NULL;
2369 /* Find the shared he which is just before us in memory. */
2370 he = (struct shared_he *)(((char *)hek)
2371 - STRUCT_OFFSET(struct shared_he,
2374 /* Assert that the caller passed us a genuine (or at least consistent)
2376 assert (he->shared_he_he.hent_hek == hek);
2378 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2379 --he->shared_he_he.he_valu.hent_refcount;
2383 hash = HEK_HASH(hek);
2384 } else if (len < 0) {
2385 STRLEN tmplen = -len;
2387 /* See the note in hv_fetch(). --jhi */
2388 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2391 k_flags = HVhek_UTF8;
2393 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2396 /* what follows was the moral equivalent of:
2397 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2399 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2401 xhv = (XPVHV*)SvANY(PL_strtab);
2402 /* assert(xhv_array != 0) */
2403 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2405 const HE *const he_he = &(he->shared_he_he);
2406 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2411 const int flags_masked = k_flags & HVhek_MASK;
2412 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2413 if (HeHASH(entry) != hash) /* strings can't be equal */
2415 if (HeKLEN(entry) != len)
2417 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2419 if (HeKFLAGS(entry) != flags_masked)
2426 if (--entry->he_valu.hent_refcount == 0) {
2427 *oentry = HeNEXT(entry);
2429 /* There are now no entries in our slot. */
2430 xhv->xhv_fill--; /* HvFILL(hv)-- */
2433 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2437 if (!entry && ckWARN_d(WARN_INTERNAL))
2438 Perl_warner(aTHX_ packWARN(WARN_INTERNAL),
2439 "Attempt to free non-existent shared string '%s'%s"
2441 hek ? HEK_KEY(hek) : str,
2442 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2443 if (k_flags & HVhek_FREEKEY)
2447 /* get a (constant) string ptr from the global string table
2448 * string will get added if it is not already there.
2449 * len and hash must both be valid for str.
2452 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2454 bool is_utf8 = FALSE;
2456 const char * const save = str;
2458 PERL_ARGS_ASSERT_SHARE_HEK;
2461 STRLEN tmplen = -len;
2463 /* See the note in hv_fetch(). --jhi */
2464 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2466 /* If we were able to downgrade here, then than means that we were passed
2467 in a key which only had chars 0-255, but was utf8 encoded. */
2470 /* If we found we were able to downgrade the string to bytes, then
2471 we should flag that it needs upgrading on keys or each. Also flag
2472 that we need share_hek_flags to free the string. */
2474 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2477 return share_hek_flags (str, len, hash, flags);
2481 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2485 const int flags_masked = flags & HVhek_MASK;
2486 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2487 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2489 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2491 /* what follows is the moral equivalent of:
2493 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2494 hv_store(PL_strtab, str, len, NULL, hash);
2496 Can't rehash the shared string table, so not sure if it's worth
2497 counting the number of entries in the linked list
2500 /* assert(xhv_array != 0) */
2501 entry = (HvARRAY(PL_strtab))[hindex];
2502 for (;entry; entry = HeNEXT(entry)) {
2503 if (HeHASH(entry) != hash) /* strings can't be equal */
2505 if (HeKLEN(entry) != len)
2507 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2509 if (HeKFLAGS(entry) != flags_masked)
2515 /* What used to be head of the list.
2516 If this is NULL, then we're the first entry for this slot, which
2517 means we need to increate fill. */
2518 struct shared_he *new_entry;
2521 HE **const head = &HvARRAY(PL_strtab)[hindex];
2522 HE *const next = *head;
2524 /* We don't actually store a HE from the arena and a regular HEK.
2525 Instead we allocate one chunk of memory big enough for both,
2526 and put the HEK straight after the HE. This way we can find the
2527 HEK directly from the HE.
2530 Newx(k, STRUCT_OFFSET(struct shared_he,
2531 shared_he_hek.hek_key[0]) + len + 2, char);
2532 new_entry = (struct shared_he *)k;
2533 entry = &(new_entry->shared_he_he);
2534 hek = &(new_entry->shared_he_hek);
2536 Copy(str, HEK_KEY(hek), len, char);
2537 HEK_KEY(hek)[len] = 0;
2539 HEK_HASH(hek) = hash;
2540 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2542 /* Still "point" to the HEK, so that other code need not know what
2544 HeKEY_hek(entry) = hek;
2545 entry->he_valu.hent_refcount = 0;
2546 HeNEXT(entry) = next;
2549 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2550 if (!next) { /* initial entry? */
2551 xhv->xhv_fill++; /* HvFILL(hv)++ */
2552 } else if (xhv->xhv_keys > (IV)xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2557 ++entry->he_valu.hent_refcount;
2559 if (flags & HVhek_FREEKEY)
2562 return HeKEY_hek(entry);
2566 Perl_hv_placeholders_p(pTHX_ HV *hv)
2569 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2571 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2574 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2577 Perl_die(aTHX_ "panic: hv_placeholders_p");
2580 return &(mg->mg_len);
2585 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2588 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2590 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2592 return mg ? mg->mg_len : 0;
2596 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2599 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2601 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2606 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2607 Perl_die(aTHX_ "panic: hv_placeholders_set");
2609 /* else we don't need to add magic to record 0 placeholders. */
2613 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2618 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2620 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2625 value = &PL_sv_placeholder;
2628 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2631 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2634 case HVrhek_PV_UTF8:
2635 /* Create a string SV that directly points to the bytes in our
2637 value = newSV_type(SVt_PV);
2638 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2639 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2640 /* This stops anything trying to free it */
2641 SvLEN_set(value, 0);
2643 SvREADONLY_on(value);
2644 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2648 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2649 he->refcounted_he_data[0]);
2655 =for apidoc refcounted_he_chain_2hv
2657 Generates and returns a C<HV *> by walking up the tree starting at the passed
2658 in C<struct refcounted_he *>.
2663 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2667 U32 placeholders = 0;
2668 /* We could chase the chain once to get an idea of the number of keys,
2669 and call ksplit. But for now we'll make a potentially inefficient
2670 hash with only 8 entries in its array. */
2671 const U32 max = HvMAX(hv);
2675 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2676 HvARRAY(hv) = (HE**)array;
2681 U32 hash = chain->refcounted_he_hash;
2683 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2685 HE **oentry = &((HvARRAY(hv))[hash & max]);
2686 HE *entry = *oentry;
2689 for (; entry; entry = HeNEXT(entry)) {
2690 if (HeHASH(entry) == hash) {
2691 /* We might have a duplicate key here. If so, entry is older
2692 than the key we've already put in the hash, so if they are
2693 the same, skip adding entry. */
2695 const STRLEN klen = HeKLEN(entry);
2696 const char *const key = HeKEY(entry);
2697 if (klen == chain->refcounted_he_keylen
2698 && (!!HeKUTF8(entry)
2699 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2700 && memEQ(key, REF_HE_KEY(chain), klen))
2703 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2705 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2706 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2707 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2718 = share_hek_flags(REF_HE_KEY(chain),
2719 chain->refcounted_he_keylen,
2720 chain->refcounted_he_hash,
2721 (chain->refcounted_he_data[0]
2722 & (HVhek_UTF8|HVhek_WASUTF8)));
2724 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2726 value = refcounted_he_value(chain);
2727 if (value == &PL_sv_placeholder)
2729 HeVAL(entry) = value;
2731 /* Link it into the chain. */
2732 HeNEXT(entry) = *oentry;
2733 if (!HeNEXT(entry)) {
2734 /* initial entry. */
2742 chain = chain->refcounted_he_next;
2746 clear_placeholders(hv, placeholders);
2747 HvTOTALKEYS(hv) -= placeholders;
2750 /* We could check in the loop to see if we encounter any keys with key
2751 flags, but it's probably not worth it, as this per-hash flag is only
2752 really meant as an optimisation for things like Storable. */
2754 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2760 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2761 const char *key, STRLEN klen, int flags, U32 hash)
2764 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2765 of your key has to exactly match that which is stored. */
2766 SV *value = &PL_sv_placeholder;
2769 /* No point in doing any of this if there's nothing to find. */
2773 if (flags & HVhek_FREEKEY)
2775 key = SvPV_const(keysv, klen);
2777 is_utf8 = (SvUTF8(keysv) != 0);
2779 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2783 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2784 hash = SvSHARED_HASH(keysv);
2786 PERL_HASH(hash, key, klen);
2790 for (; chain; chain = chain->refcounted_he_next) {
2792 if (hash != chain->refcounted_he_hash)
2794 if (klen != chain->refcounted_he_keylen)
2796 if (memNE(REF_HE_KEY(chain),key,klen))
2798 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2801 if (hash != HEK_HASH(chain->refcounted_he_hek))
2803 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2805 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2807 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2811 value = sv_2mortal(refcounted_he_value(chain));
2816 if (flags & HVhek_FREEKEY)
2823 =for apidoc refcounted_he_new
2825 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2826 stored in a compact form, all references remain the property of the caller.
2827 The C<struct refcounted_he> is returned with a reference count of 1.
2832 struct refcounted_he *
2833 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2834 SV *const key, SV *const value) {
2837 const char *key_p = SvPV_const(key, key_len);
2838 STRLEN value_len = 0;
2839 const char *value_p = NULL;
2842 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2845 value_type = HVrhek_PV;
2846 } else if (SvIOK(value)) {
2847 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2848 } else if (value == &PL_sv_placeholder) {
2849 value_type = HVrhek_delete;
2850 } else if (!SvOK(value)) {
2851 value_type = HVrhek_undef;
2853 value_type = HVrhek_PV;
2856 if (value_type == HVrhek_PV) {
2857 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2858 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2859 value_p = SvPV_const(value, value_len);
2861 value_type = HVrhek_PV_UTF8;
2866 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2867 As we're going to be building hash keys from this value in future,
2868 normalise it now. */
2869 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2870 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2873 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2874 ((value_type == HVrhek_PV
2875 || value_type == HVrhek_PV_UTF8) ?
2876 (void *)value_p : (void *)value),
2880 static struct refcounted_he *
2881 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2882 const char *const key_p, const STRLEN key_len,
2883 const char flags, char value_type,
2884 const void *value, const STRLEN value_len) {
2886 struct refcounted_he *he;
2888 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2889 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2891 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2894 he = (struct refcounted_he*)
2895 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2899 he = (struct refcounted_he*)
2900 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2904 he->refcounted_he_next = parent;
2907 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2908 he->refcounted_he_val.refcounted_he_u_len = value_len;
2909 } else if (value_type == HVrhek_IV) {
2910 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2911 } else if (value_type == HVrhek_UV) {
2912 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2915 PERL_HASH(hash, key_p, key_len);
2918 he->refcounted_he_hash = hash;
2919 he->refcounted_he_keylen = key_len;
2920 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2922 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2925 if (flags & HVhek_WASUTF8) {
2926 /* If it was downgraded from UTF-8, then the pointer returned from
2927 bytes_from_utf8 is an allocated pointer that we must free. */
2931 he->refcounted_he_data[0] = flags;
2932 he->refcounted_he_refcnt = 1;
2938 =for apidoc refcounted_he_free
2940 Decrements the reference count of the passed in C<struct refcounted_he *>
2941 by one. If the reference count reaches zero the structure's memory is freed,
2942 and C<refcounted_he_free> iterates onto the parent node.
2948 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2950 PERL_UNUSED_CONTEXT;
2953 struct refcounted_he *copy;
2957 new_count = --he->refcounted_he_refcnt;
2958 HINTS_REFCNT_UNLOCK;
2964 #ifndef USE_ITHREADS
2965 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2968 he = he->refcounted_he_next;
2969 PerlMemShared_free(copy);
2974 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2979 if (chain->refcounted_he_keylen != 1)
2981 if (*REF_HE_KEY(chain) != ':')
2984 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2986 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2989 /* Stop anyone trying to really mess us up by adding their own value for
2991 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
2992 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
2996 *len = chain->refcounted_he_val.refcounted_he_u_len;
2998 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
2999 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3001 return chain->refcounted_he_data + 1;
3004 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
3005 that interface. Once it works out how to pass in length and UTF-8 ness, this
3006 function will need superseding. */
3007 struct refcounted_he *
3008 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
3010 PERL_ARGS_ASSERT_STORE_COP_LABEL;
3012 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
3013 label, strlen(label));
3017 =for apidoc hv_assert
3019 Check that a hash is in an internally consistent state.
3027 Perl_hv_assert(pTHX_ HV *hv)
3032 int placeholders = 0;
3035 const I32 riter = HvRITER_get(hv);
3036 HE *eiter = HvEITER_get(hv);
3038 PERL_ARGS_ASSERT_HV_ASSERT;
3040 (void)hv_iterinit(hv);
3042 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3043 /* sanity check the values */
3044 if (HeVAL(entry) == &PL_sv_placeholder)
3048 /* sanity check the keys */
3049 if (HeSVKEY(entry)) {
3050 NOOP; /* Don't know what to check on SV keys. */
3051 } else if (HeKUTF8(entry)) {
3053 if (HeKWASUTF8(entry)) {
3054 PerlIO_printf(Perl_debug_log,
3055 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3056 (int) HeKLEN(entry), HeKEY(entry));
3059 } else if (HeKWASUTF8(entry))
3062 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3063 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3064 const int nhashkeys = HvUSEDKEYS(hv);
3065 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3067 if (nhashkeys != real) {
3068 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3071 if (nhashplaceholders != placeholders) {
3072 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3076 if (withflags && ! HvHASKFLAGS(hv)) {
3077 PerlIO_printf(Perl_debug_log,
3078 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3083 sv_dump(MUTABLE_SV(hv));
3085 HvRITER_set(hv, riter); /* Restore hash iterator state */
3086 HvEITER_set(hv, eiter);
3093 * c-indentation-style: bsd
3095 * indent-tabs-mode: t
3098 * ex: set ts=8 sts=4 sw=4 noet: