3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
22 A HV structure represents a Perl hash. It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures. The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value. Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
35 #define PERL_HASH_INTERNAL_ACCESS
38 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
47 /* We could generate this at compile time via (another) auxiliary C
49 const size_t arena_size = Perl_malloc_good_size(PERL_ARENA_SIZE);
50 HE* he = (HE*) Perl_get_arena(aTHX_ arena_size, HE_SVSLOT);
51 HE * const heend = &he[arena_size / sizeof(HE) - 1];
53 PL_body_roots[HE_SVSLOT] = he;
55 HeNEXT(he) = (HE*)(he + 1);
63 #define new_HE() (HE*)safemalloc(sizeof(HE))
64 #define del_HE(p) safefree((char*)p)
73 void ** const root = &PL_body_roots[HE_SVSLOT];
83 #define new_HE() new_he()
86 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
87 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
103 Newx(k, HEK_BASESIZE + len + 2, char);
105 Copy(str, HEK_KEY(hek), len, char);
106 HEK_KEY(hek)[len] = 0;
108 HEK_HASH(hek) = hash;
109 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
111 if (flags & HVhek_FREEKEY)
116 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
120 Perl_free_tied_hv_pool(pTHX)
123 HE *he = PL_hv_fetch_ent_mh;
126 Safefree(HeKEY_hek(he));
130 PL_hv_fetch_ent_mh = NULL;
133 #if defined(USE_ITHREADS)
135 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
139 PERL_ARGS_ASSERT_HEK_DUP;
140 PERL_UNUSED_ARG(param);
145 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
147 /* We already shared this hash key. */
148 (void)share_hek_hek(shared);
152 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
153 HEK_HASH(source), HEK_FLAGS(source));
154 ptr_table_store(PL_ptr_table, source, shared);
160 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
164 PERL_ARGS_ASSERT_HE_DUP;
168 /* look for it in the table first */
169 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
173 /* create anew and remember what it is */
175 ptr_table_store(PL_ptr_table, e, ret);
177 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
178 if (HeKLEN(e) == HEf_SVKEY) {
180 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
181 HeKEY_hek(ret) = (HEK*)k;
182 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
185 /* This is hek_dup inlined, which seems to be important for speed
187 HEK * const source = HeKEY_hek(e);
188 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
191 /* We already shared this hash key. */
192 (void)share_hek_hek(shared);
196 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
197 HEK_HASH(source), HEK_FLAGS(source));
198 ptr_table_store(PL_ptr_table, source, shared);
200 HeKEY_hek(ret) = shared;
203 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
205 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
208 #endif /* USE_ITHREADS */
211 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
214 SV * const sv = sv_newmortal();
216 PERL_ARGS_ASSERT_HV_NOTALLOWED;
218 if (!(flags & HVhek_FREEKEY)) {
219 sv_setpvn(sv, key, klen);
222 /* Need to free saved eventually assign to mortal SV */
223 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
224 sv_usepvn(sv, (char *) key, klen);
226 if (flags & HVhek_UTF8) {
229 Perl_croak(aTHX_ msg, SVfARG(sv));
232 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
238 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
239 the length of the key. The C<hash> parameter is the precomputed hash
240 value; if it is zero then Perl will compute it. The return value will be
241 NULL if the operation failed or if the value did not need to be actually
242 stored within the hash (as in the case of tied hashes). Otherwise it can
243 be dereferenced to get the original C<SV*>. Note that the caller is
244 responsible for suitably incrementing the reference count of C<val> before
245 the call, and decrementing it if the function returned NULL. Effectively
246 a successful hv_store takes ownership of one reference to C<val>. This is
247 usually what you want; a newly created SV has a reference count of one, so
248 if all your code does is create SVs then store them in a hash, hv_store
249 will own the only reference to the new SV, and your code doesn't need to do
250 anything further to tidy up. hv_store is not implemented as a call to
251 hv_store_ent, and does not create a temporary SV for the key, so if your
252 key data is not already in SV form then use hv_store in preference to
255 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
256 information on how to use this function on tied hashes.
258 =for apidoc hv_store_ent
260 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
261 parameter is the precomputed hash value; if it is zero then Perl will
262 compute it. The return value is the new hash entry so created. It will be
263 NULL if the operation failed or if the value did not need to be actually
264 stored within the hash (as in the case of tied hashes). Otherwise the
265 contents of the return value can be accessed using the C<He?> macros
266 described here. Note that the caller is responsible for suitably
267 incrementing the reference count of C<val> before the call, and
268 decrementing it if the function returned NULL. Effectively a successful
269 hv_store_ent takes ownership of one reference to C<val>. This is
270 usually what you want; a newly created SV has a reference count of one, so
271 if all your code does is create SVs then store them in a hash, hv_store
272 will own the only reference to the new SV, and your code doesn't need to do
273 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
274 unlike C<val> it does not take ownership of it, so maintaining the correct
275 reference count on C<key> is entirely the caller's responsibility. hv_store
276 is not implemented as a call to hv_store_ent, and does not create a temporary
277 SV for the key, so if your key data is not already in SV form then use
278 hv_store in preference to hv_store_ent.
280 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
281 information on how to use this function on tied hashes.
283 =for apidoc hv_exists
285 Returns a boolean indicating whether the specified hash key exists. The
286 C<klen> is the length of the key.
290 Returns the SV which corresponds to the specified key in the hash. The
291 C<klen> is the length of the key. If C<lval> is set then the fetch will be
292 part of a store. Check that the return value is non-null before
293 dereferencing it to an C<SV*>.
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
298 =for apidoc hv_exists_ent
300 Returns a boolean indicating whether the specified hash key exists. C<hash>
301 can be a valid precomputed hash value, or 0 to ask for it to be
307 /* returns an HE * structure with the all fields set */
308 /* note that hent_val will be a mortal sv for MAGICAL hashes */
310 =for apidoc hv_fetch_ent
312 Returns the hash entry which corresponds to the specified key in the hash.
313 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
314 if you want the function to compute it. IF C<lval> is set then the fetch
315 will be part of a store. Make sure the return value is non-null before
316 accessing it. The return value when C<tb> is a tied hash is a pointer to a
317 static location, so be sure to make a copy of the structure if you need to
320 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
321 information on how to use this function on tied hashes.
326 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
328 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
329 const int action, SV *val, const U32 hash)
334 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
343 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
347 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
348 int flags, int action, SV *val, register U32 hash)
357 const int return_svp = action & HV_FETCH_JUST_SV;
361 if (SvTYPE(hv) == SVTYPEMASK)
364 assert(SvTYPE(hv) == SVt_PVHV);
366 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
368 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
369 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
370 if (uf->uf_set == NULL) {
371 SV* obj = mg->mg_obj;
374 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
375 ((flags & HVhek_UTF8)
379 mg->mg_obj = keysv; /* pass key */
380 uf->uf_index = action; /* pass action */
381 magic_getuvar(MUTABLE_SV(hv), mg);
382 keysv = mg->mg_obj; /* may have changed */
385 /* If the key may have changed, then we need to invalidate
386 any passed-in computed hash value. */
392 if (flags & HVhek_FREEKEY)
394 key = SvPV_const(keysv, klen);
395 is_utf8 = (SvUTF8(keysv) != 0);
396 if (SvIsCOW_shared_hash(keysv)) {
397 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
402 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
405 if (action & HV_DELETE) {
406 return (void *) hv_delete_common(hv, keysv, key, klen,
407 flags | (is_utf8 ? HVhek_UTF8 : 0),
411 xhv = (XPVHV*)SvANY(hv);
413 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
414 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
415 || SvGMAGICAL((const SV *)hv))
417 /* FIXME should be able to skimp on the HE/HEK here when
418 HV_FETCH_JUST_SV is true. */
420 keysv = newSVpvn_utf8(key, klen, is_utf8);
422 keysv = newSVsv(keysv);
425 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
427 /* grab a fake HE/HEK pair from the pool or make a new one */
428 entry = PL_hv_fetch_ent_mh;
430 PL_hv_fetch_ent_mh = HeNEXT(entry);
434 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
435 HeKEY_hek(entry) = (HEK*)k;
437 HeNEXT(entry) = NULL;
438 HeSVKEY_set(entry, keysv);
440 sv_upgrade(sv, SVt_PVLV);
442 /* so we can free entry when freeing sv */
443 LvTARG(sv) = MUTABLE_SV(entry);
445 /* XXX remove at some point? */
446 if (flags & HVhek_FREEKEY)
450 return entry ? (void *) &HeVAL(entry) : NULL;
452 return (void *) entry;
454 #ifdef ENV_IS_CASELESS
455 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
457 for (i = 0; i < klen; ++i)
458 if (isLOWER(key[i])) {
459 /* Would be nice if we had a routine to do the
460 copy and upercase in a single pass through. */
461 const char * const nkey = strupr(savepvn(key,klen));
462 /* Note that this fetch is for nkey (the uppercased
463 key) whereas the store is for key (the original) */
464 void *result = hv_common(hv, NULL, nkey, klen,
465 HVhek_FREEKEY, /* free nkey */
466 0 /* non-LVAL fetch */
467 | HV_DISABLE_UVAR_XKEY
470 0 /* compute hash */);
471 if (!result && (action & HV_FETCH_LVALUE)) {
472 /* This call will free key if necessary.
473 Do it this way to encourage compiler to tail
475 result = hv_common(hv, keysv, key, klen, flags,
477 | HV_DISABLE_UVAR_XKEY
481 if (flags & HVhek_FREEKEY)
489 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
490 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
491 || SvGMAGICAL((const SV *)hv)) {
492 /* I don't understand why hv_exists_ent has svret and sv,
493 whereas hv_exists only had one. */
494 SV * const svret = sv_newmortal();
497 if (keysv || is_utf8) {
499 keysv = newSVpvn_utf8(key, klen, TRUE);
501 keysv = newSVsv(keysv);
503 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
505 mg_copy(MUTABLE_SV(hv), sv, key, klen);
507 if (flags & HVhek_FREEKEY)
509 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
510 /* This cast somewhat evil, but I'm merely using NULL/
511 not NULL to return the boolean exists.
512 And I know hv is not NULL. */
513 return SvTRUE(svret) ? (void *)hv : NULL;
515 #ifdef ENV_IS_CASELESS
516 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
517 /* XXX This code isn't UTF8 clean. */
518 char * const keysave = (char * const)key;
519 /* Will need to free this, so set FREEKEY flag. */
520 key = savepvn(key,klen);
521 key = (const char*)strupr((char*)key);
526 if (flags & HVhek_FREEKEY) {
529 flags |= HVhek_FREEKEY;
533 else if (action & HV_FETCH_ISSTORE) {
536 hv_magic_check (hv, &needs_copy, &needs_store);
538 const bool save_taint = PL_tainted;
539 if (keysv || is_utf8) {
541 keysv = newSVpvn_utf8(key, klen, TRUE);
544 PL_tainted = SvTAINTED(keysv);
545 keysv = sv_2mortal(newSVsv(keysv));
546 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
548 mg_copy(MUTABLE_SV(hv), val, key, klen);
551 TAINT_IF(save_taint);
553 if (flags & HVhek_FREEKEY)
557 #ifdef ENV_IS_CASELESS
558 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
559 /* XXX This code isn't UTF8 clean. */
560 const char *keysave = key;
561 /* Will need to free this, so set FREEKEY flag. */
562 key = savepvn(key,klen);
563 key = (const char*)strupr((char*)key);
568 if (flags & HVhek_FREEKEY) {
571 flags |= HVhek_FREEKEY;
579 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
580 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
581 || (SvRMAGICAL((const SV *)hv)
582 && mg_find((const SV *)hv, PERL_MAGIC_env))
587 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
589 HvARRAY(hv) = (HE**)array;
591 #ifdef DYNAMIC_ENV_FETCH
592 else if (action & HV_FETCH_ISEXISTS) {
593 /* for an %ENV exists, if we do an insert it's by a recursive
594 store call, so avoid creating HvARRAY(hv) right now. */
598 /* XXX remove at some point? */
599 if (flags & HVhek_FREEKEY)
606 if (is_utf8 & !(flags & HVhek_KEYCANONICAL)) {
607 char * const keysave = (char *)key;
608 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
612 flags &= ~HVhek_UTF8;
613 if (key != keysave) {
614 if (flags & HVhek_FREEKEY)
616 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
617 /* If the caller calculated a hash, it was on the sequence of
618 octets that are the UTF-8 form. We've now changed the sequence
619 of octets stored to that of the equivalent byte representation,
620 so the hash we need is different. */
626 PERL_HASH_INTERNAL(hash, key, klen);
627 /* We don't have a pointer to the hv, so we have to replicate the
628 flag into every HEK, so that hv_iterkeysv can see it. */
629 /* And yes, you do need this even though you are not "storing" because
630 you can flip the flags below if doing an lval lookup. (And that
631 was put in to give the semantics Andreas was expecting.) */
632 flags |= HVhek_REHASH;
634 if (keysv && (SvIsCOW_shared_hash(keysv))) {
635 hash = SvSHARED_HASH(keysv);
637 PERL_HASH(hash, key, klen);
641 masked_flags = (flags & HVhek_MASK);
643 #ifdef DYNAMIC_ENV_FETCH
644 if (!HvARRAY(hv)) entry = NULL;
648 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
650 for (; entry; entry = HeNEXT(entry)) {
651 if (HeHASH(entry) != hash) /* strings can't be equal */
653 if (HeKLEN(entry) != (I32)klen)
655 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
657 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
660 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
661 if (HeKFLAGS(entry) != masked_flags) {
662 /* We match if HVhek_UTF8 bit in our flags and hash key's
663 match. But if entry was set previously with HVhek_WASUTF8
664 and key now doesn't (or vice versa) then we should change
665 the key's flag, as this is assignment. */
666 if (HvSHAREKEYS(hv)) {
667 /* Need to swap the key we have for a key with the flags we
668 need. As keys are shared we can't just write to the
669 flag, so we share the new one, unshare the old one. */
670 HEK * const new_hek = share_hek_flags(key, klen, hash,
672 unshare_hek (HeKEY_hek(entry));
673 HeKEY_hek(entry) = new_hek;
675 else if (hv == PL_strtab) {
676 /* PL_strtab is usually the only hash without HvSHAREKEYS,
677 so putting this test here is cheap */
678 if (flags & HVhek_FREEKEY)
680 Perl_croak(aTHX_ S_strtab_error,
681 action & HV_FETCH_LVALUE ? "fetch" : "store");
684 HeKFLAGS(entry) = masked_flags;
685 if (masked_flags & HVhek_ENABLEHVKFLAGS)
688 if (HeVAL(entry) == &PL_sv_placeholder) {
689 /* yes, can store into placeholder slot */
690 if (action & HV_FETCH_LVALUE) {
692 /* This preserves behaviour with the old hv_fetch
693 implementation which at this point would bail out
694 with a break; (at "if we find a placeholder, we
695 pretend we haven't found anything")
697 That break mean that if a placeholder were found, it
698 caused a call into hv_store, which in turn would
699 check magic, and if there is no magic end up pretty
700 much back at this point (in hv_store's code). */
703 /* LVAL fetch which actaully needs a store. */
705 HvPLACEHOLDERS(hv)--;
708 if (val != &PL_sv_placeholder)
709 HvPLACEHOLDERS(hv)--;
712 } else if (action & HV_FETCH_ISSTORE) {
713 SvREFCNT_dec(HeVAL(entry));
716 } else if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* if we find a placeholder, we pretend we haven't found
721 if (flags & HVhek_FREEKEY)
724 return entry ? (void *) &HeVAL(entry) : NULL;
728 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
729 if (!(action & HV_FETCH_ISSTORE)
730 && SvRMAGICAL((const SV *)hv)
731 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
733 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
735 sv = newSVpvn(env,len);
737 return hv_common(hv, keysv, key, klen, flags,
738 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
744 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
745 hv_notallowed(flags, key, klen,
746 "Attempt to access disallowed key '%"SVf"' in"
747 " a restricted hash");
749 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
750 /* Not doing some form of store, so return failure. */
751 if (flags & HVhek_FREEKEY)
755 if (action & HV_FETCH_LVALUE) {
758 /* At this point the old hv_fetch code would call to hv_store,
759 which in turn might do some tied magic. So we need to make that
760 magic check happen. */
761 /* gonna assign to this, so it better be there */
762 /* If a fetch-as-store fails on the fetch, then the action is to
763 recurse once into "hv_store". If we didn't do this, then that
764 recursive call would call the key conversion routine again.
765 However, as we replace the original key with the converted
766 key, this would result in a double conversion, which would show
767 up as a bug if the conversion routine is not idempotent. */
768 return hv_common(hv, keysv, key, klen, flags,
769 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
771 /* XXX Surely that could leak if the fetch-was-store fails?
772 Just like the hv_fetch. */
776 /* Welcome to hv_store... */
779 /* Not sure if we can get here. I think the only case of oentry being
780 NULL is for %ENV with dynamic env fetch. But that should disappear
781 with magic in the previous code. */
784 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
786 HvARRAY(hv) = (HE**)array;
789 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
792 /* share_hek_flags will do the free for us. This might be considered
795 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
796 else if (hv == PL_strtab) {
797 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
798 this test here is cheap */
799 if (flags & HVhek_FREEKEY)
801 Perl_croak(aTHX_ S_strtab_error,
802 action & HV_FETCH_LVALUE ? "fetch" : "store");
804 else /* gotta do the real thing */
805 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
807 HeNEXT(entry) = *oentry;
810 if (val == &PL_sv_placeholder)
811 HvPLACEHOLDERS(hv)++;
812 if (masked_flags & HVhek_ENABLEHVKFLAGS)
816 const HE *counter = HeNEXT(entry);
818 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
819 if (!counter) { /* initial entry? */
820 } else if (xhv->xhv_keys > xhv->xhv_max) {
822 } else if(!HvREHASH(hv)) {
825 while ((counter = HeNEXT(counter)))
828 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
829 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
830 bucket splits on a rehashed hash, as we're not going to
831 split it again, and if someone is lucky (evil) enough to
832 get all the keys in one list they could exhaust our memory
833 as we repeatedly double the number of buckets on every
834 entry. Linear search feels a less worse thing to do. */
841 return entry ? (void *) &HeVAL(entry) : NULL;
843 return (void *) entry;
847 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
849 const MAGIC *mg = SvMAGIC(hv);
851 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
856 if (isUPPER(mg->mg_type)) {
858 if (mg->mg_type == PERL_MAGIC_tied) {
859 *needs_store = FALSE;
860 return; /* We've set all there is to set. */
863 mg = mg->mg_moremagic;
868 =for apidoc hv_scalar
870 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
876 Perl_hv_scalar(pTHX_ HV *hv)
880 PERL_ARGS_ASSERT_HV_SCALAR;
882 if (SvRMAGICAL(hv)) {
883 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
885 return magic_scalarpack(hv, mg);
889 if (HvTOTALKEYS((const HV *)hv))
890 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
891 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
899 =for apidoc hv_delete
901 Deletes a key/value pair in the hash. The value SV is removed from the
902 hash and returned to the caller. The C<klen> is the length of the key.
903 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
906 =for apidoc hv_delete_ent
908 Deletes a key/value pair in the hash. The value SV is removed from the
909 hash and returned to the caller. The C<flags> value will normally be zero;
910 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
911 precomputed hash value, or 0 to ask for it to be computed.
917 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
918 int k_flags, I32 d_flags, U32 hash)
923 register HE **oentry;
924 HE *const *first_entry;
925 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
928 if (SvRMAGICAL(hv)) {
931 hv_magic_check (hv, &needs_copy, &needs_store);
935 entry = (HE *) hv_common(hv, keysv, key, klen,
936 k_flags & ~HVhek_FREEKEY,
937 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
939 sv = entry ? HeVAL(entry) : NULL;
945 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
946 /* No longer an element */
947 sv_unmagic(sv, PERL_MAGIC_tiedelem);
950 return NULL; /* element cannot be deleted */
952 #ifdef ENV_IS_CASELESS
953 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
954 /* XXX This code isn't UTF8 clean. */
955 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
956 if (k_flags & HVhek_FREEKEY) {
959 key = strupr(SvPVX(keysv));
968 xhv = (XPVHV*)SvANY(hv);
973 const char * const keysave = key;
974 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
977 k_flags |= HVhek_UTF8;
979 k_flags &= ~HVhek_UTF8;
980 if (key != keysave) {
981 if (k_flags & HVhek_FREEKEY) {
982 /* This shouldn't happen if our caller does what we expect,
983 but strictly the API allows it. */
986 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
988 HvHASKFLAGS_on(MUTABLE_SV(hv));
992 PERL_HASH_INTERNAL(hash, key, klen);
994 if (keysv && (SvIsCOW_shared_hash(keysv))) {
995 hash = SvSHARED_HASH(keysv);
997 PERL_HASH(hash, key, klen);
1001 masked_flags = (k_flags & HVhek_MASK);
1003 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1005 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1007 if (HeHASH(entry) != hash) /* strings can't be equal */
1009 if (HeKLEN(entry) != (I32)klen)
1011 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1013 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1016 if (hv == PL_strtab) {
1017 if (k_flags & HVhek_FREEKEY)
1019 Perl_croak(aTHX_ S_strtab_error, "delete");
1022 /* if placeholder is here, it's already been deleted.... */
1023 if (HeVAL(entry) == &PL_sv_placeholder) {
1024 if (k_flags & HVhek_FREEKEY)
1028 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1029 hv_notallowed(k_flags, key, klen,
1030 "Attempt to delete readonly key '%"SVf"' from"
1031 " a restricted hash");
1033 if (k_flags & HVhek_FREEKEY)
1036 if (d_flags & G_DISCARD)
1039 sv = sv_2mortal(HeVAL(entry));
1040 HeVAL(entry) = &PL_sv_placeholder;
1044 * If a restricted hash, rather than really deleting the entry, put
1045 * a placeholder there. This marks the key as being "approved", so
1046 * we can still access via not-really-existing key without raising
1049 if (SvREADONLY(hv)) {
1050 SvREFCNT_dec(HeVAL(entry));
1051 HeVAL(entry) = &PL_sv_placeholder;
1052 /* We'll be saving this slot, so the number of allocated keys
1053 * doesn't go down, but the number placeholders goes up */
1054 HvPLACEHOLDERS(hv)++;
1056 *oentry = HeNEXT(entry);
1057 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1060 hv_free_ent(hv, entry);
1061 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1062 if (xhv->xhv_keys == 0)
1063 HvHASKFLAGS_off(hv);
1067 if (SvREADONLY(hv)) {
1068 hv_notallowed(k_flags, key, klen,
1069 "Attempt to delete disallowed key '%"SVf"' from"
1070 " a restricted hash");
1073 if (k_flags & HVhek_FREEKEY)
1079 S_hsplit(pTHX_ HV *hv)
1082 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1083 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1084 register I32 newsize = oldsize * 2;
1086 char *a = (char*) HvARRAY(hv);
1088 register HE **oentry;
1089 int longest_chain = 0;
1092 PERL_ARGS_ASSERT_HSPLIT;
1094 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1095 (void*)hv, (int) oldsize);*/
1097 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1098 /* Can make this clear any placeholders first for non-restricted hashes,
1099 even though Storable rebuilds restricted hashes by putting in all the
1100 placeholders (first) before turning on the readonly flag, because
1101 Storable always pre-splits the hash. */
1102 hv_clear_placeholders(hv);
1106 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1107 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1108 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1114 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1117 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1118 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1123 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1125 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1127 if (oldsize >= 64) {
1128 offer_nice_chunk(HvARRAY(hv),
1129 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1130 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1133 Safefree(HvARRAY(hv));
1137 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1138 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1139 HvARRAY(hv) = (HE**) a;
1142 for (i=0; i<oldsize; i++,aep++) {
1143 int left_length = 0;
1144 int right_length = 0;
1148 if (!*aep) /* non-existent */
1151 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1152 if ((HeHASH(entry) & newsize) != (U32)i) {
1153 *oentry = HeNEXT(entry);
1154 HeNEXT(entry) = *bep;
1160 oentry = &HeNEXT(entry);
1164 /* I think we don't actually need to keep track of the longest length,
1165 merely flag if anything is too long. But for the moment while
1166 developing this code I'll track it. */
1167 if (left_length > longest_chain)
1168 longest_chain = left_length;
1169 if (right_length > longest_chain)
1170 longest_chain = right_length;
1174 /* Pick your policy for "hashing isn't working" here: */
1175 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1180 if (hv == PL_strtab) {
1181 /* Urg. Someone is doing something nasty to the string table.
1186 /* Awooga. Awooga. Pathological data. */
1187 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1188 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1191 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1192 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1194 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1197 was_shared = HvSHAREKEYS(hv);
1199 HvSHAREKEYS_off(hv);
1204 for (i=0; i<newsize; i++,aep++) {
1205 register HE *entry = *aep;
1207 /* We're going to trash this HE's next pointer when we chain it
1208 into the new hash below, so store where we go next. */
1209 HE * const next = HeNEXT(entry);
1214 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1219 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1220 hash, HeKFLAGS(entry));
1221 unshare_hek (HeKEY_hek(entry));
1222 HeKEY_hek(entry) = new_hek;
1224 /* Not shared, so simply write the new hash in. */
1225 HeHASH(entry) = hash;
1227 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1228 HEK_REHASH_on(HeKEY_hek(entry));
1229 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1231 /* Copy oentry to the correct new chain. */
1232 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1233 HeNEXT(entry) = *bep;
1239 Safefree (HvARRAY(hv));
1240 HvARRAY(hv) = (HE **)a;
1244 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1247 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1248 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1249 register I32 newsize;
1254 register HE **oentry;
1256 PERL_ARGS_ASSERT_HV_KSPLIT;
1258 newsize = (I32) newmax; /* possible truncation here */
1259 if (newsize != newmax || newmax <= oldsize)
1261 while ((newsize & (1 + ~newsize)) != newsize) {
1262 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1264 if (newsize < newmax)
1266 if (newsize < newmax)
1267 return; /* overflow detection */
1269 a = (char *) HvARRAY(hv);
1272 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1273 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1274 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1280 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1283 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1284 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1289 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1291 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1293 if (oldsize >= 64) {
1294 offer_nice_chunk(HvARRAY(hv),
1295 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1296 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1299 Safefree(HvARRAY(hv));
1302 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1305 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1307 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1308 HvARRAY(hv) = (HE **) a;
1309 if (!xhv->xhv_keys /* !HvTOTALKEYS(hv) */) /* skip rest if no entries */
1313 for (i=0; i<oldsize; i++,aep++) {
1314 if (!*aep) /* non-existent */
1316 for (oentry = aep, entry = *aep; entry; entry = *oentry) {
1317 register I32 j = (HeHASH(entry) & newsize);
1321 *oentry = HeNEXT(entry);
1322 HeNEXT(entry) = aep[j];
1327 oentry = &HeNEXT(entry);
1333 Perl_newHVhv(pTHX_ HV *ohv)
1336 HV * const hv = newHV();
1339 if (!ohv || !HvTOTALKEYS(ohv))
1341 hv_max = HvMAX(ohv);
1343 if (!SvMAGICAL((const SV *)ohv)) {
1344 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1346 const bool shared = !!HvSHAREKEYS(ohv);
1347 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1349 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1352 /* In each bucket... */
1353 for (i = 0; i <= hv_max; i++) {
1355 HE *oent = oents[i];
1362 /* Copy the linked list of entries. */
1363 for (; oent; oent = HeNEXT(oent)) {
1364 const U32 hash = HeHASH(oent);
1365 const char * const key = HeKEY(oent);
1366 const STRLEN len = HeKLEN(oent);
1367 const int flags = HeKFLAGS(oent);
1368 HE * const ent = new_HE();
1369 SV *const val = HeVAL(oent);
1371 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1373 = shared ? share_hek_flags(key, len, hash, flags)
1374 : save_hek_flags(key, len, hash, flags);
1385 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1389 /* Iterate over ohv, copying keys and values one at a time. */
1391 const I32 riter = HvRITER_get(ohv);
1392 HE * const eiter = HvEITER_get(ohv);
1393 STRLEN hv_fill = HvFILL(ohv);
1395 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1396 while (hv_max && hv_max + 1 >= hv_fill * 2)
1397 hv_max = hv_max / 2;
1401 while ((entry = hv_iternext_flags(ohv, 0))) {
1402 SV *const val = HeVAL(entry);
1403 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1404 SvIMMORTAL(val) ? val : newSVsv(val),
1405 HeHASH(entry), HeKFLAGS(entry));
1407 HvRITER_set(ohv, riter);
1408 HvEITER_set(ohv, eiter);
1414 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1415 magic stays on it. */
1417 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1419 HV * const hv = newHV();
1421 if (ohv && HvTOTALKEYS(ohv)) {
1422 STRLEN hv_max = HvMAX(ohv);
1423 STRLEN hv_fill = HvFILL(ohv);
1425 const I32 riter = HvRITER_get(ohv);
1426 HE * const eiter = HvEITER_get(ohv);
1428 while (hv_max && hv_max + 1 >= hv_fill * 2)
1429 hv_max = hv_max / 2;
1433 while ((entry = hv_iternext_flags(ohv, 0))) {
1434 SV *const sv = newSVsv(HeVAL(entry));
1435 SV *heksv = newSVhek(HeKEY_hek(entry));
1436 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1437 (char *)heksv, HEf_SVKEY);
1438 SvREFCNT_dec(heksv);
1439 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1440 sv, HeHASH(entry), HeKFLAGS(entry));
1442 HvRITER_set(ohv, riter);
1443 HvEITER_set(ohv, eiter);
1445 hv_magic(hv, NULL, PERL_MAGIC_hints);
1450 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1455 PERL_ARGS_ASSERT_HV_FREE_ENT;
1460 if (HvNAME(hv) && anonymise_cv(HvNAME_HEK(hv), val) && GvCVu(val))
1461 mro_method_changed_in(hv);
1463 if (HeKLEN(entry) == HEf_SVKEY) {
1464 SvREFCNT_dec(HeKEY_sv(entry));
1465 Safefree(HeKEY_hek(entry));
1467 else if (HvSHAREKEYS(hv))
1468 unshare_hek(HeKEY_hek(entry));
1470 Safefree(HeKEY_hek(entry));
1475 S_anonymise_cv(pTHX_ HEK *stash, SV *val)
1479 PERL_ARGS_ASSERT_ANONYMISE_CV;
1481 if (val && isGV(val) && isGV_with_GP(val) && (cv = GvCV(val))) {
1482 if ((SV *)CvGV(cv) == val) {
1486 SV *gvname = newSVhek(stash);
1487 sv_catpvs(gvname, "::__ANON__");
1488 anongv = gv_fetchsv(gvname, GV_ADDMULTI, SVt_PVCV);
1489 SvREFCNT_dec(gvname);
1491 anongv = gv_fetchpvs("__ANON__::__ANON__", GV_ADDMULTI,
1503 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1507 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1511 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1512 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1513 if (HeKLEN(entry) == HEf_SVKEY) {
1514 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1516 hv_free_ent(hv, entry);
1520 =for apidoc hv_clear
1522 Clears a hash, making it empty.
1528 Perl_hv_clear(pTHX_ HV *hv)
1531 register XPVHV* xhv;
1535 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1537 xhv = (XPVHV*)SvANY(hv);
1539 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1540 /* restricted hash: convert all keys to placeholders */
1542 for (i = 0; i <= xhv->xhv_max; i++) {
1543 HE *entry = (HvARRAY(hv))[i];
1544 for (; entry; entry = HeNEXT(entry)) {
1545 /* not already placeholder */
1546 if (HeVAL(entry) != &PL_sv_placeholder) {
1547 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1548 SV* const keysv = hv_iterkeysv(entry);
1550 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1553 SvREFCNT_dec(HeVAL(entry));
1554 HeVAL(entry) = &PL_sv_placeholder;
1555 HvPLACEHOLDERS(hv)++;
1563 HvPLACEHOLDERS_set(hv, 0);
1565 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1568 mg_clear(MUTABLE_SV(hv));
1570 HvHASKFLAGS_off(hv);
1575 mro_isa_changed_in(hv);
1576 HvEITER_set(hv, NULL);
1581 =for apidoc hv_clear_placeholders
1583 Clears any placeholders from a hash. If a restricted hash has any of its keys
1584 marked as readonly and the key is subsequently deleted, the key is not actually
1585 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1586 it so it will be ignored by future operations such as iterating over the hash,
1587 but will still allow the hash to have a value reassigned to the key at some
1588 future point. This function clears any such placeholder keys from the hash.
1589 See Hash::Util::lock_keys() for an example of its use.
1595 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1598 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1600 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1603 clear_placeholders(hv, items);
1607 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1612 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1619 /* Loop down the linked list heads */
1621 HE **oentry = &(HvARRAY(hv))[i];
1624 while ((entry = *oentry)) {
1625 if (HeVAL(entry) == &PL_sv_placeholder) {
1626 *oentry = HeNEXT(entry);
1627 if (entry == HvEITER_get(hv))
1630 hv_free_ent(hv, entry);
1634 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1635 if (HvKEYS(hv) == 0)
1636 HvHASKFLAGS_off(hv);
1637 HvPLACEHOLDERS_set(hv, 0);
1641 oentry = &HeNEXT(entry);
1646 /* You can't get here, hence assertion should always fail. */
1647 assert (items == 0);
1652 S_hfreeentries(pTHX_ HV *hv)
1654 /* This is the array that we're going to restore */
1655 HE **const orig_array = HvARRAY(hv);
1659 PERL_ARGS_ASSERT_HFREEENTRIES;
1664 if (HvNAME(hv) && orig_array != NULL) {
1665 /* symbol table: make all the contained subs ANON */
1667 XPVHV *xhv = (XPVHV*)SvANY(hv);
1669 for (i = 0; i <= xhv->xhv_max; i++) {
1670 HE *entry = (HvARRAY(hv))[i];
1671 for (; entry; entry = HeNEXT(entry)) {
1672 SV *val = HeVAL(entry);
1673 /* we need to put the subs in the __ANON__ symtable, as
1674 * this one is being cleared. */
1675 anonymise_cv(NULL, val);
1681 /* If the hash is actually a symbol table with a name, look after the
1683 struct xpvhv_aux *iter = HvAUX(hv);
1685 name = iter->xhv_name;
1686 iter->xhv_name = NULL;
1691 /* orig_array remains unchanged throughout the loop. If after freeing all
1692 the entries it turns out that one of the little blighters has triggered
1693 an action that has caused HvARRAY to be re-allocated, then we set
1694 array to the new HvARRAY, and try again. */
1697 /* This is the one we're going to try to empty. First time round
1698 it's the original array. (Hopefully there will only be 1 time
1700 HE ** const array = HvARRAY(hv);
1703 /* Because we have taken xhv_name out, the only allocated pointer
1704 in the aux structure that might exist is the backreference array.
1709 struct mro_meta *meta;
1710 struct xpvhv_aux *iter = HvAUX(hv);
1711 /* If there are weak references to this HV, we need to avoid
1712 freeing them up here. In particular we need to keep the AV
1713 visible as what we're deleting might well have weak references
1714 back to this HV, so the for loop below may well trigger
1715 the removal of backreferences from this array. */
1717 if (iter->xhv_backreferences) {
1718 /* So donate them to regular backref magic to keep them safe.
1719 The sv_magic will increase the reference count of the AV,
1720 so we need to drop it first. */
1721 SvREFCNT_dec(iter->xhv_backreferences);
1722 if (AvFILLp(iter->xhv_backreferences) == -1) {
1723 /* Turns out that the array is empty. Just free it. */
1724 SvREFCNT_dec(iter->xhv_backreferences);
1727 sv_magic(MUTABLE_SV(hv),
1728 MUTABLE_SV(iter->xhv_backreferences),
1729 PERL_MAGIC_backref, NULL, 0);
1731 iter->xhv_backreferences = NULL;
1734 entry = iter->xhv_eiter; /* HvEITER(hv) */
1735 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1737 hv_free_ent(hv, entry);
1739 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1740 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1742 if((meta = iter->xhv_mro_meta)) {
1743 if (meta->mro_linear_all) {
1744 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1745 meta->mro_linear_all = NULL;
1746 /* This is just acting as a shortcut pointer. */
1747 meta->mro_linear_current = NULL;
1748 } else if (meta->mro_linear_current) {
1749 /* Only the current MRO is stored, so this owns the data.
1751 SvREFCNT_dec(meta->mro_linear_current);
1752 meta->mro_linear_current = NULL;
1754 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1755 SvREFCNT_dec(meta->isa);
1757 iter->xhv_mro_meta = NULL;
1760 /* There are now no allocated pointers in the aux structure. */
1762 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1763 /* What aux structure? */
1766 /* make everyone else think the array is empty, so that the destructors
1767 * called for freed entries can't recusively mess with us */
1769 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1773 /* Loop down the linked list heads */
1774 HE *entry = array[i];
1777 register HE * const oentry = entry;
1778 entry = HeNEXT(entry);
1779 hv_free_ent(hv, oentry);
1783 /* As there are no allocated pointers in the aux structure, it's now
1784 safe to free the array we just cleaned up, if it's not the one we're
1785 going to put back. */
1786 if (array != orig_array) {
1791 /* Good. No-one added anything this time round. */
1796 /* Someone attempted to iterate or set the hash name while we had
1797 the array set to 0. We'll catch backferences on the next time
1798 round the while loop. */
1799 assert(HvARRAY(hv));
1801 if (HvAUX(hv)->xhv_name) {
1802 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1806 if (--attempts == 0) {
1807 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1811 HvARRAY(hv) = orig_array;
1813 /* If the hash was actually a symbol table, put the name back. */
1815 /* We have restored the original array. If name is non-NULL, then
1816 the original array had an aux structure at the end. So this is
1818 SvFLAGS(hv) |= SVf_OOK;
1819 HvAUX(hv)->xhv_name = name;
1824 =for apidoc hv_undef
1832 Perl_hv_undef(pTHX_ HV *hv)
1835 register XPVHV* xhv;
1840 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1841 xhv = (XPVHV*)SvANY(hv);
1843 if ((name = HvNAME_get(hv)) && !PL_dirty)
1844 mro_isa_changed_in(hv);
1849 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1850 hv_name_set(hv, NULL, 0, 0);
1852 SvFLAGS(hv) &= ~SVf_OOK;
1853 Safefree(HvARRAY(hv));
1854 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1856 HvPLACEHOLDERS_set(hv, 0);
1859 mg_clear(MUTABLE_SV(hv));
1865 Returns the number of hash buckets that happen to be in use. This function is
1866 wrapped by the macro C<HvFILL>.
1868 Previously this value was stored in the HV structure, rather than being
1869 calculated on demand.
1875 Perl_hv_fill(pTHX_ HV const *const hv)
1878 HE **ents = HvARRAY(hv);
1880 PERL_ARGS_ASSERT_HV_FILL;
1883 HE *const *const last = ents + HvMAX(hv);
1884 count = last + 1 - ents;
1889 } while (++ents <= last);
1894 static struct xpvhv_aux*
1895 S_hv_auxinit(HV *hv) {
1896 struct xpvhv_aux *iter;
1899 PERL_ARGS_ASSERT_HV_AUXINIT;
1902 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1903 + sizeof(struct xpvhv_aux), char);
1905 array = (char *) HvARRAY(hv);
1906 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1907 + sizeof(struct xpvhv_aux), char);
1909 HvARRAY(hv) = (HE**) array;
1910 /* SvOOK_on(hv) attacks the IV flags. */
1911 SvFLAGS(hv) |= SVf_OOK;
1914 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1915 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1917 iter->xhv_backreferences = 0;
1918 iter->xhv_mro_meta = NULL;
1923 =for apidoc hv_iterinit
1925 Prepares a starting point to traverse a hash table. Returns the number of
1926 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1927 currently only meaningful for hashes without tie magic.
1929 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1930 hash buckets that happen to be in use. If you still need that esoteric
1931 value, you can get it through the macro C<HvFILL(tb)>.
1938 Perl_hv_iterinit(pTHX_ HV *hv)
1940 PERL_ARGS_ASSERT_HV_ITERINIT;
1942 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1945 Perl_croak(aTHX_ "Bad hash");
1948 struct xpvhv_aux * const iter = HvAUX(hv);
1949 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1950 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1952 hv_free_ent(hv, entry);
1954 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1955 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1960 /* used to be xhv->xhv_fill before 5.004_65 */
1961 return HvTOTALKEYS(hv);
1965 Perl_hv_riter_p(pTHX_ HV *hv) {
1966 struct xpvhv_aux *iter;
1968 PERL_ARGS_ASSERT_HV_RITER_P;
1971 Perl_croak(aTHX_ "Bad hash");
1973 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1974 return &(iter->xhv_riter);
1978 Perl_hv_eiter_p(pTHX_ HV *hv) {
1979 struct xpvhv_aux *iter;
1981 PERL_ARGS_ASSERT_HV_EITER_P;
1984 Perl_croak(aTHX_ "Bad hash");
1986 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1987 return &(iter->xhv_eiter);
1991 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1992 struct xpvhv_aux *iter;
1994 PERL_ARGS_ASSERT_HV_RITER_SET;
1997 Perl_croak(aTHX_ "Bad hash");
2005 iter = hv_auxinit(hv);
2007 iter->xhv_riter = riter;
2011 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2012 struct xpvhv_aux *iter;
2014 PERL_ARGS_ASSERT_HV_EITER_SET;
2017 Perl_croak(aTHX_ "Bad hash");
2022 /* 0 is the default so don't go malloc()ing a new structure just to
2027 iter = hv_auxinit(hv);
2029 iter->xhv_eiter = eiter;
2033 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2036 struct xpvhv_aux *iter;
2039 PERL_ARGS_ASSERT_HV_NAME_SET;
2040 PERL_UNUSED_ARG(flags);
2043 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2047 if (iter->xhv_name) {
2048 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2054 iter = hv_auxinit(hv);
2056 PERL_HASH(hash, name, len);
2057 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2061 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2062 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2064 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2065 PERL_UNUSED_CONTEXT;
2067 return &(iter->xhv_backreferences);
2071 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2074 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2079 av = HvAUX(hv)->xhv_backreferences;
2082 HvAUX(hv)->xhv_backreferences = 0;
2083 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2089 hv_iternext is implemented as a macro in hv.h
2091 =for apidoc hv_iternext
2093 Returns entries from a hash iterator. See C<hv_iterinit>.
2095 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2096 iterator currently points to, without losing your place or invalidating your
2097 iterator. Note that in this case the current entry is deleted from the hash
2098 with your iterator holding the last reference to it. Your iterator is flagged
2099 to free the entry on the next call to C<hv_iternext>, so you must not discard
2100 your iterator immediately else the entry will leak - call C<hv_iternext> to
2101 trigger the resource deallocation.
2103 =for apidoc hv_iternext_flags
2105 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2106 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2107 set the placeholders keys (for restricted hashes) will be returned in addition
2108 to normal keys. By default placeholders are automatically skipped over.
2109 Currently a placeholder is implemented with a value that is
2110 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2111 restricted hashes may change, and the implementation currently is
2112 insufficiently abstracted for any change to be tidy.
2118 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2121 register XPVHV* xhv;
2125 struct xpvhv_aux *iter;
2127 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2130 Perl_croak(aTHX_ "Bad hash");
2132 xhv = (XPVHV*)SvANY(hv);
2135 /* Too many things (well, pp_each at least) merrily assume that you can
2136 call iv_iternext without calling hv_iterinit, so we'll have to deal
2142 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2143 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2144 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2145 SV * const key = sv_newmortal();
2147 sv_setsv(key, HeSVKEY_force(entry));
2148 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2154 /* one HE per MAGICAL hash */
2155 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2157 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2159 HeKEY_hek(entry) = hek;
2160 HeKLEN(entry) = HEf_SVKEY;
2162 magic_nextpack(MUTABLE_SV(hv),mg,key);
2164 /* force key to stay around until next time */
2165 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2166 return entry; /* beware, hent_val is not set */
2168 SvREFCNT_dec(HeVAL(entry));
2169 Safefree(HeKEY_hek(entry));
2171 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2175 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2176 if (!entry && SvRMAGICAL((const SV *)hv)
2177 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2180 /* The prime_env_iter() on VMS just loaded up new hash values
2181 * so the iteration count needs to be reset back to the beginning
2185 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2190 /* hv_iterint now ensures this. */
2191 assert (HvARRAY(hv));
2193 /* At start of hash, entry is NULL. */
2196 entry = HeNEXT(entry);
2197 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2199 * Skip past any placeholders -- don't want to include them in
2202 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2203 entry = HeNEXT(entry);
2208 /* Skip the entire loop if the hash is empty. */
2209 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2210 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2212 /* OK. Come to the end of the current list. Grab the next one. */
2214 iter->xhv_riter++; /* HvRITER(hv)++ */
2215 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2216 /* There is no next one. End of the hash. */
2217 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2220 entry = (HvARRAY(hv))[iter->xhv_riter];
2222 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2223 /* If we have an entry, but it's a placeholder, don't count it.
2225 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2226 entry = HeNEXT(entry);
2228 /* Will loop again if this linked list starts NULL
2229 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2230 or if we run through it and find only placeholders. */
2234 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2236 hv_free_ent(hv, oldentry);
2239 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2240 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2242 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2247 =for apidoc hv_iterkey
2249 Returns the key from the current position of the hash iterator. See
2256 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2258 PERL_ARGS_ASSERT_HV_ITERKEY;
2260 if (HeKLEN(entry) == HEf_SVKEY) {
2262 char * const p = SvPV(HeKEY_sv(entry), len);
2267 *retlen = HeKLEN(entry);
2268 return HeKEY(entry);
2272 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2274 =for apidoc hv_iterkeysv
2276 Returns the key as an C<SV*> from the current position of the hash
2277 iterator. The return value will always be a mortal copy of the key. Also
2284 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2286 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2288 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2292 =for apidoc hv_iterval
2294 Returns the value from the current position of the hash iterator. See
2301 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2303 PERL_ARGS_ASSERT_HV_ITERVAL;
2305 if (SvRMAGICAL(hv)) {
2306 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2307 SV* const sv = sv_newmortal();
2308 if (HeKLEN(entry) == HEf_SVKEY)
2309 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2311 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2315 return HeVAL(entry);
2319 =for apidoc hv_iternextsv
2321 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2328 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2330 HE * const he = hv_iternext_flags(hv, 0);
2332 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2336 *key = hv_iterkey(he, retlen);
2337 return hv_iterval(hv, he);
2344 =for apidoc hv_magic
2346 Adds magic to a hash. See C<sv_magic>.
2351 /* possibly free a shared string if no one has access to it
2352 * len and hash must both be valid for str.
2355 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2357 unshare_hek_or_pvn (NULL, str, len, hash);
2362 Perl_unshare_hek(pTHX_ HEK *hek)
2365 unshare_hek_or_pvn(hek, NULL, 0, 0);
2368 /* possibly free a shared string if no one has access to it
2369 hek if non-NULL takes priority over the other 3, else str, len and hash
2370 are used. If so, len and hash must both be valid for str.
2373 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2376 register XPVHV* xhv;
2378 register HE **oentry;
2380 bool is_utf8 = FALSE;
2382 const char * const save = str;
2383 struct shared_he *he = NULL;
2386 /* Find the shared he which is just before us in memory. */
2387 he = (struct shared_he *)(((char *)hek)
2388 - STRUCT_OFFSET(struct shared_he,
2391 /* Assert that the caller passed us a genuine (or at least consistent)
2393 assert (he->shared_he_he.hent_hek == hek);
2395 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2396 --he->shared_he_he.he_valu.hent_refcount;
2400 hash = HEK_HASH(hek);
2401 } else if (len < 0) {
2402 STRLEN tmplen = -len;
2404 /* See the note in hv_fetch(). --jhi */
2405 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2408 k_flags = HVhek_UTF8;
2410 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2413 /* what follows was the moral equivalent of:
2414 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2416 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2418 xhv = (XPVHV*)SvANY(PL_strtab);
2419 /* assert(xhv_array != 0) */
2420 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2422 const HE *const he_he = &(he->shared_he_he);
2423 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2428 const int flags_masked = k_flags & HVhek_MASK;
2429 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2430 if (HeHASH(entry) != hash) /* strings can't be equal */
2432 if (HeKLEN(entry) != len)
2434 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2436 if (HeKFLAGS(entry) != flags_masked)
2443 if (--entry->he_valu.hent_refcount == 0) {
2444 *oentry = HeNEXT(entry);
2446 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2451 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2452 "Attempt to free non-existent shared string '%s'%s"
2454 hek ? HEK_KEY(hek) : str,
2455 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2456 if (k_flags & HVhek_FREEKEY)
2460 /* get a (constant) string ptr from the global string table
2461 * string will get added if it is not already there.
2462 * len and hash must both be valid for str.
2465 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2467 bool is_utf8 = FALSE;
2469 const char * const save = str;
2471 PERL_ARGS_ASSERT_SHARE_HEK;
2474 STRLEN tmplen = -len;
2476 /* See the note in hv_fetch(). --jhi */
2477 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2479 /* If we were able to downgrade here, then than means that we were passed
2480 in a key which only had chars 0-255, but was utf8 encoded. */
2483 /* If we found we were able to downgrade the string to bytes, then
2484 we should flag that it needs upgrading on keys or each. Also flag
2485 that we need share_hek_flags to free the string. */
2487 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2490 return share_hek_flags (str, len, hash, flags);
2494 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2498 const int flags_masked = flags & HVhek_MASK;
2499 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2500 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2502 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2504 /* what follows is the moral equivalent of:
2506 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2507 hv_store(PL_strtab, str, len, NULL, hash);
2509 Can't rehash the shared string table, so not sure if it's worth
2510 counting the number of entries in the linked list
2513 /* assert(xhv_array != 0) */
2514 entry = (HvARRAY(PL_strtab))[hindex];
2515 for (;entry; entry = HeNEXT(entry)) {
2516 if (HeHASH(entry) != hash) /* strings can't be equal */
2518 if (HeKLEN(entry) != len)
2520 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2522 if (HeKFLAGS(entry) != flags_masked)
2528 /* What used to be head of the list.
2529 If this is NULL, then we're the first entry for this slot, which
2530 means we need to increate fill. */
2531 struct shared_he *new_entry;
2534 HE **const head = &HvARRAY(PL_strtab)[hindex];
2535 HE *const next = *head;
2537 /* We don't actually store a HE from the arena and a regular HEK.
2538 Instead we allocate one chunk of memory big enough for both,
2539 and put the HEK straight after the HE. This way we can find the
2540 HEK directly from the HE.
2543 Newx(k, STRUCT_OFFSET(struct shared_he,
2544 shared_he_hek.hek_key[0]) + len + 2, char);
2545 new_entry = (struct shared_he *)k;
2546 entry = &(new_entry->shared_he_he);
2547 hek = &(new_entry->shared_he_hek);
2549 Copy(str, HEK_KEY(hek), len, char);
2550 HEK_KEY(hek)[len] = 0;
2552 HEK_HASH(hek) = hash;
2553 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2555 /* Still "point" to the HEK, so that other code need not know what
2557 HeKEY_hek(entry) = hek;
2558 entry->he_valu.hent_refcount = 0;
2559 HeNEXT(entry) = next;
2562 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2563 if (!next) { /* initial entry? */
2564 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2569 ++entry->he_valu.hent_refcount;
2571 if (flags & HVhek_FREEKEY)
2574 return HeKEY_hek(entry);
2578 Perl_hv_placeholders_p(pTHX_ HV *hv)
2581 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2583 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2586 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2589 Perl_die(aTHX_ "panic: hv_placeholders_p");
2592 return &(mg->mg_len);
2597 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2600 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2602 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2604 return mg ? mg->mg_len : 0;
2608 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2611 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2613 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2618 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2619 Perl_die(aTHX_ "panic: hv_placeholders_set");
2621 /* else we don't need to add magic to record 0 placeholders. */
2625 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2630 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2632 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2637 value = &PL_sv_placeholder;
2640 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2643 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2646 case HVrhek_PV_UTF8:
2647 /* Create a string SV that directly points to the bytes in our
2649 value = newSV_type(SVt_PV);
2650 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2651 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2652 /* This stops anything trying to free it */
2653 SvLEN_set(value, 0);
2655 SvREADONLY_on(value);
2656 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2660 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2661 he->refcounted_he_data[0]);
2667 =for apidoc refcounted_he_chain_2hv
2669 Generates and returns a C<HV *> by walking up the tree starting at the passed
2670 in C<struct refcounted_he *>.
2675 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2679 U32 placeholders = 0;
2680 /* We could chase the chain once to get an idea of the number of keys,
2681 and call ksplit. But for now we'll make a potentially inefficient
2682 hash with only 8 entries in its array. */
2683 const U32 max = HvMAX(hv);
2687 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2688 HvARRAY(hv) = (HE**)array;
2693 U32 hash = chain->refcounted_he_hash;
2695 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2697 HE **oentry = &((HvARRAY(hv))[hash & max]);
2698 HE *entry = *oentry;
2701 for (; entry; entry = HeNEXT(entry)) {
2702 if (HeHASH(entry) == hash) {
2703 /* We might have a duplicate key here. If so, entry is older
2704 than the key we've already put in the hash, so if they are
2705 the same, skip adding entry. */
2707 const STRLEN klen = HeKLEN(entry);
2708 const char *const key = HeKEY(entry);
2709 if (klen == chain->refcounted_he_keylen
2710 && (!!HeKUTF8(entry)
2711 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2712 && memEQ(key, REF_HE_KEY(chain), klen))
2715 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2717 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2718 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2719 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2730 = share_hek_flags(REF_HE_KEY(chain),
2731 chain->refcounted_he_keylen,
2732 chain->refcounted_he_hash,
2733 (chain->refcounted_he_data[0]
2734 & (HVhek_UTF8|HVhek_WASUTF8)));
2736 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2738 value = refcounted_he_value(chain);
2739 if (value == &PL_sv_placeholder)
2741 HeVAL(entry) = value;
2743 /* Link it into the chain. */
2744 HeNEXT(entry) = *oentry;
2750 chain = chain->refcounted_he_next;
2754 clear_placeholders(hv, placeholders);
2755 HvTOTALKEYS(hv) -= placeholders;
2758 /* We could check in the loop to see if we encounter any keys with key
2759 flags, but it's probably not worth it, as this per-hash flag is only
2760 really meant as an optimisation for things like Storable. */
2762 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2768 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2769 const char *key, STRLEN klen, int flags, U32 hash)
2772 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2773 of your key has to exactly match that which is stored. */
2774 SV *value = &PL_sv_placeholder;
2777 /* No point in doing any of this if there's nothing to find. */
2781 if (flags & HVhek_FREEKEY)
2783 key = SvPV_const(keysv, klen);
2785 is_utf8 = (SvUTF8(keysv) != 0);
2787 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2791 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2792 hash = SvSHARED_HASH(keysv);
2794 PERL_HASH(hash, key, klen);
2798 for (; chain; chain = chain->refcounted_he_next) {
2800 if (hash != chain->refcounted_he_hash)
2802 if (klen != chain->refcounted_he_keylen)
2804 if (memNE(REF_HE_KEY(chain),key,klen))
2806 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2809 if (hash != HEK_HASH(chain->refcounted_he_hek))
2811 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2813 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2815 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2819 value = sv_2mortal(refcounted_he_value(chain));
2824 if (flags & HVhek_FREEKEY)
2831 =for apidoc refcounted_he_new
2833 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2834 stored in a compact form, all references remain the property of the caller.
2835 The C<struct refcounted_he> is returned with a reference count of 1.
2840 struct refcounted_he *
2841 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2842 SV *const key, SV *const value) {
2845 const char *key_p = SvPV_const(key, key_len);
2846 STRLEN value_len = 0;
2847 const char *value_p = NULL;
2850 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2853 value_type = HVrhek_PV;
2854 } else if (SvIOK(value)) {
2855 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2856 } else if (value == &PL_sv_placeholder) {
2857 value_type = HVrhek_delete;
2858 } else if (!SvOK(value)) {
2859 value_type = HVrhek_undef;
2861 value_type = HVrhek_PV;
2864 if (value_type == HVrhek_PV) {
2865 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2866 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2867 value_p = SvPV_const(value, value_len);
2869 value_type = HVrhek_PV_UTF8;
2874 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2875 As we're going to be building hash keys from this value in future,
2876 normalise it now. */
2877 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2878 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2881 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2882 ((value_type == HVrhek_PV
2883 || value_type == HVrhek_PV_UTF8) ?
2884 (void *)value_p : (void *)value),
2888 static struct refcounted_he *
2889 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2890 const char *const key_p, const STRLEN key_len,
2891 const char flags, char value_type,
2892 const void *value, const STRLEN value_len) {
2894 struct refcounted_he *he;
2896 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2897 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2899 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2902 he = (struct refcounted_he*)
2903 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2907 he = (struct refcounted_he*)
2908 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2912 he->refcounted_he_next = parent;
2915 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2916 he->refcounted_he_val.refcounted_he_u_len = value_len;
2917 } else if (value_type == HVrhek_IV) {
2918 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2919 } else if (value_type == HVrhek_UV) {
2920 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2923 PERL_HASH(hash, key_p, key_len);
2926 he->refcounted_he_hash = hash;
2927 he->refcounted_he_keylen = key_len;
2928 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2930 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2933 if (flags & HVhek_WASUTF8) {
2934 /* If it was downgraded from UTF-8, then the pointer returned from
2935 bytes_from_utf8 is an allocated pointer that we must free. */
2939 he->refcounted_he_data[0] = flags;
2940 he->refcounted_he_refcnt = 1;
2946 =for apidoc refcounted_he_free
2948 Decrements the reference count of the passed in C<struct refcounted_he *>
2949 by one. If the reference count reaches zero the structure's memory is freed,
2950 and C<refcounted_he_free> iterates onto the parent node.
2956 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2958 PERL_UNUSED_CONTEXT;
2961 struct refcounted_he *copy;
2965 new_count = --he->refcounted_he_refcnt;
2966 HINTS_REFCNT_UNLOCK;
2972 #ifndef USE_ITHREADS
2973 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2976 he = he->refcounted_he_next;
2977 PerlMemShared_free(copy);
2981 /* pp_entereval is aware that labels are stored with a key ':' at the top of
2984 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2989 if (chain->refcounted_he_keylen != 1)
2991 if (*REF_HE_KEY(chain) != ':')
2994 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2996 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
2999 /* Stop anyone trying to really mess us up by adding their own value for
3001 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3002 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3006 *len = chain->refcounted_he_val.refcounted_he_u_len;
3008 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3009 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3011 return chain->refcounted_he_data + 1;
3014 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
3015 that interface. Once it works out how to pass in length and UTF-8 ness, this
3016 function will need superseding. */
3017 struct refcounted_he *
3018 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
3020 PERL_ARGS_ASSERT_STORE_COP_LABEL;
3022 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
3023 label, strlen(label));
3027 =for apidoc hv_assert
3029 Check that a hash is in an internally consistent state.
3037 Perl_hv_assert(pTHX_ HV *hv)
3042 int placeholders = 0;
3045 const I32 riter = HvRITER_get(hv);
3046 HE *eiter = HvEITER_get(hv);
3048 PERL_ARGS_ASSERT_HV_ASSERT;
3050 (void)hv_iterinit(hv);
3052 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3053 /* sanity check the values */
3054 if (HeVAL(entry) == &PL_sv_placeholder)
3058 /* sanity check the keys */
3059 if (HeSVKEY(entry)) {
3060 NOOP; /* Don't know what to check on SV keys. */
3061 } else if (HeKUTF8(entry)) {
3063 if (HeKWASUTF8(entry)) {
3064 PerlIO_printf(Perl_debug_log,
3065 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3066 (int) HeKLEN(entry), HeKEY(entry));
3069 } else if (HeKWASUTF8(entry))
3072 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3073 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3074 const int nhashkeys = HvUSEDKEYS(hv);
3075 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3077 if (nhashkeys != real) {
3078 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3081 if (nhashplaceholders != placeholders) {
3082 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3086 if (withflags && ! HvHASKFLAGS(hv)) {
3087 PerlIO_printf(Perl_debug_log,
3088 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3093 sv_dump(MUTABLE_SV(hv));
3095 HvRITER_set(hv, riter); /* Restore hash iterator state */
3096 HvEITER_set(hv, eiter);
3103 * c-indentation-style: bsd
3105 * indent-tabs-mode: t
3108 * ex: set ts=8 sts=4 sw=4 noet: