3 * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
4 * 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 by Larry Wall and others
6 * You may distribute under the terms of either the GNU General Public
7 * License or the Artistic License, as specified in the README file.
12 * I sit beside the fire and think
13 * of all that I have seen.
16 * [p.278 of _The Lord of the Rings_, II/iii: "The Ring Goes South"]
20 =head1 Hash Manipulation Functions
22 A HV structure represents a Perl hash. It consists mainly of an array
23 of pointers, each of which points to a linked list of HE structures. The
24 array is indexed by the hash function of the key, so each linked list
25 represents all the hash entries with the same hash value. Each HE contains
26 a pointer to the actual value, plus a pointer to a HEK structure which
27 holds the key and hash value.
35 #define PERL_HASH_INTERNAL_ACCESS
38 #define HV_MAX_LENGTH_BEFORE_SPLIT 14
40 static const char S_strtab_error[]
41 = "Cannot modify shared string table in hv_%s";
47 /* We could generate this at compile time via (another) auxiliary C
49 const size_t arena_size = Perl_malloc_good_size(PERL_ARENA_SIZE);
50 HE* he = (HE*) Perl_get_arena(aTHX_ arena_size, HE_SVSLOT);
51 HE * const heend = &he[arena_size / sizeof(HE) - 1];
53 PL_body_roots[HE_SVSLOT] = he;
55 HeNEXT(he) = (HE*)(he + 1);
63 #define new_HE() (HE*)safemalloc(sizeof(HE))
64 #define del_HE(p) safefree((char*)p)
73 void ** const root = &PL_body_roots[HE_SVSLOT];
83 #define new_HE() new_he()
86 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
87 PL_body_roots[HE_SVSLOT] = p; \
95 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
97 const int flags_masked = flags & HVhek_MASK;
101 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
103 Newx(k, HEK_BASESIZE + len + 2, char);
105 Copy(str, HEK_KEY(hek), len, char);
106 HEK_KEY(hek)[len] = 0;
108 HEK_HASH(hek) = hash;
109 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
111 if (flags & HVhek_FREEKEY)
116 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
120 Perl_free_tied_hv_pool(pTHX)
123 HE *he = PL_hv_fetch_ent_mh;
126 Safefree(HeKEY_hek(he));
130 PL_hv_fetch_ent_mh = NULL;
133 #if defined(USE_ITHREADS)
135 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
139 PERL_ARGS_ASSERT_HEK_DUP;
140 PERL_UNUSED_ARG(param);
145 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
147 /* We already shared this hash key. */
148 (void)share_hek_hek(shared);
152 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
153 HEK_HASH(source), HEK_FLAGS(source));
154 ptr_table_store(PL_ptr_table, source, shared);
160 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
164 PERL_ARGS_ASSERT_HE_DUP;
168 /* look for it in the table first */
169 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
173 /* create anew and remember what it is */
175 ptr_table_store(PL_ptr_table, e, ret);
177 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
178 if (HeKLEN(e) == HEf_SVKEY) {
180 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
181 HeKEY_hek(ret) = (HEK*)k;
182 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
185 /* This is hek_dup inlined, which seems to be important for speed
187 HEK * const source = HeKEY_hek(e);
188 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
191 /* We already shared this hash key. */
192 (void)share_hek_hek(shared);
196 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
197 HEK_HASH(source), HEK_FLAGS(source));
198 ptr_table_store(PL_ptr_table, source, shared);
200 HeKEY_hek(ret) = shared;
203 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
205 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
208 #endif /* USE_ITHREADS */
211 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
214 SV * const sv = sv_newmortal();
216 PERL_ARGS_ASSERT_HV_NOTALLOWED;
218 if (!(flags & HVhek_FREEKEY)) {
219 sv_setpvn(sv, key, klen);
222 /* Need to free saved eventually assign to mortal SV */
223 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
224 sv_usepvn(sv, (char *) key, klen);
226 if (flags & HVhek_UTF8) {
229 Perl_croak(aTHX_ msg, SVfARG(sv));
232 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
238 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
239 the length of the key. The C<hash> parameter is the precomputed hash
240 value; if it is zero then Perl will compute it. The return value will be
241 NULL if the operation failed or if the value did not need to be actually
242 stored within the hash (as in the case of tied hashes). Otherwise it can
243 be dereferenced to get the original C<SV*>. Note that the caller is
244 responsible for suitably incrementing the reference count of C<val> before
245 the call, and decrementing it if the function returned NULL. Effectively
246 a successful hv_store takes ownership of one reference to C<val>. This is
247 usually what you want; a newly created SV has a reference count of one, so
248 if all your code does is create SVs then store them in a hash, hv_store
249 will own the only reference to the new SV, and your code doesn't need to do
250 anything further to tidy up. hv_store is not implemented as a call to
251 hv_store_ent, and does not create a temporary SV for the key, so if your
252 key data is not already in SV form then use hv_store in preference to
255 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
256 information on how to use this function on tied hashes.
258 =for apidoc hv_store_ent
260 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
261 parameter is the precomputed hash value; if it is zero then Perl will
262 compute it. The return value is the new hash entry so created. It will be
263 NULL if the operation failed or if the value did not need to be actually
264 stored within the hash (as in the case of tied hashes). Otherwise the
265 contents of the return value can be accessed using the C<He?> macros
266 described here. Note that the caller is responsible for suitably
267 incrementing the reference count of C<val> before the call, and
268 decrementing it if the function returned NULL. Effectively a successful
269 hv_store_ent takes ownership of one reference to C<val>. This is
270 usually what you want; a newly created SV has a reference count of one, so
271 if all your code does is create SVs then store them in a hash, hv_store
272 will own the only reference to the new SV, and your code doesn't need to do
273 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
274 unlike C<val> it does not take ownership of it, so maintaining the correct
275 reference count on C<key> is entirely the caller's responsibility. hv_store
276 is not implemented as a call to hv_store_ent, and does not create a temporary
277 SV for the key, so if your key data is not already in SV form then use
278 hv_store in preference to hv_store_ent.
280 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
281 information on how to use this function on tied hashes.
283 =for apidoc hv_exists
285 Returns a boolean indicating whether the specified hash key exists. The
286 C<klen> is the length of the key.
290 Returns the SV which corresponds to the specified key in the hash. The
291 C<klen> is the length of the key. If C<lval> is set then the fetch will be
292 part of a store. Check that the return value is non-null before
293 dereferencing it to an C<SV*>.
295 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
296 information on how to use this function on tied hashes.
298 =for apidoc hv_exists_ent
300 Returns a boolean indicating whether the specified hash key exists. C<hash>
301 can be a valid precomputed hash value, or 0 to ask for it to be
307 /* returns an HE * structure with the all fields set */
308 /* note that hent_val will be a mortal sv for MAGICAL hashes */
310 =for apidoc hv_fetch_ent
312 Returns the hash entry which corresponds to the specified key in the hash.
313 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
314 if you want the function to compute it. IF C<lval> is set then the fetch
315 will be part of a store. Make sure the return value is non-null before
316 accessing it. The return value when C<tb> is a tied hash is a pointer to a
317 static location, so be sure to make a copy of the structure if you need to
320 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
321 information on how to use this function on tied hashes.
326 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
328 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
329 const int action, SV *val, const U32 hash)
334 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
343 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
347 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
348 int flags, int action, SV *val, register U32 hash)
357 const int return_svp = action & HV_FETCH_JUST_SV;
361 if (SvTYPE(hv) == SVTYPEMASK)
364 assert(SvTYPE(hv) == SVt_PVHV);
366 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
368 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
369 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
370 if (uf->uf_set == NULL) {
371 SV* obj = mg->mg_obj;
374 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
375 ((flags & HVhek_UTF8)
379 mg->mg_obj = keysv; /* pass key */
380 uf->uf_index = action; /* pass action */
381 magic_getuvar(MUTABLE_SV(hv), mg);
382 keysv = mg->mg_obj; /* may have changed */
385 /* If the key may have changed, then we need to invalidate
386 any passed-in computed hash value. */
392 if (flags & HVhek_FREEKEY)
394 key = SvPV_const(keysv, klen);
395 is_utf8 = (SvUTF8(keysv) != 0);
396 if (SvIsCOW_shared_hash(keysv)) {
397 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
402 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
405 if (action & HV_DELETE) {
406 return (void *) hv_delete_common(hv, keysv, key, klen,
407 flags | (is_utf8 ? HVhek_UTF8 : 0),
411 xhv = (XPVHV*)SvANY(hv);
413 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
414 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
415 || SvGMAGICAL((const SV *)hv))
417 /* FIXME should be able to skimp on the HE/HEK here when
418 HV_FETCH_JUST_SV is true. */
420 keysv = newSVpvn_utf8(key, klen, is_utf8);
422 keysv = newSVsv(keysv);
425 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
427 /* grab a fake HE/HEK pair from the pool or make a new one */
428 entry = PL_hv_fetch_ent_mh;
430 PL_hv_fetch_ent_mh = HeNEXT(entry);
434 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
435 HeKEY_hek(entry) = (HEK*)k;
437 HeNEXT(entry) = NULL;
438 HeSVKEY_set(entry, keysv);
440 sv_upgrade(sv, SVt_PVLV);
442 /* so we can free entry when freeing sv */
443 LvTARG(sv) = MUTABLE_SV(entry);
445 /* XXX remove at some point? */
446 if (flags & HVhek_FREEKEY)
450 return entry ? (void *) &HeVAL(entry) : NULL;
452 return (void *) entry;
454 #ifdef ENV_IS_CASELESS
455 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
457 for (i = 0; i < klen; ++i)
458 if (isLOWER(key[i])) {
459 /* Would be nice if we had a routine to do the
460 copy and upercase in a single pass through. */
461 const char * const nkey = strupr(savepvn(key,klen));
462 /* Note that this fetch is for nkey (the uppercased
463 key) whereas the store is for key (the original) */
464 void *result = hv_common(hv, NULL, nkey, klen,
465 HVhek_FREEKEY, /* free nkey */
466 0 /* non-LVAL fetch */
467 | HV_DISABLE_UVAR_XKEY
470 0 /* compute hash */);
471 if (!result && (action & HV_FETCH_LVALUE)) {
472 /* This call will free key if necessary.
473 Do it this way to encourage compiler to tail
475 result = hv_common(hv, keysv, key, klen, flags,
477 | HV_DISABLE_UVAR_XKEY
481 if (flags & HVhek_FREEKEY)
489 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
490 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
491 || SvGMAGICAL((const SV *)hv)) {
492 /* I don't understand why hv_exists_ent has svret and sv,
493 whereas hv_exists only had one. */
494 SV * const svret = sv_newmortal();
497 if (keysv || is_utf8) {
499 keysv = newSVpvn_utf8(key, klen, TRUE);
501 keysv = newSVsv(keysv);
503 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
505 mg_copy(MUTABLE_SV(hv), sv, key, klen);
507 if (flags & HVhek_FREEKEY)
509 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
510 /* This cast somewhat evil, but I'm merely using NULL/
511 not NULL to return the boolean exists.
512 And I know hv is not NULL. */
513 return SvTRUE(svret) ? (void *)hv : NULL;
515 #ifdef ENV_IS_CASELESS
516 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
517 /* XXX This code isn't UTF8 clean. */
518 char * const keysave = (char * const)key;
519 /* Will need to free this, so set FREEKEY flag. */
520 key = savepvn(key,klen);
521 key = (const char*)strupr((char*)key);
526 if (flags & HVhek_FREEKEY) {
529 flags |= HVhek_FREEKEY;
533 else if (action & HV_FETCH_ISSTORE) {
536 hv_magic_check (hv, &needs_copy, &needs_store);
538 const bool save_taint = PL_tainted;
539 if (keysv || is_utf8) {
541 keysv = newSVpvn_utf8(key, klen, TRUE);
544 PL_tainted = SvTAINTED(keysv);
545 keysv = sv_2mortal(newSVsv(keysv));
546 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
548 mg_copy(MUTABLE_SV(hv), val, key, klen);
551 TAINT_IF(save_taint);
553 if (flags & HVhek_FREEKEY)
557 #ifdef ENV_IS_CASELESS
558 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
559 /* XXX This code isn't UTF8 clean. */
560 const char *keysave = key;
561 /* Will need to free this, so set FREEKEY flag. */
562 key = savepvn(key,klen);
563 key = (const char*)strupr((char*)key);
568 if (flags & HVhek_FREEKEY) {
571 flags |= HVhek_FREEKEY;
579 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
580 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
581 || (SvRMAGICAL((const SV *)hv)
582 && mg_find((const SV *)hv, PERL_MAGIC_env))
587 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
589 HvARRAY(hv) = (HE**)array;
591 #ifdef DYNAMIC_ENV_FETCH
592 else if (action & HV_FETCH_ISEXISTS) {
593 /* for an %ENV exists, if we do an insert it's by a recursive
594 store call, so avoid creating HvARRAY(hv) right now. */
598 /* XXX remove at some point? */
599 if (flags & HVhek_FREEKEY)
606 if (is_utf8 & !(flags & HVhek_KEYCANONICAL)) {
607 char * const keysave = (char *)key;
608 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
612 flags &= ~HVhek_UTF8;
613 if (key != keysave) {
614 if (flags & HVhek_FREEKEY)
616 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
617 /* If the caller calculated a hash, it was on the sequence of
618 octets that are the UTF-8 form. We've now changed the sequence
619 of octets stored to that of the equivalent byte representation,
620 so the hash we need is different. */
626 PERL_HASH_INTERNAL(hash, key, klen);
627 /* We don't have a pointer to the hv, so we have to replicate the
628 flag into every HEK, so that hv_iterkeysv can see it. */
629 /* And yes, you do need this even though you are not "storing" because
630 you can flip the flags below if doing an lval lookup. (And that
631 was put in to give the semantics Andreas was expecting.) */
632 flags |= HVhek_REHASH;
634 if (keysv && (SvIsCOW_shared_hash(keysv))) {
635 hash = SvSHARED_HASH(keysv);
637 PERL_HASH(hash, key, klen);
641 masked_flags = (flags & HVhek_MASK);
643 #ifdef DYNAMIC_ENV_FETCH
644 if (!HvARRAY(hv)) entry = NULL;
648 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
650 for (; entry; entry = HeNEXT(entry)) {
651 if (HeHASH(entry) != hash) /* strings can't be equal */
653 if (HeKLEN(entry) != (I32)klen)
655 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
657 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
660 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
661 if (HeKFLAGS(entry) != masked_flags) {
662 /* We match if HVhek_UTF8 bit in our flags and hash key's
663 match. But if entry was set previously with HVhek_WASUTF8
664 and key now doesn't (or vice versa) then we should change
665 the key's flag, as this is assignment. */
666 if (HvSHAREKEYS(hv)) {
667 /* Need to swap the key we have for a key with the flags we
668 need. As keys are shared we can't just write to the
669 flag, so we share the new one, unshare the old one. */
670 HEK * const new_hek = share_hek_flags(key, klen, hash,
672 unshare_hek (HeKEY_hek(entry));
673 HeKEY_hek(entry) = new_hek;
675 else if (hv == PL_strtab) {
676 /* PL_strtab is usually the only hash without HvSHAREKEYS,
677 so putting this test here is cheap */
678 if (flags & HVhek_FREEKEY)
680 Perl_croak(aTHX_ S_strtab_error,
681 action & HV_FETCH_LVALUE ? "fetch" : "store");
684 HeKFLAGS(entry) = masked_flags;
685 if (masked_flags & HVhek_ENABLEHVKFLAGS)
688 if (HeVAL(entry) == &PL_sv_placeholder) {
689 /* yes, can store into placeholder slot */
690 if (action & HV_FETCH_LVALUE) {
692 /* This preserves behaviour with the old hv_fetch
693 implementation which at this point would bail out
694 with a break; (at "if we find a placeholder, we
695 pretend we haven't found anything")
697 That break mean that if a placeholder were found, it
698 caused a call into hv_store, which in turn would
699 check magic, and if there is no magic end up pretty
700 much back at this point (in hv_store's code). */
703 /* LVAL fetch which actaully needs a store. */
705 HvPLACEHOLDERS(hv)--;
708 if (val != &PL_sv_placeholder)
709 HvPLACEHOLDERS(hv)--;
712 } else if (action & HV_FETCH_ISSTORE) {
713 SvREFCNT_dec(HeVAL(entry));
716 } else if (HeVAL(entry) == &PL_sv_placeholder) {
717 /* if we find a placeholder, we pretend we haven't found
721 if (flags & HVhek_FREEKEY)
724 return entry ? (void *) &HeVAL(entry) : NULL;
728 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
729 if (!(action & HV_FETCH_ISSTORE)
730 && SvRMAGICAL((const SV *)hv)
731 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
733 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
735 sv = newSVpvn(env,len);
737 return hv_common(hv, keysv, key, klen, flags,
738 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
744 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
745 hv_notallowed(flags, key, klen,
746 "Attempt to access disallowed key '%"SVf"' in"
747 " a restricted hash");
749 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
750 /* Not doing some form of store, so return failure. */
751 if (flags & HVhek_FREEKEY)
755 if (action & HV_FETCH_LVALUE) {
758 /* At this point the old hv_fetch code would call to hv_store,
759 which in turn might do some tied magic. So we need to make that
760 magic check happen. */
761 /* gonna assign to this, so it better be there */
762 /* If a fetch-as-store fails on the fetch, then the action is to
763 recurse once into "hv_store". If we didn't do this, then that
764 recursive call would call the key conversion routine again.
765 However, as we replace the original key with the converted
766 key, this would result in a double conversion, which would show
767 up as a bug if the conversion routine is not idempotent. */
768 return hv_common(hv, keysv, key, klen, flags,
769 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
771 /* XXX Surely that could leak if the fetch-was-store fails?
772 Just like the hv_fetch. */
776 /* Welcome to hv_store... */
779 /* Not sure if we can get here. I think the only case of oentry being
780 NULL is for %ENV with dynamic env fetch. But that should disappear
781 with magic in the previous code. */
784 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
786 HvARRAY(hv) = (HE**)array;
789 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
792 /* share_hek_flags will do the free for us. This might be considered
795 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
796 else if (hv == PL_strtab) {
797 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
798 this test here is cheap */
799 if (flags & HVhek_FREEKEY)
801 Perl_croak(aTHX_ S_strtab_error,
802 action & HV_FETCH_LVALUE ? "fetch" : "store");
804 else /* gotta do the real thing */
805 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
807 HeNEXT(entry) = *oentry;
810 if (val == &PL_sv_placeholder)
811 HvPLACEHOLDERS(hv)++;
812 if (masked_flags & HVhek_ENABLEHVKFLAGS)
816 const HE *counter = HeNEXT(entry);
818 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
819 if (!counter) { /* initial entry? */
820 } else if (xhv->xhv_keys > xhv->xhv_max) {
822 } else if(!HvREHASH(hv)) {
825 while ((counter = HeNEXT(counter)))
828 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
829 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
830 bucket splits on a rehashed hash, as we're not going to
831 split it again, and if someone is lucky (evil) enough to
832 get all the keys in one list they could exhaust our memory
833 as we repeatedly double the number of buckets on every
834 entry. Linear search feels a less worse thing to do. */
841 return entry ? (void *) &HeVAL(entry) : NULL;
843 return (void *) entry;
847 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
849 const MAGIC *mg = SvMAGIC(hv);
851 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
856 if (isUPPER(mg->mg_type)) {
858 if (mg->mg_type == PERL_MAGIC_tied) {
859 *needs_store = FALSE;
860 return; /* We've set all there is to set. */
863 mg = mg->mg_moremagic;
868 =for apidoc hv_scalar
870 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
876 Perl_hv_scalar(pTHX_ HV *hv)
880 PERL_ARGS_ASSERT_HV_SCALAR;
882 if (SvRMAGICAL(hv)) {
883 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
885 return magic_scalarpack(hv, mg);
889 if (HvTOTALKEYS((const HV *)hv))
890 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
891 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
899 =for apidoc hv_delete
901 Deletes a key/value pair in the hash. The value SV is removed from the
902 hash and returned to the caller. The C<klen> is the length of the key.
903 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
906 =for apidoc hv_delete_ent
908 Deletes a key/value pair in the hash. The value SV is removed from the
909 hash and returned to the caller. The C<flags> value will normally be zero;
910 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
911 precomputed hash value, or 0 to ask for it to be computed.
917 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
918 int k_flags, I32 d_flags, U32 hash)
923 register HE **oentry;
924 HE *const *first_entry;
925 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
928 if (SvRMAGICAL(hv)) {
931 hv_magic_check (hv, &needs_copy, &needs_store);
935 entry = (HE *) hv_common(hv, keysv, key, klen,
936 k_flags & ~HVhek_FREEKEY,
937 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
939 sv = entry ? HeVAL(entry) : NULL;
945 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
946 /* No longer an element */
947 sv_unmagic(sv, PERL_MAGIC_tiedelem);
950 return NULL; /* element cannot be deleted */
952 #ifdef ENV_IS_CASELESS
953 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
954 /* XXX This code isn't UTF8 clean. */
955 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
956 if (k_flags & HVhek_FREEKEY) {
959 key = strupr(SvPVX(keysv));
968 xhv = (XPVHV*)SvANY(hv);
973 const char * const keysave = key;
974 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
977 k_flags |= HVhek_UTF8;
979 k_flags &= ~HVhek_UTF8;
980 if (key != keysave) {
981 if (k_flags & HVhek_FREEKEY) {
982 /* This shouldn't happen if our caller does what we expect,
983 but strictly the API allows it. */
986 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
988 HvHASKFLAGS_on(MUTABLE_SV(hv));
992 PERL_HASH_INTERNAL(hash, key, klen);
994 if (keysv && (SvIsCOW_shared_hash(keysv))) {
995 hash = SvSHARED_HASH(keysv);
997 PERL_HASH(hash, key, klen);
1001 masked_flags = (k_flags & HVhek_MASK);
1003 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
1005 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
1007 if (HeHASH(entry) != hash) /* strings can't be equal */
1009 if (HeKLEN(entry) != (I32)klen)
1011 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
1013 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
1016 if (hv == PL_strtab) {
1017 if (k_flags & HVhek_FREEKEY)
1019 Perl_croak(aTHX_ S_strtab_error, "delete");
1022 /* if placeholder is here, it's already been deleted.... */
1023 if (HeVAL(entry) == &PL_sv_placeholder) {
1024 if (k_flags & HVhek_FREEKEY)
1028 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1029 hv_notallowed(k_flags, key, klen,
1030 "Attempt to delete readonly key '%"SVf"' from"
1031 " a restricted hash");
1033 if (k_flags & HVhek_FREEKEY)
1036 if (d_flags & G_DISCARD)
1039 sv = sv_2mortal(HeVAL(entry));
1040 HeVAL(entry) = &PL_sv_placeholder;
1044 * If a restricted hash, rather than really deleting the entry, put
1045 * a placeholder there. This marks the key as being "approved", so
1046 * we can still access via not-really-existing key without raising
1049 if (SvREADONLY(hv)) {
1050 SvREFCNT_dec(HeVAL(entry));
1051 HeVAL(entry) = &PL_sv_placeholder;
1052 /* We'll be saving this slot, so the number of allocated keys
1053 * doesn't go down, but the number placeholders goes up */
1054 HvPLACEHOLDERS(hv)++;
1056 *oentry = HeNEXT(entry);
1057 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1060 hv_free_ent(hv, entry);
1061 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1062 if (xhv->xhv_keys == 0)
1063 HvHASKFLAGS_off(hv);
1067 if (SvREADONLY(hv)) {
1068 hv_notallowed(k_flags, key, klen,
1069 "Attempt to delete disallowed key '%"SVf"' from"
1070 " a restricted hash");
1073 if (k_flags & HVhek_FREEKEY)
1079 S_hsplit(pTHX_ HV *hv)
1082 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1083 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1084 register I32 newsize = oldsize * 2;
1086 char *a = (char*) HvARRAY(hv);
1088 int longest_chain = 0;
1091 PERL_ARGS_ASSERT_HSPLIT;
1093 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1094 (void*)hv, (int) oldsize);*/
1096 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1097 /* Can make this clear any placeholders first for non-restricted hashes,
1098 even though Storable rebuilds restricted hashes by putting in all the
1099 placeholders (first) before turning on the readonly flag, because
1100 Storable always pre-splits the hash. */
1101 hv_clear_placeholders(hv);
1105 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1106 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1107 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1113 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1116 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1117 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1122 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1124 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1126 if (oldsize >= 64) {
1127 offer_nice_chunk(HvARRAY(hv),
1128 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1129 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1132 Safefree(HvARRAY(hv));
1136 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1137 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1138 HvARRAY(hv) = (HE**) a;
1141 for (i=0; i<oldsize; i++,aep++) {
1142 int left_length = 0;
1143 int right_length = 0;
1148 if (!entry) /* non-existent */
1152 if ((HeHASH(entry) & newsize) != (U32)i) {
1153 *oentry = HeNEXT(entry);
1154 HeNEXT(entry) = *bep;
1159 oentry = &HeNEXT(entry);
1164 /* I think we don't actually need to keep track of the longest length,
1165 merely flag if anything is too long. But for the moment while
1166 developing this code I'll track it. */
1167 if (left_length > longest_chain)
1168 longest_chain = left_length;
1169 if (right_length > longest_chain)
1170 longest_chain = right_length;
1174 /* Pick your policy for "hashing isn't working" here: */
1175 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1180 if (hv == PL_strtab) {
1181 /* Urg. Someone is doing something nasty to the string table.
1186 /* Awooga. Awooga. Pathological data. */
1187 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1188 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1191 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1192 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1194 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1197 was_shared = HvSHAREKEYS(hv);
1199 HvSHAREKEYS_off(hv);
1204 for (i=0; i<newsize; i++,aep++) {
1205 register HE *entry = *aep;
1207 /* We're going to trash this HE's next pointer when we chain it
1208 into the new hash below, so store where we go next. */
1209 HE * const next = HeNEXT(entry);
1214 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1219 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1220 hash, HeKFLAGS(entry));
1221 unshare_hek (HeKEY_hek(entry));
1222 HeKEY_hek(entry) = new_hek;
1224 /* Not shared, so simply write the new hash in. */
1225 HeHASH(entry) = hash;
1227 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1228 HEK_REHASH_on(HeKEY_hek(entry));
1229 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1231 /* Copy oentry to the correct new chain. */
1232 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1233 HeNEXT(entry) = *bep;
1239 Safefree (HvARRAY(hv));
1240 HvARRAY(hv) = (HE **)a;
1244 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1247 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1248 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1249 register I32 newsize;
1254 PERL_ARGS_ASSERT_HV_KSPLIT;
1256 newsize = (I32) newmax; /* possible truncation here */
1257 if (newsize != newmax || newmax <= oldsize)
1259 while ((newsize & (1 + ~newsize)) != newsize) {
1260 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1262 if (newsize < newmax)
1264 if (newsize < newmax)
1265 return; /* overflow detection */
1267 a = (char *) HvARRAY(hv);
1270 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1271 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1272 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1278 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1281 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1282 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1287 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1289 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1291 if (oldsize >= 64) {
1292 offer_nice_chunk(HvARRAY(hv),
1293 PERL_HV_ARRAY_ALLOC_BYTES(oldsize)
1294 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0));
1297 Safefree(HvARRAY(hv));
1300 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1303 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1305 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1306 HvARRAY(hv) = (HE **) a;
1307 if (!xhv->xhv_keys /* !HvTOTALKEYS(hv) */) /* skip rest if no entries */
1311 for (i=0; i<oldsize; i++,aep++) {
1315 if (!entry) /* non-existent */
1318 register I32 j = (HeHASH(entry) & newsize);
1322 *oentry = HeNEXT(entry);
1323 HeNEXT(entry) = aep[j];
1327 oentry = &HeNEXT(entry);
1334 Perl_newHVhv(pTHX_ HV *ohv)
1337 HV * const hv = newHV();
1340 if (!ohv || !HvTOTALKEYS(ohv))
1342 hv_max = HvMAX(ohv);
1344 if (!SvMAGICAL((const SV *)ohv)) {
1345 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1347 const bool shared = !!HvSHAREKEYS(ohv);
1348 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1350 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1353 /* In each bucket... */
1354 for (i = 0; i <= hv_max; i++) {
1356 HE *oent = oents[i];
1363 /* Copy the linked list of entries. */
1364 for (; oent; oent = HeNEXT(oent)) {
1365 const U32 hash = HeHASH(oent);
1366 const char * const key = HeKEY(oent);
1367 const STRLEN len = HeKLEN(oent);
1368 const int flags = HeKFLAGS(oent);
1369 HE * const ent = new_HE();
1370 SV *const val = HeVAL(oent);
1372 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1374 = shared ? share_hek_flags(key, len, hash, flags)
1375 : save_hek_flags(key, len, hash, flags);
1386 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1390 /* Iterate over ohv, copying keys and values one at a time. */
1392 const I32 riter = HvRITER_get(ohv);
1393 HE * const eiter = HvEITER_get(ohv);
1394 STRLEN hv_fill = HvFILL(ohv);
1396 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1397 while (hv_max && hv_max + 1 >= hv_fill * 2)
1398 hv_max = hv_max / 2;
1402 while ((entry = hv_iternext_flags(ohv, 0))) {
1403 SV *const val = HeVAL(entry);
1404 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1405 SvIMMORTAL(val) ? val : newSVsv(val),
1406 HeHASH(entry), HeKFLAGS(entry));
1408 HvRITER_set(ohv, riter);
1409 HvEITER_set(ohv, eiter);
1415 /* A rather specialised version of newHVhv for copying %^H, ensuring all the
1416 magic stays on it. */
1418 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1420 HV * const hv = newHV();
1422 if (ohv && HvTOTALKEYS(ohv)) {
1423 STRLEN hv_max = HvMAX(ohv);
1424 STRLEN hv_fill = HvFILL(ohv);
1426 const I32 riter = HvRITER_get(ohv);
1427 HE * const eiter = HvEITER_get(ohv);
1429 while (hv_max && hv_max + 1 >= hv_fill * 2)
1430 hv_max = hv_max / 2;
1434 while ((entry = hv_iternext_flags(ohv, 0))) {
1435 SV *const sv = newSVsv(HeVAL(entry));
1436 SV *heksv = newSVhek(HeKEY_hek(entry));
1437 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1438 (char *)heksv, HEf_SVKEY);
1439 SvREFCNT_dec(heksv);
1440 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1441 sv, HeHASH(entry), HeKFLAGS(entry));
1443 HvRITER_set(ohv, riter);
1444 HvEITER_set(ohv, eiter);
1446 hv_magic(hv, NULL, PERL_MAGIC_hints);
1451 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1456 PERL_ARGS_ASSERT_HV_FREE_ENT;
1461 if (HvNAME(hv) && anonymise_cv(HvNAME_HEK(hv), val) && GvCVu(val))
1462 mro_method_changed_in(hv);
1464 if (HeKLEN(entry) == HEf_SVKEY) {
1465 SvREFCNT_dec(HeKEY_sv(entry));
1466 Safefree(HeKEY_hek(entry));
1468 else if (HvSHAREKEYS(hv))
1469 unshare_hek(HeKEY_hek(entry));
1471 Safefree(HeKEY_hek(entry));
1476 S_anonymise_cv(pTHX_ HEK *stash, SV *val)
1480 PERL_ARGS_ASSERT_ANONYMISE_CV;
1482 if (val && isGV(val) && isGV_with_GP(val) && (cv = GvCV(val))) {
1483 if ((SV *)CvGV(cv) == val) {
1487 SV *gvname = newSVhek(stash);
1488 sv_catpvs(gvname, "::__ANON__");
1489 anongv = gv_fetchsv(gvname, GV_ADDMULTI, SVt_PVCV);
1490 SvREFCNT_dec(gvname);
1492 anongv = gv_fetchpvs("__ANON__::__ANON__", GV_ADDMULTI,
1504 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1508 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1512 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1513 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1514 if (HeKLEN(entry) == HEf_SVKEY) {
1515 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1517 hv_free_ent(hv, entry);
1521 =for apidoc hv_clear
1523 Clears a hash, making it empty.
1529 Perl_hv_clear(pTHX_ HV *hv)
1532 register XPVHV* xhv;
1536 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1538 xhv = (XPVHV*)SvANY(hv);
1540 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1541 /* restricted hash: convert all keys to placeholders */
1543 for (i = 0; i <= xhv->xhv_max; i++) {
1544 HE *entry = (HvARRAY(hv))[i];
1545 for (; entry; entry = HeNEXT(entry)) {
1546 /* not already placeholder */
1547 if (HeVAL(entry) != &PL_sv_placeholder) {
1548 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1549 SV* const keysv = hv_iterkeysv(entry);
1551 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1554 SvREFCNT_dec(HeVAL(entry));
1555 HeVAL(entry) = &PL_sv_placeholder;
1556 HvPLACEHOLDERS(hv)++;
1564 HvPLACEHOLDERS_set(hv, 0);
1566 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1569 mg_clear(MUTABLE_SV(hv));
1571 HvHASKFLAGS_off(hv);
1576 mro_isa_changed_in(hv);
1577 HvEITER_set(hv, NULL);
1582 =for apidoc hv_clear_placeholders
1584 Clears any placeholders from a hash. If a restricted hash has any of its keys
1585 marked as readonly and the key is subsequently deleted, the key is not actually
1586 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1587 it so it will be ignored by future operations such as iterating over the hash,
1588 but will still allow the hash to have a value reassigned to the key at some
1589 future point. This function clears any such placeholder keys from the hash.
1590 See Hash::Util::lock_keys() for an example of its use.
1596 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1599 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1601 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1604 clear_placeholders(hv, items);
1608 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1613 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1620 /* Loop down the linked list heads */
1622 HE **oentry = &(HvARRAY(hv))[i];
1625 while ((entry = *oentry)) {
1626 if (HeVAL(entry) == &PL_sv_placeholder) {
1627 *oentry = HeNEXT(entry);
1628 if (entry == HvEITER_get(hv))
1631 hv_free_ent(hv, entry);
1635 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1636 if (HvKEYS(hv) == 0)
1637 HvHASKFLAGS_off(hv);
1638 HvPLACEHOLDERS_set(hv, 0);
1642 oentry = &HeNEXT(entry);
1647 /* You can't get here, hence assertion should always fail. */
1648 assert (items == 0);
1653 S_hfreeentries(pTHX_ HV *hv)
1655 /* This is the array that we're going to restore */
1656 HE **const orig_array = HvARRAY(hv);
1660 PERL_ARGS_ASSERT_HFREEENTRIES;
1665 if (HvNAME(hv) && orig_array != NULL) {
1666 /* symbol table: make all the contained subs ANON */
1668 XPVHV *xhv = (XPVHV*)SvANY(hv);
1670 for (i = 0; i <= xhv->xhv_max; i++) {
1671 HE *entry = (HvARRAY(hv))[i];
1672 for (; entry; entry = HeNEXT(entry)) {
1673 SV *val = HeVAL(entry);
1674 /* we need to put the subs in the __ANON__ symtable, as
1675 * this one is being cleared. */
1676 anonymise_cv(NULL, val);
1682 /* If the hash is actually a symbol table with a name, look after the
1684 struct xpvhv_aux *iter = HvAUX(hv);
1686 name = iter->xhv_name;
1687 iter->xhv_name = NULL;
1692 /* orig_array remains unchanged throughout the loop. If after freeing all
1693 the entries it turns out that one of the little blighters has triggered
1694 an action that has caused HvARRAY to be re-allocated, then we set
1695 array to the new HvARRAY, and try again. */
1698 /* This is the one we're going to try to empty. First time round
1699 it's the original array. (Hopefully there will only be 1 time
1701 HE ** const array = HvARRAY(hv);
1704 /* Because we have taken xhv_name out, the only allocated pointer
1705 in the aux structure that might exist is the backreference array.
1710 struct mro_meta *meta;
1711 struct xpvhv_aux *iter = HvAUX(hv);
1712 /* If there are weak references to this HV, we need to avoid
1713 freeing them up here. In particular we need to keep the AV
1714 visible as what we're deleting might well have weak references
1715 back to this HV, so the for loop below may well trigger
1716 the removal of backreferences from this array. */
1718 if (iter->xhv_backreferences) {
1719 /* So donate them to regular backref magic to keep them safe.
1720 The sv_magic will increase the reference count of the AV,
1721 so we need to drop it first. */
1722 SvREFCNT_dec(iter->xhv_backreferences);
1723 if (AvFILLp(iter->xhv_backreferences) == -1) {
1724 /* Turns out that the array is empty. Just free it. */
1725 SvREFCNT_dec(iter->xhv_backreferences);
1728 sv_magic(MUTABLE_SV(hv),
1729 MUTABLE_SV(iter->xhv_backreferences),
1730 PERL_MAGIC_backref, NULL, 0);
1732 iter->xhv_backreferences = NULL;
1735 entry = iter->xhv_eiter; /* HvEITER(hv) */
1736 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1738 hv_free_ent(hv, entry);
1740 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1741 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1743 if((meta = iter->xhv_mro_meta)) {
1744 if (meta->mro_linear_all) {
1745 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1746 meta->mro_linear_all = NULL;
1747 /* This is just acting as a shortcut pointer. */
1748 meta->mro_linear_current = NULL;
1749 } else if (meta->mro_linear_current) {
1750 /* Only the current MRO is stored, so this owns the data.
1752 SvREFCNT_dec(meta->mro_linear_current);
1753 meta->mro_linear_current = NULL;
1755 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1756 SvREFCNT_dec(meta->isa);
1758 iter->xhv_mro_meta = NULL;
1761 /* There are now no allocated pointers in the aux structure. */
1763 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1764 /* What aux structure? */
1767 /* make everyone else think the array is empty, so that the destructors
1768 * called for freed entries can't recusively mess with us */
1770 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1774 /* Loop down the linked list heads */
1775 HE *entry = array[i];
1778 register HE * const oentry = entry;
1779 entry = HeNEXT(entry);
1780 hv_free_ent(hv, oentry);
1784 /* As there are no allocated pointers in the aux structure, it's now
1785 safe to free the array we just cleaned up, if it's not the one we're
1786 going to put back. */
1787 if (array != orig_array) {
1792 /* Good. No-one added anything this time round. */
1797 /* Someone attempted to iterate or set the hash name while we had
1798 the array set to 0. We'll catch backferences on the next time
1799 round the while loop. */
1800 assert(HvARRAY(hv));
1802 if (HvAUX(hv)->xhv_name) {
1803 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1807 if (--attempts == 0) {
1808 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1812 HvARRAY(hv) = orig_array;
1814 /* If the hash was actually a symbol table, put the name back. */
1816 /* We have restored the original array. If name is non-NULL, then
1817 the original array had an aux structure at the end. So this is
1819 SvFLAGS(hv) |= SVf_OOK;
1820 HvAUX(hv)->xhv_name = name;
1825 =for apidoc hv_undef
1833 Perl_hv_undef(pTHX_ HV *hv)
1836 register XPVHV* xhv;
1841 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1842 xhv = (XPVHV*)SvANY(hv);
1844 if ((name = HvNAME_get(hv)) && !PL_dirty)
1845 mro_isa_changed_in(hv);
1850 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1851 hv_name_set(hv, NULL, 0, 0);
1853 SvFLAGS(hv) &= ~SVf_OOK;
1854 Safefree(HvARRAY(hv));
1855 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1857 HvPLACEHOLDERS_set(hv, 0);
1860 mg_clear(MUTABLE_SV(hv));
1866 Returns the number of hash buckets that happen to be in use. This function is
1867 wrapped by the macro C<HvFILL>.
1869 Previously this value was stored in the HV structure, rather than being
1870 calculated on demand.
1876 Perl_hv_fill(pTHX_ HV const *const hv)
1879 HE **ents = HvARRAY(hv);
1881 PERL_ARGS_ASSERT_HV_FILL;
1884 HE *const *const last = ents + HvMAX(hv);
1885 count = last + 1 - ents;
1890 } while (++ents <= last);
1895 static struct xpvhv_aux*
1896 S_hv_auxinit(HV *hv) {
1897 struct xpvhv_aux *iter;
1900 PERL_ARGS_ASSERT_HV_AUXINIT;
1903 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1904 + sizeof(struct xpvhv_aux), char);
1906 array = (char *) HvARRAY(hv);
1907 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1908 + sizeof(struct xpvhv_aux), char);
1910 HvARRAY(hv) = (HE**) array;
1911 /* SvOOK_on(hv) attacks the IV flags. */
1912 SvFLAGS(hv) |= SVf_OOK;
1915 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1916 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1918 iter->xhv_backreferences = 0;
1919 iter->xhv_mro_meta = NULL;
1924 =for apidoc hv_iterinit
1926 Prepares a starting point to traverse a hash table. Returns the number of
1927 keys in the hash (i.e. the same as C<HvKEYS(tb)>). The return value is
1928 currently only meaningful for hashes without tie magic.
1930 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1931 hash buckets that happen to be in use. If you still need that esoteric
1932 value, you can get it through the macro C<HvFILL(tb)>.
1939 Perl_hv_iterinit(pTHX_ HV *hv)
1941 PERL_ARGS_ASSERT_HV_ITERINIT;
1943 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1946 Perl_croak(aTHX_ "Bad hash");
1949 struct xpvhv_aux * const iter = HvAUX(hv);
1950 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1951 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1953 hv_free_ent(hv, entry);
1955 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1956 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1961 /* used to be xhv->xhv_fill before 5.004_65 */
1962 return HvTOTALKEYS(hv);
1966 Perl_hv_riter_p(pTHX_ HV *hv) {
1967 struct xpvhv_aux *iter;
1969 PERL_ARGS_ASSERT_HV_RITER_P;
1972 Perl_croak(aTHX_ "Bad hash");
1974 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1975 return &(iter->xhv_riter);
1979 Perl_hv_eiter_p(pTHX_ HV *hv) {
1980 struct xpvhv_aux *iter;
1982 PERL_ARGS_ASSERT_HV_EITER_P;
1985 Perl_croak(aTHX_ "Bad hash");
1987 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1988 return &(iter->xhv_eiter);
1992 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1993 struct xpvhv_aux *iter;
1995 PERL_ARGS_ASSERT_HV_RITER_SET;
1998 Perl_croak(aTHX_ "Bad hash");
2006 iter = hv_auxinit(hv);
2008 iter->xhv_riter = riter;
2012 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
2013 struct xpvhv_aux *iter;
2015 PERL_ARGS_ASSERT_HV_EITER_SET;
2018 Perl_croak(aTHX_ "Bad hash");
2023 /* 0 is the default so don't go malloc()ing a new structure just to
2028 iter = hv_auxinit(hv);
2030 iter->xhv_eiter = eiter;
2034 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
2037 struct xpvhv_aux *iter;
2040 PERL_ARGS_ASSERT_HV_NAME_SET;
2041 PERL_UNUSED_ARG(flags);
2044 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2048 if (iter->xhv_name) {
2049 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2055 iter = hv_auxinit(hv);
2057 PERL_HASH(hash, name, len);
2058 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2062 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2063 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2065 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2066 PERL_UNUSED_CONTEXT;
2068 return &(iter->xhv_backreferences);
2072 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2075 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2080 av = HvAUX(hv)->xhv_backreferences;
2083 HvAUX(hv)->xhv_backreferences = 0;
2084 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2090 hv_iternext is implemented as a macro in hv.h
2092 =for apidoc hv_iternext
2094 Returns entries from a hash iterator. See C<hv_iterinit>.
2096 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2097 iterator currently points to, without losing your place or invalidating your
2098 iterator. Note that in this case the current entry is deleted from the hash
2099 with your iterator holding the last reference to it. Your iterator is flagged
2100 to free the entry on the next call to C<hv_iternext>, so you must not discard
2101 your iterator immediately else the entry will leak - call C<hv_iternext> to
2102 trigger the resource deallocation.
2104 =for apidoc hv_iternext_flags
2106 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2107 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2108 set the placeholders keys (for restricted hashes) will be returned in addition
2109 to normal keys. By default placeholders are automatically skipped over.
2110 Currently a placeholder is implemented with a value that is
2111 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2112 restricted hashes may change, and the implementation currently is
2113 insufficiently abstracted for any change to be tidy.
2119 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2122 register XPVHV* xhv;
2126 struct xpvhv_aux *iter;
2128 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2131 Perl_croak(aTHX_ "Bad hash");
2133 xhv = (XPVHV*)SvANY(hv);
2136 /* Too many things (well, pp_each at least) merrily assume that you can
2137 call iv_iternext without calling hv_iterinit, so we'll have to deal
2143 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2144 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2145 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2146 SV * const key = sv_newmortal();
2148 sv_setsv(key, HeSVKEY_force(entry));
2149 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2155 /* one HE per MAGICAL hash */
2156 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2158 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2160 HeKEY_hek(entry) = hek;
2161 HeKLEN(entry) = HEf_SVKEY;
2163 magic_nextpack(MUTABLE_SV(hv),mg,key);
2165 /* force key to stay around until next time */
2166 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2167 return entry; /* beware, hent_val is not set */
2169 SvREFCNT_dec(HeVAL(entry));
2170 Safefree(HeKEY_hek(entry));
2172 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2176 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2177 if (!entry && SvRMAGICAL((const SV *)hv)
2178 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2181 /* The prime_env_iter() on VMS just loaded up new hash values
2182 * so the iteration count needs to be reset back to the beginning
2186 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2191 /* hv_iterint now ensures this. */
2192 assert (HvARRAY(hv));
2194 /* At start of hash, entry is NULL. */
2197 entry = HeNEXT(entry);
2198 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2200 * Skip past any placeholders -- don't want to include them in
2203 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2204 entry = HeNEXT(entry);
2209 /* Skip the entire loop if the hash is empty. */
2210 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2211 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2213 /* OK. Come to the end of the current list. Grab the next one. */
2215 iter->xhv_riter++; /* HvRITER(hv)++ */
2216 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2217 /* There is no next one. End of the hash. */
2218 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2221 entry = (HvARRAY(hv))[iter->xhv_riter];
2223 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2224 /* If we have an entry, but it's a placeholder, don't count it.
2226 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2227 entry = HeNEXT(entry);
2229 /* Will loop again if this linked list starts NULL
2230 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2231 or if we run through it and find only placeholders. */
2235 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2237 hv_free_ent(hv, oldentry);
2240 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2241 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2243 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2248 =for apidoc hv_iterkey
2250 Returns the key from the current position of the hash iterator. See
2257 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2259 PERL_ARGS_ASSERT_HV_ITERKEY;
2261 if (HeKLEN(entry) == HEf_SVKEY) {
2263 char * const p = SvPV(HeKEY_sv(entry), len);
2268 *retlen = HeKLEN(entry);
2269 return HeKEY(entry);
2273 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2275 =for apidoc hv_iterkeysv
2277 Returns the key as an C<SV*> from the current position of the hash
2278 iterator. The return value will always be a mortal copy of the key. Also
2285 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2287 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2289 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2293 =for apidoc hv_iterval
2295 Returns the value from the current position of the hash iterator. See
2302 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2304 PERL_ARGS_ASSERT_HV_ITERVAL;
2306 if (SvRMAGICAL(hv)) {
2307 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2308 SV* const sv = sv_newmortal();
2309 if (HeKLEN(entry) == HEf_SVKEY)
2310 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2312 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2316 return HeVAL(entry);
2320 =for apidoc hv_iternextsv
2322 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2329 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2331 HE * const he = hv_iternext_flags(hv, 0);
2333 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2337 *key = hv_iterkey(he, retlen);
2338 return hv_iterval(hv, he);
2345 =for apidoc hv_magic
2347 Adds magic to a hash. See C<sv_magic>.
2352 /* possibly free a shared string if no one has access to it
2353 * len and hash must both be valid for str.
2356 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2358 unshare_hek_or_pvn (NULL, str, len, hash);
2363 Perl_unshare_hek(pTHX_ HEK *hek)
2366 unshare_hek_or_pvn(hek, NULL, 0, 0);
2369 /* possibly free a shared string if no one has access to it
2370 hek if non-NULL takes priority over the other 3, else str, len and hash
2371 are used. If so, len and hash must both be valid for str.
2374 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2377 register XPVHV* xhv;
2379 register HE **oentry;
2381 bool is_utf8 = FALSE;
2383 const char * const save = str;
2384 struct shared_he *he = NULL;
2387 /* Find the shared he which is just before us in memory. */
2388 he = (struct shared_he *)(((char *)hek)
2389 - STRUCT_OFFSET(struct shared_he,
2392 /* Assert that the caller passed us a genuine (or at least consistent)
2394 assert (he->shared_he_he.hent_hek == hek);
2396 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2397 --he->shared_he_he.he_valu.hent_refcount;
2401 hash = HEK_HASH(hek);
2402 } else if (len < 0) {
2403 STRLEN tmplen = -len;
2405 /* See the note in hv_fetch(). --jhi */
2406 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2409 k_flags = HVhek_UTF8;
2411 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2414 /* what follows was the moral equivalent of:
2415 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2417 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2419 xhv = (XPVHV*)SvANY(PL_strtab);
2420 /* assert(xhv_array != 0) */
2421 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2423 const HE *const he_he = &(he->shared_he_he);
2424 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2429 const int flags_masked = k_flags & HVhek_MASK;
2430 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2431 if (HeHASH(entry) != hash) /* strings can't be equal */
2433 if (HeKLEN(entry) != len)
2435 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2437 if (HeKFLAGS(entry) != flags_masked)
2444 if (--entry->he_valu.hent_refcount == 0) {
2445 *oentry = HeNEXT(entry);
2447 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2452 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2453 "Attempt to free non-existent shared string '%s'%s"
2455 hek ? HEK_KEY(hek) : str,
2456 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2457 if (k_flags & HVhek_FREEKEY)
2461 /* get a (constant) string ptr from the global string table
2462 * string will get added if it is not already there.
2463 * len and hash must both be valid for str.
2466 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2468 bool is_utf8 = FALSE;
2470 const char * const save = str;
2472 PERL_ARGS_ASSERT_SHARE_HEK;
2475 STRLEN tmplen = -len;
2477 /* See the note in hv_fetch(). --jhi */
2478 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2480 /* If we were able to downgrade here, then than means that we were passed
2481 in a key which only had chars 0-255, but was utf8 encoded. */
2484 /* If we found we were able to downgrade the string to bytes, then
2485 we should flag that it needs upgrading on keys or each. Also flag
2486 that we need share_hek_flags to free the string. */
2488 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2491 return share_hek_flags (str, len, hash, flags);
2495 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2499 const int flags_masked = flags & HVhek_MASK;
2500 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2501 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2503 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2505 /* what follows is the moral equivalent of:
2507 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2508 hv_store(PL_strtab, str, len, NULL, hash);
2510 Can't rehash the shared string table, so not sure if it's worth
2511 counting the number of entries in the linked list
2514 /* assert(xhv_array != 0) */
2515 entry = (HvARRAY(PL_strtab))[hindex];
2516 for (;entry; entry = HeNEXT(entry)) {
2517 if (HeHASH(entry) != hash) /* strings can't be equal */
2519 if (HeKLEN(entry) != len)
2521 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2523 if (HeKFLAGS(entry) != flags_masked)
2529 /* What used to be head of the list.
2530 If this is NULL, then we're the first entry for this slot, which
2531 means we need to increate fill. */
2532 struct shared_he *new_entry;
2535 HE **const head = &HvARRAY(PL_strtab)[hindex];
2536 HE *const next = *head;
2538 /* We don't actually store a HE from the arena and a regular HEK.
2539 Instead we allocate one chunk of memory big enough for both,
2540 and put the HEK straight after the HE. This way we can find the
2541 HEK directly from the HE.
2544 Newx(k, STRUCT_OFFSET(struct shared_he,
2545 shared_he_hek.hek_key[0]) + len + 2, char);
2546 new_entry = (struct shared_he *)k;
2547 entry = &(new_entry->shared_he_he);
2548 hek = &(new_entry->shared_he_hek);
2550 Copy(str, HEK_KEY(hek), len, char);
2551 HEK_KEY(hek)[len] = 0;
2553 HEK_HASH(hek) = hash;
2554 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2556 /* Still "point" to the HEK, so that other code need not know what
2558 HeKEY_hek(entry) = hek;
2559 entry->he_valu.hent_refcount = 0;
2560 HeNEXT(entry) = next;
2563 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2564 if (!next) { /* initial entry? */
2565 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2570 ++entry->he_valu.hent_refcount;
2572 if (flags & HVhek_FREEKEY)
2575 return HeKEY_hek(entry);
2579 Perl_hv_placeholders_p(pTHX_ HV *hv)
2582 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2584 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2587 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2590 Perl_die(aTHX_ "panic: hv_placeholders_p");
2593 return &(mg->mg_len);
2598 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2601 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2603 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2605 return mg ? mg->mg_len : 0;
2609 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2612 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2614 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2619 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2620 Perl_die(aTHX_ "panic: hv_placeholders_set");
2622 /* else we don't need to add magic to record 0 placeholders. */
2626 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2631 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2633 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2638 value = &PL_sv_placeholder;
2641 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2644 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2647 case HVrhek_PV_UTF8:
2648 /* Create a string SV that directly points to the bytes in our
2650 value = newSV_type(SVt_PV);
2651 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2652 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2653 /* This stops anything trying to free it */
2654 SvLEN_set(value, 0);
2656 SvREADONLY_on(value);
2657 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2661 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2662 he->refcounted_he_data[0]);
2668 =for apidoc refcounted_he_chain_2hv
2670 Generates and returns a C<HV *> by walking up the tree starting at the passed
2671 in C<struct refcounted_he *>.
2676 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2680 U32 placeholders = 0;
2681 /* We could chase the chain once to get an idea of the number of keys,
2682 and call ksplit. But for now we'll make a potentially inefficient
2683 hash with only 8 entries in its array. */
2684 const U32 max = HvMAX(hv);
2688 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2689 HvARRAY(hv) = (HE**)array;
2694 U32 hash = chain->refcounted_he_hash;
2696 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2698 HE **oentry = &((HvARRAY(hv))[hash & max]);
2699 HE *entry = *oentry;
2702 for (; entry; entry = HeNEXT(entry)) {
2703 if (HeHASH(entry) == hash) {
2704 /* We might have a duplicate key here. If so, entry is older
2705 than the key we've already put in the hash, so if they are
2706 the same, skip adding entry. */
2708 const STRLEN klen = HeKLEN(entry);
2709 const char *const key = HeKEY(entry);
2710 if (klen == chain->refcounted_he_keylen
2711 && (!!HeKUTF8(entry)
2712 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2713 && memEQ(key, REF_HE_KEY(chain), klen))
2716 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2718 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2719 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2720 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2731 = share_hek_flags(REF_HE_KEY(chain),
2732 chain->refcounted_he_keylen,
2733 chain->refcounted_he_hash,
2734 (chain->refcounted_he_data[0]
2735 & (HVhek_UTF8|HVhek_WASUTF8)));
2737 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2739 value = refcounted_he_value(chain);
2740 if (value == &PL_sv_placeholder)
2742 HeVAL(entry) = value;
2744 /* Link it into the chain. */
2745 HeNEXT(entry) = *oentry;
2751 chain = chain->refcounted_he_next;
2755 clear_placeholders(hv, placeholders);
2756 HvTOTALKEYS(hv) -= placeholders;
2759 /* We could check in the loop to see if we encounter any keys with key
2760 flags, but it's probably not worth it, as this per-hash flag is only
2761 really meant as an optimisation for things like Storable. */
2763 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2769 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2770 const char *key, STRLEN klen, int flags, U32 hash)
2773 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2774 of your key has to exactly match that which is stored. */
2775 SV *value = &PL_sv_placeholder;
2778 /* No point in doing any of this if there's nothing to find. */
2782 if (flags & HVhek_FREEKEY)
2784 key = SvPV_const(keysv, klen);
2786 is_utf8 = (SvUTF8(keysv) != 0);
2788 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2792 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2793 hash = SvSHARED_HASH(keysv);
2795 PERL_HASH(hash, key, klen);
2799 for (; chain; chain = chain->refcounted_he_next) {
2801 if (hash != chain->refcounted_he_hash)
2803 if (klen != chain->refcounted_he_keylen)
2805 if (memNE(REF_HE_KEY(chain),key,klen))
2807 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2810 if (hash != HEK_HASH(chain->refcounted_he_hek))
2812 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2814 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2816 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2820 value = sv_2mortal(refcounted_he_value(chain));
2825 if (flags & HVhek_FREEKEY)
2832 =for apidoc refcounted_he_new
2834 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2835 stored in a compact form, all references remain the property of the caller.
2836 The C<struct refcounted_he> is returned with a reference count of 1.
2841 struct refcounted_he *
2842 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2843 SV *const key, SV *const value) {
2846 const char *key_p = SvPV_const(key, key_len);
2847 STRLEN value_len = 0;
2848 const char *value_p = NULL;
2851 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2854 value_type = HVrhek_PV;
2855 } else if (SvIOK(value)) {
2856 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2857 } else if (value == &PL_sv_placeholder) {
2858 value_type = HVrhek_delete;
2859 } else if (!SvOK(value)) {
2860 value_type = HVrhek_undef;
2862 value_type = HVrhek_PV;
2865 if (value_type == HVrhek_PV) {
2866 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2867 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2868 value_p = SvPV_const(value, value_len);
2870 value_type = HVrhek_PV_UTF8;
2875 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2876 As we're going to be building hash keys from this value in future,
2877 normalise it now. */
2878 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2879 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2882 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2883 ((value_type == HVrhek_PV
2884 || value_type == HVrhek_PV_UTF8) ?
2885 (void *)value_p : (void *)value),
2889 static struct refcounted_he *
2890 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2891 const char *const key_p, const STRLEN key_len,
2892 const char flags, char value_type,
2893 const void *value, const STRLEN value_len) {
2895 struct refcounted_he *he;
2897 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2898 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2900 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2903 he = (struct refcounted_he*)
2904 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2908 he = (struct refcounted_he*)
2909 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2913 he->refcounted_he_next = parent;
2916 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2917 he->refcounted_he_val.refcounted_he_u_len = value_len;
2918 } else if (value_type == HVrhek_IV) {
2919 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2920 } else if (value_type == HVrhek_UV) {
2921 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2924 PERL_HASH(hash, key_p, key_len);
2927 he->refcounted_he_hash = hash;
2928 he->refcounted_he_keylen = key_len;
2929 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2931 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2934 if (flags & HVhek_WASUTF8) {
2935 /* If it was downgraded from UTF-8, then the pointer returned from
2936 bytes_from_utf8 is an allocated pointer that we must free. */
2940 he->refcounted_he_data[0] = flags;
2941 he->refcounted_he_refcnt = 1;
2947 =for apidoc refcounted_he_free
2949 Decrements the reference count of the passed in C<struct refcounted_he *>
2950 by one. If the reference count reaches zero the structure's memory is freed,
2951 and C<refcounted_he_free> iterates onto the parent node.
2957 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2959 PERL_UNUSED_CONTEXT;
2962 struct refcounted_he *copy;
2966 new_count = --he->refcounted_he_refcnt;
2967 HINTS_REFCNT_UNLOCK;
2973 #ifndef USE_ITHREADS
2974 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2977 he = he->refcounted_he_next;
2978 PerlMemShared_free(copy);
2982 /* pp_entereval is aware that labels are stored with a key ':' at the top of
2985 Perl_fetch_cop_label(pTHX_ struct refcounted_he *const chain, STRLEN *len,
2990 if (chain->refcounted_he_keylen != 1)
2992 if (*REF_HE_KEY(chain) != ':')
2995 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
2997 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3000 /* Stop anyone trying to really mess us up by adding their own value for
3002 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3003 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3007 *len = chain->refcounted_he_val.refcounted_he_u_len;
3009 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3010 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3012 return chain->refcounted_he_data + 1;
3015 /* As newSTATEOP currently gets passed plain char* labels, we will only provide
3016 that interface. Once it works out how to pass in length and UTF-8 ness, this
3017 function will need superseding. */
3018 struct refcounted_he *
3019 Perl_store_cop_label(pTHX_ struct refcounted_he *const chain, const char *label)
3021 PERL_ARGS_ASSERT_STORE_COP_LABEL;
3023 return refcounted_he_new_common(chain, ":", 1, HVrhek_PV, HVrhek_PV,
3024 label, strlen(label));
3028 =for apidoc hv_assert
3030 Check that a hash is in an internally consistent state.
3038 Perl_hv_assert(pTHX_ HV *hv)
3043 int placeholders = 0;
3046 const I32 riter = HvRITER_get(hv);
3047 HE *eiter = HvEITER_get(hv);
3049 PERL_ARGS_ASSERT_HV_ASSERT;
3051 (void)hv_iterinit(hv);
3053 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3054 /* sanity check the values */
3055 if (HeVAL(entry) == &PL_sv_placeholder)
3059 /* sanity check the keys */
3060 if (HeSVKEY(entry)) {
3061 NOOP; /* Don't know what to check on SV keys. */
3062 } else if (HeKUTF8(entry)) {
3064 if (HeKWASUTF8(entry)) {
3065 PerlIO_printf(Perl_debug_log,
3066 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3067 (int) HeKLEN(entry), HeKEY(entry));
3070 } else if (HeKWASUTF8(entry))
3073 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3074 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3075 const int nhashkeys = HvUSEDKEYS(hv);
3076 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3078 if (nhashkeys != real) {
3079 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3082 if (nhashplaceholders != placeholders) {
3083 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3087 if (withflags && ! HvHASKFLAGS(hv)) {
3088 PerlIO_printf(Perl_debug_log,
3089 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3094 sv_dump(MUTABLE_SV(hv));
3096 HvRITER_set(hv, riter); /* Restore hash iterator state */
3097 HvEITER_set(hv, eiter);
3104 * c-indentation-style: bsd
3106 * indent-tabs-mode: t
3109 * ex: set ts=8 sts=4 sw=4 noet: