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";
45 #define new_HE() (HE*)safemalloc(sizeof(HE))
46 #define del_HE(p) safefree((char*)p)
55 void ** const root = &PL_body_roots[HE_SVSLOT];
58 Perl_more_bodies(aTHX_ HE_SVSLOT, sizeof(HE), PERL_ARENA_SIZE);
65 #define new_HE() new_he()
68 HeNEXT(p) = (HE*)(PL_body_roots[HE_SVSLOT]); \
69 PL_body_roots[HE_SVSLOT] = p; \
77 S_save_hek_flags(const char *str, I32 len, U32 hash, int flags)
79 const int flags_masked = flags & HVhek_MASK;
83 PERL_ARGS_ASSERT_SAVE_HEK_FLAGS;
85 Newx(k, HEK_BASESIZE + len + 2, char);
87 Copy(str, HEK_KEY(hek), len, char);
88 HEK_KEY(hek)[len] = 0;
91 HEK_FLAGS(hek) = (unsigned char)flags_masked | HVhek_UNSHARED;
93 if (flags & HVhek_FREEKEY)
98 /* free the pool of temporary HE/HEK pairs returned by hv_fetch_ent
102 Perl_free_tied_hv_pool(pTHX)
105 HE *he = PL_hv_fetch_ent_mh;
108 Safefree(HeKEY_hek(he));
112 PL_hv_fetch_ent_mh = NULL;
115 #if defined(USE_ITHREADS)
117 Perl_hek_dup(pTHX_ HEK *source, CLONE_PARAMS* param)
121 PERL_ARGS_ASSERT_HEK_DUP;
122 PERL_UNUSED_ARG(param);
127 shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
129 /* We already shared this hash key. */
130 (void)share_hek_hek(shared);
134 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
135 HEK_HASH(source), HEK_FLAGS(source));
136 ptr_table_store(PL_ptr_table, source, shared);
142 Perl_he_dup(pTHX_ const HE *e, bool shared, CLONE_PARAMS* param)
146 PERL_ARGS_ASSERT_HE_DUP;
150 /* look for it in the table first */
151 ret = (HE*)ptr_table_fetch(PL_ptr_table, e);
155 /* create anew and remember what it is */
157 ptr_table_store(PL_ptr_table, e, ret);
159 HeNEXT(ret) = he_dup(HeNEXT(e),shared, param);
160 if (HeKLEN(e) == HEf_SVKEY) {
162 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
163 HeKEY_hek(ret) = (HEK*)k;
164 HeKEY_sv(ret) = sv_dup_inc(HeKEY_sv(e), param);
167 /* This is hek_dup inlined, which seems to be important for speed
169 HEK * const source = HeKEY_hek(e);
170 HEK *shared = (HEK*)ptr_table_fetch(PL_ptr_table, source);
173 /* We already shared this hash key. */
174 (void)share_hek_hek(shared);
178 = share_hek_flags(HEK_KEY(source), HEK_LEN(source),
179 HEK_HASH(source), HEK_FLAGS(source));
180 ptr_table_store(PL_ptr_table, source, shared);
182 HeKEY_hek(ret) = shared;
185 HeKEY_hek(ret) = save_hek_flags(HeKEY(e), HeKLEN(e), HeHASH(e),
187 HeVAL(ret) = sv_dup_inc(HeVAL(e), param);
190 #endif /* USE_ITHREADS */
193 S_hv_notallowed(pTHX_ int flags, const char *key, I32 klen,
196 SV * const sv = sv_newmortal();
198 PERL_ARGS_ASSERT_HV_NOTALLOWED;
200 if (!(flags & HVhek_FREEKEY)) {
201 sv_setpvn(sv, key, klen);
204 /* Need to free saved eventually assign to mortal SV */
205 /* XXX is this line an error ???: SV *sv = sv_newmortal(); */
206 sv_usepvn(sv, (char *) key, klen);
208 if (flags & HVhek_UTF8) {
211 Perl_croak(aTHX_ msg, SVfARG(sv));
214 /* (klen == HEf_SVKEY) is special for MAGICAL hv entries, meaning key slot
220 Stores an SV in a hash. The hash key is specified as C<key> and C<klen> is
221 the length of the key. The C<hash> parameter is the precomputed hash
222 value; if it is zero then Perl will compute it. The return value will be
223 NULL if the operation failed or if the value did not need to be actually
224 stored within the hash (as in the case of tied hashes). Otherwise it can
225 be dereferenced to get the original C<SV*>. Note that the caller is
226 responsible for suitably incrementing the reference count of C<val> before
227 the call, and decrementing it if the function returned NULL. Effectively
228 a successful hv_store takes ownership of one reference to C<val>. This is
229 usually what you want; a newly created SV has a reference count of one, so
230 if all your code does is create SVs then store them in a hash, hv_store
231 will own the only reference to the new SV, and your code doesn't need to do
232 anything further to tidy up. hv_store is not implemented as a call to
233 hv_store_ent, and does not create a temporary SV for the key, so if your
234 key data is not already in SV form then use hv_store in preference to
237 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
238 information on how to use this function on tied hashes.
240 =for apidoc hv_store_ent
242 Stores C<val> in a hash. The hash key is specified as C<key>. The C<hash>
243 parameter is the precomputed hash value; if it is zero then Perl will
244 compute it. The return value is the new hash entry so created. It will be
245 NULL if the operation failed or if the value did not need to be actually
246 stored within the hash (as in the case of tied hashes). Otherwise the
247 contents of the return value can be accessed using the C<He?> macros
248 described here. Note that the caller is responsible for suitably
249 incrementing the reference count of C<val> before the call, and
250 decrementing it if the function returned NULL. Effectively a successful
251 hv_store_ent takes ownership of one reference to C<val>. This is
252 usually what you want; a newly created SV has a reference count of one, so
253 if all your code does is create SVs then store them in a hash, hv_store
254 will own the only reference to the new SV, and your code doesn't need to do
255 anything further to tidy up. Note that hv_store_ent only reads the C<key>;
256 unlike C<val> it does not take ownership of it, so maintaining the correct
257 reference count on C<key> is entirely the caller's responsibility. hv_store
258 is not implemented as a call to hv_store_ent, and does not create a temporary
259 SV for the key, so if your key data is not already in SV form then use
260 hv_store in preference to hv_store_ent.
262 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
263 information on how to use this function on tied hashes.
265 =for apidoc hv_exists
267 Returns a boolean indicating whether the specified hash key exists. The
268 C<klen> is the length of the key.
272 Returns the SV which corresponds to the specified key in the hash. The
273 C<klen> is the length of the key. If C<lval> is set then the fetch will be
274 part of a store. Check that the return value is non-null before
275 dereferencing it to an C<SV*>.
277 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
278 information on how to use this function on tied hashes.
280 =for apidoc hv_exists_ent
282 Returns a boolean indicating whether the specified hash key exists. C<hash>
283 can be a valid precomputed hash value, or 0 to ask for it to be
289 /* returns an HE * structure with the all fields set */
290 /* note that hent_val will be a mortal sv for MAGICAL hashes */
292 =for apidoc hv_fetch_ent
294 Returns the hash entry which corresponds to the specified key in the hash.
295 C<hash> must be a valid precomputed hash number for the given C<key>, or 0
296 if you want the function to compute it. IF C<lval> is set then the fetch
297 will be part of a store. Make sure the return value is non-null before
298 accessing it. The return value when C<hv> is a tied hash is a pointer to a
299 static location, so be sure to make a copy of the structure if you need to
302 See L<perlguts/"Understanding the Magic of Tied Hashes and Arrays"> for more
303 information on how to use this function on tied hashes.
308 /* Common code for hv_delete()/hv_exists()/hv_fetch()/hv_store() */
310 Perl_hv_common_key_len(pTHX_ HV *hv, const char *key, I32 klen_i32,
311 const int action, SV *val, const U32 hash)
316 PERL_ARGS_ASSERT_HV_COMMON_KEY_LEN;
325 return hv_common(hv, NULL, key, klen, flags, action, val, hash);
329 Perl_hv_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
330 int flags, int action, SV *val, register U32 hash)
339 const int return_svp = action & HV_FETCH_JUST_SV;
343 if (SvTYPE(hv) == SVTYPEMASK)
346 assert(SvTYPE(hv) == SVt_PVHV);
348 if (SvSMAGICAL(hv) && SvGMAGICAL(hv) && !(action & HV_DISABLE_UVAR_XKEY)) {
350 if ((mg = mg_find((const SV *)hv, PERL_MAGIC_uvar))) {
351 struct ufuncs * const uf = (struct ufuncs *)mg->mg_ptr;
352 if (uf->uf_set == NULL) {
353 SV* obj = mg->mg_obj;
356 keysv = newSVpvn_flags(key, klen, SVs_TEMP |
357 ((flags & HVhek_UTF8)
361 mg->mg_obj = keysv; /* pass key */
362 uf->uf_index = action; /* pass action */
363 magic_getuvar(MUTABLE_SV(hv), mg);
364 keysv = mg->mg_obj; /* may have changed */
367 /* If the key may have changed, then we need to invalidate
368 any passed-in computed hash value. */
374 if (flags & HVhek_FREEKEY)
376 key = SvPV_const(keysv, klen);
377 is_utf8 = (SvUTF8(keysv) != 0);
378 if (SvIsCOW_shared_hash(keysv)) {
379 flags = HVhek_KEYCANONICAL | (is_utf8 ? HVhek_UTF8 : 0);
384 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
387 if (action & HV_DELETE) {
388 return (void *) hv_delete_common(hv, keysv, key, klen,
389 flags | (is_utf8 ? HVhek_UTF8 : 0),
393 xhv = (XPVHV*)SvANY(hv);
395 if (SvRMAGICAL(hv) && !(action & (HV_FETCH_ISSTORE|HV_FETCH_ISEXISTS))) {
396 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
397 || SvGMAGICAL((const SV *)hv))
399 /* FIXME should be able to skimp on the HE/HEK here when
400 HV_FETCH_JUST_SV is true. */
402 keysv = newSVpvn_utf8(key, klen, is_utf8);
404 keysv = newSVsv(keysv);
407 mg_copy(MUTABLE_SV(hv), sv, (char *)keysv, HEf_SVKEY);
409 /* grab a fake HE/HEK pair from the pool or make a new one */
410 entry = PL_hv_fetch_ent_mh;
412 PL_hv_fetch_ent_mh = HeNEXT(entry);
416 Newx(k, HEK_BASESIZE + sizeof(const SV *), char);
417 HeKEY_hek(entry) = (HEK*)k;
419 HeNEXT(entry) = NULL;
420 HeSVKEY_set(entry, keysv);
422 sv_upgrade(sv, SVt_PVLV);
424 /* so we can free entry when freeing sv */
425 LvTARG(sv) = MUTABLE_SV(entry);
427 /* XXX remove at some point? */
428 if (flags & HVhek_FREEKEY)
432 return entry ? (void *) &HeVAL(entry) : NULL;
434 return (void *) entry;
436 #ifdef ENV_IS_CASELESS
437 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
439 for (i = 0; i < klen; ++i)
440 if (isLOWER(key[i])) {
441 /* Would be nice if we had a routine to do the
442 copy and upercase in a single pass through. */
443 const char * const nkey = strupr(savepvn(key,klen));
444 /* Note that this fetch is for nkey (the uppercased
445 key) whereas the store is for key (the original) */
446 void *result = hv_common(hv, NULL, nkey, klen,
447 HVhek_FREEKEY, /* free nkey */
448 0 /* non-LVAL fetch */
449 | HV_DISABLE_UVAR_XKEY
452 0 /* compute hash */);
453 if (!result && (action & HV_FETCH_LVALUE)) {
454 /* This call will free key if necessary.
455 Do it this way to encourage compiler to tail
457 result = hv_common(hv, keysv, key, klen, flags,
459 | HV_DISABLE_UVAR_XKEY
463 if (flags & HVhek_FREEKEY)
471 else if (SvRMAGICAL(hv) && (action & HV_FETCH_ISEXISTS)) {
472 if (mg_find((const SV *)hv, PERL_MAGIC_tied)
473 || SvGMAGICAL((const SV *)hv)) {
474 /* I don't understand why hv_exists_ent has svret and sv,
475 whereas hv_exists only had one. */
476 SV * const svret = sv_newmortal();
479 if (keysv || is_utf8) {
481 keysv = newSVpvn_utf8(key, klen, TRUE);
483 keysv = newSVsv(keysv);
485 mg_copy(MUTABLE_SV(hv), sv, (char *)sv_2mortal(keysv), HEf_SVKEY);
487 mg_copy(MUTABLE_SV(hv), sv, key, klen);
489 if (flags & HVhek_FREEKEY)
491 magic_existspack(svret, mg_find(sv, PERL_MAGIC_tiedelem));
492 /* This cast somewhat evil, but I'm merely using NULL/
493 not NULL to return the boolean exists.
494 And I know hv is not NULL. */
495 return SvTRUE(svret) ? (void *)hv : NULL;
497 #ifdef ENV_IS_CASELESS
498 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
499 /* XXX This code isn't UTF8 clean. */
500 char * const keysave = (char * const)key;
501 /* Will need to free this, so set FREEKEY flag. */
502 key = savepvn(key,klen);
503 key = (const char*)strupr((char*)key);
508 if (flags & HVhek_FREEKEY) {
511 flags |= HVhek_FREEKEY;
515 else if (action & HV_FETCH_ISSTORE) {
518 hv_magic_check (hv, &needs_copy, &needs_store);
520 const bool save_taint = PL_tainted;
521 if (keysv || is_utf8) {
523 keysv = newSVpvn_utf8(key, klen, TRUE);
526 PL_tainted = SvTAINTED(keysv);
527 keysv = sv_2mortal(newSVsv(keysv));
528 mg_copy(MUTABLE_SV(hv), val, (char*)keysv, HEf_SVKEY);
530 mg_copy(MUTABLE_SV(hv), val, key, klen);
533 TAINT_IF(save_taint);
535 if (flags & HVhek_FREEKEY)
539 #ifdef ENV_IS_CASELESS
540 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
541 /* XXX This code isn't UTF8 clean. */
542 const char *keysave = key;
543 /* Will need to free this, so set FREEKEY flag. */
544 key = savepvn(key,klen);
545 key = (const char*)strupr((char*)key);
550 if (flags & HVhek_FREEKEY) {
553 flags |= HVhek_FREEKEY;
561 if ((action & (HV_FETCH_LVALUE | HV_FETCH_ISSTORE))
562 #ifdef DYNAMIC_ENV_FETCH /* if it's an %ENV lookup, we may get it on the fly */
563 || (SvRMAGICAL((const SV *)hv)
564 && mg_find((const SV *)hv, PERL_MAGIC_env))
569 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
571 HvARRAY(hv) = (HE**)array;
573 #ifdef DYNAMIC_ENV_FETCH
574 else if (action & HV_FETCH_ISEXISTS) {
575 /* for an %ENV exists, if we do an insert it's by a recursive
576 store call, so avoid creating HvARRAY(hv) right now. */
580 /* XXX remove at some point? */
581 if (flags & HVhek_FREEKEY)
588 if (is_utf8 & !(flags & HVhek_KEYCANONICAL)) {
589 char * const keysave = (char *)key;
590 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
594 flags &= ~HVhek_UTF8;
595 if (key != keysave) {
596 if (flags & HVhek_FREEKEY)
598 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
599 /* If the caller calculated a hash, it was on the sequence of
600 octets that are the UTF-8 form. We've now changed the sequence
601 of octets stored to that of the equivalent byte representation,
602 so the hash we need is different. */
608 PERL_HASH_INTERNAL(hash, key, klen);
609 /* We don't have a pointer to the hv, so we have to replicate the
610 flag into every HEK, so that hv_iterkeysv can see it. */
611 /* And yes, you do need this even though you are not "storing" because
612 you can flip the flags below if doing an lval lookup. (And that
613 was put in to give the semantics Andreas was expecting.) */
614 flags |= HVhek_REHASH;
616 if (keysv && (SvIsCOW_shared_hash(keysv))) {
617 hash = SvSHARED_HASH(keysv);
619 PERL_HASH(hash, key, klen);
623 masked_flags = (flags & HVhek_MASK);
625 #ifdef DYNAMIC_ENV_FETCH
626 if (!HvARRAY(hv)) entry = NULL;
630 entry = (HvARRAY(hv))[hash & (I32) HvMAX(hv)];
632 for (; entry; entry = HeNEXT(entry)) {
633 if (HeHASH(entry) != hash) /* strings can't be equal */
635 if (HeKLEN(entry) != (I32)klen)
637 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
639 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
642 if (action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE)) {
643 if (HeKFLAGS(entry) != masked_flags) {
644 /* We match if HVhek_UTF8 bit in our flags and hash key's
645 match. But if entry was set previously with HVhek_WASUTF8
646 and key now doesn't (or vice versa) then we should change
647 the key's flag, as this is assignment. */
648 if (HvSHAREKEYS(hv)) {
649 /* Need to swap the key we have for a key with the flags we
650 need. As keys are shared we can't just write to the
651 flag, so we share the new one, unshare the old one. */
652 HEK * const new_hek = share_hek_flags(key, klen, hash,
654 unshare_hek (HeKEY_hek(entry));
655 HeKEY_hek(entry) = new_hek;
657 else if (hv == PL_strtab) {
658 /* PL_strtab is usually the only hash without HvSHAREKEYS,
659 so putting this test here is cheap */
660 if (flags & HVhek_FREEKEY)
662 Perl_croak(aTHX_ S_strtab_error,
663 action & HV_FETCH_LVALUE ? "fetch" : "store");
666 HeKFLAGS(entry) = masked_flags;
667 if (masked_flags & HVhek_ENABLEHVKFLAGS)
670 if (HeVAL(entry) == &PL_sv_placeholder) {
671 /* yes, can store into placeholder slot */
672 if (action & HV_FETCH_LVALUE) {
674 /* This preserves behaviour with the old hv_fetch
675 implementation which at this point would bail out
676 with a break; (at "if we find a placeholder, we
677 pretend we haven't found anything")
679 That break mean that if a placeholder were found, it
680 caused a call into hv_store, which in turn would
681 check magic, and if there is no magic end up pretty
682 much back at this point (in hv_store's code). */
685 /* LVAL fetch which actaully needs a store. */
687 HvPLACEHOLDERS(hv)--;
690 if (val != &PL_sv_placeholder)
691 HvPLACEHOLDERS(hv)--;
694 } else if (action & HV_FETCH_ISSTORE) {
695 SvREFCNT_dec(HeVAL(entry));
698 } else if (HeVAL(entry) == &PL_sv_placeholder) {
699 /* if we find a placeholder, we pretend we haven't found
703 if (flags & HVhek_FREEKEY)
706 return entry ? (void *) &HeVAL(entry) : NULL;
710 #ifdef DYNAMIC_ENV_FETCH /* %ENV lookup? If so, try to fetch the value now */
711 if (!(action & HV_FETCH_ISSTORE)
712 && SvRMAGICAL((const SV *)hv)
713 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
715 const char * const env = PerlEnv_ENVgetenv_len(key,&len);
717 sv = newSVpvn(env,len);
719 return hv_common(hv, keysv, key, klen, flags,
720 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
726 if (!entry && SvREADONLY(hv) && !(action & HV_FETCH_ISEXISTS)) {
727 hv_notallowed(flags, key, klen,
728 "Attempt to access disallowed key '%"SVf"' in"
729 " a restricted hash");
731 if (!(action & (HV_FETCH_LVALUE|HV_FETCH_ISSTORE))) {
732 /* Not doing some form of store, so return failure. */
733 if (flags & HVhek_FREEKEY)
737 if (action & HV_FETCH_LVALUE) {
740 /* At this point the old hv_fetch code would call to hv_store,
741 which in turn might do some tied magic. So we need to make that
742 magic check happen. */
743 /* gonna assign to this, so it better be there */
744 /* If a fetch-as-store fails on the fetch, then the action is to
745 recurse once into "hv_store". If we didn't do this, then that
746 recursive call would call the key conversion routine again.
747 However, as we replace the original key with the converted
748 key, this would result in a double conversion, which would show
749 up as a bug if the conversion routine is not idempotent. */
750 return hv_common(hv, keysv, key, klen, flags,
751 HV_FETCH_ISSTORE|HV_DISABLE_UVAR_XKEY|return_svp,
753 /* XXX Surely that could leak if the fetch-was-store fails?
754 Just like the hv_fetch. */
758 /* Welcome to hv_store... */
761 /* Not sure if we can get here. I think the only case of oentry being
762 NULL is for %ENV with dynamic env fetch. But that should disappear
763 with magic in the previous code. */
766 PERL_HV_ARRAY_ALLOC_BYTES(xhv->xhv_max+1 /* HvMAX(hv)+1 */),
768 HvARRAY(hv) = (HE**)array;
771 oentry = &(HvARRAY(hv))[hash & (I32) xhv->xhv_max];
774 /* share_hek_flags will do the free for us. This might be considered
777 HeKEY_hek(entry) = share_hek_flags(key, klen, hash, flags);
778 else if (hv == PL_strtab) {
779 /* PL_strtab is usually the only hash without HvSHAREKEYS, so putting
780 this test here is cheap */
781 if (flags & HVhek_FREEKEY)
783 Perl_croak(aTHX_ S_strtab_error,
784 action & HV_FETCH_LVALUE ? "fetch" : "store");
786 else /* gotta do the real thing */
787 HeKEY_hek(entry) = save_hek_flags(key, klen, hash, flags);
789 HeNEXT(entry) = *oentry;
792 if (val == &PL_sv_placeholder)
793 HvPLACEHOLDERS(hv)++;
794 if (masked_flags & HVhek_ENABLEHVKFLAGS)
798 const HE *counter = HeNEXT(entry);
800 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
801 if (!counter) { /* initial entry? */
802 } else if (xhv->xhv_keys > xhv->xhv_max) {
804 } else if(!HvREHASH(hv)) {
807 while ((counter = HeNEXT(counter)))
810 if (n_links > HV_MAX_LENGTH_BEFORE_SPLIT) {
811 /* Use only the old HvKEYS(hv) > HvMAX(hv) condition to limit
812 bucket splits on a rehashed hash, as we're not going to
813 split it again, and if someone is lucky (evil) enough to
814 get all the keys in one list they could exhaust our memory
815 as we repeatedly double the number of buckets on every
816 entry. Linear search feels a less worse thing to do. */
823 return entry ? (void *) &HeVAL(entry) : NULL;
825 return (void *) entry;
829 S_hv_magic_check(HV *hv, bool *needs_copy, bool *needs_store)
831 const MAGIC *mg = SvMAGIC(hv);
833 PERL_ARGS_ASSERT_HV_MAGIC_CHECK;
838 if (isUPPER(mg->mg_type)) {
840 if (mg->mg_type == PERL_MAGIC_tied) {
841 *needs_store = FALSE;
842 return; /* We've set all there is to set. */
845 mg = mg->mg_moremagic;
850 =for apidoc hv_scalar
852 Evaluates the hash in scalar context and returns the result. Handles magic when the hash is tied.
858 Perl_hv_scalar(pTHX_ HV *hv)
862 PERL_ARGS_ASSERT_HV_SCALAR;
864 if (SvRMAGICAL(hv)) {
865 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_tied);
867 return magic_scalarpack(hv, mg);
871 if (HvTOTALKEYS((const HV *)hv))
872 Perl_sv_setpvf(aTHX_ sv, "%ld/%ld",
873 (long)HvFILL(hv), (long)HvMAX(hv) + 1);
881 =for apidoc hv_delete
883 Deletes a key/value pair in the hash. The value SV is removed from the
884 hash and returned to the caller. The C<klen> is the length of the key.
885 The C<flags> value will normally be zero; if set to G_DISCARD then NULL
888 =for apidoc hv_delete_ent
890 Deletes a key/value pair in the hash. The value SV is removed from the
891 hash and returned to the caller. The C<flags> value will normally be zero;
892 if set to G_DISCARD then NULL will be returned. C<hash> can be a valid
893 precomputed hash value, or 0 to ask for it to be computed.
899 S_hv_delete_common(pTHX_ HV *hv, SV *keysv, const char *key, STRLEN klen,
900 int k_flags, I32 d_flags, U32 hash)
905 register HE **oentry;
906 HE *const *first_entry;
907 bool is_utf8 = (k_flags & HVhek_UTF8) ? TRUE : FALSE;
910 if (SvRMAGICAL(hv)) {
913 hv_magic_check (hv, &needs_copy, &needs_store);
917 entry = (HE *) hv_common(hv, keysv, key, klen,
918 k_flags & ~HVhek_FREEKEY,
919 HV_FETCH_LVALUE|HV_DISABLE_UVAR_XKEY,
921 sv = entry ? HeVAL(entry) : NULL;
927 if (mg_find(sv, PERL_MAGIC_tiedelem)) {
928 /* No longer an element */
929 sv_unmagic(sv, PERL_MAGIC_tiedelem);
932 return NULL; /* element cannot be deleted */
934 #ifdef ENV_IS_CASELESS
935 else if (mg_find((const SV *)hv, PERL_MAGIC_env)) {
936 /* XXX This code isn't UTF8 clean. */
937 keysv = newSVpvn_flags(key, klen, SVs_TEMP);
938 if (k_flags & HVhek_FREEKEY) {
941 key = strupr(SvPVX(keysv));
950 xhv = (XPVHV*)SvANY(hv);
955 const char * const keysave = key;
956 key = (char*)bytes_from_utf8((U8*)key, &klen, &is_utf8);
959 k_flags |= HVhek_UTF8;
961 k_flags &= ~HVhek_UTF8;
962 if (key != keysave) {
963 if (k_flags & HVhek_FREEKEY) {
964 /* This shouldn't happen if our caller does what we expect,
965 but strictly the API allows it. */
968 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
970 HvHASKFLAGS_on(MUTABLE_SV(hv));
974 PERL_HASH_INTERNAL(hash, key, klen);
976 if (keysv && (SvIsCOW_shared_hash(keysv))) {
977 hash = SvSHARED_HASH(keysv);
979 PERL_HASH(hash, key, klen);
983 masked_flags = (k_flags & HVhek_MASK);
985 first_entry = oentry = &(HvARRAY(hv))[hash & (I32) HvMAX(hv)];
987 for (; entry; oentry = &HeNEXT(entry), entry = *oentry) {
989 if (HeHASH(entry) != hash) /* strings can't be equal */
991 if (HeKLEN(entry) != (I32)klen)
993 if (HeKEY(entry) != key && memNE(HeKEY(entry),key,klen)) /* is this it? */
995 if ((HeKFLAGS(entry) ^ masked_flags) & HVhek_UTF8)
998 if (hv == PL_strtab) {
999 if (k_flags & HVhek_FREEKEY)
1001 Perl_croak(aTHX_ S_strtab_error, "delete");
1004 /* if placeholder is here, it's already been deleted.... */
1005 if (HeVAL(entry) == &PL_sv_placeholder) {
1006 if (k_flags & HVhek_FREEKEY)
1010 if (SvREADONLY(hv) && HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1011 hv_notallowed(k_flags, key, klen,
1012 "Attempt to delete readonly key '%"SVf"' from"
1013 " a restricted hash");
1015 if (k_flags & HVhek_FREEKEY)
1018 if (d_flags & G_DISCARD)
1021 sv = sv_2mortal(HeVAL(entry));
1022 HeVAL(entry) = &PL_sv_placeholder;
1026 * If a restricted hash, rather than really deleting the entry, put
1027 * a placeholder there. This marks the key as being "approved", so
1028 * we can still access via not-really-existing key without raising
1031 if (SvREADONLY(hv)) {
1032 SvREFCNT_dec(HeVAL(entry));
1033 HeVAL(entry) = &PL_sv_placeholder;
1034 /* We'll be saving this slot, so the number of allocated keys
1035 * doesn't go down, but the number placeholders goes up */
1036 HvPLACEHOLDERS(hv)++;
1038 *oentry = HeNEXT(entry);
1039 if (SvOOK(hv) && entry == HvAUX(hv)->xhv_eiter /* HvEITER(hv) */)
1042 hv_free_ent(hv, entry);
1043 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
1044 if (xhv->xhv_keys == 0)
1045 HvHASKFLAGS_off(hv);
1049 if (SvREADONLY(hv)) {
1050 hv_notallowed(k_flags, key, klen,
1051 "Attempt to delete disallowed key '%"SVf"' from"
1052 " a restricted hash");
1055 if (k_flags & HVhek_FREEKEY)
1061 S_hsplit(pTHX_ HV *hv)
1064 register XPVHV* const xhv = (XPVHV*)SvANY(hv);
1065 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1066 register I32 newsize = oldsize * 2;
1068 char *a = (char*) HvARRAY(hv);
1070 int longest_chain = 0;
1073 PERL_ARGS_ASSERT_HSPLIT;
1075 /*PerlIO_printf(PerlIO_stderr(), "hsplit called for %p which had %d\n",
1076 (void*)hv, (int) oldsize);*/
1078 if (HvPLACEHOLDERS_get(hv) && !SvREADONLY(hv)) {
1079 /* Can make this clear any placeholders first for non-restricted hashes,
1080 even though Storable rebuilds restricted hashes by putting in all the
1081 placeholders (first) before turning on the readonly flag, because
1082 Storable always pre-splits the hash. */
1083 hv_clear_placeholders(hv);
1087 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1088 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1089 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1095 Move(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1098 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1099 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1104 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1106 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1108 Safefree(HvARRAY(hv));
1112 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1113 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1114 HvARRAY(hv) = (HE**) a;
1117 for (i=0; i<oldsize; i++,aep++) {
1118 int left_length = 0;
1119 int right_length = 0;
1124 if (!entry) /* non-existent */
1128 if ((HeHASH(entry) & newsize) != (U32)i) {
1129 *oentry = HeNEXT(entry);
1130 HeNEXT(entry) = *bep;
1135 oentry = &HeNEXT(entry);
1140 /* I think we don't actually need to keep track of the longest length,
1141 merely flag if anything is too long. But for the moment while
1142 developing this code I'll track it. */
1143 if (left_length > longest_chain)
1144 longest_chain = left_length;
1145 if (right_length > longest_chain)
1146 longest_chain = right_length;
1150 /* Pick your policy for "hashing isn't working" here: */
1151 if (longest_chain <= HV_MAX_LENGTH_BEFORE_SPLIT /* split worked? */
1156 if (hv == PL_strtab) {
1157 /* Urg. Someone is doing something nasty to the string table.
1162 /* Awooga. Awooga. Pathological data. */
1163 /*PerlIO_printf(PerlIO_stderr(), "%p %d of %d with %d/%d buckets\n", (void*)hv,
1164 longest_chain, HvTOTALKEYS(hv), HvFILL(hv), 1+HvMAX(hv));*/
1167 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1168 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1170 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1173 was_shared = HvSHAREKEYS(hv);
1175 HvSHAREKEYS_off(hv);
1180 for (i=0; i<newsize; i++,aep++) {
1181 register HE *entry = *aep;
1183 /* We're going to trash this HE's next pointer when we chain it
1184 into the new hash below, so store where we go next. */
1185 HE * const next = HeNEXT(entry);
1190 PERL_HASH_INTERNAL(hash, HeKEY(entry), HeKLEN(entry));
1195 = save_hek_flags(HeKEY(entry), HeKLEN(entry),
1196 hash, HeKFLAGS(entry));
1197 unshare_hek (HeKEY_hek(entry));
1198 HeKEY_hek(entry) = new_hek;
1200 /* Not shared, so simply write the new hash in. */
1201 HeHASH(entry) = hash;
1203 /*PerlIO_printf(PerlIO_stderr(), "%d ", HeKFLAGS(entry));*/
1204 HEK_REHASH_on(HeKEY_hek(entry));
1205 /*PerlIO_printf(PerlIO_stderr(), "%d\n", HeKFLAGS(entry));*/
1207 /* Copy oentry to the correct new chain. */
1208 bep = ((HE**)a) + (hash & (I32) xhv->xhv_max);
1209 HeNEXT(entry) = *bep;
1215 Safefree (HvARRAY(hv));
1216 HvARRAY(hv) = (HE **)a;
1220 Perl_hv_ksplit(pTHX_ HV *hv, IV newmax)
1223 register XPVHV* xhv = (XPVHV*)SvANY(hv);
1224 const I32 oldsize = (I32) xhv->xhv_max+1; /* HvMAX(hv)+1 (sick) */
1225 register I32 newsize;
1230 PERL_ARGS_ASSERT_HV_KSPLIT;
1232 newsize = (I32) newmax; /* possible truncation here */
1233 if (newsize != newmax || newmax <= oldsize)
1235 while ((newsize & (1 + ~newsize)) != newsize) {
1236 newsize &= ~(newsize & (1 + ~newsize)); /* get proper power of 2 */
1238 if (newsize < newmax)
1240 if (newsize < newmax)
1241 return; /* overflow detection */
1243 a = (char *) HvARRAY(hv);
1246 #if defined(STRANGE_MALLOC) || defined(MYMALLOC)
1247 Renew(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1248 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1254 Copy(&a[oldsize * sizeof(HE*)], &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1257 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize)
1258 + (SvOOK(hv) ? sizeof(struct xpvhv_aux) : 0), char);
1263 Copy(HvARRAY(hv), a, oldsize * sizeof(HE*), char);
1265 Copy(HvAUX(hv), &a[newsize * sizeof(HE*)], 1, struct xpvhv_aux);
1267 Safefree(HvARRAY(hv));
1270 Zero(&a[oldsize * sizeof(HE*)], (newsize-oldsize) * sizeof(HE*), char); /* zero 2nd half*/
1273 Newxz(a, PERL_HV_ARRAY_ALLOC_BYTES(newsize), char);
1275 xhv->xhv_max = --newsize; /* HvMAX(hv) = --newsize */
1276 HvARRAY(hv) = (HE **) a;
1277 if (!xhv->xhv_keys /* !HvTOTALKEYS(hv) */) /* skip rest if no entries */
1281 for (i=0; i<oldsize; i++,aep++) {
1285 if (!entry) /* non-existent */
1288 register I32 j = (HeHASH(entry) & newsize);
1292 *oentry = HeNEXT(entry);
1293 HeNEXT(entry) = aep[j];
1297 oentry = &HeNEXT(entry);
1304 Perl_newHVhv(pTHX_ HV *ohv)
1307 HV * const hv = newHV();
1310 if (!ohv || !HvTOTALKEYS(ohv))
1312 hv_max = HvMAX(ohv);
1314 if (!SvMAGICAL((const SV *)ohv)) {
1315 /* It's an ordinary hash, so copy it fast. AMS 20010804 */
1317 const bool shared = !!HvSHAREKEYS(ohv);
1318 HE **ents, ** const oents = (HE **)HvARRAY(ohv);
1320 Newx(a, PERL_HV_ARRAY_ALLOC_BYTES(hv_max+1), char);
1323 /* In each bucket... */
1324 for (i = 0; i <= hv_max; i++) {
1326 HE *oent = oents[i];
1333 /* Copy the linked list of entries. */
1334 for (; oent; oent = HeNEXT(oent)) {
1335 const U32 hash = HeHASH(oent);
1336 const char * const key = HeKEY(oent);
1337 const STRLEN len = HeKLEN(oent);
1338 const int flags = HeKFLAGS(oent);
1339 HE * const ent = new_HE();
1340 SV *const val = HeVAL(oent);
1342 HeVAL(ent) = SvIMMORTAL(val) ? val : newSVsv(val);
1344 = shared ? share_hek_flags(key, len, hash, flags)
1345 : save_hek_flags(key, len, hash, flags);
1356 HvTOTALKEYS(hv) = HvTOTALKEYS(ohv);
1360 /* Iterate over ohv, copying keys and values one at a time. */
1362 const I32 riter = HvRITER_get(ohv);
1363 HE * const eiter = HvEITER_get(ohv);
1364 STRLEN hv_fill = HvFILL(ohv);
1366 /* Can we use fewer buckets? (hv_max is always 2^n-1) */
1367 while (hv_max && hv_max + 1 >= hv_fill * 2)
1368 hv_max = hv_max / 2;
1372 while ((entry = hv_iternext_flags(ohv, 0))) {
1373 SV *const val = HeVAL(entry);
1374 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1375 SvIMMORTAL(val) ? val : newSVsv(val),
1376 HeHASH(entry), HeKFLAGS(entry));
1378 HvRITER_set(ohv, riter);
1379 HvEITER_set(ohv, eiter);
1386 =for apidoc Am|HV *|hv_copy_hints_hv|HV *ohv
1388 A specialised version of L</newHVhv> for copying C<%^H>. I<ohv> must be
1389 a pointer to a hash (which may have C<%^H> magic, but should be generally
1390 non-magical), or C<NULL> (interpreted as an empty hash). The content
1391 of I<ohv> is copied to a new hash, which has the C<%^H>-specific magic
1392 added to it. A pointer to the new hash is returned.
1398 Perl_hv_copy_hints_hv(pTHX_ HV *const ohv)
1400 HV * const hv = newHV();
1402 if (ohv && HvTOTALKEYS(ohv)) {
1403 STRLEN hv_max = HvMAX(ohv);
1404 STRLEN hv_fill = HvFILL(ohv);
1406 const I32 riter = HvRITER_get(ohv);
1407 HE * const eiter = HvEITER_get(ohv);
1409 while (hv_max && hv_max + 1 >= hv_fill * 2)
1410 hv_max = hv_max / 2;
1414 while ((entry = hv_iternext_flags(ohv, 0))) {
1415 SV *const sv = newSVsv(HeVAL(entry));
1416 SV *heksv = newSVhek(HeKEY_hek(entry));
1417 sv_magic(sv, NULL, PERL_MAGIC_hintselem,
1418 (char *)heksv, HEf_SVKEY);
1419 SvREFCNT_dec(heksv);
1420 (void)hv_store_flags(hv, HeKEY(entry), HeKLEN(entry),
1421 sv, HeHASH(entry), HeKFLAGS(entry));
1423 HvRITER_set(ohv, riter);
1424 HvEITER_set(ohv, eiter);
1426 hv_magic(hv, NULL, PERL_MAGIC_hints);
1431 Perl_hv_free_ent(pTHX_ HV *hv, register HE *entry)
1436 PERL_ARGS_ASSERT_HV_FREE_ENT;
1441 if (val && isGV(val) && isGV_with_GP(val) && GvCVu(val) && HvNAME_get(hv))
1442 mro_method_changed_in(hv); /* deletion of method from stash */
1444 if (HeKLEN(entry) == HEf_SVKEY) {
1445 SvREFCNT_dec(HeKEY_sv(entry));
1446 Safefree(HeKEY_hek(entry));
1448 else if (HvSHAREKEYS(hv))
1449 unshare_hek(HeKEY_hek(entry));
1451 Safefree(HeKEY_hek(entry));
1457 Perl_hv_delayfree_ent(pTHX_ HV *hv, register HE *entry)
1461 PERL_ARGS_ASSERT_HV_DELAYFREE_ENT;
1465 /* SvREFCNT_inc to counter the SvREFCNT_dec in hv_free_ent */
1466 sv_2mortal(SvREFCNT_inc(HeVAL(entry))); /* free between statements */
1467 if (HeKLEN(entry) == HEf_SVKEY) {
1468 sv_2mortal(SvREFCNT_inc(HeKEY_sv(entry)));
1470 hv_free_ent(hv, entry);
1474 =for apidoc hv_clear
1476 Clears a hash, making it empty.
1482 Perl_hv_clear(pTHX_ HV *hv)
1485 register XPVHV* xhv;
1489 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1491 xhv = (XPVHV*)SvANY(hv);
1493 if (SvREADONLY(hv) && HvARRAY(hv) != NULL) {
1494 /* restricted hash: convert all keys to placeholders */
1496 for (i = 0; i <= xhv->xhv_max; i++) {
1497 HE *entry = (HvARRAY(hv))[i];
1498 for (; entry; entry = HeNEXT(entry)) {
1499 /* not already placeholder */
1500 if (HeVAL(entry) != &PL_sv_placeholder) {
1501 if (HeVAL(entry) && SvREADONLY(HeVAL(entry))) {
1502 SV* const keysv = hv_iterkeysv(entry);
1504 "Attempt to delete readonly key '%"SVf"' from a restricted hash",
1507 SvREFCNT_dec(HeVAL(entry));
1508 HeVAL(entry) = &PL_sv_placeholder;
1509 HvPLACEHOLDERS(hv)++;
1517 HvPLACEHOLDERS_set(hv, 0);
1519 Zero(HvARRAY(hv), xhv->xhv_max+1 /* HvMAX(hv)+1 */, HE*);
1522 mg_clear(MUTABLE_SV(hv));
1524 HvHASKFLAGS_off(hv);
1529 mro_isa_changed_in(hv);
1530 HvEITER_set(hv, NULL);
1535 =for apidoc hv_clear_placeholders
1537 Clears any placeholders from a hash. If a restricted hash has any of its keys
1538 marked as readonly and the key is subsequently deleted, the key is not actually
1539 deleted but is marked by assigning it a value of &PL_sv_placeholder. This tags
1540 it so it will be ignored by future operations such as iterating over the hash,
1541 but will still allow the hash to have a value reassigned to the key at some
1542 future point. This function clears any such placeholder keys from the hash.
1543 See Hash::Util::lock_keys() for an example of its use.
1549 Perl_hv_clear_placeholders(pTHX_ HV *hv)
1552 const U32 items = (U32)HvPLACEHOLDERS_get(hv);
1554 PERL_ARGS_ASSERT_HV_CLEAR_PLACEHOLDERS;
1557 clear_placeholders(hv, items);
1561 S_clear_placeholders(pTHX_ HV *hv, U32 items)
1566 PERL_ARGS_ASSERT_CLEAR_PLACEHOLDERS;
1573 /* Loop down the linked list heads */
1575 HE **oentry = &(HvARRAY(hv))[i];
1578 while ((entry = *oentry)) {
1579 if (HeVAL(entry) == &PL_sv_placeholder) {
1580 *oentry = HeNEXT(entry);
1581 if (entry == HvEITER_get(hv))
1584 hv_free_ent(hv, entry);
1588 HvTOTALKEYS(hv) -= (IV)HvPLACEHOLDERS_get(hv);
1589 if (HvKEYS(hv) == 0)
1590 HvHASKFLAGS_off(hv);
1591 HvPLACEHOLDERS_set(hv, 0);
1595 oentry = &HeNEXT(entry);
1600 /* You can't get here, hence assertion should always fail. */
1601 assert (items == 0);
1606 S_hfreeentries(pTHX_ HV *hv)
1608 /* This is the array that we're going to restore */
1609 HE **const orig_array = HvARRAY(hv);
1613 PERL_ARGS_ASSERT_HFREEENTRIES;
1619 /* If the hash is actually a symbol table with a name, look after the
1621 struct xpvhv_aux *iter = HvAUX(hv);
1623 name = iter->xhv_name;
1624 iter->xhv_name = NULL;
1629 /* orig_array remains unchanged throughout the loop. If after freeing all
1630 the entries it turns out that one of the little blighters has triggered
1631 an action that has caused HvARRAY to be re-allocated, then we set
1632 array to the new HvARRAY, and try again. */
1635 /* This is the one we're going to try to empty. First time round
1636 it's the original array. (Hopefully there will only be 1 time
1638 HE ** const array = HvARRAY(hv);
1641 /* Because we have taken xhv_name out, the only allocated pointer
1642 in the aux structure that might exist is the backreference array.
1647 struct mro_meta *meta;
1648 struct xpvhv_aux *iter = HvAUX(hv);
1649 /* weak references: if called from sv_clear(), the backrefs
1650 * should already have been killed; if there are any left, its
1651 * because we're doing hv_clear() or hv_undef(), and the HV
1652 * will continue to live.
1653 * Because while freeing the entries we fake up a NULL HvARRAY
1654 * (and hence HvAUX), we need to store the backref array
1655 * somewhere else; but it still needs to be visible in case
1656 * any the things we free happen to call sv_del_backref().
1657 * We do this by storing it in magic instead.
1658 * If, during the entry freeing, a destructor happens to add
1659 * a new weak backref, then sv_add_backref will look in both
1660 * places (magic in HvAUX) for the AV, but will create a new
1661 * AV in HvAUX if it can't find one (if it finds it in magic,
1662 * it moves it back into HvAUX. So at the end of the iteration
1663 * we have to allow for this. */
1666 if (iter->xhv_backreferences) {
1667 if (SvTYPE(iter->xhv_backreferences) == SVt_PVAV) {
1668 /* The sv_magic will increase the reference count of the AV,
1669 so we need to drop it first. */
1670 SvREFCNT_dec(iter->xhv_backreferences);
1671 if (AvFILLp(iter->xhv_backreferences) == -1) {
1672 /* Turns out that the array is empty. Just free it. */
1673 SvREFCNT_dec(iter->xhv_backreferences);
1676 sv_magic(MUTABLE_SV(hv),
1677 MUTABLE_SV(iter->xhv_backreferences),
1678 PERL_MAGIC_backref, NULL, 0);
1683 sv_magic(MUTABLE_SV(hv), NULL, PERL_MAGIC_backref, NULL, 0);
1684 mg = mg_find(MUTABLE_SV(hv), PERL_MAGIC_backref);
1685 mg->mg_obj = (SV*)iter->xhv_backreferences;
1687 iter->xhv_backreferences = NULL;
1690 entry = iter->xhv_eiter; /* HvEITER(hv) */
1691 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1693 hv_free_ent(hv, entry);
1695 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1696 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1698 if((meta = iter->xhv_mro_meta)) {
1699 if (meta->mro_linear_all) {
1700 SvREFCNT_dec(MUTABLE_SV(meta->mro_linear_all));
1701 meta->mro_linear_all = NULL;
1702 /* This is just acting as a shortcut pointer. */
1703 meta->mro_linear_current = NULL;
1704 } else if (meta->mro_linear_current) {
1705 /* Only the current MRO is stored, so this owns the data.
1707 SvREFCNT_dec(meta->mro_linear_current);
1708 meta->mro_linear_current = NULL;
1710 if(meta->mro_nextmethod) SvREFCNT_dec(meta->mro_nextmethod);
1711 SvREFCNT_dec(meta->isa);
1713 iter->xhv_mro_meta = NULL;
1716 /* There are now no allocated pointers in the aux structure. */
1718 SvFLAGS(hv) &= ~SVf_OOK; /* Goodbye, aux structure. */
1719 /* What aux structure? */
1722 /* make everyone else think the array is empty, so that the destructors
1723 * called for freed entries can't recursively mess with us */
1725 ((XPVHV*) SvANY(hv))->xhv_keys = 0;
1729 /* Loop down the linked list heads */
1730 HE *entry = array[i];
1733 register HE * const oentry = entry;
1734 entry = HeNEXT(entry);
1735 hv_free_ent(hv, oentry);
1739 /* As there are no allocated pointers in the aux structure, it's now
1740 safe to free the array we just cleaned up, if it's not the one we're
1741 going to put back. */
1742 if (array != orig_array) {
1747 /* Good. No-one added anything this time round. */
1752 /* Someone attempted to iterate or set the hash name while we had
1753 the array set to 0. We'll catch backferences on the next time
1754 round the while loop. */
1755 assert(HvARRAY(hv));
1757 if (HvAUX(hv)->xhv_name) {
1758 unshare_hek_or_pvn(HvAUX(hv)->xhv_name, 0, 0, 0);
1762 if (--attempts == 0) {
1763 Perl_die(aTHX_ "panic: hfreeentries failed to free hash - something is repeatedly re-creating entries");
1767 HvARRAY(hv) = orig_array;
1769 /* If the hash was actually a symbol table, put the name back. */
1771 /* We have restored the original array. If name is non-NULL, then
1772 the original array had an aux structure at the end. So this is
1774 SvFLAGS(hv) |= SVf_OOK;
1775 HvAUX(hv)->xhv_name = name;
1780 =for apidoc hv_undef
1788 Perl_hv_undef(pTHX_ HV *hv)
1791 register XPVHV* xhv;
1796 DEBUG_A(Perl_hv_assert(aTHX_ hv));
1797 xhv = (XPVHV*)SvANY(hv);
1799 if ((name = HvNAME_get(hv)) && !PL_dirty)
1800 mro_isa_changed_in(hv);
1805 (void)hv_delete(PL_stashcache, name, HvNAMELEN_get(hv), G_DISCARD);
1806 hv_name_set(hv, NULL, 0, 0);
1808 SvFLAGS(hv) &= ~SVf_OOK;
1809 Safefree(HvARRAY(hv));
1810 xhv->xhv_max = 7; /* HvMAX(hv) = 7 (it's a normal hash) */
1812 HvPLACEHOLDERS_set(hv, 0);
1815 mg_clear(MUTABLE_SV(hv));
1821 Returns the number of hash buckets that happen to be in use. This function is
1822 wrapped by the macro C<HvFILL>.
1824 Previously this value was stored in the HV structure, rather than being
1825 calculated on demand.
1831 Perl_hv_fill(pTHX_ HV const *const hv)
1834 HE **ents = HvARRAY(hv);
1836 PERL_ARGS_ASSERT_HV_FILL;
1839 HE *const *const last = ents + HvMAX(hv);
1840 count = last + 1 - ents;
1845 } while (++ents <= last);
1850 static struct xpvhv_aux*
1851 S_hv_auxinit(HV *hv) {
1852 struct xpvhv_aux *iter;
1855 PERL_ARGS_ASSERT_HV_AUXINIT;
1858 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1859 + sizeof(struct xpvhv_aux), char);
1861 array = (char *) HvARRAY(hv);
1862 Renew(array, PERL_HV_ARRAY_ALLOC_BYTES(HvMAX(hv) + 1)
1863 + sizeof(struct xpvhv_aux), char);
1865 HvARRAY(hv) = (HE**) array;
1866 /* SvOOK_on(hv) attacks the IV flags. */
1867 SvFLAGS(hv) |= SVf_OOK;
1870 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1871 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1873 iter->xhv_backreferences = 0;
1874 iter->xhv_mro_meta = NULL;
1879 =for apidoc hv_iterinit
1881 Prepares a starting point to traverse a hash table. Returns the number of
1882 keys in the hash (i.e. the same as C<HvKEYS(hv)>). The return value is
1883 currently only meaningful for hashes without tie magic.
1885 NOTE: Before version 5.004_65, C<hv_iterinit> used to return the number of
1886 hash buckets that happen to be in use. If you still need that esoteric
1887 value, you can get it through the macro C<HvFILL(hv)>.
1894 Perl_hv_iterinit(pTHX_ HV *hv)
1896 PERL_ARGS_ASSERT_HV_ITERINIT;
1898 /* FIXME: Are we not NULL, or do we croak? Place bets now! */
1901 Perl_croak(aTHX_ "Bad hash");
1904 struct xpvhv_aux * const iter = HvAUX(hv);
1905 HE * const entry = iter->xhv_eiter; /* HvEITER(hv) */
1906 if (entry && HvLAZYDEL(hv)) { /* was deleted earlier? */
1908 hv_free_ent(hv, entry);
1910 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
1911 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
1916 /* used to be xhv->xhv_fill before 5.004_65 */
1917 return HvTOTALKEYS(hv);
1921 Perl_hv_riter_p(pTHX_ HV *hv) {
1922 struct xpvhv_aux *iter;
1924 PERL_ARGS_ASSERT_HV_RITER_P;
1927 Perl_croak(aTHX_ "Bad hash");
1929 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1930 return &(iter->xhv_riter);
1934 Perl_hv_eiter_p(pTHX_ HV *hv) {
1935 struct xpvhv_aux *iter;
1937 PERL_ARGS_ASSERT_HV_EITER_P;
1940 Perl_croak(aTHX_ "Bad hash");
1942 iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
1943 return &(iter->xhv_eiter);
1947 Perl_hv_riter_set(pTHX_ HV *hv, I32 riter) {
1948 struct xpvhv_aux *iter;
1950 PERL_ARGS_ASSERT_HV_RITER_SET;
1953 Perl_croak(aTHX_ "Bad hash");
1961 iter = hv_auxinit(hv);
1963 iter->xhv_riter = riter;
1967 Perl_hv_eiter_set(pTHX_ HV *hv, HE *eiter) {
1968 struct xpvhv_aux *iter;
1970 PERL_ARGS_ASSERT_HV_EITER_SET;
1973 Perl_croak(aTHX_ "Bad hash");
1978 /* 0 is the default so don't go malloc()ing a new structure just to
1983 iter = hv_auxinit(hv);
1985 iter->xhv_eiter = eiter;
1989 Perl_hv_name_set(pTHX_ HV *hv, const char *name, U32 len, U32 flags)
1992 struct xpvhv_aux *iter;
1995 PERL_ARGS_ASSERT_HV_NAME_SET;
1996 PERL_UNUSED_ARG(flags);
1999 Perl_croak(aTHX_ "panic: hv name too long (%"UVuf")", (UV) len);
2003 if (iter->xhv_name) {
2004 unshare_hek_or_pvn(iter->xhv_name, 0, 0, 0);
2010 iter = hv_auxinit(hv);
2012 PERL_HASH(hash, name, len);
2013 iter->xhv_name = name ? share_hek(name, len, hash) : NULL;
2017 Perl_hv_backreferences_p(pTHX_ HV *hv) {
2018 struct xpvhv_aux * const iter = SvOOK(hv) ? HvAUX(hv) : hv_auxinit(hv);
2020 PERL_ARGS_ASSERT_HV_BACKREFERENCES_P;
2021 PERL_UNUSED_CONTEXT;
2023 return &(iter->xhv_backreferences);
2027 Perl_hv_kill_backrefs(pTHX_ HV *hv) {
2030 PERL_ARGS_ASSERT_HV_KILL_BACKREFS;
2035 av = HvAUX(hv)->xhv_backreferences;
2038 HvAUX(hv)->xhv_backreferences = 0;
2039 Perl_sv_kill_backrefs(aTHX_ MUTABLE_SV(hv), av);
2040 if (SvTYPE(av) == SVt_PVAV)
2046 hv_iternext is implemented as a macro in hv.h
2048 =for apidoc hv_iternext
2050 Returns entries from a hash iterator. See C<hv_iterinit>.
2052 You may call C<hv_delete> or C<hv_delete_ent> on the hash entry that the
2053 iterator currently points to, without losing your place or invalidating your
2054 iterator. Note that in this case the current entry is deleted from the hash
2055 with your iterator holding the last reference to it. Your iterator is flagged
2056 to free the entry on the next call to C<hv_iternext>, so you must not discard
2057 your iterator immediately else the entry will leak - call C<hv_iternext> to
2058 trigger the resource deallocation.
2060 =for apidoc hv_iternext_flags
2062 Returns entries from a hash iterator. See C<hv_iterinit> and C<hv_iternext>.
2063 The C<flags> value will normally be zero; if HV_ITERNEXT_WANTPLACEHOLDERS is
2064 set the placeholders keys (for restricted hashes) will be returned in addition
2065 to normal keys. By default placeholders are automatically skipped over.
2066 Currently a placeholder is implemented with a value that is
2067 C<&Perl_sv_placeholder>. Note that the implementation of placeholders and
2068 restricted hashes may change, and the implementation currently is
2069 insufficiently abstracted for any change to be tidy.
2075 Perl_hv_iternext_flags(pTHX_ HV *hv, I32 flags)
2078 register XPVHV* xhv;
2082 struct xpvhv_aux *iter;
2084 PERL_ARGS_ASSERT_HV_ITERNEXT_FLAGS;
2087 Perl_croak(aTHX_ "Bad hash");
2089 xhv = (XPVHV*)SvANY(hv);
2092 /* Too many things (well, pp_each at least) merrily assume that you can
2093 call iv_iternext without calling hv_iterinit, so we'll have to deal
2099 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2100 if (SvMAGICAL(hv) && SvRMAGICAL(hv)) {
2101 if ( ( mg = mg_find((const SV *)hv, PERL_MAGIC_tied) ) ) {
2102 SV * const key = sv_newmortal();
2104 sv_setsv(key, HeSVKEY_force(entry));
2105 SvREFCNT_dec(HeSVKEY(entry)); /* get rid of previous key */
2111 /* one HE per MAGICAL hash */
2112 iter->xhv_eiter = entry = new_HE(); /* HvEITER(hv) = new_HE() */
2114 Newxz(k, HEK_BASESIZE + sizeof(const SV *), char);
2116 HeKEY_hek(entry) = hek;
2117 HeKLEN(entry) = HEf_SVKEY;
2119 magic_nextpack(MUTABLE_SV(hv),mg,key);
2121 /* force key to stay around until next time */
2122 HeSVKEY_set(entry, SvREFCNT_inc_simple_NN(key));
2123 return entry; /* beware, hent_val is not set */
2125 SvREFCNT_dec(HeVAL(entry));
2126 Safefree(HeKEY_hek(entry));
2128 iter->xhv_eiter = NULL; /* HvEITER(hv) = NULL */
2132 #if defined(DYNAMIC_ENV_FETCH) && !defined(__riscos__) /* set up %ENV for iteration */
2133 if (!entry && SvRMAGICAL((const SV *)hv)
2134 && mg_find((const SV *)hv, PERL_MAGIC_env)) {
2137 /* The prime_env_iter() on VMS just loaded up new hash values
2138 * so the iteration count needs to be reset back to the beginning
2142 oldentry = entry = iter->xhv_eiter; /* HvEITER(hv) */
2147 /* hv_iterint now ensures this. */
2148 assert (HvARRAY(hv));
2150 /* At start of hash, entry is NULL. */
2153 entry = HeNEXT(entry);
2154 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2156 * Skip past any placeholders -- don't want to include them in
2159 while (entry && HeVAL(entry) == &PL_sv_placeholder) {
2160 entry = HeNEXT(entry);
2165 /* Skip the entire loop if the hash is empty. */
2166 if ((flags & HV_ITERNEXT_WANTPLACEHOLDERS)
2167 ? HvTOTALKEYS(hv) : HvUSEDKEYS(hv)) {
2169 /* OK. Come to the end of the current list. Grab the next one. */
2171 iter->xhv_riter++; /* HvRITER(hv)++ */
2172 if (iter->xhv_riter > (I32)xhv->xhv_max /* HvRITER(hv) > HvMAX(hv) */) {
2173 /* There is no next one. End of the hash. */
2174 iter->xhv_riter = -1; /* HvRITER(hv) = -1 */
2177 entry = (HvARRAY(hv))[iter->xhv_riter];
2179 if (!(flags & HV_ITERNEXT_WANTPLACEHOLDERS)) {
2180 /* If we have an entry, but it's a placeholder, don't count it.
2182 while (entry && HeVAL(entry) == &PL_sv_placeholder)
2183 entry = HeNEXT(entry);
2185 /* Will loop again if this linked list starts NULL
2186 (for HV_ITERNEXT_WANTPLACEHOLDERS)
2187 or if we run through it and find only placeholders. */
2191 if (oldentry && HvLAZYDEL(hv)) { /* was deleted earlier? */
2193 hv_free_ent(hv, oldentry);
2196 /*if (HvREHASH(hv) && entry && !HeKREHASH(entry))
2197 PerlIO_printf(PerlIO_stderr(), "Awooga %p %p\n", (void*)hv, (void*)entry);*/
2199 iter->xhv_eiter = entry; /* HvEITER(hv) = entry */
2204 =for apidoc hv_iterkey
2206 Returns the key from the current position of the hash iterator. See
2213 Perl_hv_iterkey(pTHX_ register HE *entry, I32 *retlen)
2215 PERL_ARGS_ASSERT_HV_ITERKEY;
2217 if (HeKLEN(entry) == HEf_SVKEY) {
2219 char * const p = SvPV(HeKEY_sv(entry), len);
2224 *retlen = HeKLEN(entry);
2225 return HeKEY(entry);
2229 /* unlike hv_iterval(), this always returns a mortal copy of the key */
2231 =for apidoc hv_iterkeysv
2233 Returns the key as an C<SV*> from the current position of the hash
2234 iterator. The return value will always be a mortal copy of the key. Also
2241 Perl_hv_iterkeysv(pTHX_ register HE *entry)
2243 PERL_ARGS_ASSERT_HV_ITERKEYSV;
2245 return sv_2mortal(newSVhek(HeKEY_hek(entry)));
2249 =for apidoc hv_iterval
2251 Returns the value from the current position of the hash iterator. See
2258 Perl_hv_iterval(pTHX_ HV *hv, register HE *entry)
2260 PERL_ARGS_ASSERT_HV_ITERVAL;
2262 if (SvRMAGICAL(hv)) {
2263 if (mg_find((const SV *)hv, PERL_MAGIC_tied)) {
2264 SV* const sv = sv_newmortal();
2265 if (HeKLEN(entry) == HEf_SVKEY)
2266 mg_copy(MUTABLE_SV(hv), sv, (char*)HeKEY_sv(entry), HEf_SVKEY);
2268 mg_copy(MUTABLE_SV(hv), sv, HeKEY(entry), HeKLEN(entry));
2272 return HeVAL(entry);
2276 =for apidoc hv_iternextsv
2278 Performs an C<hv_iternext>, C<hv_iterkey>, and C<hv_iterval> in one
2285 Perl_hv_iternextsv(pTHX_ HV *hv, char **key, I32 *retlen)
2287 HE * const he = hv_iternext_flags(hv, 0);
2289 PERL_ARGS_ASSERT_HV_ITERNEXTSV;
2293 *key = hv_iterkey(he, retlen);
2294 return hv_iterval(hv, he);
2301 =for apidoc hv_magic
2303 Adds magic to a hash. See C<sv_magic>.
2308 /* possibly free a shared string if no one has access to it
2309 * len and hash must both be valid for str.
2312 Perl_unsharepvn(pTHX_ const char *str, I32 len, U32 hash)
2314 unshare_hek_or_pvn (NULL, str, len, hash);
2319 Perl_unshare_hek(pTHX_ HEK *hek)
2322 unshare_hek_or_pvn(hek, NULL, 0, 0);
2325 /* possibly free a shared string if no one has access to it
2326 hek if non-NULL takes priority over the other 3, else str, len and hash
2327 are used. If so, len and hash must both be valid for str.
2330 S_unshare_hek_or_pvn(pTHX_ const HEK *hek, const char *str, I32 len, U32 hash)
2333 register XPVHV* xhv;
2335 register HE **oentry;
2337 bool is_utf8 = FALSE;
2339 const char * const save = str;
2340 struct shared_he *he = NULL;
2343 /* Find the shared he which is just before us in memory. */
2344 he = (struct shared_he *)(((char *)hek)
2345 - STRUCT_OFFSET(struct shared_he,
2348 /* Assert that the caller passed us a genuine (or at least consistent)
2350 assert (he->shared_he_he.hent_hek == hek);
2352 if (he->shared_he_he.he_valu.hent_refcount - 1) {
2353 --he->shared_he_he.he_valu.hent_refcount;
2357 hash = HEK_HASH(hek);
2358 } else if (len < 0) {
2359 STRLEN tmplen = -len;
2361 /* See the note in hv_fetch(). --jhi */
2362 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2365 k_flags = HVhek_UTF8;
2367 k_flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2370 /* what follows was the moral equivalent of:
2371 if ((Svp = hv_fetch(PL_strtab, tmpsv, FALSE, hash))) {
2373 hv_delete(PL_strtab, str, len, G_DISCARD, hash);
2375 xhv = (XPVHV*)SvANY(PL_strtab);
2376 /* assert(xhv_array != 0) */
2377 first = oentry = &(HvARRAY(PL_strtab))[hash & (I32) HvMAX(PL_strtab)];
2379 const HE *const he_he = &(he->shared_he_he);
2380 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2385 const int flags_masked = k_flags & HVhek_MASK;
2386 for (entry = *oentry; entry; oentry = &HeNEXT(entry), entry = *oentry) {
2387 if (HeHASH(entry) != hash) /* strings can't be equal */
2389 if (HeKLEN(entry) != len)
2391 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2393 if (HeKFLAGS(entry) != flags_masked)
2400 if (--entry->he_valu.hent_refcount == 0) {
2401 *oentry = HeNEXT(entry);
2403 xhv->xhv_keys--; /* HvTOTALKEYS(hv)-- */
2408 Perl_ck_warner_d(aTHX_ packWARN(WARN_INTERNAL),
2409 "Attempt to free non-existent shared string '%s'%s"
2411 hek ? HEK_KEY(hek) : str,
2412 ((k_flags & HVhek_UTF8) ? " (utf8)" : "") pTHX__VALUE);
2413 if (k_flags & HVhek_FREEKEY)
2417 /* get a (constant) string ptr from the global string table
2418 * string will get added if it is not already there.
2419 * len and hash must both be valid for str.
2422 Perl_share_hek(pTHX_ const char *str, I32 len, register U32 hash)
2424 bool is_utf8 = FALSE;
2426 const char * const save = str;
2428 PERL_ARGS_ASSERT_SHARE_HEK;
2431 STRLEN tmplen = -len;
2433 /* See the note in hv_fetch(). --jhi */
2434 str = (char*)bytes_from_utf8((U8*)str, &tmplen, &is_utf8);
2436 /* If we were able to downgrade here, then than means that we were passed
2437 in a key which only had chars 0-255, but was utf8 encoded. */
2440 /* If we found we were able to downgrade the string to bytes, then
2441 we should flag that it needs upgrading on keys or each. Also flag
2442 that we need share_hek_flags to free the string. */
2444 flags |= HVhek_WASUTF8 | HVhek_FREEKEY;
2447 return share_hek_flags (str, len, hash, flags);
2451 S_share_hek_flags(pTHX_ const char *str, I32 len, register U32 hash, int flags)
2455 const int flags_masked = flags & HVhek_MASK;
2456 const U32 hindex = hash & (I32) HvMAX(PL_strtab);
2457 register XPVHV * const xhv = (XPVHV*)SvANY(PL_strtab);
2459 PERL_ARGS_ASSERT_SHARE_HEK_FLAGS;
2461 /* what follows is the moral equivalent of:
2463 if (!(Svp = hv_fetch(PL_strtab, str, len, FALSE)))
2464 hv_store(PL_strtab, str, len, NULL, hash);
2466 Can't rehash the shared string table, so not sure if it's worth
2467 counting the number of entries in the linked list
2470 /* assert(xhv_array != 0) */
2471 entry = (HvARRAY(PL_strtab))[hindex];
2472 for (;entry; entry = HeNEXT(entry)) {
2473 if (HeHASH(entry) != hash) /* strings can't be equal */
2475 if (HeKLEN(entry) != len)
2477 if (HeKEY(entry) != str && memNE(HeKEY(entry),str,len)) /* is this it? */
2479 if (HeKFLAGS(entry) != flags_masked)
2485 /* What used to be head of the list.
2486 If this is NULL, then we're the first entry for this slot, which
2487 means we need to increate fill. */
2488 struct shared_he *new_entry;
2491 HE **const head = &HvARRAY(PL_strtab)[hindex];
2492 HE *const next = *head;
2494 /* We don't actually store a HE from the arena and a regular HEK.
2495 Instead we allocate one chunk of memory big enough for both,
2496 and put the HEK straight after the HE. This way we can find the
2497 HEK directly from the HE.
2500 Newx(k, STRUCT_OFFSET(struct shared_he,
2501 shared_he_hek.hek_key[0]) + len + 2, char);
2502 new_entry = (struct shared_he *)k;
2503 entry = &(new_entry->shared_he_he);
2504 hek = &(new_entry->shared_he_hek);
2506 Copy(str, HEK_KEY(hek), len, char);
2507 HEK_KEY(hek)[len] = 0;
2509 HEK_HASH(hek) = hash;
2510 HEK_FLAGS(hek) = (unsigned char)flags_masked;
2512 /* Still "point" to the HEK, so that other code need not know what
2514 HeKEY_hek(entry) = hek;
2515 entry->he_valu.hent_refcount = 0;
2516 HeNEXT(entry) = next;
2519 xhv->xhv_keys++; /* HvTOTALKEYS(hv)++ */
2520 if (!next) { /* initial entry? */
2521 } else if (xhv->xhv_keys > xhv->xhv_max /* HvKEYS(hv) > HvMAX(hv) */) {
2526 ++entry->he_valu.hent_refcount;
2528 if (flags & HVhek_FREEKEY)
2531 return HeKEY_hek(entry);
2535 Perl_hv_placeholders_p(pTHX_ HV *hv)
2538 MAGIC *mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2540 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_P;
2543 mg = sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, 0);
2546 Perl_die(aTHX_ "panic: hv_placeholders_p");
2549 return &(mg->mg_len);
2554 Perl_hv_placeholders_get(pTHX_ const HV *hv)
2557 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2559 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_GET;
2561 return mg ? mg->mg_len : 0;
2565 Perl_hv_placeholders_set(pTHX_ HV *hv, I32 ph)
2568 MAGIC * const mg = mg_find((const SV *)hv, PERL_MAGIC_rhash);
2570 PERL_ARGS_ASSERT_HV_PLACEHOLDERS_SET;
2575 if (!sv_magicext(MUTABLE_SV(hv), 0, PERL_MAGIC_rhash, 0, 0, ph))
2576 Perl_die(aTHX_ "panic: hv_placeholders_set");
2578 /* else we don't need to add magic to record 0 placeholders. */
2582 S_refcounted_he_value(pTHX_ const struct refcounted_he *he)
2587 PERL_ARGS_ASSERT_REFCOUNTED_HE_VALUE;
2589 switch(he->refcounted_he_data[0] & HVrhek_typemask) {
2594 value = &PL_sv_placeholder;
2597 value = newSViv(he->refcounted_he_val.refcounted_he_u_iv);
2600 value = newSVuv(he->refcounted_he_val.refcounted_he_u_uv);
2603 case HVrhek_PV_UTF8:
2604 /* Create a string SV that directly points to the bytes in our
2606 value = newSV_type(SVt_PV);
2607 SvPV_set(value, (char *) he->refcounted_he_data + 1);
2608 SvCUR_set(value, he->refcounted_he_val.refcounted_he_u_len);
2609 /* This stops anything trying to free it */
2610 SvLEN_set(value, 0);
2612 SvREADONLY_on(value);
2613 if ((he->refcounted_he_data[0] & HVrhek_typemask) == HVrhek_PV_UTF8)
2617 Perl_croak(aTHX_ "panic: refcounted_he_value bad flags %x",
2618 he->refcounted_he_data[0]);
2624 =for apidoc cop_hints_2hv
2626 Generates and returns a C<HV *> from the hinthash in the provided
2627 C<COP>. Returns C<NULL> if there isn't one there.
2632 Perl_cop_hints_2hv(pTHX_ const COP *cop)
2634 PERL_ARGS_ASSERT_COP_HINTS_2HV;
2636 if (!cop->cop_hints_hash)
2639 return Perl_refcounted_he_chain_2hv(aTHX_ cop->cop_hints_hash);
2643 =for apidoc cop_hints_fetchsv
2645 Fetches an entry from the hinthash in the provided C<COP>. Returns NULL
2646 if the entry isn't there.
2648 =for apidoc cop_hints_fetchpvn
2650 See L</cop_hints_fetchsv>. If C<flags> includes C<HVhek_UTF8>, C<key> is
2653 =for apidoc cop_hints_fetchpvs
2655 See L</cop_hints_fetchpvn>. This is a macro that takes a constant string
2656 for its argument, which is assumed to be ASCII (rather than UTF-8).
2661 Perl_cop_hints_fetchpvn(pTHX_ const COP *cop, const char *key, STRLEN klen,
2662 int flags, U32 hash)
2664 PERL_ARGS_ASSERT_COP_HINTS_FETCHPVN;
2666 /* refcounted_he_fetch takes more flags than we do. Make sure
2667 * noone's depending on being able to pass them here. */
2668 flags &= ~HVhek_UTF8;
2670 return Perl_refcounted_he_fetch(aTHX_ cop->cop_hints_hash, NULL,
2671 key, klen, flags, hash);
2675 =for apidoc refcounted_he_chain_2hv
2677 Generates and returns a C<HV *> by walking up the tree starting at the passed
2678 in C<struct refcounted_he *>.
2683 Perl_refcounted_he_chain_2hv(pTHX_ const struct refcounted_he *chain)
2687 U32 placeholders = 0;
2688 /* We could chase the chain once to get an idea of the number of keys,
2689 and call ksplit. But for now we'll make a potentially inefficient
2690 hash with only 8 entries in its array. */
2691 const U32 max = HvMAX(hv);
2695 Newxz(array, PERL_HV_ARRAY_ALLOC_BYTES(max + 1), char);
2696 HvARRAY(hv) = (HE**)array;
2701 U32 hash = chain->refcounted_he_hash;
2703 U32 hash = HEK_HASH(chain->refcounted_he_hek);
2705 HE **oentry = &((HvARRAY(hv))[hash & max]);
2706 HE *entry = *oentry;
2709 for (; entry; entry = HeNEXT(entry)) {
2710 if (HeHASH(entry) == hash) {
2711 /* We might have a duplicate key here. If so, entry is older
2712 than the key we've already put in the hash, so if they are
2713 the same, skip adding entry. */
2715 const STRLEN klen = HeKLEN(entry);
2716 const char *const key = HeKEY(entry);
2717 if (klen == chain->refcounted_he_keylen
2718 && (!!HeKUTF8(entry)
2719 == !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2720 && memEQ(key, REF_HE_KEY(chain), klen))
2723 if (HeKEY_hek(entry) == chain->refcounted_he_hek)
2725 if (HeKLEN(entry) == HEK_LEN(chain->refcounted_he_hek)
2726 && HeKUTF8(entry) == HEK_UTF8(chain->refcounted_he_hek)
2727 && memEQ(HeKEY(entry), HEK_KEY(chain->refcounted_he_hek),
2738 = share_hek_flags(REF_HE_KEY(chain),
2739 chain->refcounted_he_keylen,
2740 chain->refcounted_he_hash,
2741 (chain->refcounted_he_data[0]
2742 & (HVhek_UTF8|HVhek_WASUTF8)));
2744 HeKEY_hek(entry) = share_hek_hek(chain->refcounted_he_hek);
2746 value = refcounted_he_value(chain);
2747 if (value == &PL_sv_placeholder)
2749 HeVAL(entry) = value;
2751 /* Link it into the chain. */
2752 HeNEXT(entry) = *oentry;
2758 chain = chain->refcounted_he_next;
2762 clear_placeholders(hv, placeholders);
2763 HvTOTALKEYS(hv) -= placeholders;
2766 /* We could check in the loop to see if we encounter any keys with key
2767 flags, but it's probably not worth it, as this per-hash flag is only
2768 really meant as an optimisation for things like Storable. */
2770 DEBUG_A(Perl_hv_assert(aTHX_ hv));
2776 Perl_refcounted_he_fetch(pTHX_ const struct refcounted_he *chain, SV *keysv,
2777 const char *key, STRLEN klen, int flags, U32 hash)
2780 /* Just to be awkward, if you're using this interface the UTF-8-or-not-ness
2781 of your key has to exactly match that which is stored. */
2782 SV *value = &PL_sv_placeholder;
2785 /* No point in doing any of this if there's nothing to find. */
2789 if (flags & HVhek_FREEKEY)
2791 key = SvPV_const(keysv, klen);
2793 is_utf8 = (SvUTF8(keysv) != 0);
2795 is_utf8 = ((flags & HVhek_UTF8) ? TRUE : FALSE);
2799 if (keysv && (SvIsCOW_shared_hash(keysv))) {
2800 hash = SvSHARED_HASH(keysv);
2802 PERL_HASH(hash, key, klen);
2806 for (; chain; chain = chain->refcounted_he_next) {
2808 if (hash != chain->refcounted_he_hash)
2810 if (klen != chain->refcounted_he_keylen)
2812 if (memNE(REF_HE_KEY(chain),key,klen))
2814 if (!!is_utf8 != !!(chain->refcounted_he_data[0] & HVhek_UTF8))
2817 if (hash != HEK_HASH(chain->refcounted_he_hek))
2819 if (klen != (STRLEN)HEK_LEN(chain->refcounted_he_hek))
2821 if (memNE(HEK_KEY(chain->refcounted_he_hek),key,klen))
2823 if (!!is_utf8 != !!HEK_UTF8(chain->refcounted_he_hek))
2827 value = sv_2mortal(refcounted_he_value(chain));
2832 if (flags & HVhek_FREEKEY)
2839 =for apidoc refcounted_he_new
2841 Creates a new C<struct refcounted_he>. As S<key> is copied, and value is
2842 stored in a compact form, all references remain the property of the caller.
2843 The C<struct refcounted_he> is returned with a reference count of 1.
2848 struct refcounted_he *
2849 Perl_refcounted_he_new(pTHX_ struct refcounted_he *const parent,
2850 SV *const key, SV *const value) {
2853 const char *key_p = SvPV_const(key, key_len);
2854 STRLEN value_len = 0;
2855 const char *value_p = NULL;
2858 bool is_utf8 = SvUTF8(key) ? TRUE : FALSE;
2861 value_type = HVrhek_PV;
2862 } else if (SvIOK(value)) {
2863 value_type = SvUOK((const SV *)value) ? HVrhek_UV : HVrhek_IV;
2864 } else if (value == &PL_sv_placeholder) {
2865 value_type = HVrhek_delete;
2866 } else if (!SvOK(value)) {
2867 value_type = HVrhek_undef;
2869 value_type = HVrhek_PV;
2872 if (value_type == HVrhek_PV) {
2873 /* Do it this way so that the SvUTF8() test is after the SvPV, in case
2874 the value is overloaded, and doesn't yet have the UTF-8flag set. */
2875 value_p = SvPV_const(value, value_len);
2877 value_type = HVrhek_PV_UTF8;
2882 /* Hash keys are always stored normalised to (yes) ISO-8859-1.
2883 As we're going to be building hash keys from this value in future,
2884 normalise it now. */
2885 key_p = (char*)bytes_from_utf8((const U8*)key_p, &key_len, &is_utf8);
2886 flags |= is_utf8 ? HVhek_UTF8 : HVhek_WASUTF8;
2889 return refcounted_he_new_common(parent, key_p, key_len, flags, value_type,
2890 ((value_type == HVrhek_PV
2891 || value_type == HVrhek_PV_UTF8) ?
2892 (void *)value_p : (void *)value),
2896 static struct refcounted_he *
2897 S_refcounted_he_new_common(pTHX_ struct refcounted_he *const parent,
2898 const char *const key_p, const STRLEN key_len,
2899 const char flags, char value_type,
2900 const void *value, const STRLEN value_len) {
2902 struct refcounted_he *he;
2904 const bool is_pv = value_type == HVrhek_PV || value_type == HVrhek_PV_UTF8;
2905 STRLEN key_offset = is_pv ? value_len + 2 : 1;
2907 PERL_ARGS_ASSERT_REFCOUNTED_HE_NEW_COMMON;
2910 he = (struct refcounted_he*)
2911 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2915 he = (struct refcounted_he*)
2916 PerlMemShared_malloc(sizeof(struct refcounted_he) - 1
2920 he->refcounted_he_next = parent;
2923 Copy((char *)value, he->refcounted_he_data + 1, value_len + 1, char);
2924 he->refcounted_he_val.refcounted_he_u_len = value_len;
2925 } else if (value_type == HVrhek_IV) {
2926 he->refcounted_he_val.refcounted_he_u_iv = SvIVX((const SV *)value);
2927 } else if (value_type == HVrhek_UV) {
2928 he->refcounted_he_val.refcounted_he_u_uv = SvUVX((const SV *)value);
2931 PERL_HASH(hash, key_p, key_len);
2934 he->refcounted_he_hash = hash;
2935 he->refcounted_he_keylen = key_len;
2936 Copy(key_p, he->refcounted_he_data + key_offset, key_len, char);
2938 he->refcounted_he_hek = share_hek_flags(key_p, key_len, hash, flags);
2941 if (flags & HVhek_WASUTF8) {
2942 /* If it was downgraded from UTF-8, then the pointer returned from
2943 bytes_from_utf8 is an allocated pointer that we must free. */
2947 he->refcounted_he_data[0] = flags;
2948 he->refcounted_he_refcnt = 1;
2954 =for apidoc refcounted_he_free
2956 Decrements the reference count of the passed in C<struct refcounted_he *>
2957 by one. If the reference count reaches zero the structure's memory is freed,
2958 and C<refcounted_he_free> iterates onto the parent node.
2964 Perl_refcounted_he_free(pTHX_ struct refcounted_he *he) {
2966 PERL_UNUSED_CONTEXT;
2969 struct refcounted_he *copy;
2973 new_count = --he->refcounted_he_refcnt;
2974 HINTS_REFCNT_UNLOCK;
2980 #ifndef USE_ITHREADS
2981 unshare_hek_or_pvn (he->refcounted_he_hek, 0, 0, 0);
2984 he = he->refcounted_he_next;
2985 PerlMemShared_free(copy);
2989 /* pp_entereval is aware that labels are stored with a key ':' at the top of
2992 Perl_fetch_cop_label(pTHX_ COP *const cop, STRLEN *len, U32 *flags) {
2993 struct refcounted_he *const chain = cop->cop_hints_hash;
2995 PERL_ARGS_ASSERT_FETCH_COP_LABEL;
3000 if (chain->refcounted_he_keylen != 1)
3002 if (*REF_HE_KEY(chain) != ':')
3005 if ((STRLEN)HEK_LEN(chain->refcounted_he_hek) != 1)
3007 if (*HEK_KEY(chain->refcounted_he_hek) != ':')
3010 /* Stop anyone trying to really mess us up by adding their own value for
3012 if ((chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV
3013 && (chain->refcounted_he_data[0] & HVrhek_typemask) != HVrhek_PV_UTF8)
3017 *len = chain->refcounted_he_val.refcounted_he_u_len;
3019 *flags = ((chain->refcounted_he_data[0] & HVrhek_typemask)
3020 == HVrhek_PV_UTF8) ? SVf_UTF8 : 0;
3022 return chain->refcounted_he_data + 1;
3026 Perl_store_cop_label(pTHX_ COP *const cop, const char *label, STRLEN len,
3029 PERL_ARGS_ASSERT_STORE_COP_LABEL;
3031 if (flags & ~(SVf_UTF8))
3032 Perl_croak(aTHX_ "panic: store_cop_label illegal flag bits 0x%" UVxf,
3036 = refcounted_he_new_common(cop->cop_hints_hash, ":", 1, HVrhek_PV,
3037 flags & SVf_UTF8 ? HVrhek_PV_UTF8 : HVrhek_PV,
3042 =for apidoc hv_assert
3044 Check that a hash is in an internally consistent state.
3052 Perl_hv_assert(pTHX_ HV *hv)
3057 int placeholders = 0;
3060 const I32 riter = HvRITER_get(hv);
3061 HE *eiter = HvEITER_get(hv);
3063 PERL_ARGS_ASSERT_HV_ASSERT;
3065 (void)hv_iterinit(hv);
3067 while ((entry = hv_iternext_flags(hv, HV_ITERNEXT_WANTPLACEHOLDERS))) {
3068 /* sanity check the values */
3069 if (HeVAL(entry) == &PL_sv_placeholder)
3073 /* sanity check the keys */
3074 if (HeSVKEY(entry)) {
3075 NOOP; /* Don't know what to check on SV keys. */
3076 } else if (HeKUTF8(entry)) {
3078 if (HeKWASUTF8(entry)) {
3079 PerlIO_printf(Perl_debug_log,
3080 "hash key has both WASUTF8 and UTF8: '%.*s'\n",
3081 (int) HeKLEN(entry), HeKEY(entry));
3084 } else if (HeKWASUTF8(entry))
3087 if (!SvTIED_mg((const SV *)hv, PERL_MAGIC_tied)) {
3088 static const char bad_count[] = "Count %d %s(s), but hash reports %d\n";
3089 const int nhashkeys = HvUSEDKEYS(hv);
3090 const int nhashplaceholders = HvPLACEHOLDERS_get(hv);
3092 if (nhashkeys != real) {
3093 PerlIO_printf(Perl_debug_log, bad_count, real, "keys", nhashkeys );
3096 if (nhashplaceholders != placeholders) {
3097 PerlIO_printf(Perl_debug_log, bad_count, placeholders, "placeholder", nhashplaceholders );
3101 if (withflags && ! HvHASKFLAGS(hv)) {
3102 PerlIO_printf(Perl_debug_log,
3103 "Hash has HASKFLAGS off but I count %d key(s) with flags\n",
3108 sv_dump(MUTABLE_SV(hv));
3110 HvRITER_set(hv, riter); /* Restore hash iterator state */
3111 HvEITER_set(hv, eiter);
3118 * c-indentation-style: bsd
3120 * indent-tabs-mode: t
3123 * ex: set ts=8 sts=4 sw=4 noet: